lithium-chloride has been researched along with Disease-Models--Animal* in 259 studies
1 review(s) available for lithium-chloride and Disease-Models--Animal
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Overshadowing and latent inhibition of context aversion conditioning in the rat.
A review is presented of experimental studies, using rats as the subjects, that were designed to establish an animal model of the clinical phenomenon of anticipatory nausea. Experiments 1 and 2 demonstrated that pairing a distinctive context with an illness-inducing injection of lithium chloride endowed the context with new properties, consistent with the proposal that classical conditioning had established an association between the context as the conditioned stimulus and nausea as the unconditioned stimulus. The conditioned response to the context constitutes a form of anticipatory nausea. Experiment 3 examined overshadowing, showing that the presence of a novel salient cue (a flavour) during context conditioning reduced the magnitude of the aversion conditioned to the context. Experiments 4-7 examined the effects of giving exposure to the context prior to conditioning. They demonstrated a latent inhibition effect, that is, a reduction in the magnitude of the aversion in pre-exposed animals. It is suggested that these ways of modulating conditioned aversions could form the basis of interventions for use in the chemotherapy clinic. Anticipatory nausea is assumed to be a consequence of the formation of an association between the cues that constitute the clinic and the drug-induced nausea experienced in their presence. By restricting the development of this association, latent inhibition and overshadowing procedures should be effective in alleviating the problem of anticipatory nausea. Topics: Animals; Avoidance Learning; Conditioning, Classical; Disease Models, Animal; Humans; Lithium Chloride; Nausea; Rats; Taste; Vomiting, Anticipatory | 2006 |
258 other study(ies) available for lithium-chloride and Disease-Models--Animal
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Evaluation of in vivo lithium chloride effects as a GSK3-β inhibitor on human adipose derived stem cells differentiation into oligodendrocytes and re-myelination in an animal model of multiple sclerosis.
The application of neuroprotective agents in combination with stem cells is considered a potential effective treatment for multiple sclerosis (MS). Therefore, the effects of lithium chloride as a neuroprotective agent and a GSK3-β inhibitor were evaluated in combination with human adipose derived stem cells on re-myelination, oligodendrocyte differentiation, and functional recovery.. After inducing a mouse model of MS and proving it by the hanging wire test, the mice were randomly assigned to five experimental groups: Cup, Sham, Li, hADSC, and Li + hADSC. Additionally, a control group with normal feeding was considered. Finally, toluidine blue staining was carried out to estimate the level of myelination. Furthermore, immunofluorescent staining was used to evaluate the mean of OLIG2 and MOG positive cells. The mRNA levels of β-Catenin, myelin and oligodendrocyte specific genes were determined via the Real-Time PCR.. The results of the hanging wire test and toluidine blue staining showed a significant increase in myelin density and improvements in motor function in groups, which received lithium and stem cells, particularly in the Li + hADSC group compared with the untreated groups (P < 0.01). Moreover, immunostaining results indicated that the mean percentages of MOG and OLIG2 positive cells were significantly higher in the Li + hADSC group than in the other groups (P < 0.01). Finally, gene expression studies indicated that the use of lithium could increase the expression of β-Catenin, myelin and oligodendrocyte specific genes.. The use of Lithium Chloride can increase stem cells differentiation into oligodendrocytes and improve re-myelination in MS. Topics: Animals; beta Catenin; Cell Differentiation; Disease Models, Animal; Enzyme Inhibitors; Glycogen Synthase Kinase 3; Humans; Lithium; Lithium Chloride; Mice; Mice, Inbred C57BL; Multiple Sclerosis; Oligodendroglia; Stem Cells; Tolonium Chloride | 2023 |
Snail regulation in fibroblast-like synoviocytes by a histone deacetylase or glycogen synthase kinase inhibitor affects cell proliferation and gene expression.
Snail has been linked to the pathogenesis of rheumatoid arthritis (RA). We plan to investigate the regulation of Snail in response to TNF-α, histone acetylation, and glycogen synthase kinase-3 (GSK)-3 inhibition in fibroblast-like synoviocytes (FLSs).. FLSs from rats with collagen-induced arthritis (CIA) were collected and treated with TNF-α alone or a combination with trichostatin A (TSA), a pan-histone deacetylase inhibitor and lithium chloride (LiCl), a glycogen synthase kinase-3 (GSK)-3 inhibitor.. We demonstrated for the first time that nuclear expression of Snail in FLSs from rats with CIA was correlated with the levels of extracellular TNF-α and acetylation status. Cell proliferation and viability of CIA FLSs were reduced in response to TSA treatment and short-hairpin RNA specific to Snail. LiCl treatment increased Snail and cadherin-11 (Cad-11) expression in CIA FLSs.. We suggested from this study that targeting TNF-α-histone deacetylase-Snail signaling axis or the Wnt signaling pathway in FLSs might provide therapeutic interventions for the treatment of RA in the future. Topics: Acetylation; Animals; Arthritis, Experimental; Cell Proliferation; Cell Survival; Cells, Cultured; Disease Models, Animal; Fibroblasts; Gene Expression Regulation; Humans; Hydroxamic Acids; Lithium Chloride; Rats; Snail Family Transcription Factors; Synoviocytes; Tumor Necrosis Factor-alpha | 2021 |
Neuroprotective Effect of Intravitreal Single-Dose Lithium Chloride after Optic Nerve Injury in Rats.
Lithium is an old drug to control bipolar disorder. Moreover, it presents neuroprotective effects and supports neuronal plasticity. The aim of this study was to evaluate neuroprotective effect of intravitreal lithium after optic nerve injury.. Three dosages of lithium chloride, including 2 pmol, 200 pmol, and 2 nmol, were injected intravitreally after rat optic nerve injury. Proteins expression were assessed by western blot. Nitric oxide (NO) metabolites were measured by Griess test. Visual evoked potential (VEP) and optical coherence tomography (OCT) measurement were performed after trauma induction, in addition to H & E and TUJ1 staining of ganglion cells.. Western blot depicted lithium can significantly increase antiapoptotic Bcl-2 protein level and reduce. It seems intravitreally lithium has optic nerve neuroprotective effects by various mechanisms like overexpression of antiapoptotic proteins, suppressing proinflammatory molecules and proapoptotic factors, and decreasing nitric oxide. Topics: Animals; Antimanic Agents; Blotting, Western; Cell Survival; Disease Models, Animal; Evoked Potentials, Visual; Extracellular Signal-Regulated MAP Kinases; Intravitreal Injections; Lithium Chloride; Neuroprotective Agents; Nitric Oxide; Optic Nerve Injuries; Proto-Oncogene Proteins c-bcl-2; Rats; Rats, Wistar; Retinal Ganglion Cells; Toll-Like Receptor 4; Tomography, Optical Coherence | 2021 |
Deciphering key regulators involved in epilepsy-induced cardiac damage through whole transcriptome and proteome analysis in a rat model.
Sudden unexpected death in epilepsy (SUDEP) is a major outcome of cardiac dysfunction in patients with epilepsy. In continuation of our previous work, the present study was envisaged to explore the key regulators responsible for cardiac damage associated with chronic seizures using whole transcriptome and proteome analysis in a rat model of temporal lobe epilepsy.. A standard lithium-pilocarpine protocol was used to induce recurrent seizures in rats. The isolated rat heart tissue was subjected to transcriptomic and proteomic analysis. An integrated approach of RNA-Seq, proteomics, and system biology analysis was used to identify key regulators involved in seizure-linked cardiac changes. The analyzed differential expression patterns and network interactions were supported by gene and protein expression studies.. Altogether, 1157 differentially expressed genes and 1264 proteins were identified in the cardiac tissue of epileptic animals through RNA-Seq and liquid chromatography with tandem mass spectrometry-based proteomic analysis, respectively. The network analysis revealed seven critical genes-STAT3, Myc, Fos, Erbb2, Erbb3, Notch1, and Mapk8-that could play a role in seizure-mediated cardiac changes. The LC-MS/MS analysis supported the activation of the transforming growth factor β (TGF-β) pathway in the heart of epileptic animals. Furthermore, our gene and protein expression studies established a key role of STAT3, Erbb, and Mapk8 to develop cardiac changes linked with recurrent seizures.. The present multi-omics study identified STAT3, Mapk8, and Erbb as key regulators involved in seizure-associated cardiac changes. It provided a deeper understanding of molecular, cellular, and network-level operations of the identified regulators that lead to cardiac changes in epilepsy. Topics: Animals; Chromatography, Liquid; Disease Models, Animal; Epilepsy; Gene Expression Profiling; Gene Regulatory Networks; Heart Diseases; Lithium Chloride; Mitogen-Activated Protein Kinase 8; Muscarinic Agonists; Myocardium; Pilocarpine; Proteome; Proteomics; Proto-Oncogene Proteins c-fos; Proto-Oncogene Proteins c-myc; Rats; Real-Time Polymerase Chain Reaction; Receptor, ErbB-2; Receptor, ErbB-3; Receptor, Notch1; RNA-Seq; Signal Transduction; STAT3 Transcription Factor; Tandem Mass Spectrometry; Time Factors; Transforming Growth Factor beta | 2021 |
Cognitive effects of the GSK-3 inhibitor "lithium" in LPS/chronic mild stress rat model of depression: Hippocampal and cortical neuroinflammation and tauopathy.
Low-dose repeated lipopolysaccharide pre-challenge followed by chronic mild stress (LPS/CMS) protocol has been introduced as a rodent model of depression combining the roles of immune activation and chronic psychological stress. However, the impact of this paradigm on cognitive functioning has not been investigated hitherto.. This study evaluated LPS/CMS-induced cognitive effects and the role of glycogen synthase kinase-3β (GSK-3β) activation with subsequent neuroinflammation and pathological tau deposition in the pathogenesis of these effects using lithium (Li) as a tool for GSK-3 inhibition.. LPS pre-challenge reduced CMS-induced neuroinflammation, depressive-like behavior and cognitive inflexibility. It also improved spatial learning but increased GSK-3β expression and exaggerated hyperphosphorylated tau accumulation in hippocampus and prefrontal cortex. Li ameliorated CMS and LPS/CMS-induced depressive and cognitive deficits, reduced GSK-3β over-expression and tau hyperphosphorylation, impeded neuroinflammation and enhanced neuronal survival.. This study draws attention to LPS/CMS-triggered cognitive changes and highlights how prior low-dose immune challenge could develop an adaptive capacity to buffer inflammatory damage and maintain the cognitive abilities necessary to withstand threats. This work also underscores the favorable effect of Li (as a GSK-3β inhibitor) in impeding exaggerated tauopathy and neuroinflammation, rescuing neuronal survival and preserving cognitive functions. Yet, further in-depth studies utilizing different low-dose LPS challenge schedules are needed to elucidate the complex interactions between immune activation and chronic stress exposure. Topics: Animals; Behavior, Animal; Cerebral Cortex; Chronic Disease; Cognition; Cognitive Dysfunction; Depression; Disease Models, Animal; Encephalitis; Glycogen Synthase Kinase 3 beta; Hippocampus; Inflammation Mediators; Lipopolysaccharides; Lithium Chloride; Male; Phosphorylation; Protein Kinase Inhibitors; Rats, Wistar; Spatial Learning; Stress, Psychological; tau Proteins; Tauopathies | 2021 |
Chaihu-Longgu-Muli Decoction exerts an antiepileptic effect in rats by improving pyroptosis in hippocampal neurons.
Chaihu-Longgu-Muli Decoction (CLMD) is a classic prescription created by Zhong-jing Zhang, a famous ancient Chinese medical scientist, to harmonize uncontrollable body activities and calm the minds. Now Traditional Chinese Medicine (TCM) physicians often apply it to treat psychiatric diseases such as epilepsy.. This study investigated the mechanism of the effect of Chaihu-Longgu-Muli Decoction (CLMD) on hippocampal neurons pyroptosis in rats with Temporal Lobe Epilepsy (TLE).. The lithium chloride-pilocarpine-induced TLE rat model was established. The behavioral testing was performed and, the expression of IL-1β and TNF-α in serum was detected by ELISA, qRT-PCR was used to detect the mRNA expression of NLRP3, Caspase-1, IL-1β and TNF-α in hippocampus. The expression of NLRP3 and Caspase-1 in hippocampal dentate gyrus was detected by immunofluorescence assay.. CLMD could significantly suppress the frequency and duration time of epileptic seizures, reduce the expression of NLRP3, Caspase-1 TNF-α and IL-1β.. CLMD exerted an obvious antiepileptic effect by improving pyroptosis in hippocampal neurons of TLE rats. Topics: Animals; Anticonvulsants; Cytoskeletal Proteins; Disease Models, Animal; Drugs, Chinese Herbal; Epilepsy, Temporal Lobe; Hippocampus; Interleukin-1beta; Lithium Chloride; Male; Neurons; NLR Family, Pyrin Domain-Containing 3 Protein; Pilocarpine; Pyroptosis; Rats, Sprague-Dawley; Tumor Necrosis Factor-alpha | 2021 |
Alkaline brain pH shift in rodent lithium-pilocarpine model of epilepsy with chronic seizures.
Brain pH is thought to be important in epilepsy. The regulation of brain pH is, however, still poorly understood in animal models of chronic seizures (SZ) as well as in patients with intractable epilepsy. We used chemical exchange saturation transfer (CEST) MRI to noninvasively determine if the pH is alkaline shifted in a rodent model of the mesial temporal lobe (MTL) epilepsy with chronic SZ. Taking advantage of its high spatial resolution, we determined the pH values in specific brain regions believed to be important in this model produced by lithium-pilocarpine injection. All animals developed status epilepticus within 90 min after the lithium-pilocarpine administration, but one animal died within 24 hrs. All the surviving animals developed chronic SZ during the first 2 months. After SZ developed, brain pH was determined in the pilocarpine and control groups (n = 8 each). Epileptiform activity was documented in six pilocarpine rats with scalp EEG. The brain pH was estimated using two methods based on magnetization transfer asymmetry and amide proton transfer ratio. The pH was alkaline shifted in the pilocarpine rats (one outlier excluded) compared to the controls in the hippocampus (7.29 vs 7.17, t-test, p < 0.03) and the piriform cortex (7.34 vs. 7.06, p < 0.005), marginally more alkaline in the thalamus (7.13 vs. 7.01, p < 0.05), but not in the cerebral cortex (7.18 vs. 7.08, p > 0.05). Normalizing the brain pH may lead to an effective non-surgical method for treating intractable epilepsy as it is known that SZ can be eliminated by lowering the pH. Topics: Animals; Brain; Brain Chemistry; Convulsants; Disease Models, Animal; Drug Resistant Epilepsy; Epilepsy, Temporal Lobe; Hydrogen-Ion Concentration; Lithium Chloride; Male; Pilocarpine; Rats; Rats, Sprague-Dawley | 2021 |
Lithium chloride represses abdominal aortic aneurysm via regulating GSK3β/SIRT1/NF-κB signaling pathway.
Topics: Animals; Aortic Aneurysm, Abdominal; Disease Models, Animal; Glycogen Synthase Kinase 3 beta; Lithium Chloride; NF-kappa B; Rats; Signal Transduction; Sirtuin 1 | 2021 |
Effect of Experimental Fanconi Syndrome on Tubular Reabsorption of Lithium in Rats.
Lithium, administered to patients of bipolar disorders, is mainly excreted into urine, and tubular reabsorption at the proximal tubule is involved in the renal handling of lithium. In this study, we examined the renal excretion of lithium in rats with Fanconi syndrome, characterized by defects of transports of various compounds at the proximal tubules, induced by maleic acid. After maleic acid was intravenously injected, mannitol and lithium chloride were infused in turn. Using samples of plasma and bladder urine during the mannitol infusion, renal parameters were determined. Pharmacokinetic parameters of lithium were obtained using samples during the lithium chloride infusion. Maleic acid decreased creatinine clearance and increased the fractional excretion of glucose and phosphate, suggesting the induction of Fanconi syndrome. In rats with Fanconi syndrome, plasma concentration of lithium was increased, and its renal clearance was decreased. No effect on the fractional excretion of lithium was exhibited. This study represents that the tubular reabsorption of lithium was impaired to the same degree with glomerular filtration in rats with experimental Fanconi syndrome and that the dysfunction of the tubular reabsorption of glucose and phosphate was more severe. It is possible that Fanconi syndrome inhibited the reabsorption of lithium at the proximal tubule and facilitated the reabsorption of lithium from the loop of Henle to the collecting duct. Topics: Animals; Antimanic Agents; Creatinine; Disease Models, Animal; Fanconi Syndrome; Glucose; Injections, Intravenous; Kidney Tubules, Proximal; Lithium Chloride; Male; Maleates; Phosphates; Rats; Rats, Wistar | 2021 |
Pharmacological rescue of cognitive function in a mouse model of chemobrain.
After chemotherapy, many cancer survivors suffer from long-lasting cognitive impairment, colloquially known as "chemobrain." However, the trajectories of cognitive changes and the underlying mechanisms remain unclear. We previously established paclitaxel-induced inositol trisphosphate receptor (InsP3R)-dependent calcium oscillations as a mechanism for peripheral neuropathy, which was prevented by lithium pretreatment. Here, we investigated if a similar mechanism also underlay paclitaxel-induced chemobrain.. Mice were injected with 4 doses of 20 mg/kg paclitaxel every other day to induced cognitive impairment. Memory acquisition was assessed with the displaced object recognition test. The morphology of neurons in the prefrontal cortex and the hippocampus was analyzed using Golgi-Cox staining, followed by Sholl analyses. Changes in protein expression were measured by Western blot.. Mice receiving paclitaxel showed impaired short-term spatial memory acquisition both acutely 5 days post injection and chronically 23 days post injection. Dendritic length and complexity were reduced in the hippocampus and the prefrontal cortex after paclitaxel injection. Concurrently, the expression of protein kinase C α (PKCα), an effector in the InsP3R pathway, was increased. Treatment with lithium before or shortly after paclitaxel injection rescued the behavioral, cellular, and molecular deficits observed. Similarly, memory and morphological deficits could be rescued by pretreatment with chelerythrine, a PKC inhibitor.. We establish the InsP3R calcium pathway and impaired neuronal morphology as mechanisms for paclitaxel-induced cognitive impairment. Our findings suggest lithium and PKC inhibitors as candidate agents for preventing chemotherapy-induced cognitive impairment. Topics: Animals; Antineoplastic Agents, Phytogenic; Chemotherapy-Related Cognitive Impairment; Cognition; Disease Models, Animal; Female; Inositol 1,4,5-Trisphosphate Receptors; Lithium Chloride; Mice; Mice, Inbred C57BL; Neuroprotective Agents; Paclitaxel | 2021 |
Therapeutic candidates for the Zika virus identified by a high-throughput screen for Zika protease inhibitors.
When Zika virus emerged as a public health emergency there were no drugs or vaccines approved for its prevention or treatment. We used a high-throughput screen for Zika virus protease inhibitors to identify several inhibitors of Zika virus infection. We expressed the NS2B-NS3 Zika virus protease and conducted a biochemical screen for small-molecule inhibitors. A quantitative structure-activity relationship model was employed to virtually screen ∼138,000 compounds, which increased the identification of active compounds, while decreasing screening time and resources. Candidate inhibitors were validated in several viral infection assays. Small molecules with favorable clinical profiles, especially the five-lipoxygenase-activating protein inhibitor, MK-591, inhibited the Zika virus protease and infection in neural stem cells. Members of the tetracycline family of antibiotics were more potent inhibitors of Zika virus infection than the protease, suggesting they may have multiple mechanisms of action. The most potent tetracycline, methacycline, reduced the amount of Zika virus present in the brain and the severity of Zika virus-induced motor deficits in an immunocompetent mouse model. As Food and Drug Administration-approved drugs, the tetracyclines could be quickly translated to the clinic. The compounds identified through our screening paradigm have the potential to be used as prophylactics for patients traveling to endemic regions or for the treatment of the neurological complications of Zika virus infection. Topics: Animals; Antiviral Agents; Artificial Intelligence; Chlorocebus aethiops; Disease Models, Animal; Drug Evaluation, Preclinical; High-Throughput Screening Assays; Immunocompetence; Inhibitory Concentration 50; Methacycline; Mice, Inbred C57BL; Protease Inhibitors; Quantitative Structure-Activity Relationship; Small Molecule Libraries; Vero Cells; Zika Virus; Zika Virus Infection | 2020 |
Blackberry extract improves behavioral and neurochemical dysfunctions in a ketamine-induced rat model of mania.
Bipolar disorder is a chronic mood disorder characterized by episodes of mania and depression. The aim of this study was to investigate the effects of blackberry extract on behavioral parameters, oxidative stress and inflammatory markers in a ketamine-induced model of mania. Animals were pretreated with extract (200 mg/kg, once a day for 14 days), lithium chloride (45 mg/kg, twice a day for 14 days), or vehicle. Between the 8th and 14th days, the animals received an injection of ketamine (25 mg/kg) or vehicle. On the 15th day, thirty minutes after ketamine administration, the animals' locomotion was assessed using open-field apparatus. After the experiments, the animals were euthanized and cerebral structures were removed for neurochemical analyses. The results showed that ketamine treatment induced hyperlocomotion and oxidative damage in the cerebral cortex, hippocampus and striatum. In contrast, pretreatment with the extract or lithium was able to prevent hyperlocomotion and oxidative damage in the cerebral cortex, hippocampus, and striatum. In addition, IL-6 and IL-10 levels were increased by ketamine, while the extract prevented these effects in the cerebral cortex. Pretreatment with the extract was also effective in decreasing IL-6 and increasing the level of IL-10 in the striatum. In summary, our findings suggest that blackberry consumption could help prevent or reduce manic episodes, since this extract have demonstrated neuroprotective properties as well as antioxidant and anti-inflammatory effects in the ketamine-induced mania model. Topics: Animals; Anthocyanins; Antimanic Agents; Behavior, Animal; Catalase; Cerebral Cortex; Cytokines; Disease Models, Animal; Excitatory Amino Acid Antagonists; Fruit; Glutathione Peroxidase; Hippocampus; Ketamine; Lithium Chloride; Mania; Neostriatum; Open Field Test; Plant Extracts; Rats; Rubus; Superoxide Dismutase; Thiobarbituric Acid Reactive Substances | 2020 |
Lithium attenuates d-amphetamine-induced hyperlocomotor activity in mice via inhibition of interaction between cyclooxygenase-2 and indoleamine-2,3-dioxygenase.
In the present study, we investigated whether mood stabilizer lithium (Li) protects against d-amphetamine (AMP)-induced mania-like behaviours via modulating the novel proinflammatory potential. Repeated treatment with AMP resulted in significant increases in proinflammatory cyclooxygenase-2 (COX-2) and indolemaine-2,3-dioxygenase-1 (IDO)-1 expression in the prefrontal cortex (PFC) of mice. However, AMP treatment did not significantly change IDO-2 and 5-lipoxygenase (5-LOX) expression, suggesting that proinflammatory parameters such as COX-2 and IDO-1 are specific for AMP-induced behaviours. AMP-induced initial expression of COX-2 (15 minutes post-AMP) was earlier than that of IDO-1 (1 hour post-AMP). Mood stabilizer Li and COX-2 inhibitor meloxicam significantly attenuated COX-2 expression 15 minutes post-AMP, whereas IDO-1 inhibitor 1-methyl-DL-tryptophan (1-MT) did not affect COX-2 expression. However, AMP-induced IDO-1 expression was significantly attenuated by Li, meloxicam or 1-MT, suggesting that COX-2 is an upstream molecule for the induction of IDO-1 caused by AMP. Consistently, co-immunoprecipitation between COX-2 and IDO-1 was observed at 30 minutes, 1, 3, and 6 hours after the final AMP treatment. This interaction was also significantly inhibited by Li, meloxicam or 1-MT. Furthermore, AMP-induced hyperlocomotion was significantly attenuated by Li, meloxicam or 1-MT. We report, for the first time, that mood stabilizer Li attenuates AMP-induced mania-like behaviour via attenuation of interaction between COX-2 and IDO-1, and that the interaction of COX-2 and IDO-1 may be critical for the therapeutic intervention mediated by mood stabilizer. Topics: Amphetamine; Animals; Antimanic Agents; Behavior, Animal; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Disease Models, Animal; Indoleamine-Pyrrole 2,3,-Dioxygenase; Lithium Chloride; Locomotion; Male; Mania; Meloxicam; Mice, Inbred C57BL; Prefrontal Cortex; Signal Transduction; Tryptophan | 2020 |
The implications of hippocampal neurogenesis in adolescent rats after status epilepticus: a novel role of notch signaling pathway in regulating epileptogenesis.
Seizure-induced neurogenesis has a widely recognized pro-epileptogenic function. Given the critical role of Notch signaling during the maintenance and neurogenesis of neural stem cells, we hypothesized that Notch may affect epileptogenesis and its progression through its role in neurogenesis in the adolescent rat brain. We used the lithium-pilocarpine-induced epilepsy model in adolescent Sprague-Dawley rats in order to evaluate hippocampal neurogenesis and epileptogenesis following the onset of status epilepticus (SE). We used western blotting analyses and qPCR to measure levels of Notch signaling at different phases after seizures and immunofluorescence to detect the proliferation and differentiation of neural stem cells after seizure. Following the administration of DAPT, a Notch γ-secretase inhibitor, into the lateral ventricles, we observed a suppression of abnormal neurogenesis in the acute phase and a reduction of gliosis in the chronic phase after SE. Accordingly, the frequency and duration of spontaneous seizures in chronic phase were decreased. Our results clarify the basic concept regarding the involvement of Notch signaling in the regulation of hippocampal neurogenesis and epileptogenesis, thereby potentially offering a novel and alternative treatment for epilepsy. Topics: Animals; Cell Differentiation; Disease Models, Animal; Epilepsy; Hippocampus; Lithium Chloride; Neural Stem Cells; Neurogenesis; Pilocarpine; Rats; Rats, Sprague-Dawley; Receptor, Notch1; Signal Transduction; Status Epilepticus | 2020 |
Differential effects of lithium isotopes in a ketamine-induced hyperactivity model of mania.
Sub-anesthetic doses of ketamine produce an increase in rodent ambulation that is attenuated by co-administration of naturally-occurring lithium (LiN), the drug most commonly employed in the treatment of bipolar illness. As a consequence, ketamine-induced hyperactivity has been proposed as an animal model of manic behavior. The current study employed a modified version of this model to compare the potency of LiN to that of each of its two stable isotopes - lithium-6 (Li-6) and lithium-7 (Li-7). Since Li-7 constitutes 92.4% of the parent compound it was hypothesized to produce comparable behavioral effects to that of LiN. The current study was devised to determine whether Li-6 might be more, less, or equally effective at tempering hyperactivity relative to Li-7 or to LiN in an animal model of manic behavior. Male rats were maintained on a restricted but high-incentive diet containing a daily dose of 2.0 mEq/kg of lithium (LiN), Li-6 or Li-7 for 30 days. A control group consumed a diet infused with sodium chloride (NaCl) in place of lithium to control for the salty taste of the food. On day 30, baseline testing revealed no differences in the locomotor behavior among the four treatment groups. Animals then continued their Li/NaCl diets for an additional 11 days during which every subject received a single IP injection of either ketamine (25 mg/kg) or 0.9% physiological saline. On the final four days of this regimen, locomotor activity was assessed during 60 min sessions each beginning immediately after ketamine injection. While all three lithium groups produced comparable decreases in ketamine-induced hyperactivity on the first trial, by the fourth trial Li-6 animals exhibited significantly greater and more prolonged reductions in hyperactivity compared to either Li-7 and Li. These results suggest that Li-6 may be more effective at treating mania than its parent compound. Topics: Animals; Antimanic Agents; Behavior, Animal; Disease Models, Animal; Isotopes; Ketamine; Lithium; Lithium Chloride; Locomotion; Male; Mania; Rats; Rats, Sprague-Dawley; Treatment Outcome | 2020 |
Lithium chloride confers protection against viral myocarditis via suppression of coxsackievirus B3 virus replication.
Viral myocarditis (VMC) is a type of inflammation affecting myocardial cells caused by viral infection and has been an important cause of dilated cardiomyopathy (DCM) worldwide. Type B3 coxsackievirus (CVB3), a non-enveloped positive-strand RNA virus of the Enterovirus genus, is one of most common agent of viral myocarditis. Till now, effective treatments for VMC are lacking due to lack of drugs or vaccine. Lithium chloride (LiCl) is applied in the clinical management of manic depressive disorders. Accumulating evidence have demonstrated that LiCl, also as an effective antiviral drug, exhibited antiviral effects for specific viruses. However, there are few reports of evaluating LiCl's antiviral effect in mice model. Here, we investigated the inhibitory influence of LiCl on the CVB3 replication in vitro and in vivo and the development of CVB3-induced VMC. We found that LiCl significantly suppressed CVB3 replication in HeLa via inhibiting virus-induced cell apoptosis. Moreover, LiCl treatment in vivo obviously inhibited virus replication within the myocardium and alleviated CVB3-induced acute myocarditis. Collectively, our data demonstrated that LiCl inhibited CVB3 replication and negatively regulated virus-triggered inflammatory responses. Our finding further expands the antiviral targets of LiCl and provides an alternative agent for viral myocarditis. Topics: Animals; Antiviral Agents; Apoptosis; Cardiomyopathy, Dilated; Cell Line; Coxsackievirus Infections; Disease Models, Animal; Drug Repositioning; Enterovirus B, Human; HEK293 Cells; HeLa Cells; Humans; Lithium Chloride; Male; Mice; Mice, Inbred BALB C; Myocarditis; Myocardium; Virus Replication | 2020 |
Chloroquine attenuates lithium-induced NDI and proliferation of renal collecting duct cells.
Lithium is widely used in psychiatry as the golden standard for more than 60 yr due to its effectiveness. However, its adverse effect has been limiting its long-term use in clinic. About 40% of patients taking lithium develop nephrogenic diabetes insipidus (NDI). Lithium can also induce proliferation of collecting duct cells, leading to microcyst formation in the kidney. Lithium was considered an autophagy inducer that might contribute to the therapeutic benefit of neuropsychiatric disorders. Thus, we hypothesized that autophagy may play a role in lithium-induced kidney nephrotoxicity. To address our hypothesis, we fed mice with a lithium-containing diet with chloroquine (CQ), an autophagy inhibitor, concurrently. Lithium-treated mice presented enhanced autophagy activity in the kidney cortex and medulla. CQ treatment significantly ameliorated lithium-induced polyuria, polydipsia, natriuresis, and kaliuresis accompanied with attenuated downregulation of aquaporin-2 and Na Topics: Animals; Aquaporin 2; Autophagy; beta Catenin; Cell Line; Cell Proliferation; Chloroquine; Diabetes Insipidus, Nephrogenic; Dinoprostone; Disease Models, Animal; Kidney Tubules, Collecting; Lithium Chloride; Male; Mice, 129 Strain; Natriuresis; Phosphorylation; Polyuria; Solute Carrier Family 12, Member 1; Thiobarbituric Acid Reactive Substances; TOR Serine-Threonine Kinases | 2020 |
Chaihu-Longgu-Muli decoction relieves epileptic symptoms by improving autophagy in hippocampal neurons.
Chaihu-Longgu-Muli decoction (CLMD) is a well-known ancient formula in traditional Chinese medicine (TCM) to relieve disorder, clear away heat, tranquilize the mind and allay excitement. It has been used for the therapy of neuropsychiatric disorders such as epilepsy, dementia, insomnia, anxiety, and depression for several centuries in China.. This paper is based on the assumption that the mechanism by which CLMD relieves epileptic symptoms in rats is associated with improving autophagy. Several experimental methods are designed to testify the hypothesis.. The lithium-pilocarpine-induced epilepsy model was established in rats. The seizure frequency was recorded. Morphology and number of autophagosomes in hippocampal dentate gyrus was detected with a transmission electron microscope (TEM). Expression of Beclin-1, microtubule-associated proteins 1A/1B light chain 3 (LC3), and mammalian target of rapamycin (mTOR) in dentate gyrus was measured by immunofluorescence assay, quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western-blotting.. CLMD could significantly relieve the seizure frequency and improve autophagy in hippocampal dentate gyrus. Meanwhile, the level of Beclin-1 and LC3B decreased significantly, while mTOR increased remarkably after medical intervention.. CLMD could improve autophagy in hippocampal dentate gyrus due to epilepsy, especially at high dose. The mechanism may be related to upregulated expression of mTOR and downregulated expression of Beclin-1 and LC3B. Topics: Animals; Anticonvulsants; Autophagosomes; Autophagy; Autophagy-Related Proteins; Behavior, Animal; Disease Models, Animal; Drugs, Chinese Herbal; Epilepsy; Hippocampus; Lithium Chloride; Male; Neurons; Pilocarpine; Rats, Sprague-Dawley; Signal Transduction | 2020 |
Potent Inhibition of Biphasic Tubular Reabsorption of Lithium by Acetazolamide and Foscarnet in Rats.
Lithium is mainly excreted into urine, and a large fraction of lithium filtered through glomeruli is reabsorbed in the proximal tubule. However, the mechanisms responsible for lithium reabsorption remain unclear. We previously reported that the reabsorption of lithium was biphasic in rats, and that foscarnet inhibited lithium reabsorption with a high affinity type. We herein evaluated the effects of acetazolamide and foscarnet on the renal excretion of lithium in rats treated with lithium chloride at 2 doses. In rats intravenously injected with a bolus of 25 mg/kg lithium chloride, acetazolamide facilitated the urinary excretion of lithium, and increased the fractional excretion of lithium from 0.446 to 0.953, near the theoretically maximum value. At a dose of 2.5 mg/kg lithium chloride, the fractional excretion of lithium was 0.241 in control rats, 0.420 in rats administered acetazolamide, and 0.976 in rats administered acetazolamide and foscarnet. These results showed the potent inhibition of lithium reabsorption by acetazolamide and foscarnet in rats. And, it was exhibited that the effects of acetazolamide on lithium reabsorption differed with the dosages of lithium administered. Topics: Acetazolamide; Animals; Antiviral Agents; Disease Models, Animal; Diuretics; Drug Interactions; Foscarnet; Kidney Tubules, Proximal; Lithium Chloride; Male; Rats; Rats, Wistar; Renal Reabsorption | 2020 |
Effects of the putative lithium mimetic ebselen on pilocarpine-induced neural activity.
Lithium, commonly used to treat bipolar disorder, potentiates the ability of the muscarinic agonist pilocarpine to induce seizures in rodents. As this potentiation by lithium is reversed by the administration of myo-inositol, the potentiation may be mediated by inhibition of inositol monophosphatase (IMPase), a known target of lithium. Recently, we demonstrated that ebselen is a 'lithium mimetic' in regard to behaviours in both mice and man. Ebselen inhibits IMPase in vitro and lowers myo-inositol in vivo in the brains of mice and men, making ebselen the only known inhibitor of IMPase, other than lithium, that penetrates the blood-brain barrier. Our objective was to determine the effects of ebselen on sensitization to pilocarpine-induced seizures and neural activity. We administered ebselen at different doses and time intervals to mice, followed by injection of a sub-seizure dose of pilocarpine. We assessed seizure and neural activity by a subjective seizure rating scale, by monitoring tremors, and by induction of the immediate early gene c-fos. In contrast to lithium, ebselen did not potentiate the ability of pilocarpine to induce seizures. Unexpectedly, ebselen inhibited pilocarpine-induced tremor as well as pilocarpine-induced increases in c-fos mRNA levels. Both lithium and ebselen inhibit a common target, IMPase, but only lithium potentiates pilocarpine-induced seizures, consistent with their polypharmacology at diverse molecular targets. We conclude that ebselen does not potentiate pilocarpine-induced seizures and instead, reduces pilocarpine-mediated neural activation. This lack of potentiation of muscarinic sensitization may be one reason for the lack of side-effects observed with ebselen treatment clinically. Topics: Animals; Anticonvulsants; Azoles; Brain; Calcium Signaling; CHO Cells; Cricetulus; Disease Models, Animal; Inositol Phosphates; Isoindoles; Lithium Chloride; Male; Mice; Neurons; Organoselenium Compounds; Phosphoric Monoester Hydrolases; Pilocarpine; Proto-Oncogene Proteins c-fos; Receptors, Muscarinic; Seizures | 2020 |
Inhibition of natriuretic peptide receptor 1 reduces itch in mice.
There is a major clinical need for new therapies for the treatment of chronic itch. Many of the molecular components involved in itch neurotransmission are known, including the neuropeptide NPPB, a transmitter required for normal itch responses to multiple pruritogens in mice. Here, we investigated the potential for a novel strategy for the treatment of itch that involves the inhibition of the NPPB receptor NPR1 (natriuretic peptide receptor 1). Because there are no available effective human NPR1 (hNPR1) antagonists, we performed a high-throughput cell-based screen and identified 15 small-molecule hNPR1 inhibitors. Using in vitro assays, we demonstrated that these compounds specifically inhibit hNPR1 and murine NPR1 (mNPR1). In vivo, NPR1 antagonism attenuated behavioral responses to both acute itch- and chronic itch-challenged mice. Together, our results suggest that inhibiting NPR1 might be an effective strategy for treating acute and chronic itch. Topics: Animals; Behavior, Animal; Cell-Free System; Dermatitis, Contact; Disease Models, Animal; Ganglia, Spinal; Humans; Mice, Inbred C57BL; Mice, Knockout; Neurons; Pruritus; Receptors, Atrial Natriuretic Factor; Reproducibility of Results; Signal Transduction; Small Molecule Libraries | 2019 |
Long-term impact of chronic variable stress in adolescence versus adulthood.
Adolescence is a period of active development of stress regulatory neurocircuitry. As a consequence, mechanisms that control the responses to stress are not fully matured during this developmental period, which may result in vulnerability to chronic stress. We hypothesized that adolescent chronic stress would have negative consequences on stress adaptation later in life. Male Wistar rats (PND40) were subjected to chronic variable stress (CVS) for 2 weeks, with 2 daily stressors randomly presented and overnight social stressors twice a week. After five weeks, animals were evaluated during adulthood, using the elevated plus maze (EPM) and the forced swim test (FST). The hypothalamic-pituitary adrenal (HPA) axis response to a 30-min restraint was also assessed. Results are compared to those of adult rats tested 5 weeks following CVS cessation. Our results demonstrate that the long-term effects of CVS are specific to the age of application of the stress regime. We show how behavior and HPA axis response as well as hypothalamic paraventricular nucleus activation can differ with age, resulting in differential behavioral adaptations for animals stressed in adolescence and dysregulation of the HPA axis in the animals stressed in adulthood, These data underscore the importance of the adolescent period in determining resilience of the HPA axis and programming behavioral responses later in life. Topics: Adrenocorticotropic Hormone; Age Factors; Animals; Antimanic Agents; Chronic Disease; Corticosterone; Disease Models, Animal; Exploratory Behavior; Lithium Chloride; Male; Maze Learning; Mice; Statistics, Nonparametric; Stress, Psychological; Swimming | 2019 |
Pore-former enabled seeding of tau in rats: Alleviation by memantine and lithium chloride.
Background Tauopathies, including Alzheimer's disease (AD), are multifactorial diseases with strong phenotypic and genetic heterogeneity. Recent evidence revealed that mechanisms of pathogenesis of early (hereditary) and late (sporadic) forms of AD are different. This is not properly reflected in current experimental models, especially when it comes to sporadic forms of AD. Here, we present novel seeding based model and explore its suitability for therapeutic intervention. New method We validate novel region specific approach to modelling Tau pathology reported by Koss and co-authors (2015). Wistar rats 3, 9 and 15 month-old were surgically prepared for hippocampal loading with pore-former polymeric 1,3-alkylpyridinium salts (Poly-APS) and recombinant human tau including pharmacological inhibition of phosphatase activity by okadaic acid co-administration. We explored whether tau seeding caused molecular and behavioural traits reminiscent of AD and explored their reversibility/prevention by administration of either memantine or lithium. Results The presented model emulates several changes observed in progressive dementia such as: heightened levels of tau and its hyperphosphorylation, changes in tau compartmentalization, breakdown of the cytoskeleton, cognitive impairments, and sensitivity for anti-dementia treatment. Comparison with existing methods Seeding has been achieved in transgenic mouse models, but this is the first rat model significantly mimicking cognitive and neuronal changes akin to tauopathies. Moreover, we have successfully included the factor age in our model and can show sensitivity to drug treatment. Conclusions These data validate a novel model of locally infused recombinant human Tau as an inducer of tauopathy in rats and holds the potential for development of novel therapies. Topics: Alzheimer Disease; Animals; CA1 Region, Hippocampal; Disease Models, Animal; Lithium Chloride; Male; Memantine; Neurons; Neuroprotective Agents; Phosphorylation; Polymers; Pyridinium Compounds; Rats, Wistar; Recombinant Proteins; tau Proteins; Tauopathies | 2019 |
Early endocannabinoid system activation attenuates behavioral impairments induced by initial impact but does not prevent epileptogenesis in lithium-pilocarpine status epilepticus model.
Mood and anxiety disorders, as well as memory impairments, are important factors affecting quality of life in patients with epilepsy and can influence the antiepileptic therapy. Clinical studies of psychiatric comorbidities are quite complicated to design and interpret, so animal studies of behavioral impairments associated with seizures can be of use. We investigated the effect of early administration of endocannabinoid receptor agonist WIN-55,212-2 on the development of spontaneous seizures, long-term behavioral and memory impairments, and neurodegeneration in the hippocampus on the lithium-pilocarpine model of status epilepticus (SE). We also studied the role of spontaneous seizures in the development of pathologic consequences of the SE. Our results showed that behavioral impairments found in the elevated plus maze test depended mostly on the consequences of SE itself and not on the development of spontaneous seizures while hyperactivity in the open-field test and light-dark chamber was more prominent in rats with spontaneous seizures. Administration of WIN-55,212-2 decreased emotional behavior in the elevated plus maze but did not affect hyperactive behavior in the open-field test. Spatial memory impairment developed both in the presence or absence of spontaneous seizures and was not affected by administration of WIN-55,212-2. Both administration of endocannabinoid receptor agonist WIN-55,212-2 and the presence of spontaneous seizures affected SE-induced neuronal loss in the hippocampus. Topics: Animals; Anticonvulsants; Benzoxazines; Disease Models, Animal; Endocannabinoids; Hippocampus; Lithium Chloride; Locomotion; Male; Maze Learning; Morpholines; Naphthalenes; Pilocarpine; Rats; Rats, Wistar; Seizures; Status Epilepticus | 2019 |
Downregulated hippocampal expression of brain derived neurotrophic factor and tyrosine kinase B in a rat model of comorbid epilepsy and depression.
To investigate the expression of brain-derived neurotrophic factor(BDNF) and tyrosine kinase B (TrkB) protein in the hippocampus of model rats of comorbid epilepsy and depression.. A rat model of epilepsy was established using lithium chloride.pilocarpine. Among these epileptic rats, those with comorbid depression were selected by a battery of behavioral tests starting on the 14th day after establishing the epilepsy model. A depression group was established by unpredicted chronic mild stress (UCMS) and separate housing. These treatment groups were compared to an untreated control group. Thirteen rats per group were examined by immunofluorescence staining with optical density quantitation to determine the distribution of BDNF- and TrkB-positive cells in the hippocampus and by western blotting to estimate total protein expression levels during the 4th week after establishing the models. Immunofluorescence staining for NeuN was also conducted in hippocampus to evaluate neuronal survival. Depression-like behaviors were also assessed.. Compared to the untreated control group and the epilepsy alone group, the comorbid group exhibited lower average optical densities of BDNF- and TrkB-immunopositive cells as well as lower total BDNF and TrkB protein expression levels (all P = 0.000). The comorbid group exhibited lower behavioral scores compared to all other groups (all P=0.000). Numbers of NeuN-positive cells were lower in the hippocampus of all three experimental groups compared to the untreated control group (all P = 0.000).. These results suggest that hypofunctional BDNF-TrkB signaling may contribute to depression in epilepsy.. BDNF: Brain-derived neurotrophic factor; TrkB: tyrosine kinase B; UCMS: unpredicted chronic mild stress; PBS: phosphate-buffered saline; HS: Hippocampal sclerosis. Topics: Animals; Brain-Derived Neurotrophic Factor; Cell Survival; Comorbidity; Depressive Disorder; Disease Models, Animal; Down-Regulation; Epilepsy; Female; Hippocampus; Lithium Chloride; Neurons; Pilocarpine; Random Allocation; Rats, Sprague-Dawley; Receptor, trkB | 2019 |
Decrease of GSK3β Ser-9 Phosphorylation Induced Osteoblast Apoptosis in Rat Osteoarthritis Model.
Nowadays, the cumulative intake of glucocorticoids has become the most common pathogenic factor for non-traumatic osteonecrosis of the femoral head (ONFH). Apoptosis of osteoblasts is considered as the main reason of ONFH at the molecular level. Glycogen synthase kinase 3β (GSK3β) is an important regulator of cellular differentiation and apoptosis pathway, which can modulate the balance between osteoblasts and osteoclasts. Several studies have reported about its function in osteoporosis, but little is known about it in osteonecrosis. In our study, lipopolysaccharide and methylprednisolone were utilized to establish a rat ONFH model. The phosphorylation of GSK3β Ser-9 was decreased in the model. Western blotting examination of β-catenin, Bcl-2, Bax and caspase-3 revealed that the osteoblasts were apoptotic. In dexamethasone (Dex)-incubated primary osteoblasts, the expression profile of GSK3β phosphorylation and apoptotic factors were consistent with those in the rat ONFH model. To further investigate the regulation of osteonecrosis caused by GSK3β, the expression and function of GSK3β were inhibited in Dex-incubated primary osteoblasts. The knockdown of GSK3β by siRNA decreased the expression of Bax and cleaved caspase-3, but increased Bcl-2 and β-catenin. On the other hand, selective inhibition of GSK3β function by LiCl counteracted the activation of caspase-3 induced by Dex. Our work is the first study about the GSK3β phosphorylation in ONFH, and provides evidence for further therapeutic methods. Topics: Animals; Apoptosis; Dexamethasone; Disease Models, Animal; Femur Head Necrosis; Gene Knockdown Techniques; Glycogen Synthase Kinase 3 beta; Lipopolysaccharides; Lithium Chloride; Methylprednisolone; Osteoarthritis; Osteoblasts; Phosphorylation; Rats; Serine; Up-Regulation | 2019 |
The effect of lithium chloride on BDNF, NT3, and their receptor mRNA levels in the spinal contusion rat models.
Nowadays, there seems to be no decisive way for treatment of spinal cord injury (SCI).Extensive cell death (apoptosis and necrosis) occurring in SCI can cause considerable progressive sensorimotor disabilities. Preventing cell death by improving endogenous regenerative capability could an effective strategy for the treatment of SCI. This study was designed to evaluate the effects of lithium chloride (LiCl) on the cell survival through overexpression of BDNF and NT3 mRNA level and their receptors in the contusion rat models.. Rats were randomly divided into four experimental groups (eight rats/group) including: contused animals (the non-treatment group); contused animals (the control group) which received laminectomy; contused animals received normal saline (vehicle)and contused animals received intraperitoneal injection of 20 mg/kg LiCl three days after surgery. Injection continued for 14 days as treatment. Basso, Beattie, Bresnahan (BBB) rating scale was used to assess the motor function of the rats. To evaluate the histopathological and gene expression analysis, rats were sacrificed 28 days after surgery. Real-time reverse transcriptase polymerase chain reaction (RT-PCR) was performed to obtain the relative levels of mRNA for BDNF, NT3 and their receptors.. The results showed LiCl ameliorates BBB scores via up-regulation of BDNF and TrkB receptors. Also, histological analysis showed that the numerical density per area of TUNEL- positive cells and the percentage of cavity significantly decreased in the LiCl-treated group.. Our findings suggest that LiCl protects neural cells and effectively enhances locomotor function, which was done through up-regulation of endogenous BDNF expression in rats with SCI.. SCI: spinal cord injury; LiCl: lithium chloride; BDNF: Brain-derived neurotrophic factor; NT3: Neurotrophin-3; BBB: Basso, Beattie, Bresnahan; TrkB: Tropomyosin receptor kinase B; TUNEL: Terminal deoxynucleotidyl transferase dUTP nick end labeling. Topics: Animals; Apoptosis; Brain-Derived Neurotrophic Factor; Contusions; Disease Models, Animal; Lithium Chloride; Motor Activity; Nerve Growth Factors; Neurotrophin 3; Rats, Sprague-Dawley; Recovery of Function; Spinal Cord; Spinal Cord Injuries | 2019 |
ADENOSINE A1 RECEPTOR AGONIST PROTECTS AGAINST HIPPOCAMPAL NEURONAL INJURY AFTER LITHIUM CHLORIDE-PILOCARPINE-INDUCED EPILEPSY.
Adenosine A1 receptor (AA1R) is widely present in the central nervous system, exerting brain protective antiepileptic effects, mainly by binding corresponding G proteins. We evaluated the neuroprotective effects of AA1R on hippocampal neuronal injury after lithium chloride-pilocarpine-induced epilepsy in rats.. A total of 60 male SD rats were randomly divided into four groups (n = 15/group): normal control, epilepsy, epilepsy + AA1R antagonist (DPCPX), and epilepsy + AA1R agonist (2-CAdo). An epilepsy model was established through kindling by lithium chloride-pilocarpine. The four groups were observed on days 1, 14, and 30. Pathological and morphological changes of hippocampal neurons were observed by HE staining; apoptosis was detected by TUNEL assay. Caspase-3 and GABA receptor expressions were detected by Western blot.. In the hippocampal CA3 area of the epilepsy group, the cellular structure was not neatly arranged, and some neurons were swelling, thick, and incomplete. Compared with the epilepsy group at the same time point, cells in the epilepsy + DPCPX group had an increased distortion, disorganization, edema, cytoplasmic vacuoles, and degeneration. In the epilepsy + 2-CAdo group, cell arrangement was regular and orderly, and structural damages were lessened. Compared with the normal control group at the same time point, the epilepsy group underwent evident neuronal apoptosis, with a significantly higher apoptotic index (AI) (p < 0.05). Compared with the epilepsy group, the neuronal apoptosis of the epilepsy + DPCPX group was boosted, and the AI significantly increased (p < 0.05). The neuronal apoptosis of the epilepsy + 2-CAdo group was inhibited, and the AI significantly decreased (p < 0.05). Compared with the epilepsy group, the caspase-3 expression levels of the epilepsy + DPCPX group on days 14 and 30 were significantly upregulated (p < 0.05), but those of the epilepsy + 2-CAdo group were significantly downregulated (p < 0.05).. AA1R abated cell edema and reduced apoptosis, exerting neuroprotective effects on hippocampal neuronal injury after lithium chloride-pilocarpine-induced epilepsy. Topics: Adenosine A1 Receptor Agonists; Animals; Apoptosis; Disease Models, Animal; Epilepsy; Hippocampus; Lithium Chloride; Male; Neurons; Neuroprotective Agents; Pilocarpine; Rats; Rats, Sprague-Dawley; Time Factors | 2019 |
Enhancing autophagy by down-regulating GSK-3β alleviates cisplatin-induced ototoxicity in vivo and in vitro.
Previous study reported that either selective GSK-3β inhibitor or up-regulating autophagy can alleviate cisplatin-induced ototoxicity. Other studies indicate that the activity of GSK-3β is closely associated with the autophagy level. The purpose of this study is to primarily explore the role of autophagy in the alleviation effect of GSK-3β inhibition on cisplatin-induced ototoxicity in vivo and in vitro. We observed the autophagy changes induced by GSK-3β inhibitor in outer hair cells (OHCs) in a cisplatin-induced ototoxicity rat model. In addition, autophagy inhibitor 3-MA was used in vitro experiments to observe the influence of autophagy inhibition on the cell protection effect due to GSK-3β inactivation. The relationship among autophagy, GSK-3β and cell damage were inferred. Negative regulation of GSK-3β significantly enhanced autophagy and alleviated cisplatin-induced hearing loss, OHC death in vivo and apoptosis in vitro. The autophagy inhibitor 3-MA inverted the protective effect of negative regulation of GSK-3β. These results indicated that enhancing autophagy may be a key downstream effect of GSK-3β inhibition in the alleviation of cisplatin-induced ototoxicity both in vivo and in vitro. Topics: Animals; Auditory Fatigue; Autophagy; Cell Line; Cisplatin; Disease Models, Animal; Down-Regulation; Ear Diseases; Evoked Potentials, Auditory, Brain Stem; Glycogen Synthase Kinase 3 beta; Hair Cells, Auditory; Lithium Chloride; Male; Rats, Sprague-Dawley; Signal Transduction | 2019 |
Monocytes as Carriers of Magnetic Nanoparticles for Tracking Inflammation in the Epileptic Rat Brain.
Inflammation is a hallmark of epileptogenic brain tissue. Previously, we have shown that inflammation in epilepsy can be delineated using systemically-injected fluorescent and magnetite- laden nanoparticles. Suggested mechanisms included distribution of free nanoparticles across a compromised blood-brain barrier or their transfer by monocytes that infiltrate the epileptic brain.. In the current study, we evaluated monocytes as vehicles that deliver nanoparticles into the epileptic brain. We also assessed the effect of epilepsy on the systemic distribution of nanoparticleloaded monocytes.. The in vitro uptake of 300-nm nanoparticles labeled with magnetite and BODIPY (for optical imaging) was evaluated using rat monocytes and fluorescence detection. For in vivo studies we used the rat lithium-pilocarpine model of temporal lobe epilepsy. In vivo nanoparticle distribution was evaluated using immunohistochemistry.. 89% of nanoparticle loading into rat monocytes was accomplished within 8 hours, enabling overnight nanoparticle loading ex vivo. The dose-normalized distribution of nanoparticle-loaded monocytes into the hippocampal CA1 and dentate gyrus of rats with spontaneous seizures was 176-fold and 380-fold higher compared to the free nanoparticles (p<0.05). Seizures were associated with greater nanoparticle accumulation within the liver and the spleen (p<0.05).. Nanoparticle-loaded monocytes are attracted to epileptogenic brain tissue and may be used for labeling or targeting it, while significantly reducing the systemic dose of potentially toxic compounds. The effect of seizures on monocyte biodistribution should be further explored to better understand the systemic effects of epilepsy. Topics: Animals; Boron Compounds; Disease Models, Animal; Drug Delivery Systems; Epilepsy, Temporal Lobe; Fluorescent Dyes; Hippocampus; Inflammation; Kidney; Lithium Chloride; Liver; Magnetite Nanoparticles; Male; Monocytes; Pilocarpine; Rats, Wistar; Spleen | 2019 |
Anti-inflammatory treatment with a soluble epoxide hydrolase inhibitor attenuates seizures and epilepsy-associated depression in the LiCl-pilocarpine post-status epilepticus rat model.
This study aimed to investigate whether 1-trifluoromethoxyphenyl-3-(1-propionylpiperidin-4-yl) urea (TPPU), a soluble epoxide hydrolase inhibitor with anti-inflammatory effects, could alleviate spontaneous recurrent seizures (SRS) and epilepsy-associated depressive behaviours in the lithium chloride (LiCl)-pilocarpine-induced post-status epilepticus (SE) rat model.. The rats were intraperitoneally (IP) injected with LiCl (127 mg/kg) and pilocarpine (40 mg/kg) to induce SE. A video surveillance system was used to monitor SRS in the post-SE model for 6 weeks (from the onset of the 2nd week to the end of the 7th week after SE induction). TPPU (0.1 mg/kg/d) was intragastrically given for 4 weeks from the 21st day after SE induction in the SRS + 0.1 TPPU group. The SRS + PEG 400 group was given the vehicle (40% polyethylene glycol 400) instead, and the control group was given LiCl and PEG 400 but not pilocarpine. The sucrose preference test (SPT) and forced swim test (FST) were conducted to evaluate the depression-like behaviours of rats. Immunofluorescent staining, enzyme-linked immunosorbent assay, and western blot analysis were performed to measure astrocytic and microglial gliosis, neuronal loss, and levels of soluble epoxide hydrolase (sEH), cytokines [tumour necrosis factor alpha (TNF-α), interleukin (IL)-1β, and IL-6], and cyclic adenosine monophosphate (cAMP)-response element binding protein (CREB).. The frequency of SRS was significantly decreased at 6 weeks and 7 weeks after SE induction in the 0.1TPP U group compared with the SRS + PEG 400 group. The immobility time (IMT) evaluated by FST was significantly decreased, whereas the climbing time (CMT) was increased, and the sucrose preference rate (SPR) evaluated by SPT was in an increasing trend. The levels of sEH, TNF-α, IL-1β, and IL-6 in the hippocampus (Hip) and prefrontal cortex (PFC) were all significantly increased in the SRS + PEG 400 group compared with the control group; neuronal loss, astrogliosis, and microglial activation were also observed. The astrocytic and microglial activation and levels of the pro-inflammatory cytokines in the Hip and PFC were significantly attenuated in the TPPU group compared with the SRS + PEG 400 group; moreover, neuronal loss and the decreased CREB expression were significantly alleviated as well.. TPPU treatment after SE attenuates SRS and epilepsy-associated depressive behaviours in the LiCl-pilocarpine induced post-SE rat model, and it also exerts anti-inflammatory effects in the brain. Our findings suggest a new therapeutic approach for epilepsy and its comorbidities, especially depression. Topics: Animals; Astrocytes; Brain; Depression; Depressive Disorder; Disease Models, Animal; Epilepsy; Epoxide Hydrolases; Hippocampus; Lithium Chloride; Male; Microglia; Neurons; Phenylurea Compounds; Pilocarpine; Piperidines; Rats; Rats, Sprague-Dawley; Seizures; Status Epilepticus; Tumor Necrosis Factor-alpha | 2019 |
The anticonvulsant activity and cerebral protection of chronic lithium chloride via NMDA receptor/nitric oxide and phospho-ERK.
