cholecystokinin and Nerve-Degeneration

Topics: Animals; Axonal Transport; Axons; Capsaicin; Cholecystokinin; Edema; Fatty Acids, Unsaturated; Ganglia, Spinal; Nerve Degeneration; Nerve Fibers; Neurons, Afferent; Pain; Rats; Reflex; Sensation; Substance P

Spinocerebellar ataxias (SCAs) are a group of genetic diseases characterized by progressive ataxia and neurodegeneration, often in cerebellar Purkinje neurons. A SCA1 mouse model, Pcp2-ATXN1[30Q]D776, has severe ataxia in absence of progressive Purkinje neuron degeneration and death. Previous RNA-seq analyses identify cerebellar upregulation of the peptide hormone cholecystokinin (Cck) in Pcp2-ATXN1[30Q]D776 mice. Importantly, absence of Cck1 receptor (Cck1R) in Pcp2-ATXN1[30Q]D776 mice confers a progressive disease with Purkinje neuron death. Administration of a Cck1R agonist, A71623, to Pcp2-ATXN1[30Q]D776;Cck

Topics: Animals; Ataxin-1; Atrophy; Behavior, Animal; Calbindins; Chemokines, CC; Cholecystokinin; Disease Models, Animal; Female; Genetic Predisposition to Disease; Guanine Nucleotide Exchange Factors; Male; Mechanistic Target of Rapamycin Complex 1; Mice, Inbred C57BL; Mice, Knockout; Motor Activity; Nerve Degeneration; Neuropeptides; Purkinje Cells; Signal Transduction; Spinocerebellar Ataxias; Tetragastrin

Neuropeptide-containing hippocampal interneurons and dentate granule cell inhibition were investigated at different periods following electrical stimulation-induced, self-sustaining status epilepticus (SE) in rats. Immunohistochemistry for somatostatin (SOM), neuropeptide Y (NPY), parvalbumin (PV), cholecystokinin (CCK), and Fluoro-Jade B was performed on sections from hippocampus contralateral to the stimulated side and studied by confocal laser scanning microscopy. Compared to paired age-matched control animals, there were fewer SOM and NPY-immunoreactive (IR) interneurons in the hilus of the dentate gyrus in animals with epilepsy (40-60 days after SE), and 1, 3, and 7 days following SE. In the hilus of animals that had recently undergone SE, some SOM-IR and NPY-IR interneurons also stained for Fluoro-Jade B. Furthermore, there was electron microscopic evidence of the degeneration of SOM-IR interneurons following SE. In contrast, the number of CCK and PV-IR basket cells in epileptic animals was similar to that in controls, although it was transiently diminished following SE; there was no evidence of degeneration of CCK or PV-IR interneurons. Patch-clamp recordings revealed a diminished frequency of inhibitory postsynaptic currents in dentate granule cells (DGCs) recorded from epileptic animals and animals that had recently undergone SE compared with controls. These results confirm the selective vulnerability of a particular subset of dentate hilar interneurons after prolonged SE. This loss may contribute to the reduced GABAergic synaptic inhibition of granule cells in epileptic animals.

Topics: Animals; Cholecystokinin; Dentate Gyrus; Electric Stimulation; Epilepsy, Temporal Lobe; Fluorescent Dyes; Inhibitory Postsynaptic Potentials; Interneurons; Male; Matched-Pair Analysis; Nerve Degeneration; Neuropeptide Y; Parvalbumins; Patch-Clamp Techniques; Rats; Rats, Sprague-Dawley; Somatostatin; Synaptic Transmission

Niemann-Pick disease type C (NP-C) is a progressive neurological disorder of lipid metabolism. The Balb/C npc1 mutant strain is a genetically authentic murine model of NPC, which reproduce the clinical and histologic features of human NP-C. In the present study, we show that cholecystokinin (CCK)-immunoreactive fibers in the thalamic VPL nuclei, which are densely distributed in controls, degenerate in NPC mice. This degeneration is associated with the appearance of CCK-immunoreactive axonal spheroids containing characteristic intracellular inclusions of NP-C. These observations provide supportive evidence of the occurrence of dying-back axonopathy of neurons in the dorsal column nuclei in this mouse model.

