anandamide and Cognition-Disorders

Exogenous cannabinoids, such as delta9-tetrahydrocannabinol (THC), as well as the modulation of endogenous cannabinoids, affect cognitive function through the activation of cannabinoid receptors. Indeed, these compounds modulate a number of signalling pathways critically implicated in the deleterious effect of cannabinoids on learning and memory. Thus, the involvement of the mammalian target of rapamycin pathway and extracellular signal-regulated kinases, together with their consequent regulation of cellular processes such as protein translation, play a critical role in the amnesic-like effects of cannabinoids. In this study, we summarize the cellular and molecular mechanisms reported in the modulation of cognitive function by the endocannabinoid system.

Topics: Animals; Arachidonic Acids; Cannabinoid Receptor Agonists; Cognition; Cognition Disorders; Dronabinol; Endocannabinoids; Glycerides; Hippocampus; Humans; Memory; Neuronal Plasticity; Polyunsaturated Alkamides; Receptor, Cannabinoid, CB1; Synaptic Transmission; TOR Serine-Threonine Kinases

Endocannabinoids (ECs) are rapidly acting immune-modulatory lipid-signaling molecules that are important for adaptation to stressful and aversive situations.They are known to interact with glucocorticoids and other stress-responsive systems. Maladaptation to acute or chronic stress represents a major risk factor for the development of psychiatric disorders. In the present study, we administered stress doses of hydrocortisone ina prospective, randomized, placebo-controlled double blind study in patients undergoing cardiac surgery (CS) to examine the relationship between the use of glucocorticoids, plasma EC levels, and the occurrence of early postoperative cognitive dysfunction (delirium) and of later development of depression.. We determined plasma levels of the ECs anandamide and 2-arachidonoylglycerol (2-AG) in CS patients of the hydrocortisone (n=56) and the placebo group(n=55) preoperatively, at postoperative day (POD) 1, at intensive care unit discharge, and at 6 months after CS(n=68). Postoperative delirium was diagnosed according to Diagnostic and Statistical Manual of the American Psychiatric Association IVth Edition (DSM-IV) criteria, and depression was determined by validated questionnaires and a standardized psychological interview (Structured Clinical Interview for DSM-IV).. Stress doses of hydrocortisone did not affect plasma EC levels and the occurrence of delirium or depression. However, patients who developed deliriumon POD 1 had significantly lower preoperative 2-AG levels of the neuroprotective EC 2-AG (median values, 3.8 vs. 11.3ng/ml; p=0.03). Preoperative 2-AG concentrations were predictive of postoperative delirium (sensitivity=0.70;specificity=0.69; cutoff value=4.9 ng/ml; receiver operating characteristic curve area=0.70; 95 o/o confidence interval=0.54-0.85). Patients with depression at 6 months after CS (n=16) had significantly lower anandamide and 2-AG levels during the perioperative period.. A low perioperative EC response may indicate an increased risk for early cognitive dysfunction and long-term depression in patients after CS. Glucocorticoids do not seem to influence this relationship.

Topics: Aged; Arachidonic Acids; Cognition Disorders; Depression; Double-Blind Method; Endocannabinoids; Female; Follow-Up Studies; Glucocorticoids; Glycerides; Heart Diseases; Humans; Hydrocortisone; Luria-Nebraska Neuropsychological Battery; Male; Middle Aged; Outcome Assessment, Health Care; Polyunsaturated Alkamides; Postoperative Complications; Prospective Studies; Psychiatric Status Rating Scales; Psychometrics; Statistics, Nonparametric

The endocannabinoids and their attending cannabinoid (CB)(1) receptors have been implicated in the control of cognition, but their possible roles in dementias are still unclear. In the present study, we used liquid chromatography/mass spectrometry to conduct an endocannabinoid-targeted lipidomic analysis of postmortem brain samples from 38 Alzheimer's disease (AD) patients and 17 control subjects, matched for age and postmortem interval. The analysis revealed that midfrontal and temporal cortex tissue from AD patients contains, relative to control subjects, significantly lower levels of the endocannabinoid anandamide and its precursor 1-stearoyl, 2-docosahexaenoyl-sn-glycero-phosphoethanolamine-N-arachidonoyl (NArPE). No such difference was observed with the endocannabinoid 2-arachidonoyl-sn-glycerol or 15 additional lipid species. In AD patients, but not in control subjects, statistically detectable positive correlations were found between (1) anandamide content in midfrontal cortex and scores of the Kendrick's Digit Copy test (p = 0.004, r = 0.81; n = 10), which measures speed of information processing; and (2) anandamide content in temporal cortex and scores of the Boston Naming test (p = 0.027, r = 0.52; n = 18), which assesses language facility. Furthermore, anandamide and NArPE levels in midfrontal cortex of the study subjects inversely correlated with levels of the neurotoxic amyloid peptide, amyloid β-protein (Aβ)(42), while showing no association with Aβ(40) levels, amyloid plaque load or tau protein phosphorylation. Finally, high endogenous levels of Aβ(42) in Swedish mutant form of amyloid precursor protein (APP(SWE))/Neuro-2a cells directly reduced anandamide and NArPE concentrations in cells lysates. The results suggest that an Aβ(42)-dependent impairment in brain anandamide mobilization contributes to cognitive dysfunction in AD.

Topics: Aged; Alzheimer Disease; Amyloid beta-Peptides; Arachidonic Acids; Cadaver; Cerebral Cortex; Cognition Disorders; Endocannabinoids; Female; Humans; Lipid Metabolism; Male; Peptide Fragments; Polyunsaturated Alkamides; Tissue Distribution

Topics: Adaptation, Physiological; Adaptation, Psychological; Arachidonic Acids; Chronic Disease; Cognition Disorders; Comorbidity; Diagnosis, Dual (Psychiatry); Endocannabinoids; Humans; Life Change Events; Marijuana Smoking; Polyunsaturated Alkamides; Receptors, Nicotinic; Schizophrenia; Schizophrenic Psychology; Self Medication; Stress, Psychological