The underlying mechanisms for the neuroprotective effects of lithium chloride in neurodegenerative diseases such as seizures remain unknown. In present study the downstream signaling pathway of phospho-ERK/NMDA receptors/nitric oxide has been studied. For this purpose, acute and chronic effect of lithium in seizure animal model and the interaction of NMDA receptor antagonist (MK-801) and neuronal nitric oxide synthase (nNOS) inhibitor (7-NI) with these neuroprotection has been studied. Acute lithium administration showed pro-convulsive properties in pentylenetetrazole (PTZ)-induced seizure model while chronic treatment increased the seizure threshold significantly. The serum level of lithium in treated mice were 0.48 mEq/L corresponding the therapeutic range. Administration of 7-NI (30mg/kg, i.p.) and MK-801 (0.001mg/kg, i.p.) had no effect on seizure threshold, while co-administration of them before the sub-effective dose of lithium (4mg/kg, i.p.) increased the anticonvulsant effect of lithium significantly. Furthermore, acute injection of MK-801 (0.05mg/kg) or 7-NI (60mg/kg) and co-administration of them significantly suppressed the anticonvulsant effect of effective dose of lithium (10mg/kg). This data demonstrated involvement of NMDA receptors/nitric oxide pathway in anticonvulsant effect of lithium. In cerebellar granule neurons (CGNs) culture studies on glutamate excitotoxicity western blot analysis, nitrite assay by Griess reaction, cell viability and microscopic morphology evaluation has been carried out to find the role of NMDA receptor/nitric oxide and phospho-ERK signaling in lithium neuroprotection. Using MTT assay and morphologic examinations, chronic lithium treatment showed protective effects against glutamate toxicity in primary cerebellar culture neurons. The level of nitric oxide was significantly reduced in co-administration of lithium and glutamate while glutamate significantly increased levels of nitric oxide. The involvement of NMDA receptors/nitric oxide and phospho-ERK pathway in the effects of lithium on cerebellar neurons has been shown. Inhibition of ERK signaling may be reconsidered as a pharmacological approach for seizure control. Topics: Animals; Anticonvulsants; Cells, Cultured; Cerebellum; Cerebral Cortex; Disease Models, Animal; Dizocilpine Maleate; Excitatory Amino Acid Antagonists; Glutamic Acid; Lithium Chloride; Male; MAP Kinase Signaling System; Mice; Neurons; Neuroprotective Agents; Nitric Oxide; Nitric Oxide Synthase Type I; Pentylenetetrazole; Phosphorylation; Receptors, N-Methyl-D-Aspartate; Seizures | 2018 |
Developmental Ethanol-Induced Sleep Fragmentation, Behavioral Hyperactivity, Cognitive Impairment and Parvalbumin Cell Loss are Prevented by Lithium Co-treatment.
Developmental ethanol exposure is a well-known cause of lifelong cognitive deficits, behavioral hyperactivity, emotional dysregulation, and more. In healthy adults, sleep is thought to have a critical involvement in each of these processes. Our previous work has demonstrated that some aspects of cognitive impairment in adult mice exposed at postnatal day 7 (P7) to ethanol (EtOH) correlate with slow-wave sleep (SWS) fragmentation (Wilson et al., 2016). We and others have also previously demonstrated that co-treatment with LiCl on the day of EtOH exposure prevents many of the anatomical and physiological impairments observed in adults. Here we explored cognitive function, diurnal rhythms (activity, temperature), SWS, and parvalbumin (PV) and perineuronal net (PNN)-positive cell densities in adult mice that had received a single day of EtOH exposure on P7 and saline-treated littermate controls. Half of the animals also received a LiCl injection on P7. The results suggest that developmental EtOH resulted in adult behavioral hyperactivity, cognitive impairment, and reduced SWS compared to saline controls. Both of these effects were reduced by LiCl treatment on the day of EtOH exposure. Finally, developmental EtOH resulted in decreased PV/PNN-expressing cells in retrosplenial (RS) cortex and dorsal CA3 hippocampus at P90. As with sleep and behavioral activity, LiCl treatment reduced this decrease in PV expression. Together, these results further clarify the long-lasting effects of developmental EtOH on adult behavior, physiology, and anatomy. Furthermore, they demonstrate the neuroprotective effects of LiCl co-treatment on this wide range of developmental EtOH's long-lasting consequences. Topics: Animals; Animals, Newborn; Cerebral Cortex; Cognition; Cognitive Dysfunction; Disease Models, Animal; Female; Fetal Alcohol Spectrum Disorders; Hyperkinesis; Lithium Chloride; Male; Mice, Inbred C57BL; Neuroprotective Agents; Nootropic Agents; Parvalbumins; Sleep; Sleep Deprivation | 2018 |
Does status epilepticus modify the effect of ifenprodil on cortical epileptic afterdischarges in immature rats?
Ifenprodil as a specific antagonist of NMDA receptors containing a dominant NR2B subunit exhibits age-dependent anticonvulsant action. Possible changes of this action due to status epilepticus (SE) elicited at early stage of development were studied using cortical epileptic afterdischarges (ADs) as a model.. Lithium-pilocarpine SE was induced at postnatal day 12 and effects of ifenprodil were studied 3, 6, 9, and 13 days after SE in rat pups with implanted epidural electrodes. Controls (LiPAR) received saline instead of pilocarpine. ADs were elicited by low frequency stimulation of sensorimotor cortex. Intensity of stimulation current increased in 18 steps from 0.2 to 15 mA. Ifenprodil (20 mg/kg) was administered intraperitoneally (ip) after the stimulation with 3.5-mA current. Threshold for four different phenomena as well as duration of ADs were evaluated.. The threshold for the transition into the limbic type of ADs was higher in 15-day-old SE rats than in LiPAR controls. Opposite difference was found in 18-day-old animals, older rats did not exhibit any difference. Isolated significant changes in total duration of ADs were found after high stimulation intensities. These changes appeared in 18-day-old rats where ADs were shorter in SE than in control LiPAR rats.. Changes in ifenprodil action were found only in the first week after SE but not in the second week. Interpretation of the results is complicated by failure of significant differences between SE and LiPAR rats probably due to a high dose of paraldehyde. Topics: Age Factors; Animals; Animals, Newborn; Anticonvulsants; Brain Waves; Cerebral Cortex; Disease Models, Animal; Electric Stimulation; Excitatory Amino Acid Antagonists; Lithium Chloride; Male; Pilocarpine; Piperidines; Rats, Wistar; Receptors, N-Methyl-D-Aspartate; Status Epilepticus | 2018 |
Tamoxifen attenuates development of lithium-induced nephrogenic diabetes insipidus in rats.
Lithium is widely used in treatment of bipolar affective disorders but often causes nephrogenic diabetes insipidus (NDI), a disorder characterized by severe urinary-concentrating defects. Lithium-induced NDI is caused by lithium uptake by collecting duct principal cells and altered expression of aquaporin-2 (AQP2), which are essential for water reabsorption of tubular fluid in the collecting duct. Sex hormones have previously been shown to affect the regulation of AQP2, so we tested whether tamoxifen (TAM), a selective estrogen receptor modulator, would attenuate lithium-induced alterations on renal water homeostasis. Rats were treated for 14 days with lithium, and TAM treatment was initiated 1 wk after onset of lithium administration. Lithium treatment resulted in severe polyuria and reduced AQP2 expression, which were ameliorated by TAM. Consistent with this, TAM attenuated downregulation of AQP2 and increased phosphorylation of the cAMP-responsive element-binding protein, which induced AQP2 expression in freshly isolated inner-medullary collecting duct suspension prepared from lithium-treated rats. In conclusion, TAM attenuated polyuria dose dependently and impaired urine concentration and downregulation of AQP2 protein expression in rats with lithium-induced NDI. These findings suggest that TAM is likely to be a novel therapeutic option for lithium-induced NDI. Topics: Animals; Aquaporin 2; CREB-Binding Protein; Diabetes Insipidus, Nephrogenic; Disease Models, Animal; Dose-Response Relationship, Drug; Estrogen Receptor alpha; Estrogen Receptor beta; Hypoglycemic Agents; Kidney Concentrating Ability; Kidney Tubules, Collecting; Lithium Chloride; Male; Phosphorylation; Polyuria; Rats, Sprague-Dawley; Tamoxifen; Time Factors | 2018 |
Status epilepticus: Role for etiology in determining response to benzodiazepines.
Clinical factors contributing to benzodiazepine failure in treating status epilepticus (SE) include suboptimal dosing and seizure duration. As many benzodiazepine-refractory episodes of SE arise from acute etiologies, we sought to determine whether etiology impacts SE treatment.. The potency of diazepam to terminate SE induced by lithium-pilocarpine (LiPilo-SE) or kainic acid (KA-SE) in 3-week-old rats was studied by video-electroencephalography. Synaptic γ-aminobutyric acid type A receptor (GABAR)-mediated currents were recorded from dentate granule cells using voltage-clamp electrophysiology. Surface expression of γ2 subunit-containing GABARs and Kv4.2 potassium channels in hippocampal slices was determined using a biotinylation assay. Expression of phosphorylated forms of β2/3 and γ2 subunits was determined using phosphospecific antibodies and Western blotting.. Diazepam failed to terminate late SE in LiPilo-SE animals but was successful in terminating KA-SE of 1- and 3-hour duration. One hour after SE onset, GABAR-mediated synaptic inhibition and γ2 subunit-containing GABAR surface expression were reduced in LiPilo-SE animals. These were unchanged in KA-SE animals at 1 and 3 hours. Phosphorylation of γ2 subunit residue S327 was unchanged in both models, although GABAR β3 subunit S408/409 residues were dephosphorylated in the LiPilo-SE animals. Kv4.2 potassium channel surface expression was increased in LiPilo-SE animals but reduced in KA-SE animals.. SE-model-dependent differences support a novel hypothesis that the development of benzodiazepine pharmacoresistance may be etiologically predetermined. Further studies are required to investigate the mechanisms that underlie such etiological differences during SE and whether etiology-dependent protocols for the treatment of SE need to be developed. Ann Neurol 2018;83:830-841. Topics: Animals; Benzodiazepines; Brain Waves; Convulsants; Disease Models, Animal; Electroencephalography; Gene Expression Regulation; Hippocampus; Kainic Acid; Lipoproteins; Lithium Chloride; Male; Phosphorylation; Pilocarpine; Protein Transport; Rats; Rats, Sprague-Dawley; Receptors, GABA-A; Shal Potassium Channels; Statistics, Nonparametric; Status Epilepticus; Time Factors | 2018 |
Mefloquine targets β-catenin pathway and thus can play a role in the treatment of liver cancer.
The current study was designed and performed to investigate the effect of mefloquine on the proliferation and tumor formation potential of liver cancer stem cells. CD133 + HepG2 cells were identified using MACS and showed markedly higher tumor formation potential compared to the parental cells. The secondary tumors formed by CD133 + cells were markedly large in size and more in number compared to the parental cells. Mefloquine treatment of CD133 + HepG2 cells inhibited the proliferation selectively in concentration based manner. The rate of proliferation was inhibited to 82 and 12% in parental and CD133 + sphere forming cells, respectively on treatment with 10 μM concentration of mefloquine. The number of secondary tumors formed by primary tumors was decreased significantly on treatment with 10 μM mefloquine concentration. Treatment of the liver cancer stem cells with mefloquine markedly decreased the potential to undergo self-renewal at 10 μM concentration after 48 h. The results from western blot analysis showed significantly higher expression of cancer stem cell molecules β-catenin and cyclin D1 in LCSCs. Treatment of the LCSCs with various concentrations of mefloquine reduced the expression levels of β-catenin and cyclin D1. Administration of the CD133 + cell tumor xenografts in the mice led to the formation of large sized tumors in the control group. However, the tumor growth was inhibited significantly in the mice on treatment with 10 mg/kg doses of mefloquine after day 21. The tumor weight was significantly lower in the animals of mefloquine treatment group compared to the control group. Thus, mefloquine treatment inhibits self-renewal and proliferation potential of cells through targeting β-catenin pathway. Topics: AC133 Antigen; Animals; beta Catenin; Carcinoma, Hepatocellular; Cell Proliferation; Cell Survival; Cyclin D1; Disease Models, Animal; Drug Combinations; Hep G2 Cells; Humans; Lithium Chloride; Liver Neoplasms; Male; Mefloquine; Mice; Mice, Inbred BALB C; Neoplastic Stem Cells; Transplantation, Heterologous | 2018 |
Different behavioral and pathological changes between epilepsy-associated depression and primary depression models.
Comorbid depression is common in patients with epilepsy. However, the epilepsy-associated depression is generally atypical and has not been fully recognized by neurologists. This study aimed to compare the behavioral and pathological changes between the chronic lithium chloride-pilocarpine rat epilepsy model (Licl-pilocarpine model) and the Chronic Unpredictable Mild Stress rat depression model (CUMS model), to evaluate for differences between epilepsy-associated depression and primary depression.. The Licl-pilocarpine model and the CUMS model were established respectively and simultaneously. Spontaneous seizures were recorded by video monitoring. Forced swim test (FST) and sucrose consumption test (SCT) were performed to test depressive behaviors. Immobility time (IMT) and climbing time (CMT) in FST, sucrose preference rate (SPR) in SCT, and weight gain rate (WGR) were adopted to represent severity of depressive behaviors in rats. Immunofluorescent staining was conducted to measure expressions of neuronal specific nuclear protein (NeuN), glial fibrillary acidic protein (GFAP), and cluster of differentiation molecule 11b (CD11b) in the hippocampus of Licl-pilocarpine model, CUMS model, and Control group.. Significantly, more prolonged IMT was observed in both the Licl-pilocarpine model (p<0.05) and the CUMS model (p<0.01) than Control group. But decreased WGR was only seen in the CUMS model. The percentage of rats with CMT greater than 100s was significantly higher in the Licl-pilocarpine model than the CUMS model (p<0.05). Increased CMT was observed in the Licl-pilocarpine model with mild depression subgroup (EMD, IMT≤100s) even compared with the Control group. Neuronal loss was both found in the Licl-pilocarpine model and the CUMS model when comparing with the Control group (p<0.05). However, the number of GFAP and CD11b staining cells was both greater in the Licl-pilocarpine model than the CUMS model and the Control group (p<0.05).. There were some different depressive behavioral and hippocampal pathological changes between the Licl-pilocarpine and the CUMS models except for some common features. Gliosis and microglial activation might be more involved in the pathophysiology of epilepsy-associated depression than primary depression. Topics: Animals; Depression; Disease Models, Animal; Epilepsy; Hippocampus; Lithium Chloride; Male; Pilocarpine; Rats; Rats, Sprague-Dawley; Stress, Psychological; Swimming | 2018 |
Differential expression of synaptic vesicle protein 2A after status epilepticus and during epilepsy in a lithium-pilocarpine model.
Synaptic vesicle protein 2A (SV2A) has become an attractive target of investigation because of its role in the pathophysiology of epilepsy; SV2A is expressed ubiquitously throughout the brain in all nerve terminals independently of their neurotransmitter content and plays an important but poorly defined role in neurotransmission. Previous studies have shown that modifications in the SV2A protein expression could be a direct consequence of disease severity. Furthermore, these SV2A modifications may depend on specific changes in the nerve tissue following the induction of epilepsy and might be present in both excitatory and inhibitory terminals. Thus, we evaluated SV2A protein expression throughout the hippocampi of lithium-pilocarpine rats after status epilepticus (SE) and during early and late epilepsy. In addition, we determined the γ-aminobutyric acid (GABA)ergic or glutamatergic nature associated with SV2A modifications. Wistar rats were treated with lithium-pilocarpine to induce SE and subsequently were shown to present spontaneous recurrent seizures (SRS). Later, we conducted an exhaustive semi-quantitative analysis of SV2A optical density (OD) throughout the hippocampus by immunohistochemistry. Levels of the SV2A protein were substantially increased in layers formed by principal neurons after SE, mainly because of GABAergic activity. No changes were observed in the early stage of epilepsy. In the late stage of epilepsy, there were minor changes in SV2A OD compared with the robust modifications of SE; however, SV2A protein expression generally showed an increment reaching significant differences in two dendritic layers and hilus, without clear modifications of GABAergic or glutamatergic systems. Our results suggest that the SV2A variations may depend on several factors, such as neuronal activity, and might appear in both excitatory and inhibitory systems depending on the epilepsy stage. Topics: Animals; Disease Models, Animal; Gene Expression; Hippocampus; Lithium Chloride; Male; Membrane Glycoproteins; Nerve Tissue Proteins; Neurons; Pilocarpine; Rats; Rats, Wistar; Status Epilepticus | 2018 |
Effect of renal ischemia on urinary excretion of lithium in rats.
Lithium, administered to patients with bipolar disorders, is mainly excreted in the urine, and tubular reabsorption is involved. This study characterized the renal excretion of lithium in rats subjected to renal ischemia for 60 min or 90 min. After intravenous injection of lithium chloride at 25 mg/kg, the pharmacokinetic parameters of lithium were determined. In sham-operated rats, the renal clearance of lithium was calculated to be 1.49 ml/min/kg, and its ratio to creatinine clearance (fractional excretion) was 43.4%. Renal ischemia inhibited the renal excretion of lithium, and did not affect its fractional excretion. The urinary pH of rats with renal ischemia for 90 min was significantly higher than those of the other groups, and the linear regression with the fractional excretion of lithium in rats with renal ischemia showed a moderate correlation (r = 0.650, p = 0.00193). This study demonstrated the effect of renal ischemia on the renal excretion of lithium in rats. It was suggested that not only glomerular filtration but also the reabsorption of lithium was impaired by renal ischemia. Topics: Animals; Antimanic Agents; Disease Models, Animal; Hydrogen-Ion Concentration; Injections, Intravenous; Ischemia; Kidney; Linear Models; Lithium Chloride; Male; Rats; Rats, Wistar; Time Factors | 2018 |
Inhibiting Effect of Lithium Chloride on Endotoxin-induced Uveitis in Rats.
To evaluate the anti-inflammatory effect of lithium chloride in endotoxin-induced uveitis.. A total of 200 Wistar rats were randomly divided into four groups: a control group; EIU group; LiCl-treated control group; and LiCl-treated lipopolysaccharide group. Clinical score, slit-lamp photography, hematoxylin and eosin (H&E) staining were used to determine the degree of inflammatory reaction. Level of glycogen synthase kinase3-beta and nuclear factor-kappa B p65 in iris-ciliary body was examined by western blot and RT-PCR. Cytokines in aqueous humor were detected by ELISA.. Pretreatment with LiCl produced an anti-inflammatory effect during endotoxin-induced uveitis (EIU). With LiCl treatment, the level of P-GSK3-β in iris-ciliary body was upregulated and the expression of NF-κB p65 was significantly suppressed during EIU.. LiCl pretreatment can suppress intraocular inflammatory responses in EIU rats. Mechanistically, this anti-inflammatory effect may be related to the inhibitory phosphorylation of GSK3-β. Topics: Adjuvants, Immunologic; Animals; Aqueous Humor; Blotting, Western; Carrier Proteins; Ciliary Body; Disease Models, Animal; Enzyme-Linked Immunosorbent Assay; Gene Expression Regulation; Intracellular Signaling Peptides and Proteins; Iris; Lithium Chloride; Male; Rats; Rats, Wistar; Real-Time Polymerase Chain Reaction; Transcription Factor RelA; Tumor Necrosis Factor-alpha; Uveitis | 2018 |
NMDAR-independent hippocampal long-term depression impairment after status epilepticus in a lithium-pilocarpine model of temporal lobe epilepsy.
Temporal lobe epilepsy is usually associated with cognitive decline and memory deficits. Despite numerous existing studies on various animal models, the mechanisms of these deficits remain largely unclear. A specific form of long-term synaptic efficacy changes-long-term depression (LTD)-is thought to play an important role in memory formation and learning. However, extremely little is known about the possible alteration of LTD induction and dynamics after a status epilepticus (SE). In this work, we investigated the acute and delayed effects of lithium-pilocarpine-induced SE on NMDAR-dependent and NMDAR-independent hippocampal LTD in vitro. We found that SE affected the NMDAR-dependent and NMDAR-independent forms of LTD in different manners. The NMDAR-dependent form of LTD was almost intact 3 days after SE, but it switched from a predominantly presynaptic to a more postsynaptic locus of expression. In contrast, the NMDAR-independent LTD in the hippocampal Schaffer collaterals-CA1 synapses was fully abolished 3 days after SE. Our results emphasize the role of non-NMDA-dependent synaptic plasticity changes in the processes of epileptogenesis and the potential for therapy development. Topics: 2-Amino-5-phosphonovalerate; Animals; CA1 Region, Hippocampal; CA3 Region, Hippocampal; Disease Models, Animal; Epilepsy, Temporal Lobe; Excitatory Amino Acid Antagonists; Excitatory Postsynaptic Potentials; Lithium Chloride; Long-Term Synaptic Depression; Male; Pilocarpine; Random Allocation; Rats, Wistar; Receptors, N-Methyl-D-Aspartate; Status Epilepticus; Synapses; Time Factors; Tissue Culture Techniques | 2017 |
Involvement of microRNA-146a in the Inflammatory Response of S tatus Epilepticus Rats.
Status epilepticus (SE), is characterized by high mortality and morbidity, which can cause neuronal injury, neuronal death and alteration of neuronal networks, Recently, inflammation was shown to play a significant role in SE pathogenesis. And miRNA-146a has been shown to be involved in inflammation and to inhibit inflammatory cytokines through NF-κB pathway. In our study, we investigated the relationship between inflammation and miR-146a expression.. The SE rat model was induced by lithium-pilocarpine. Hematoxylin and eosin staining (H&E) was performed to observe the histopathology of the rat hippocampus. The expression of COX-2, TNF-α, IL-6 and IL-1β were respectively measured by Western blot and Bio-Plex ProTM Assays. The miR-146a expression in hippocampus tissue was measured by Quantitative real-time PCR.. microRNA-146a was highly expressed in the hippocampus of SE rats coupled with increased level of inflammatory cytokines than the normal group. And TQ can attune the expression of inflammatory cytokines, meanwhile, miR-146a was lower in TQ group. The expression of miRNA-146a were positively correlated with the level of inflammatory reaction.. TQ may alleviate the inflammatory reaction by inhibiting the NF-κB signaling pathway. Our study shows that miRNA-146a was involved in the inflammatory response and indicated inflammation severity in SE rats. Therefore, miRNA-146a may serve as a potential biomarker or a therapeutic target in SE. Topics: Animals; Anticonvulsants; Benzoquinones; Cytokines; Disease Models, Animal; Gene Expression Regulation; Hippocampus; Inflammation; Lithium Chloride; Male; MicroRNAs; Muscarinic Agonists; NF-kappa B; Pilocarpine; Rats; Rats, Sprague-Dawley; Status Epilepticus | 2017 |
Lithium Chloride Facilitates Autophagy Following Spinal Cord Injury via ERK-dependent Pathway.
Spinal cord injury (SCI) is one major cause of death and results in long-term disability even in the most productive periods of human lives with few efficacious drugs. Autophagy is a potential therapeutic target for SCI. In the present study, we examined the role of lithium in functional recovery in the rat model of SCI and explored the related mechanism. Locomotion tests were employed to assess the functional recovery after SCI, Western blotting and RT-PCT to determine the level of p-ERK and LC3-II as well as p62, immunofluorescence imaging to localize LC3 and p62. Here, we found that both the expression of LC3-II and p62 were increased after SCI. However, lithium chloride enhanced the level of LC3-II while abrogated the abundance of p62. Furthermore, lithium treatment facilitated ERK activation in vivo, and inhibition of MEK/ERK signaling pathway suppressed lithium-evoked autophagy flux. Taken together, our results illustrated that lithium facilitated functional recovery by enhancing autophagy flux. Topics: Animals; Apoptosis; Autophagy; Disease Models, Animal; Lithium Chloride; Male; MAP Kinase Signaling System; Microtubule-Associated Proteins; Neuroprotective Agents; Rats, Sprague-Dawley; Recovery of Function; Spinal Cord; Spinal Cord Injuries | 2017 |
Inherent vulnerabilities in monoaminergic pathways predict the emergence of depressive impairments in an animal model of chronic epilepsy.
The objective was to determine whether the depression comorbid with epilepsy could be predicted based on inherent premorbid patterns of monoaminergic transmission. In male Wistar rats, despair-like and anhedonia-like behaviors were examined using forced swimming and taste preference tests, respectively. Serotonergic raphe nucleus (RN)-prefrontal cortex (PFC) and dopaminergic ventral tegmental area (VTA)-nucleus accumbens (NAcc) pathways were interrogated by fast scan cyclic voltammetry (FSCV). The assays were performed before and 2 months after pilocarpine status epilepticus. In a subset of naive rats, FSCV, coupled with the intensity-dependent stimulation paradigm, detected specific deviations in each pathway (six rats for RN-PFC and seven rats for VTA-NAcc, with overlap in two, of 19 total subjects) in the absence of behavioral impairments. During epilepsy, animals with preexisting deviations in RN-PFC invariably developed despair, and rats with deviations in VTA-NAcc developed anhedonia. Serotonergic and dopaminergic pathways, respectively, showed signs of explicit deterioration. We suggest that epilepsy triggers decompensations in the already vulnerable depression-relevant neuronal circuits, which culminate in depression. The established connection between the identified specific signatures in monoamine transmission in naive rats and specific symptoms of epilepsy-associated depression may help in understanding causes of comorbidity and in developing its early biomarkers. Topics: Animals; Anticonvulsants; Biogenic Monoamines; Convulsants; Depression; Disease Models, Animal; Epilepsy; Food Preferences; Lithium Chloride; Male; Neural Pathways; Pilocarpine; Rats; Rats, Wistar; Swimming | 2017 |
Lithium-induced NDI: acetazolamide reduces polyuria but does not improve urine concentrating ability.
Lithium is the mainstay treatment for patients with bipolar disorder, but it generally causes nephrogenic diabetes insipidus (NDI), a disorder in which the renal urine concentrating ability has become vasopressin insensitive. Li-NDI is caused by lithium uptake by collecting duct principal cells and downregulation of aquaporin-2 (AQP2) water channels, which are essential for water uptake from tubular urine. Recently, we found that the prophylactic administration of acetazolamide to mice effectively attenuated Li-NDI. To evaluate whether acetazolamide might benefit lithium-treated patients, we administered acetazolamide to mice with established Li-NDI and six patients with a lithium-induced urinary concentrating defect. In mice, acetazolamide partially reversed lithium-induced polyuria and increased urine osmolality, which, however, did not coincide with increased AQP2 abundances. In patients, acetazolamide led to the withdrawal of two patients from the study due to side effects. In the four remaining patients acetazolamide did not lead to clinically relevant changes in maximal urine osmolality. Urine output was also not affected, although none of these patients demonstrated overt lithium-induced polyuria. In three out of four patients, acetazolamide treatment increased serum creatinine levels, indicating a decreased glomerular filtration rate (GFR). Strikingly, these three patients also showed a decrease in systemic blood pressure. All together, our data reveal that acetazolamide does not improve the urinary concentrating defect caused by lithium, but it lowers the GFR, likely explaining the reduced urine output in our mice and in a recently reported patient with lithium-induced polyuria. The reduced GFR in patients prone to chronic kidney disease development, however, warrants against application of acetazolamide in Li-NDI patients without long-term (pre)clinical studies. Topics: Acetazolamide; Aged; Animals; Aquaporin 2; Blood Pressure; Diabetes Insipidus, Nephrogenic; Disease Models, Animal; Diuretics; Female; Glomerular Filtration Rate; Humans; Kidney; Kidney Concentrating Ability; Lithium Chloride; Male; Mice, Inbred C57BL; Middle Aged; Netherlands; New Zealand; Osmolar Concentration; Pilot Projects; Polyuria; Prospective Studies; Time Factors; Treatment Outcome | 2017 |
Recovery of spinal cord injury following electroacupuncture in rats through enhancement of Wnt/β-catenin signaling.
Electroacupuncture (EA) has been demonstrated to promote the functional recovery of neurons following spinal cord injury (SCI); however, the mechanisms underlying its effects have yet to be elucidated. The Wnt/β-catenin signaling pathway has been implicated in the regulation of the balance between growth, proliferation and differentiation of neural precursor cells. The present study aimed to investigate the effects of EA therapy on Wnt/β‑catenin‑regulated gene expression and neuronal recovery in rats with SCI. The Allen method was used to establish SCI in rats, and alterations in Wnt1 and Nestin mRNA and protein expression levels in response to SCI were determined on days 1, 3, 7 and 14 post‑injury using reverse transcription‑quantitative polymerase chain reaction and western blot analysis. To evaluate the effects of EA treatment on SCI, the following four treatment groups were employed: SCI, SCI + EA, SCI + lithium chloride (LiCl) and SCI + LiCl + EA. The protein expression levels of Wnt1, Nestin and nuclear β‑catenin were evaluated on day 3 post‑treatment, and neuronal nuclear antigen (NeuN) protein expression levels were evaluated on day 21 post‑treatment using western blot analysis. The Basso, Beattie and Bresnahan scoring method was used to evaluate spinal cord recovery on day 28 post‑treatment across the four treatment groups. EA therapy at the Dazhui and Mingmen acupuncture points significantly increased the expression levels of Wnt1, Nestin, β‑catenin and NeuN, thus suggesting that EA therapy may promote spinal cord recovery following injury. The underlying mechanism was demonstrated to involve enhanced Wnt/β‑catenin signaling, which may promote the proliferation and differentiation of neural stem cells. However, further studies are required to elucidate the detailed effects and underlying molecular mechanisms of EA therapy on SCI. Topics: Animals; Antigens, Nuclear; beta Catenin; Cell Differentiation; Cell Proliferation; Disease Models, Animal; Electroacupuncture; Lithium Chloride; Male; Nerve Tissue Proteins; Nestin; Neural Stem Cells; Rats; Rats, Sprague-Dawley; Recovery of Function; Spinal Cord Injuries; Wnt Signaling Pathway; Wnt1 Protein | 2017 |
Neuroprotective effects of vitamin D alone or in combination with lamotrigine against lithium-pilocarpine model of status epilepticus in rats.
Status epilepticus (SE) is considered one of the major serious forms of epilepsy with high mortality rate. Since the currently available antiepileptic drugs have low efficacy and high adverse effects, new more efficient and safe therapies are critically needed. There is increasing evidence supporting dietary and alternative therapies for epilepsy, including the ketogenic diet, modified Atkins diet, and omega-3 fatty acids. Recent studies have shown significant prophylactic and therapeutic potential of vitamin D (vit-D) use in many neurological disorders. Therefore, in the present study, the neuroprotective effects and mechanisms of vit-D alone or in combination with lamotrigine have been evaluated in the lithium-pilocarpine model of SE in rats. Rats were divided into five groups: normal group, SE group, lamotrigine (25 mg/kg/day) pretreated group, vit-D (1.5 mcg/kg/day) pretreated group, and group pretreated with vit-D and lamotrigine for 2 weeks. At the end of treatment, SE was induced by single intraperitoneal injection of LiCl (127 mg/kg), followed 24 h later by pilocarpine (30 mg/kg). Seizures' latency, cognitive performance in Morris water maze, brain oxidative stress biomarkers (glutathione, lipid peroxides, and nitric oxide), brain neurochemistry (γ-aminobutyric acid and glutamate), and brain histopathology have been evaluated. Vit-D prevented pilocarpine-induced behavioral impairments and oxidative stress in the brain; these results were improved in combination with lamotrigine. Vit-D has a promising antiepileptic, neuroprotective, and antioxidant effects. It can be provided to patients as a supportive treatment besides antiepileptic drugs. However, clinical trials are needed to establish its efficacy and safety. Topics: Animals; Anticonvulsants; Antioxidants; Disease Models, Animal; Drug Therapy, Combination; Lamotrigine; Lithium Chloride; Male; Neuroprotective Agents; Pilocarpine; Rats; Rats, Wistar; Status Epilepticus; Treatment Outcome; Triazines | 2017 |
Dynamic regulation effect of long non-coding RNA-UCA1 on NF-kB in hippocampus of epilepsy rats.
We aimed to discuss the mechanism of occurrence and progression of epilepsy through analyzing the expression changes of UCA1 and NF-Kb in temporal hippocampus and UCA1 in peripheral blood in rats with epilepsy induced by lithium chloride-pilocarpine.. The lithium chloride-pilocarpine-induced epilepsy rat model was established; 1, 7, 14, 30, and 60 d after status epilepticus were selected as the time points of research. The expression levels of UCA1 and NF-kB in the hippocampus of rats and UCA1 in peripheral blood were detected and analyzed using quantitative Real-time PCR (qRT-PCR). The differences and correlations between expression levels of UCA1 and NF-kB at each time point of research in experimental group and control group were analyzed statistically.. Results showed that mRNA expression levels of UCA1 and NF-kB in brain tissues in experimental group were higher than those in control group at each time point. The change trend of expression levels of UCA1 and NF-kB with time was consistent. The expression level of UCA1 in peripheral blood in experimental group at each time point was higher than that in control group, and mRNA expression level of UCA1 in peripheral blood in experimental group was positively correlated with that in brain tissue.. The expressions of UCA1 and NF-Kb are in the dynamic change in the formation of epilepsy, suggesting that UCA1 may participate in the pathogenesis of epilepsy, so as to provide a potentially feasible new direction for guiding the clinical diagnosis and treatment of epilepsy. Topics: Animals; Behavior, Animal; Disease Models, Animal; Disease Progression; Epilepsy; Gene Expression Regulation; Hippocampus; Lithium Chloride; Male; NF-kappa B; Pilocarpine; Rats; Rats, Sprague-Dawley; RNA, Long Noncoding; RNA, Messenger | 2017 |
Fluoxetine ameliorates cartilage degradation in osteoarthritis by inhibiting Wnt/β-catenin signaling.
Abnormal activation of the Wnt/β-catenin signaling is implicated in the osteoarthritis (OA) pathology. We searched for a pre-approved drug that suppresses abnormally activated Wnt/β-catenin signaling and has a potency to reduce joint pathology in OA. We introduced the TOPFlash reporter plasmid into HCS-2/8 human chondrosarcoma cells to estimate the Wnt/β-catenin activity in the presence of 10 μM each compound in a panel of pre-approved drugs. We found that fluoxetine, an antidepressant in the class of selective serotonin reuptake inhibitors (SSRI), down-regulated Wnt/β-catenin signaling in human chondrosarcoma cells. Fluoxetine inhibited both Wnt3A- and LiCl-induced loss of proteoglycans in chondrogenically differentiated ATDC5 cells. Fluoxetine increased expression of Sox9 (the chondrogenic master regulator), and decreased expressions of Axin2 (a marker for Wnt/β-catenin signaling) and Mmp13 (matrix metalloproteinase 13). Fluoxetine suppressed a LiCl-induced increase of total β-catenin and a LiCl-induced decrease of phosphorylated β-catenin in a dose-dependent manner. An in vitro protein-binding assay showed that fluoxetine enhanced binding of β-catenin with Axin1, which is a scaffold protein forming the degradation complex for β-catenin. Fluoxetine suppressed LiCl-induced β-catenin accumulation in human OA chondrocytes. Intraarticular injection of fluoxetine in a rat OA model ameliorated OA progression and suppressed β-catenin accumulation. Topics: Animals; Axin Protein; Cartilage, Articular; Cell Differentiation; Cells, Cultured; Chondrocytes; Chondrogenesis; Disease Models, Animal; Down-Regulation; Fluoxetine; Humans; Lithium Chloride; Matrix Metalloproteinase 13; Osteoarthritis; Phosphorylation; Rats; Rats, Sprague-Dawley; Selective Serotonin Reuptake Inhibitors; SOX9 Transcription Factor; Wnt Signaling Pathway | 2017 |
The expression of G protein-coupled receptor kinase 5 and its interaction with dendritic marker microtubule-associated protein-2 after status epilepticus.
Acute seizures induced dendritic formation and synaptogenesis promotes aberrant circuitry development and further aggravates underlying conditions towards chronic epilepsy. The G protein-coupled receptor kinase-5 (GRK5) served as a key modulator in neurogenesis and the establishment of functional neuronal circuitry. This included dendritic development, as its dysfunction could cause different central nervous system disorders, including Alzheimer's disease. However, the involvement of GRK5 in the progression of epilepsy remains unclear. The purpose of this study is to investigate the involvement of GRK5 in epilepsy, as well as its potential correlation with dendritic formation after status epilepticus.. 120 rats were divided into control and model groups. The rats in the model group were injected intraperitoneally with lithium chloride-pilocarpine hydrochloride to establish the rat model of status epilepticus (SE). The brain and hippocampus were collected at 1, 3, 7, 14 and 28days post SE induction. The expression and distribution of GRK5 and the dendritic marker microtubule-associated protein-2 (MAP-2) were detected in the hippocampus via western blot or immunohistochemistry. The co-localization of GRK5 with MAP-2 was examined via laser confocal double immunofluorescence staining. The interactions between GRK5 and MAP-2 during epileptogenesis were evaluated via immunoprecipitation.. GRK5 was distributed in all areas of the hippocampus. Its expression was significantly up-regulated in the hippocampal CA1, DG, and H areas at 7d and 14d after SE. After 14d it began to reduce. and then reduced. MAP-2 primarily existed in the neuronal dendrites of the hippocampal subregion. Its expression was enhanced at 3d. It reached its maximum level at 14d after SE, where it then began to fall. The confocal microscope analysis revealed that GRK5 was co-located well within MAP-2 positive cells. The interaction between GRK5 and MAP-2 became enhanced at 7d and 14d after SE.. GRK5 was involved in the development of epilepsy. It was associated with dendritic formation in epilepsy. This study provides a new perspective for elucidating the epilepsy pathogenesis. The concrete mechanisms of the GRK5 within epileptogenesis require further research. Topics: Analysis of Variance; Animals; Disease Models, Animal; G-Protein-Coupled Receptor Kinase 5; Hippocampus; Immunoprecipitation; Lithium Chloride; Male; Microscopy, Confocal; Microtubule-Associated Proteins; Muscarinic Agonists; Muscarinic Antagonists; Pilocarpine; Rats; Rats, Sprague-Dawley; Scopolamine; Status Epilepticus; Time Factors | 2017 |
Response of the Tail of the Ventral Tegmental Area to Aversive Stimuli.
The GABAergic tail of the ventral tegmental area (tVTA), also named rostromedial tegmental nucleus (RMTg), exerts an inhibitory control on dopamine neurons of the VTA and substantia nigra. The tVTA has been implicated in avoidance behaviors, response to drugs of abuse, reward prediction error, and motor functions. Stimulation of the lateral habenula (LHb) inputs to the tVTA, or of the tVTA itself, induces avoidance behaviors, which suggests a role of the tVTA in processing aversive information. Our aim was to test the impact of aversive stimuli on the molecular recruitment of the tVTA, and the behavioral consequences of tVTA lesions. In rats, we assessed Fos response to lithium chloride (LiCl), β-carboline, naloxone, lipopolysaccharide (LPS), inflammatory pain, neuropathic pain, foot-shock, restraint stress, forced swimming, predator odor, and opiate withdrawal. We also determined the effect of tVTA bilateral ablation on physical signs of opiate withdrawal, and on LPS- and LiCl-induced conditioned taste aversion (CTA). Naloxone-precipitated opiate withdrawal induced Fos in μ-opioid receptor-positive (15%) and -negative (85%) tVTA cells, suggesting the presence of both direct and indirect mechanisms in tVTA recruitment during withdrawal. However, tVTA lesion did not impact physical signs of opiate withdrawal. Fos induction was also present with repeated, but not single, foot-shock delivery. However, such induction was mostly absent with other aversive stimuli. Moreover, tVTA ablation had no impact on CTA. Although stimulation of the tVTA favors avoidance behaviors, present findings suggest that this structure may be important to the response to some, but not all, aversive stimuli. Topics: Animals; Antimanic Agents; Behavior, Animal; Carbolines; Conditioning, Classical; Disease Models, Animal; Lipopolysaccharides; Lithium Chloride; Male; Morphine Dependence; Naloxone; Narcotic Antagonists; Neuralgia; Neurotoxins; Olfactory Perception; Pain; Proto-Oncogene Proteins c-fos; Rats; Rats, Sprague-Dawley; Receptors, Opioid, mu; Substance Withdrawal Syndrome; Ventral Tegmental Area | 2017 |
GSK-3β Interacts with Dopamine D1 Receptor to Regulate Receptor Function: Implication for Prefrontal Cortical D1 Receptor Dysfunction in Schizophrenia.
Impaired dopamine D1 receptor (D1R) function in prefrontal cortex (PFC) is believed to contribute to the PFC hypofunction that has been hypothesized to be associated with negative symptoms and cognitive deficits in schizophrenia. It is therefore critical to understand the mechanisms for modulation of D1R function.. To investigate the physical interaction and functional modulation between D1R and GSK-3β.. D1R and GSK-3β physically interact in cultured cells and native brain tissues. This direct interaction was found to occur at the S(417)PALS(421) motif in the C-terminus of D1R. Inhibition of GSK-3β impaired D1R activation along with a decrease in D1R-GSK-3β interaction. GSK-3β inhibition reduced agonist-stimulated D1R desensitization and endocytosis, the latter associated with the reduction of membrane translocation of β-arrestin-2. Similarly, inhibition of GSK-3β in rat PFC also resulted in impaired D1R activation and association with GSK-3β. Moreover, in a NMDA antagonist animal model of schizophrenia, we detected a decrease in prefrontal GSK-3β activity and D1R-GSK-3β association and decreased D1R activation in the PFC.. The present work identified GSK-3β as a new interacting protein for D1R functional regulation and revealed a novel mechanism for GSK-3β-regulated D1R function which may underlie D1R dysfunction in schizophrenia. Topics: Adjuvants, Immunologic; Animals; beta-Arrestins; Cyclic AMP; Disease Models, Animal; Dopamine Agonists; Endocytosis; Enzyme Inhibitors; Fenoldopam; Glycogen Synthase Kinase 3 beta; Guanosine 5'-O-(3-Thiotriphosphate); HEK293 Cells; Humans; Indoles; Lithium Chloride; Maleimides; Prefrontal Cortex; Protein Transport; Rats; Receptors, Dopamine D1; Schizophrenia | 2017 |
Lithium increases hippocampal SNARE protein abundance after traumatic brain injury.
Rodent models of traumatic brain injury (TBI) reproduce secondary injury sequela and cognitive impairments observed in patients afflicted by a TBI. Impaired neurotransmission has been reported in the weeks following experimental TBI, and may be a contributor to behavioral dysfunction. The soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) complex, the machinery facilitating vesicular docking and fusion, is a highly-conserved mechanism important for neurotransmission. Following TBI, there is a reduction in both the formation of the SNARE complex and the abundance of multiple SNARE proteins, including the chaperone protein cysteine string protein α (CSPα). Treatment with lithium in naïve rats reportedly increases the expression of CSPα. In the context of TBI, brain-injured rats treated with lithium exhibit improved outcome in published reports, but the mechanisms underlying the improvement are poorly understood. The current study evaluated the effect of lithium administration on the abundance of SNARE proteins and SNARE complex formation, hemispheric tissue loss, and neurobehavioral performance following controlled cortical impact (CCI). Sprague Dawley rats were subjected to CCI or sham injury, and treated daily with lithium chloride or vehicle for up to 14days. Administration of lithium after TBI modestly improved spatial memory at 14days post-injury. Semi-quantitative immunoblot analysis of hippocampal lysates revealed that treatment with lithium attenuated reductions in key SNARE proteins and SNARE complex formation at multiple time points post-injury. These findings highlight that treatment with lithium increased the abundance of synaptic proteins that facilitate neurotransmission and may contribute to improved cognitive function after TBI. Topics: alpha-Synuclein; Analysis of Variance; Animals; Antimanic Agents; Brain Injuries, Traumatic; Disease Models, Animal; Gene Expression Regulation; Hippocampus; Learning Disabilities; Lithium Chloride; Male; Psychomotor Disorders; Rats; Rats, Sprague-Dawley; SNARE Proteins; Spatial Learning; Synaptophysin; Synaptosomal-Associated Protein 25; Time Factors; Vesicle-Associated Membrane Protein 2 | 2017 |
Galanin contributes to monoaminergic dysfunction and to dependent neurobehavioral comorbidities of epilepsy.
Status epilepticus (SE) in rats, along with chronic epilepsy, leads to the development of behavioral impairments resembling depressive disorder and/or attention deficit/hyperactivity disorder (ADHD), thus reflecting respective comorbidities in epilepsy patients. Suppressed neurotransmitter tone in the raphe nucleus (RN)-prefrontal cortex (PFC) serotonergic pathway and in the locus coeruleus (LC)-PFC noradrenergic pathway underlies depressive- and impulsive-like behavioral deficits respectively. We examined possible mechanisms leading to the monoamine dysfunction in brainstem efferents, namely modulatory effects of the neuropeptide galanin on serotonin (5-HT) and norepinephrine (NE) signaling. SE was induced in young adult male Wistar rats by LiCl and pilocarpine. Epileptic rats were categorized vis-à-vis behavioral deficits as not impaired, "depressed" and "impulsive". Depressive- and impulsive-like behaviors were examined in the forced swimming test (FST). The strength of serotonergic transmission in RN-PFC and of noradrenergic transmission in LC-PFC was analyzed using in vivo fast scan cyclic voltammetry. Galanin receptor type 1 (GalR1)/type 2 (GalR2) antagonist M40, and a preferential GalR2 antagonist M871 were administered over 3days locally into either RN or LC by means of ALZET osmotic minipumps connected to locally implanted infusion cannulas. Intra-RN injection of M40 improved serotonergic tone and depressive-like behavior in epileptic "depressed" rats. Intra-LC injection of M40 improved noradrenergic tone and impulsive-like behavior in epileptic "impulsive" rats. The effects of M40 were only observed in impaired subjects. The treatment did not modify neurotransmission and behavior in naïve and epileptic not impaired rats; in "depressed" rats the effects were limited to serotonergic transmission and immobility, while in "impulsive" rats - to noradrenergic transmission and struggling behavior. Intra-RN administration of M871 exacerbated depressive-like behavior, but had no effects on any other of the examined parameters in any category of animals. These findings suggest that endogenous galanin, acting through GalR1 may be involved in the pathophysiology of epilepsy-associated depression and ADHD via inhibiting RN-PFC serotonergic and LC-PFC noradrenergic transmissions respectively. Topics: Animals; Antidepressive Agents; Biogenic Monoamines; Depression; Disease Models, Animal; Drug Delivery Systems; Galactolipids; Galanin; Impulsive Behavior; Lithium Chloride; Locus Coeruleus; Male; Muscarinic Agonists; Peptide Fragments; Pilocarpine; Raphe Nuclei; Rats; Rats, Wistar; Serotonin; Status Epilepticus; Swimming | 2017 |
Lithium-induced malaise does not interfere with adaptation of the hypothalamic-pituitary-adrenal axis to stress.
We have recently demonstrated that adaptation of the hypothalamic-pituitary-adrenal (HPA) axis to repeated exposure to a stressor does not follow the rules of habituation and can be fully expressed after a single experience with severe stressors. In the present work we tested the hypothesis that adaptation could be impaired if animals experience malaise during initial exposure to the stressor. To this end, animals were allowed to drink saccharin for 30min before being exposed for 3h to immobilization on boards (IMO), a severe stressor; then they were given either saline or lithium ip after the first hour of IMO. Stress-naïve rats followed exactly the same procedure except IMO. Exposure to IMO caused a strong activation of the HPA axis whereas the effect of lithium was modest. Both IMO and lithium administration resulted in conditioned taste aversion to saccharin when evaluated 4days later. When all animals were exposed to IMO 6days later, reduced HPA response and less impact on body weight was observed in the two groups previously exposed to IMO as compared with stress-naïve rats. Therefore, lithium administration during the first IMO exposure did not affect adaptation of the HPA axis and weight gain. These results indicate that malaise per se only weakly activated the HPA axis and argue against the hypothesis that signs of physical malaise during exposure to the stressor could impair HPA adaptation. Topics: Adaptation, Physiological; Adrenocorticotropic Hormone; Animals; Antimanic Agents; Body Weight; Corticosterone; Disease Models, Animal; Hypothalamo-Hypophyseal System; Lithium Chloride; Male; Pituitary-Adrenal System; Radioimmunoassay; Rats; Rats, Sprague-Dawley; Saccharin; Stress, Psychological; Time Factors | 2017 |
Which component of treatment is important for changes of cortical epileptic afterdischarges after status epilepticus in immature rats?
Role of lithium chloride and paraldehyde in acute changes after lithium-pilocarpine status epilepticus (SE) induced at postnatal day 12 was studied in 15-day-old rats. In addition to SE group four other groups were formed: naïve animals without any injection, lithium chloride group, paraldehyde group and lithium-paraldehyde group. Cortical epileptic afterdischarges (CxADs) induced by increasing intensities of stimulation current were used as a measure of excitability. SE animals did not exhibit any change in duration of CxADs with increasing stimulation intensity in contrast to naïve control with a progressive prolongation of CxAD. LiCl group was similar to SE rats whereas paraldehyde and lithium-paraldehyde groups exhibited some progress in duration of ADs. Lithium chloride participates in short-term changes of CxADs after SE. Paraldehyde and combination of lithium and paraldehyde are similar to naïve controls. Topics: Animals; Anticonvulsants; Cerebral Cortex; Convulsants; Disease Models, Animal; Lithium Chloride; Male; Paraldehyde; Pilocarpine; Rats; Rats, Wistar; Status Epilepticus | 2017 |
Direct Keap1-Nrf2 disruption as a potential therapeutic target for Alzheimer's disease.
Nrf2, a transcriptional activator of cell protection genes, is an attractive therapeutic target for the prevention of neurodegenerative diseases, including Alzheimer's disease (AD). Current Nrf2 activators, however, may exert toxicity and pathway over-activation can induce detrimental effects. An understanding of the mechanisms mediating Nrf2 inhibition in neurodegenerative conditions may therefore direct the design of drugs targeted for the prevention of these diseases with minimal side-effects. Our study provides the first in vivo evidence that specific inhibition of Keap1, a negative regulator of Nrf2, can prevent neuronal toxicity in response to the AD-initiating Aβ42 peptide, in correlation with Nrf2 activation. Comparatively, lithium, an inhibitor of the Nrf2 suppressor GSK-3, prevented Aβ42 toxicity by mechanisms independent of Nrf2. A new direct inhibitor of the Keap1-Nrf2 binding domain also prevented synaptotoxicity mediated by naturally-derived Aβ oligomers in mouse cortical neurons. Overall, our findings highlight Keap1 specifically as an efficient target for the re-activation of Nrf2 in AD, and support the further investigation of direct Keap1 inhibitors for the prevention of neurodegeneration in vivo. Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Animals, Genetically Modified; Blotting, Western; Cell Line, Tumor; Cells, Cultured; Disease Models, Animal; Drosophila melanogaster; Drosophila Proteins; Gene Expression Profiling; Glycogen Synthase Kinase 3; Humans; Kelch-Like ECH-Associated Protein 1; Lithium Chloride; Longevity; Mice; Microscopy, Confocal; Neurons; NF-E2-Related Factor 2; Oleanolic Acid; Peptide Fragments; Protein Binding; Reverse Transcriptase Polymerase Chain Reaction; Thiadiazoles; Triazoles | 2017 |
Increased Expression of Rac1 in Epilepsy Patients and Animal Models.
The mechanisms of epilepsy remain incompletely understood. Rac1 (ras-related C3 botulinum toxin substrate 1) belongs to the Rho family of small GTPases. Rac1 play important roles in cytoskeleton rearrangement and neuronal synaptic plasticity, which had also been implicated in epilepsy. However, little is known regarding the expression of Rac1 in the epileptic brain or whether Rac1-targeted interventions affect the progression of epilepsy. The aim of this study was to investigate the expression profile of Rac1 in brain tissues from patients suffering from temporal lobe epilepsy (TLE) and experimental epileptic rats and determine the possible role of Rac1 in epilepsy. We demonstrated that the expression of Rac1 is significantly increased in TLE patients and in lithium-pilocarpine epilepsy model animals compared to the corresponding controls. Rac1 inhibitor NSC23766 reduced the severity of status epilepticus during the acute stage in a lithium-pilocarpine animal model. Consistent with these results, the latent period of a PTZ kindling animal model also increased. Our results demonstrated that the increased expression of Rac1 may contribute to pathophysiology of epilepsy. Topics: Adult; Aminoquinolines; Animals; Behavior, Animal; Brain; Case-Control Studies; Disease Models, Animal; Epilepsy; Female; Humans; Kindling, Neurologic; Lithium Chloride; Male; Pilocarpine; Pyrimidines; rac1 GTP-Binding Protein; Rats, Sprague-Dawley | 2016 |
The pervasive reduction of GABA-mediated synaptic inhibition of principal neurons in the hippocampus during status epilepticus.
The goal of this study was to determine whether there are region-specific or time-dependent changes in GABA-mediated synaptic inhibition of principal neurons in the hippocampus during in vivo status epilepticus. Standard whole cell patch clamp electrophysiological techniques were used to characterize miniature inhibitory postsynaptic currents (mIPSCs) in recordings from the principal neurons (PNs) of the dentate gyrus, CA1, and CA3 in acutely-obtained hippocampal slices from control and lithium/pilocarpine-induced status epilepticus(SE)-treated animals. The reduction in mIPSC amplitude was pervasive across the 3 regions examined in hippocampal slices obtained after 60 min (late) or just 15 min after the onset of SE. The mIPSC frequency was reduced in all 3 regions after 60 min and 2 regions (dentate, CA1) after 15 min. These findings lend further support to the hypothesis that a rapid modification of the postsynaptic GABAA receptor population leads to a widespread decline in GABA-mediated inhibition that, in part, contributes to both the self-sustaining nature of SE and to the decrease in the efficacy of benzodiazepines. Topics: Animals; Disease Models, Animal; gamma-Aminobutyric Acid; Hippocampus; Inhibitory Postsynaptic Potentials; Lithium Chloride; Male; Miniature Postsynaptic Potentials; Neurons; Patch-Clamp Techniques; Pilocarpine; Rats, Sprague-Dawley; Status Epilepticus; Time; Tissue Culture Techniques | 2016 |
A sub-threshold dose of pilocarpine increases glutamine synthetase in reactive astrocytes and enhances the progression of amygdaloid-kindling epilepsy in rats.
The prognosis of patients exposed to a sub-threshold dose of a proconvulsant is difficult to establish. In this study, we investigated the effect of a single sub-threshold dose of the proconvulsant pilocarpine (PILO) on the progression of seizures that were subsequently induced by daily electrical stimulation (kindling) of the amygdaloid formation. Male Sprague–Dawley rats were each implanted with an electrode in the right basolateral amygdala and an indwelling cannula in the right ventricle. The animals were randomized into groups and were administered one of the following treatments: saline, PILO, saline+L-α-aminoadipic acid (L-AAA; one dosage tested), PILO+L-AAA, or PILO+L-methionine sulfoximine (three dosages tested). Amygdaloid stimulation and electroencephalography were performed once daily. We performed immunohistochemistry and western blot for glial fibrillary acidic protein and glutamine synthetase (GS). We also assayed the enzymic activity of GS in discrete brain regions. An intraperitoneal injection of a sub-threshold PILO dose enhanced the progression of amygdaloid-kindling seizures and was accompanied by an increase in reactive-astrocyte and GS (content and activity) in the hippocampus and piriform cortex. L-AAA and L-methionine sulfoximine, inhibitors of astrocytic and GS function, respectively, abolished the effect of PILO on amygdaloid-kindling seizures. We conclude that one sub-threshold dose of a proconvulsant may enhance the progression of subsequent epilepsy and astrocytic GS may play a role in this phenomenon. Thus, a future therapy for epilepsy could be inhibition of astrocytes and/or GS. Topics: 2-Aminoadipic Acid; Animals; Astrocytes; Basolateral Nuclear Complex; Catheters, Indwelling; Disease Models, Animal; Electric Stimulation; Electrodes, Implanted; Fluorescent Antibody Technique; Glial Fibrillary Acidic Protein; Glutamate-Ammonia Ligase; Hippocampus; Kindling, Neurologic; Lithium Chloride; Male; Methionine Sulfoximine; Muscarinic Agonists; Pilocarpine; Rats, Sprague-Dawley; Temporal Lobe | 2016 |
N-methyl-D-aspartate receptor NR2B subunit involved in depression-like behaviours in lithium chloride-pilocarpine chronic rat epilepsy model.
Depression is a common comorbidity in patients with epilepsy with unclear mechanisms. This study is to explore the role of glutamate N-methyl-D-aspartate (NMDA) receptor NR1, NR2A and NR2B subunits in epilepsy-associated depression. Lithium chloride (Licl)-pilocarpine chronic rat epilepsy model was established and rats were divided into epilepsy with depression (EWD) and epilepsy without depression (EWND) subgroups based on forced swim test. Expression of NMDA receptor NR1, NR2A and NR2B subunits was measured by western blot and immunofluorescence methods. The immobility time (IMT) was significantly greater in Licl-pilocarpine model group than in Control group, which was also greater in EWD group than in EWND group. No differences of spontaneous recurrent seizure (SRS) counts over two weeks and latency were found between EWD and EWND groups. The number of NeuN positive cells was significantly less in Licl-pilocarpine model group than in Control group, but had no difference between EWD and EWND groups. The ratios of phosphorylated NR1 (p-NR1)/NR1 and p-NR2B/NR2B were significantly greater in the hippocampus in EWD group than in EWND group. Moreover, the expression of p-NR1 and p-NR2B in the CA1 subfield of hippocampus were both greater in Licl-pilocarpine model group than Control group. Selective blockage of NR2B subunit with ifenprodil could alleviate depression-like behaviours of Licl-pilocarpine rat epilepsy model. In conclusion, glutamate NMDA receptor NR2B subunit was involved in promoting depression-like behaviours in the Licl-pilocarpine chronic rat epilepsy model and might be a target for treating epilepsy-associated depression. Topics: Animals; Antigens, Nuclear; Chronic Disease; Depressive Disorder; Disease Models, Animal; Epilepsy; Hippocampus; Lithium Chloride; Male; Nerve Tissue Proteins; Neurons; Phosphorylation; Pilocarpine; Rats, Sprague-Dawley; Receptors, N-Methyl-D-Aspartate; Seizures | 2016 |
A two-hit model of suicide-trait-related behaviors in the context of a schizophrenia-like phenotype: Distinct effects of lithium chloride and clozapine.
Schizophrenia patients show a high rate of premature mortality due to suicide. The pathophysiological mechanisms of these suicidal behaviors in schizophrenia do not appear to involve serotonergic neurotransmission as found in the general population. Our aim was to develop an in vivo model of schizophrenia presenting suicide-trait-related behaviors such as aggressiveness, impulsivity, anxiety and helplessness. We opted for a two-hit model: C57BL/6 dams were injected with polyI:C on gestational day 12. The pups were submitted to social isolation for 4weeks after weaning. During the last week of social isolation and 30min before behavioral testing, the mice received vehicle, lithium chloride or clozapine. Lithium chloride is well known for its suicide preventive effects in the non-schizophrenic population, while clozapine is the antipsychotic with the best-established suicide preventive effect. The two-hit model induced several schizophrenia-related and suicide-trait-related behaviors in male, but not female, mice. Additionally, lithium chloride improved prepulse inhibition, aggressiveness, impulsivity and anxiety-like behavior in socially isolated mice only, whereas clozapine prevented behavioral abnormalities mainly in mice prenatally exposed to polyI:C and submitted to isolated rearing. The distinct effects of lithium chloride and clozapine suggested that mice prenatally exposed to polyI:C and submitted to social isolation presented a distinct phenotype from that of mice submitted to social isolation only. Because diagnosing suicidal risk in patients is a challenge for psychiatrists given the lack of specific clinical predictors, our in vivo model could help in gaining a better understanding of the mechanisms underlying suicidal behavior in the context of schizophrenia. Topics: Aggression; Animals; Antipsychotic Agents; Anxiety; Clozapine; Disease Models, Animal; Female; Lithium Chloride; Mice; Mice, Inbred C57BL; Phenotype; Schizophrenia; Schizophrenic Psychology; Social Isolation; Suicidal Ideation; Suicide Prevention | 2016 |
GSK-3β downregulates Nrf2 in cultured cortical neurons and in a rat model of cerebral ischemia-reperfusion.
