piperidines and Perceptual-Disorders

Topics: Adult; Aggression; Anticonvulsants; Anxiety; Carbamazepine; Clinical Trials as Topic; Diazepam; Dibenzazepines; Epilepsy; Frustration; Hallucinations; Humans; Intellectual Disability; Middle Aged; Nitriles; Object Attachment; Perceptual Disorders; Phenothiazines; Piperidines; Psychiatric Status Rating Scales; Psychopathology; Schizophrenia; Thiazines; Tranquilizing Agents

Endocannabinoids (ECBs) depress transmitter release at sites throughout the brain. Here, we describe another form of ECB signaling that triggers a novel form of long-term potentiation (LTP) localized to the lateral perforant path (LPP) which conveys semantic information from cortex to hippocampus. Two cannabinoid CB1 receptor (CB1R) signaling cascades were identified in hippocampus. The first is pregnenolone sensitive, targets vesicular protein Munc18-1 and depresses transmitter release; this cascade is engaged by CB1Rs in Schaffer-Commissural afferents to CA1 but not in the LPP, and it does not contribute to LTP. The second cascade is pregnenolone insensitive and LPP specific; it entails co-operative CB1R/β1-integrin signaling to effect synaptic potentiation via stable enhancement of transmitter release. The latter cascade is engaged during LPP-dependent learning. These results link atypical ECB signaling to the encoding of a fundamental component of episodic memory and suggest a novel route whereby endogenous and exogenous cannabinoids affect cognition.

Topics: Animals; Cerebral Cortex; Endocannabinoids; Enzyme Inhibitors; GABA Agents; Hippocampus; Lipid Metabolism; Male; Memory; Mice; Mice, Inbred C57BL; Mice, Knockout; Munc18 Proteins; Neural Pathways; Neurons; Perceptual Disorders; Piperidines; Pyrazoles; Rats; Rats, Sprague-Dawley; Signal Transduction