Topics: Afferent Pathways; Animals; Axons; Cholecystokinin; Disease Models, Animal; Immunohistochemistry; Intracellular Signaling Peptides and Proteins; Mice; Mice, Inbred BALB C; Mice, Mutant Strains; Microscopy, Immunoelectron; Nerve Degeneration; Neurons; Niemann-Pick C1 Protein; Niemann-Pick Diseases; Proteins; Ventral Thalamic Nuclei

Retrograde labeling of duodenum-sphincter of Oddi (SO) preparations in vitro with the carbocyanine dye DiI revealed that duodenal neurons project to the SO. The duodenum-SO-projecting neurons were immunoreactive (IR) for choline acetyltransferase but not nitric oxide synthase or calretinin, indicating that this is a cholinergic projection and that this pathway is distinct from the circuitry involved in the ascending limb of the peristaltic reflex. Approximately 20% of the duodenum-SO projection neurons were IR for calbindin. Calbindin-IR nerves within SO ganglia degenerated when the SO was maintained in organ culture alone, but persisted when the SO was cultured with the duodenum intact. Therefore, SO ganglia are a target of the calbindin-positive duodenum-SO projection. Because calbindin is a marker of intrinsic sensory neurons that have processes that pass to the mucosa, these neurons are in position to detect the release of a compound from the mucosa and signal its release to SO ganglia. When applied to retrogradely labeled neurons, cholecystokinin (CCK) elicited a prolonged depolarization, indicating that duodenum-SO-projecting neurons could be capable of detecting CCK released from the mucosa. It is proposed that the role of the intrinsic sensory neurons that project to the SO may be to signal the postprandial release of CCK, thus providing an instruction to decrease SO resistance and facilitate the flow of bile into the duodenum.

Topics: Animals; Calbindin 2; Calbindins; Cells, Cultured; Cholecystokinin; Choline O-Acetyltransferase; Cholinergic Fibers; Duodenum; Efferent Pathways; Electrophysiology; Enteric Nervous System; Female; Guinea Pigs; Male; Membrane Potentials; Microelectrodes; Nerve Degeneration; Nerve Tissue Proteins; Neurons, Afferent; Nitric Oxide Synthase; S100 Calcium Binding Protein G; Sphincter of Oddi

Sprague-Dawley rats develop progressive motor dysfunctions during the third year of life. We use this as a model to examine possible neuronal mechanism(s) that may cause motor impairments occuring during aging. In this study we have used indirect immunofluorescence histochemistry (IF) and in situ hybridization histochemistry (ISH) to study quantitatively and qualitatively the staining pattern and mRNA expression of calcitonin gene-related peptide (alpha-CGRP), growth-associated protein 43 (GAP-43), and acidic fibroblast growth factor (aFGF) in spinal lumbar motoneurons of young adult (2-3 months) and aged (30 months) Sprague-Dawley rats. In addition, mRNAs encoding choline acetyltransferase (ChAT), beta-CGRP, and cholecystokinin (CCK) were analyzed. All aged rats used in this study disclosed symptoms of hindlimb incapacity, ranging from mild weight-bearing insufficiency to paralysis of the hind limbs. The symptoms were confined to the musculature of the hindlimb and hip regions. Only a small number (approximately 15%) of the large motoneurons that innervate the hindlimb muscles were lost in those aged rats that had clinical symptoms of hindlimb motor incapacities. The remaining motoneurons expressed ChAT mRNA at levels similar to those of young adult rats. The vast majority of these motoneurons showed increased mRNA levels for alpha-CGRP and GAP-43. Aged motoneurons contained more CGRP like immunoreactivity (LI), but the number of immunoreactive neurons was smaller than in adult rats. GAP-43-LI could be detected in motoneurons in aged, but not in adult, rats. GAP-43-LI was always colocalized with CGRP-LI in aged motoneurons. Studies of individual aged rats revealed that the increase of GAP-43 mRNA-positive cell bodies occurred in cases with the most severe clinical symptoms, whereas the increase in alpha-CGRP was even evident in rats with mild symptoms. No alterations in content of aFGF-LI or aFGF mRNA could be detected in the aged rat, and the content of CCK and beta-CGRP mRNAs was also normal. The usefulness of this rat model for studies of neuromuscular aging and possible functional roles for GAP-43 and CGRP in plastic and regenerative processes during aging are discussed.