The NF-E2-related factor 2 (Nrf2)/antioxidant response element (ARE) pathway plays a critical role in protecting against oxidative stress in brain ischemia and reperfusion injury. Glycogen synthase kinase 3β (GSK-3β) may play a critical role in regulating Nrf2 in a Kelch-like ECH-associated protein 1 (Keap1)-independent manner. However, the relationship between GSK-3β and Nrf2 in brain ischemia and reperfusion injury is not clear. In this study, we explored the mechanisms through which GSK-3β regulates Nrf2 and Nrf-2/ARE pathways in vitro and in vivo. We used oxygen and glucose deprivation/reoxygenation (OGD/R) in primary cultured cortical neurons and a middle cerebral artery occlusion-reperfusion (MCAO/R) rat model to mimic ischemic insult. In this study, GSK-3β siRNA and inhibitors (SB216763 and LiCl) were used to inhibit GSK-3β in vitro and in vivo. After inhibiting GSK-3β, expression of total and nuclear Nrf2, Nrf2-ARE binding activity, and expression of Nrf2/ARE pathway-driven genes HO-1 and NQO-1 increased. Overexpression of GSK-3β yielded opposite results. These results suggest that GSK-3β downregulates Nrf2 and the Nrf2/ARE pathway in brain ischemia and reperfusion injury. GSK-3β may be an endogenous antioxidant relevant protein, and may represent a new therapeutic target in treatment of ischemia and reperfusion injury. Topics: Animals; Brain Ischemia; Cells, Cultured; Disease Models, Animal; Down-Regulation; Gene Expression Regulation; Gene Silencing; Glycogen Synthase Kinase 3 beta; Indoles; Lithium Chloride; Male; Maleimides; Neurons; NF-E2-Related Factor 2; Rats; Signal Transduction | 2016 |
Targeting of microRNA-199a-5p protects against pilocarpine-induced status epilepticus and seizure damage via SIRT1-p53 cascade.
MicroRNAs (miRNAs) are noncoding small RNAs that control gene expression at the posttranscriptional level. Some dysregulated miRNAs have been shown to play important roles in epileptogenesis. The aim of this study was to determine if miR-199a-5p regulates seizures and seizure damage by targeting the antiapoptotic protein silent information regulator 1 (SIRT1).. Hippocampal expression levels of miR-199a-5p, SIRT1, and acetylated p53 were quantified by quantitative real-time polymerase chain reaction (RT-PCR) and Western blotting in the acute, latent, and chronic stages of epilepsy in a rat lithium-pilocarpine epilepsy model. Silencing of miR-199a-5p expression in vivo was achieved by intracerebroventricular injection of antagomirs. The effects of targeting miR-199a-5p and SIRT1 protein on seizure and epileptic damage post-status epilepticus were assessed by electroencephalography (EEG) and immunohistochemistry, respectively.. miR-199a-5p expression was up-regulated, SIRT1 levels were decreased, and neuron loss and apoptosis were induced in epilepsy model rats compared with normal controls, as determined by up-regulation of acetylated p53 and cleaved caspase-3 expression. In vivo knockdown of miR-199a-5p by an antagomir alleviated the seizure-like EEG findings and protected against neuron damage, in accordance with up-regulation of SIRT1 and subsequent deacetylation of p53. Furthermore, the seizure-suppressing effect of the antagomir was partly SIRT1 dependent.. The results of this study suggest that silencing of miR-199a-5p exerts a seizure-suppressing effect in rats, and that SIRT1 is a direct target of miR-199a-5p in the hippocampus. The effect of miR-199a-5p on seizures and seizure damage is mediated via down-regulation of SIRT1. The miR-199a-5p/SIRT1 pathway may thus represent a potential target for the prevention and treatment of epilepsy and epileptic damage. Topics: Animals; Anticonvulsants; Apoptosis; Argonaute Proteins; Carbazoles; Convulsants; Disease Models, Animal; Hippocampus; Lithium Chloride; Male; MicroRNAs; Neurons; Oligonucleotides, Antisense; Pilocarpine; Rats; Rats, Sprague-Dawley; Signal Transduction; Sirtuin 1; Status Epilepticus; Tumor Suppressor Protein p53; Up-Regulation | 2016 |
Preconditioning mesenchymal stem cells with the mood stabilizers lithium and valproic acid enhances therapeutic efficacy in a mouse model of Huntington's disease.
Huntington's disease (HD) is a fatal neurodegenerative disorder caused by CAG repeat expansions in the huntingtin gene. Although, stem cell-based therapy has emerged as a potential treatment for neurodegenerative diseases, limitations remain, including optimizing delivery to the brain and donor cell loss after transplantation. One strategy to boost cell survival and efficacy is to precondition cells before transplantation. Because the neuroprotective actions of the mood stabilizers lithium and valproic acid (VPA) induce multiple pro-survival signaling pathways, we hypothesized that preconditioning bone marrow-derived mesenchymal stem cells (MSCs) with lithium and VPA prior to intranasal delivery to the brain would enhance their therapeutic efficacy, and thereby facilitate functional recovery in N171-82Q HD transgenic mice. MSCs were treated in the presence or absence of combined lithium and VPA, and were then delivered by brain-targeted single intranasal administration to eight-week old HD mice. Histological analysis confirmed the presence of MSCs in the brain. Open-field test revealed that ambulatory distance and mean velocity were significantly improved in HD mice that received preconditioned MSCs, compared to HD vehicle-control and HD mice transplanted with non-preconditioned MSCs. Greater benefits on motor function were observed in HD mice given preconditioned MSCs, while HD mice treated with non-preconditioned MSCs showed no functional benefits. Moreover, preconditioned MSCs reduced striatal neuronal loss and huntingtin aggregates in HD mice. Gene expression profiling of preconditioned MSCs revealed a robust increase in expression of genes involved in trophic effects, antioxidant, anti-apoptosis, cytokine/chemokine receptor, migration, mitochondrial energy metabolism, and stress response signaling pathways. Consistent with this finding, preconditioned MSCs demonstrated increased survival after transplantation into the brain compared to non-preconditioned cells. Our results suggest that preconditioning stem cells with the mood stabilizers lithium and VPA before transplantation may serve as an effective strategy for enhancing the therapeutic efficacy of stem cell-based therapies. Topics: Animals; Antimanic Agents; Cytokines; Disease Models, Animal; Dopamine and cAMP-Regulated Phosphoprotein 32; Drug Administration Schedule; Female; Gene Expression; Huntingtin Protein; Huntington Disease; Lithium Chloride; Male; Mesenchymal Stem Cell Transplantation; Mesenchymal Stem Cells; Mice; Mice, Inbred C57BL; Mice, Transgenic; Mutation; Phosphopyruvate Hydratase; Proto-Oncogene Proteins c-kit; Receptors, Cytokine; Up-Regulation; Valproic Acid | 2016 |
Influence of early life status epilepticus on the developmental expression profile of the GluA2 subunit of AMPA receptors.
AMPA receptors (AMPARs) are responsible for fast excitatory neurotransmission, and their prolonged activation can result in the generation and spread of epileptic seizures. At early stages of postnatal development, the majority of AMPARs are permeable to both Na(+) and Ca(2+) ions. This permeability, which increases neuronal excitability, is due to the lack of the GluA2 subunit, encoded by the GRIA2A gene, and/or the presence of an unedited GluA2 subunit Q/R site (glutamine instead of arginine). Lithium chloride- and pilocarpine-induced status epilepticus (LiCl/Pilo-SE) in rodents represents a model of severe seizures that result in development of temporal lobe epilepsy (TLE). The aim of this study was to determine how LiCl/Pilo-SE induced early in life (at postnatal day 12; P12) alters normal expression of the GRIA2A gene and GluA2 protein. SE was interrupted by an injection of paraldehyde (Para). Control groups were 1) naïve animals, and 2) siblings of SE rats receiving only LiCl and paraldehyde (LiCl/Para). The expression profile of GRIA2A mRNA was determined via qPCR, and GluA2 protein levels were measured by western blotting. The analysis was performed at 3h (protein levels), and then 3-, 6-, 13-, and 60days, following LiCl/Pilo-SE or LiCl/Para injection (i.e. at P12, P15, P18, P25, P72 respectively). Six different brain regions were analyzed: frontal (CXFR), parietal (CXPAR), and occipital (CXOC) cortex, dorsal (HD) and ventral (HV) hippocampus, and thalamus (TH). There was a significant increase in GRIA2A mRNA expression in the CXFR, CXPAR, and CXOC of P18 SE animals. In CXFR and HD, increased expression of GluA2 AMPAR subunit protein was detected, as well as a surge in GRIA2A mRNA and GluA2 protein expression especially at P18. In HD the surge was detected not only during development (P18), but also later in life (P72). Since high levels of GluA2 can be neuroprotective (by decreasing Ca(2+) permeability), our data suggest that the neocortex and dorsal hippocampus are able to activate endogenous antiepileptic mechanisms. A marked decrease in the overall expression of GluA2 protein in the HV in the LiCl/Pilo-SE and LiCl/Para rats, suggests that the HV is predisposed to excitotoxicity, not only during development, but even in adulthood. Interestingly, LiCl in combination with paraldehyde can also strongly alter the normal ontogeny of GRIA2A mRNA as well as GluA2 subunit protein expression. Topics: Age Factors; Animals; Animals, Newborn; Brain; Convulsants; Disease Models, Animal; Fluoresceins; Gene Expression Regulation, Developmental; Lithium Chloride; Male; Pilocarpine; Rats; Rats, Wistar; Receptors, AMPA; RNA, Messenger; Status Epilepticus | 2016 |
Extended cocaine-seeking produces a shift from goal-directed to habitual responding in rats.
Cocaine addiction is often characterized by a rigid pattern of behavior in which cocaine users continue seeking and taking drug despite negative consequences associated with its use. As such, full acquisition and relapse of drug-seeking behavior may be attributed to a shift away from goal-directed responding and a shift towards the maladaptive formation of rigid and habit-like responses. This rigid nature of habitual responding can be developed with extended training and is typically characterized by insensitivity to changes in outcome value. The present study determined whether cocaine (primary reinforcer) and cocaine associated cues (secondary reinforcer) could be devalued in rats with different histories of cocaine self-administration. Specifically, rats were trained on two schedules of cocaine self-administration (long-access vs. short-access). Following training the cocaine reinforcer was devalued through three separate pairings of lithium chloride with cocaine infusions. Cocaine history did not have an impact on devaluation of cocaine-associated cues. However, the reinforcing properties of cocaine were devalued only in rats on a short-access cocaine schedule but not those trained on a long-access schedule. Taken together this pattern of findings suggests that, in short access rats, devaluation is specific to the primary reinforcer and not associative stimuli such as cues. Importantly, rats that received extended training during self-administration displayed insensitivity to outcome devaluation of the primary reinforcer as well as all associative stimuli, thus displaying rigid behavioral responding similar to behavioral patterns found in addiction. Alternatively, long access cocaine exposure may have altered the devaluation threshold. Topics: Analysis of Variance; Animals; Cocaine; Cocaine-Related Disorders; Disease Models, Animal; Dopamine Uptake Inhibitors; Drug-Seeking Behavior; Extinction, Psychological; Goals; Habits; Lithium Chloride; Male; Rats, Sprague-Dawley; Self Administration; Time Factors | 2016 |
Midazolam-ketamine dual therapy stops cholinergic status epilepticus and reduces Morris water maze deficits.
Pharmacoresistance remains an unsolved therapeutic challenge in status epilepticus (SE) and in cholinergic SE induced by nerve agent intoxication. SE triggers a rapid internalization of synaptic γ-aminobutyric acid A (GABAA ) receptors and externalization of N-methyl-d-aspartate (NMDA) receptors that may explain the loss of potency of standard antiepileptic drugs (AEDs). We hypothesized that a drug combination aimed at correcting the consequences of receptor trafficking would reduce SE severity and its long-term consequences.. A severe model of SE was induced in adult Sprague-Dawley rats with a high dose of lithium and pilocarpine. The GABAA receptor agonist midazolam, the NMDA receptor antagonist ketamine, and/or the AED valproate were injected 40 min after SE onset in combination or as monotherapy. Measures of SE severity were the primary outcome. Secondary outcomes were acute neuronal injury, spontaneous recurrent seizures (SRS), and Morris water maze (MWM) deficits.. Midazolam-ketamine dual therapy was more efficient than double-dose midazolam or ketamine monotherapy or than valproate-midazolam or valproate-ketamine dual therapy in reducing several parameters of SE severity, suggesting a synergistic mechanism. In addition, midazolam-ketamine dual therapy reduced SE-induced acute neuronal injury, epileptogenesis, and MWM deficits.. This study showed that a treatment aimed at correcting maladaptive GABAA receptor and NMDA receptor trafficking can stop SE and reduce its long-term consequences. Early midazolam-ketamine dual therapy may be superior to monotherapy in the treatment of benzodiazepine-refractory SE. Topics: Animals; Anticonvulsants; Brain; Cholinergic Agents; Disease Models, Animal; Drug Synergism; Drug Therapy, Combination; Ketamine; Learning Disabilities; Lithium Chloride; Male; Maze Learning; Midazolam; N-Methylscopolamine; Pilocarpine; Rats; Rats, Sprague-Dawley; Status Epilepticus; Valproic Acid | 2016 |
The effects of edaravone in ketamine-induced model of mania in rats.
Bipolar disorder is a chronic disease characterized by recurring episodes of mania and depression that can lead to disability. This study investigates the protective effects of edaravone (3-methyl-1-phenyl-2-pyrazolin-5-one), a drug with well-known antioxidant properties, in a model of mania induced by ketamine in rats. Locomotor activity was assessed in the open-field test. Superoxide dismutase (SOD), catalase (CAT) and thiobarbituric acid reactive substances (TBARS) levels were measured in order to evaluate oxidative damage in the rat hippocampus and prefrontal cortex. Increased locomotor activity (hyperlocomotion) was observed at the open-field test with ketamine treatment (25 mg/kg, i.p., 8 days). Edaravone (18 mg/kg) treatment did not prevent hyperlocomotion in the mania model induced with ketamine in rats, but lithium chloride (47.5 mg/kg, i.p., positive control) did prevent hyperlocomotion. Edaravone and lithium chloride treatments were found to reduce the increase in SOD and CAT activity following ketamine administration in a non-significant manner but caused no change in TBARS levels. Topics: Analysis of Variance; Animals; Antimanic Agents; Antipyrine; Bipolar Disorder; Brain; Catalase; Disease Models, Animal; Drug Administration Schedule; Edaravone; Excitatory Amino Acid Antagonists; Exploratory Behavior; Female; Ketamine; Lithium Chloride; Locomotion; Malondialdehyde; Neuroprotective Agents; Rats; Rats, Sprague-Dawley; Superoxide Dismutase | 2016 |
Glycogen synthase kinase‑3β is required for epithelial‑mesenchymal transition and barrier dysfunction in mouse podocytes under high glucose conditions.
Epithelial-mesenchymal transition (EMT) is important for diabetic nephropathy (DN). Podocytes are specialized epithelial cells, which form a major component of the glomerular filtration barrier. Podocyte damage has been suggested to be the primary mechanism behind the albuminuria associated with DN. The present study aimed to determine the function of glycogen synthase kinase (GSK)‑3β in EMT and barrier dysfunction of mouse podocytes exposed to high glucose (HG) conditions. Matured and differentiated podocytes were treated with normal glucose (NG), HG or NG + mannitol. Podocytes were also transfected with a small interfering RNA (siRNA) against GSK‑3β or a scrambled siRNA, or were treated with lithium chloride (LiCl), a GSK‑3β inhibitor, under NG or HG conditions. The expression levels of the epithelial cell markers, nephrin and podocin, and the myofibroblast cell markers, α‑smooth muscle actin (SMA) and fibronectin, in podocytes by western blot analysis and immunofluorescence staining, respectively. The monolayer barrier function was assessed by albumin inflow. The phosphorylation and activity levels of GSK‑3β were also quantified. It was observed that HG promotes EMT in podocytes, due to the increased levels of podocin and nephrin expression and the reduced α‑SMA and fibronectin expression levels. HG also induced barrier dysfunction and increased the expression level of total GSK‑3β, Try216‑phosphorylated‑GSK‑3β and the GSK‑3β activity in podocytes. Transfection of GSK‑3β siRNA or treatment with LiCl reversed the HG‑induced EMT and barrier dysfunction in podocytes. In conclusion, the present study determined that GSK‑3β is required for EMT and barrier dysfunction in podocytes under HG conditions; therefore, GSK‑3β may be a novel target for the treatment of DN. Topics: Actins; Animals; Diabetic Nephropathies; Disease Models, Animal; Epithelial-Mesenchymal Transition; Gene Expression Regulation; Glomerular Filtration Barrier; Glucose; Glycogen Synthase Kinase 3 beta; Humans; Intracellular Signaling Peptides and Proteins; Lithium Chloride; Membrane Proteins; Mice; Podocytes; RNA, Small Interfering | 2016 |
Protective effects of lithium chloride treatment on repeated cerebral ischemia-reperfusion injury in mice.
Lithium is a renowned pharmacological treatment for mood disorders. Recent studies suggest that lithium chloride (LiCl) performs neuroprotective effects on cerebrovascular diseases. The present study is to investigate the protective effects of LiCl treatment on the hippocampus of mice with repeated cerebral ischemia-reperfusion (IR). Mice were subjected to IR through repeated bilateral common carotid artery occlusion. LiCl (2 mmol/kg) was administered daily postoperative until the mice were sacrificed. Swimming time was prolonged and error count increased in the model group through learning and memory tests. Pathological changes such as reduction in cell count and obvious pyknosis were seen in haematoxylin-eosin staining, and apoptosis was detected by TUNEL staining in hippocampal CA1 regions in the model group. The model animals exhibited more phospho-Akt Ser473 and phospho-GSK3β Ser9 than the sham group when measured by Western blot. LiCl treatment mitigated the prolonged swimming time and the increased error count compared with NaCl-treated group and improved the pathological changes. Meanwhile, LiCl further up-regulated phospho-Akt Ser473 and phospho-GSK3β Ser9 expression. The highest level of diversity was at 4 weeks postoperative. Therefore, repeated IR can severely damage the hippocampus and decrease the learning and memory functions in mice. Changes in the Akt and GSK3β protein activity were involved in the IR process. LiCl treatment exerted a neuroprotective effect on learning and memory by potentiating the Akt/GSK3β cell-signaling pathway. Topics: Animals; Apoptosis; Brain Ischemia; CA1 Region, Hippocampal; Disease Models, Animal; Lithium Chloride; Male; Maze Learning; Memory; Mice, Inbred C57BL; Neurons; Neuroprotective Agents; Random Allocation; Reperfusion Injury; Swimming; Time Factors; Treatment Outcome | 2015 |
Lithium chloride stimulates PLP and MBP expression in oligodendrocytes via Wnt/β-catenin and Akt/CREB pathways.
Deciphering the molecular pathways involved in myelin gene expression is a major point of interest to better understand re/myelination processes. In this study, we investigated the role of Lithium Chloride (LiCl), a drug largely used for the treatment of neurological disorders, on the two major central myelin gene expression (PLP and MBP) in mouse oligodendrocytes. We show that LiCl enhances the expression of both PLP and MBP, by increasing mRNA amount and promoter activities. We investigated whether Wnt/β-catenin and/or Akt/CREB pathways are modulated by LiCl to regulate myelin gene expression. We showed that β-catenin is required both for PLP and MBP basal promoter activities and for LiCl-induced myelin gene stimulation. Furthermore, while CREB functionality does not influence PLP expression, MBP promoter activity depends on Akt/CREB activation. Finally, we show that LiCl can stimulate oligodendrocyte morphological maturation, and promote remyelination after lysolecithin-induced demyelination of organotypic cerebellar slice cultures. Our data provide mechanistic evidences that Akt/CREB together with β-catenin participate in the transcriptional control of PLP and MBP exerted by LiCl. Therefore, the use of LiCl to balance between β-catenin and CREB effectors could be considered as an efficient remyelinating strategy. Topics: Animals; beta Catenin; Brain; Cell Line; Cells, Cultured; Cyclic AMP Response Element-Binding Protein; Demyelinating Diseases; Disease Models, Animal; Gene Expression; Lithium Chloride; Mice, Inbred C57BL; Mice, Transgenic; Myelin Basic Protein; Myelin Proteolipid Protein; Neuroprotective Agents; Oligodendroglia; Proto-Oncogene Proteins c-akt; RNA, Messenger; Signal Transduction; Tissue Culture Techniques; Wnt Proteins | 2015 |
Protection against Klebsiella pneumoniae using lithium chloride in an intragastric infection model.
Intragastric Klebsiella pneumoniae infections of mice can cause liver abscesses, necrosis of liver tissues, and bacteremia. Lithium chloride, a widely prescribed drug for bipolar mood disorder, has been reported to possess anti-inflammatory properties. Using an intragastric infection model, the effects of LiCl on K. pneumoniae infections were examined. Providing mice with drinking water containing LiCl immediately after infection protected them from K. pneumoniae-induced death and liver injuries, such as necrosis of liver tissues, as well as increasing blood levels of aspartate aminotransferase and alanine aminotransferase, in a dose-dependent manner. LiCl administered as late as 24 h postinfection still provided protection. Monitoring of the LiCl concentrations in the sera of K. pneumoniae-infected mice showed that approximately 0.33 mM LiCl was the most effective dose for protecting mice against infections, which is lower than the clinically toxic dose of LiCl. Surveys of bacterial counts and cytokine expression levels in LiCl-treated mice revealed that both were effectively inhibited in blood and liver tissues. Using in vitro assays, we found that LiCl (5 μM to 1 mM) did not directly interfere with the growth of K. pneumoniae but made K. pneumoniae cells lose the mucoid phenotype and become more susceptible to macrophage killing. Furthermore, low doses of LiCl also partially enhanced the bactericidal activity of macrophages. Taken together, these data suggest that LiCl is an alternative therapeutic agent for K. pneumoniae-induced liver infections. Topics: Animals; Cytokines; Disease Models, Animal; Dose-Response Relationship, Drug; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Klebsiella Infections; Klebsiella pneumoniae; Lithium Chloride; Liver Abscess; Macrophages; Male; Mice; Mice, Inbred C57BL | 2015 |
Subacute administration of fluoxetine prevents short-term brain hypometabolism and reduces brain damage markers induced by the lithium-pilocarpine model of epilepsy in rats.
The role of serotonin (5-hydroxytryptamine; 5-HT) in epileptogenesis still remains controversial. In this regard, it has been reported that serotonergic drugs can alter epileptogenesis in opposite ways. The main objective of this work was to investigate the effect of the selective 5-HT selective reuptake inhibitor (SSRI) fluoxetine administered subacutely (10mg/kg/day×7 days) on the eventual metabolic impairment induced by the lithium-pilocarpine model of epilepsy in rats. In vivo 2-deoxy-2-[(18)F]fluoro-d-glucose ([(18)F] FDG) positron emission tomography (PET) was performed to assess the brain glucose metabolic activity on days 3 and 30 after the insult. In addition, at the end of the experiment (day 33), several histochemical and neurochemical assessments were performed for checking the neuronal functioning and integrity. Three days after the insult, a marked reduction of [(18)F] FDG uptake (about 30% according to the brain region) was found in all brain areas studied. When evaluated on day 30, although a hypometabolism tendency was observed, no statistically significant reduction was present in any region analyzed. In addition, lithium-pilocarpine administration was associated with medium-term hippocampal and cortical damage, since it induced neurodegeneration, glial activation and augmented caspase-9 expression. Regarding the effect of fluoxetine, subacute treatment with this SSRI did not significantly reduce the mortality rate observed after pilocarpine-induced seizures. However, fluoxetine did prevent not only the short-term metabolic impairment, but also the aforementioned signs of neuronal damage in surviving animals to lithium-pilocarpine protocol. Finally, fluoxetine increased the density of GABAA receptor both at the level of the dentate gyrus and CA1-CA2 regions in pilocarpine-treated animals. Overall, our data suggest a protective role for fluoxetine against pilocarpine-induced brain damage. Moreover, this action may be associated with an increase of GABAA receptor expression in hippocampus. Topics: Animals; Apoptosis; Astrocytes; Brain; Caspase 3; Disease Models, Animal; Epilepsy; Fluoxetine; Glucose; Hippocampus; Lithium Chloride; Male; Pilocarpine; Positron-Emission Tomography; Rats; Rats, Sprague-Dawley; Receptors, GABA-A; Selective Serotonin Reuptake Inhibitors; Survival Analysis | 2015 |
Effective termination of status epilepticus by rational polypharmacy in the lithium-pilocarpine model in rats: Window of opportunity to prevent epilepsy and prediction of epilepsy by biomarkers.
The pilocarpine rat model, in which status epilepticus (SE) leads to epilepsy with spontaneous recurrent seizures (SRS), is widely used to study the mechanisms of epileptogenesis and develop strategies for epilepsy prevention. SE is commonly interrupted after 30-90min by high-dose diazepam or other anticonvulsants to reduce mortality. It is widely believed that SE duration of 30-60min is sufficient to induce hippocampal damage and epilepsy. However, resistance to diazepam develops during SE, so that an SE that is longer than 30min is difficult to terminate, and SE typically recurs several hours after diazepam, thus forming a bias for studies on epileptogenesis or antiepileptogenesis. We developed a drug cocktail, consisting of diazepam, phenobarbital, and scopolamine that allows complete and persistent SE termination in the lithium-pilocarpine model. A number of novel findings were obtained with this cocktail. (a) In contrast to previous reports with incomplete SE suppression, a SE of 60min duration did not induce epilepsy, whereas epilepsy with SRS developed after 90 or 120min SE; (b) by comparing groups of rats with 60 and 90min of SE, development of epilepsy could be predicted by behavioral hyperexcitability and decrease in seizure threshold, indicating that these read-outs are suited as biomarkers of epileptogenesis; (c) CA1 damage was prevented by the cocktail, but rats exhibited cell loss in the dentate hilus, which was related to development of epilepsy. These data demonstrate that the duration of SE needed for induction of epileptogenesis in this model is longer than previously thought. Topics: Animals; Anticonvulsants; Diazepam; Disease Models, Animal; Electrodes, Implanted; Electroencephalography; Female; Hippocampus; Lithium Chloride; Neurons; Phenobarbital; Pilocarpine; Polypharmacy; Rats, Sprague-Dawley; Scopolamine; Seizures; Status Epilepticus; Time Factors; Treatment Outcome | 2015 |
Activation of the Canonical Wnt Signaling Pathway Induces Cementum Regeneration.
Canonical Wnt signaling is important in tooth development but it is unclear whether it can induce cementogenesis and promote the regeneration of periodontal tissues lost because of disease. Therefore, the aim of this study is to investigate the influence of canonical Wnt signaling enhancers on human periodontal ligament cell (hPDLCs) cementogenic differentiation in vitro and cementum repair in a rat periodontal defect model. Canonical Wnt signaling was induced by (1) local injection of lithium chloride; (2) local injection of sclerostin antibody; and (3) local injection of a lentiviral construct overexpressing β-catenin. The results showed that the local activation of canonical Wnt signaling resulted in significant new cellular cementum deposition and the formation of well-organized periodontal ligament fibers, which was absent in the control group. In vitro experiments using hPDLCs showed that the Wnt signaling pathway activators significantly increased mineralization, alkaline phosphatase (ALP) activity, and gene and protein expression of the bone and cementum markers osteocalcin (OCN), osteopontin (OPN), cementum protein 1 (CEMP1), and cementum attachment protein (CAP). Our results show that the activation of the canonical Wnt signaling pathway can induce in vivo cementum regeneration and in vitro cementogenic differentiation of hPDLCs. Topics: Animals; Antibodies; beta Catenin; Biomarkers; Cell Differentiation; Cementogenesis; Dental Cementum; Disease Models, Animal; Humans; Lithium Chloride; Male; Osteogenesis; Periodontium; Rats, Inbred Lew; Regeneration; Wnt Signaling Pathway; Wnt3A Protein; Wound Healing; X-Ray Microtomography | 2015 |
Microglial activation enhances associative taste memory through purinergic modulation of glutamatergic neurotransmission.
The cerebral innate immune system is able to modulate brain functioning and cognitive processes. During activation of the cerebral innate immune system, inflammatory factors produced by microglia, such as cytokines and adenosine triphosphate (ATP), have been directly linked to modulation of glutamatergic system on one hand and learning and memory functions on the other hand. However, the cellular mechanisms by which microglial activation modulates cognitive processes are still unclear. Here, we used taste memory tasks, highly dependent on glutamatergic transmission in the insular cortex, to investigate the behavioral and cellular impacts of an inflammation restricted to this cortical area in rats. We first show that intrainsular infusion of the endotoxin lipopolysaccharide induces a local inflammation and increases glutamatergic AMPA, but not NMDA, receptor expression at the synaptic level. This cortical inflammation also enhances associative, but not incidental, taste memory through increase of glutamatergic AMPA receptor trafficking. Moreover, we demonstrate that ATP, but not proinflammatory cytokines, is responsible for inflammation-induced enhancement of both associative taste memory and AMPA receptor expression in insular cortex. In conclusion, we propose that inflammation restricted to the insular cortex enhances associative taste memory through a purinergic-dependent increase of glutamatergic AMPA receptor expression at the synapse. Topics: Animals; Association Learning; Corticosterone; Cytokines; Disease Models, Animal; Encephalitis; Glutamic Acid; Lipopolysaccharides; Lithium Chloride; Male; Memory; Microglia; Protein Transport; Purinergic Agents; Rats; Rats, Wistar; Receptors, AMPA; Receptors, N-Methyl-D-Aspartate; Synaptic Transmission; Taste | 2015 |
The role of ubiquitin/Nedd4-2 in the pathogenesis of mesial temporal lobe epilepsy.
Although the pathogenesis and epileptogenesis of mesial temporal lobe epilepsy (MTLE) have been studied for years, many questions remain. The ubiquitin-proteasome system (UPS) is one factor that might regulate ion channels, inflammation and neuron excitability. Nedd4-2 is an E3 ubiquitin ligase linked with ion channels and synaptic vesicle recycling. Here, we explore the role of the UPS and its E3 ligase Nedd4-2 in the pathogenesis of MTLE. Our western blot results revealed that ubiquitin and Nedd4-2 were expressed differentially in different stages of MTLE. Co-immunoprecipitation and double immunostaining results indicated that Nedd4-2 was the substrate protein of ubiquitin both in vivo and in vitro. Inhibition of the UPS aggravated the epileptogenesis of MTLE, causing early and frequent spontaneous seizures, more obvious neuron loss and aberrant mossy fiber sprouting. Inhibition of ubiquitin also enhanced the activation of Nedd4-2, and switched ion channel α-ENaC downstream. Our study is the first to report that the UPS participates in the pathogenesis of MTLE, inhibition of UPS could aggravate the epileptogenesis, and that Nedd4-2 is a critical E3 ligase involved in this process. Topics: Adenosine Monophosphate; Analysis of Variance; Animals; Animals, Newborn; Antimanic Agents; Cells, Cultured; Cysteine Proteinase Inhibitors; Disease Models, Animal; Endosomal Sorting Complexes Required for Transport; Epilepsy, Temporal Lobe; Female; Gene Expression Regulation; Hippocampus; Immunoprecipitation; Leupeptins; Lithium Chloride; Male; Muscarinic Agonists; Nedd4 Ubiquitin Protein Ligases; Neurons; Pilocarpine; Rats, Sprague-Dawley; RNA, Small Interfering; Time Factors; Transfection; Ubiquitin; Ubiquitin-Protein Ligases; Ubiquitins | 2015 |
Prophylactic lithium alleviates splenectomy-induced cognitive dysfunction possibly by inhibiting hippocampal TLR4 activation in aged rats.
Though the pathogenesis of postoperative cognitive dysfunction (POCD) remains unclear, evidence is accumulating for a pivotal role of neuroinflammation in the disease process. Advanced age and severe surgical trauma are two main risk factors for POCD. Lithium, a neuroprotective agent, can alleviate peripheral surgery-induced memory impairment in aged rats. The results of in vivo and in vitro experiments also showed that toll like receptor 4 (TLR4) was associated with the occurrence and development of neuroinflammation and POCD. So we hypothesized that inhibition of TLR4 signaling in the hippocampus maybe involved in the protective effects of prophylactic lithium on the occurrence of inflammation and POCD. In the present study, we incubated BV-2 microglia with 1μg/ml lipopolysaccharide (LPS) to mimic neuroinflammation in vitro. We found that pretreatment with 10mM of lithium or 100nM of TLR4 siRNA could inhibit the tumor necrosis factor (TNF)-α and TLR4 mRNA expression induced by LPS in BV-2 microglia. Furthermore, combination of prophylactic lithium and TLR4 siRNA even decreased their mRNA expression to the baseline levels, which showed that TLR4 signaling may be vital in protective effects of prophylactic lithium on neuroinflammation. So we further undergone the in vivo experiment. Then, we firstly demonstrated that prophylactic 2mM/kg of lithium alleviated splenectomy-induced cognitive impairments, decreased splenectomy-associated systemic, central, and hippocampal TNF-α and interleukin (IL)-1β expression and reduced the increase of CD11b(+) area in hippocampal CA1 region caused by the surgery. Then, we also found that splenectomy merely increased hippocampal TLR2 and TLR4 mRNA levels in aged rats. At last, we confirmed that prophylactic lithium reduced the increased levels of hippocampal TLR4/NF-κB induced by splenectomy. Taken together, these results demonstrate that TLR4 signaling inactivation may contribute to the protective effects of prophylactic lithium on the occurrence of POCD by inhibiting systemic inflammation and especially neuroinflammation. Topics: Aging; Animals; CD11b Antigen; Cell Line; Cognition Disorders; Disease Models, Animal; Interleukin-1beta; Lipopolysaccharides; Lithium Chloride; Male; Mice; Microglia; Neuroimmunomodulation; NF-kappa B; Nootropic Agents; Random Allocation; Rats, Sprague-Dawley; RNA, Messenger; RNA, Small Interfering; Splenectomy; Toll-Like Receptor 2; Toll-Like Receptor 4; Tumor Necrosis Factor-alpha | 2015 |
Introducing Female Black Swiss Mice: Minimal Effects of Sex in a Strain-Specific Battery of Tests for Mania-Like Behavior and Response to Lithium.
Black Swiss (BS) mice were shown to be an advantageous strain to model behavioral domains of mania, but to date only male mice were tested, whereas bipolar disorder (BPD) is equally prevalent in women and men. This study was therefore designed to examine the possibility of using both male and female BS mice in future studies. Groups of male and female BS mice were compared with each other, with or without lithium treatment, in tests for domains of mania-like behavior including activity in an open field, sweet solution preference, elevated plus maze, forced swim and amphetamine-induced hyperactivity. The results indicate mostly a similarity between female and male BS mice, both naïve and after chronic lithium treatment. The results are discussed in the context of the deficiency in utilizing female mice in animal models research and suggest that both male and female BS mice can be used to model domains of mania-like behavior. Topics: Amphetamine; Animals; Antipsychotic Agents; Behavior, Animal; Bipolar Disorder; Disease Models, Animal; Female; Lithium Chloride; Male; Mice; Species Specificity | 2015 |
Preclinical validation and imaging of Wnt-induced repair in human 3D lung tissue cultures.
Chronic obstructive pulmonary disease (COPD) is characterised by a progressive loss of lung tissue. Inducing repair processes within the adult diseased lung is of major interest and Wnt/β-catenin signalling represents a promising target for lung repair. However, the translation of novel therapeutic targets from model systems into clinical use remains a major challenge.We generated murine and patient-derived three-dimensional (3D) ex vivo lung tissue cultures (LTCs), which closely mimic the 3D lung microenvironment in vivo. Using two well-known glycogen synthase kinase-3β inhibitors, lithium chloride (LiCl) and CHIR 99021 (CT), we determined Wnt/β-catenin-driven lung repair processes in high spatiotemporal resolution using quantitative PCR, Western blotting, ELISA, (immuno)histological assessment, and four-dimensional confocal live tissue imaging.Viable 3D-LTCs exhibited preserved lung structure and function for up to 5 days. We demonstrate successful Wnt/β-catenin signal activation in murine and patient-derived 3D-LTCs from COPD patients. Wnt/β-catenin signalling led to increased alveolar epithelial cell marker expression, decreased matrix metalloproteinase-12 expression, as well as altered macrophage activity and elastin remodelling. Importantly, induction of surfactant protein C significantly correlated with disease stage (per cent predicted forced expiratory volume in 1 s) in patient-derived 3D-LTCs.Patient-derived 3D-LTCs represent a valuable tool to analyse potential targets and drugs for lung repair. Enhanced Wnt/β-catenin signalling attenuated pathological features of patient-derived COPD 3D-LTCs. Topics: Adult; Aged; Animals; beta Catenin; Cells, Cultured; Disease Models, Animal; Emphysema; Enzyme-Linked Immunosorbent Assay; Epithelial Cells; Female; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Humans; Lithium Chloride; Lung; Macrophages, Alveolar; Male; Mice; Mice, Inbred C57BL; Microscopy, Confocal; Middle Aged; Pulmonary Disease, Chronic Obstructive; Pyridines; Pyrimidines; Signal Transduction; Swine; Wnt Proteins; Wound Healing | 2015 |
Synergy between cannabidiol, cannabidiolic acid, and Δ⁹-tetrahydrocannabinol in the regulation of emesis in the Suncus murinus (house musk shrew).
Smoked marijuana contains over 100 different cannabinoids, including the psychoactive compound Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD). THC, CBD, and its acidic precursor, cannabidiolic acid (CBDA), have all been shown to have antiemetic properties in the Suncus murinus (S. murinus; house musk shrew). Here we show that when subthreshold antiemetic doses of CBD (2.5 mg/kg ip) or CBDA (0.05 mg/kg ip) are combined with a subthreshold antiemetic dose of THC (1 mg/kg ip) in the S. murinus, both lithium-chloride-induced vomiting and abdominal retching are dramatically suppressed. These results suggest that combined effects of these compounds may lead to better control of vomiting with fewer side effects. Topics: Animals; Antiemetics; Cannabidiol; Cannabinoids; Disease Models, Animal; Dronabinol; Drug Therapy, Combination; Female; Lithium Chloride; Male; Shrews; Vomiting | 2015 |
Lithium chloride administration prevents spatial learning and memory impairment in repeated cerebral ischemia-reperfusion mice by depressing apoptosis and increasing BDNF expression in hippocampus.
Lithium has been reported to have neuroprotective effects, but the preventive and treated role on cognition impairment and the underlying mechanisms have not been determined. In the present study, C57Bl/6 mice were subjected to repeated bilateral common carotid artery occlusion to induce the learning and memory deficits. 2 mmol/kg or 5 mmol/kg of lithium chloride (LiCl) was injected intraperitoneally per day before (for 7 days) or post (for 28 days) the operation. This repeated cerebral ischemia-reperfusion (IR) induced dynamic overexpression of ratio of Bcl-2/Bax and BDNF in hippocampus of mice. LiCl pretreatment and treatment significantly decreased the escape latency and increased the percentage of time that the mice spent in the target quadrant in Morris water maze. 2 mmol/kg LiCl evidently reversed the morphologic changes, up-regulated the survival neuron count and increased the BDNF gene and protein expression. 5 mmol/kg pre-LiCl significantly increased IR-stimulated reduce of Bcl-2/Bax and p-CREB/CREB. These results described suggest that pre-Li and Li treatment may induce a pronounced prevention on cognitive impairment. These effects may relay on the inhibition of apoptosis and increasing BDNF and p-CREB expression. Topics: Animals; Apoptosis; bcl-2-Associated X Protein; Brain Ischemia; Brain-Derived Neurotrophic Factor; Carotid Artery Diseases; Cell Survival; Cyclic AMP Response Element-Binding Protein; Disease Models, Animal; Hippocampus; Learning Disabilities; Lithium Chloride; Male; Maze Learning; Memory Disorders; Mice, Inbred C57BL; Neurons; Nootropic Agents; Proto-Oncogene Proteins c-bcl-2; Random Allocation; Reperfusion Injury; Spatial Memory | 2015 |
Notch pathway is activated in cell culture and mouse models of mutant SOD1-related familial amyotrophic lateral sclerosis, with suppression of its activation as an additional mechanism of neuroprotection for lithium and valproate.
Amyotrophic lateral sclerosis (ALS) is an idiopathic and lethal neurodegenerative disease that currently has no effective treatment. A recent study found that the Notch signaling pathway was up-regulated in a TAR DNA-binding protein-43 (TDP-43) Drosophila model of ALS. Notch signaling acts as a master regulator in the central nervous system. However, the mechanisms by which Notch participates in the pathogenesis of ALS have not been completely elucidated. Recent studies have shown that the mood stabilizers lithium and valproic acid (VPA) are able to regulate Notch signaling. Our study sought to confirm the relationship between the Notch pathway and ALS and whether the Notch pathway contributes to the neuroprotective effects of lithium and VPA in ALS. We found that the Notch pathway was activated in in vitro and in vivo models of ALS, and suppression of Notch activation with a Notch signaling inhibitor, N-[N-(3,5-difluorophenacetyl-L-alanyl)]-S-phenylglycine t-butyl ester (DAPT) and Notch1 siRNA significantly reduced neuronal apoptotic signaling, as evidenced by the up-regulation of Bcl-2 as well as the down-regulation of Bax and cytochrome c. We also found that lithium and VPA suppressed the Notch activation associated with the superoxide dismutase-1 (SOD1) mutation, and the combination of lithium and VPA produced a more robust effect than either agent alone. Our findings indicate that the Notch pathway plays a critical role in ALS, and the neuroprotective effects of lithium and VPA against mutant SOD1-mediated neuronal damage are at least partially dependent on their suppression of Notch activation. Topics: Amyotrophic Lateral Sclerosis; Animals; Cells, Cultured; Disease Models, Animal; Embryo, Mammalian; Gene Expression Regulation; Humans; Lithium Chloride; Mice; Mice, Transgenic; Motor Neurons; Neuroprotective Agents; Receptors, Notch; RNA, Small Interfering; Signal Transduction; Spinal Cord; Superoxide Dismutase; Transfection; Valproic Acid | 2015 |
Mice heterozygous for cathepsin D deficiency exhibit mania-related behavior and stress-induced depression.
Mutations in cathepsin D (CTSD), an aspartic protease in the endosomal-lysosomal system, underlie congenital neuronal ceroid-lipofuscinosis (cNCL, also known as CLN10), a devastating neurodegenerative disease. CLN10 patients die within the first few days of life, and in the few patients who live into adulthood psychopathological symptoms have not been reported. Extensive neuropathology and altered neurotransmission have been reported in CTSD-deficient mice; however signs of neuropsychiatric behavior in these mice are not well characterized due to the severe movement disorder and premature death of the animal. In the present study, we show that heterozygous CTSD-deficient (CTSD HET) mice display an overall behavioral profile that is similar to human mania, including hyperlocomotion, d-amphetamine-induced hyperactivity, sleep-disturbance, and reduced anxiety-like behavior. However, under stressful conditions CTSD HET mice manifest depressive-like behavior, including anhedonia, behavioral despair, and enhanced learned helplessness. Chronic administration of lithium chloride or valproic acid, two clinically effective mood stabilizers, reverses the majority of these behavioral abnormalities. In addition, CTSD HET mice display stress-induced hypersecretion of corticosterone. These findings suggest an important role for CTSD in the regulation of mood stabilization. Topics: Adaptation, Ocular; Animals; Antidepressive Agents; Bipolar Disorder; Cathepsin D; Corticosterone; Depression; Dextroamphetamine; Disease Models, Animal; Exploratory Behavior; Female; Food Preferences; Hyperkinesis; Lithium Chloride; Male; Maze Learning; Mice; Mice, Inbred C57BL; Mice, Knockout; Neuronal Ceroid-Lipofuscinoses; Sleep Wake Disorders; Swimming; Valproic Acid | 2015 |
Ribosomal Protein Mutations Result in Constitutive p53 Protein Degradation through Impairment of the AKT Pathway.
Mutations in ribosomal protein (RP) genes can result in the loss of erythrocyte progenitor cells and cause severe anemia. This is seen in patients with Diamond-Blackfan anemia (DBA), a pure red cell aplasia and bone marrow failure syndrome that is almost exclusively linked to RP gene haploinsufficiency. While the mechanisms underlying the cytopenia phenotype of patients with these mutations are not completely understood, it is believed that stabilization of the p53 tumor suppressor protein may induce apoptosis in the progenitor cells. In stark contrast, tumor cells from zebrafish with RP gene haploinsufficiency are unable to stabilize p53 even when exposed to acute DNA damage despite transcribing wild type p53 normally. In this work we demonstrate that p53 has a limited role in eliciting the anemia phenotype of zebrafish models of DBA. In fact, we find that RP-deficient embryos exhibit the same normal p53 transcription, absence of p53 protein, and impaired p53 response to DNA damage as RP haploinsufficient tumor cells. Recently we reported that RP mutations suppress activity of the AKT pathway, and we show here that this suppression results in proteasomal degradation of p53. By re-activating the AKT pathway or by inhibiting GSK-3, a downstream modifier that normally represses AKT signaling, we are able to restore the stabilization of p53. Our work indicates that the anemia phenotype of zebrafish models of DBA is dependent on factors other than p53, and may hold clinical significance for both DBA and the increasing number of cancers revealing spontaneous mutations in RP genes. Topics: Anemia, Diamond-Blackfan; Animals; Animals, Genetically Modified; Apoptosis; Disease Models, Animal; DNA Damage; DNA Repair; Glycogen Synthase Kinase 3; Haploinsufficiency; Insulin; Leupeptins; Lithium Chloride; Morpholinos; Proteasome Endopeptidase Complex; Proteasome Inhibitors; Proto-Oncogene Proteins c-akt; Ribosomal Proteins; RNA, Messenger; Signal Transduction; Transcription, Genetic; Tumor Suppressor Protein p53; Zebrafish; Zebrafish Proteins | 2015 |
Hyperthermia aggravates status epilepticus-induced epileptogenesis and neuronal loss in immature rats.
This study tightly controlled seizure duration and severity during status epilepticus (SE) in postnatal day 10 (P10) rats, in order to isolate hyperthermia as the main variable and to study its consequences. Body temperature was maintained at 39 ± 1 °C in hyperthermic SE rats (HT+SE) or at 35 ± 1 °C in normothermic SE animals (NT+SE) during 30 min of SE, which was induced by lithium-pilocarpine (3 mEq/kg, 60 mg/kg) and terminated by diazepam and cooling to NT. All video/EEG measures of SE severity were similar between HT+SE and NT+SE pups. At 24h, neuronal injury was present in the amygdala in the HT+SE group only, and was far more severe in the hippocampus in HT+SE than NT+SE pups. Separate groups of animals were monitored four months later for spontaneous recurrent seizures (SRS). Only HT+SE animals developed convulsive SRS. Both HT+SE and NT+SE animals developed electrographic SRS (83% vs. 55%), but SRS frequency and severity were higher in hyperthermic animals (12.5 ± 3.5 vs. 4.2 ± 2.0 SRS/day). The density of hilar neurons was lower, thickness of the amygdala and perirhinal cortex was reduced, and lateral ventricles were enlarged in HT+SE over NT+SE littermates and HT/NT controls. In this model, hyperthermia greatly increased the epileptogenicity of SE and its neuropathological sequelae. Topics: Adjuvants, Immunologic; Animals; Animals, Newborn; Anticonvulsants; Apoptosis; Brain; Cell Death; Diazepam; Disease Models, Animal; Hyperthermia, Induced; Lithium Chloride; Male; Muscarinic Agonists; Nerve Degeneration; Neurons; Neuropil; Pilocarpine; Rats; Rats, Wistar; Status Epilepticus; Time Factors | 2015 |
Endoplasmic reticulum (ER) stress protein responses in relation to spatio-temporal dynamics of astroglial responses to status epilepticus in rats.
In the present study, we investigated whether endoplasmic reticulum (ER) stress is associated with neuronal- and astroglial-death in the hippocampus using LiCl-pilocarpine-induced status epilepticus (SE) rat model. Glucose-related protein (GRP) 78 and protein disulfide isomerase (PDI) expressions were transiently increased in CA1 neurons and dentate granule cells, and subsequently decreased in these cells following SE. GRP94 and calnexin (CNX) expression was gradually reduced in CA1 neurons, not in dentate granule cells. Phospho-protein kinase RNA (PKR)-like ER kinase (pPERK), phospho-eukaryotic initiation factor 2α (peIF2A) and CCAAT/enhancer-binding protein homologous protein (CHOP) immunoreactivities were observed in 17%, 12% and 7% of degenerating CA1 neurons, respectively. GRP 78 and PDI expressions were also up-regulated in reactive astrocytes within the CA1-3 regions. In the molecular layer of the dentate gyrus, PDI-positive astrocytes showed TUNEL signal, nuclear apoptosis inducing factor translocation and pPERK/peIF2A/CHOP immunoreactivities. Four weeks after SE, clasmatodendritic astrocytes showed pPERK peIF2A and CNX immunoreactivities without CHOP expression. These findings indicate that SE-induced ER stress may be associated with astroglial apoptosis and autophagic astroglial death in the regional-specific pattern. Topics: Animals; Apoptosis Inducing Factor; Astrocytes; Calnexin; Disease Models, Animal; Endoplasmic Reticulum Chaperone BiP; Endoplasmic Reticulum Stress; Hippocampus; HSP70 Heat-Shock Proteins; In Situ Nick-End Labeling; Lithium Chloride; Male; Membrane Proteins; Nerve Tissue Proteins; Pilocarpine; Rats; Rats, Sprague-Dawley; Status Epilepticus; Time Factors; Transcription Factor CHOP; Up-Regulation | 2015 |
Effect of combined doses of Δ(9)-tetrahydrocannabinol (THC) and cannabidiolic acid (CBDA) on acute and anticipatory nausea using rat (Sprague- Dawley) models of conditioned gaping.
Δ(9)-Tetrahydrocannabinol (THC) and cannabidiolic acid (CBDA) found in cannabis both reduce the distressing symptom of nausea, but their combined effects are not understood.. The potential of combined doses of THC and CBDA to reduce acute nausea and anticipatory nausea in rodent models was assessed.. For acute nausea, the potential of cannabinoid pretreatment(s) to reduce LiCl-induced nausea paired with saccharin was evaluated in a subsequent drug free taste reactivity test, followed by a taste avoidance test. For anticipatory nausea, the potential of the cannabinoid pretreatment(s) to reduce the expression of LiCl-induced contextually elicited conditioned gaping was evaluated.. Combined subthreshold doses of THC (0.01 and 0.1 mg/kg) and CBDA (0.01 and 0.1 μg/kg) reduced acute nausea. Higher doses of THC (1.0, 10 mg/kg) or CBDA (1.0, 10 μg/kg) alone, as well as these combined doses also reduced acute nausea. THC (10 mg/kg) interfered with conditioned taste avoidance, an effect attenuated by CBDA (10 μg/kg). On the other hand, combined subthreshold doses of THC (0.01 and 0.1 mg/kg) and CBDA (0.01 and 0.1 μg/kg) did not suppress contextually elicited conditioned gaping in a test for anticipatory nausea. However, higher doses of THC (1.0, 10 mg/kg) or CBDA (1.0, 10 μg/kg) alone, as well as these combined doses, also reduced anticipatory nausea. Only at the highest dose (10 mg/kg) did THC impair locomotor activity, but CBDA did not at any dose.. Combined subthreshold doses of THC:CBDA are particularly effective as a treatment for acute nausea. At higher doses, CBDA may attenuate THC-induced interference with learning. Topics: Animals; Antiemetics; Cannabinoids; Conditioning, Psychological; Disease Models, Animal; Dronabinol; Drug Therapy, Combination; Lithium Chloride; Male; Nausea; Rats; Rats, Sprague-Dawley; Saccharin | 2015 |
Glycogen synthase kinase-3 inhibitors reverse deficits in long-term potentiation and cognition in fragile X mice.
Identifying feasible therapeutic interventions is crucial for ameliorating the intellectual disability and other afflictions of fragile X syndrome (FXS), the most common inherited cause of intellectual disability and autism. Hippocampal glycogen synthase kinase-3 (GSK3) is hyperactive in the mouse model of FXS (FX mice), and hyperactive GSK3 promotes locomotor hyperactivity and audiogenic seizure susceptibility in FX mice, raising the possibility that specific GSK3 inhibitors may improve cognitive processes.. We tested if specific GSK3 inhibitors improve deficits in N-methyl-D-aspartate receptor-dependent long-term potentiation at medial perforant path synapses onto dentate granule cells and dentate gyrus-dependent cognitive behavioral tasks.. GSK3 inhibitors completely rescued deficits in long-term potentiation at medial perforant path-dentate granule cells synapses in FX mice. Furthermore, synaptosomes from the dentate gyrus of FX mice displayed decreased inhibitory serine-phosphorylation of GSK3β compared with wild-type littermates. The potential therapeutic utility of GSK3 inhibitors was further tested on dentate gyrus-dependent cognitive behaviors. In vivo administration of GSK3 inhibitors completely reversed impairments in several cognitive tasks in FX mice, including novel object detection, coordinate and categorical spatial processing, and temporal ordering for visual objects.. These findings establish that synaptic plasticity and cognitive deficits in FX mice can be improved by intervention with inhibitors of GSK3, which may prove therapeutically beneficial in FXS. Topics: Animals; Cognition; Cognition Disorders; Disease Models, Animal; Disks Large Homolog 4 Protein; Electric Stimulation; Excitatory Amino Acid Antagonists; Fragile X Mental Retardation Protein; Fragile X Syndrome; Glycogen Synthase Kinase 3; Guanylate Kinases; Hippocampus; In Vitro Techniques; Lithium Chloride; Long-Term Potentiation; Membrane Proteins; Mice; Mice, Transgenic; Patch-Clamp Techniques; Protein Kinase Inhibitors; Synapses | 2014 |
Behavioral impairments in rats with chronic epilepsy suggest comorbidity between epilepsy and attention deficit/hyperactivity disorder.
Attention deficit/hyperactivity disorder (ADHD) is encountered among patients with epilepsy at a significantly higher rate than in the general population. Mechanisms of epilepsy-ADHD comorbidity remain largely unknown. We investigated whether a model of chronic epilepsy in rats produces signs of ADHD, and thus, whether it can be used for studying mechanisms of this comorbidity. Epilepsy was induced in male Wistar rats via pilocarpine status epilepticus. Half of the animals exhibited chronic ADHD-like abnormalities, particularly increased impulsivity and diminished attention in the lateralized reaction-time task. These impairments correlated with the suppressed noradrenergic transmission in locus coeruleus outputs. The other half of animals exhibited depressive behavior in the forced swimming test congruently with the diminished serotonergic transmission in raphe nucleus outputs. Attention deficit/hyperactivity disorder and depressive behavior appeared mutually exclusive. Therefore, the pilocarpine model of epilepsy affords a system for reproducing and studying mechanisms of comorbidity between epilepsy and both ADHD and/or depression. Topics: Animals; Attention Deficit Disorder with Hyperactivity; Behavioral Symptoms; Brain; Chronic Disease; Compulsive Behavior; Convulsants; Disease Models, Animal; Epilepsy; Functional Laterality; Immobility Response, Tonic; Lithium Chloride; Male; Photic Stimulation; Pilocarpine; Rats; Rats, Wistar; Reaction Time; Swimming | 2014 |
Serotonin 1A receptor inhibits the status epilepticus induced by lithium-pilocarpine in rats.
Status epilepticus (SE) is a life-threatening neurological emergency associated with a high mortality rate. The serotonin 1A (5-HT1A) receptor is a possible target for the treatment of SE, but its role in animal models and the precise area of brain involved remain controversial. The hippocampus is a candidate site due to its key role in the development of SE and the existence of a high density of 5-HT1A receptors. Therefore, we investigated the effects of subcutaneous and intrahippocampal activation of 5-HT1A receptors in lithium-pilocarpine-induced SE, and tested whether the hippocampus is a true effector site. We developed SE in male Sprague-Dawley rats by giving lithium chloride (LiCl; 3 meq/kg, i.p.) 22-24 h prior to pilocarpine (25 mg/kg, i.p.), and found that 8-OH-DPAT, a 5-HT1A receptor agonist administered subcutaneously (s.c.) at 0.5 or 1.0 mg/kg 1 h before pilocarpine injection increased the latency to the first epileptiform spikes, the electrographic SE, and the behavioral generalized seizures (GS), while reducing the total EEG seizure time (P <0.01). The duration of GS was shortened only by 1.0 mg/kg 8-OH-DPAT s.c. (P <0.05). All these effects were inhibited by combined administration of WAY-100635 (1.0 mg/kg, s.c.) (P <0.05), an antagonist of the 5-HT1A receptor, but WAY-100635 alone and low doses of 8-OHDPAT (0.01 and 0.1 mg/kg) did not alter seizure activity. Furthermore, intrahippocampal 8-OH-DPAT only shortened the GS duration (P <0.05). These findings imply that the 5-HT1A receptor is a promising therapeutic target against the generation and propagation of SE, and hippocampal receptors are involved in reducing the seizure severity. Topics: 8-Hydroxy-2-(di-n-propylamino)tetralin; Action Potentials; Analysis of Variance; Animals; Disease Models, Animal; Dose-Response Relationship, Drug; Electroencephalography; Hippocampus; Lithium Chloride; Male; Muscarinic Agonists; Pilocarpine; Piperazines; Pyridines; Rats; Rats, Sprague-Dawley; Reaction Time; Receptor, Serotonin, 5-HT1A; Serotonin Antagonists; Status Epilepticus; Time Factors | 2014 |
Dopamine in the dorsal hippocampus impairs the late consolidation of cocaine-associated memory.
Cocaine is thought to be addictive because it elevates dopamine levels in the striatum, reinforcing drug-seeking habits. Cocaine also elevates dopamine levels in the hippocampus, a structure involved in contextual conditioning as well as in reward function. Hippocampal dopamine promotes the late phase of consolidation of an aversive step-down avoidance memory. Here, we examined the role of hippocampal dopamine function in the persistence of the conditioned increase in preference for a cocaine-associated compartment. Blocking dorsal hippocampal D1-type receptors (D1Rs) but not D2-type receptors (D2Rs) 12 h after a single training trial extended persistence of the normally short-lived memory; conversely, a general and a specific phospholipase C-coupled D1R agonist (but not a D2R or adenylyl cyclase-coupled D1R agonist) decreased the persistence of the normally long-lived memory established by three-trial training. These effects of D1 agents were opposite to those previously established in a step-down avoidance task, and were here also found to be opposite to those in a lithium chloride-conditioned avoidance task. After returning to normal following cocaine injection, dopamine levels in the dorsal hippocampus were found elevated again at the time when dopamine antagonists and agonists were effective: between 13 and 17 h after cocaine injection. These findings confirm that, long after the making of a cocaine-place association, hippocampal activity modulates memory consolidation for that association via a dopamine-dependent mechanism. They suggest a dynamic role for dorsal hippocampal dopamine in this late-phase memory consolidation and, unexpectedly, differential roles for late consolidation of memories for places that induce approach or withdrawal because of a drug association. Topics: Animals; Association Learning; Brain-Derived Neurotrophic Factor; Cocaine; Conditioning, Operant; Disease Models, Animal; Dopamine; Dopamine Agents; Dopamine Uptake Inhibitors; Dose-Response Relationship, Drug; Drug Administration Routes; Hippocampus; Lithium Chloride; Male; MAP Kinase Signaling System; Memory Disorders; Rats; Rats, Sprague-Dawley; Receptor, trkB; Time Factors | 2014 |
Effect of etanercept and lithium chloride on preventing secondary tissue damage in rats with experimental diffuse severe brain injury.
Studies in animals have provided key evidence that antagonizing TNF-α is a viable therapeutic strategy for diffuse severe brain injury. This study is planned to prevent post-traumatic secondary tissue damages in rat diffuse severe brain injury model, which is induced by alone or combined administration of Etanercept and lithium chloride (LiCl).. Male Sprague-Dawley rats were used in the current study. Rats were divided into 5 groups. Trauma was not induced and treatment was not applied to rats of Sham group. For rats of Trauma+Saline group, saline 0.9% was administered via intraperitoneal (i.p.) route at dose of 1 mg/100 g body weight 1 hour after trauma. For rats of Trauma+Etanercept group, Etanercept was administered via i.p. route at dose of 5 mg/kg body weight 1 hour after trauma. For rats of Trauma+LiCl group, LiCl was administered via i.p. route at dose of 50 mg/kg body weight 1 hour after trauma. For rats of Etanercept+LiCl group, Etanercept and LiCl were administered via i.p. route at dose of 5 mg/kg body weight and 50 mg/kg body weight, respectively, 1 hour after trauma. Serum glial fibrillary acidic protein (GFAP) and Tau levels were analyzed with ELISA. For analyses H&E, TUNEL, GFAP and TNF-α staining methods were used.. We demonstrate that Etanercept treatment reduced the TBI-induced brain tissues alteration, reduced the expression of TNF-α and improve edema and axonal swelling. We observed a significant decrease in TNF-α and GFAP positivity after LiCl was administered.. The findings obtained in this study suggest that the combination therapy with Etanercept and LiCl decreased neuronal degeneration and alleviated secondary tissue damage in post-traumatic period. Topics: Animals; Apoptosis; Astrocytes; Brain; Brain Injuries; Disease Models, Animal; Drug Therapy, Combination; Etanercept; Glial Fibrillary Acidic Protein; Immunoglobulin G; Lithium Chloride; Male; Neurons; Neuroprotective Agents; Rats, Sprague-Dawley; Receptors, Tumor Necrosis Factor; tau Proteins; Tumor Necrosis Factor-alpha | 2014 |
Lithium protects against cartilage degradation in osteoarthritis.
To determine the actions of lithium chloride (LiCl) on catabolic events in human articular chondrocytes, and the effects of LiCl on the progression and severity of cartilage degradation in interleukin-1β (IL-1β)-treated mouse knee joints and after surgical induction of osteoarthritis (OA) in a mouse model.. Human articular chondrocytes were treated with LiCl followed by IL-1β, and the expression levels of catabolic genes were determined by real-time polymerase chain reaction. To understand the mechanism by which LiCl affects catabolic events in articular chondrocytes after IL-1β treatment, the activation of NF-κB was determined using luciferase reporter assays, and the activities of MAPKs and the STAT-3 signaling pathway were determined by immunoblot analysis of total cell lysates. Cultures of mouse femoral head explants treated with IL-1β and a mouse model of surgically induced OA were used to determine the effects of LiCl on proteoglycan loss and cartilage degradation.. LiCl treatment resulted in decreased catabolic marker messenger RNA levels and activation of NF-κB, p38 MAPK, and STAT-3 signaling in IL-1β-treated articular chondrocytes. Furthermore, LiCl directly inhibited IL-6-stimulated activation of STAT-3 signaling. Consequently, the loss of proteoglycan and severity of cartilage destruction in LiCl-treated mouse knee joints 8 weeks after OA induction surgery or in LiCl-treated mouse femoral head explants after IL-1β treatment were markedly reduced compared to that in vehicle-treated joints or explants.. LiCl reduced catabolic events in IL-1β-treated human articular chondrocytes and attenuated the severity of cartilage destruction in IL-1β-treated mouse femoral head explants and in the knee joints of mice with surgically induced OA, acting via inhibition of the activities of the NF-κB, p38, and STAT-3 signaling pathways. Topics: Aged; Animals; Cartilage, Articular; Cells, Cultured; Chondrocytes; Disease Models, Animal; Disease Progression; Femur Head; Humans; Interleukin-1beta; Lithium Chloride; Male; Mice; Mice, Inbred C57BL; Middle Aged; NF-kappa B; Osteoarthritis; p38 Mitogen-Activated Protein Kinases; Proteoglycans; Severity of Illness Index; Signal Transduction; STAT3 Transcription Factor | 2014 |
Synchronous alteration pattern between serine-threonine kinase receptor-associated protein and Smad7 in pilocarpine-induced rats of epilepsy.
Recent studies have shown that transforming growth factor β (TGFβ) signaling participates in the epileptogenesis. Serine-threonine kinase receptor-associated protein (STRAP) and Smad7 synergize in the inhibition of the TGFβ signaling. The aim of the present study was to determine the expression pattern of STRAP and Smad7 in the hippocampus and temporal lobe cortex of pilocarpine-induced rats models of epilepsy.. Lithium chloride-pilocarpine-induced rats with status epilepticus (SE) were established. Total of 60 male Sprague-Dawley rats was used as control (n = 10), 24 h (n = 10), 72 h (n = 10), 1 week (n = 10), 1 month (n = 10), and 2 months (n = 10) after pilocarpine-induced SE, respectively. We detected the expression levels of STRAP and Smad7 in the hippocampus and temporal lobe cortex of rats at the aforementioned time points using western blotting and immunohistochemistry.. STRAP level was significantly decreased in 24 h, 72 h (acute stage), 1 week (latent stage), 1 month, 2 months (chronic stage), respectively, in the rat models compared with the control rats by using both western blotting and immunohistochemistry. Smad7 had similar reduced pattern as STRAP.. Our results indicate that STRAP and Smad7 proteins might be involved in the development of temporal lobe epilepsy. Topics: Adaptor Proteins, Signal Transducing; Animals; Blotting, Western; Chronic Disease; Disease Models, Animal; Epilepsy, Temporal Lobe; Gene Expression; Hippocampus; Immunohistochemistry; Lithium Chloride; Male; Pilocarpine; Rats; Rats, Sprague-Dawley; Smad7 Protein; Status Epilepticus; Temporal Lobe; Time Factors | 2014 |
Activation of brain indoleamine 2,3-dioxygenase contributes to epilepsy-associated depressive-like behavior in rats with chronic temporal lobe epilepsy.
Depression has most often been diagnosed in patients with temporal lobe epilepsy (TLE), but the mechanism underlying this association remains unclear. In this study, we report that indoleamine 2,3-dioxygenase 1 (IDO1), a rate-limiting enzyme in tryptophan metabolism, plays a key role in epilepsy-associated depressive-like behavior.. Rats which develop chronic epilepsy following pilocarpine status epilepticus exhibited a set of interictal disorders consistent with depressive-like behavior. Changes of depressive behavior were examined by taste preference test and forced swim test; brain IL-1β, IL-6 and IDO1 expression were quantified using real-time reverse transcriptase PCR; brain kynurenine/tryptophan and serotonin/tryptophan ratios were analyzed by liquid chromatography-mass spectrometry. Oral gavage of minocycline or subcutaneous injection of 1-methyltryptophan (1-MT) were used to inhibite IDO1 expression.. We observed the induction of IL-1β and IL-6 expression in rats with chronic TLE, which further induced the upregulation of IDO1 expression in the hippocampus. The upregulation of IDO1 subsequently increased the kynurenine/tryptophan ratio and decreased the serotonin/tryptophan ratio in the hippocampus, which contributed to epilepsy-associated depressive-like behavior. The blockade of IDO1 activation prevented the development of depressive-like behavior but failed to influence spontaneous seizures. This effect was achieved either indirectly, through the anti-inflammatory tetracycline derivative minocycline, or directly, through the IDO antagonist 1-MT, which normalizes kynurenine/tryptophan and serotonin/tryptophan ratios.. Brain IDO1 activity plays a key role in epileptic rats with epilepsy-associated depressive-like behavior. Topics: Animals; Chromatography, Liquid; Cytokines; Depression; Disease Models, Animal; Epilepsy, Temporal Lobe; Food Preferences; Gene Expression Regulation; Hippocampus; Indoleamine-Pyrrole 2,3,-Dioxygenase; Lithium Chloride; Male; Mass Spectrometry; Minocycline; Rats; Rats, Wistar; Statistics, Nonparametric; Time Factors; Tryptophan | 2014 |
GRK5 dysfunction accelerates tau hyperphosphorylation in APP (swe) mice through impaired cholinergic activity.
Recent studies have suggested that G-protein-coupled receptor kinase 5 (GRK5) deficiency plays a significant role in the pathogenesis of early Alzheimer's disease. Mild soluble β-amyloid accumulation can result in reduced membrane (functional) and elevated cytosolic levels of GRK5. Dysfunction of GRK5 impairs the desensitization of presynaptic muscarinic 2 (M2) autoreceptors, which results in presynaptic M2 hyperactivity and inhibits acetylcholine (ACh) release. GRK dysfunction also promotes a deleterious cycle that further increases β-amyloid accumulation and exaggerates tau hyperphosphorylation in the hippocampus. However, the pathogenic effect of GRK5 dysfunction through targeting tau hyperphosphorylation remains unclear. Here we examined not only the reduced membrane (functional) and elevated cytosolic levels of GRK5 but also the increased levels of hyperphosphorylated tau in the hippocampi of aged APP(swe) mice (11 months of age). Moreover, western blotting analyses revealed the changes in the location of activity of both protein kinase C (PKC) and glycogen synthase kinase3β (GSK3β) in the hippocampus of aged APP(swe) mice in which GRK5 translocation occurred. Moreover, treatment with methoctramine, a selective M2 antagonist, partially corrected the difference between wild-type control mice and GRK5-dysfunctional APP (swe) mice in hippocampal ACh release, PKC and GSK3β activities, as well as tau hyperphosphorylation. In contrast, the GSK3β inhibitor lithium chloride significantly reduced tau hyperphosphorylation in GRK5-defective APP (swe) mice, but failed to enhance PKC activity and ACh release in the hippocampi of GRK5-defective APP (swe) mice. Taken together, these findings indicate that GRK5 dysfunction accelerated tau hyperphosphorylation in APP(swe) mice by activating GSK3β through impaired cholinergic activity. Topics: Acetylcholine; Aging; Alzheimer Disease; Amyloid beta-Protein Precursor; Animals; Diamines; Disease Models, Animal; G-Protein-Coupled Receptor Kinase 5; Hippocampus; Humans; Lithium Chloride; Maze Learning; Mice; Mice, Inbred C57BL; Mice, Transgenic; Mutation; Neurons; Parasympatholytics; Phosphorylation; tau Proteins | 2014 |
Cooperative mechanisms involved in chronic antidiuretic response to bendroflumethiazide in rats with lithium-induced nephrogenic diabetes insipidus.
Previous studies of central diabetes insipidus suggested that thiazides acutely exerted a paradoxical antidiuresis by either indirectly activating volume-homeostatic reflexes to decrease distal fluid-delivery, or directly stimulating distal water-reabsorption. This study investigated whether the direct and indirect actions of bendroflumethiazide (BFTZ) simultaneously cooperated and also whether the renal nerves were involved in inducing long-term antidiuresis in nephrogenic diabetes insipidus (NDI). BFTZ or vehicle was gavaged into bilateral renal denervated and innervated rats with lithium-induced NDI for 10 days, constituting four groups. At one day before (D0) and one, five and ten days after starting administration of BFTZ or vehicle, rats were placed in metabolic cages to collect urine for 6 hours. BFTZ-treatment in both renal innervated and denervated rats caused equivalent reductions in urine-flow, creatinine clearance, lithium clearance and free-water clearance, but rises in urine-osmolality, fractional proximal reabsorption and fractional distal reabsorption at all days compared to D0, as well as to those of their relevant vehicle-received group. Therefore, the chronic antidiuretic response to BFTZ in conscious NDI rats was exerted through a concomitant cooperation of its direct distal effect of stimulating water-reabsorption and its indirect effect of reducing distal fluid-delivery by activating volume-homeostatic mechanisms, which appeared independent of the renal nerves. Topics: Animals; Antidiuretic Agents; Autonomic Denervation; Bendroflumethiazide; Biomarkers; Blood Pressure; Blood Urea Nitrogen; Body Weight; Creatinine; Diabetes Insipidus, Nephrogenic; Disease Models, Animal; Diuresis; Drinking; Kidney; Lithium Chloride; Male; Natriuresis; Osmolar Concentration; Rats; Rats, Sprague-Dawley; Time Factors; Urodynamics; Water-Electrolyte Balance | 2014 |
Cognitive impairment in temporal lobe epilepsy: role of online and offline processing of single cell information.
Cognitive impairment is a common comorbidity in temporal lobe epilepsy (TLE) and is often considered more detrimental to quality of life than seizures. While it has been previously shown that the encoding of memory during behavior is impaired in the pilocarpine model of TLE in rats, how this information is consolidated during the subsequent sleep period remains unknown. In this study, we first report marked deficits in spatial memory performance and severe cell loss in the CA1 layer of the hippocampus lower spatial coherence of firing in TLE rats. We then present the first evidence that the reactivation of behavior-driven patterns of activity of CA1 place cells in the hippocampus is intact in TLE rats. Using a template-matching method, we discovered that real-time (3-5 s) reactivation structure was intact in TLE rats. Furthermore, we estimated the entropy rate of short time scale (∼250 ms) bursting activity using block entropies and found that significant, extended temporal correlations exist in both TLE and control rats. Fitting a first-order Markov Chain model to these bursting time series, we found that long sequences derived from behavior were significantly enriched in the Markov model over corresponding models fit on randomized data confirming the presence of replay in shorter time scales. We propose that the persistent consolidation of poor spatial information in both real time and during bursting activity may contribute to memory impairments in TLE rats. Topics: Action Potentials; Animals; CA1 Region, Hippocampal; Cognition Disorders; Comorbidity; Disease Models, Animal; Epilepsy, Temporal Lobe; Lithium Chloride; Markov Chains; Maze Learning; Models, Neurological; Pilocarpine; Pyramidal Cells; Rats, Sprague-Dawley; Seizures; Sleep; Spatial Memory; Time Factors | 2014 |
The protective effect of melatonin against brain oxidative stress and hyperlocomotion in a rat model of mania induced by ouabain.
This study was designed to investigate the protective effect of melatonin in a preclinical animal model of mania induced by ouabain (OUA). Male Wistar rats were pretreated with melatonin (5 or 20mg/kg; intraperitoneal, i.p.) for seven days or with the mood stabilizer lithium chloride (positive control) (45 mg/kg, per oral, p.o.). One day after the last dose, animals received an intracerebroventricular (i.c.v.) injection of OUA (5μl, 10(-5)M), a Na(+)K(+)ATPase-inhibiting compound. Locomotor activity was assessed in the open-field test (OFT). The levels of reactive species (RS), protein carbonyl (PC) and non-protein thiols (NPSH), as well as the activities of the superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) were measured in the cerebral cortex and hippocampus of rats. OUA markedly increased the locomotor activity in the OFT, and the pretreatment with melatonin or lithium chloride prevented this effect. Melatonin treatment (similar to lithium) was also effective in preventing the following alterations elicited by OUA: increase of RS and PC levels; depletion of NPSH levels; increase of SOD activity; and inhibition of CAT and GPx activities. Moreover, we found that brain oxidative stress and behavioural alterations elicited by OUA were significantly correlated. Our study showed that Melatonin, similarly to lithium, protected against OUA-induced brain oxidative stress and hyperlocomotion in rats. Thus, our findings reinforce the notion that oxidative stress may play an important role in the manic-like behavioural. Therefore, we indicate that melatonin has antimanic-like action, suggesting a potential role for this substance in the pharmacological management of Bipolar disorder. Topics: Animals; Antimanic Agents; Bipolar Disorder; Catalase; Cerebral Cortex; Disease Models, Animal; Glutathione Peroxidase; Hippocampus; Lithium Chloride; Locomotion; Male; Melatonin; Motor Activity; Neuroprotective Agents; Ouabain; Oxidative Stress; Protein Carbonylation; Rats; Rats, Wistar; Superoxide Dismutase | 2014 |
Lithium enhances survival and regrowth of spinal motoneurons after ventral root avulsion.
During the clinical treatment of the brachial plexus root avulsion (BPRA), reimplantation surgery can not completely repair the motor function of the hand because the axonal growth velocity of the spinal motoneurons (MNs) is too slow to re-innervate the intrinsic hand muscles before muscle atrophy. Here, we investigated whether lithium can enhance the regenerative capacity of the spinal MNs in a rat model of BPRA.. The avulsion and immediate reimplantation of the C7 and C8 ventral roots were performed and followed with daily intraperitoneal administration of a therapeutic concentrationof LiCl. After a 20 week long-term rehabilitation, the motor function recovery of the injured forepaw was studied by a grasping test. The survival and regeneration of MNs were checked by choline acetyltransferase (ChAT) immunofluorescence and by Fluoro-Gold (FG) retrograde labeling through the median and ulnar nerves of the ventral horn MNs. The number and diameter of the nerve fibers in the median nerve were assessed by toluidine blue staining. Our results showed that lithium plus reimplantation therapy resulted in a significantly higher grasping strength of the digits of the injured forepaw. Lithium plus reimplantation allowed 45.1% ± 8.11% of ChAT-positive MNs to survive the injury and increased the number and diameter of nerve fibers in the median nerve. The number of FG-labeled regenerative MNs was significantly elevated in all of the reimplantation animals. Our present data proved that lithium can enhance the regenerative capacity of spinal MNs.. These results suggest that immediate administration of lithium could be used to assist reimplantation surgery in repairing BPRA injuries in clinical treatment. Topics: Animals; Axons; Brachial Plexus; Cell Survival; Cervical Vertebrae; Disease Models, Animal; Forelimb; Lithium Chloride; Male; Microsurgery; Motor Activity; Motor Neurons; Nerve Regeneration; Neuroprotective Agents; Neurosurgical Procedures; Radiculopathy; Random Allocation; Rats, Sprague-Dawley; Recovery of Function; Replantation; Spinal Cord | 2014 |
Lithium chloride therapy fails to improve motor function in a transgenic mouse model of Machado-Joseph disease.
The accumulation of misfolded proteins in neurons, leading to the formation of cytoplasmic and nuclear aggregates, is a common theme in age-related neurodegenerative diseases, possibly due to disturbances of the proteostasis and insufficient activity of cellular protein clearance pathways. Lithium is a well-known autophagy inducer that exerts neuroprotective effects in different conditions and has been proposed as a promising therapeutic agent for several neurodegenerative diseases. We tested the efficacy of chronic lithium (10.4 mg/kg) treatment in a transgenic mouse model of Machado-Joseph disease, an inherited neurodegenerative disease, caused by an expansion of a polyglutamine tract within the protein ataxin-3. A battery of behavioral tests was used to assess disease progression. In spite of activating autophagy, as suggested by the increased levels of Beclin-1, Atg7, and LC3-II, and a reduction in the p62 protein levels, lithium administration showed no overall beneficial effects in this model concerning motor performance, showing a positive impact only in the reduction of tremors at 24 weeks of age. Our results do not support lithium chronic treatment as a promising strategy for the treatment of Machado-Joseph disease (MJD). Topics: Animals; Apoptosis Regulatory Proteins; Ataxin-3; Autophagy; Autophagy-Related Protein 7; Beclin-1; Brain; Disease Models, Animal; Disease Progression; Exploratory Behavior; Humans; Lithium Chloride; Machado-Joseph Disease; Male; Mice, Transgenic; Microtubule-Associated Proteins; Motor Activity; Nerve Tissue Proteins; Neuromuscular Agents; Nuclear Proteins; Postural Balance; Repressor Proteins; Treatment Outcome; Tremor; Weight Loss | 2014 |
Running-based pica in rats. Evidence for the gastrointestinal discomfort hypothesis of running-based taste aversion.
Voluntary running in an activity wheel establishes aversion to paired taste in rats. A proposed mechanism underlying this taste aversion learning is gastrointestinal discomfort caused by running. We tested this hypothesis by measuring the pica behavior (kaolin clay intake) of rats, because it is known that rats engage in pica behavior after various nausea-inducing treatments including irradiation, motion sickness, and injection of emetic drugs such as lithium chloride (LiCl). Following a demonstration of the already-known phenomenon of LiCl-based pica in Experiment 1, we successfully showed running-based pica behavior in Experiment 2 where the running treatment was compared with a non-running control treatment (i.e., confinement in a locked wheel). These results suggest that not only LiCl but also running induces nausea in rats, supporting the gastrointestinal discomfort hypothesis of running-based taste aversion learning. Topics: Abdominal Pain; Aluminum Silicates; Animals; Avoidance Learning; Behavior, Animal; Clay; Disease Models, Animal; Dysgeusia; Emetics; Injections, Intraperitoneal; Kaolin; Lithium Chloride; Male; Models, Biological; Motor Activity; Nausea; Physical Exertion; Pica; Rats, Wistar; Stress, Physiological | 2014 |
The mood-stabilizer lithium prevents hippocampal apoptosis and improves spatial memory in experimental meningitis.
Pneumococcal meningitis is associated with high morbidity and mortality rates. Brain damage caused by this disease is characterized by apoptosis in the hippocampal dentate gyrus, a morphological correlate of learning deficits in experimental paradigms. The mood stabilizer lithium has previously been found to attenuate brain damage in ischemic and inflammatory diseases of the brain. An infant rat model of pneumococcal meningitis was used to investigate the neuroprotective and neuroregenerative potential of lithium. To assess an effect on the acute disease, LiCl was administered starting five days prior to intracisternal infection with live Streptococcus pneumoniae. Clinical parameters were recorded, cerebrospinal fluid (CSF) was sampled, and the animals were sacrificed 42 hours after infection to harvest the brain and serum. Cryosections of the brains were stained for Nissl substance to quantify brain injury. Hippocampal gene expression of Bcl-2, Bax, p53, and BDNF was analyzed. Lithium concentrations were measured in serum and CSF. The effect of chronic lithium treatment on spatial memory function and cell survival in the dentate gyrus was evaluated in a Morris water maze and by quantification of BrdU incorporation after LiCl treatment during 3 weeks following infection. In the hippocampus, LiCl significantly reduced apoptosis and gene expression of Bax and p53 while it increased expression of Bcl-2. IL-10, MCP-1, and TNF were significantly increased in animals treated with LiCl compared to NaCl. Chronic LiCl treatment improved spatial memory in infected animals. The mood stabilizer lithium may thus be a therapeutic alternative to attenuate neurofunctional deficits as a result of pneumococcal meningitis. Topics: Animals; Apoptosis; bcl-2-Associated X Protein; Brain; Chemokine CCL2; Dentate Gyrus; Disease Models, Animal; Down-Regulation; Interleukin-10; Lithium Chloride; Meningitis, Pneumococcal; Microscopy, Fluorescence; Neuroprotective Agents; Proto-Oncogene Proteins c-bcl-2; Rats; Spatial Memory; Streptococcus pneumoniae; Tumor Necrosis Factor-alpha; Tumor Suppressor Protein p53; Up-Regulation | 2014 |
The mood stabilizer lithium potentiates the antidepressant-like effects and ameliorates oxidative stress induced by acute ketamine in a mouse model of stress.
Evidence suggests that mammalian target of rapamycin activation mediates ketamine's rapid but transient antidepressant effects and that glycogen synthase kinase-3β inhibits this pathway. However, ketamine has associated psychotomimetic effects and a high risk of abuse. The mood stabilizer lithium is a glycogen synthase kinase-3 inhibitor with strong antisuicidal properties. Here, we used a mouse stress model to investigate whether adjunct lithium treatment would potentiate ketamine's antidepressant-like effects.. Mice received chronic restraint stress and long-term pre- or postketamine lithium treatment in drinking water. The effects of lithium on ketamine-induced antidepressant-like effects, activation of the mammalian target of rapamycin/brain-derived neurotrophic factor signaling pathways, oxidative stress, and dendritic spine density in the brain of mice were investigated.. Subtherapeutic (600 mg/L) lithium-pretreated mice exhibited an antidepressant-like response to an ineffective ketamine (2.5 mg/kg, intraperitoneally) challenge in the forced swim test. Both the antidepressant-like effects and restoration of dendritic spine density in the medial prefrontal cortex of stressed mice induced by a single ketamine (50 mg/kg) injection were sustained by postketamine treatment with 1200 mg/L of lithium for at least 2 weeks. These benefits of lithium treatments were associated with activation of the mammalian target of rapamycin/brain-derived neurotrophic factor signaling pathways in the prefrontal cortex. Acute ketamine (50 mg/kg) injection also significantly increased lipid peroxidation, catalase activity, and oxidized glutathione levels in stressed mice. Notably, these oxidative stress markers were completely abolished by pretreatment with 1200 mg/L of lithium.. Our results suggest a novel therapeutic strategy and justify the use of lithium in patients who benefit from ketamine. Topics: Affect; Animals; Antidepressive Agents; Antimanic Agents; Antioxidants; Behavior, Animal; Brain-Derived Neurotrophic Factor; Dendritic Spines; Depression; Disease Models, Animal; Dose-Response Relationship, Drug; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Hindlimb Suspension; Ketamine; Lithium Chloride; Male; Mice; Motor Activity; Oxidative Stress; Prefrontal Cortex; Protein Kinase Inhibitors; Signal Transduction; Stress, Psychological; Time Factors; TOR Serine-Threonine Kinases | 2014 |
Protein kinase C inhibition rescues manic-like behaviors and hippocampal cell proliferation deficits in the sleep deprivation model of mania.
Recent studies revealed that bipolar disorder may be associated with deficits of neuroplasticity. Additionally, accumulating evidence has implicated alterations of the intracellular signaling molecule protein kinase C (PKC) in mania.. Using sleep deprivation (SD) as an animal model of mania, this study aimed to examine the possible relationship between PKC and neuroplasticity in mania. Rats were subjected to SD for 72 h and tested behaviorally. In parallel, SD-induced changes in hippocampal cell proliferation were evaluated with bromodeoxyuridine (BrdU) labeling. We then examined the effects of the mood stabilizer lithium, the antipsychotic agent aripiprazole, and the PKC inhibitors chelerythrine and tamoxifen on both behavioral and cell proliferation impairments induced by SD. The antidepressant fluoxetine was used as a negative control.. We found that SD triggered the manic-like behaviors such as hyperlocomotion and increased sleep latency, and reduced hippocampal cell proliferation. These alterations were counteracted by an acute administration of lithium and aripiprazole but not of fluoxetine, and only a single administration of aripiprazole increased cell proliferation on its own. Importantly, SD rats exhibited increased levels of phosphorylated synaptosomal-associated protein 25 (SNAP-25) in the hippocampus and prefrontal cortex, suggesting PKC overactivity. Moreover, PKC inhibitors attenuated manic-like behaviors and rescued cell proliferation deficits induced by SD.. Our findings confirm the relevance of SD as a model of mania, and provide evidence that antimanic agents are also able to prevent SD-induced decrease of hippocampal cell proliferation. Furthermore, they emphasize the therapeutic potential of PKC inhibitors, as revealed by their antimanic-like and pro-proliferative properties. Topics: Animals; Antidepressive Agents, Second-Generation; Antimanic Agents; Antipsychotic Agents; Aripiprazole; Benzophenanthridines; Bipolar Disorder; Cell Proliferation; Disease Models, Animal; Fluoxetine; Hippocampus; Lithium Chloride; Male; Piperazines; Prefrontal Cortex; Protein Kinase C; Protein Kinase Inhibitors; Quinolones; Rats, Sprague-Dawley; Sleep Deprivation; Tamoxifen | 2014 |
Effect of low doses of cannabidiolic acid and ondansetron on LiCl-induced conditioned gaping (a model of nausea-induced behaviour) in rats.
To determine the minimally effective dose of cannabidiolic acid (CBDA) that effectively reduces lithium chloride (LiCl)-induced conditioned gaping reactions (nausea-induced behaviour) in rats and to determine if these low systemic doses of CBDA (5-0.1 μg·kg⁻¹) relative to those of CBD could potentiate the anti-nausea effects of the classic 5-hydroxytryptamine 3 (5-HT₃) receptor antagonist, ondansetron (OND).. We investigated the efficacy of low doses of CBDA to suppress acute nausea, assessed by the establishment of conditioned gaping to a LiCl-paired flavour in rats. The potential of threshold and subthreshold doses of CBDA to enhance the reduction of nausea-induced conditioned gaping by OND were then determined.. CBDA (at doses as low as 0.5 μg·kg⁻¹) suppressed nausea-induced conditioned gaping to a flavour. A low dose of OND (1.0 μg·kg⁻¹) alone reduced nausea-induced conditioned gaping, but when it was combined with a subthreshold dose of CBDA (0.1 μg·kg⁻¹) there was an enhancement in the suppression of LiCl-induced conditioned gaping.. CBDA potently reduced conditioned gaping in rats, even at low doses and enhanced the anti-nausea effect of a low dose of OND. These findings suggest that combining low doses of CBDA and OND will more effectively treat acute nausea in chemotherapy patients. Topics: Animals; Antiemetics; Antineoplastic Agents; Behavior, Animal; Cannabinoids; Conditioning, Psychological; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Synergism; Drug Therapy, Combination; Injections, Intraperitoneal; Lithium Chloride; Male; Nausea; Ondansetron; Random Allocation; Rats; Rats, Sprague-Dawley; Receptor, Serotonin, 5-HT1A; Serotonin 5-HT1 Receptor Antagonists; Serotonin 5-HT3 Receptor Antagonists; Taste | 2013 |
Prenatal immune challenge in rats increases susceptibility to seizure-induced brain injury in adulthood.
Maternal infection during pregnancy is associated with an increased risk of neurodevelopmental injury. Our aim was to investigate whether prenatal immune challenge could alter susceptibility to seizure-induced brain injury in adulthood. Pregnant Wistar rats were injected intraperitoneally with lipopolysaccharide (LPS) or normal saline (NS) at days 15 and 16 of gestation. At postnatal day 45, seizure susceptibility was assessed in response to lithium-pilocarpine (LiPC) in adult offspring. Four groups were studied, including normal control (NS-NS), prenatal inflammation (LPS-NS), adult seizure (NS-LiPC), and "two-hit" (LPS-LiPC) groups. Our results demonstrated that adult rat offspring of LPS-exposed dams showed significantly greater susceptibility to LiPC-induced seizures, as well as enhanced hippocampal neuronal injury after seizures. Furthermore, animals in the "two-hit" group performed significantly worse than those from the NS-LiPC group in the open field test and Morris water maze. Our findings suggest that prenatal immune activation can cause a long-lasting increase in seizure susceptibility and predispose the brain to the damaging effect of seizures later in life. Topics: Age Factors; Animals; Animals, Newborn; Brain Injuries; Disease Models, Animal; Disease Susceptibility; Exploratory Behavior; Female; Hippocampus; Learning Disabilities; Lipopolysaccharides; Lithium Chloride; Male; Maze Learning; Muscarinic Agonists; Pilocarpine; Pregnancy; Prenatal Exposure Delayed Effects; Rats; Rats, Wistar; Seizures; Time Factors | 2013 |
Lithium chloride alleviates neurodegeneration partly by inhibiting activity of GSK3β in a SCA3 Drosophila model.
Spinocerebellar ataxia type 3 (SCA3) is an autosomal dominant neurodegenerative disorder caused by the expansion of a CAG trinucelotide repeat that encodes an abnormal polyglutamine (PolyQ) tract in the disease protein, ataxin-3. The formation of neuronal intranuclear inclusions in the specific brain regions is one of the pathological hallmarks of SCA3. Acceleration of the degradation of the mutant protein aggregates is proven to produce beneficial effects in SCA3 and other PolyQ diseases. Lithium is known to be neuroprotective in various models of neurodegenerative disease and can reduce the mutant protein aggregates by inducing autophagy. In this study, we explored the therapeutic potential of lithium in a SCA3 Drosophila model. We showed that chronic treatment with lithium chloride at specific doses notably prevented eye depigmentation, alleviated locomotor disability, and extended the median life spans of SCA3 transgenic Drosophila. By means of genetic approaches, we showed that co-expressing the mutant S9E, which mimicked the phosphorylated S9 state of Shaggy as done by lithium, also partly decreased toxicity of gmr-SCA3tr-Q78. Taken together, our findings suggest that lithium is a promising therapeutic agent for the treatment of SCA3 and other PolyQ diseases. Topics: Age Factors; Animals; Animals, Genetically Modified; Ataxin-3; Disease Models, Animal; Dose-Response Relationship, Drug; Drosophila; Enzyme Activation; Eye; Gene Expression Regulation; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Humans; Lithium Chloride; Microscopy, Electron, Scanning; Motor Activity; Movement Disorders; Nerve Tissue Proteins; Neurodegenerative Diseases; Neuroprotective Agents; Nuclear Proteins; Peptides; Repressor Proteins | 2013 |
Speed modulation of hippocampal theta frequency correlates with spatial memory performance.
Hippocampal theta rhythm is believed to play a critical role in learning and memory. In animal models of temporal lobe epilepsy (TLE), there is evidence that alterations of hippocampal theta oscillations are involved in the cognitive impairments observed in this model. However, hippocampal theta frequency and amplitude at both the local field potential (LFP) and single unit level are strongly modulated by running speed, suggesting that the integration of locomotor information into memory processes may also be critical for hippocampal processing. Here, we investigate whether hippocampal speed-theta integration influences spatial memory and whether it could account for the memory deficits observed in TLE rats. LFPs were recorded in both Control (CTR) and TLE rats as they were trained in a spatial alternation task. TLE rats required more training sessions to perform the task at CTR levels. Both theta frequency and power were significantly lower in the TLE group. In addition, speed/theta frequency correlation coefficients and regression slopes varied from session to session and were worse in TLE. Importantly, there was a strong relationship between speed/theta frequency parameters and performance. Our analyses reveal that speed/theta frequency correlation with performance cannot merely be explained by the direct influence of speed on behavior. Therefore, variations in the coordination of theta frequency with speed may participate in learning and memory processes. Impairments of this function could explain at least partially memory deficits in epilepsy. Topics: Animals; Disease Models, Animal; Electrodes, Implanted; Electroencephalography; Epilepsy, Temporal Lobe; Food Deprivation; Hippocampus; Lithium Chloride; Maze Learning; Memory Disorders; Muscarinic Agonists; Pilocarpine; Rats; Rats, Sprague-Dawley; Space Perception; Theta Rhythm; Time Factors | 2013 |
Phospholamban knockout breaks arrhythmogenic Ca²⁺ waves and suppresses catecholaminergic polymorphic ventricular tachycardia in mice.
Phospholamban (PLN) is an inhibitor of cardiac sarco(endo)plasmic reticulum Ca²⁺ ATPase. PLN knockout (PLN-KO) enhances sarcoplasmic reticulum Ca²⁺ load and Ca²⁺ leak. Conversely, PLN-KO accelerates Ca²⁺ sequestration and aborts arrhythmogenic spontaneous Ca²⁺ waves (SCWs). An important question is whether these seemingly paradoxical effects of PLN-KO exacerbate or protect against Ca²⁺-triggered arrhythmias.. We investigate the impact of PLN-KO on SCWs, triggered activities, and stress-induced ventricular tachyarrhythmias (VTs) in a mouse model of cardiac ryanodine-receptor (RyR2)-linked catecholaminergic polymorphic VT.. We generated a PLN-deficient, RyR2-mutant mouse model (PLN-/-/RyR2-R4496C+/-) by crossbreeding PLN-KO mice with catecholaminergic polymorphic VT-associated RyR2-R4496C mutant mice. Ca²⁺ imaging and patch-clamp recording revealed cell-wide propagating SCWs and triggered activities in RyR2-R4496C+/- ventricular myocytes during sarcoplasmic reticulum Ca²⁺ overload. PLN-KO fragmented these cell-wide SCWs into mini-waves and Ca²⁺ sparks and suppressed the triggered activities evoked by sarcoplasmic reticulum Ca²⁺ overload. Importantly, these effects of PLN-KO were reverted by partially inhibiting sarco(endo)plasmic reticulum Ca²⁺ ATPase with 2,5-di-tert-butylhydroquinone. However, Bay K, caffeine, or Li⁺ failed to convert mini-waves to cell-wide SCWs in PLN-/-/RyR2-R4496C+/- ventricular myocytes. Furthermore, ECG analysis showed that PLN-KO mice are not susceptible to stress-induced VTs. On the contrary, PLN-KO protected RyR2-R4496C mutant mice from stress-induced VTs.. Our results demonstrate that despite severe sarcoplasmic reticulum Ca²⁺ leak, PLN-KO suppresses triggered activities and stress-induced VTs in a mouse model of catecholaminergic polymorphic VT. These data suggest that breaking up cell-wide propagating SCWs by enhancing Ca²⁺ sequestration represents an effective approach for suppressing Ca²⁺-triggered arrhythmias. Topics: 3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester; Animals; Caffeine; Calcium Signaling; Calcium-Binding Proteins; Calcium-Transporting ATPases; Cells, Cultured; Disease Models, Animal; Electrocardiography; Hydroquinones; Isoproterenol; Lithium Chloride; Mice; Mice, Knockout; Mutation, Missense; Myocytes, Cardiac; Patch-Clamp Techniques; Ryanodine Receptor Calcium Release Channel; Sarcoplasmic Reticulum; Tachycardia, Ventricular; Ultrasonography | 2013 |
Effects of transcranial focal electrical stimulation alone and associated with a sub-effective dose of diazepam on pilocarpine-induced status epilepticus and subsequent neuronal damage in rats.
Experiments were conducted to evaluate the effects of transcranial focal electrical stimulation (TFS) applied via tripolar concentric ring electrodes, alone and associated with a sub-effective dose of diazepam (DZP) on the expression of status epilepticus (SE) induced by lithium-pilocarpine (LP) and subsequent neuronal damage in the hippocampus. Immediately before pilocarpine injection, male Wistar rats received TFS (300Hz, 200-μs biphasic square charge-balanced 50-mA constant current pulses for 2min) alone or combined with a sub-effective dose of DZP (0.41mg/kg, i.p.). In contrast with DZP or TFS alone, DZP plus TFS reduced the incidence of, and enhanced the latency to, mild and severe generalized seizures and SE induced by LP. These effects were associated with a significant reduction in the number of degenerated neurons in the hippocampus. The present study supports the notion that TFS combined with sub-effective doses of DZP may represent a therapeutic tool to induce anticonvulsant effects and reduce the SE-induced neuronal damage. Topics: Analysis of Variance; Animals; Anticonvulsants; Cell Count; Deep Brain Stimulation; Diazepam; Disease Models, Animal; Fluoresceins; Hippocampus; Lithium Chloride; Male; Muscarinic Agonists; Neurons; Pilocarpine; Rats; Rats, Wistar; Reaction Time; Status Epilepticus | 2013 |
Tetrahydrocannabinolic acid reduces nausea-induced conditioned gaping in rats and vomiting in Suncus murinus.
We evaluated the anti-emetic and anti-nausea properties of the acid precursor of Δ(9) -tetrahydrocannabinol (THC), tetrahydrocannabinolic acid (THCA), and determined its mechanism of action in these animal models.. We investigated the effect of THCA on lithium chloride- (LiCl) induced conditioned gaping (nausea-induced behaviour) to a flavour, and context (a model of anticipatory nausea) in rats, and on LiCl-induced vomiting in Suncus murinus. Furthermore, we investigated THCA's ability to induce hypothermia and suppress locomotion [rodent tasks to assess cannabinoid1 (CB1 ) receptor agonist-like activity], and measured plasma and brain THCA and THC levels. We also determined whether THCA's effect could be blocked by pretreatment with SR141716 (SR, a CB1 receptor antagonist).. In rats, THCA (0.05 and/or 0.5 mg·kg(-1) ) suppressed LiCl-induced conditioned gaping to a flavour and context; the latter effect blocked by the CB1 receptor antagonist, SR, but not by the 5-hydroxytryptamine-1A receptor antagonist, WAY100635. In S. murinus, THCA (0.05 and 0.5 mg·kg(-1) ) reduced LiCl-induced vomiting, an effect that was reversed with SR. A comparatively low dose of THC (0.05 mg·kg(-1) ) did not suppress conditioned gaping to a LiCl-paired flavour or context. THCA did not induce hypothermia or reduce locomotion, indicating non-CB1 agonist-like effects. THCA, but not THC was detected in plasma samples.. THCA potently reduced conditioned gaping in rats and vomiting in S. murinus, effects that were blocked by SR. These data suggest that THCA may be a more potent alternative to THC in the treatment of nausea and vomiting. Topics: Animals; Antiemetics; Behavior, Animal; Body Temperature Regulation; Brain; Cannabinoid Receptor Antagonists; Disease Models, Animal; Dronabinol; Lithium Chloride; Male; Motor Activity; Nausea; Rats; Rats, Sprague-Dawley; Receptor, Cannabinoid, CB1; Shrews; Time Factors; Vomiting | 2013 |
Synergistic lithium chloride and glial cell line-derived neurotrophic factor delivery for peripheral nerve repair in a rodent sciatic nerve injury model.
Restoring peripheral nerve function after long gap peripheral nerve damage is challenging. Lithium chloride has demonstrated neuroprotective qualities and therefore shows great potential therapeutic benefit for some neurodegenerative diseases. This study examined the synergistic combination of glial cell line-derived neurotrophic factor and lithium chloride and its effect on peripheral nerve regeneration in a rat sciatic nerve injury model.. Polycaprolactone conduits with glial cell line-derived neurotrophic factor-loaded double-walled microspheres and local injections of lithium chloride, 1.5 or 2.5 mEq/kg body weight, were examined in a 15-mm rat sciatic nerve defect model. Eighteen Lewis male rats were divided randomly into control, 1.5-, and 2.5-mEq/kg lithium chloride injection groups. As an indicator of recovery, nerve sections were stained with S100, protein gene product 9.5 antibody, and toluidine blue.. Nerves stained with S100 and protein gene product 9.5 antibody demonstrated a significantly increased density of Schwann cells and axons in the 2.5-mEq/kg lithium chloride injection-treated groups compared with both the control and 1.5-mEq/kg lithium chloride injection-treated groups (p<0.05). At 6 weeks, histomorphometry revealed a significantly higher fiber density in the middle of the conduit for the 2.5-mEq/kg groups compared with the 1.5-mEq/kg group or the control group.. Polycaprolactone nerve guides with glial cell line-derived neurotrophic factor-loaded double-walled microspheres and local injections of lithium chloride, 2.5-mEq/kg, represent a potentially viable guiding material for Schwann cell and axon migration and proliferation for the treatment of peripheral nerve regeneration. Topics: Animals; Biopsy, Needle; Disease Models, Animal; Drug Synergism; Glial Cell Line-Derived Neurotrophic Factor; Immunohistochemistry; Lithium Chloride; Male; Nerve Regeneration; Neural Conduction; Peripheral Nerve Injuries; Random Allocation; Rats; Rats, Inbred Lew; Reference Values; Sciatic Nerve; Treatment Outcome | 2013 |
Evaluation of the potential of the phytocannabinoids, cannabidivarin (CBDV) and Δ(9) -tetrahydrocannabivarin (THCV), to produce CB1 receptor inverse agonism symptoms of nausea in rats.
The cannabinoid 1 (CB1 ) receptor inverse agonists/antagonists, rimonabant (SR141716, SR) and AM251, produce nausea and potentiate toxin-induced nausea by inverse agonism (rather than antagonism) of the CB1 receptor. Here, we evaluated two phytocannabinoids, cannabidivarin (CBDV) and Δ(9) -tetrahydrocannabivarin (THCV), for their ability to produce these behavioural effect characteristics of CB1 receptor inverse agonism in rats.. In experiment 1, we investigated the potential of THCV and CBDV to produce conditioned gaping (measure of nausea-induced behaviour) in the same manner as SR and AM251. In experiment 2, we investigated the potential of THCV and CBDV to enhance conditioned gaping produced by a toxin in the same manner as CB1 receptor inverse agonists.. SR (10 and 20 mg·kg(-1) ) and AM251 (10 mg·kg(-1) ) produced conditioned gaping; however, THCV (10 or 20 mg·kg(-1) ) and CBDV (10 or 200 mg·kg(-1) ) did not. At a subthreshold dose for producing nausea, SR (2.5 mg·kg(-1) ) enhanced lithium chloride (LiCl)-induced conditioned gaping, whereas Δ(9) -tetrahydrocannabinol (THC, 2.5 and 10 mg·kg(-1) ), THCV (2.5 or 10 mg·kg(-1) ) and CBDV (2.5 or 200 mg·kg(-1) ) did not; in fact, THC (2.5 and 10 mg·kg(-1) ), THCV (10 mg·kg(-1) ) and CBDV (200 mg·kg(-1) ) suppressed LiCl-induced conditioned gaping, suggesting anti-nausea potential.. The pattern of findings indicates that neither THCV nor CBDV produced a behavioural profile characteristic of CB1 receptor inverse agonists. As well, these compounds may have therapeutic potential in reducing nausea. Topics: Animals; Behavior, Animal; Cannabinoid Receptor Agonists; Cannabinoids; Disease Models, Animal; Dronabinol; Drug Partial Agonism; Lithium Chloride; Male; Nausea; Phytochemicals; Piperidines; Pyrazoles; Rats; Rats, Sprague-Dawley; Receptor, Cannabinoid, CB1; Rimonabant | 2013 |
Anandamide transport inhibition by ARN272 attenuates nausea-induced behaviour in rats, and vomiting in shrews (Suncus murinus).
To understand how anandamide transport inhibition impacts the regulation of nausea and vomiting and the receptor level mechanism of action involved. In light of recent characterization of an anandamide transporter, fatty acid amide hydrolase-1-like anandamide transporter, to provide behavioural support for anandamide cellular reuptake as a facilitated transport process.. The systemic administration of the anandamide transport inhibitor ARN272 ([(4-(5-(4-hydroxy-phenyl)-3,4-diaza-bicyclo[4.4.0]deca-1(6),2,4,7,9-pentaen-2-ylamino)-phenyl)-phenylamino-methanone]) was used to evaluate the prevention of LiCl-induced nausea-induced behaviour (conditioned gaping) in rats, and LiCl-induced emesis in shrews (Suncus murinus). The mechanism of how prolonging anandamide availability acts to regulate nausea in rats was explored by the antagonism of cannabinoid 1 (CB1) receptors with the systemic co-administration of SR141716.. The systemic administration of ARN272 produced a dose-dependent suppression of nausea-induced conditioned gaping in rats, and produced a dose-dependent reduction of vomiting in shrews. The systemic co-administration of SR141716 with ARN272 (at 3.0 mg·kg(-1)) in rats produced a complete reversal of ARN272-suppressed gaping at 1.0 mg·kg(-1). SR141716 alone did not differ from the vehicle solution.. These results suggest that anandamide transport inhibition by the compound ARN272 tonically activates CB1 receptors and as such produces a type of indirect agonism to regulate toxin-induced nausea and vomiting. The results also provide behavioural evidence in support of a facilitated transport mechanism used in the cellular reuptake of anandamide. Topics: Amidohydrolases; Animals; Antiemetics; Arachidonic Acids; Behavior, Animal; Biological Transport; Cannabinoid Receptor Antagonists; Disease Models, Animal; Dose-Response Relationship, Drug; Endocannabinoids; Isoenzymes; Lithium Chloride; Male; Nausea; Piperidines; Polyunsaturated Alkamides; Pyrazoles; Rats; Rats, Sprague-Dawley; Receptor, Cannabinoid, CB1; Rimonabant; Shrews; Vomiting | 2013 |
Dextran sodium sulfate inhibits the activities of both polymerase and reverse transcriptase: lithium chloride purification, a rapid and efficient technique to purify RNA.
Dextran sodium sulfate (DSS) is commonly used in mouse studies to induce a very reproducible colitis that effectively mimics the clinical and histological features of human inflammatory bowel disease (IBD) patients, especially ulcerative colitis. However, the mechanisms of action of DSS remain poorly understood, and observations by our laboratory and other groups indicate that DSS contamination of colonic tissues from DSS-treated mice potently inhibits the quantitative reverse-transcription polymerase chain reaction (qRT-PCR) amplification of mRNA.. A prior study used poly-A-mediated mRNA purification to remove DSS from RNA extracts, but we herein report a second efficient and cost-effective approach to counteract this inhibition, using lithium chloride precipitation to entirely remove DSS from RNAs. We also explored how DSS interferes with qRT-PCR process, and we report for the first time that DSS can alter the binding of reverse transcriptase to previously primed RNA and specifically inhibits the enzymatic activities of reverse transcriptase and Taq polymerase in vitro. This likely explains why DSS-treated colonic RNA is not suitable to qRT-PCR amplification without a previous purification step.. In summary, we provide a simple method to remove DSS from colonic RNAs, and we demonstrate for the first time that DSS can inhibit the activities of both polymerase and reverse transcriptase. In order to reliably analyze gene expression in the colonic mucosa of DSS-treated mice, the efficiency rate of qRT-PCR must be the same between all the different experimental groups, including the water-treated control group, suggesting that whatever the duration and the percentage of the DSS treatment, RNAs must be purified. Topics: Animals; Chemical Fractionation; Colitis; Dextran Sulfate; Disease Models, Animal; DNA-Directed DNA Polymerase; Humans; Lithium Chloride; Mice; Reverse Transcriptase Inhibitors; Reverse Transcriptase Polymerase Chain Reaction; RNA-Directed DNA Polymerase; RNA, Messenger | 2013 |
Lithium ameliorates open-field and elevated plus maze behaviors, and brain phospho-glycogen synthase kinase 3-beta expression in fragile X syndrome model mice.
To investigate whether lithium modifies open-field and elevated plus maze behavior, and brain phospho-glycogen synthase kinase 3 (P-GSK3beta) expression in Fmr1 knockout mice.. One hundred and eighty FVB mice, including knockout and wild type, with an age of 30 days were used. An open-field and elevated plus maze was utilized to test behavior, while western blot was used to measure the P-GSK3beta expression. Six groups were formed: control (saline), lithium chloride 30, 60, 90, 120, and 200 mg/kg. The experiments were carried out in the Institute of Neuroscience, Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China between January and June 2012.. Lithium significantly decreased total distance, crossing, central area time, and center entry in the open-field test (p<0.05), and significantly reduced open-arm tracking, open-arm entry, and open-arm time in the elevated plus maze (p<0.05) in knockout mice. In wild type mice, significant changes were observed in both behavior tests in some treatment groups. Lithium ameliorated P-GSK3beta expression in the hippocampus of all the treatment groups in knockout mice (p<0.05). However, lithium did not modify either GSK3beta expression in tissues of knockout mice, or P-GSK3beta or GSK3beta expression in tissues of wild type mice.. Lithium ameliorated open-field and elevated plus maze behaviors of Fmr1 knockout mice. This effect may be related to its enhancement of P-GSK3beta expression. Our findings suggest that lithium might have a therapeutic effect in fragile X syndrome. Topics: Animals; Antimanic Agents; Behavior, Animal; Blotting, Western; Brain; Disease Models, Animal; Fragile X Syndrome; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Immunohistochemistry; Lithium Chloride; Maze Learning; Mice; Mice, Knockout | 2013 |
Hippocampal group III mGlu receptor mRNA levels are not altered in specific mouse models of stress, depression and antidepressant action.
The neurotransmitter glutamate is increasingly being implicated as playing a role in the molecular pathology underlying depression. The group III family of metabotropic glutamate (mGlu) receptors (mGlu(4,) mGlu(7) and mGlu(8) receptors) remains the most poorly investigated of all glutamate receptors in this regard, despite early research efforts showing that they may be major players in stress-induced pathology, genetic vulnerability to the onset of depression and in the action of pharmacotherapies. To redress this deficit, we investigated whether the mRNA levels of the group III mGlu receptors display sensitivity to the preclinical stress models' chronic immobilisation stress (CIS) in BALB/c mice and chronic social defeat in BALB/c and C57BL/6j mice. We also investigated the potential of the mood stabiliser lithium to reverse any stress-induced alterations to expression levels of the group III mGlu receptors. Furthermore, we investigated if changes to hippocampal group III mGlu receptors are involved in the augmentation strategy of administering lithium in conjunction with the tricyclic antidepressant desipramine using BALB/c mice. Finally, we investigated whether differences in hippocampal group III mGlu receptors exist between the non-helpless NH/Rouen mouse line and the helpless H/Rouen line. We found no changes to hippocampal group III mGlu receptor expression in any of the stress models investigated, the H/Rouen mouse genetic model of depression or due to pharmacological treatment. This indicates that these receptors may not be involved in the manifestation of behavioural and physiological changes observed in these models and furthermore, may not contribute to the therapeutic mechanisms of the above mentioned pharmacotherapies. Topics: Animals; Antidepressive Agents; Depression; Desipramine; Disease Models, Animal; Gene Expression Regulation; Hippocampus; Lithium Chloride; Male; Mice; Mice, Inbred Strains; Receptors, Metabotropic Glutamate; Restraint, Physical; RNA, Messenger; Stress, Psychological; Transcription, Genetic | 2013 |
Activation of canonical wnt pathway promotes differentiation of mouse bone marrow-derived MSCs into type II alveolar epithelial cells, confers resistance to oxidative stress, and promotes their migration to injured lung tissue in vitro.
The differentiation of mesenchymal stem cells (MSCs) into type II alveolar epithelial (AT II) cells in vivo and in vitro, is critical for reepithelization and recovery in acute lung injury (ALI), but the mechanisms responsible for differentiation are unclear. In the present study, we investigated the role of the canonical wnt pathway in the differentiation of mouse bone marrow-derived MSCs (mMSCs) into AT II cells. Using a modified co-culture system with murine lung epithelial-12 (MLE-12) cells and small airway growth media (SAGM) to efficiently drive mMSCs differentiation, we found that GSK 3β and β-catenin in the canonical wnt pathway were up-regulated during differentiation. The levels of surfactant protein (SP) C, SPB, and SPD, the specific markers of AT II cells, correspondingly increased in mMSCs when Wnt3a or LiCl was added to the co-culture system to activate wnt/β-catenin signaling. The expression of these factors was depressed to some extent by inhibiting the pathway with the addition of DKK 1. The differentiation rate of mMSCs also depends on their abilities to accumulate and survive in inflammatory tissue. Our results suggested that the activation of wnt/β-catenin signaling promoted mMSCs migration towards ALI mouse-derived lung tissue in a Transwell assay, and ameliorated the cell death and the reduction of Bcl-2/Bax induced by H(2) O(2), which simultaneously caused reduced GSK 3β and β-catenin in mMSCs. These data supports a potential mechanism for the differentiation of mMSCs into AT II cells involving canonical wnt pathway activation, which may be significant to their application in ALI. Topics: Acute Lung Injury; Alveolar Epithelial Cells; Animals; beta Catenin; Biomarkers; Bone Marrow Cells; Cell Differentiation; Cell Movement; Cell Proliferation; Cells, Cultured; Coculture Techniques; Culture Media, Conditioned; Disease Models, Animal; Dose-Response Relationship, Drug; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Hydrogen Peroxide; Lithium Chloride; Male; Mesenchymal Stem Cell Transplantation; Mesenchymal Stem Cells; Mice; Mice, Inbred C57BL; Oxidants; Oxidative Stress; Re-Epithelialization; Time Factors; Tissue Culture Techniques; Wnt Signaling Pathway; Wnt3A Protein | 2013 |
Anti-anhedonic activity of long-term lithium treatment in rats exposed to repeated unavoidable stress.
Behavioural and neurochemical responses to palatable food exposure represent an index of hedonic competence. In rats, a palatable meal increases extra-neuronal dopamine levels in the nucleus accumbens shell (NAcS) that confers to it incentive salience and reinforcing value. Repeated stress exposure decreases dopamine output and impairs the NAcS dopaminergic response to palatable food and the competence to acquire a vanilla sugar (VS)-reinforced instrumental behaviour [VS-sustained appetitive behaviour (VAB)]. Moreover, chronic stress exposure disrupts reactivity to aversive stimuli. A 3-wk treatment with lithium, the gold-standard treatment in bipolar disorder, tonically reduces NAcS dopamine output and the reactivity to aversive stimuli. However, it does not affect the dopaminergic response to VS and the competence to acquire VAB. This study investigated whether repeated lithium administration is endowed with anti-anhedonic activity. The NAcS dopaminergic response to VS and the competence to acquire VAB and sucrose self-administration (SA), in terms of fixed-ratio (FR)1, FR5 and progressive ratio schedules of reinforcement, were studied in saline or lithium-treated groups of non-food-deprived rats exposed or not to repeated unavoidable stress. Chronic stress exposure impaired the NAcS dopaminergic response to VS, acquisition of VAB and sucrose SA, in terms of FR1 and FR5 schedules of reinforcement and breaking point score. Repeated lithium treatment restored these parameters to control group values, even when treatment began in rats already showing an anhedonia-like condition. Since the breaking point defines the reinforcement efficacy of a hedonic stimulus, the present data suggest that lithium treatment is endowed with anti-anhedonic activity in rats. Topics: Analysis of Variance; Animals; Antimanic Agents; Appetitive Behavior; Disease Models, Animal; Dopamine; Drug Administration Schedule; Lithium Chloride; Male; Microdialysis; Nucleus Accumbens; Rats; Rats, Sprague-Dawley; Reinforcement, Psychology; Stress, Psychological; Sweetening Agents | 2013 |
Lithium-induced effects on adult hippocampal neurogenesis are topographically segregated along the dorso-ventral axis of stressed mice.