Topics: Aging; Animals; Calcitonin Gene-Related Peptide; Cell Count; Cellular Senescence; Cholecystokinin; Choline O-Acetyltransferase; Fibroblast Growth Factor 1; GAP-43 Protein; Growth Substances; Hindlimb; Lumbosacral Region; Male; Membrane Glycoproteins; Motor Neurons; Nerve Degeneration; Nerve Tissue Proteins; Rats; Rats, Sprague-Dawley; RNA, Messenger; Spinal Cord

Somatostatin-, neuropeptide Y-, neurokinin B- and cholecystokinin-containing neurons were investigated in the rat hippocampus in two chronic models of temporal lobe epilepsy, i.e. 30 days after rapid kindling or electrically induced status epilepticus (post-status epilepticus). After rapid kindling, somatostatin immunoreactivity was strongly increased in interneurons and in the outer and middle molecular layer of the dentate gyrus. In four of six post-status epilepticus rats (status epilepticus I rats), somatostatin immunoreactivity was slightly increased in the dorsal but decreased in the ventral dentate gyrus and molecular layer. Somatostatin immunoreactivity decreased in neurons of the dorsal hilus in the two other post-status epilepticus rats investigated, while a complete loss was found in the respective ventral extension (status epilepticus-II rats). These changes were associated with a different extent of neurodegeneration as assessed by Nissl staining. Similarly, neuropeptide Y immunoreactivity was enhanced in neurons of the hilus and in the middle and outer molecular layer of the dentate gyrus in the dorsal hippocampus of rapidly kindled and status epilepticus-I rats. Neuropeptide Y and neurokinin B immunoreactivity was enhanced in the mossy fibers of all post-status epilepticus rats, but not in the rapidly kindled rats. In status epilepticus-II rats, neuropeptide Y-and neurokinin B-positive fibers were also detected in the infrapyramidal region of the stratum oriens of CA3 and in the inner molecular layer of the dentate gyrus in the dorsal and ventral hippocampus respectively, labeling presumably sprouted mossy fibers. Increased staining of neuropeptide Y and neurokinin B was found in the alveus after rapid kindling. Cholecystokinin immunoreactivity was markedly increased in the cerebral cortex, Ammon's horn and the molecular layer of the dentate gyrus in the ventral hippocampus of rapidly kindled and post-status epilepticus rats. The lasting changes in the immunoreactive pattern of various peptides in the hippocampus may reflect functional modifications in the corresponding peptide-containing neurons. These changes may be involved in chronic epileptogenesis, which evolves in response to limbic seizures.

Topics: Animals; Brain; Cholecystokinin; Chronic Disease; Epilepsy, Temporal Lobe; Immunohistochemistry; Male; Nerve Degeneration; Neurokinin B; Neuropeptide Y; Neuropeptides; Rats; Rats, Sprague-Dawley; Somatostatin; Tissue Distribution

The effect of deafferentation on the neuropeptides substance P (SP), calcitonin gene-related peptide (CGRP), somatostatin (SS), and cholecystokinin (CCK) in the lumbar dorsal horn of the adult rat was examined by the indirect immunohistochemical method. Deafferentation was induced by injecting the sciatic nerve of anesthetized rats with proteolytic enzymes (20 mg pronase), which cause selective death of the nerve's ganglion cells and degeneration of their terminal arborization in the spinal cord. The density of immunolabel of each peptide was determined by using a computerized densitometry analysis system in two animal groups, i.e., short-term (10-13 days after injection) and long-term (4-9 months). In both groups, the deafferentation produced a significant ipsilateral depletion of CGRP, SP, CCK, and SS immunoreactivity. This depletion was limited to the area occupied by the sciatic terminals in the dorsal horn. In the long-term group, the loss of CGRP and SP staining was significantly less than that in the short-term animals, thus indicating partial recovery. A similar, but not statistically significant, trend was observed for CCK and SS. The large decrease in CGRP and SP seen in short-term animals reflects the large contribution of the sciatic nerve to the lumbar dorsal horn. The partial recovery of peptides demonstrates the plasticity of the nervous system and may parallel sprouting of primary afferents from other nerves, such as the saphenous nerve, as we have demonstrated in previous studies.