Adult hippocampal neurogenesis is an important process in the regulation of cognition, stress responsivity, and sensitivity to antidepressant and mood stabiliser drugs. Increasing evidence suggests that the hippocampus is functionally divided along its axis with the ventral hippocampus (vHi) playing a preferential role in stress- and anxiety-related processes, while the dorsal hippocampus (dHi) is crucial for spatial learning and memory. However, it is currently unclear whether stress or the medications used to treat stress-related disorders, preferentially affect neurogenesis in the vHi rather than dHi. The aim of this study was to determine whether the mood stabiliser, lithium, preferentially affects cell proliferation and survival in the vHi rather than dHi under stress conditions. To this end, mice of the stress-sensitive strain, BALB/c, underwent chronic exposure to immobilisation stress plus lithium treatment (0.2% lithium-supplemented diet), and the rates of cell proliferation and survival were compared in the dHi and vHi. Lithium preferentially increased cell proliferation in the vHi under stress conditions only. This increase in cell proliferation was secondary to reductions in the survival of newly-born cells. Moreover, lithium-induced decreases in cell survival in the vHi were only observed under stress conditions. Taken together, the data suggest that the turnover of newly-born cells in response to chronic stress and lithium treatment occurs predominantly in the vHi rather than the dHi. This article is part of a Special Issue entitled 'Anxiety and Depression'. Topics: Analysis of Variance; Animals; Antimanic Agents; Body Weight; Bromodeoxyuridine; Cell Proliferation; Cell Survival; Disease Models, Animal; Hippocampus; Lithium Chloride; Male; Mice; Mice, Inbred BALB C; Neurogenesis; Neurons; Stress, Psychological | 2012 |
Pharmacological modulation of stress-induced behavioral changes in the light/dark exploration test in male C57BL/6J mice.
Psychological stress is a major risk factor for mood and anxiety disorders. However, the phenotypic manifestation of stress effects varies across individuals, likely due, in part, to genetic variation. Modeling the behavioral and neural consequences of stress across genetically diverse inbred mouse strains is a valuable approach to studying gene × stress interactions. Recent work has shown that C57BL/6J mice exposed to ten daily sessions of restraint stress exhibited increased exploration of the aversive light compartment in the light/dark exploration (LDE) test. Here we sought to clarify the nature of this stress-induced phenotype by testing the ability of treatment with various clinically efficacious drugs of different therapeutic classes to rescue it. Ten days of restraint increased light compartment exploration, reduced body weight and sensitized the corticosterone response to swim stress. Subchronic administration (during stress and LDE testing) of fluoxetine, and to a lesser extent, lithium chloride, rescued stress-induced LDE behavior. Chronic fluoxetine treatment prior to (plus during stress and testing) failed to block the LDE stress effect. Acute administration of antipsychotic haloperidol, anti-ADHD medication methylphenidate or anxiolytic drug chlordiazepoxide, prior to LDE testing, was also unable to normalize the LDE stress effect. Collectively, these data demonstrate a treatment-selective prophylactic rescue of a restraint stress-induced behavioral abnormality in the C57BL/6J inbred strain. Further work with this novel model could help elucidate genetic and neural mechanisms mediating stress-induced changes in mouse 'emotion-relevant' behaviors and, ultimately, further understanding of the pathophysiology of stress-related neuropsychiatric disorders. This article is part of a Special Issue entitled 'Anxiety and Depression'. Topics: Animals; Anti-Anxiety Agents; Antidepressive Agents; Body Weight; Central Nervous System Stimulants; Chlordiazepoxide; Corticosterone; Disease Models, Animal; Emotions; Exploratory Behavior; Fluoxetine; Light; Lithium Chloride; Male; Methylphenidate; Mice; Mice, Inbred C57BL; Restraint, Physical; Stress, Psychological; Swimming | 2012 |
The PPARγ agonist rosiglitazone prevents cognitive impairment by inhibiting astrocyte activation and oxidative stress following pilocarpine-induced status epilepticus.
Epilepsy is commonly associated with cognitive impairment. Astrocyte activation and oxidative stress occur following seizures, and play a role in the pathological injury of epilepsy with cognitive impairment. The peroxisome proliferator-activated receptor gamma (PPARγ) has been shown to exhibit neuroprotective and antioxidative effects in CNS diseases. Thus, we hypothesized that rosiglitazone, a PPARγ agonist, would prevent cognitive impairment by inhibiting astrocyte activation and regulating glutathione (GSH) homeostasis after status epilepticus (SE). Using a lithium pilocarpine-induced SE model, we found that rosiglitazone significantly prevented cognitive impairment induced by SE, and potently inhibited astrocyte activation with maintenance of GSH homeostasis in the hippocampus after SE. These protective effects were significantly reversed by co-treatment with the PPARγ antagonist T0070907. These data suggest that rosiglitazone can improve cognitive impairment, and inhibit astrocyte activation and oxidative damage following SE. Rosiglitazone may be a promising agent for treatment of epilepsy involving SE-induced cognitive impairment. Topics: Analysis of Variance; Animals; Astrocytes; Benzamides; Cell Count; Cognition Disorders; Disease Models, Animal; Glial Fibrillary Acidic Protein; Glutathione; Glutathione Disulfide; Hippocampus; Lithium Chloride; Male; Maze Learning; Oxidative Stress; Pilocarpine; PPAR gamma; Pyridines; Rats; Rats, Sprague-Dawley; Rosiglitazone; Status Epilepticus; Systole; Thiazolidinediones | 2012 |
Lithium attenuates peripheral neuropathy induced by paclitaxel in rats.
As a cancer chemotherapeutic agent, paclitaxel (Taxol® ) causes dose-related peripheral neuropathy in human beings. The mechanisms underlying this toxicity are currently unknown, and there are no validated treatments for its prevention or control. To assess whether lithium as a pre-treatment and at subtherapeutic dose could prevent the peripheral neuropathy produced by it, rats were treated with paclitaxel (2 mg/kg i.p. every other day for a total of 16 times) and/or lithium chloride (300 mg/l) via water supply. General toxicity and body-weight were measured regularly during the experiment. To evaluate the sensory and motor neuropathy hot-plate, open-field test and nerve conduction velocity were used. In rats treated with only paclitaxel, there was behavioural, electrophysiological and histological evidence of a mixed sensorimotor neuropathy after 16 injections. Lithium robustly reduced the rate of mortality and general toxicity. Paclitaxel-induced sensorimotor neuropathy was significantly improved as indicated by changes in hotplate latency, total distance moved and a significant increase in sciatic, sural and tail sensory or motor nerve conduction velocity. The same results were observed in histopathological examinations; however, dorsal root ganglion neurons did not significantly change in the paclitaxel-treated groups. These results suggest that lithium, at subtherapeutic doses, can prevent both motor and sensory components of paclitaxel neuropathy in rats. Thus, lithium at these doses, as an inexpensive and relatively safe salt, may be useful clinically in preventing the neuropathy induced by paclitaxel treatment. Topics: Animals; Antineoplastic Agents, Phytogenic; Disease Models, Animal; Lithium Chloride; Male; Motor Neurons; Neural Conduction; Neuroprotective Agents; Paclitaxel; Peripheral Nervous System Diseases; Rats; Rats, Sprague-Dawley | 2012 |
Lithium attenuates pain-related behavior in a rat model of neuropathic pain: possible involvement of opioid system.
Lithium is a major drug for bipolar disorder and mania. Recently, many studies have shown the neuroprotective effect of lithium in different models of neurodegenerative diseases. The present study was carried out to examine the effect of lithium in a rat model of neuropathic pain induced by partial sciatic nerve ligation and the possible role of opioid system in this effect. To do so, animals received acute injection of saline, lithium (5, 10 and 15 mg/kg,) and naloxone (1 mg/kg) or the combination of naloxone (1 mg/kg) with lithium (10 mg/kg) intraperitoneally on the testing days. Thermal hyperalgesia, mechanical and cold allodynia were measured on the days 3, 5, 7, 10 and 14 after surgery. Lithium decreased thermal hyperalgesia scores with dose of 5, 10 and 15 mg/kg and cold and mechanical allodynia scores with dose of 10 and 15 mg/kg, significantly. The opioid antagonist naloxone prevented the effect of lithium on thermal hyperalgesia and mechanical allodynia while it did not show any effect on the acetone-induced cold allodynia. Our results suggest that lithium can be considered as a therapeutic potential for the treatment of some aspects of neuropathic pain and that the opioid system may be involved in the lithium-induced attenuation of thermal hyperalgesia and mechanical allodynia. Topics: Animals; Behavior, Animal; Disease Models, Animal; Dose-Response Relationship, Drug; Hyperalgesia; Lithium Chloride; Male; Naloxone; Narcotic Antagonists; Nerve Tissue Proteins; Neuralgia; Neuroprotective Agents; Pain Measurement; Rats; Rats, Sprague-Dawley; Sciatic Nerve | 2012 |
Ondansetron interferes with unconditioned lying-on belly and acquisition of conditioned gaping induced by LiCl as models of nausea-induced behaviors in rats.
Rats selectively display conditioned gaping reactions when re-exposed to flavours previously paired with nausea-inducing treatments and drugs that reduce nausea also reduce these reactions, suggesting that they represent a model of nausea-induced behavior in rats. However, these reactions rely upon learning, they are not unconditional malaise-induced reactions. Here we compared the effectiveness of the anti-nausea drug, ondansetron (OND) to interfere with the establishment of conditioned gaping reactions and the unconditional malaise-induced reaction of lying on belly (LOB). Pretreatment with OND significantly reduced both LiCl-induced LOB and conditioned gaping reactions, without modifying conditioned taste avoidance. The frequency of gaping and duration of LOB were highly correlated. These results provide additional support for the validity of the conditioned gaping model as a rodent model of nausea-induced behavior. Topics: Analysis of Variance; Animals; Antiemetics; Avoidance Learning; Conditioning, Classical; Disease Models, Animal; Lithium Chloride; Male; Nausea; Ondansetron; Rats; Rats, Sprague-Dawley; Saccharin; Single-Blind Method; Taste; Time Factors; Video Recording | 2012 |
Direct and indirect contribution of human embryonic stem cell-derived hepatocyte-like cells to liver repair in mice.
Many studies of embryonic stem cells have investigated direct cell replacement of damaged tissues, but little is known about how donor cell-derived signals affect host tissue regeneration. We investigated the direct and indirect roles of human embryonic stem cell-derived cells in liver repair in mice.. To promote the initial differentiation of human embryonic stem cells into mesendoderm, we activated the β-catenin signaling pathway with lithium; cells were then further differentiated into hepatocyte-like cells. The differentiated cells were purified by indocyanine green staining and laser microdissection and characterized by immunostaining, polymerase chain reaction, biochemical function, electron microscopy, and transplantation analyses. To investigate indirect effects of these cells, secreted proteins (secretomes) were analyzed by a label-free quantitative mass spectrometry. Carbon tetrachloride was used to induce acute liver injury in mice; cells or secreted proteins were administered by intrasplenic or intraperitoneal injection, respectively.. The differentiated hepatocyte-like cells had multiple features of normal hepatocytes, engrafted efficiently into mice, and continued to have hepatic features; they promoted proliferation of host hepatocytes and revascularization of injured host liver tissues. Proteomic analysis identified proteins secreted from these cells that might promote host tissue repair. Injection of the secreted proteins into injured livers of mice promoted significant amounts of tissue regeneration without cell grafts.. Hepatocyte-like cells derived from human embryonic stem cells contribute to recovery of injured liver tissues in mice, not only by cell replacement but also by delivering trophic factors that support endogenous liver regeneration. Topics: Animals; Biomarkers; Carbon Tetrachloride; Cell Differentiation; Cell Proliferation; Cell Separation; Cells, Cultured; Chemical and Drug Induced Liver Injury; Coculture Techniques; Disease Models, Animal; Embryonic Stem Cells; Hepatocytes; Humans; Immunohistochemistry; Induced Pluripotent Stem Cells; Laser Capture Microdissection; Lithium Chloride; Liver; Liver Regeneration; Mass Spectrometry; Mice; Mice, Inbred BALB C; Mice, Nude; Microscopy, Electron; Neovascularization, Physiologic; Polymerase Chain Reaction; Proteomics; Time Factors; Wound Healing | 2012 |
Diverse effects of variant doses of dexamethasone in lithium-pilocarpine induced seizures in rats.
Corticosteroids are used in the management of several epileptic aliments; however, their effectiveness in combating seizures remains controversial, with pro- and anti-convulsive effects ascribed. The current study aimed to address the modulatory effect of dexamethasone (DEX) utilizing 3 dose levels (5, 10, and 20 mg/kg body mass of male Wistar rat) in the rat lithium-pilocarpine (Li-PIL) epilepsy model. Li-PIL induced seizures that were associated with neuronal cell loss in the CA3 region, and increased prostaglandin (PG)E(2), tumor necrosis factor (TNF)-α, interleukin (IL)-10, nitric oxide, and neutrophil infiltration in the hippocampus. However, Li-PIL compromised the oxidant-antioxidant balance of the hippocampus. Effective anticonvulsant activity was only observed with 10 mg DEX/kg body mass, which reduced seizure production and incidence, as well as neuronal cell loss in the CA3 region. At this anticonvulsant dose, enhancements in the antioxidant system and IL-10, as well as suppression of altered inflammatory markers were observed. Conversely, doubling the dose showed a tendency to shorten seizure latency, and neither affected seizure incidence nor CA3 neuronal cell loss. These effects were associated with an increase in levels of PGE(2) and TNF-α. The present study found a lack of protection at 5 mg DEX/kg body mass, an anticonvulsant effect at 10 mg/kg, and a loss of protection at 20 mg/kg in the Li-PIL epilepsy model, which indicates that there is an optimal dose of DEX for preventing the induction of seizures. Topics: Animals; Anticonvulsants; Antioxidants; CA3 Region, Hippocampal; Dexamethasone; Dinoprostone; Disease Models, Animal; Dose-Response Relationship, Drug; Inflammation; Interleukin-10; Lithium Chloride; Male; Nerve Degeneration; Neutrophil Activation; Nitric Oxide; Oxidative Stress; Pilocarpine; Rats; Rats, Wistar; Seizures; Tumor Necrosis Factor-alpha | 2012 |
Protective effects of acute lithium preconditioning against renal ischemia/reperfusion injury in rat: role of nitric oxide and cyclooxygenase systems.
Delayed graft function secondary to ischemia/reperfusion injury has been shown to be associated with increased rate of allograft failure following kidney transplantation. Previously, we have shown that chronic lithium pretreatment protects kidney against ischemia/reperfusion injury. In the present study we aimed to examine the effects of acute lithium administration on the renal ischemia/reperfusion injury in rat. Ischemia/reperfusion injury was induced by clamping left renal pedicle for 60 min, two weeks after right nephrectomy. The mechanism of lithium-mediated renoprotection was explored by combined use of lithium and nitro-l-arginine methyl ester (L-NAME) (non-selective nitric oxide synthase inhibitor) and/or indomethacin (non-selective cyclooxygenase pathway inhibitor). Lithium-treated animals were given 40 mg/kg lithium chloride intraperitoneally, 30 min before ischemia. To investigate the role of nitric oxide and cyclooxygenase pathways in renoprotective effect of lithium, L-NAME and/or indomethacin were administered before lithium injection. Serum creatinine, blood urea nitrogen, and renal histology were assessed after 24h of reperfusion. Lithium preconditioning significantly reduced creatinine and blood urea nitrogen (P<0.001) and improved renal histology. Administration of L-NAME completely reversed renoprotective effect of lithium. In contrast indomethacin significantly potentiated the lithium renoprotection. Moreover, co-administration of L-NAME and indomethacin completely abolished the protective effects of lithium. The results show that a single dose of lithium significantly improves renal function following ischemia/reperfusion injury. In conclusion, the ability of lithium to enhance renal tissue tolerance against ischemia/reperfusion injury suggests a potential clinical application in the setting of kidney transplantation. However, more detailed investigations are required before any definite conclusion. Topics: Animals; Antimanic Agents; Disease Models, Animal; Indomethacin; Ischemic Preconditioning; Kidney; Lithium Chloride; Male; NG-Nitroarginine Methyl Ester; Nitric Oxide; Prostaglandin-Endoperoxide Synthases; Protective Agents; Rats; Rats, Sprague-Dawley; Reperfusion Injury | 2012 |
Myocardial remodeling after large infarcts in rat converts post rest-potentiation in force decay.
Post-rest contraction (PRC) of cardiac muscle provides indirect information about the intracellular calcium handling.. Our aim was to study the behavior of PRC, and its underlying mechanisms, in rats with myocardial infarction.. Six weeks after coronary occlusion, the contractility of papillary muscles (PM) obtained from sham-operated (C, n=17), moderate infarcted (MMI, n=10) and large infarcted (LMI, n=14) rats was evaluated, following rest intervals of 10 to 60 seconds before and after incubation with lithium chloride (Li(+)) substituting sodium chloride or ryanodine (Ry). Protein expression of SR Ca(2+)-ATPase (SERCA2), Na(+)/Ca(2+) exchanger (NCX), phospholamban (PLB) and phospho-Ser(16)-PLB were analyzed by Western blotting.. MMI exhibited reduced PRC potentiation when compared to C. Opposing the normal potentiation for C, post-rest decays of force were observed in LMI muscles. In addition, Ry blocked PRC decay or potentiation observed in LMI and C; Li(+) inhibited NCX and converted PRC decay to potentiation in LMI. Although MMI and LMI presented decreased SERCA2 (72±7% and 47±9% of Control, respectively) and phospho-Ser(16)-PLB (75±5% and 46±11%, respectively) protein expression, overexpression of NCX (175±20%) was only observed in LMI muscles.. Our results showed, for the first time ever, that myocardial remodeling after MI in rats may change the regular potentiation to post-rest decay by affecting myocyte Ca(2+) handling proteins. Topics: Animals; Calcium; Calcium-Binding Proteins; Disease Models, Animal; Lithium Chloride; Myocardial Contraction; Myocardial Infarction; Myocytes, Cardiac; Papillary Muscles; Random Allocation; Rats; Rats, Wistar; Ryanodine; Sarcoplasmic Reticulum Calcium-Transporting ATPases; Sodium-Calcium Exchanger; Ventricular Remodeling | 2012 |
Changes in glucose metabolism and metabolites during the epileptogenic process in the lithium-pilocarpine model of epilepsy.
The metabolic and biochemical changes that occur during epileptogenesis remain to be determined. (18) F-Fluorodeoxyglucose positron emission tomography (FDG-PET) and proton magnetic resonance spectroscopy ((1) H MRS) are noninvasive techniques that provide indirect information on ongoing pathologic changes. We, therefore, utilized these methods to assess changes in glucose metabolism and metabolites in the rat lithium-pilocarpine model of epilepsy as markers of epileptogenesis from baseline to chronic spontaneous recurrent seizures (SRS).. PET and MRS were performed at baseline, and during the acute, subacute, silent, and chronic periods after lithium-pilocarpine induced status epilepticus (SE). Sequential changes in glucose metabolism on (18) F-FDG PET using SPM2 and the ratios of percent injected dose per gram (%ID)/g of regions of interest (ROIs) in the bilateral amygdala, hippocampus, basal ganglia with the thalamus, cortex, and hypothalamus normalized to the pons were determined. Voxels of interest (VOIs) on (1) H MRS were obtained at the right hippocampus and the basal ganglia. NAA/Cr levels and Cho/Cr at various time points were compared to baseline values.. Of 81 male Sprague-Dawley rats, 30 progressed to SRS. (18) F-FDG PET showed widespread global hypometabolism during the acute period, returning to baseline level during the subacute period. Glucose metabolism, however, declined in part of the hippocampus during the silent period, with the hypometabolic area progressively expanding to the entire limbic area during the chronic period. (1) H MRS showed that the NAA/Cr levels in the hippocampus and basal ganglia were reduced during the acute period and were not restored subsequently from the subacute to the chronic period without any significant change in the Cho/Cr ratio throughout the entire experiment.. Serial metabolic and biochemical changes in the lithium-pilocarpine model of epilepsy indirectly represent the process of human epileptogenesis. Following initial irreversible neural damage by SE, global glucose metabolism transiently recovered during the subacute period without neuronal recovery. Progressive glucose hypometabolism in the limbic area during the silent and chronic periods may reflect the important role of the hippocampus in the formation of ongoing epileptic network during epileptogenesis. Topics: Animals; Aspartic Acid; Brain Mapping; Choline; Creatine; Disease Models, Animal; Epilepsy; Fluorodeoxyglucose F18; Glucose; Hippocampus; Lithium Chloride; Magnetic Resonance Spectroscopy; Male; Pilocarpine; Positron-Emission Tomography; Rats; Rats, Sprague-Dawley; Time Factors; Tritium | 2012 |
MK-801 prevents overexpression of multidrug resistance protein 2 after status epilepticus.
The aim of this study was to investigate whether NMDA receptor was involved in the upregulation of multidrug resistance protein 2 (Mrp2) expression during status epilepticus (SE).. The alterations in the expression of Mrp2 at various time points after SE, and the inhibition of glutamate N-methyl-D-aspartate (NMDA) receptor on Mrp2 expression in hippocampus were both tested by quantitative real-time polymerase chain reaction and western blot. Moreover, immunofluorescence was also used to analyze the impact of the NMDA receptor antagonist, MK-801, on the distribution of Mrp2 in different brain areas.. The results showed that gene encoding Mrp2 was upregulated in hippocampus at 6 hours after the end of SE, and this initial increase was followed by gradual normalization. While between 3 and 72 hours after the end of SE, the protein level of Mrp2 was upregulated in hippocampus, with the highest level emerging at 24 hours. The increment of Mrp2 gene and protein induced by SE was prevented by MK-801 at 6 and 24 hours respectively after the end of SE in the hippocampus. Moreover, immunofluorescence showed that seizures-induced increase of Mrp2 expression was attenuated by the administration of MK-801 mainly in capillaries. Rats after SE exhibited a significant upregulation of Mrp2 in the capillary endothelial cells of the cerebral cortex, piriform cortex, and hippocampus, compared with those in control at 24 hours after the end of SE.. The results indicated that the NMDA receptor plays an important role in the upregulation of Mrp2 expression in the blood-brain barrier. Topics: Analysis of Variance; Animals; ATP Binding Cassette Transporter, Subfamily B; ATP-Binding Cassette Sub-Family B Member 4; Brain Waves; Disease Models, Animal; Dizocilpine Maleate; Electric Stimulation; Electroencephalography; Female; Gene Expression Regulation; Hippocampus; Lithium Chloride; Muscarinic Agonists; Neuroprotective Agents; Pilocarpine; Rats; Rats, Wistar; RNA, Messenger; Status Epilepticus; Time Factors; von Willebrand Factor | 2012 |
Interleukin-1β and microRNA-146a in an immature rat model and children with mesial temporal lobe epilepsy.
Increasing evidence indicates that neuroinflammation plays a critical role in the pathogenesis of mesial temporal lobe epilepsy (MTLE). The aim of this study was to investigate the dynamic expression of interleukin (IL)-1β as a proinflammatory cytokine and microRNA (miR)-146a as a posttranscriptional inflammation-associated microRNA (miRNA) in the hippocampi of an immature rat model and children with MTLE.. To study the expression of IL-1β and miR-146a, we performed a reverse transcription polymerase chain reaction, Western blot, and real-time quantitative PCR on the hippocampi of immature rats at 11 days of age. Expression was monitored in the acute, latent, and chronic stages of disease (2 h and 3 and 8 weeks after induction of lithium-pilocarpine status epilepticus, respectively), and in control hippocampal tissues corresponding to the same timeframes. Similar expression methods were applied to hippocampi obtained from children with MTLE and normal controls.. The expression of IL-1β and miR-146a in both children and immature rats with MTLE differs according to the stage of MTLE development. Both IL-1β and miR-146a are significantly up-regulated, but in opposite ways: IL-1β expression is highest in the acute stage, when expression of miR-146a is at its lowest level; miR-146a expression is highest in the latent stage, when IL-1β expression is at its lowest level. Both IL-1β and miR-146a are up-regulated in the chronic stage, but not as much as in the other stages.. Our study is the first to focus on the expression of miR-146a in the immature rat model of lithium-pilocarpine MTLE and in children with MTLE. We have detected that the expression of proinflammatory cytokine IL-1β and posttranscriptional inflammation-associated miR-146a is variable depending on the disease stage. Furthermore, both IL-1β and miR-146a are up-regulated in immature rats and children with MTLE. Our findings elucidate the role of inflammation in the pathogenesis of MTLE in the immature rat model and children. Therefore, modulation of the IL-1β-miR-146a axis may be a novel therapeutic target in the treatment of MTLE. Topics: Analysis of Variance; Animals; Animals, Newborn; Child; Disease Models, Animal; Epilepsy, Temporal Lobe; Female; Hippocampus; Humans; Interleukin-1beta; Lithium Chloride; Male; MicroRNAs; Pilocarpine; Random Allocation; Rats; Rats, Sprague-Dawley; RNA, Messenger; Up-Regulation | 2012 |
[Therapeutic effect of lithium chloride combined with cyclosporine A on mouse model with aplastic anemia].
Wnt signaling has been shown to inhibit adipogenic differentiation while inducing the osteogenic pathway of bone marrow stromal cells (BMSC). Patients with aplastic anemia (AA) often show excess fat accumulation in the bone marrow, possibly due to overactivation of the adipogenic pathway. Therefore, an activator of the Wnt signaling may alleviate the symptoms by enhancing the inhibition on the differentiation of BMSC towards adipocytes. To judge this hypothesis, the therapeutic effects of Wnt signaling activator lithium chloride (LiCl) combined with the currently used immunosuppressor cyclosporine A (CsA) on mice with AA in vivo was investigated. Mouse model with AA was established and the disease was confirmed by increased fat cell counts and decreased hematopoietic cell counts in the bone marrow of these animals. These mice treated with CsA 50 mg/(kg·d) alone or together with LiCl 20 mg/(kg·d), once daily for 5 d, then at day 14, 21 and 28 after establishment of mouse model with AA, the treatment effects were observed, including peripheral blood cells, bone marrow mononuclear cells (BMMNC) count and bone marrow biopsy examination in each group. The results showed that compared with the AA group, Hb content, WBC and BMMNC counts of CsA group and the combination group significantly increased. HE staining of bone marrow biopsy sample showed that the fat cells were significantly reduced in the bone marrow cavity (P < 0.05). Compared with the CsA group, Hb content, WBC and BMMNC counts of the combination group significantly increased (P < 0.05); HE staining of bone marrow biopsy sample showed that fat cells were reduced, the hematopoiesis of bone marrow was close to the normal. It is concluded that Wnt signal activator (LiCl) combined with CsA displayed a better treatment effect on AA in mouse models than the effect of using CsA only. They can promote the hematopoietic function of bone marrow, which may correlate with inhibiting differentiation of bone marrow mesenchymal stem cells into the fat cells by Wnt signaling. Topics: Anemia, Aplastic; Animals; Bone Marrow Examination; Cyclosporine; Disease Models, Animal; Drug Therapy, Combination; Female; Lithium Chloride; Mice; Mice, Inbred BALB C; Wnt Signaling Pathway | 2012 |
Effects of alpha-lipoic acid in an animal model of mania induced by D-amphetamine.
Oxidative stress and neurotrophic factors are involved in the pathophysiology of bipolar disorder (BD). Alpha-lipoic acid (ALA) is a naturally occurring compound with strong antioxidant properties. The present study investigated ALA effects in an amphetamine-induced model of mania.. In the reversal protocol, adult mice were first given d-amphetamine (AMPH) 2 mg/kg, intraperitoneally (i.p.) or saline for 14 days. Between days 8 and 14, the animals received ALA 50 or 100 mg/kg orally, lithium (Li) 47.5 mg/kg i.p., or saline. In the prevention paradigm, mice were pretreated with ALA, Li, or saline prior to AMPH. Locomotor activity was assessed in the open-field task. Superoxide dismutase (SOD) activity, reduced glutathione (GSH), and thiobarbituric acid-reactive substance (TBARS) levels were evaluated in the prefrontal cortex (PFC), hippocampus (HC), and striatum (ST). Brain-derived neurotrophic factor (BDNF) levels were measured in the HC.. ALA and Li prevented and reversed the AMPH-induced increase in locomotor activity. PREVENTION MODEL: ALA and Li co-administration with AMPH prevented the decrease in SOD activity induced by AMPH in the HC and ST, respectively; ALA and Li prevented GSH alteration in the HC and TBARS formation in all brain areas studied. REVERSAL MODEL: ALA reversed the decrease in SOD activity in the ST. TBARS formation was reversed by ALA and Li in all brain areas. Furthermore, ALA reversed AMPH-induced decreases in BDNF and GSH in the HC.. Our findings showed that ALA, similarly to Li, is effective in reversing and preventing AMPH-induced behavioral and neurochemical alterations, providing a rationale for the design of clinical trials investigating ALA's possible antimanic effect. Topics: Animals; Antimanic Agents; Bipolar Disorder; Brain; Brain-Derived Neurotrophic Factor; Central Nervous System Stimulants; Dextroamphetamine; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Administration Schedule; Glutathione; Lipid Peroxidation; Lithium Chloride; Male; Malondialdehyde; Mice; Motor Activity; Superoxide Dismutase; Thiobarbituric Acid Reactive Substances; Thioctic Acid | 2012 |
Lithium exacerbates hepatic ischemia/reperfusion injury by inhibiting GSK-3β/NF-κB-mediated protective signaling in mice.
Lithium (an inhibitor of GSK-3β activity) has beneficial effects on ischemia/reperfusion (I/R) injury in the central nervous system, heart and kidney. However, the role of lithium in hepatic I/R injury is unknown. The aim of this study was to assess the effects of lithium on hepatic I/R injury in a mouse model of partial hepatic I/R. Previous studies showed that lithium chloride (LiCl) can phosphorylate residue Ser9, inhibit GSK-3β activity, and improve I/R injury in other organs. In the present study, mice were pretreated with either vehicle or LiCl, which had similar effects on GSK-3β activity. Surprisingly, treatment with LiCl significantly exacerbated hepatic I/R injury, which was determined by serological and histological analyses. Acute and chronic LiCl treatment caused serious damage in hepatic I/R injury, including increased apoptosis and oxidative stress. To gain insight into the mechanism involved in this damage, the activity of nuclear factor-κB (NF-κB) (GSK-3β can regulate the transcriptional complex of NF-κB) was analyzed, which revealed that LiCl treatment significantly down-regulated the activity of NF-κB. The NF-κB-mediated protective genes were then further evaluated, including anti-apoptotic genes (RAF2, cIAP 2, Bfl-1 and cFLIP) and the antioxidant gene MnSOD. The expression of these protective genes was obviously suppressed compared with the vehicle group. Taken together, these findings show that lithium exacerbates hepatic I/R injury by suppressing the expression of GSK-3β/NF-κB-mediated protective genes. Topics: Animals; Apoptosis; CASP8 and FADD-Like Apoptosis Regulating Protein; Caspase 3; Disease Models, Animal; Gene Expression Regulation; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Inhibitor of Apoptosis Proteins; Lithium Chloride; Liver; Male; Mice; Mice, Inbred C57BL; Minor Histocompatibility Antigens; NF-kappa B; Oxidative Stress; Phosphorylation; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-bcl-2; Reactive Oxygen Species; Reperfusion Injury; RNA, Messenger; Serine; Signal Transduction; Superoxide Dismutase; Time Factors; TNF Receptor-Associated Factor 2 | 2012 |
Glycogen synthase kinase-3β inhibition improved survivability of mice infected with Burkholderia pseudomallei.
The disease melioidosis, caused by the soil bacteria Burkholderia pseudomallei, often manifests as acute septicemia with high fatality. Glycogen synthase kinase-3β (GSK3β) plays a key role during the inflammatory response induced by bacteria. We used a murine model of acute melioidosis to investigate the effects of LiCl, a GSK3 inhibitor on experimental animal survivability as well as TNF-α, IL-1β, IFN-γ, IL-10 and IL-1Ra cytokine levels in blood, lung, liver and spleen of B. pseudomallei-infected mice. Our results showed that administration of 100 μg/g LiCl improved survivability of mice infected with 5 X LD50 of B. pseudomallei. Bacterial counts in spleen, liver and lungs of infected mice administered with LiCl were lower than non-treated controls. Our data also revealed that GSK3β is phosphorylated in the spleen, liver and lung of animals infected with B. pseudomallei. However in infected animals administered with LiCl, higher levels of pGSK3 were detected in the organs. Levels of proinflammatory cytokines (TNF-α, IL-1β and IFN-γ) and anti-inflammatory cytokines (IL-10 and IL-1Ra) in sera and organs tested were elevated significantly following B. pseudomallei infection. With GSK3β inhibition, pro-inflammatory cytokines (TNF-α, IFN-γ, IL-1β) were significantly decreased in all the samples tested whilst the levels of anti-inflammatory cytokines, IL-10 (spleen and lung) and IL-1Ra (spleen, liver and sera) were further elevated. This study represents the first report implicating GSK3β in the modulation of cytokine production during B. pseudomallei infection thus reiterating the important role of GSK3β in the inflammatory response caused by bacterial pathogens. Topics: Animals; Bacteria; Bacterial Load; Blood Chemical Analysis; Burkholderia pseudomallei; Cytokines; Disease Models, Animal; Enzyme Inhibitors; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Immunologic Factors; Lithium Chloride; Liver; Lung; Male; Melioidosis; Mice; Mice, Inbred BALB C; Spleen; Survival Analysis; Treatment Outcome | 2012 |
[Effect of acute stress stimulation on the seizure induction in epileptic model rats].
This study was undertaken to observe the effect of acute stress on seizure occurrence in chronic period of epileptic model rats. Lithium-pilocarpine (LiCl-PILO)-induced epileptic rat model was constructed. At the spontaneous recurrent seizure period, acute stress stimulations such as cat's urine and foot electrical shock were applied to observe the behavioral changes and seizure occurrence. The results showed that after the cat's urine stimulation, the self-directed behaviors of the epileptic model rats decreased significantly, while the risk assessment behaviors increased significantly. The seizure occurrence, however, was not observed during the 45 min after the stimulation. Applying electrical foot shocks also did not evoke seizures in epileptic model rats. On the contrast, intra-peritoneal injection of low dose of pentylenetetrazole (PTZ, 30 mg/kg) evoked seizure more efficiently, and the duration of seizure activity was extensively prolonged in epileptic model rats than that of control rats. Taken together, these results indicate that although applying stress stimulations such as cat's urine and electrical foot shock cause several behavioral changes, they are not severe enough to evoke seizure in epileptic model rats. Topics: Animals; Behavior, Animal; Disease Models, Animal; Epilepsy; Lithium Chloride; Pentylenetetrazole; Pilocarpine; Rats; Seizures; Stress, Physiological | 2012 |
Lithium and valproate modulate antioxidant enzymes and prevent ouabain-induced oxidative damage in an animal model of mania.
In this study, we assessed the oxidative stress parameters in rats submitted to an animal model of mania induced by ouabain (OUA), which included the use of lithium (Li) and valproate (VPA). Li and VPA treatment reversed and prevented the OUA-induced damage in these structures, however, this effect varies depending on the brain region and treatment regimen. Moreover, the activity of the antioxidant enzymes, namely, superoxide dismutase (SOD) and catalase (CAT) was found to be increased and decreased, respectively, in the brain of OUA-administered rats. Li and VPA modulated SOD and CAT activities in OUA-subjected rats in both experimental models. Our results support the notion that Li and VPA exert antioxidant-like properties in the brain of rats submitted to animal model of mania induced by ouabain. Topics: Analysis of Variance; Animals; Antimanic Agents; Bipolar Disorder; Brain; Catalase; Disease Models, Animal; Drug Interactions; Gene Expression Regulation, Enzymologic; Injections, Intraventricular; Lithium Chloride; Male; Ouabain; Protein Carbonylation; Rats; Rats, Wistar; Superoxide Dismutase; Thiobarbituric Acid Reactive Substances; Valproic Acid | 2011 |
Transcranial direct current stimulation decreases convulsions and spatial memory deficits following pilocarpine-induced status epilepticus in immature rats.
Transcranial direct current stimulation (tDCS) is a recently available, noninvasive brain stimulation technique. The effects of cathodal tDCS on convulsions and spatial memory after status epilepticus (SE) in immature animals were investigated.. Rats underwent lithium-pilocarpine-induced SE at postnatal day (P) 20-21 and received daily 30-min cathodal tDCS for 2 weeks at P23-36 through a unilateral epicranial electrode at 200μA. After tDCS, convulsions over 2 weeks were estimated by 20-h/day video monitoring. The rats were tested in a water maze for spatial learning at P50-53 and the brains were examined for cell loss and mossy fiber sprouting.. Long-term treatment with weak cathodal tDCS reduced SE-induced hippocampal cell loss, supragranular and CA3 mossy fiber sprouting, and convulsions (reduction of 21%) in immature rats. The tDCS treatment also rescued cognitive impairment following SE.. These findings suggested that cathodal tDCS has neuroprotective effects on the immature rat hippocampus after pilocarpine-induced SE, including reduced sprouting and subsequent improvements in cognitive performance. Such treatment might also have an antiepileptic effect. Topics: Animals; Disease Models, Animal; Electric Stimulation Therapy; Hippocampus; Lithium Chloride; Male; Maze Learning; Memory Disorders; Mossy Fibers, Hippocampal; Nerve Degeneration; Pilocarpine; Rats; Rats, Wistar; Seizures; Status Epilepticus | 2011 |
Experience with activity based anorexia enhances conditioned taste aversion learning in rats.
Activity based anorexia (ABA) is a model that mimics the self-starvation and hyperactivity features of anorexia nervosa (AN). This study investigated whether a history of ABA will enhance food avoidance learning and retard its extinction in female rats. We compared the acquisition and extinction of a conditioned taste aversion (CTA) in naive (ad lib with no access to RW), ABA, and pair-fed to the food intake of ABA (with access to a locked RW) female Sprague-Dawley rats. The CTA conditioning was conducted after the ABA and pair-fed rats had recovered to their pre-food restriction body weights. For the CTA learning, 0.3M sucrose consumption was followed by low doses LiCl (0.009M or 0.018M at 1.33ml/100g of body weight, IP) injection. The results revealed that the ABA rats acquired an aversion to sucrose significantly sooner than the naive controls. Furthermore, they completely avoided sucrose while the naive and pair-fed controls still sampled it by the end of 10 conditioning trials. When extinction was assessed by 1-bottle and 2-bottle tests, the ABA rats extinguished more slowly than the controls. However, the differences in sucrose aversion extinction between the ABA and control rats were only significant in the 1-bottle test. These data suggest that experience with AN-like behaviors results in an acquired aversion to a preferred food sooner and a longer retention of the negative food associations. These findings have implications for understanding the persistence of aberrant eating behaviors in eating disorders. Topics: Animals; Anorexia Nervosa; Avoidance Learning; Conditioning, Classical; Disease Models, Animal; Extinction, Psychological; Female; Food; Lithium Chloride; Motor Activity; Rats; Rats, Sprague-Dawley; Sucrose | 2011 |
Selective loss and axonal sprouting of GABAergic interneurons in the sclerotic hippocampus induced by LiCl-pilocarpine.
In this study, we performed immunohistochemistry for somatostatin (SS), neuropeptide Y (NPY), and parvalbumin (PV) in LiCl-pilocarpine-treated rats to observe quantitative changes and axonal sprouting of GABAergic interneurons in the hippocampus, especially in the sclerotic hippocampus. Fluoro-Jade B (FJB) was performed to detect the specific degeneration of GABAergic interneurons. Compared with age-matched control rats, there were fewer SS/NPY/PV-immunoreactive (IR) interneurons in the hilus of the sclerotic hippocampus in pilocarpine-treated rats; hilar dentritic inhibitory interneurons were most vulnerable. FJB stain revealed degeneration was evident at 2 months after status epilepticus. Some SS-IR and NPY-IR interneurons were also stained for FJB, but there was no evidence of degeneration of PV-IR interneurons. Axonal sprouting of GABAergic interneurons was present in the hippocampus of epileptic rats, and a dramatic increase of SS-IR fibers was observed throughout all layers of CA1 region in the sclerotic hippocampus. These results confirm selective loss and degeneration of a specific subset of GABAergic interneurons in specific subfields of the hippocampus. Axonal sprouting of inhibitory GABAergic interneurons, especially numerous increase of SS-IR neutrophils within CA1 region of the sclerotic hippocampus, may constitute the aberrant inhibitory circum and play a significant role in the generation and compensation of temporal lobe epilepsy. Topics: Animals; Axons; Disease Models, Animal; gamma-Aminobutyric Acid; Hippocampus; Interneurons; Lithium Chloride; Male; Nerve Degeneration; Neuropeptide Y; Parvalbumins; Pilocarpine; Rats; Rats, Sprague-Dawley; Sclerosis; Somatostatin; Status Epilepticus | 2011 |
Normal prion protein in Drosophila enhances the toxicity of pathogenic polyglutamine proteins and alters susceptibility to oxidative and autophagy signaling modulators.
To investigate the in vivo functions of normal prion protein (PrP) in Drosophila, we utilized characterized transgenic flies expressing ³(F)⁴-tagged mouse PrP (Mo-PrP³(F)⁴). The neurotoxicity of pathogenic Machado-Joseph Disease (MJD) glutamine (Q) 78 and 127Q proteins were enhanced by the co-expression of Mo-PrP³(F)⁴in the fly eyes, while the eyes of controls flies and flies expressing Mo-PrP³(F)⁴) alone or together with MJD-Q27 or 20Q proteins did not show any defect. Susceptibilities to H₂O₂, paraquat, and Dithiothreitol (DTT) were altered in Mo-PrP³(F)⁴ flies. In addition, Mo-PrP³(F)⁴ flies were significantly more susceptible to the perturbation of autophagy signaling by an autophagy inhibitor, 3-methyladenine (3-MA), and inducer, LiCl. Taken together, our data suggest that Mo-PrP³(F)⁴ may enhance the neurotoxicity of pathogenic Poly-Q proteins by perturbing oxidative and autophagy signaling. Topics: Adenine; Animals; Animals, Genetically Modified; Autophagy; Disease Models, Animal; Dithiothreitol; Drosophila melanogaster; Eye; Lithium Chloride; Machado-Joseph Disease; Mice; Models, Genetic; Neurons; Oxidative Stress; Paraquat; Peptides; Prions; Unfolded Protein Response; Water | 2011 |
Memantine reduces mania-like symptoms in animal models.
Memantine, a selective antagonist of the N-methyl-D-aspartate receptor, is approved for the treatment of moderate to severe Alzheimer's disease. Ion dysregulation is thought to be involved in the pathophysiology of bipolar illness, suggesting that memantine may be effective in treating bipolar manic and/or depressive episodes. We utilized two preclinical models of mania that mimic pathophysiologic changes seen in bipolar illness to examine the potential efficacy of memantine in the treatment of this disorder. Locomotor hyperactivity of male Sprague-Dawley rats in an open field was induced with intracerebroventricular (ICV) administration of 10(-3) M ouabain. Memantine (2.5, 5 or 7.5mg/kg), lithium (6.75 mEq/kg), or vehicle were administered acutely via intraperitoneal injection immediately prior to ouabain, then chronically for 7 days (oral memantine 20, 30, and 40 mg/kg/day in water; lithium 2.4 g/kg food). In a second model of bipolar disorder, cycling between population spikes and epileptiform bursts was investigated in rat hippocampal slices treated with ouabain (3.3 μM) alone or in combination with memantine (0.5, 1.0, and 5.0 μM). Ouabain-induced hyperlocomotion was normalized with acute and chronic lithium and chronic use of memantine. Memantine delayed the onset of ouabain-induced-cycling in hippocampal slices. Memantine may have antimanic properties. Topics: Action Potentials; Animals; Antimanic Agents; Bipolar Disorder; Disease Models, Animal; Dose-Response Relationship, Drug; Enzyme Inhibitors; Excitatory Amino Acid Antagonists; Exploratory Behavior; Hippocampus; In Vitro Techniques; Lithium Chloride; Male; Memantine; Ouabain; Rats; Rats, Sprague-Dawley; Statistics, Nonparametric; Time Factors | 2011 |
Long-term treatment with lithium alleviates memory deficits and reduces amyloid-β production in an aged Alzheimer's disease transgenic mouse model.
The glycogen synthase kinase-3β (GSK3β) pathway plays a central role in Alzheimer's disease (AD) and its deregulation accounts for many of the pathological hallmarks of AD. Lithium, which modulates GSK3β activity, has been shown to reduce amyloid production and tau phosphorylation in pre-pathological AD mouse models. In this study, we investigated the effects of chronic LiCl treatment in aged double transgenic mice (AβPPSwe/PS1A246E). We found that chronic lithium treatment decreased the γ-cleavage of amyloid-β protein precursor, further reduced amyloid-β production and senile plaque formation, accompanied by the improvement in spatial learning and memory abilities. Because autophagy may play an important role in the pathology of AD, we also assessed the autophagy activity and found that the chronic lithium treatment attenuated the autophagy activation in this AD mouse model. Our results suggest that prolonged lithium treatment, even during the later stages of AD, could be an effective therapeutics. Topics: Aging; Alzheimer Disease; Amyloid beta-Peptides; Animals; Disease Models, Animal; Down-Regulation; Female; Glycogen Synthase Kinase 3; Lithium Chloride; Memory Disorders; Mice; Mice, Transgenic; Time Factors; Treatment Outcome | 2011 |
AKT kinase activity is required for lithium to modulate mood-related behaviors in mice.
Bipolar disorder (BP) is a debilitating psychiatric disorder, affecting ∼2% of the worldwide population, for which the etiological basis, pathogenesis, and neurocircuitry remain poorly understood. Individuals with BP suffer from recurrent episodes of mania and depression, which are commonly treated with the mood stabilizer lithium. However, nearly half of BP patients do not respond adequately to lithium therapy and the clinically relevant mechanisms of lithium for mood stabilization remain elusive. Here, we modeled lithium responsiveness using cellular assays of glycogen synthase kinase 3 (GSK-3) signaling and mood-related behavioral assays in inbred strains of mice that differ in their response to lithium. We found that activating AKT through phosphosrylation of a key regulatory site (Thr308) was associated with lithium response-activation of signaling pathways downstream of GSK-3 in cells and attenuation of mood-related behaviors in mice-and this response was attenuated by selective and direct inhibition of AKT kinase activity. Conversely, the expression of constitutively active AKT1 in both the cellular and behavioral assays conferred lithium sensitivity. In contrast, selective and direct GSK-3 inhibition by the ATP-competitive inhibitor CHIR99021 bypassed the requirement for AKT activation and modulated behavior in both lithium-responsive and non-responsive mouse strains. These results distinguish the mechanism of action of lithium from direct GSK-3 inhibition both in vivo and in vitro, and highlight the therapeutic potential for selective GSK-3 inhibitors in BP treatment. Topics: Amphetamine; Analysis of Variance; Animals; Antimanic Agents; Cell Line, Transformed; Corpus Striatum; Disease Models, Animal; Drug Administration Routes; Drug Administration Schedule; Drug Interactions; Enzyme Inhibitors; Gene Expression Regulation, Enzymologic; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Hippocampus; Humans; Lithium Chloride; Male; Mice; Mice, Inbred C57BL; Mice, Inbred DBA; Mood Disorders; Proto-Oncogene Proteins c-akt; Signal Transduction; Transfection | 2011 |
Behavioral and pharmacological assessment of a potential new mouse model for mania.
Bipolar disorder (BPD) is a devastating long-term disease for which a significant symptom is mania. Rodent models for mania include psychostimulant-induced hyperactivity and single gene alterations, such as in the Clock or DAT genes, but there is still a pressing need for additional models. Recently, our lab isolated a line of mice, termed Madison (MSN), that exhibit behavioral characteristics that may be analogous to symptoms of mania. In this study we quantified possible traits for mania and tested the response to common anti-BPD drugs in altering the behavioral profiles observed in this strain. Relative to other mouse lines, MSN mice showed significant elevations of in-cage hyperactivity levels, significant decreases in daytime sleep, and significant increases in time swimming in the forced swim test. In terms of sexual behavior, the MSN mice showed significantly higher number of mounts and a trend toward higher time mounting. In separate studies, olanzapine and lithium (or respective controls) were administered to MSN mice for at least 2weeks and response to treatments was evaluated. Olanzapine (1mg/kg/day) significantly decreased in-cage hyperactivity and significantly increased time sleeping. Lithium (0.2-0.4% in food) significantly decreased in-cage hyperactivity. Given the behavioral phenotypes and the response to anti-BPD treatments, we propose that MSN mice may provide a possible new model for understanding the neural and genetic basis of phenotypes related to mania and for developing pharmaceutical treatments. Topics: Animals; Antimanic Agents; Behavior, Animal; Benzodiazepines; Bipolar Disorder; Body Weight; Dark Adaptation; Disease Models, Animal; Exploratory Behavior; Lithium Chloride; Mice; Olanzapine; Sexual Behavior, Animal; Sleep; Swimming | 2011 |
Specific role of VTA dopamine neuronal firing rates and morphology in the reversal of anxiety-related, but not depression-related behavior in the ClockΔ19 mouse model of mania.
Lithium has been used extensively for mood stabilization, and it is particularly efficacious in the treatment of bipolar mania. Like other drugs used in the treatment of psychiatric diseases, it has little effect on the mood of healthy individuals. Our previous studies found that mice with a mutation in the Clock gene (ClockΔ19) have a complete behavioral profile that is very similar to human mania, which can be reversed with chronic lithium treatment. However, the cellular and physiological effects that underlie its targeted therapeutic efficacy remain unknown. Here we find that ClockΔ19 mice have an increase in dopaminergic activity in the ventral tegmental area (VTA), and that lithium treatment selectively reduces the firing rate in the mutant mice with no effect on activity in wild-type mice. Furthermore, lithium treatment reduces nucleus accumbens (NAc) dopamine levels selectively in the mutant mice. The increased dopaminergic activity in the Clock mutants is associated with cell volume changes in dopamine neurons, which are also rescued by lithium treatment. To determine the role of dopaminergic activity and morphological changes in dopamine neurons in manic-like behavior, we manipulated the excitability of these neurons by overexpressing an inwardly rectifying potassium channel subunit (Kir2.1) selectively in the VTA of ClockΔ19 mice and wild-type mice using viral-mediated gene transfer. Introduction of this channel mimics the effects of lithium treatment on the firing rate of dopamine neurons in ClockΔ19 mice and leads to a similar change in dopamine cell volume. Furthermore, reduction of dopaminergic firing rates in ClockΔ19 animals results in a normalization of locomotor- and anxiety-related behavior that is very similar to lithium treatment; however, it is not sufficient to reverse depression-related behavior. These results suggest that abnormalities in dopamine cell firing and associated morphology underlie alterations in anxiety-related behavior in bipolar mania, and that the therapeutic effects of lithium come from a reversal of these abnormal phenotypes. Topics: Action Potentials; Analysis of Variance; Animals; Anxiety; Bipolar Disorder; Cell Count; Chromatography, High Pressure Liquid; CLOCK Proteins; Dark Adaptation; Depression; Disease Models, Animal; Dopamine; Green Fluorescent Proteins; Helplessness, Learned; Histones; In Vitro Techniques; Lithium Chloride; Locomotion; Male; Maze Learning; Mice; Mice, Inbred BALB C; Mice, Knockout; Mutation; Neurons; Patch-Clamp Techniques; Swimming; Tyrosine 3-Monooxygenase; Ventral Tegmental Area | 2011 |
Acute corticosterone increases conditioned spontaneous orofacial behaviors but fails to influence dose related LiCl-induced conditioned "gaping" responses in a rodent model of anticipatory nausea.
Acute administration of corticosterone has been shown to facilitate learning in a number of associative paradigms, including LiCl-induced conditioned taste aversion learning. The present study examined the effects of acute corticosterone on LiCl-induced conditioned anticipatory nausea in male rats. Anticipatory nausea is produced by pairing a novel distinctive context with the nausea-inducing effects of a toxin, such as LiCl. Following a number of pairings of the context with the effects of the toxin, rats will display a distinctive conditioned "gaping" response when placed into the context in a drug free state. Adult male Long-Evans rats were injected (intraperitoneal, ip) with a LiCl solution (32, 64, or 128 mg/kg, 0.15M) or saline (NaCl, 0.15 M) followed 10 min later by either corticosterone (5 mg/kg) or β-cyclodextrin vehicle (45%) prior to placement in a distinctive context on four conditioning days (72 h apart) for 30 min. On the conditioning test day rats were placed in the distinctive context in a drug-free state and orofacial and somatic responses were video-recorded for 10 min. Gaping responses increased with increasing doses of LiCl in a linear fashion (P<0.01) but were not significantly influenced by the corticosterone treatment. In contrast, significant increases in the frequency of conditioned spontaneous orofacial behaviors on the drug free test day were produced by the corticosterone treatment during the acquisition phase, whereas LiCl treatment during acquisition had no significant effect on these behaviors. Thus, acute corticosterone did not alter the strength of conditioning of anticipatory nausea in rats. Topics: Animals; Anticipation, Psychological; Behavior, Animal; Conditioning, Psychological; Corticosterone; Disease Models, Animal; Dose-Response Relationship, Drug; Face; Lithium Chloride; Male; Mouth; Movement; Nausea; Rats; Rats, Long-Evans | 2011 |
Inhibition of glycogen synthase kinase-3 is necessary for the rapid antidepressant effect of ketamine in mice.
Topics: Amino Acid Substitution; Animals; Antidepressive Agents; Cerebral Cortex; Depression; Disease Models, Animal; Drug Evaluation, Preclinical; Electroshock; Gene Knock-In Techniques; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Helplessness, Learned; Hippocampus; Ketamine; Lithium Chloride; Mice; Nerve Tissue Proteins; Phosphorylation; Phosphoserine; Point Mutation; Protein Processing, Post-Translational | 2011 |
Simultaneous conditioning of "gaping" responses and taste avoidance in rats injected with LiCl and saccharin: examining the role of context and taste cues in the rodent model of anticipatory nausea.
This study examined whether rats can simultaneously learn to associate lithium chloride (LiCl)-induced nausea with both contextual and intravascular taste cues. During the conditioning phase (4 days, 72h apart), 32 male Long Evans rats were injected intraperitoneally with either isotonic saline (NaCl), lithium chloride (LiCl, 127mg/kg), saline plus 2% saccharin (NaCl+Saccharin), or lithium chloride plus 2% saccharin (LiCl+Saccharin) immediately prior to a 30min exposure to a novel context. 72h following the final conditioning day, each animal was re-exposed to the context on a drug-free test day. The next day, animals received a 24h 2-bottle preference test with a choice between water and a palatable saccharin solution. Results showed that animals treated with LiCl during conditioning, with or without saccharin, displayed significantly higher levels of conditioned gaping responses, indicative of nausea, upon re-exposure to the context, relative to NaCl and NaCl+Saccharin controls. Animals administered LiCl+Saccharin during conditioning also displayed significant conditioned taste avoidance to the saccharin solution during the two bottle choice test. These results indicate that systemic administration (intraperitoneal) of a LiCl+Saccharin solution is effective in simultaneously conditioning toxin elicited nausea to both internal (taste) and external (context) cues. Topics: Animals; Anticipation, Psychological; Antimanic Agents; Avoidance Learning; Behavior, Animal; Conditioning, Classical; Cues; Disease Models, Animal; Lithium Chloride; Male; Nausea; Rats; Rats, Long-Evans; Saccharin; Sweetening Agents; Taste Perception | 2011 |
Diazoxide reduces status epilepticus neuron damage in diabetes.
Diabetic hyperglycemia is associated with seizure severity and may aggravate brain damage after status epilepticus. Our earlier studies suggest the involvement of ATP-sensitive potassium channels (K(ATP)) in glucose-related neuroexcitability. We aimed to determine whether K(ATP) agonist protects against status epilepticus-induced brain damage. Adult male Sprague-Dawley rats were divided into two groups: the streptozotocin (STZ)-induced diabetes (STZ) group and the normal saline (NS) group. Both groups were treated with either diazoxide (15 mg/kg, i.v.) (STZ + DZX, NS + DZX) or vehicle (STZ + V, NS + V) before lithium-pilocarpine-induced status epilepticus. We evaluated seizure susceptibility, severity, and mortality. The rats underwent Morris water-maze tests and hippocampal histopathology analyses 24 h post-status epilepticus. A multi-electrode recording system was used to study field excitatory postsynaptic synaptic potentials (fEPSP). RNA interference (RNAi) to knockdown Kir 6.2 in a hippocampal cell line was used to evaluate the effect of diazoxide in the presence of high concentration of ATP. Seizures were less severe (P < 0.01), post-status epilepticus learning and memory were better (P < 0.05), and neuron loss in the hippocampal CA3 area was lower (P < 0.05) in the STZ + DZX than the STZ + V group. In contrast, seizure severity, post-status epilepticus learning and memory, and hippocampal CA3 neuron loss were comparable in the NS + DZX and NS + V groups. fEPSP was lower in the STZ + DZX but not in the NS + DZX group. The RNAi study confirmed that diazoxide, with its K(ATP)-opening effects, could counteract the K(ATP)-closing effect by high dose ATP. We conclude that, by opening K(ATP), diazoxide protects against status epilepticus-induced neuron damage during diabetic hyperglycemia. Topics: Adenosine Triphosphate; Analysis of Variance; Animals; Blood Glucose; Cell Line, Transformed; Diabetes Mellitus, Experimental; Diazoxide; Disease Models, Animal; Dose-Response Relationship, Drug; Excitatory Postsynaptic Potentials; Gene Expression Regulation; Hippocampus; In Situ Nick-End Labeling; In Vitro Techniques; Lithium Chloride; Male; Maze Learning; Neurons; Patch-Clamp Techniques; Potassium Channels, Inwardly Rectifying; Rats; Rats, Sprague-Dawley; RNA, Small Interfering; Status Epilepticus; Transfection; Vasodilator Agents | 2010 |
Lithium ameliorates altered glycogen synthase kinase-3 and behavior in a mouse model of fragile X syndrome.
Fragile X syndrome (FXS), the most common form of inherited mental retardation and a genetic cause of autism, results from mutated fragile X mental retardation-1 (Fmr1). This study examined the effects on glycogen synthase kinase-3 (GSK3) of treatment with a metabotropic glutamate receptor (mGluR) antagonist, MPEP, and the GSK3 inhibitor, lithium, in C57Bl/6 Fmr1 knockout mice. Increased mGluR signaling may contribute to the pathology of FXS, and the mGluR5 antagonist MPEP increased inhibitory serine-phosphorylation of brain GSK3 selectively in Fmr1 knockout mice but not in wild-type mice. Inhibitory serine-phosphorylation of GSK3 was lower in Fmr1 knockout, than wild-type, mouse brain regions and was increased by acute or chronic lithium treatment, which also increased hippocampal brain-derived neurotrophic factor levels. Fmr1 knockout mice displayed alterations in open-field activity, elevated plus-maze, and passive avoidance, and these differences were ameliorated by chronic lithium treatment. These findings support the hypothesis that impaired inhibition of GSK3 contributes to the pathogenesis of FXS and support GSK3 as a potential therapeutic target. Topics: Animals; Avoidance Learning; Disease Models, Animal; Fragile X Mental Retardation Protein; Fragile X Syndrome; Glycogen Synthase Kinase 3; Lithium Chloride; Male; Mice; Mice, Inbred C57BL; Mice, Knockout | 2010 |
Antimanic efficacy of retigabine in a proposed mouse model of bipolar disorder.
Retigabine is a novel compound with anticonvulsant efficacy. Preclinical studies have indicated that the compound, like other anticonvulsants may also have antimanic efficacy. Bipolar disorder is characterized by episodes of depression and mania, which show a progressively faster recurrence and an increase in severity with time. Recurrence of episodes in bipolar disorders is suggested to reflect a process of sensitization. Repeated intermittent administration of amphetamine in rodents gives rise to a behavioral sensitization phenomena argued to have similarities to the sensitization found in humans. The aims were therefore to explore the predictive validity of the amphetamine sensitization model as a behavioral model of mania by testing the effect of a range of antimanic drugs and to evaluate the effect of retigabine on the sensitized amphetamine response. Furthermore, since withdrawal from prolonged use of amphetamine in humans can result in depression symptoms it was explored if a state of anhedonia could be assessed by testing saccharine preference before and during the withdrawal period of the model. The tested antimanic drugs (lithium, valproate, carbamazepine and lamotrigine) all attenuated the sensitized locomotor activity induced and with the exception of valproate the found effects seemed not to be due to sedation. Interestingly, retigabine also attenuated the induced locomotor activity with a lowest effective dose at 1.0mg/kg, whereas basal locomotor activity was only reduced at 8.0mg/kg, suggesting a genuine calming and antimanic-like efficacy of the compound. In addition, saccharine preference data suggest that withdrawal from the d-amphetamine pre-treatment regimen may induce depression-like behavior indicating that both manic and depression-like behavior is expressed in this mouse model. Topics: Amphetamine; Analysis of Variance; Animals; Anticonvulsants; Antimanic Agents; Behavior, Animal; Bipolar Disorder; Carbamates; Disease Models, Animal; Dose-Response Relationship, Drug; Food Preferences; Lithium Chloride; Male; Mice; Motor Activity; Phenylenediamines; Saccharin; Treatment Outcome | 2010 |
Antiepileptic drugs combined with high-frequency electrical stimulation in the ventral hippocampus modify pilocarpine-induced status epilepticus in rats.
To evaluate the effects of high-frequency electrical stimulation (HFS) in both ventral hippocampi, alone and combined with a subeffective dose of antiepileptic drugs, during the status epilepticus (SE) induced by lithium-pilocarpine (LP).. Male Wistar rats, stereotactically implanted in both ventral hippocampi, were injected with pilocarpine (30 mg/kg, i.p.) 24 h after lithium (3 mEq/kg) administration. One minute following pilocarpine injection, HFS (pulses of 60 mus width at 130 Hz at subthreshold intensities and applied during 3 h) was applied alone or combined with subeffective doses of antiepileptic drugs.. HFS alone reduced the incidence of severe generalized seizures. This effect was not evident when HFS was combined with phenytoin (33.3 mg/kg, i.p.). HFS combined with diazepam (0.41 mg/kg, i.p.) or phenobarbital (10 mg/kg, i.p.) reduced the incidence of severe generalized seizures and mortality rate, and augmented the latency to first forelimb clonus, generalized seizure, and status epilepticus (SE). When combined with gabapentin (46 mg/kg, i.p.), HFS reduced the incidence of severe generalized seizures, enhanced latency to SE, and decreased mortality rate.. Subeffective doses of antiepileptic drugs that increase the gamma-aminobutyric acid (GABA)ergic neurotransmission may represent a therapeutic tool to augment the HFS-induced anticonvulsant effects. Topics: Amines; Animals; Anticonvulsants; Cyclohexanecarboxylic Acids; Disease Models, Animal; Electric Stimulation; Electrodes, Implanted; Gabapentin; gamma-Aminobutyric Acid; Hippocampus; Lithium Chloride; Male; Phenytoin; Pilocarpine; Rats; Rats, Wistar; Seizures; Status Epilepticus; Synaptic Transmission | 2010 |
A novel animal model to evaluate the ability of a drug delivery system to promote the passage through the BBB.
The purpose of this investigation was to explore the potentiality of a novel animal model to be used for the in vivo evaluation of the ability of a drug delivery system to promote the passage through the blood-brain barrier (BBB) and/or to improve the brain localization of a bioactive compound. A Tween 80-coated poly-L-lactid acid nanoparticles was used as a model of colloidal drug delivery system, able to trespass the BBB. Tacrine, administered in LiCl pre-treated rats, induces electrocorticographic seizures and delayed hippocampal damage. The toxic effects of tacrine-loaded poly-L-lactid acid nanoparticles (5mg/kg), a saline solution of tacrine (5mg/kg) and an empty colloidal nanoparticle suspension were compared following i.p. administration in LiCl-pre-treated Wistar rats. All the animals treated with tacrine-loaded nanoparticles showed an earlier outcome of CNS adverse symptoms, i.e. epileptic onset, with respect to those animals treated with the free compound (10 min vs. 22 min respectively). In addition, tacrine-loaded nanoparticles administration induced damage of neuronal cells in CA1 field of the hippocampus in all treated animals, while the saline solution of tacrine only in 60% of animals. Empty nanoparticles provided similar results to control (saline-treated) group of animals. In conclusion, the evaluation of time-to-onset of symptoms and the severity of neurodegenerative processes induced by the tacrine-lithium model of epilepsy in the rat, could be used to evaluate preliminarily the capability of a drug delivery system to trespass (or not) the BBB in vivo. Topics: Animals; Biological Transport; Blood-Brain Barrier; CA1 Region, Hippocampal; Capillary Permeability; Central Nervous System Agents; Cholinesterase Inhibitors; Disease Models, Animal; Drug Delivery Systems; Epilepsy; Lithium Chloride; Nanoparticles; Polyesters; Rats; Tacrine | 2010 |
Effects of mood stabilizers on hippocampus and amygdala BDNF levels in an animal model of mania induced by ouabain.
There is a body of evidence suggesting that BDNF is involved in bipolar disorder (BD) pathogenesis. Intracerebroventricular (ICV) injection of ouabain (OUA), a specific Na(+)/K(+) ATPase inhibitor, induces hyperlocomotion in rats, and has been used as an animal model of mania. The present study aims to investigate the effects of the lithium (Li) and valproate (VPT) in an animal model of mania induced by ouabain. In the reversal model, animals received a single ICV injection of OUA or cerebrospinal fluid (aCSF). From the day following the ICV injection, the rats were treated for 6 days with intraperitoneal (IP) injections of saline (SAL), Li or VPT twice a day. In the maintenance treatment (prevention model), the rats received IP injections of Li, VPT, or SAL twice a day for 12 days. In the 7th day of treatment the animals received a single ICV injection of either OUA or aCSF. After the ICV injection, the treatment with the mood stabilizers continued for more 6 days. Locomotor activity was measured using the open-field test and BDNF levels were measured in rat hippocampus and amygdala by sandwich-ELISA. Li and VPT reversed OUA-related hyperactive behavior in the open-field test in both experiments. OUA decreased BDNF levels in first and second experiments in hippocampus and amygdala and Li treatment, but not VPT reversed and prevented the impairment in BDNF expression after OUA administration in these cerebral areas. Our results suggest that the present model fulfills adequate face, construct and predictive validity as an animal model of mania. Topics: Amygdala; Analysis of Variance; Animals; Antimanic Agents; Bipolar Disorder; Brain-Derived Neurotrophic Factor; Disease Models, Animal; Drug Interactions; Enzyme-Linked Immunosorbent Assay; Gene Expression Regulation; Hippocampus; Lithium Chloride; Male; Motor Activity; Ouabain; Rats; Rats, Wistar; Valproic Acid | 2010 |
Early experience alters limbic forebrain Fos responses to a stressful interoceptive stimulus in young adult rats.
The present study examined whether manipulation of the early life experience of rat pups might alter the later ability of an interoceptive challenge to recruit central neural circuits that receive visceral sensory signals and generate stress responses. For this purpose, litters were exposed to daily maternal separation for either 15min (MS-15) or 180min (MS-180) from postnatal days (P)1 to P10. Pups in control litters were raised under standard conditions (i.e., no separations). Similar to previous reports in adult rats, adolescent rats (P35-45) with a developmental history of MS-15 displayed less anxiety-like behavior on the elevated plus maze compared to control and MS-180 rats. As young adults (P50-60), rats were anesthetized and perfused with fixative 90min after viscerosensory stimulation via lithium chloride (LiCl, 0.15M, 1% BW, i.p.) or saline control. In all three rearing groups, Fos activation within brainstem and forebrain regions of interest was significantly enhanced after LiCl vs. saline. MS-15 rats tended to display fewer LiCl-activated neurons in most brain regions compared with rats in the other two rearing groups. This trend reached significance within the dorsal bed nucleus of the stria terminalis. The ability of MS-15 to alter limbic forebrain activation in rats after an interoceptive challenge may contribute to the effect of early life experience to modulate physiological and behavioral stress responses more generally. Topics: Adjuvants, Immunologic; Age Factors; Analysis of Variance; Animals; Animals, Newborn; Behavior, Animal; Disease Models, Animal; Dopamine beta-Hydroxylase; Female; Gene Expression Regulation, Developmental; Limbic System; Lithium Chloride; Male; Maternal Deprivation; Maze Learning; Neurons; Pregnancy; Prosencephalon; Random Allocation; Rats; Rats, Sprague-Dawley; Stress, Psychological; Time Factors | 2010 |
Characterization and in vivo pharmacological rescue of a Wnt2-Gata6 pathway required for cardiac inflow tract development.
Little is understood about the molecular mechanisms underlying the morphogenesis of the posterior pole of the heart. Here we show that Wnt2 is expressed specifically in the developing inflow tract mesoderm, which generates portions of the atria and atrio-ventricular canal. Loss of Wnt2 results in defective development of the posterior pole of the heart, resulting in a phenotype resembling the human congenital heart syndrome complete common atrio-ventricular canal. The number and proliferation of posterior second heart field progenitors is reduced in Wnt2(-/-) mutants. Moreover, these defects can be rescued in a temporally restricted manner through pharmacological inhibition of Gsk-3beta. We also show that Wnt2 works in a feedforward transcriptional loop with Gata6 to regulate posterior cardiac development. These data reveal a molecular pathway regulating the posterior cardiac mesoderm and demonstrate that cardiovascular defects caused by loss of Wnt signaling can be rescued pharmacologically in vivo. Topics: Animals; Disease Models, Animal; Enzyme Inhibitors; Female; Fetal Heart; GATA6 Transcription Factor; Gene Expression Regulation, Developmental; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Heart Defects, Congenital; Humans; Lithium Chloride; Mice; Mice, Inbred C57BL; Mice, Knockout; Mice, Mutant Strains; Models, Cardiovascular; Phenotype; Pregnancy; Signal Transduction; Wnt2 Protein | 2010 |
Involvement of nitric oxide-cGMP pathway in the anticonvulsant effects of lithium chloride on PTZ-induced seizure in mice.
Lithium is still the mainstay in the treatment of affective disorders as a mood stabilizer. Lithium also shows some anticonvulsant properties. While the underlying mechanisms of action of lithium are not yet exactly understood, we used a model of clonic seizure induced by pentylenetetrazole (PTZ) in male NMRI mice to investigate whether the anticonvulsant effect of lithium is mediated via NO-cGMP pathway. Injection of a single effective dose of lithium chloride (25 mg/kg) intraperitoneally (i.p.) increased significantly the seizure threshold (P<0.01). The anticonvulsant properties of the effective dose of lithium were prevented by pre-treatment with the per se non-effective doses of L-ARG [the substrate for nitric oxide synthase; NOS] (30 and 50 mg/kg) or sildenafil [a phosphodiesterase 5 inhibitor] (10 and 20 mg/kg). L-NAME [a non-specific NOS inhibitor] (5, 15 and 30 mg/kg), 7-NI [a specific neural NOS inhibitor] (30 and 60 mg/kg) or MB [a guanylyl cyclase inhibitor] (0.5 and 1 mg/kg) augmented the anticonvulsant effect of a sub-effective dose of lithium (10 mg/kg, i.p.). Whereas several doses of aminoguanidine [an inducible NOS inhibitor] (20, 50 and 100 mg/kg) failed to alter the anticonvulsant effect of lithium. Our findings demonstrated that nitric oxide-cyclic GMP pathway could be involved in the anticonvulsant properties of the lithium chloride. In addition, the role of constitutive NOS versus inducible NOS is prominent in this phenomenon. Topics: Animals; Anticonvulsants; Arginine; Convulsants; Cyclic GMP; Disease Models, Animal; Dose-Response Relationship, Drug; Enzyme Inhibitors; Indazoles; Injections, Intraperitoneal; Lithium Chloride; Male; Methylene Blue; Mice; NG-Nitroarginine Methyl Ester; Nitric Oxide; Nitric Oxide Synthase; Pentylenetetrazole; Phosphodiesterase Inhibitors; Piperazines; Purines; Seizures; Sildenafil Citrate; Sulfones; Treatment Outcome | 2010 |
Maintained activity of glycogen synthase kinase-3beta despite of its phosphorylation at serine-9 in okadaic acid-induced neurodegenerative model.
Glycogen synthase kinase-3beta (GSK3beta) is recognized as one of major kinases to phosphorylate tau in Alzheimer's disease (AD), thus lots of AD drug discoveries target GSK3beta. However, the inactive form of GSK3beta which is phosphorylated at serine-9 is increased in AD brains. This is also inconsistent with phosphorylation status of other GSK3beta substrates, such as beta-catenin and collapsin response mediator protein-2 (CRMP2) since their phosphorylation is all increased in AD brains. Thus, we addressed this paradoxical condition of AD in rat neurons treated with okadaic acid (OA) which inhibits protein phosphatase-2A (PP2A) and induces tau hyperphosphorylation and cell death. Interestingly, OA also induces phosphorylation of GSK3beta at serine-9 and other substrates including tau, beta-catenin and CRMP2 like in AD brains. In this context, we observed that GSK3beta inhibitors such as lithium chloride and 6-bromoindirubin-3'-monoxime (6-BIO) reversed those phosphorylation events and protected neurons. These data suggest that GSK3beta may still have its kinase activity despite increase of its phosphorylation at serine-9 in AD brains at least in PP2A-compromised conditions and that GSK3beta inhibitors could be a valuable drug candidate in AD. Topics: Alzheimer Disease; Animals; Cells, Cultured; Disease Models, Animal; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Indoles; Lithium Chloride; Neurons; Okadaic Acid; Oximes; Phosphorylation; Protein Kinase Inhibitors; Protein Phosphatase 2; Rats; Serine | 2010 |
Agmatine enhances the anticonvulsant effect of lithium chloride on pentylenetetrazole-induced seizures in mice: Involvement of L-arginine/nitric oxide pathway.
After nearly 60years, lithium is still the mainstay in the treatment of mood disorders. In addition to its antimanic and antidepressant effects, lithium also has anticonvulsant properties. Similar to lithium, agmatine plays a protective role in the central nervous system against seizures and has been reported to enhance the effect of different antiepileptic agents. Moreover, both agmatine and lithium have modulatory effects on the L-arginine/nitric oxide pathway. This study was designed to investigate: (1) whether agmatine and lithium exert a synergistic effect against clonic seizures induced by pentylenetetrazole and (2) whether or not this synergistic effect is mediated through inhibition of the L-arginine/nitric oxide pathway. In our study, acute administration of a single potent dose of lithium chloride (30mg/kg ip) increased seizure threshold, whereas pretreatment with a low and independently noneffective dose of agmatine (3mg/kg) potentiated a subeffective dose of lithium (10mg/kg). N(G)-L-arginine methyl ester (L-NAME, nonspecific nitric oxide synthase inhibitor) at 1 and 5mg/kg and 7-nitroindazole (7-NI, preferential neuronal nitric oxide synthase inhibitor) at 15 and 30mg/kg augmented the anticonvulsant effect of the noneffective combination of lithium (10mg/kg ip) and agmatine (1mg/kg), whereas several doses (20 and 40mg/kg) of aminoguanidine (inducible nitric oxide synthase inhibitor) failed to alter the seizure threshold of the same combination. Furthermore, pretreatment with independently noneffective doses (30 and 60mg/kg) of L-arginine (substrate for nitric oxide synthase) inhibited the potentiating effect of agmatine (3mg/kg) on lithium (10mg/kg). Our findings demonstrate that agmatine and lithium chloride have synergistic anticonvulsant properties that may be mediated through the L-arginine/nitric oxide pathway. In addition, the role of constitutive nitric oxide synthase versus inducible nitric oxide synthase is prominent in this phenomenon. Topics: Agmatine; Analysis of Variance; Animals; Antidepressive Agents; Arginine; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Synergism; Enzyme Inhibitors; Indazoles; Lithium Chloride; Male; Mice; NG-Nitroarginine Methyl Ester; Nitric Oxide; Pentylenetetrazole; Seizures; Signal Transduction | 2010 |
Carbamazepine can induce kidney water absorption by increasing aquaporin 2 expression.
Carbamazepine (Carba) is an anticonvulsant and psychotropic drug used widely for the treatment of intellectual disability and severe pains, but the incidence of hyponatremia is a common related occurrence. This hyponatremia is frequently attributed to a SIADH induced by this drug. It is also known that Carba is used to decrease the urinary volume in Diabetes Insipidus (DI) because it has an antidiuretic effect. Lithium (Li) is one of the most important drugs used to treat bipolar mood disorders. However Li has the undesirable capacity to induce DI. Nowadays, the association of these drugs is used in the treatment of patients with psychiatric and neurological problems.. In vivo and in vitro (microperfusion) experiments were developed to investigate the effect of Carba in the rat Inner Medullary Collecting Duct (IMCD).. The results revealed that Carba was able to stimulate the V2 vasopressin receptor-Protein G complex increasing the (Pf) and water absorption. In vivo studies showed that in rats with lithium-induced DI, Carba decreased the urinary volume and increased the urinary osmolality. AQP2 expression was increased both in normal IMCD incubated with Carba and in IMCD from lithium-induced DI after Carba addition to the diet, when compared with the control.. These results showed that the hyponatremia observed in patients using this anticonvulsant drug, at least in part, is due to the Carba capacity to increase IMCD's Pf and that the Lithium-Carbamazepine association is beneficial to the patient. Topics: Absorption; Animals; Anticonvulsants; Aquaporin 2; Carbamazepine; Diabetes Insipidus; Disease Models, Animal; Hyponatremia; Kidney Tubules, Collecting; Lithium Chloride; Male; Rats; Rats, Wistar; Receptors, Vasopressin; Water | 2010 |
Effect of inhibition of glycogen synthase kinase-3 on cardiac hypertrophy during acute pressure overload.
Myocardial hypertrophy has been recognized to be an adaptive response to a variety of external stimuli (e.g., myocardial infarction, pressure overload, catecholamine treatment, endocrine disorders) that are involved in several subcellular factors that mediate signaling pathways, from external stimuli to nuclear protein synthesis. Glycogen synthase kinase-3beta (GSK-3beta) is one of the subcellular factors that regulate nuclear transcription factors, such as activated T-cell (NFAT) proteins, that are related to gene programming during cardiac hypertrophy. On the other hand, GSK-3beta, known as a regulator of cardiomyocyte growth in Wnt signaling of cardiogenesis, is involved in beta-catenin degradation. Inhibition of GSK-3beta has been reported to induce cardiac hypertrophy. Tateishi et al. demonstrated in an aortic constriction-induced acute hypertrophy model using 6-week-old Wister rats that if GSK-3b is inhibited by LiCl up-regulated beta-catenin expression and additional hypertrophy were observed. They suggested that Li(2+) had an additive effect on pressure overload-induced hypertrophy through the GSK-3beta-beta-catenin pathway. Their article provides promising information on the mechanism of hypertrophic myocyte growth during acute pressure overload. Topics: Animals; Aorta, Abdominal; Atrial Natriuretic Factor; beta Catenin; Blood Pressure; Cardiovascular Agents; Disease Models, Animal; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Hypertension; Hypertrophy, Left Ventricular; Ligation; Lithium Chloride; Phosphorylation; Protein Kinase Inhibitors; Rats; RNA, Messenger; Serine; Time Factors | 2010 |
Effect of inhibition of glycogen synthase kinase-3 on cardiac hypertrophy during acute pressure overload.
A large number of diverse signaling molecules in cell and animal models participate in the stimulus-response pathway through which the hypertrophic growth of the myocardium is controlled. However, the mechanisms of signaling pathway including the influence of lithium, which is known as an inhibitor of glycogen synthase kinase-3beta, in pressure overload hypertrophy remain unclear. The aim of our study was to determine whether glycogen synthase kinase-3beta inhibition by lithium has acute effects on the myocyte growth mechanism in a pressure overload rat model.. First, we created a rat model of acute pressure overload cardiac hypertrophy by abdominal aortic banding. Protein expression time courses for beta-catenin, glycogen synthase kinase-3beta, and phosphoserine9-glycogen synthase kinase-3beta were then examined. The rats were divided into four groups: normal rats with or without lithium administration and pressure-overloaded rats with or without lithium administration. Two days after surgery, Western blot analysis of beta-catenin, echo-cardiographic evaluation, left ventricular (LV) weight, and LV atrial natriuretic peptide mRNA levels were evaluated.. We observed an increase in the level of glycogen synthase kinase-3beta phosphorylation on Ser 9. A significant enhancement of LV heart weight (P < 0.05) and interventricular septum and posterior wall thickness (P < 0.05) with pressure-overloaded hypertrophy in animals treated with lithium were also observed. Atrial natriuretic peptide mRNA levels were significantly increased with pressure overload hypertrophy in animals treated with lithium.. We have shown in an animal model that inhibition of glycogen synthase kinase-3beta by lithium has an additive effect on pressure overload cardiac hypertrophy. Topics: Animals; Aorta, Abdominal; Atrial Natriuretic Factor; beta Catenin; Blood Pressure; Blotting, Western; Cardiovascular Agents; Disease Models, Animal; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Hypertension; Hypertrophy, Left Ventricular; Ligation; Lithium Chloride; Male; Phosphorylation; Polymerase Chain Reaction; Protein Kinase Inhibitors; Rats; Rats, Wistar; RNA, Messenger; Serine; Time Factors; Ultrasonography | 2010 |
Voltage-dependent calcium channel and NMDA receptor antagonists augment anticonvulsant effects of lithium chloride on pentylenetetrazole-induced clonic seizures in mice.
Although lithium is still a mainstay in the treatment of bipolar disorder, its underlying mechanisms of action have not been completely elucidated. Several studies have shown that lithium can also modulate seizure susceptibility in a variety of models. In the present study, using a model of clonic seizures induced with pentylenetetrazole (PTZ) in male Swiss mice, we investigated whether there is any interaction between lithium and either calcium channel blockers (CCBs: nifedipine, verapamil, and diltiazem) or N-methyl-D-aspartate (NMDA) receptor antagonists (ketamine and MK-801) in modulating seizure threshold. Acute lithium administration (5-100mg/kg, ip) significantly (P<0.01) increased seizure threshold. CCBs and NMDA receptor antagonists also exerted dose-dependent anticonvulsant effects on PTZ-induced seizures. Noneffective doses of CCBs (5mg/kg, ip), when combined with a noneffective dose of lithium (5mg/kg, ip), exerted significant anticonvulsant effects. Moreover, co-administration of a noneffective dose of either MK-801 (0.05mg/kg, ip) or ketamine (5mg/kg, ip) with a noneffective dose of lithium (5mg/kg, ip) significantly increased seizure threshold. Our findings demonstrate that lithium increases the clonic seizure threshold induced by PTZ in mice and interacts with either CCBs or NMDA receptor antagonists in exerting this effect, suggesting a role for Ca(2+) signaling in the anticonvulsant effects of lithium in the PTZ model of clonic seizures in mice. Topics: Analysis of Variance; Animals; Anticonvulsants; Calcium Channel Blockers; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Synergism; Excitatory Amino Acid Antagonists; Lithium Chloride; Male; Mice; Pentylenetetrazole; Seizures | 2010 |
Comorbidity between epilepsy and depression: experimental evidence for the involvement of serotonergic, glucocorticoid, and neuroinflammatory mechanisms.
Depression represents one of the most common comorbidities of temporal lobe epilepsy (TLE), and has profound negative impact on the quality of life of patients with TLE. However, causes and mechanisms of depression in TLE remain poorly understood, and effective therapies are lacking. We examined whether a commonly used model of TLE in rats could be used as a model of comorbidity between epilepsy and depression suitable for both mechanistic studies and for the development of mechanism-based antidepressant therapies. We established that animals that had been subjected to lithium chloride and pilocarpine status epilepticus (SE) and developed spontaneous recurrent seizures, exhibited a set of impairments congruent with a depressive state: behavioral equivalents of anhedonia and despair, dysregulation of the hypothalamus-pituitary-adrenal (HPA) axis, and compromised raphe-hippocampal serotonergic transmission. Pharmacologic studies have suggested that depressive impairments following SE develop as a result of enhanced interleukin-1beta signaling in the hippocampus, which leads to depression via inducing perturbations in the HPA axis and subsequent deficit in the raphe-hippocampal serotonergic transmission. Topics: Animals; Convulsants; Depressive Disorder; Disease Models, Animal; Epilepsy, Temporal Lobe; Hippocampus; Humans; Hypothalamo-Hypophyseal System; Interleukin-1beta; Lithium Chloride; Pilocarpine; Pituitary-Adrenal System; Raphe Nuclei; Rats; Receptors, Glucocorticoid; Serotonin; Signal Transduction; Status Epilepticus; Synaptic Transmission | 2010 |
Ketogenic diet exhibits neuroprotective effects in hippocampus but fails to prevent epileptogenesis in the lithium-pilocarpine model of mesial temporal lobe epilepsy in adult rats.
Although the number of antiepileptic drugs (AEDs) is increasing, none displays neuroprotective or antiepileptogenic properties that could prevent status epilepticus (SE)-induced drug-resistant epilepsy. Ketogenic diet (KD) and calorie restriction (CR) are proposed as alternative treatments in epilepsy. Our goal was to assess the neuroprotective or antiepileptogenic effect of these diets in a well-characterized model of mesial temporal lobe epilepsy following initial SE induced by lithium-pilocarpine in adult rats.. Seventy-five P50 male Wistar rats were fed a specific diet: normocalorie carbohydrate (NC), hypocalorie carbohydrate (HC), normocalorie ketogenic (NK), or hypocalorie ketogenic (HK). Rats were subjected to lithium-pilocarpine SE, except six NC to constitute a control group for histology (C). Four rats per group were implanted with epidural electrodes to record electroencephalography (EEG) during SE and the next six following days. From the seventh day, the animals were video-recorded 10 h daily to determine latency to epilepsy onset. Neuronal loss in hippocampus and parahippocampal cortices was analyzed 1 month after the first spontaneous seizure.. After lithium-pilocarpine injection, neither KD nor CR modified SE features or latency to epilepsy. In hippocampal layers, KD or CR exhibited a neuroprotective potential without cooperative effect. Parahippocampal cortices were not protected by the diets.. The antiepileptic effect of KD and/or CR is overwhelmed by lithium-pilocarpine injection. The isolated protection of hippocampal layers induced by KD or CR or their association failed to modify the course of epileptogenesis. Topics: Animals; Anticonvulsants; Caloric Restriction; Cerebral Cortex; Diet, Ketogenic; Dietary Carbohydrates; Disease Models, Animal; Drug Resistance; Electroencephalography; Epilepsy, Temporal Lobe; Hippocampus; Humans; Lithium Chloride; Male; Neuroprotective Agents; Pilocarpine; Rats; Rats, Wistar; Status Epilepticus | 2010 |
Folic acid administration prevents ouabain-induced hyperlocomotion and alterations in oxidative stress markers in the rat brain.
Bipolar disorder (BD) is a chronic, prevalent, and highly debilitating psychiatric illness. Folic acid has been shown to have antidepressant-like effects in preclinical and clinical studies and has also been suggested to play a role in BD. The present work investigates the therapeutic value of folic acid supplementation in a preclinical animal model of mania induced by ouabain.. Male Wistar rats were treated twice daily for seven days with folic acid (10, 50, and 100 mg/kg, p.o.) or the mood stabilizer lithium chloride (LiCl) (45 mg/kg, p.o.). One day after the last dose was given, the animals received an i.c.v. injection of ouabain (10 microM), a Na(+),K(+)-ATPase-inhibiting compound. Locomotor activity was assessed in the open-field test. Thiobarbituric acid-reactive substance (TBARS) levels, glutathione peroxidase (GPx), and glutathione reductase (GR) activities were measured in the cerebral cortex and hippocampus.. Ouabain (10 microM, i.c.v.) significantly increased motor activity in the open-field test, and seven days of pretreatment with folic acid (50 mg/kg, p.o.) or LiCl (45 mg/kg, p.o.) completely prevented this effect. Ouabain treatment elicited lipid peroxidation (increased TBARS levels) and reduced GPx activity in the hippocampus. GR activity was decreased in the cerebral cortex and hippocampus. These effects were prevented by pretreatment with folic acid and LiCl.. Our results show that folic acid, similarly to LiCl, produces a clear antimanic action and prevents the neurochemical alterations indicative of oxidative stress in an animal model of mania. Topics: Animals; Antimanic Agents; Biomarkers; Bipolar Disorder; Disease Models, Animal; Folic Acid; Hippocampus; Injections, Intraventricular; Lithium Chloride; Male; Motor Activity; Ouabain; Oxidative Stress; Rats; Rats, Wistar | 2010 |
Kainate-induced toxicity in the hippocampus: potential role of lithium.
We investigated the neuroprotective effects of lithium in an experimental neurodegeneration model gated to kainate (KA) receptor activation.. The hippocampus from KA-treated mice and hippocampal cell cultures were used to evaluate the pathways regulated by chronic lithium pretreatment in both in vivo and in vitro models.. Treatment with KA, as measured by fragmentation of alpha-spectrin and biochemically, induced the activation of calpain resulting in p35 cleavage to p25, indicating activation of cyclin-dependent kinase 5 (cdk5) and glycogen synthase kinase-3ss (GSK-3ss) and an increase in tau protein phosphorylation. Treatment with lithium reduced calpain activation and reduced the effects of cdk5 and GSK-3ss on tau. KA treatment of cultures resulted in neuronal demise. According to nuclear condensed cell counts, the addition of lithium to neuronal cell cultures (0.5-1 mM) a few days before KA treatment had neuroprotective and also antiapoptotic effects. The action of lithium on calpain/cdk5 and GSK-3ss pathways produced similar results in vivo. As calpain is activated by an increase in intracellular calcium, we showed that lithium reduced calcium concentrations in basal and KA-treated hippocampal cells, which was accompanied by an increase in NCX3, a Na+/Ca2+ exchanger pump.. A robust neuroprotective effect of lithium in the excitotoxic process induced by KA in mouse hippocampus was demonstrated via modulation of calcium entry and the subsequent inhibition of the calpain pathway. These mechanisms may act in an additive way with other mechanisms previously described for lithium, suggesting that it may be useful as a possible therapeutic strategy for Alzheimer's disease. Topics: Animals; Calcium; Calpain; Cell Survival; Cells, Cultured; Cyclin-Dependent Kinase 5; Disease Models, Animal; Glycogen Synthase Kinases; Hippocampus; Kainic Acid; Lithium Chloride; Male; Mice; Mice, Inbred Strains; Neurodegenerative Diseases; Neuroprotective Agents; Phosphorylation; tau Proteins | 2010 |
Time course of neuronal damage in the hippocampus following lithium-pilocarpine status epilepticus in 12-day-old rats.
Status epilepticus (SE) leads to serious damage in hippocampus of the adult brain. Much less is known about immature brain where neuronal degeneration may have different localization and time course. Lithium-pilocarpine SE was induced in 12-day-old male Wistar rats. Six different intervals after SE (from 4 h to 1 week) were studied using Fluoro-Jade B staining. Three to four animals were used for every interval. Severity of damage in individual parts of hippocampal formation was semi-quantified. A consistent neuronal damage occurred in all hippocampal fields (CA 1, CA 3, dentate gyrus) at all survival intervals. Hippocampal fields CA 1 and CA 3 exhibited degeneration of interneurons located mainly in stratum oriens and pyramidale at shorter intervals (4-12h). Massive degeneration of pyramidal cells started at 24h in CA 1 and at 48 h in CA 3. Dentate gyrus exhibited degenerating neurons in granular layer with a peak at short intervals (4-8 h), and molecular layer was spared. The lower blade of dentate gyrus was more affected than the upper blade. Damage of hilar neurons was negligible. Our results demonstrate that SE elicited in immature rats causes acute neurodegeneration in the hippocampus. Time course of this degeneration is different for individual parts of hippocampal formation and for individual cell types. Topics: Animals; Animals, Newborn; Dentate Gyrus; Disease Models, Animal; Hippocampus; Lithium Chloride; Male; Nerve Degeneration; Pilocarpine; Pyramidal Cells; Rats; Rats, Wistar; Status Epilepticus; Time Factors | 2010 |
Inverse agonism of cannabinoid CB1 receptors potentiates LiCl-induced nausea in the conditioned gaping model in rats.
Cannabinoid CB(1) receptor antagonists/inverse agonists, potentiate toxin-induced nausea and vomiting in animal models. Here, we sought to determine if this potentiated nausea was mediated by inverse agonism or neutral antagonism of the CB(1) receptor, and if the potentiated nausea would be produced by intracerebroventricular (icv) administration of an inverse agonist.. The conditioned gaping model of nausea in rats was used to compare the CB(1) receptor antagonist/inverse agonist, AM251, and the CB(1) receptor neutral antagonists, AM6527 (centrally and peripherally active) and AM6545 (peripherally active), in potentiating conditioned gaping produced by lithium chloride (LiCl) solution. The effect of icv (lateral ventricle and 4th ventricle) administration of AM251 on LiCl-induced gaping in this model was also evaluated.. At a dose that did not produce conditioned gaping on its own, systemically administered AM251 (1.25 mg.kg(-1)) potentiated LiCl-induced conditioned gaping and reduced sucrose palatability; however, even doses as high as 8 mg.kg(-1) of AM6545 and AM6527 neither potentiated LiCl-induced conditioned gaping nor reduced sucrose palatability. Infusions of AM251 into the lateral ventricles (1.25, 12.5 and 125 microg) or the 4th ventricle (2.5, 12.5 and 125 microg) did not potentiate LiCl-induced conditioned gaping reactions, but all doses attenuated saccharin palatability during the subsequent test.. Inverse agonism, but not neutral antagonism, of CB(1) receptors potentiated toxin-induced nausea. This effect may be peripherally mediated or may be mediated centrally by action on CB(1) receptors, located distal to the cerebral ventricles. Topics: Administration, Oral; Animals; Brain; Conditioning, Classical; Disease Models, Animal; Dose-Response Relationship, Drug; Feeding Behavior; Lithium Chloride; Male; Morpholines; Nausea; Piperidines; Pyrazoles; Rats; Rats, Sprague-Dawley; Receptor, Cannabinoid, CB1; Saccharin | 2010 |
Changes in the numbers and distribution of calretinin in the epileptic rat hippocampus.
To examine calretinin (CR)-containingObjectives: To examine cairetinin (CR)-containingnterneuronsthatdegenerate inthe hippocampus in post statusinterneurons that dege nera te in the hippocampusepilepticus (SE) ratsatdifferent time in post status epilepticus (SE) rats at different time points.. This study was conducted at the Central South University, Xiangya Hospital, Hunan Province, P.R. China between September 2008 and January 2010. Pilocarpine-induced SE was chosen as a model to generate chronic epileptic rats. To determine whether hippocampal neuronal populations are affected by hippocampal seizures, immunohistochemical assays were performed in brain sections obtained from age-matched control (n=50) and epileptic rats (n=170). Nissl stain was used to observe pathological changes of the hippocampus.. Our results revealed the most dramatic cell loss to be in the hilar, cornu Ammonis (CA)1, and CA3 areas in the epileptic rats. Quantitative analysis revealed significant differences between control and epileptic rats in the number of CR-positive interneurons. These interneurons were distributed in the hilar, CA1, and CA3 areas and in thedentate gyrus of both control and epileptic rats, but was more numerous in the hippocampus of normal rats. However, a transient increase of CR-positive interneurons was observed in the CA1 between 7 and 15 days post SE. The CR interneurons were mostly located in the hilar and CA1 for epileptic rats, and in the hilus for control rats.. Our data suggest that a different proportion of inhibitory interneurons was observed in the epileptic rat hippocampus, as their numbers differ from controls. These results indicate that the inhibitory circuits in the hippocampus may represent a compensatory response with a role to balance the enhanced excitatory input in the region. Topics: Analysis of Variance; Animals; Calbindin 2; Disease Models, Animal; Epilepsy; Gene Expression Regulation; Hippocampus; Interneurons; Lithium Chloride; Male; Pilocarpine; Rats; Rats, Sprague-Dawley; S100 Calcium Binding Protein G; Time Factors | 2010 |
Astroglial loss and edema formation in the rat piriform cortex and hippocampus following pilocarpine-induced status epilepticus.
In the present study we analyzed aquaporin-4 (AQP4) immunoreactivity in the piriform cortex (PC) and the hippocampus of pilocarpine-induced rat epilepsy model to elucidate the roles of AQP4 in brain edema following status epilepticus (SE). In non-SE-induced animals, AQP4 immunoreactivity was diffusely detected in the PC and the hippocampus. AQP4 immunoreactivity was mainly observed in the endfeet of astrocytes. Following SE the AQP4-deleted area was clearly detected in the PC, not in the hippocampus. Decreases in dystrophin and α-syntrophin immunoreactivities were followed by reduction in AQP4 immunoreactivity. These alterations were accompanied by the development of vasogenic edema and the astroglial loss in the PC. In addition, acetazolamide (an AQP4 inhibitor) treatment exacerbated vasogenic edema and astroglial loss both in the PC and in the hippocampus. These findings suggest that SE may induce impairments of astroglial AQP4 functions via disruption of the dystrophin/α-syntrophin complex that worsen vasogenic edema. Subsequently, vasogenic edema results in extensive astroglial loss that may aggravate vasogenic edema. Topics: Animals; Aquaporin 4; Astrocytes; Brain Edema; Calcium-Binding Proteins; Cell Count; Cerebral Cortex; Disease Models, Animal; Dystrophin; Gene Expression Regulation; Glial Fibrillary Acidic Protein; Hippocampus; Lithium Chloride; Male; Membrane Proteins; Muscle Proteins; Pilocarpine; Rats; Rats, Sprague-Dawley; Status Epilepticus | 2010 |
Expression and localization of annexin A7 in the rat lithium-pilocarpine model of acquired epilepsy.
Annexin A7 (synexin, ANXA7) is a member of annexins, which plays an essential role in the regulation of calcium homeostasis. Considerable evidence shows that the pathogenetic mechanism of acquired epilepsy (AE) has been related to the imbalance of calcium homeostasis. The aim of this study was to investigate ANXA7 expression and cellular localization in the cortex and hippocampus in the rat lithium-pilocarpine model of AE.. Totally 81 adult healthy male Wistar rats were randomly divided into control group (n = 9) and experimental group (n = 72), the experimental group contained eight subgroups according to sacrifice time (n = 9) (6-hour, 24-hour, 48-hour, 72-hour, 7-day, 15-day, 1-month, and 2-month). In the experimental group, rats were intraperitoneally injected by lithium-pilocarpine to induce AE model. We examined the expression and localization of ANXA7 via immunohistochemistry, double-label immunofluorescence with the use of neuron specific enolase (NSE) antibody, glial fibrillary acidic protein (GFAP) antibody and propidium iodide (PI), respectively. The data of optical density value were analyzed by analysis of variance.. ANXA7 expression increased significantly in the experimental groups especially in the acute period (6 hours, 24 hours, and 48 hours after the onset of seizure) using immunohistochemistry. Double-label immunofluorescence and confocal microscopy disclosed that ANXA7 localized in the neurons but not in astrocytes and did not localize in the nucleus, which were performed with anti-NSE, anti-GFAP and PI respectively.. ANXA7 may play a potential role in the pathogenetic mechanisms of the rat lithium-pilocarpine model of AE. Topics: Animals; Annexin A7; Calcium; Cerebral Cortex; Disease Models, Animal; Fluorescent Antibody Technique; Hippocampus; Immunohistochemistry; Lithium Chloride; Male; Pilocarpine; Rats; Rats, Wistar; Status Epilepticus | 2010 |
Differential fate and functional outcome of lithium chloride primed adult neural progenitor cell transplants in a rat model of Huntington disease.
The ability to predetermine the fate of transplanted neural progenitor cells (NPCs) and specifically to direct their maturation has the potential to enhance the efficiency of cell-transplantation therapy for neurodegenerative disease. We previously demonstrated that transient exposure of subventricular zone (SVZ)-derived adult NPCs to lithium chloride during in vitro proliferation alters differential fate in vitro and increases the proportion of cells expressing neuronal markers while reducing glial progeny. To extend these findings, we examined whether in vitro priming of adult SVZ-derived NPCs with lithium chloride before transplantation into the quinolinic acid (QA) lesion rat model of Huntington disease altered in vivo neuronal differentiation and sensorimotor function compared with nonprimed NPC transplants.. NPCs were isolated from the SVZ of the adult rat brain and cultured for 2 weeks. Four days before transplantation into the QA-lesioned rat striatum, the cells were labeled with BrdU and primed with lithium chloride. The rats underwent regular evaluation of forelimb use and sensorimotor neglect to establish functional effects of NPC transplantation. Twelve weeks after transplantation, the brains were analyzed with immunohistochemistry to compare the differential fate of primed and nonprimed NPCs.. We observed that in vitro priming of adult NPCs with lithium chloride reduced gliogenesis and enhanced the occurrence of DARPP-32-positive neurons when compared with nonprimed cells 12 weeks after transplantation into the QA-lesioned striatum. Lithium chloride priming also augmented the formation of efferent projections from newly formed neurons in the damaged host striatum to the globus pallidus. This was associated with acceleration of sensorimotor function recovery in rats receiving transplants of lithium chloride-primed adult NPCs compared with nonprimed transplants.. These initial findings indicate that in vitro priming of adult NPCs with lithium chloride may augment transplant efficiency and accelerate sensorimotor function outcome in vivo. Topics: Adjuvants, Immunologic; Adult Stem Cells; Animals; Brain; Cell Movement; Cell Survival; Cell- and Tissue-Based Therapy; Cells, Cultured; Disease Models, Animal; Dopamine and cAMP-Regulated Phosphoprotein 32; Huntington Disease; Lithium Chloride; Male; Neural Stem Cells; Neurogenesis; Rats; Rats, Wistar; SOXB1 Transcription Factors | 2010 |
Suppression of Plasmodium berghei parasitemia by LiCl in an animal infection model.
Malaria, caused by the Plasmodium parasite is still a health problem worldwide due to resistance of the pathogen to current anti-malarials. The search for new anti-malarial agents has become more crucial with the emergence of chloroquine-resistant Plasmodium falciparum strains. Protein kinases such as mitogen-activated protein kinase (MAPK), MAPK kinase, cyclin-dependent kinase (CDK) and glycogen synthase kinase- 3(GSK-3) of parasitic protozoa are potential drug targets. GSK-3 is an enzyme that plays a vital role in multiple cellular processes, and has been linked to pathogenesis of several diseases such as type II diabetes and Alzheimer's disease. In the present study, the antiplasmodial property of LiCl, a known GSK-3 inhibitor, was evaluated in vivo for its antimalarial effect against mice infected with Plasmodium berghei. Infected ICR mice were intraperitoneally administered with LiCl for four consecutive days before (prophylactic test) and after (suppressive test) inoculation of P. berghei-parasitised erythrocytes. Results from the suppressive test (post-infection LiCl treatment) showed inhibition of erythrocytic parasitemia development by 62.06%, 85.67% and 85.18% as compared to nontreated controls for the 100 mg/kg, 300 mg/kg and 600 mg/kg dosages respectively. Both 300 mg/kg and 600 mg/kg LiCl showed similar significant (P<0.05) suppressive values to that obtained with chloroquine-treated mice (86% suppression). The prophylactic test indicated a significantly (P<0.05) high protective effect on mice pre-treated with LiCl with suppression levels relatively comparable to chloroquine (84.07% and 86.26% suppression for the 300 mg/kg and 600 mg/kg LiCl dosages respectively versus 92.86% suppression by chloroquine). In both the suppressive and prophylactic tests, LiCl-treated animals survived longer than their non-treated counterparts. Mortality of the non-treated mice was 100% within 6 to 7 days of parasite inoculation whereas mice administered with LiCl survived beyond 9 days. Healthy non-infected mice administered with 600 mg/ kg LiCl for four consecutive days also showed decreased mortality compared to animals receiving lower doses of LiCl; three of the seven mice intraperitoneally injected with the former dose of LiCl did not survive more than 24 h after administration of LiCl whereas animals given the lower LiCl doses survived beyond four days of LiCl administration. To date, no direct evidence of anti-malarial activity in vivo or in vitro has been Topics: Animals; Antimalarials; Chemoprevention; Chloroquine; Disease Models, Animal; Glycogen Synthase Kinase 3; Lithium Chloride; Malaria; Male; Mice; Mice, Inbred ICR; Parasitemia; Plasmodium berghei; Survival Analysis; Treatment Outcome | 2010 |
Status epilepticus produces chronic alterations in cardiac sympathovagal balance.
Status epilepticus (SE) activates the autonomic nervous system, increasing sympathetic nervous system control of cardiac function during seizure activity. However, lasting effects of SE on autonomic regulation of the heart, which may contribute to mortality following seizure activity, are unknown. Therefore, autonomic control of cardiac function was assessed following SE.. Using Sprague-Dawley rats after 1-2 weeks of recovery from lithium-pilocarpine-induced SE or control procedures, we tested overall sympathovagal control of the heart, the individual contributions of the sympathetic and parasympathetic components of the autonomic nervous system, and baroreflex sensitivity.. SE induced a chronic shift in sympathovagal balance toward sympathetic dominance resulting from decreased parasympathetic activity. Baroreflex sensitivity to increased blood pressure was also decreased, likely resulting from diminished vagal activation.. Chronic alterations in autonomic regulation of cardiac function, characterized by increased sympathetic dominance, occur following SE and likely contribute to subsequent increased cardiac risk and mortality. Topics: Analysis of Variance; Animals; Atropine; Baroreflex; Blood Pressure; Disease Models, Animal; Heart Rate; Lithium Chloride; Male; Muscarinic Antagonists; Pilocarpine; Rats; Rats, Sprague-Dawley; Status Epilepticus; Sympathetic Nervous System; Time Factors; Vagus Nerve | 2009 |
Glutamate receptors as targets of protein kinase C in the pathophysiology and treatment of animal models of mania.
Considerable biochemical evidence suggests that the protein kinase C (PKC) signaling cascade may be a convergent point for the actions of anti-manic agents, and that excessive PKC activation can disrupt prefrontal cortical regulation of thinking and behavior. To date, however, brain protein targets of PKC's anti-manic effects have not been fully identified. Here we showed that PKC activity was enhanced in the prefrontal cortex of animals treated with the psychostimulant amphetamine. Phosphorylation of MARCKS, a marker of PKC activity, was increased in the prefrontal cortex of animals treated with the psychostimulant amphetamine, as well as in sleep-deprived animals (another animal model of mania), but decreased in lithium-treated animals. The antidepressant imipramine, which shows pro-manic properties in patients with bipolar disorder (BPD), also enhanced phospho-MARCKS in prefrontal cortex in vivo. We further explored the functional targets of PKC in mania-associated behaviors. Neurogranin is a brain-specific, postsynaptically located PKC substrate. PKC phosphorylation of neurogranin was robustly increased by pro-manic manipulations and decreased by anti-manic agents. PKC phosphorylation of the NMDA receptor site GluN1S896 and the AMPA receptor site GluA1T840 was also enhanced in the prefrontal cortex of animals treated with the antidepressant imipramine, as well as in behaviorally sleep-deprived animals, in striking contrast to the reduced activity seen in lithium-treated animals. These results suggest that PKC may play an important role in regulating NMDA and AMPA receptor functions. The biochemical profile of the PKC pathway thus encompasses both pro- and anti-manic effects on behavior. These results suggest that PKC modulators or their intracellular targets may ultimately represent novel avenues for the development of new therapeutics for mood disorders. Topics: Amphetamine; Animals; Antidepressive Agents, Tricyclic; Bipolar Disorder; Cell Membrane; Central Nervous System Stimulants; Disease Models, Animal; Imipramine; Intracellular Signaling Peptides and Proteins; Lithium Chloride; Male; Membrane Proteins; Mice; Mice, Inbred C57BL; Myristoylated Alanine-Rich C Kinase Substrate; Neurogranin; Phosphorylation; Prefrontal Cortex; Protein Kinase C; Rats; Rats, Inbred WKY; Receptors, Glutamate; Sleep Deprivation | 2009 |
Induction of the Wnt antagonist, Dickkopf-1, contributes to the development of neuronal death in models of brain focal ischemia.
Inhibition of the canonical Wnt pathway has been implicated in the pathophysiology of neuronal death. Here, we report that the secreted Wnt antagonist, Dickkopf-1 (Dkk-1) is rapidly induced in neurons after induction of focal brain ischemia. In rats undergoing transient focal ischemia in response to brain infusion of endothelin-1, Dkk-1 was induced in neurons of the ischemic core and the penumbra region. Induction of Dkk-1 was associated with a reduced expression of beta-catenin (a downstream signaling molecule of the canonical Wnt pathway), and was not observed in neurons expressing the protective protein, heat shock protein-70. Treatment with lithium ions, which, inter alia, rescue the canonical Wnt pathway, was highly protective against ischemic damage. Dkk-1 was also induced in cortical neurons of mice undergoing permanent middle cerebral artery (MCA) occlusion. This model allowed us to compare wild-type mice with doubleridge mice, which are characterized by a reduced expression of Dkk-1. Doubleridge mice showed an attenuated reduction of beta-catenin and a reduced infarct volume in response to MCA occlusion, providing a direct demonstration that Dkk-1 contributes to the pathophysiology of ischemic neuronal damage. These data rise the interesting possibility that Dkk-1 antagonists or drugs that rescue the Wnt pathway might be neuroprotective in stroke. Topics: Animals; beta Catenin; Brain Ischemia; Cell Death; Cerebral Arteries; Disease Models, Animal; Endothelin-1; Infusions, Intra-Arterial; Intercellular Signaling Peptides and Proteins; Lithium Chloride; Male; Mice; Mice, Inbred C3H; Mice, Transgenic; Rats; Wnt Proteins | 2009 |
Glycogen synthase kinase-3beta (GSK3beta) inhibition suppresses the inflammatory response to Francisella infection and protects against tularemia in mice.
Francisella tularensis, the causative agent of tularemia, is currently considered a category A bioterrorism agent due to its high virulence. Infection with F. tularensis results in an inflammatory response that plays an important role in the pathogenesis of the disease; however, the cellular mechanisms regulating this response are poorly understood. Glycogen synthase kinase-3beta (GSK3beta) is a serine/threonine protein kinase that has recently emerged as a key regulatory switch in the modulation of the inflammatory response. In this study, we investigated the effect of GSK3beta inhibition in regulating F. tularensis LVS-induced inflammatory responses. F. tularensis LVS infection of murine peritoneal macrophages induced a TLR2 dependent phosphorylation of GSK3beta. Inhibition of GSK3beta resulted in a significant decrease in the production of pro-inflammatory cytokine IL-6, IL-12p40 and TNF-alpha, as well as a significant increase in the production of the anti-inflammatory cytokine IL-10. GSK3beta regulated the F. tularensis LVS-induced cytokine response by differentially affecting the activation of transcription factors NF-kappaB and CREB. Inhibition of GSK3beta by lithium in vivo suppressed the inflammatory response in mice infected with F. tularensis LVS and conferred a survival advantage. In addition, we show that the production of IFN-gamma contributed to the development of tularemia and to the fatal outcome of the infected animals, depending on the timing and the relative level of the IFN-gamma produced. IFN-gamma potentiated F. tularensis LVS-induced cytokine production by increasing GSK3beta activity and the nuclear translocation of NF-kappaB. Taken together, these results demonstrate a regulatory function of GSK3beta in modulating inflammatory responses that can be detrimental to the host during an F. tularensis LVS infection, and suggest that inhibition of GSK3beta may represent a novel therapeutic approach in the treatment of tularemia. Topics: Animals; Cells, Cultured; Cyclic AMP Response Element-Binding Protein; Disease Models, Animal; Female; Francisella tularensis; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Interleukin-10; Interleukin-12 Subunit p40; Interleukin-6; Lithium Chloride; Macrophages, Peritoneal; Mice; Mice, Inbred C57BL; Mice, Knockout; NF-kappa B; Phosphorylation; Toll-Like Receptor 2; Tularemia; Tumor Necrosis Factor-alpha | 2009 |
Evidence of calpain/cdk5 pathway inhibition by lithium in 3-nitropropionic acid toxicity in vivo and in vitro.
Lithium reduced striatal neurodegeneration induced in rats by 3-nitropropionic acid inhibiting calpain activation. Lithium prevented an increase in cdk5 activity, as shown by the levels of the co-activator p35. Myocite enhancer factor 2 (MEF2), a downstream substrate for cdk5 with pro-survival activity, showed increased phosphorylation. In primary cultures of neurons treated with 3-NP, lithium also reduced protease activity mediated by calpain, cdk5 activation and cellular death. These observations indicate that lithium has a neuroprotective effect. Lithium treatment also reduced the intracellular increase in calcium induced by 3-NP. The finding that lithium mediates the modulation of the calpain/cdk5 pathway further supports its use in the treatment of neurodegenerative diseases. Topics: Animals; Calcium; Calpain; Cell Survival; Cells, Cultured; Cyclin-Dependent Kinase 5; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Interactions; Embryo, Mammalian; Gene Expression Regulation; Hippocampus; Huntington Disease; Lithium Chloride; Male; Mice; Neurons; Neuroprotective Agents; Nitro Compounds; Propionates; Rats; Rats, Sprague-Dawley; Signal Transduction; Succinate Dehydrogenase | 2009 |
Elevated glycogen synthase kinase-3 activity in Fragile X mice: key metabolic regulator with evidence for treatment potential.
Significant advances have been made in understanding the underlying defects of and developing potential treatments for Fragile X syndrome (FXS), the most common heritable mental retardation. It has been shown that neuronal metabotropic glutamate receptor 5 (mGluR5)-mediated signaling is affected in FX animal models, with consequent alterations in activity-dependent protein translation and synaptic spine functionality. We demonstrate here that a central metabolic regulatory enzyme, glycogen synthase kinase-3 (GSK3) is present in a form indicating elevated activity in several regions of the FX mouse brain. Furthermore, we show that selective GSK3 inhibitors, as well as lithium, are able to revert mutant phenotypes of the FX mouse. Lithium, in particular, remained effective with chronic administration, although its effects were reversible even when given from birth. The combination of an mGluR5 antagonist and GSK3 inhibitors was not additive. Instead, it was discovered that mGluR5 signaling and GSK3 activation in the FX mouse are coordinately elevated, with inhibition of mGluR5 leading to inhibition of GSK3. These findings raise the possibility that GSK3 is a fundamental and central component of FXS pathology, with a substantial treatment potential. Topics: Acoustic Stimulation; Analysis of Variance; Animals; Antimanic Agents; Brain; Citrates; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Administration Routes; Enzyme Inhibitors; Excitatory Amino Acid Antagonists; Exploratory Behavior; Fragile X Mental Retardation Protein; Gene Expression Regulation; Glycogen Synthase Kinase 3; Indoles; Lithium Chloride; Male; Maleimides; Mice; Mice, Knockout; Pyridines; Seizures; Serine; Thiazoles; Urea | 2009 |
Fenofibrate, a peroxisome proliferator-activated receptor-alpha agonist, exerts anticonvulsive properties.
The underlying mechanisms of the ketogenic diet (KD) remain unknown. Involvement of peroxisome proliferator-activated receptor-alpha (PPARalpha) has been suggested. The aim of this study was to assess the anticonvulsant properties of fenofibrate, a PPARalpha agonist. Wistar rats were fed at libitum during 14 days by regular diet, KD, regular diet containing 0.2% fenofibrate (F), or KD containing 0.2% fenofibrate (KD + F). Pentylenetetrazol (PTZ) threshold and latencies to the onset of status epilepticus induced by lithium-pilocarpine were used to assess diet treatments with anticonvulsive effects. Myoclonic and generalized seizure PTZ thresholds were increased in F- and KD-treated animals in comparison to control. No difference was observed between KD + F group and the others groups (control, F, KD). Latencies to the onset of status epilepticus were increased in F and KD groups compared to control. Fenofibrate exerts anticonvulsive properties comparable to KD in adult rats using PTZ and lithium-pilocarpine models. The underlying mechanisms such as PPARalpha activation and others should be investigated. These findings may provide insights into future directions to simplify KD protocols. Topics: 3-Hydroxybutyric Acid; Analysis of Variance; Animals; Body Weight; Diet, Ketogenic; Disease Models, Animal; Electroencephalography; Epilepsy; Fenofibrate; Hypolipidemic Agents; Ketone Bodies; Lithium Chloride; Liver; Male; Organ Size; Pentylenetetrazole; Pilocarpine; PPAR alpha; Rats; Rats, Wistar; Reaction Time | 2009 |
Complex time-dependent alterations in the brain expression of different drug efflux transporter genes after status epilepticus.