Topics: Animals; Calcitonin Gene-Related Peptide; Cholecystokinin; Denervation; Female; Image Processing, Computer-Assisted; Immunohistochemistry; Injections; Nerve Degeneration; Neuronal Plasticity; Neurons, Afferent; Neuropeptides; Pronase; Rats; Rats, Sprague-Dawley; Sciatic Nerve; Somatostatin; Spinal Cord; Substance P

In order to study the control mechanism of cholecystokinin (CCK) contents of the rat brain mediated by pre-synaptic receptors in dopamine (DA) neurons, R(+) and S(-) compounds of 3-(3-hydroxyphenyl)-N-n-propylpiperidine (3-PPP), which are selective pre-synaptic dopaminergic agents, were administered in rats at low and high doses. CCK-8-like immunoreactivity (CCK-8 LI) was measured in the medial frontal cortex. In another experiment, a neurotoxin, N-methyl-D-aspartic acid (NMDA) was used to degenerate efferent CCK neurons and CCK interneurons of the medial frontal cortex, followed by an intraperitoneal administration of apomorphine hydrochloride (APO) to study the effect on CCK-8 LI via the pre-synaptic DA receptor. According to the results of these experiments, CCK-8 LI was increased in the medial frontal cortex in response to the stimulation of pre-synaptic DA receptor, suggesting a control of CCK-8 release, at least in part, by the pre-synaptic DA receptor.

Topics: Animals; Apomorphine; Behavior, Animal; Cholecystokinin; Dopamine; Dopamine Agents; In Vitro Techniques; Male; Microinjections; N-Methylaspartate; Nerve Degeneration; Neurons; Piperidines; Prefrontal Cortex; Rats; Rats, Wistar; Receptors, Dopamine

Lesion experiments were performed to investigate the origin of CCK-containing afferents of the striatum. All the subdivisions of the striatum that were investigated seem to receive CCK afferents from dorsolateral and lateral neocortical areas. However, destruction of these cortical areas alone did not reduce CCK-IRC in the striatum. Only after an additional parasagittal severance of the corpus callosum were significant decreases in CCK-IRC of all striatal subdivisions observed. Thus, CCK neurons in ipsilateral midline areas (such as the cingulate cortex) or, more likely, in contralateral cortical areas, seem to project to the striatum of one side. The CCK fibers seem to enter the striatum via the capsula externa, since a lesion of this structure has been shown to diminish the CCK-IRC in the striatum. In addition, the dorsomedial part of the head of the striatum may receive a projection of CCK fibers from the anterior cingulate area. A series of lesions which severed the afferents of structures caudal to the striatum, that is, the amygdaloid complex and the ventral tegmental area plus substantia nigra, did not reduce CCK-IRC in the striatum. Some of these lesions even significantly enhanced CCK-IRC in several subdivisions of the ipsilateral and contralateral striatum. Further studies will be necessary to cast some light on these caudal CCK afferents to the striatum, which are obviously extremely complex.

Topics: Afferent Pathways; Animals; Cerebral Cortex; Cholecystokinin; Corpus Callosum; Corpus Striatum; Male; Nerve Degeneration; Neurons; Rats; Rats, Inbred Strains

In order to identify the source and topography of cholecystokinin-containing fibers innervating the hypothalamic ventromedial nucleus (VMN), radioimmunoassay, immunocytochemistry, retrograde tracing of horseradish peroxidase and anterograde degeneration techniques were used. Cholecystokinin (CCK) disappeared almost totally from the VMN following a caudal diencephalic knife cut, which transected the medial fibers of the internal capsule, and the dorsolateral portion of the medial forebrain bundle at the level of the mammillary body. A number of cells in the ipsilateral dorsal parabrachial nucleus, furthermore, showed intense CCK-like immunoreactivity. The ascending CCK-containing fibers in the lateral part of the medial forebrain bundle reach the VMN from the lateral side. Neither the fibers of the stria terminalis, nor of the medial corticohypothalamic tract seem to carry any significant amount of CCK to the VMN.

Topics: Afferent Pathways; Amygdala; Animals; Brain Stem; Cholecystokinin; Horseradish Peroxidase; Medial Forebrain Bundle; Nerve Degeneration; Nerve Fibers; Pons; Radioimmunoassay; Rats; Ventromedial Hypothalamic Nucleus