Frequent epileptic seizures or prolonged seizure activity (status epilepticus, SE) is known to increase the brain expression of drug efflux transporter genes and proteins, such as P-glycoprotein (Pgp) and members of the multidrug resistance protein (MRP) family, which might reduce brain levels of antiepileptic drugs and, therefore, be involved in drug resistance. However, the time course of alterations in Pgp or MRPs after seizures or SE is only incompletely known.. This prompted us to study the time course of alterations in the expression of different efflux transporter genes (Mdr1a, Mdr1b, MRP1, MRP2, MRP5) at various times after a pilocarpine-induced SE in limbic brain regions, using quantitative real-time polymerase chain reaction (RT-PCR) (qPCR).. Unexpectedly, between 6 and 24 h after onset of SE, genes encoding Pgp (Mdr1a, Mdr1b), Mrp1, and Mrp5 were downregulated in hippocampus, amygdala, or piriform cortex. This initial decrease in expression was followed by normalization and then increased expression, which became maximal 2 days after SE. One explanation for the initial decrease in transporter expression could be SE-induced acute inflammatory processes, because proinflammatory cytokines are known to suppress the expression of Pgp and other efflux transporters. To directly address this possibility, we quantified the hippocampal mRNA expression of interleukin-1beta, interleukin-6, and tumor necrosis factor-alpha, showing a marked SE-induced increase in these cytokines, which paralleled the decreased expression of efflux transporters.. Taken together, these findings indicate that alterations in expression of drug efflux transporters after prolonged seizure activity are more complex than previously thought. Topics: Analysis of Variance; Animals; ATP Binding Cassette Transporter, Subfamily B, Member 1; Brain; Cyclooxygenase 2; Cytokines; Disease Models, Animal; Female; Gene Expression Regulation; Lithium Chloride; Multidrug Resistance-Associated Proteins; Pilocarpine; Rats; Rats, Wistar; RNA, Messenger; Status Epilepticus; Time Factors | 2009 |
Lipopolysaccharide (LPS) blocks the acquisition of LiCl-induced gaping in a rodent model of anticipatory nausea.
The effects of systemic treatment with lipopolysaccharide (LPS) on conditioned gaping in a rodent model of anticipatory nausea were examined. Stimulation of the immune system has been found to enhance, impair, or have no effect on various learning and memory tasks. The development of anticipatory nausea is formed through a classically conditioned response to a context that has been paired previously with toxin-induced nausea and/or vomiting. Rats display a distinctive conditioned gaping response when injected with a nausea-inducing drug such as LiCl. In the present study, male Long-Evans rats were injected intraperitoneally with LPS (200microg/kg) or saline (NaCl) followed 90min later by an injection of the toxin LiCl or saline before being placed in a distinctive context on four conditioning days (72h apart). On the condition test day, rats (n=6/group) were placed in the distinctive context in a drug-free state and behavioral responses were videotaped. Rats given LPS followed by LiCl were found to have significantly fewer gaping responses when compared to rats given NaCl followed by LiCl. All groups were also found to have similar levels of spontaneous ingestive behaviors suggesting that the decrease in gaping was not due to motor impairment. The present results suggest that activation of the immune system with LPS administration significantly impairs the acquisition of anticipatory nausea. Topics: Animals; Association Learning; Conditioning, Psychological; Disease Models, Animal; Immune System Phenomena; Lipopolysaccharides; Lithium Chloride; Male; Memory; Memory Disorders; Nausea; Pons; Rats; Rats, Long-Evans; Vomiting, Anticipatory | 2009 |
Insidious weight gain in prepubertal seized rats treated with an atypical neuroleptic: the role of food consumption, fluid consumption, and spontaneous ambulatory activity.
Extreme obesity slowly develops in female rats over the months following seizures induced by a single systemic injection of lithium and pilocarpine if the resulting limbic seizures are treated with the atypical neuroleptic acepromazine (but not with ketamine). To discern the contributions from food consumption, water consumption, and (daytime and nighttime) activity to this weight gain, these behaviors were monitored for 4 months, about 2 months after seizure induction. The results indicated that the rats that underwent the obesity procedure exhibited 50% heavier body weights and consumed 42% more food than the reference group, which included rats that had been induced to seize but treated with ketamine. There were no statistically significant differences between groups with respect to either water consumption or (daytime or nighttime) activity. Factor analyses of data for individual rats verified the dissociation between activity and weight gain for the obese rats. The results suggest that the progressive weight gains are centrally mediated and are not secondary to diminished activity or altered fluid consumption. Topics: Acepromazine; Analysis of Variance; Animals; Antipsychotic Agents; Body Weight; Disease Models, Animal; Drinking; Eating; Epilepsy; Female; Lithium Chloride; Obesity; Pilocarpine; Rats; Rats, Wistar; Weight Gain | 2009 |
Longitudinal microPET imaging of brain glucose metabolism in rat lithium-pilocarpine model of epilepsy.
The lithium-pilocarpine model of epilepsy in rat has been used extensively to investigate basic mechanisms of epilepsy and mimics human temporal lobe epilepsy. Our aim was to investigate longitudinal alterations in metabolism after lithium-pilocarpine induced status epilepticus (SE) using [(18)F]FDG microPET. Twenty-eight Wistar rats received lithium chloride followed by pilocarpine (n=19) or saline (n=9) IP. Continuous video-EEG was used to monitor SE and occurrence of spontaneous seizures (SS). FDG microPET imaging was performed at baseline, on day 3 after drug administration (D3), and at the end of the monitoring period (CR). MicroPET images were spatially normalized to Paxinos space and parametric standardized uptake value (SUV)-images were generated. Metabolism was compared between groups of animals and between different time points. Eighteen animals developed SE, 11 had died by D3. SS were recorded in 3 of 7 surviving SE animals. On D3, metabolism was reduced in SE group compared to controls throughout the brain (-49+/-27%), except for the cerebellum: mostly in hippocampus, entorhinal cortex and thalamus bilaterally. Metabolism tended to be different between SS and no SS animals on D3 in striatum and hippocampus. In CR condition, relative metabolism was significantly different in SE group compared to controls in cerebellum and brainstem bilaterally and left striatum and entorhinal cortex. There were no significant differences between SS and no SS animals in CR condition. Pilocarpine-induced SE causes a severe, but transient reduction in overall metabolism on D3 in rat brain. Metabolic differences on D3 between SS and no SS animals need further study to investigate potential use as an early marker of epileptogenesis. Topics: Animals; Brain; Brain Mapping; Disease Models, Animal; Electroencephalography; Epilepsy; Fluorodeoxyglucose F18; Glucose; Lithium Chloride; Male; Pilocarpine; Positron-Emission Tomography; Rats; Rats, Wistar | 2009 |
Large differences in blood measures, tissue weights, and focal areas of damage 1 year after postseizure treatment with acepromazine or ketamine.
Approximately 1 year after rats were seized as young adults with lithium (3 mEq/kg) and pilocarpine (30 mg/kg) and given acepromazine or ketamine, 18 blood measures, wet tissue weights, and detailed damage scores for 107 brain structures were completed. Compared with normal and ketamine-treated rats, acepromazine-treated seized rats (total n=54) had lighter pancreata and spleens and elevated aspartate aminotransferase and alanine aminotransferase blood levels. Even though average damage did not differ, the mosaic of brain damage completely discriminated the two seized groups. Differential effects of postseizure treatment on functions of the thyroid, pancreas, and spleen were indicated. Ketamine-treated seized rats were healthier than acepromazine-treated seized rats or normal rats. This experiment demonstrates the importance of whole-organism assessment and that the single administration of a specific drug after onset of status epilepticus can produce marked differences in the evolution of brain damage and its influence on specific organs for the rest of the animal's life. Topics: Acepromazine; Analysis of Variance; Animals; Blood Pressure; Brain; Disease Models, Animal; Dopamine Antagonists; Excitatory Amino Acid Antagonists; Female; Ketamine; Lithium Chloride; Longitudinal Studies; Male; Neurologic Examination; Organ Size; Pilocarpine; Rats; Rats, Wistar; Seizures; Statistics as Topic; Thyroid Gland | 2009 |
Elevated plasma corticosterone level and depressive behavior in experimental temporal lobe epilepsy.
Depression is frequently reported in epilepsy patients; however, mechanisms of co-morbidity between epilepsy and depression are poorly understood. An important mechanism of depression is disinhibition within the hypothalamo-pituitary-adrenocortical (HPA) axis. We examined the functional state of the HPA axis in a rat model of co-morbidity between temporal lobe epilepsy and depression. Epilepsy was accompanied by the interictal elevation of plasma corticosterone, and by the positively combined dexamethasone/corticotropin releasing hormone test. The extent of the HPA hyperactivity was independent of recurrent seizures, but positively correlated with the severity of depressive behavior. We suggest that the observed hyperactivity of the HPA axis may underlie co-morbidity between epilepsy and depression. Topics: Animals; Behavior, Animal; Corticosterone; Depression; Disease Models, Animal; Electrodes, Implanted; Epilepsy, Temporal Lobe; Hypothalamo-Hypophyseal System; Lithium Chloride; Male; Microelectrodes; Pilocarpine; Pituitary-Adrenal System; Psychiatric Status Rating Scales; Radioimmunoassay; Random Allocation; Rats; Rats, Wistar; Seizures; Stress, Psychological | 2009 |
EEG stages predict treatment response in experimental status epilepticus.
Progression of severity in experimental status epilepticus (SE), defined as refractoriness to first- and second-line abortive agents, may be related to a five-stage progression of electroencephalography (EEG) patterns. This was tested in the lithium-pilocarpine rat SE model. Abortive treatment with diazepam and phenobarbital was given at EEG stages I, III, and V. In stage I, the combination therapy resulted in 100% SE termination. However, stage III corresponded to high treatment resistance (0% abortion) and stage V to an intermediate response (63%). Comparisons of time-to-treatment durations showed overlap between stage I and stage III, despite having markedly different response rates to abortive medications. Therefore, EEG patterns reflect the dynamic pathophysiology of SE and can be used as reliable and specific markers to distinguish treatment-responsive from treatment-refractory SE more accurately than time alone. Topics: Analysis of Variance; Animals; Anticonvulsants; Diazepam; Disease Models, Animal; Disease Progression; Electroencephalography; Lithium Chloride; Male; Phenobarbital; Pilocarpine; Predictive Value of Tests; Rats; Rats, Sprague-Dawley; Reaction Time; Status Epilepticus; Time Factors | 2009 |
Seizure susceptibility and the brain regional sensitivity to oxidative stress in male and female rats in the lithium-pilocarpine model of temporal lobe epilepsy.
Several studies have shown the existence of sex differences in the sensitivity to various convulsants in animals and to the development of some epilepsy types in humans. The purpose of this study was to investigate whether there are sex differences in seizure susceptibility and sensitivity of different brain regions to oxidative stress in rats with status epilepticus (SE) induced by lithium-pilocarpine administration, that provides a common experimental model of temporal lobe epilepsy (TLE) in humans. Latencies to isolated full limbic seizures or SE onset as well as the number of the animals presenting full limbic seizures, SE or full limbic seizures that progressed to SE were recorded for 2 h after pilocarpine administration. Number of animals which survived 24 h after SE onset was also monitored. Levels of lipid peroxidation as well as the superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities in the piriform and entorhinal cortices, temporal neocortex, thalamus, and hippocampus in rats of both sexes, at 24 h after SE onset were determined. Results of our study showed that males developed full limbic seizures and SE more rapidly and in greater number than females. Levels of lipid peroxidation in all brain regions examined, the SOD activities in the piriform and entorhinal cortices, and temporal neocortex as well as the GSH-Px activities in the piriform and entorhinal cortices, and thalamus were significantly higher in rats with SE in comparison to the values of mentioned biochemical parameters in rats of the control groups. Lipid peroxidation level in the temporal neocortex as well as the GSH-Px activity in the hippocampus in male rats were significantly higher in comparison to the values registered in females. With the exception of the thalamus, where SOD activity in male rats with SE was significantly higher in relation to the respective control group and also to females with SE, sex differences in the response of other brain regions investigated to oxidative stress were not obtained, at 24 h after SE. Topics: Animals; Brain; Disease Models, Animal; Disease Susceptibility; Epilepsy, Temporal Lobe; Female; Glutathione Peroxidase; Lipid Peroxidation; Lithium Chloride; Male; Oxidative Stress; Pilocarpine; Rats; Rats, Wistar; Sex Characteristics; Superoxide Dismutase; Thiobarbituric Acid Reactive Substances | 2009 |
Murine Glut-1 transporter haploinsufficiency: postnatal deceleration of brain weight and reactive astrocytosis.
Glucose transporter type 1 (Glut-1) facilitates glucose flux across the blood-brain-barrier. In humans, Glut-1 deficiency causes acquired microcephaly, seizures and ataxia, which are recapitulated in our Glut-1 haploinsufficient mouse model. Postnatal brain weight deceleration and development of reactive astrogliosis were significant by P21 in Glut-1(+/-) mice. The brain weight differences remained constant after P21 whereas the reactive astrocytosis continued to increase and peaked at P90. Brain immunoblots showed increased phospho-mTOR and decreased phospho-GSK3-beta by P14. After fasting, the mature Glut-1(+/-) females showed a trend towards elevated phospho-GSK3-beta, a possible neuroprotective response. Lithium chloride treatment of human skin fibroblasts from control and Glut-1 DS patients produced a 45% increase in glucose uptake. Brain imaging of mature Glut-1(+/-) mice revealed a significantly decreased hippocampal volume. These subtle immunochemical changes reflect chronic nutrient deficiency during brain development and represent the experimental correlates to the human neurological phenotype associated with Glut-1 DS. Topics: Age Factors; Animals; Animals, Newborn; Apoptosis; Astrocytes; Body Weight; Brain; Carbohydrate Metabolism, Inborn Errors; Carrier Proteins; Cell Proliferation; Cell Size; Cells, Cultured; Dendrites; Disease Models, Animal; Female; Fibroblasts; Gene Expression Regulation, Developmental; Glial Fibrillary Acidic Protein; Gliosis; Glucose Transporter Type 1; Humans; Hypoglycemia; In Situ Nick-End Labeling; Lithium Chloride; Magnetic Resonance Imaging; Male; Mice; Mice, Knockout; Neurons; Organ Size; Phosphotransferases (Alcohol Group Acceptor); Signal Transduction; Skin; TOR Serine-Threonine Kinases | 2009 |
Selective GSK-3beta inhibitors attenuate the cisplatin-induced cytotoxicity of auditory cells.
Glycogen synthase kinase-3 (GSK-3) plays an important role in the regulation of apoptosis. However, the role of GSK-3 in the auditory system remains unknown. Here we examined whether the GSK-3-specific inhibitors, SB 216763 and LiCl, could protect against cisplatin-induced cytotoxicity of auditory cells. GSK-3 was activated by cisplatin treatment of HEI-OC1 cells. SB 216763 or LiCl treatments inhibited cisplatin-induced apoptosis in a dose-dependent manner and activated caspase-9, -8 and -3. In rat primary explants of the organ of Corti, SB 216763 or LiCl treatments completely abrogated the cisplatin-induced destruction of outer hair cell arrays. Administration of SB 216763 or LiCl inhibited cochlear destruction and the production of tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta) and IL-6 in cisplatin-injected mice. Furthermore, administration of SB 216763 or LiCl reduced the thresholds of the auditory brainstem response (ABR) in cisplatin-injected mice. Collectively, these results suggest that cisplatin-induced ototoxicity might be associated with modulation of GSK-3 activation. Topics: Acoustic Stimulation; Animals; Antineoplastic Agents; Apoptosis; Caspases; Cell Line; Cisplatin; Disease Models, Animal; Dose-Response Relationship, Drug; Enzyme Activation; Evoked Potentials, Auditory, Brain Stem; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Hair Cells, Auditory; Hearing Loss; Indoles; Injections, Intraperitoneal; Interleukin-1beta; Interleukin-6; Lithium Chloride; Maleimides; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Organ Culture Techniques; Organ of Corti; Phosphorylation; Protein Kinase Inhibitors; Rats; Rats, Sprague-Dawley; Time Factors; Tumor Necrosis Factor-alpha | 2009 |
Calcium/calmodulin-dependent protein kinase type IV is a target gene of the Wnt/beta-catenin signaling pathway.
Calcium/calmodulin-dependent protein kinase IV (CaMKIV) plays a key role in the regulation of calcium-dependent gene expression. The expression of CaMKIV and the activation of CREB regulated genes are involved in memory and neuronal survival. We report here that: (a) a bioinformatic analysis of 15,476 promoters of the human genome predicted several Wnt target genes, being CaMKIV a very interesting candidate; (b) CaMKIV promoter contains TCF/LEF transcription motifs similar to those present in Wnt target genes; (c) biochemical studies indicate that lithium and the canonical ligand Wnt-3a induce CaMKIV mRNA and protein expression levels in rat hippocampal neurons as well as CaMKIV promoter activity; (d) treatment of hippocampal neurons with Wnt-3a increases the binding of beta-catenin to the CaMKIV promoter: (e) In vivo activation of the Wnt signaling improve spatial memory impairment and restores the expression of CaMKIV in a mice double transgenic model for Alzheimer's disease which shows decreased levels of the kinase. We conclude that CaMKIV is regulated by the Wnt signaling pathway and that its expression could play a role in the neuroprotective function of the Wnt signaling against the Alzheimer's amyloid peptide. Topics: Alzheimer Disease; Animals; Behavior, Animal; beta Catenin; Calcium-Calmodulin-Dependent Protein Kinase Type 4; Cell Line; Computational Biology; Disease Models, Animal; Enhancer Elements, Genetic; Gene Expression; Hippocampus; Humans; Lithium Chloride; Mice; Mice, Inbred Strains; Mice, Transgenic; Neurons; Neuropsychological Tests; Promoter Regions, Genetic; Protein Binding; Rats; Rats, Inbred Strains; Signal Transduction; TCF Transcription Factors; Transfection; Wnt Proteins; Wnt3 Protein; Wnt3A Protein | 2009 |
Status epilepticus induces cardiac myofilament damage and increased susceptibility to arrhythmias in rats.
Status epilepticus (SE) is a seizure or series of seizures that persist for >30 min and often results in mortality. Death rarely occurs during or immediately following seizure activity, but usually within 30 days. Although ventricular arrhythmias have been implicated in SE-related mortality, the effects of this prolonged seizure activity on the cardiac function and susceptibility to arrhythmias have not been directly investigated. We evaluated myocardial damage, alterations in cardiac electrical activity, and susceptibility to experimentally induced arrhythmias produced by SE in rats. SE resulted in seizure-related increases in blood pressure, heart rate, and the first derivative of pressure, as well as modest, diffuse myocyte damage assessed by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling staining. Ten to twelve days following seizures, electrocardiographic recordings showed arrhythmogenic alterations in cardiac electrical activity, denoted by prolonged QT interval corrected for heart rate and QT dispersion. Finally, SE increased susceptibility to experimentally induced (intravenous aconitine) cardiac arrhythmias. These data suggest that SE produces tachycardic ischemia following the activation of the sympathetic nervous system, resulting in cardiac myofilament damage, arrhythmogenic alterations in cardiac electrical activity, and increased susceptibility to ventricular arrhythmias. Topics: Aconitine; Actin Cytoskeleton; Action Potentials; Animals; Arrhythmias, Cardiac; Biomarkers; Blood Pressure; Disease Models, Animal; Disease Susceptibility; Electrocardiography; Heart Rate; In Situ Nick-End Labeling; Lithium Chloride; Male; Myocardium; Pilocarpine; Rats; Rats, Sprague-Dawley; Status Epilepticus; Sympathetic Nervous System; Time Factors; Troponin I | 2009 |
Ischemia and status epilepitcus result in enhanced phosphorylation of calcium and calmodulin-stimulated protein kinase II on threonine 253.
Ca2+-stimulated protein kinase II (CaMKII) is critically involved in the regulation of synaptic function and is implicated in the neuropathology associated with ischemia and status epilepticus (SE). The activity and localization of CaMKII is regulated by multi-site phosphorylation. In the present study we investigated the effects of global ischemia followed by reperfusion and of SE on the phosphorylation of CaMKII on T253 in rat forebrains and compared this to the phosphorylation of T286. Both ischemia and SE resulted in marked increases in the phosphorylation of T253, and this was particularly marked in the postsynaptic density (PSD). Phosphorylation of T286 decreased rapidly towards basal levels following ischemia whereas phosphorylation of T253 remained elevated for between 1 and 6 h before decreasing to control values. Following SE, phosphorylation of T253 remained elevated for between 1 and 3 h before decreasing to control levels. In contrast, phosphorylation of T286 remained elevated for at least 24 h following the termination of SE. Total CaMKII associated with PSDs transiently increased 10 min following ischemia, but only several hours following SE. The results demonstrate that phoshorylation of CaMKII on T253 is enhanced following both ischemia/reperfusion and SE and indicate that the phosphorylation of T253 and T286 are differentially regulated. Topics: Animals; Calcium; Calcium-Calmodulin-Dependent Protein Kinase Type 2; Disease Models, Animal; Ischemia; Lithium Chloride; Male; Phosphorylation; Pilocarpine; Prosencephalon; Rats; Rats, Wistar; Status Epilepticus; Synaptosomes; Threonine | 2008 |
Decreased lithium disposition to cerebrospinal fluid in rats with glycerol-induced acute renal failure.
The lithium disposition to cerebrospinal fluid (CSF) was evaluated in rats with acute renal failure (ARF) to examine whether electrolyte homeostasis of the CSF is perturbed by kidney dysfunction. In addition, the effects of renal failure on choroid plexial expressions of the Na+-K+-2Cl- co-transporter (NKCC1) and Na+/H+ exchanger (NHE1) were also studied.. After lithium was intravenously administered at a dose of 4 mmol/kg, its concentration profile in plasma was evaluated by collecting plasma specimens, while that in CSF was monitored with a microdialysis probe in the lateral ventricles. NKCC1 and NHE1 expressions were measured via the Western immunoblot method using membrane specimens prepared from the choroid plexus in normal and ARF rats.. The lithium concentration in CSF of ARF rats was 30% lower than that of normal rats, while their plasma lithium profiles were almost the same, indicating that the lithium disposition to CSF was decreased in ARF rats. It was revealed that the choroid plexial expression of NKCC1 was increased by 40% in ARF rats, but that of NHE1 was unchanged.. ARF decreases the lithium disposition to CSF, possibly by promoting lithium efflux from CSF due to increased NKCC1 expression in the choroid plexus. Topics: Acute Kidney Injury; Animals; Choroid Plexus; Disease Models, Animal; Glycerol; Injections, Intravenous; Lithium Chloride; Male; Microdialysis; Rats; Rats, Wistar; Sodium-Hydrogen Exchanger 1; Sodium-Hydrogen Exchangers; Sodium-Potassium-Chloride Symporters; Solute Carrier Family 12, Member 2; Water-Electrolyte Balance | 2008 |
Anticonvulsant effect of BmK IT2, a sodium channel-specific neurotoxin, in rat models of epilepsy.
The sodium channel is a primary target for treating central nervous system disorders such as epilepsy. In this study the anticonvulsant effect of BmK IT2, a sodium channel-specific neurotoxin, was evaluated in different animal models of epilepsy.. Experiments were performed on freely moving rats made epileptic by administration of either pentylenetetrazole (PTZ) or pilocarpine. BmK IT2 (0.05-0.5 microg in 2 microl) was microinjected into the CA1 area and its effects on PTZ-induced widespread, seizure-like behaviour and cortex epileptiform EEG, as well as on pilocarpine-induced seizure-like behaviour and c-Fos expression were studied.. Intrahippocampal application of BmK IT2 dose-dependently inhibited PTZ-induced seizure-like behaviour, and reduced the numbers and duration of the high amplitude and frequency discharges (HAFDs) of the epileptiform EEG component induced by PTZ. Similarly, in the pilocarpine-induced status epilepticus (SE) model, BmK IT2 significantly prolonged the latency to onset of the SE, reduced the severity of SE and suppressed hippocampal c-Fos expression during SE.. BmK IT2 showed anticonvulsant activity as it inhibited the widespread seizures induced by PTZ and pilocarpine-induced SE in rats. This activity might be due to the modulation of sodium channels in the hippocampus. Hence, BmK IT2 could be used as a novel tool to explore the molecular and pathological mechanisms of epilepsy with regard to the involvement of sodium channels. Topics: Action Potentials; Animals; Anticonvulsants; Behavior, Animal; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Administration Routes; Electroencephalography; Hippocampus; Lithium Chloride; Male; Pentylenetetrazole; Pilocarpine; Proto-Oncogene Proteins c-fos; Rats; Rats, Sprague-Dawley; Scorpion Venoms; Seizures; Sodium Channels | 2008 |
Combined lithium and valproate treatment delays disease onset, reduces neurological deficits and prolongs survival in an amyotrophic lateral sclerosis mouse model.
Lithium and valproic acid (VPA) are two primary drugs used to treat bipolar disorder, and have been shown to have neuroprotective properties in vivo and in vitro. A recent study demonstrated that combined treatment with lithium and VPA elicits synergistic neuroprotective effects against glutamate excitotoxicity in cultured brain neurons, and the synergy involves potentiated inhibition of glycogen synthase kinase-3 (GSK-3) activity through enhanced GSK-3 serine phosphorylation [Leng Y, Liang MH, Ren M, Marinova Z, Leeds P, Chuang DM (2008) Synergistic neuroprotective effects of lithium and valproic acid or other histone deacetylase inhibitors in neurons: roles of glycogen synthase kinase-3 inhibition. J Neurosci 28:2576-2588]. We therefore investigated the effects of lithium and VPA cotreatment on the disease symptom onset, survival time and neurological deficits in cooper zinc superoxide dismutase (SOD1) G93A mutant mice, a commonly used mouse model of amyotrophic lateral sclerosis (ALS). The G93A ALS mice received twice daily i.p. injections with LiCl (60 mg/kg), VPA (300 mg/kg) or lithium plus VPA, starting from the 30(th) day after birth and continuing until death. We found that combined treatment with lithium and VPA produced a greater and more consistent effect in delaying the onset of disease symptoms, prolonging the lifespan and decreasing the neurological deficit scores, compared with the results of monotreatment with lithium or VPA. Moreover, lithium in conjunction with VPA was more effective than lithium or VPA alone in enhancing the immunostaining of phospho-GSK-3beta(Ser9) in brain and lumbar spinal cord sections. To our knowledge, this is the first demonstration of enhanced neuroprotection by a combinatorial approach using mood stabilizers in a mouse ALS model. Our results suggest that clinical trials using lithium and VPA in combination for ALS patients are a rational strategy. Topics: Adjuvants, Immunologic; Age Factors; Amyotrophic Lateral Sclerosis; Animals; Anticonvulsants; Behavior, Animal; Disease Models, Animal; Drug Therapy, Combination; Glycogen Synthase Kinase 3; Hindlimb Suspension; Humans; Lithium Chloride; Mice; Mice, Transgenic; Motor Activity; Muscle Strength; Mutation; Nervous System Diseases; Psychomotor Performance; Reflex; Rotarod Performance Test; Superoxide Dismutase; Survival Analysis; Valproic Acid | 2008 |
Novel treatment for lithium-induced nephrogenic diabetes insipidus rat model using the Sendai-virus vector carrying aquaporin 2 gene.
Congenital nephrogenic diabetes insipidus (NDI) is a chronic disorder involving polyuria and polydipsia that results from unresponsiveness of the renal collecting ducts to the antidiuretic hormone vasopressin. Either of the genetic defects in vasopressin V2 receptor or the water channel aquaporin 2 (AQP2) cause the disease, which interfere the water reabsorption at the epithelium of the collecting duct. An unconscious state including a perioperative situation can be life threatening because of the difficulty to regulate their water balance. The Sendai virus (SeV) vector system deleting fusion protein (F) gene (SeV/DeltaF) is considered most suitable because of the short replication cycle and nontransmissible character. An animal model for NDI with reduced AQP2 by lithium chloride was used to develop the therapy. When the SeV/DeltaF vector carrying a human AQP2 gene (AQP2-SeV/DeltaF) was administered retrogradely via ureter to renal pelvis, AQP2 was expressed in the renal collecting duct to reduce urine output and water intake by up to 40%. In combination with the retorograde administration to pelvis, this system could be the cornerstone for the applicable therapies on not only NDI patients but also other diseases associate with the medullary collecting duct. Topics: Amino Acid Sequence; Animals; Aquaporin 2; Cloning, Molecular; Diabetes Insipidus, Nephrogenic; Disease Models, Animal; Genetic Therapy; Genetic Vectors; Humans; Lithium Chloride; Male; Models, Biological; Molecular Sequence Data; Oligopeptides; Oocytes; Peptides; Rats; Rats, Sprague-Dawley; Sendai virus; Transgenes; Tumor Cells, Cultured; Xenopus laevis | 2008 |
Preconditioning with acute and chronic lithium administration reduces ischemia/reperfusion injury mediated by cyclooxygenase not nitric oxide synthase pathway in isolated rat heart.
Lithium is widely used for the management of neuropsychiatric symptoms in bipolar disorders. A variety of hypotheses have been invoked to explain the mechanism of action of lithium. To determine if lithium exerts direct cardiac protection, in the present study perfused rat heart model was used. The mechanism of lithium-mediated cardioprotection was explored by combined use of lithium and nitro-L-arginine methyl ester (L-NAME, a non-selective nitric oxide synthase inhibitor) or indomethacin (a non-selective cyclooxygenase pathway inhibitor). Rat isolated hearts were used for Langendorff perfusion. Hearts were either non-preconditioned or preconditioned with acute lithium (3 mM) or chronic lithium (600 mg/l in tap water for 4 weeks, 0.265 +/- 0.023 mM in serum) before 30 min global ischemia followed by 90 min reperfusion. Within each of these protocols, hearts were divided into two groups; one group was exposed to L-NAME (0.1 mM) and another group was exposed to indomethacin (10 microM). Infarct size was measured by the triphenyltetrazolium chloride method. Left ventricular function was assessed by left ventricular developed pressure (LVDP), heart rate and coronary flow (CF). In our experiment acute and/or chronic administration of lithium before prolonged ischemia offered significant myoprotective effects in terms of infarct size reduction and improved cardiac function against ischemia/reperfusion injury. The effects of lithium pretreatment were prevented by the administration of indomethacin but not L-NAME. In conclusion, our results demonstrate that preconditioning with acute and/or chronic lithium administration improves recovery of the ventricular function and reduces infarct size via cyclooxygenase (COX) pathway in isolated rat heart. Topics: Animals; Cardiotonic Agents; Cyclooxygenase Inhibitors; Disease Models, Animal; Dose-Response Relationship, Drug; In Vitro Techniques; Indomethacin; Lithium Chloride; Male; Myocardial Contraction; Myocardial Infarction; Myocardial Reperfusion Injury; Myocardium; NG-Nitroarginine Methyl Ester; Nitric Oxide Synthase; Perfusion; Prostaglandin-Endoperoxide Synthases; Rats; Rats, Sprague-Dawley; Recovery of Function; Ventricular Function, Left; Ventricular Pressure | 2008 |
Altered expression of voltage-gated potassium channel 4.2 and voltage-gated potassium channel 4-interacting protein, and changes in intracellular calcium levels following lithium-pilocarpine-induced status epilepticus.
The A-type voltage-gated potassium channels (Kv4) have been proved to play a major role as modulators of somatodendritic excitability. Recent studies indicate that neuronal hyperactivity in epilepsy is associated with changes in Kv4. However, the precise regulation of Kv4 in the development of epilepsy and its underlying mechanism remain unclear. In this study, we investigated whether the expression of the Kv4.2 channel and of its major modulator, voltage-dependent potassium channel-interacting protein (KChIP1), is altered following lithium-pilocarpine induced status epilepticus (SE) and the chronic-epilepsy phase in the rat model. We found that Kv4.2 and KChIP1 expression was transiently up-regulated following SE, whereas it was down-regulated during the chronic phase: this was most prominent in the CA1 and CA3 regions. The time-course analysis of the protein expression level showed that the peak Kv4.2 up-regulation was between 6 and 24 h after SE, whereas KChIP1 expression was increased earlier and for a shorter period. The temporospatial changes in Kv4.2 were very similar to those of its major modulator KChIP1. We compared the difference in 4-aminopyridine (4-AP)-induced intracellular calcium ([Ca(2+)]i) elevation between model and control brain slices. The results showed that the [Ca(2+)]i elevation induced by the Kv4 channel blocker 4-AP was aggravated and prolonged in the model slice after SE. The functional relevance of these changes in Ca(2+) homeostasis and Kv4.2 and KChIP1 expression may be associated with intrinsic neuronal excitability regulation and epileptogenesis. Topics: 4-Aminopyridine; Animals; Calcium; Disease Models, Animal; Extracellular Fluid; Female; Gene Expression Regulation; Hippocampus; In Vitro Techniques; Kv Channel-Interacting Proteins; Lithium Chloride; Pilocarpine; Potassium Channel Blockers; Rats; Rats, Sprague-Dawley; Shal Potassium Channels; Status Epilepticus; Time Factors | 2008 |
Omega-3 fatty acid deficiency augments amphetamine-induced behavioral sensitization in adult mice: prevention by chronic lithium treatment.
Emerging data suggests that omega-3 fatty acid deficiency may be a risk factor for bipolar disorder. In the present study, we determined the effects of chronic dietary-induced omega-3 fatty acid deficiency and/or concomitant chronic lithium chloride (LiCl) treatment on amphetamine (AMPH)-induced behavioral sensitization, a phenomenon that may recruit neuroplastic mechanisms relevant to the pathophysiology of bipolar disorder.. Adult male C57BL/6J mice were randomly assigned to one four diets: Control (alpha-linolenic-fortified), Control+LiCl (0.255%), alpha-linolenic-Deficient, or Deficient+LiCl (0.255%), and behavioral testing initiated 65 days later. Locomotor activity was determined following 3 intermittent (separated by 7d) injections of amphetamine (AMPH) (1mg/kg). After behavioral testing, red blood cell (RBC) and regional brain (prefrontal cortex, hippocampus, ventral striatum) fatty acid composition was determined by gas chromatography.. Each diet group exhibited comparable locomotor activity following acute AMPH treatment. However, the development of sensitization following repeated AMPH treatment was significantly augmented in Deficient mice relative to controls, and this augmented response was prevented by chronic LiCl treatment. Relative to controls, Deficient mice exhibited deficits in RBC and regional brain docosahexaenoic acid (DHA, 22:6n-3) composition, reciprocal elevations in vaccenic acid (18:1n-7), arachidonic acid (AA, 20:4n-6), and docosapentaenoic acid (DPA, 22:5n-6) compositions, and elevations in AA:DHA, oleic acid:DHA, and DPA:DHA ratios. The fatty acid abnormalities in Deficient mice were not altered by concurrent chronic lithium treatment. Mice fed the Control+LiCl diet exhibited a significant increase in AA composition in RBC and all brain regions, and an elevated AA:DHA ratio in the prefrontal cortex and hippocampus, relative to Controls. Fatty acid composition in RBC and different brain regions were predominantly positively correlated. Within the ventral striatum, DHA composition was inversely correlated, and AA:DHA and oleic acid:DHA ratios positively correlated, with total distance traveled following the final AMPH treatment.. These data indicate that alterations in fatty acid composition resulting from dietary-induced omega-3 fatty acid deficiency augment the development of AMPH-induced behavioral sensitization in a manner that is prevented by chronic lithium treatment. The implications of these findings for understanding the contribution of omega-3 fatty acid deficiency to the pathophysiology and progression of bipolar disorder are discussed. Topics: Amphetamine; Animals; Antimanic Agents; Bipolar Disorder; Central Nervous System Stimulants; Disease Models, Animal; Drug Administration Schedule; Drug Hypersensitivity; Fatty Acid Desaturases; Hippocampus; Hypothalamus; Lithium Chloride; Locomotion; Male; Mice; Mice, Inbred C57BL; Random Allocation | 2008 |
The effect of cannabidiol and URB597 on conditioned gaping (a model of nausea) elicited by a lithium-paired context in the rat.
Anticipatory nausea (AN) experienced by chemotherapy patients is resistant to current anti-nausea treatments. In this study, the effect of manipulation of the endocannabinoid (EC) system on a rat model of nausea (conditioned gaping) was determined.. The potential of cannabidiol (CBD) and the fatty acid amide hydrolase (FAAH) inhibitor, URB597 (URB) to reduce conditioned gaping in rats were evaluated.. In each experiment, rats received four conditioning trials in which they were injected with lithium chloride immediately before placement in a distinctive odor-laced context. During testing, in experiment 1, rats were injected with vehicle (VEH), 1, 5 or 10 mg/kg CBD 30 min before placement in the context previously paired with nausea and in experiment 2, rats were injected with VEH, 0.1 or 0.3 mg/kg URB 2 h before placement in the context. Additional groups evaluated the ability of the CB(1) antagonist/inverse agonist, SR141716A, to reverse the suppressive effects of URB. Experiment 3 measured the potential of URB to interfere with the establishment of conditioned gaping.. When administered before testing, CBD (1 and 5, but not 10 mg/kg) and URB (0.3, but not 0.1 mg/kg) suppressed conditioned gaping. The effect of URB was reversed by pre-treatment with the CB(1) antagonist/inverse agonist, SR141716A. When administered before conditioning, URB also interfered with the establishment of conditioned gaping.. Manipulations of the EC system may have therapeutic potential in the treatment of AN. Topics: Amidohydrolases; Animals; Antiemetics; Antineoplastic Agents; Benzamides; Cannabidiol; Carbamates; Conditioning, Classical; Disease Models, Animal; Dose-Response Relationship, Drug; Lithium Chloride; Male; Nausea; Rats; Rats, Long-Evans; Rats, Sprague-Dawley; Vomiting, Anticipatory | 2008 |
TrkB agonists ameliorate obesity and associated metabolic conditions in mice.
Mutations in the tyrosine kinase receptor trkB or in one of its natural ligands, brain-derived neurotrophic factor (BDNF), lead to severe hyperphagia and obesity in rodents and/or humans. Here, we show that peripheral administration of neurotrophin-4 (NT4), the second natural ligand for trkB, suppresses appetite and body weight in a dose-dependent manner in several murine models of obesity. NT4 treatment increased lipolysis, reduced body fat content and leptin, and elicited long-lasting amelioration of hypertriglyceridemia and hyperglycemia. After treatment termination, body weight gradually recovered to control levels in obese mice with functional leptin receptor. A single intrahypothalamic application of minute amounts of NT4 or an agonist trkB antibody also reduced food intake and body weight in mice. Taken together with the genetic evidence, our findings support the concept that trkB signaling, which originates in the hypothalamus, directly modulates appetite, metabolism, and taste preference downstream of the leptin and melanocortin 4 receptor. The trkB agonists mediate anorexic and weight-reducing effects independent of stress induction, visceral discomfort, or pain sensitization and thus emerge as a potential therapeutic for metabolic disorders. Topics: Animals; Body Weight; Disease Models, Animal; Eating; Energy Metabolism; Glucose; Homeostasis; Leptin; Lithium Chloride; Male; Melanocortins; Mice; Mice, Inbred C57BL; Mice, Obese; Nerve Growth Factors; Obesity; Rats; Rats, Sprague-Dawley; Receptor, trkB; Receptors, Leptin; Taste; Triglycerides | 2008 |
Effect of the new antiepileptic drug retigabine in a rodent model of mania.
Bipolar spectrum disorders are severe chronic mood disorders that are characterized by episodes of mania or hypomania and depression. Because patients with manic symptoms often experience clinical benefit from treatment with anticonvulsant drugs, it was hypothesized that retigabine, a novel compound with anticonvulsant efficacy, may also possess antimanic activity. The amphetamine (AMPH)+chlordiazepoxide (CDP)-induced hyperactivity model has been proposed as a suitable model for studying antimanic-like activity of novel compounds in mice and rats. The aims of the present study in rats were therefore (1) to confirm previous findings with lithium and lamotrigine, and (2) to evaluate the effect of the novel compound retigabine on AMPH+CDP-induced hyperactivity in rats. In all experiments, co-administration of AMPH and CDP induced a significant increase (191-295%) in locomotor activity. Lithium chloride (0.9 mg/kg) and lamotrigine (20 mg/kg), which are known to effectively stabilize mood in humans, both significantly decreased AMPH+CDP-induced locomotor activity without affecting basal locomotor activity. The results furthermore indicate that retigabine, like lithium and lamotrigine, significantly and dose-dependently attenuates the induced hyperactivity at a lowest effective dose of 1.0 mg/kg, whereas basal locomotor activity is reduced only at doses 4.0 mg/kg. In conclusion, retigabine was found to have an antimanic-like effect in the AMPH+CDP-induced hyperactivity model, suggesting a potential role for retigabine in the treatment of mania and possibly in the management of bipolar disorder. Topics: Amphetamine; Animals; Anticonvulsants; Behavior, Animal; Bipolar Disorder; Carbamates; Chlordiazepoxide; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Interactions; Lamotrigine; Lithium Chloride; Male; Motor Activity; Phenylenediamines; Rats; Rats, Wistar; Triazines | 2008 |
Functional MRI of delayed chronic lithium treatment in rat focal cerebral ischemia.
The use of lithium as a neuroprotective agent has been demonstrated using various models in which improvements in infarct size, DNA damage, and neurological function were reported. We further investigated neurohemodynamic aspects of the treatment-associated recovery by assessing the therapeutic efficacy of delayed chronic lithium treatment using functional MRI.. Ipsilesional functional MRI activations in the somatosensory cortex, acquired 2 weeks after the 90-minute transient middle cerebral artery occlusion, were compared between lithium- and saline-treated rats. Specifically, MRI signal changes based on blood oxygenation level dependence and functional cerebral blood volume responses were examined using electrical stimulation of forelimbs. Additional immunohistochemical assays were performed.. The ratio of ipsilesional to contralesional blood oxygenation level dependence response magnitudes significantly improved with lithium treatments. In contrast, the increase of the functional cerebral blood volume response magnitude ratio was not statistically significant. Nonetheless, the lithium treatment induced significant enhancements of total functional MRI activation (defined as a product of activation volume and response magnitude) for both blood oxygenation level dependence and functional cerebral blood volume methods. Increased cerebral blood volume in periinfarct tissues suggests a possible stroke-induced vascular transformation in both saline- and lithium-treated rats; however, other MRI-derived vascular parameters (vascular size index and microvascular volume) and immunohistochemical staining (CD31, glia fibrillary-associated protein, and matrix metalloproteinase-9) may imply that the neoformation of vasculature was differently affected by the lithium treatment.. The delayed chronic lithium treatment enhanced the blood oxygenation level dependence functional MRI response magnitude in the absence of neurological improvement and influenced vascular formation in poststroke animal models. Topics: Animals; Brain Ischemia; Cerebrovascular Circulation; Disease Models, Animal; Infarction, Middle Cerebral Artery; Lithium Chloride; Magnetic Resonance Imaging; Male; Models, Neurological; Neuroprotective Agents; Oxygen; Rats; Rats, Sprague-Dawley | 2008 |
Lithium blocks stress-induced changes in depressive-like behavior and hippocampal cell fate: the role of glycogen-synthase-kinase-3beta.
Mood disorders are the most common psychiatric disorders. Although the mechanisms implicated in the genesis of mood disorders are still unclear, stress is known to predispose to depression, and recently, studies have related hippocampal neurogenesis and apoptosis to depression. In the present study we first examined the balance between cell birth-death in the hippocampus and subventricular zone (SVZ) of pre-pubertal and adult rats subjected to chronic-mild-stress (CMS). CMS led to increased corticosterone secretion and induced depressive-like symptoms (assessed in the forced-swimming test); these endocrine and behavioral effects were paralleled by decreased hippocampal, but not SVZ, cell proliferation/differentiation and by increased apoptotic rate. In order to determine if lithium, a known mood stabilizer with antidepressant properties, could prevent the stress-induced events, we analyzed the same parameters in a group of rats treated with lithium during the stress exposure period (CMS+Li) and observed that the hormonal, behavioral and cell turnover effects of CMS were abrogated in these animals. Subsequently, to search for possible pathways through which CMS and lithium influence behavior, cell fate and synaptic plasticity, we analyzed the expression of glycogen-synthase-kinase-3beta (GSK-3beta), as well as some of its downstream targets (B-cell-CLL/lymphoma2-associated athanonege (BAG-1) and synapsin-I). CMS increased GSK-3beta and decreased synapsin-I and BAG-1 expression in the hippocampus. Interestingly, co-administration of lithium precluded the CMS-induced effects in GSK-3beta, synapsin-I and BAG-1 expression. Our observation that specific inhibition of this kinase with AR-A014418 blocked the effects of CMS in depressive-like behavior and in BAG-1 and synapsin-I expression confirmed the involvement of the GSK-3beta pathway in stress-induced effects. In summary, these results reveal that lithium, by regulating the activity of GSK-3beta, prevents the deleterious effects of stress on behavior and cellular functions. Topics: Adrenal Glands; Animals; Antimanic Agents; Behavior, Animal; Body Weight; Cell Proliferation; Cell Survival; Corticosterone; Depressive Disorder; Disease Models, Animal; DNA-Binding Proteins; Enzyme Inhibitors; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Hippocampus; Lithium Chloride; Male; Neuronal Plasticity; Neurons; Rats; Rats, Wistar; Stem Cells; Stress, Psychological; Synapsins; Synaptic Transmission; Transcription Factors; Up-Regulation | 2008 |
Effect of pressure overload on cardioprotection of mitochondrial KATP channels and GSK-3beta: interaction with the MPT pore.
The mitochondrial permeability transition (MPT) pore may serve as the end-effector of cardioprotective mechanisms, namely the mitochondrial K(ATP) channels and glycogen synthase kinase-3beta (GSK-3beta). We recently showed that augmented MPT pore induction contributes to pressure overload-induced exacerbation of infarct size. This study tests the hypotheses that (i) elevation in perfusion pressure attenuates cardioprotection associated with activation of mitochondrial KATP channels or inhibition of GSK-3beta and (ii) perfusion pressure modulates the regulation of the MPT pore by mitochondrial KATP channels and/or GSK-3beta.. Langendorff-perfused hearts were subjected to a regional ischemia-reperfusion insult at a perfusion pressure of either 80 or 160 cm H2O. The perfusion medium contained no drug, diazoxide (80 micromol/l; mitochondrial KATP channel opener), lithium chloride (LiCl, 1 mmol/l; nonselective inhibitor of GSK-3beta), SB-216763 (3 micromol/l; selective inhibitor of GSK-3beta), cyclosporine A (0.2 micromol/l; inhibitor of MPT pore induction), glibenclamide (50 micromol/l; inhibitor of KATP channels), and the combination of cyclosporine A and glibenclamide or the combination of glibenclamide and LiCl.. The increase in perfusion pressure in the absence of a drug caused larger infarcts, an effect associated with poorer recovery of function following ischemia reperfusion. Treatment with either diazoxide or cyclosporine A reduced infarct size at both perfusion pressures but in contrast to diazoxide, cyclosporine A was more protective at the higher pressure. On the other hand, LiCl and SB-216763 reduced infarct size at both pressures, with the effect more marked at the higher perfusion pressure. Glibenclamide did not affect infarct size but eliminated the cardioprotective effect of cyclosporine A while having no effect on LiCl-induced cardioprotection.. Perfusion pressure primarily affects GSK-3beta-mediated regulation of MPT pore formation in the ischemic reperfused heart. Topics: Animals; Cardiotonic Agents; Cyclosporine; Diazoxide; Disease Models, Animal; Glyburide; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Hypertension; In Vitro Techniques; Indoles; Lithium Chloride; Male; Maleimides; Mitochondria, Heart; Mitochondrial Membrane Transport Proteins; Mitochondrial Permeability Transition Pore; Myocardial Infarction; Myocardial Reperfusion Injury; Myocardium; Perfusion; Potassium Channel Blockers; Potassium Channels; Protein Kinase Inhibitors; Rats; Rats, Sprague-Dawley; Ventricular Function, Left; Ventricular Pressure | 2008 |
Effect of TTX suppression of hippocampal activity following status epilepticus.
Status epilepticus (SE) is a severe neurological condition that can result in brain damage. In animals, SE is associated with cell loss and aberrant synaptogenesis. These pathological processes appear to be activity-dependent and may continue after the SE has ended. We postulated that suppression of electrical activity following SE at the site of the epileptic focus will reduce seizure-induced damage. To achieve this goal, tetrodotoxin (TTX) was used to suppress electrical activity in the hippocampi bilaterally following SE. Adult rats experienced lithium-pilocarpine-induced SE for 2h while controls underwent sham-SE with saline injections. Starting 12h after the SE or sham-SE rats received either continuous TTX (1 microM) or saline infusions through cannulas implanted in the bilateral hippocampi for 5h daily for 4 days. TTX resulted in significant EEG suppression and reduction in spikes and sharp waves. Rats were sacrificed 2 weeks after SE and the brains examined for cell loss and sprouting. Rats receiving TTX following SE had significantly more cell loss as well as a trend toward more mossy fiber sprouting than saline-treated rats following SE. TTX injection in sham-SE rats caused no cell loss or mossy fiber sprouting. These results suggest that suppression of electrical activity following SE is detrimental. Topics: Analysis of Variance; Anesthetics, Local; Animals; Disease Models, Animal; Electroencephalography; Hippocampus; Lithium Chloride; Male; Pilocarpine; Rats; Rats, Sprague-Dawley; Staining and Labeling; Status Epilepticus; Tetrodotoxin | 2008 |
Lithium effectively complements vasopressin V2 receptor antagonist in the treatment of hyponatraemia of SIADH rats.
Although, pharmacological intervention with a selective arginine vasopressin (AVP) V(2) receptor antagonist has been demonstrated to be effective for syndrome of inappropriate secretion of antidiuretic hormone (SIADH), its long-term administration has some therapeutic limitations. Lithium, a drug for bipolar disorders, has been known to cause nephrogenic diabetes insipidus by reducing kidney-specific apical water channel, aquaporin 2 (AQP2) expression in the collecting ducts. However, its pharmacological efficacy for SIADH still remains to be elucidated.. Hyponatraemia was induced in male Sprague-Dawley rats by water loading and subcutaneous infusion of 1-deamino-8-D-arginine vasopressin. For the treatment, lithium chloride (LiCl) was administered singly or in combination with OPC-31260 and/or furosemide for 7 days. Protein expression of AQP2 was examined by western blotting at the end of the observation period.. The LiCl administration elevated serum sodium levels in a dose-dependent manner. The therapeutic effect started 3 days after the initial administration and gradually increased. Western blot analysis at the end of the treatment demonstrated dose-dependent reduction of AQP2 protein expression. Additional administration of LiCl (100 mg/kg/day, the dose demonstrated to maintain serum lithium concentration within therapeutic range) to low dose OPC-31260 maintained well the initial elevation of serum sodium level during the treatment. Western blot analysis after combination therapy demonstrated the absence of re-increase in AQP2 expression noted at the end of OPC-31260 treatment. However, further additive effect could not be obtained even when both LiCl and furosemide were added together to low dose OPC-31260.. Although the single effect of therapeutic dose of lithium was weak, it effectively and safely compensated for the therapeutic limitations of a low dose of AVP V(2) receptor antagonist for SIADH by reducing AQP2 expression. Topics: Animals; Antidiuretic Hormone Receptor Antagonists; Aquaporin 2; Benzazepines; Diabetes Insipidus, Nephrogenic; Disease Models, Animal; Drug Synergism; Furosemide; Hyponatremia; Inappropriate ADH Syndrome; Kidney Tubules, Collecting; Lithium Chloride; Male; Rats; Rats, Sprague-Dawley; Receptors, Vasopressin | 2007 |
Depression and/or potentiation of cortical responses after status epilepticus in immature rats.
Lithium-pilocarpine status epilepticus (SE) resulted in delayed changes of single cortical interhemisperic (transcallosal) responses in immature rats. Low-frequency stimulation inducing depression and/or potentiation was studied to analyze possible dynamic changes in cortical responses. Status was elicited in 12-day-old (SE12) or 25-day-old (SE25) rats. Control siblings received saline instead of pilocarpine. Interhemispheric responses were elicited by stimulation of the sensorimotor region of the cerebral cortex 3, 6, 9, 13, or 26 days after status. A series of 5 biphasic pulses with intensity equal to twofold threshold were used for stimulation. The interval between pulses was 100, 125, 160, 200 or 300 ms, eight responses were always averaged. Peak amplitude of the first positive, first negative and second positive waves was measured and responses to the second, third, fourth and fifth pulse were compared with the first one. Animals after status epilepticus as well as lithium-paraldehyde controls exhibit a frequency depression at nearly all the intervals studied. An outlined increase of responses in SE rats in comparison with the controls three days after SE stayed just below the level of statistical significance. In addition, animals in the SE12 group exhibited potentiation of responses at this interval after SE. With longer intervals after SE, the relation between SE and control animals changed twice resulting in a tendency to lower amplitude of responses in SE than in control rats 26 days after SE. Rats in the SE25 group exhibited higher responses than controls 13 days after status, but this difference was not present at the longest interval after SE. Low-frequency stimulation did not reveal increased cortical excitability as a long-lasting consequence of status epilepticus induced in immature rats. In addition, the outlined differences between SE and control rats changed with the time after SE. Topics: Animals; Cerebral Cortex; Disease Models, Animal; Electric Stimulation; Electroencephalography; Evoked Potentials; Lithium Chloride; Long-Term Potentiation; Long-Term Synaptic Depression; Male; Pilocarpine; Rats; Rats, Wistar; Status Epilepticus; Time Factors | 2007 |
Lithium-methomyl induced seizures in rats: a new model of status epilepticus?
Behavioral, electroencephalographic (EEG) and neuropathological effects of methomyl, a carbamate insecticide reversibly inhibiting acetylcholinesterase activity, were studied in naive or lithium chloride (24 h, 3 mEq/kg, s.c.) pretreated male Wistar rats. In naive animals, methomyl with equal potency produced motor limbic seizures and fatal status epilepticus. Thus, the CD50 values (50% convulsant dose) for these seizure endpoints were almost equal to the LD50 (50% lethal dose) of methomyl (13 mg/kg). Lithium pretreated rats were much more susceptible to convulsant, but not lethal effect of methomyl. CD50 values of methomyl for motor limbic seizures and status epilepticus were reduced by lithium pretreatment to 3.7 mg/kg (a 3.5-fold decrease) and 5.2 mg/kg (a 2.5-fold decrease), respectively. In contrast, lithium pretreatment resulted in only 1.3-fold decrease of LD50 value of methomyl (9.9 mg/kg). Moreover, lithium-methomyl treated animals developed a long-lasting status epilepticus, which was not associated with imminent lethality observed in methomyl-only treated rats. Scopolamine (10 mg/kg) or diazepam (10 mg/kg) protected all lithium-methomyl treated rats from convulsions and lethality. Cortical and hippocampal EEG recordings revealed typical epileptic discharges that were consistent with behavioral seizures observed in lithium-methomyl treated rats. In addition, convulsions induced by lithium-methomyl treatment were associated with widespread neurodegeneration of limbic structures. Our observations indicate that lithium pretreatment results in separation between convulsant and lethal effects of methomyl in rats. As such, seizures induced by lithium-methomyl administration may be an alternative to lithium-pilocarpine model of status epilepticus, which is associated with high lethality. Topics: Animals; Anticonvulsants; Diazepam; Disease Models, Animal; Drug Synergism; Electroencephalography; Lithium Chloride; Male; Methomyl; Rats; Rats, Wistar; Scopolamine; Seizures; Status Epilepticus | 2007 |
Lithium improves the behavioral disorder in rats subjected to transient global cerebral ischemia.
Previous study has indicated that chronic treatment with lithium protects brain against ischemic injury by reducing apoptotic death. To investigate whether lithium improves the behavioral disorder induced by transient global cerebral ischemia, we examined the effects of lithium treatment on the performance of rats in a set of behavioral tests, i.e. beam balance, elevated plus maze (EPM), open field and Morris water maze. Our results showed that lithium attenuated the worse general 'well-being' and the worse performance in beam balance, and hyperactivity in EPM and open field, including increased open arm entries, time spent in the open arms, squares crossed, rearing and grooming over 7 days after 15min ischemia, which were induced by four-vessel occlusion in Sprague-Dawley rats. Moreover, lithium improved the injured spatial learning and memory ability in Morris water maze at post-ischemic days 8 and 9. Histological analysis displayed that it decreased obviously cell death in hippocampal CA1 region. Our study further confirmed the protective role of lithium in the ischemia-reperfusion injury and suggested that lithium might be a helpful therapeutic approach to the treatment of stroke combining with other neuroprotective agents. Topics: Animals; Antipsychotic Agents; Behavior, Animal; Cell Count; Disease Models, Animal; Exploratory Behavior; Hippocampus; Ischemic Attack, Transient; Lithium Chloride; Male; Maze Learning; Mental Disorders; Psychomotor Performance; Rats; Rats, Sprague-Dawley; Survival Rate; Time Factors | 2007 |
Effects of lithium and valproate on hippocampus citrate synthase activity in an animal model of mania.
Some studies suggest that mitochondrial dysfunction may be related to the pathophysiology of bipolar disorder. In this work, we evaluated the activity of citrate synthase in rats, and the effects of the treatment with mood stabilizers (lithium and valproate) on the enzyme activity. In the first experiment (reversal treatment), amphetamine or saline were administered to rats for 14 days, and between day 8 and 14, rats were treated with either lithium, valproate or saline. In the second experiment (prevention treatment), rats were pretreated with lithium, valproate or saline, and between day 8 and 14, rats were administered amphetamine or saline. In reversal and prevention models, amphetamine administration significantly inhibited citrate synthase activity in rat hippocampus. In amphetamine-pretreated animals, valproate administration reversed citrate synthase activity inhibition induced by amphetamine. In the prevention model, pretreatment with lithium prevented amphetamine-induced citrate synthase inhibition. Our results showed that amphetamine inhibited citrate synthase activity and that valproate reversed and lithium prevented the enzyme inhibition. Topics: Amphetamine; Analysis of Variance; Animals; Antimanic Agents; Bipolar Disorder; Citrate (si)-Synthase; Disease Models, Animal; Drug Interactions; Hippocampus; Lithium Chloride; Male; Rats; Rats, Wistar; Valproic Acid | 2007 |
Status epilepticus triggers caspase-3 activation and necrosis in the immature rat brain.
The mode and mechanism of neuronal death induced by status epilepticus (SE) in the immature brain have not been fully characterized. In this study, we analyzed the contribution of neuronal necrosis and caspase-3 activation to CA1 damage following lithium-pilocarpine SE in P14 rat pups. By electron microscopy, many CA1 neurons displayed evidence of early necrosis 6 hours following SE, and the full ultrastructural features of necrosis at 24-72 hours. Caspase-3 was activated in injured (acidophilic) neurons 24 hours following SE, raising the possibility that they died by caspase-dependent "programmed" necrosis. Topics: Animals; Animals, Newborn; Autophagy; Brain; Caspase 3; Cell Death; Disease Models, Animal; Dizocilpine Maleate; Excitatory Amino Acid Antagonists; Female; Lithium Chloride; Male; Microscopy, Electron; Necrosis; Neurons; Pilocarpine; Pyramidal Cells; Rats; Rats, Wistar; Status Epilepticus | 2007 |
[Correlation between hippocampal mossy fiber sprouting and synaptic reorganization and mechanisms of temporal lobe epilepsy].
To explore the effects of the ultrastructural features of sprouted mossy fiber synapses in the mechanism of temporal lobe epilepsy. To explore the correlation between axon guidance molecule-netrin-1 gene expression and mossy fiber synaptic reorganization.. Sixty-one SD rats underwent intraperitoneal injection of lithium chloride and pilocarpine to establish models of status epilepticus characterized with temporal lobe epilepsy. Nineteen rats were used as controls. One, 2, and 4 weeks after the injection, a certain numbers of rat were killed with their brains taken out. The sprouted mossy fiber synaptic terminals were labeled by Timm histochemistry and the ultrastructure of new synapses were observed by electron microscopy. By in situ hybridization, the mRNA expression of netrin-1 gene was observed.. The sprouted mossy fiber synapses in epileptic rats most commonly formed asymmetric synapses with dendritic spines and occasionally with granule cell somata. Seven days after the injection, up-regulation of netrin-1 mRNA expression was seen in the dentate granule cell layers of hippocampus and continued to 4 weeks after the injection. The time course of the increase of netrin-1 mRNA in the dentate granule cell layers was correlated with the time course of mossy fiber sprouting and synaptic reorganization in hippocampus.. The ultrastructural features of sprouted mossy fiber synapses support the viewpoint that the reorganization of synapses prominently involves the formation of recurrent excitatory circuits. The axon guidance molecule- netrin-1 plays an important role in the process of mossy fiber axonal outgrowth and synaptogenesis in the hippocampal dentate gyrus. Topics: Animals; Disease Models, Animal; Epilepsy; Epilepsy, Temporal Lobe; In Situ Hybridization; Lithium Chloride; Male; Microscopy, Electron; Mossy Fibers, Hippocampal; Nerve Growth Factors; Netrin-1; Pilocarpine; Random Allocation; Rats; Rats, Sprague-Dawley; RNA, Messenger; Synapses; Tumor Suppressor Proteins | 2007 |
Chronic lithium administration attenuates up-regulated brain arachidonic acid metabolism in a rat model of neuroinflammation.
Neuroinflammation, caused by a 6-day intracerebroventricular infusion of lipopolysaccharide (LPS) in rats, is associated with the up-regulation of brain arachidonic acid (AA) metabolism markers. Because chronic LiCl down-regulates markers of brain AA metabolism, we hypothesized that it would attenuate increments of these markers in LPS-infused rats. Incorporation coefficients k* of AA from plasma into brain, and other brain AA metabolic markers, were measured in rats that had been fed a LiCl or control diet for 6 weeks, and subjected in the last 6 days on the diet to intracerebroventricular infusion of artificial CSF or of LPS. In rats on the control diet, LPS compared with CSF infusion increased k* significantly in 28 regions, whereas the LiCl diet prevented k* increments in 18 of these regions. LiCl in CSF infused rats increased k* in 14 regions, largely belonging to auditory and visual systems. Brain cytoplasmic phospholipase A(2) activity, and prostaglandin E(2) and thromboxane B(2) concentrations, were increased significantly by LPS infusion in rats fed the control but not the LiCl diet. Chronic LiCl administration attenuates LPS-induced up-regulation of a number of brain AA metabolism markers. To the extent that this up-regulation has neuropathological consequences, lithium might be considered for treating human brain diseases accompanied by neuroinflammation. Topics: Animals; Anti-Inflammatory Agents; Antimanic Agents; Arachidonic Acid; Biomarkers; Brain; Dinoprostone; Disease Models, Animal; Down-Regulation; Drug Administration Schedule; Encephalitis; Lipopolysaccharides; Lithium Chloride; Male; Phospholipases A; Rats; Rats, Inbred F344; Thromboxane B2; Treatment Outcome; Up-Regulation | 2007 |
Identification of potential therapeutic drugs for huntington's disease using Caenorhabditis elegans.
The prolonged time course of Huntington's disease (HD) neurodegeneration increases both the time and cost of testing potential therapeutic compounds in mammalian models. An alternative is to initially assess the efficacy of compounds in invertebrate models, reducing time of testing from months to days.. We screened candidate therapeutic compounds that were identified previously in cell culture/animal studies in a C. elegans HD model and found that two FDA approved drugs, lithium chloride and mithramycin, independently and in combination suppressed HD neurotoxicity. Aging is a critical contributor to late onset neurodegenerative diseases. Using a genetic strategy and a novel assay, we demonstrate that lithium chloride and mithramycin remain neuroprotective independent of activity of the forkhead transcription factor DAF-16, which mediates the effects of the insulin-like signaling pathway on aging.. These results suggest that pathways involved in polyglutamine-induced degeneration are distinct from specific aging pathways. The assays presented here will be useful for rapid and inexpensive testing of other potential HD drugs and elucidating pathways of drug action. Additionally, the neuroprotection conferred by lithium chloride and mithramycin suggests that these drugs may be useful for polyglutamine disease therapy. Topics: Aging; Animals; Caenorhabditis elegans; Caenorhabditis elegans Proteins; Disease Models, Animal; Drug Combinations; Forkhead Transcription Factors; Huntington Disease; Lithium Chloride; Longevity; Neuroprotective Agents; Peptides; Plicamycin; Transcription Factors | 2007 |
An enriched environment improves cognitive performance after early-life status epilepticus accompanied by an increase in phosphorylation of extracellular signal-regulated kinase 2.
An enriched environment can enhance brain recovery in animals with early-life status epilepticus (SE). The purpose of this study was to determine the effects of early-life SE on spatial memory and hippocampal extracellular signal-regulated kinase (ERK) level, and the possible therapeutic effects of the enriched environment. Rats were assigned randomly to four groups: (1) control rats (nonenriched control); (2) control rats housed in an enriched environment from Postnatal Day (P) 25 to P40 (enriched control); (3) rats in which SE was induced with lithium-pilocarpine (Li-PC) at P21 (nonenriched SE); and (4) rats in which SE was induced with Li-PC at P21 and then housed in an enriched environment from P25 to P40 (enriched SE). As adults, the rats underwent spatial learning and memory tests in the Morris water maze between P50 and P55. At P55, subsets of animals were evaluated for expression of hippocampal ERK1/2 phosphorylation immediately following completion of the Morris water maze. At ~P100, another set of animals was tested for seizure threshold. When studied as adults, only the nonenriched SE group had a spatial memory deficit. The nonenriched SE group also exhibited lower levels of phosphorylated ERK2 as compared with the nonenriched control, enriched control, and enriched SE groups. Both the nonenriched SE and enriched SE groups had reduced seizure thresholds as compared with the nonenriched control and enriched control groups. Results from this study demonstrate that an enriched environment improves spatial memory in rats subjected to early-life SE, possibly through upregulation of phosphorylated ERK2 in the hippocampus. However, an enriched environment has no effect on seizure threshold. Topics: Analysis of Variance; Animals; Animals, Newborn; Behavior, Animal; Cognition; Disease Models, Animal; Environment; Hippocampus; Lithium Chloride; Male; Maze Learning; Mitogen-Activated Protein Kinase 1; Phosphorylation; Pilocarpine; Rats; Rats, Sprague-Dawley; Spatial Behavior; Status Epilepticus; Time Factors | 2007 |
Pathogenesis and pharmacology of epilepsy in the lithium-pilocarpine model.
To try to identify the critical structures during epileptogenesis, we used the lithium-pilocarpine model that reproduces most clinical and neuropathological features of temporal lobe epilepsy (TLE). We used imaging techniques as well as a disease modifying approach and pharmacological strategy. With [14C]-2-deoxyglucose autoradiography, we assessed changes in cerebral glucose utilization. T2-weighted magnetic resonance imaging (MRI, 4.7 T) allowed follow-up of structures involved in epileptogenesis. A potential disease-modifying effect was studied using preconditioning with brief seizures (amygdala kindling, maximal electroshocks) and pharmacological strategies including vigabatrin (250 mg/kg), caffeine (0.3 g/L in drinking water), topiramate (10-60 mg/kg), pregabalin (50 mg/kg followed by 10 mg/kg), or RWJ-333369 (10-120 mg/kg). In adult and PN21 rats that became epileptic, entorhinal, and piriform cortices were the initial structures exhibiting significant signal changes on MRI scans, from 6 h after status epilepticus (SE) onset, reflecting neuronal death. In PN21 rats that did not become epileptic, no signal occurred in parahippocampal cortices. In hippocampus, MRI signal change appeared 36-48 h after SE, and progressively worsened to sclerosis. During the latent and chronic phases, the metabolic level in the hilus of adult and PN21 epileptic rats was normal although neuronal loss reached 60-75%. Protection limited to CA1 and/or CA3 (caffeine, topiramate, vigabatrin, amygdala kindling) did not affect the latency to spontaneous seizures. Protection limited to the entorhinal and piriform cortices (pregabalin) delayed epileptogenesis. The combined protection of Ammon's horn and parahippocampal cortices (RWJ-333369) prolonged the latency before the onset of seizures in a dose-dependent manner or, in some cases, prevented the epilepsy. The entorhinal and piriform cortices are critically involved in the early phase of the epileptogenesis while the hilus may initiate and/or maintain epileptic seizures. Pharmacological protection of the basal cortices is necessary for a beneficial disease-modifying effect but this must be combined with protection of the hippocampus to prevent epileptogenesis in this model of TLE. Topics: Animals; Animals, Newborn; Anticonvulsants; Autoradiography; Cell Count; Cerebral Cortex; Deoxyglucose; Disease Models, Animal; Electroencephalography; Electroshock; Entorhinal Cortex; Epilepsy, Temporal Lobe; Fructose; Glucose; Hippocampus; Kindling, Neurologic; Lithium Chloride; Magnetic Resonance Imaging; Olfactory Pathways; Pilocarpine; Rats; Rats, Sprague-Dawley; Status Epilepticus; Topiramate; Vigabatrin | 2007 |
Effects of LiCl/pilocarpine-induced status epilepticus on rat brain mu and benzodiazepine receptor binding: regional and ontogenetic studies.
Neurochemical studies document involvement of benzodiazepine (BDZ) and mu opioid receptors in seizure development and their possible age-related role during epileptogenesis. To study developmental changes of this role LiCl/pilocarpine status epilepticus (SE) was induced in P12, P25 and/or adult rats. This SE leads to epilepsy in all adult and subpopulation of immature rats. Using in vitro autoradiography, benzodiazepine (BDZ) and mu opioid receptor binding was evaluated 1 week (early phase of epileptogenesis) and 3 months (chronic phase) after SE in 27 brain structures involved in seizure generation and spread (amygdala, hippocampus, basal ganglia and thalamic nuclei). The pattern of receptor binding changes was related to the age at SE, interval after SE and to brain structures. Enhanced BDZ binding was found 1 week after SE in many cortical areas in P12 and also in the amygdala complex and dentate gyrus in both P12 and P25. No changes of BDZ binding occurred in adults at that time, but 3 months after SE a decrease of binding appeared in all evaluated areas in both adult and P25 but not P12 rats. This decrease did not reflect neuronal loss. mu opioid receptors were less significantly affected but clear tendency to decrease binding occurred in adult rats in various cortical, amygdala and thalamic regions early after SE. Changes were less expressed in immature rats. Our data support the hypothesis that age-related changes of receptor properties may participate in different functional consequences of SE including epileptogenesis (more common in older age groups) and behavioral changes. Topics: Age Factors; Analysis of Variance; Animals; Brain; Disease Models, Animal; Lithium Chloride; Pilocarpine; Rats; Rats, Wistar; Receptors, GABA-A; Receptors, Opioid, mu; Statistics, Nonparametric; Status Epilepticus; Time Factors | 2007 |
Inflammation modifies status epilepticus-induced hippocampal injury during development.
Topics: Animals; Animals, Newborn; Brain; Disease Models, Animal; Hippocampus; Inflammation; Kainic Acid; Lipopolysaccharides; Lithium Chloride; Neurons; Pilocarpine; Rats; Status Epilepticus | 2007 |
Delta-9-tetrahydrocannabinol and cannabidiol, but not ondansetron, interfere with conditioned retching reactions elicited by a lithium-paired context in Suncus murinus: An animal model of anticipatory nausea and vomiting.
Chemotherapy patients report not only acute nausea and vomiting during the treatment itself, but also report anticipatory nausea and vomiting upon re-exposure to the cues associated with the treatment. We present a model of anticipatory nausea based on the emetic reactions of the Suncus murinus (musk shrew). Following three pairings of a novel distinctive contextual cue with the emetic effects of an injection of lithium chloride, the context acquired the potential to elicit conditioned retching in the absence of the toxin. The expression of this conditioned retching reaction was completely suppressed by pretreatment with each of the principal cannabinoids found in marijuana, Delta(9)-tetrahydrocannabinol or cannabidiol, at a dose that did not suppress general activity. On the other hand, pretreatment with a dose of ondansetron (a 5-HT(3) antagonist) that interferes with acute vomiting in this species, did not suppress the expression of conditioned retching during re-exposure to the lithium-paired context. These results support anecdotal claims that marijuana, but not ondansetron, may suppress the expression of anticipatory nausea. Topics: Analysis of Variance; Animals; Antiemetics; Association Learning; Cannabidiol; Cannabinoids; Conditioning, Classical; Disease Models, Animal; Dronabinol; Female; Lithium Chloride; Male; Nausea; Ondansetron; Serotonin Antagonists; Shrews; Vomiting, Anticipatory | 2006 |
Status epilepticus in 12-day-old rats leads to temporal lobe neurodegeneration and volume reduction: a histologic and MRI study.
Whether status epilepticus (SE) in early infancy, rather than the underlying illness, leads to temporal lobe neurodegeneration and volume reduction remains controversial.. SE was induced with LiCl-pilocarpine in P12 rats. To assess acute neuronal damage, brains (five controls, five with SE) were investigated at 8 h after SE by using silver and Fluoro-Jade B staining. Some brains from the early phase were processed for electron microscopy. To assess chronic changes, brains from nine controls and 13 rats with SE at P12 were analyzed after 3 months by using histology and magnetic resonance imaging (MRI).. MRI analysis of the temporal lobe of adult animals with SE at P12 indicated that 23% of the rats had hippocampal, 15% had amygdaloid, and 31% had perirhinal volume reduction. Histologic analysis of sections from the MR-imaged brains correlated with the MRI data. Analysis of neurodegeneration 8 h after SE by using both silver and Fluoro-Jade B staining revealed degenerating neurons located in the same temporal lobe regions as the volume reduction in chronic samples. Electron microscopic analysis revealed irreversible ultrastructural alterations. As with the chronic histologic and MRI findings, interanimal variability was seen in the distribution and severity of acute damage.. Our data indicate that SE at P12 can cause acute neurodegeneration in the hippocampus as well as in the adjacent temporal lobe. It is likely that acute neuronal death contributes to volume reduction in temporal lobe regions that is detected with MRI in a subpopulation of animals in adulthood. Topics: Amygdala; Animals; Animals, Newborn; Apoptosis; Disease Models, Animal; Entorhinal Cortex; Fluoresceins; Hippocampus; Lithium Chloride; Magnetic Resonance Imaging; Male; Microscopy, Electron; Nerve Degeneration; Neurons; Organic Chemicals; Pilocarpine; Rats; Rats, Wistar; Silver Staining; Status Epilepticus; Temporal Lobe | 2006 |
Lithium-induced activation of Akt and CaM kinase II contributes to its neuroprotective action in a rat microsphere embolism model.
Lithium used in bipolar mood disorder therapy protects neurons from brain ischemic cell death. Here, we documented that lithium administration under microsphere-embolism (ME)-induced brain ischemia restored decreased protein kinase B (Akt) and Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) activities 24 h after ischemia in rat brain. Akt activation was associated with increased phosphorylation of its potential targets forkhead transcription factor (FKHR) and glycogen synthase kinase-3beta (GSK-3beta). In parallel with decreased CaMKII autophosphorylation, we also found marked dephosphorylation of tau proteins 24-72 h after ME. Increased protein phosphatase 2A (PP2A) activity was found 24 h after ME. Inhibition of increased PP2A activity by lithium treatment apparently mediated restored tau phosphorylation. Taken together, activation of Akt and CaMKII by lithium was associated with neuroprotective activity in ME-induced neuronal injury. Topics: Animals; Antimanic Agents; Brain Infarction; Brain Ischemia; Calcium-Calmodulin-Dependent Protein Kinase Type 2; Calcium-Calmodulin-Dependent Protein Kinases; Disease Models, Animal; Enzyme Activation; Forkhead Transcription Factors; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Intracranial Embolism; Lithium Chloride; Male; Nerve Tissue Proteins; Neuroprotective Agents; Phosphoprotein Phosphatases; Protein Phosphatase 2; Proto-Oncogene Proteins c-akt; Rats; Rats, Wistar; Serine; tau Proteins; Up-Regulation | 2006 |
Long-term alterations in glutamate receptor and transporter expression following early-life seizures are associated with increased seizure susceptibility.
Prolonged seizures in early childhood are associated with an increased risk of development of epilepsy in later life. The mechanism(s) behind this susceptibility to later development of epilepsy is unclear. Increased synaptic activity during development has been shown to permanently alter excitatory neurotransmission and could be one of the mechanisms involved in this increased susceptibility to the development of epilepsy. In the present study we determine the effect of status-epilepticus induced by lithium/pilocarpine at postnatal day 10 (P10 SE) on the expression of glutamate receptor and transporter mRNAs in hippocampal dentate granule cells and protein levels in dentate gyrus of these animals in adulthood. The results revealed a decrease in glutamate receptor 2 (GluR2) mRNA expression and protein levels as well as an increase in protein levels for the excitatory amino acid carrier 1 (EAAC1) in P10 SE rats compared to controls. Expression of glutamate receptor 1 (GluR1) mRNA was decreased in both P10 SE rats and identically handled, lithium-injected littermate controls compared to naive animals, and GluR1 protein levels were significantly lower in lithium-controls than in naive rats, suggesting an effect of either the handling or the lithium on GluR1 expression. These changes in EAA receptors and transporters were accompanied by an increased susceptibility to kainic acid induced seizures in P10 SE rats compared to controls. The current data suggest that early-life status-epilepticus can result in permanent alterations in glutamate receptor and transporter gene expression, which may contribute to a lower seizure threshold. Topics: Amino Acid Transport System X-AG; Animals; Cell Separation; Convulsants; Dentate Gyrus; Disease Models, Animal; Disease Susceptibility; Excitatory Amino Acid Transporter 2; Excitatory Amino Acid Transporter 3; Glutamate Plasma Membrane Transport Proteins; Handling, Psychological; Lithium Chloride; Male; Neurons; Pilocarpine; Rats; Receptors, AMPA; Receptors, Glutamate; RNA, Messenger; Seizures; Status Epilepticus; Symporters; Time | 2004 |
The neuromatrix and the epileptic brain: behavioral and learning preservation in limbic epileptic rats treated with ketamine but not acepromazine.
Conceiving the organization of the brain as a "neuromatrix" could provide significant insights into how different injuries to the nervous system could result in very distinct changes in behavior. The use of different pharmacological treatments to combat the deleterious consequences of such injuries is common practice. However, such treatments may have the capacity to alter the configurations of various neuronal circuits that contribute to the "neuromatrix" by selectively preventing damage to some pathways while facilitating the spread of destruction along others. The choice of pharmacological treatment may have profound consequences on the recovery of normal functioning following injury. We examined the behavior of rats treated with one of two potentially neuroprotective agents, the N-methyl-D-aspartate antagonist ketamine and the atypical neuroleptic acepromazine, on seizures induced by lithium-pilocarpine. Rats treated with ketamine following seizure onset were virtually indistinguishable from nonepileptic controls on a variety of behavioral tasks that included tests on learning, memory, and anxiety. In contrast, acepromazine-treated rats showed marked deficits on all learning and behavioral measures tested. These results suggest that administration of ketamine relatively soon after the emergence of epilepsy can prevent many of the cognitive deficits that are commonly found in rats subjected to lithium-pilocarpine-induced seizures. Further clinical testing investigating ketamine as a potential adjunct treatment for epilepsy may be well warranted. Topics: Acepromazine; Analysis of Variance; Animals; Antipsychotic Agents; Behavior, Animal; Brain; Chi-Square Distribution; Conditioning, Psychological; Disease Models, Animal; Epilepsy; Escape Reaction; Excitatory Amino Acid Antagonists; Exploratory Behavior; Fear; Ketamine; Lithium Chloride; Male; Maze Learning; Rats; Rats, Wistar; Seizures; Time Factors | 2004 |
Lithium treatment enhances estradiol-induced proliferation and hyperplasia formation in the uterus of mice.
It is suggested that the Wnt/beta-catenin pathway plays a role in the regulation of estrogen action in the uterus. However, this suggestion has not been proved. Lithium can mimic increased activity of the Wnt/beta-catenin pathway by blocking the activity of glycogen synthase kinase-3beta. There are no data on the effects of lithium on estrogen-dependent processes in the uterus. This work was therefore aimed to examine the action of lithium on proliferative and morphogenetic reactions in the uterus under short- and long-term estrogen treatments.. Ovariectomized mice received estradiol dipropionate (2 microg per 100g; s.c.) once a week or vehicle and drank tap water with 0.05% lithium chloride or plain tap water for 2 or 30 days.. In animals treated with estradiol and lithium for a month, the incidence of atypical endometrial hyperplasia was significantly higher. In animals treated with estradiol and lithium for 2 days or for a month, uterine mass, the number of mitotic cells and BrdU-labelled cells in luminal epithelium, glandular epithelium, stromal and myometrial cells was markedly greater, whereas the levels of estrogen receptors-alpha, beta-catenin and glycogen synthase kinase-3beta were markedly lower in all uterine compartments, than in those in mice received estradiol with no lithium to drink.. Lithium treatment results in an increase in estradiol-induced proliferative and morphogenetic changes in the uterus. This action of lithium is associated with decreased expression of estrogen receptors-alpha, beta-catenin and glycogen synthase kinase-3beta in the uterus. Topics: Administration, Oral; Animals; beta Catenin; Cytoskeletal Proteins; Disease Models, Animal; Endometrial Hyperplasia; Estradiol; Female; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Injections, Subcutaneous; Lithium Chloride; Mice; Ovariectomy; Random Allocation; Receptors, Estrogen; Trans-Activators; Uterus | 2004 |
Lithium ion "cyclotron resonance" magnetic fields decrease seizure onset times in lithium-pilocarpine seized rats.
The cyclotron resonance equation predicts that the frequency of an applied magnetic field that might optimally interact with a single ion species may be computed as a function of the charge-to-mass ratio of the ion and the strength of the background static magnetic field. The present study was undertaken to discern the applicability of this equation for optimizing lithium ion utilization in the rat, as inferred by the predicted magnetic "ion resonance "field-induced shift of lithium's dose-dependent curve for seizure onset times (SOTs) when combined with the cholinergic agent pilocarpine. Groups of rats were administered 1.5 thru 3 mEq/kg lithium chloride (in 0.5 mEq/kg increments) and exposed to reference conditions or to one of three intensities (70 nanoTesla, 0.8 microTesla, or 25 microTesla) of a 85 Hz magnetic field calculated to resonate with lithium ions given the background static geomagnetic field of approximately 38,000 nanoTesla (0.38 Gauss). A statistically significant quadratic relationship for SOT as a function of magnetic field intensity (irrespective of lithium dose) was noted: this U-shaped function was characterized by equal SOTs for the reference and 25 microTesla groups, with a trend toward shorter SOTs for the 70 nanoTesla and 0.8 microTesla groups. Although not predicted by the equations, this report extends other findings suggestive of discrete intensity windows for which magnetic field frequencies derived from the cyclotron ion resonance equation may affect ion activity. Topics: Analysis of Variance; Animals; Cyclotrons; Disease Models, Animal; Dose-Response Relationship, Drug; Dose-Response Relationship, Radiation; Electromagnetic Fields; Lithium; Lithium Chloride; Magnetic Resonance Spectroscopy; Male; Pilocarpine; Rats; Rats, Wistar; Seizures; Time Factors | 2004 |
Anxiety-like state associates with taste to produce conditioned taste aversion.
The interactions among experience, emotion, and memory are considered to be instrumental in the ontogeny and maintenance of acquired emotional and behavioral disorders (e.g., phobias). Here we address the question whether an anxiety-like state can associate with taste to produce conditioned taste aversion (CTA).. We have used an anxiogenic agent, the 5-HT2C receptor agonist meta-chlorophenylpiperazine (mCPP), to induce an anxiety-like emotional state in rats after consumption of an unfamiliar tastant.. The anxiogenic agent induced CTA. The mCPP-induced CTA could be prevented by concomitant administration of ethanol, which is known to reverse mCPP-induced anxiety-like behavior, at a concentration that had no effect on CTA memory. In contrast, ethanol did not prevent LiCl-induced CTA. Administration of mCPP before the consumption of the tastant had no effect on the preference for that tastant.. Taken together, these results indicate that anxiety-like state can serve as the unconditioned stimulus in CTA training. This finding may be relevant to the ontogeny of pathologies involving food aversion. Topics: Animals; Anxiety; Avoidance Learning; Behavior, Animal; Central Nervous System Depressants; Conditioning, Psychological; Disease Models, Animal; Drug Interactions; Ethanol; Glycine; Lithium Chloride; Male; Piperazines; Rats; Rats, Wistar; Saccharin; Taste; Time Factors | 2004 |
Vestibular lesions selectively abolish body rotation-induced, but not lithium-induced, conditioned taste aversions (oral rejection responses) in rats.
Pairing a novel taste with provocative vestibular stimulation results in conditioned taste aversions in both rats and humans. Vestibular system involvement in gustatory conditioning was examined in sham-lesioned or labyrinthectomized rats. Three conditioning trials consisted of 30 min access to asaccharin (0.1%) solution followed by 30 min of rotation (70 rpm) or sham rotation. In a taste reactivity test with saccharin, rotated sham-lesioned rats, but not labyrinthectomized rats, exhibited increased oral rejection reactions compared with control rats. When conditioned with lithium chloride, both labyrinthectomized and sham-lesioned rats displayed robust conditioned rejection reactions. The finding that normal vestibular function is necessary in obtaining rotation-induced conditioned taste aversions supports the face and construct validity of a rat model of motion sickness. Topics: Animals; Antimanic Agents; Avoidance Learning; Conditioning, Classical; Disease Models, Animal; Lithium Chloride; Male; Motion Sickness; Motor Activity; Rats; Rats, Sprague-Dawley; Taste; Vestibule, Labyrinth | 2003 |
Prolonged low-dose caffeine exposure protects against hippocampal damage but not against the occurrence of epilepsy in the lithium-pilocarpine model in the rat.
Acute caffeine exposure has proconvulsant effects and worsens epileptic and ischemic neuronal damage. Surprisingly, prolonged caffeine exposure decreases the susceptibility to seizures and the extent of ischemic damage. We explored whether the exposure to a low long-term dose of caffeine could protect the brain from neuronal damage and epileptogenesis in the lithium-pilocarpine model of temporal lobe epilepsy.. Rats received either plain tap water or water containing caffeine (0.3 g/L) for 15 days before the induction of status epilepticus (SE) by lithium-pilocarpine and for 7 days after SE. The extent of neuronal damage was assessed in the hippocampus and piriform and entorhinal cortices in brain sections stained with thionine and obtained from animals killed 7 days after SE. The latency to spontaneous recurrent seizures was controlled by video monitoring.. Caffeine treatment induced a marked, almost total neuroprotection in CA1 and a very limited protection in the hilus of the dentate gyrus, whereas damage in layers III-IV of the piriform cortex was slightly worsened by the treatment. All rats, whether they received caffeine or plain tap water, became epileptic after the same latency (17-19 days).. Thus these data extend the neuroprotective effects of low long-term caffeine exposure to epileptic damage and confirm that the sole protection of the Ammon's horn has no influence on the genesis of spontaneous recurrent seizures in this model. Topics: Age Factors; Animals; Anticonvulsants; Apoptosis; Caffeine; Convulsants; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Administration Schedule; Hippocampus; Kindling, Neurologic; Lithium Chloride; Male; Maze Learning; Mossy Fibers, Hippocampal; Nerve Regeneration; Neuroprotective Agents; Orientation; Pilocarpine; Rats; Rats, Sprague-Dawley; Status Epilepticus | 2003 |
Chronic lithium chloride treatment has variable effects on motor behaviour and survival of mice transgenic for the Huntington's disease mutation.
Expression of the Huntington's disease (HD) mutation in mice (R6/2 line) causes a progressive neurological phenotype that includes deterioration of motor function resembling that seen in HD. The current study sought to determine whether or not chronic treatment of R6/2 mice with lithium chloride would have an effect on the progression of the phenotype, in light of lithium's reported neuroprotective and anti-depressive properties. Treatment began either before or after the onset of symptoms. Chronic treatment with lithium caused a significant improvement in rotarod performance when treatment was started post- but not pre-symptomatically. There was no overall effect on survival in either group, but further analysis revealed that in the post-symptomatic group, mice could be assigned to one of two distinct groups, depending on the effects of lithium. One subgroup of mice lost weight faster, died earlier and showed rotarod performance similar to the vehicle-treated controls. The other subgroup lost weight at a normal rate, died at a similar age, but showed greatly improved motor performance compared to controls. The improvement in rotarod performance suggests that lithium may improve motor symptoms as well as depression in some HD patients. Topics: Aging; Animals; Antimanic Agents; Behavior, Animal; Body Weight; Disease Models, Animal; Drug Administration Routes; Female; Huntington Disease; Lithium Chloride; Male; Mice; Mice, Inbred C57BL; Mice, Transgenic; Motor Activity; Mutation; Norbornanes; Phenotype; Psychomotor Performance; Rotation; Survival; Time Factors | 2003 |
Increased persistent sodium currents in rat entorhinal cortex layer V neurons in a post-status epilepticus model of temporal lobe epilepsy.
Spontaneous seizures in rats emerge several weeks after induction of status epilepticus with pharmacologic treatment or electrical stimulation, providing an animal model for human temporal lobe epilepsy. In this study, we investigated whether status epilepticus caused changes in the function of voltage-gated sodium channels in entorhinal cortex layer V neurons, a cellular group important for the genesis of limbic seizures.. We induced status epilepticus in rats, by using lithium-pilocarpine, and then 2-12 weeks later, used whole-cell voltage-clamp to examine voltage-activated sodium currents of acutely dissociated layer V neurons.. Transient sodium currents of entorhinal cortex layer V neurons isolated from 9- to 12-week post-status epilepticus rats were similar to currents in age-matched controls; however, low-threshold persistent sodium currents were significantly larger. This increase in persistent activity was not seen 2-3 weeks after pilocarpine treatment; thus it occurred after a delay comparable to the delay in the appearance of spontaneous seizures.. Increased persistent currents are expected to accentuate neuronal excitability and thus may contribute to the genesis of spontaneous seizures after status epilepticus. Topics: Animals; Cells, Cultured; Disease Models, Animal; Entorhinal Cortex; Epilepsy, Temporal Lobe; Kindling, Neurologic; Lithium Chloride; Male; Membrane Potentials; Neurons; Patch-Clamp Techniques; Pilocarpine; Rats; Rats, Long-Evans; Sodium Channels; Status Epilepticus | 2003 |
Characterization of pharmacoresistance to benzodiazepines in the rat Li-pilocarpine model of status epilepticus.
Status epilepticus is usually initially treated with a benzodiazepine such as diazepam. During prolonged seizures, however, patients often lose their sensitivity to benzodiazepines, thus developing pharmacoresistant seizures. In rats, administration of LiCl followed 20-24 h later by pilocarpine induces a continuous, self-sustained, and reproducible form of status epilepticus that can be terminated with diazepam when it is administered soon after the pilocarpine injection. However, when administered after a 45 min delay, diazepam is less effective. Previous findings have suggested that the development of pharmacoresistance is related to the stage of status epilepticus. In the present study, we characterized the seizure stage-dependence of diazepam pharmacoresistance. Following administration of different doses of diazepam at varying time intervals after specific behaviorally- and electrographically-defined seizure stages, stage-, time-, and dose-dependent pharmacoresistance to diazepam developed. We also studied two other antiepileptic drugs commonly used in the treatment of status epilepticus, phenobarbital and phenytoin. Consistent with previous studies, our results indicated a similar relationship between stage, time and dose for phenobarbital, but not for phenytoin. Our data are consistent with rapid modulation of GABA(A) receptors during status epilepticus that may result in pharmacoresistance to antiepileptic drugs that enhance GABA(A) receptor-mediated inhibition. Topics: Animals; Anticonvulsants; Benzodiazepines; Chi-Square Distribution; Diazepam; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Resistance; Electroencephalography; Lithium Chloride; Male; Muscarinic Agonists; Phenobarbital; Phenytoin; Pilocarpine; Rats; Rats, Sprague-Dawley; Receptors, GABA-A; Status Epilepticus; Time Factors | 2002 |
Predictive value of cortical injury for the development of temporal lobe epilepsy in 21-day-old rats: an MRI approach using the lithium-pilocarpine model.
Patients with temporal lobe epilepsy (TLE) usually had an initial precipitating injury in early childhood. However, epilepsy does not develop in all children who have undergone an early insult. As in patients, the consequences of the lithium-pilocarpine-induced status epilepticus (SE) are age dependent, and only a subset of 21-day-old rats will develop epilepsy. Thus with magnetic resonance imaging (MRI), we explored the differences in the evolution of lesions in these two populations of rats.. SE was induced in 21-day-old rats by the injection of lithium and pilocarpine. T2-weighted images and T2 relaxation-time measurements were used for detection of lesions from 6 h to 4 months after SE.. Three populations of rats could be distinguished. The first one had neither MRI anomalies nor modification of the T2 relaxation time, and these rats did not develop epilepsy. In the second one, a hypersignal appeared at the level of the piriform and entorhinal cortices 24 h after SE (increase of 49% of the T2 relaxation time in the piriform cortex) that began to disappear 48-72 h after SE; epilepsy developed in all these animals. The third population of rats showed a more moderate increase of the T2 relaxation time in cortices (14% in the piriform cortex) that could not be seen on T2-weighted images. Epilepsy developed in all these rats. Only in a subpopulation of the 21-day-old rats with epilepsy did hippocampal sclerosis develop.. These results suggest that the injury of the piriform and entorhinal cortices during SE play a critical role for the installation of the epileptic networks and the development of epilepsy. Topics: Age Factors; Animals; Brain Diseases; Cerebral Cortex; Disease Models, Animal; Entorhinal Cortex; Epilepsy, Temporal Lobe; Female; Lithium Chloride; Magnetic Resonance Imaging; Male; Pilocarpine; Probability; Rats; Rats, Sprague-Dawley; Status Epilepticus | 2002 |
The effects of lithium chloride and other substances on levels of brain N-acetyl-L-aspartic acid in Canavan disease-like rats.
Canavan disease (CD) is a human early-onset leukodystrophy, genetic in nature and resulting from an autosomally inherited recessive trait. CD is characterized by loss of the axon's myelin sheath, while leaving the axons intact, and spongiform degeneration, especially in white matter. It is an osmotic disease that affects both gray and white matter and is caused by the inability of oligodendrocytes to hydrolyze N-acetyl-L-aspartate (NAA) because of a lack of aspartoacylase activity. As a result, there is a build-up of NAA in brain with both cellular and extracellular edema, as well as NAA acidemia and NAA aciduria. Recent studies have indicated that several compounds have the ability to reduce brain levels of NAA in normal mice and rats. In this investigation, these compounds have been tested, using a CD-like rat model of the human disease to evaluate their potential for use in the treatment of the disease. Of seven substances tested in an acute 5-day study, only lithium chloride treatment resulted in a significant reduction of about 13% in whole-brain NAA levels in the CD-like rat model. This is the first pharmacological investigation of the effect of drugs on the level of brain NAA in an animal model of CD, and the first report of a substance that can reduce the brain NAA level in this model. Topics: Animals; Aspartic Acid; Blood-Brain Barrier; Brain; Canavan Disease; Disease Models, Animal; Lithium Chloride; Male; Rats; Rats, Mutant Strains | 2002 |
Changed concentrations of tachykinins and neuropeptide Y in brain of a rat model of depression: lithium treatment normalizes tachykinins.
Lithium's therapeutic mechanism of action is unknown. In lithium-treated normal rats, increased striatal concentrations of neurokinin A (NKA)-like immunoreactivity (LI), substance P (SP-LI) and neuropeptide Y (NPY-LI) have been reported. To investigate whether these effects might be of therapeutic relevance, Flinders Sensitive Line rats (FSL), an animal model of depression, and control Flinders Resistant Line (FRL) rats were during a 6-week period fed chow to which either lithium or vehicle was admixed. Following sacrifice, the peptides were extracted from dissected brain regions and measured by radioimmunoassay. NKA-LI and SP-LI were markedly decreased in striatum and increased in frontal cortex in FSL compared to control FRL animals. Lithium treatment abolished these differences. Basal concentrations of NPY-LI were decreased in hippocampus of FSL rats, but unaffected by lithium. The present study suggests that changed tachykinins and NPY may underlie the characterized depressive-like phenotype of the FSL rats. It is hypothesized that altering tachykinin peptidergic neurotransmission in striatum and frontal cortex constitutes a mechanism of action of lithium and that such a mechanism might be of therapeutic relevance. Topics: Animals; Brain; Depression; Disease Models, Animal; Lithium Chloride; Male; Neuropeptide Y; Rats; Species Specificity; Tachykinins | 2001 |
Differential sensitivity to lithium's reversal of amphetamine-induced open-field activity in two inbred strains of mice.
To determine whether genetic differences could contribute to the pharmacological sensitivity of lithium chloride (LiCl) to reverse amphetamine-associated changes in behavior C57BL/6nCrlBR and C3H/HenCrlBR male mice were tested for the ability of an acute dose of LiCl to reverse the locomotor enhancing effects of an acute dose of amphetamine. A series of experiments were conducted that compared dose response of LiCl, chamber lighting conditions, and chamber shape on amphetamine-induced activity in two strains of mice with different genetic backgrounds. Acute amphetamine (3 mg/kg) increased locomotor activity in C57BL/6nCrlBR mice and LiCl (1-4 mEq/kg) blocked this effect. LiCl-induced changes in baseline activity seen at high doses of LiCl were not seen for the low doses. The dark condition reduced time resting but chamber shape did not appear to alter results. In C3H/HenCrlBR mice, amphetamine did not significantly increase levels of activity but did decrease rearing behavior which suggests that genetic difference between C57BL/6nCrlBR and C3H/HenCrlBR mice may contribute to sensitivity to amphetamine. In sum, the ability of LiCl to reverse amphetamine-induced changes in locomotor activity in C57BL/6nCrlBR mice may provide a useful model to study genetic and pharmacological aspects of psychiatric illnesses such as bipolar disorder. Topics: Amphetamines; Analysis of Variance; Animals; Antimanic Agents; Bipolar Disorder; Central Nervous System Stimulants; Disease Models, Animal; Drug Evaluation; Lithium Chloride; Male; Mice; Mice, Inbred C3H; Mice, Inbred C57BL; Motor Activity | 2001 |
An animal model of nonconvulsive status epilepticus: a contribution to clinical controversies.
To characterize electroencephalographic and behavioral effects as well as electrophysiologic and morphologic consequences of a subconvulsive dose of pilocarpine in lithium chloride-pretreated rats.. Pilocarpine (15 mg/kg) was administered intraperitoneally to adult rats pretreated with lithium chloride (3 mEq/kg, i.p.). Behavior was observed for 2 h and videotaped in three consecutive sessions. At the same time, EEG was recorded from the sensorimotor cortex and the dorsal hippocampus. Threshold intensities of currents necessary to elicit hippocampal afterdischarges were determined 24 h and 1 week after the pilocarpine administration. The brains were histologically examined 1 week after pilocarpine administration using Nissl stain.. Pilocarpine induced time-limited nonconvulsive status epilepticus (NCSE). Epileptic EEG activity concurrent with prominent behavioral features was observed both in the neocortex and, predominantly, in the hippocampus. No changes in afterdischarge thresholds were observed in the dorsal hippocampus 24 h and 1 week after NCSE. One week after NCSE, seizure-related brain damage was found mainly in the motor neocortical fields.. Pilocarpine-induced NCSE in rats strongly resembles a short-term human complex partial status epilepticus. Our animal model is suitable for studying the possible adverse effects of prolonged nonconvulsive seizures. Topics: Animals; Behavior, Animal; Disease Models, Animal; Electroencephalography; Hippocampus; Humans; Lithium Chloride; Male; Motor Activity; Neocortex; Pilocarpine; Rats; Rats, Wistar; Status Epilepticus; Videotape Recording | 2001 |
Status epilepticus causes necrotic damage in the mediodorsal nucleus of the thalamus in immature rats.
Status epilepticus (StE) in immature rats causes long-term functional impairment. Whether this is associated with structural alterations remains controversial. The present study was designed to test the hypothesis that StE at an early age results in neuronal loss. StE was induced with lithium-pilocarpine in 12-d-old rats, and the presence of neuronal damage was investigated in the brain from 12 hr up to 1 week later using silver and Fluoro-Jade B staining techniques. Analysis of the sections indicated consistent neuronal damage in the central and lateral segments of the mediodorsal nucleus of the thalamus, which was confirmed using adjacent cresyl violet-stained preparations. The mechanism of thalamic damage (necrosis vs apoptosis) was investigated further using TUNEL, immunohistochemistry for caspase-3 and cytochrome c, and electron microscopy. Activated microglia were detected using OX-42 immunohistochemistry. The presence of silver and Fluoro-Jade B-positive degenerating neurons in the mediodorsal thalamic nucleus was associated with the appearance of OX-42-immunopositive activated microglia but not with the expression of markers of programmed cell death, caspase-3, or cytochrome c. Electron microscopy revealed necrosis of the ultrastructure of damaged neurons, providing further evidence that the mechanism of StE-induced damage in the mediodorsal thalamic nucleus at postnatal day 12 is necrosis rather than apoptosis. Finally, these data together with previously described functions of the medial and lateral segments of the mediodorsal thalamic nucleus suggest that some functions, such as adaptation to novelty, might become compromised after StE early in development. Topics: Animals; Antigens, CD; Antigens, Neoplasm; Antigens, Surface; Apoptosis; Avian Proteins; Basigin; Blood Proteins; Caspase 3; Caspases; Cytochrome c Group; Disease Models, Animal; Disease Progression; Immunohistochemistry; In Situ Nick-End Labeling; Lithium Chloride; Male; Mediodorsal Thalamic Nucleus; Membrane Glycoproteins; Microglia; Microscopy, Electron; Necrosis; Neurons; Pilocarpine; Rats; Rats, Wistar; Status Epilepticus | 2001 |
Lithium suppresses excitotoxicity-induced striatal lesions in a rat model of Huntington's disease.
Huntington's disease is a progressive, inherited neurodegenerative disorder characterized by the loss of subsets of neurons primarily in the striatum. In this study, we assessed the neuroprotective effect of lithium against striatal lesion formation in a rat model of Huntington's disease in which quinolinic acid was unilaterally infused into the striatum. For this purpose, we used a dopamine receptor autoradiography and glutamic acid decarboxylase mRNA in situ hybridization analysis, methods previously shown to be adequate for quantitative analysis of the excitotoxin-induced striatal lesion size. Here we demonstrated that subcutaneous injections of LiCl for 16 days prior to quinolinic acid infusion considerably reduced the size of quinolinic acid-induced striatal lesion. Furthermore, these lithium pre-treatments also decreased the number of striatal neurons labeled with the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay. Immunohistochemistry and western blotting demonstrated that lithium-elicited neuroprotection was associated with an increase in Bcl-2 protein levels. Our results raise the possibility that lithium may be considered as a neuroprotective agent in treatment of neurodegenerative diseases such as Huntington's disease. Topics: Animals; Antimanic Agents; Benzazepines; Cell Death; Cyclin D1; Disease Models, Animal; Dopamine Antagonists; Glutamate Decarboxylase; Huntington Disease; Immunohistochemistry; In Situ Nick-End Labeling; Isoenzymes; Lithium; Lithium Chloride; Male; Neostriatum; Neurons; Neuroprotective Agents; Neurotoxins; Quinolinic Acid; Radioligand Assay; Rats; Rats, Sprague-Dawley; Receptors, Dopamine D1; RNA, Messenger | 2001 |
Influence of strain, sex and age on nephrotoxicity of lithium in a one-hour model in rats.
Topics: Age Factors; Animals; Antimanic Agents; Disease Models, Animal; Female; Kidney Diseases; Lithium Chloride; Male; Rats; Rats, Inbred Lew; Rats, Inbred Strains; Rats, Sprague-Dawley; Sex Factors; Species Specificity | 2001 |
Intrastriatal and intranigral grafting of hNT neurons in the 6-OHDA rat model of Parkinson's disease.
The clinical findings on neural transplantation for Parkinson's disease (PD) reported thus far are promising but many issues must be addressed before neural transplantation can be considered a routine therapeutic option for PD. The future of neural transplantation for the treatment of neurological disorders may rest in the discovery of a suitable alternative cell type for fetal tissue. One such alternative may be neurons derived from a human teratocarcinoma (hNT). hNT neurons have been shown to survive and integrate within the host brain following transplantation and provide functional recovery in animal models of stroke and Huntington's disease. In this study, we describe the transplantation of hNT neurons in the substantia nigra (SN) and striatum of the rat model for PD. Twenty-seven rats were grafted with one of three hNT neuronal products; hNT neurons, hNT-DA neurons, or lithium chloride (LiCl) pretreated hNT-DA neurons. Robust hNT grafts could be seen with anti-neural cell adhesion molecule and anti-neuron-specific enolase immunostaining. Immunostaining for tyrosine hydroxylase (TH) expression revealed no TH-immunoreactive (THir) neurons in any animals with hNT neuronal grafts. THir cells were observed in 43% of animals with hNT-DA neuronal grafts and all animals with LiCl pretreated hNT-DA neuronal grafts (100%). The number of THir neurons in these animals was low and not sufficient to produce significant functional recovery. In summary, this study has demonstrated that hNT neurons survive transplantation and express TH in the striatum and SN. Although hNT neurons are promising as an alternative to fetal tissue and may have potential clinical applications in the future, further improvements in enhancing TH expression are needed. Topics: Amphetamine; Animals; Cell Count; Cell Line; Corpus Striatum; Disease Models, Animal; Dopamine; Female; Graft Survival; Humans; Lithium Chloride; Motor Activity; Neurons; Oxidopamine; Parkinson Disease, Secondary; Rats; Rats, Wistar; Stem Cell Transplantation; Stem Cells; Substantia Nigra; Teratocarcinoma; Transplantation, Heterologous; Tyrosine 3-Monooxygenase | 2000 |
Facilitation of seizures in limbic epileptic rats by complex 1 microTesla magnetic fields.
On three separate sessions 24 male rats with histories of limbic epilepsy were exposed to 10 temporal configurations for 5 min. each of one of two patterns of magnetic fields. Their intensities averaged about 1 microTesla (microT). The numbers of Level 5 (Racine) seizures, inferred by the rat's rearing, rapid forelimb clonus, and falling, were statistically more frequent for the frequency-modulated (Thomas) pattern when its pixel duration and interstimulus presentation were 3 msec. The effectiveness of this temporal configuration was replicated in a second within-subjects experiment (n = 9) that directly compared the numbers of seizures during exposures to each of the two patterns and to a sham-field. These results suggest that brains with sensitive limbic systems might respond to weak magnetic fields, generated from multiple overlapping fields from communication and computer systems whose temporal derivatives emerge as complex sequences with pixel durations within the millisecond range. Topics: Animals; Disease Models, Animal; Electromagnetic Fields; Limbic System; Lithium Chloride; Male; Pilocarpine; Rats; Rats, Wistar; Seizures | 1999 |
Epi-inositol and inositol depletion: two new treatment approaches in affective disorder.
Inositol is a simple polyol precursor in a second messenger system important in brain myo-insitol, the natural isomer, which has been found to be therapeutically effective in depression, panic disorder, and obsessive-compulsive disorder in double-blind controlled trials. Recently, epi-inositol, an unnatural stereoisomer of myo-inositol, was found to have effects similar to those of myo-inositol to reverse lithium-pilocarpine seizures. We measured the behavior of rats in an elevated plus maze model of anxiety after chronic treatment of 11 daily intraperitoneal injections of epi-inositol, myo-inositol, or control solution. Epi-inositol reduced anxiety levels of rats compared with controls, and its effect was stronger than that of myo- inositol. Lithium has been hypothesized to alleviate mania by reducing brain inositol levels. Inositol in brain derives from the second messenger cycle, from new synthesis, or from diet via transport across the blood brain barrier. Because the first two are inhibited by lithium, we propose that an inositol-free diet will augment lithium action in mania by enhancing restriction of inositol. Topics: Animals; Antimanic Agents; Blood-Brain Barrier; Brain Chemistry; Diet; Disease Models, Animal; Humans; Inositol; Lithium Chloride; Male; Mood Disorders; Rats; Rats, Sprague-Dawley | 1999 |
Partial characterization of the enhanced survival of female NZB/W mice treated with lithium chloride.
Previous investigations have indicated that initiation of LiCl treatment (4 mg/day) of female NZB/W mice at 10 weeks of age led to enhanced survival of 50% of the mice to > 11 months of age (Lithium, 3, 61-67, 1992). The present results indicate that this enhancement of survival is dose dependent in that 2 mg 7LiCl/day was less effective than 4 mg 7LiCl/day. Daily treatment of groups of mice with 2 or 4 mg LiCl per day starting at 8 weeks of age led to the survival of 40% and 70%, respectively, of the mice at 40 weeks of age, a time when only 10% of the untreated mice remained alive. Initiation of treatment with 2 mg 7LiCl/day after the disease process was evident (24 weeks of age) led to diminished effectiveness. Parallel experiments with mice treated with 4 mg 7LiCl/day revealed 60% long-term survivors in the early treatment groups and 33% in the delayed treatment groups. Cessation of treatment in both groups led to some additional deaths, but 20-27% of the mice remained alive at 60 weeks of age, even though animals had detectable levels of anti-ssDNA antibodies in their serum. Additional experiments with 2 and 4 mg 7LiCl/day in NZB/W mice pretreated with C. parvum-PER, a treatment previously shown to enhance survival (Int. J. Immunopharmac., 14, 35-41, 1992), indicated that the effect of the two modalities was not additive. The results presented indicate that treatment of NZB/W mice with LiCl leads to very effective prolongation of survival by unique mechanisms, possibly involving alteration of the effector phase of autoimmune damage to the kidney or the susceptibility of kidney elements to immune-mediated damage leading to renal failure. Topics: Animals; Disease Models, Animal; Dose-Response Relationship, Drug; Female; Kidney; Lithium Chloride; Lupus Erythematosus, Systemic; Mice; Mice, Inbred NZB; Propionibacterium acnes; Survival Rate; Time Factors | 1994 |
Catalase, superoxide dismutase and glutathione peroxidase activity in neutrophils of sham-operated and olfactory-bulbectomised rats following chronic treatment with desipramine and lithium chloride.
In the olfactory-bulbectomised rat model of depression, neutrophil phagocytosis was significantly decreased and phagocytosis started later in comparison to sham-operated animals. Both desipramine and lithium chloride treatment significantly reversed the depressed neutrophil phagocytosis and shortened the time to commencement of phagocytosis in drug-treated bulbectomised rats. The catalase and glutathione peroxidase (GSH-PX) activities in bulbectomised rats were decreased, while superoxide dismutase (SOD) was significantly increased. Chronic desipramine and lithium chloride treatment slightly improved catalase activity in the bulbectomised rats. Desipramine significantly reversed the reduction in activity of GSH-PX, but failed to reverse the increased activity of SOD. In contrast, lithium chloride significantly reversed SOD activity to normal values, without affecting GSH-PX activity in the bulbectomised rats. Topics: Animals; Depressive Disorder; Desipramine; Disease Models, Animal; Glutathione Peroxidase; Lithium Chloride; Male; Neutrophils; Olfactory Bulb; Phagocytosis; Rats; Rats, Sprague-Dawley; Superoxide Dismutase | 1994 |
Protection of mice and swine against infection with Actinobacillus pleuropneumoniae by vaccination.
CaCl2 and LiCl cell extracts and a crude hemolysin preparation were isolated from Actinobacillus pleuropneumoniae serotype 1 strain 4074 and tested for protection against A. pleuropneumoniae serotype 1 and 5 in mice. The LiCl cell extract adsorbed on AlPO4 and the crude hemolysin preparation adsorbed on Al(OH)3 showed a highly significant protection (P < 0.01) against both serotypes. Different vaccine preparations were used to immunize pigs by intra-muscular injection at days 0 and 14; the pigs were then challenged at day 21 by intra-tracheal inoculation of 1 x 10(8) colony forming units (CFU) of a serotype 1 strain 4074. A vaccine which combined the LiCl extract and the crude hemolysin preparation adsorbed on Al(OH)3 gave the best protection with no mortality and no sign of morbidity in the vaccinated pigs. In the other experimental groups which included a group immunized with a commercial bacterin, mortality, respiratory disease and extensive pulmonary lesions were noted. This mixture shows good potential as a vaccine against pleuropneumonia in pigs. Topics: Actinobacillus Infections; Actinobacillus pleuropneumoniae; Animals; Bacterial Proteins; Bacterial Vaccines; Calcium Chloride; Disease Models, Animal; Hemolysin Proteins; Lithium Chloride; Male; Mice; Swine; Swine Diseases; Vaccination; Virulence | 1994 |
Effects of lithium on an amphetamine animal model of bipolar disorder.
1. This study examines the effects of chronic lithium administration on changes induced by amphetamine administration and withdrawal on open field locomotor activity of rats, and considered as an animal model of behaviors displayed in bipolar disorders. 2. For 21 days, rats were administered either single daily intraperitoneal injections (IP) of 0.9% saline, 0.15 mEq/kg, or 1.5 mEq/kg lithium chloride (LiCl). From day 7 to day 16, half of the animals in each group consisting of 12 rats were administered twice daily IP injections of either 1.5 mg/kg d-amphetamine or 0.9% saline. From day 17 to 21, d-amphetamine was withdrawn. 3. Neither dose of LiCl significantly altered the increases in activity levels produced by amphetamine. The withdrawal of amphetamine lead to an immediate return to baseline activity levels which neither dose of LiCl significantly affected. 4. The absence of interactive effects suggests that the influence of lithium and amphetamine on activity are mediated by different neurotransmitter systems. Topics: Animals; Bipolar Disorder; Chlorides; Dextroamphetamine; Disease Models, Animal; Lithium; Lithium Chloride; Male; Motor Activity; Rats; Rats, Inbred Strains; Reference Values; Substance Withdrawal Syndrome | 1990 |
Lithium chloride: protective and antisecretory properties in rats.
Lithium chloride was evaluated as a potential protective agent against ethanol-induced hemorrhagic gastritis in rats. Rats received lithium chloride intragastrically (30, 60, or 90 mg/kg i.g.) or subcutaneously (3, 5, 10, 15, 20, 30, 60, or 90 mg/kg s.c.), or a placebo (H2O i.g. or 0.9% NaCl s.c.). Ninety minutes later 1 cm3 of 95% ethanol was administered intragastrically. After 30 min, the rats were killed and their stomachs were removed and visually scored for gross hemorrhagic gastritis. Lithium chloride at all doses less than 3 mg/kg significantly improved hemorrhagic gastritis when compared with the placebo. Moreover, rats treated with lithium chloride intragastrically had significantly less hemorrhagic gastritis than those treated subcutaneously even though serum lithium levels were similar. To determine if lithium's protective properties related to acid inhibition, pylorus-ligated and gastric fistula rats were studied. The median effective dose for lithium chloride was 20-30 mg/kg and the nonantisecretory dose was 3 mg/kg. No difference in hemorrhagic gastritis was noted between controls and animals receiving the nonantisecretory dose. However, at higher doses (LiCl 30, 60, and 90 mg/kg), lithium's protective properties persisted in spite of adding 150 mM HCl to the intragastrically administered ethanol (p less than 0.001). To determine further if lithium chloride stimulated endogenous prostaglandins, indomethacin, a prostaglandin inhibitor, was administered. Indomethacin did not alter lithium chloride's protective properties. In fact, when compared with exogenously administered 16,16-dimethyl prostaglandin E2 (5 and 500 micrograms/kg), high-dose LiCl (30, 60, or 90 mg/kg) resulted in significantly more protection against ethanol-induced injury (p less than 0.001). In contrast, when both nonantisecretory doses were compared, 16,16-dimethyl prostaglandin E2 (5 micrograms/kg) gave significantly better protection than LiCl (3 mg/kg). These data indicate that LiCl is a potent gastric antisecretory and protective agent. The protective properties of LiCl appear to be related to acid inhibition and be independent of endogenous prostaglandins, although other protective mechanisms may be present at higher LiCl doses. Additionally, this study indicates that LiCl may have clinical application in protecting the gastric mucosa against hemorrhagic gastritis. Topics: Animals; Chlorides; Dinoprostone; Disease Models, Animal; Drug Evaluation; Ethanol; Gastric Acid; Gastric Mucosa; Gastritis; Gastrointestinal Hemorrhage; Indomethacin; Lithium; Lithium Chloride; Prostaglandins E; Rats; Rats, Inbred Strains | 1984 |
[Influence of lithium hydroxybutyrate on the electroencephalographic effects of fenamin].
Lithium hydroxybutyrate (10 mg/kg) prevents the amphetamine-induced EEG arousal and amplitude frequency alterations in the motor and visual cortex, posterior hypothalamus, midbrain reticular formation, and caudate nucleus but potentiates the action of the psychostimulant on the EEG of the hippocamp and amygdala. The response to the light flickering rhythm in the visual cortex remains within initial upon concurrent administration of both the drugs. Topics: Amphetamine; Animals; Bipolar Disorder; Cerebral Cortex; Chlorides; Disease Models, Animal; Drug Interactions; Electroencephalography; Humans; Hydroxybutyrates; Lithium; Lithium Chloride; Organometallic Compounds; Rabbits; Schizophrenia | 1982 |
[Urinary-blood delta PCO2 in renal tubular acidosis (author's transl)].
A state of renal tubular acidosis has been produced in rats by the administration of sodium maleate or acetazolamide (proximal tubular acidosis) and of lithium chloride of amiloride (distal tubular acidosis). During progressive alkaline diuresis, delta PCO2 (urine minus blood PCO2) increases significantly in rats presenting proximal tubular acidosis. Delta PCO2 is significantly depressed in rats presenting distal tubular acidosis. In well defined conditions of bicarbonate or phosphate excretion, delta PCO2 is a valuable index of distal ion secretion. Topics: Acetazolamide; Acidosis, Renal Tubular; Amiloride; Animals; Carbon Dioxide; Chlorides; Disease Models, Animal; Lithium; Lithium Chloride; Maleates; Partial Pressure; Rats | 1980 |