title: Ca(2+)-assisted receptor-driven endocannabinoid release: mechanisms that associate presynaptic and postsynaptic activities.
abstract: Endogenous cannabinoids (endocannabinoids) serve as retrograde messengers at synapses in various regions of the brain. They are released from postsynaptic neurons and cause transient and long-lasting reduction of neurotransmitter release through activation of presynaptic cannabinoid receptors. Endocannabinoid release is induced either by increased postsynaptic Ca(2+) levels or by activation of G(q/11)-coupled receptors. When these two stimuli coincide, endocannabinoid release is markedly enhanced, which is attributed to the Ca(2+) dependency of phospholipase Cbeta (PLCbeta). This Ca(2+)-assisted receptor-driven endocannabinoid release is suggested to participate in various forms of synaptic plasticity, including short-term associative plasticity in the cerebellum and spike-timing-dependent long-term depression in the somatosensory cortex. In these forms of plasticity, PLCbeta seems to function as a coincident detector of presynaptic and postsynaptic activities.
authors.affiliation: Department of Neurophysiology, Graduate School of Medicine, Osaka University, Suita 565-0871, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Hashimotodani
authors.forename: Takako
authors.initials: T
authors.lastname: Ohno-Shosaku
authors.forename: Masanobu
authors.initials: M
authors.lastname: Kano
mesh_terms: D000818:Animals; D002118:Calcium / Q000502:physiology*; D063385:Cannabinoid Receptor Modulators / Q000378:metabolism*; D063388:Endocannabinoids; D008954:Models, Biological; D013569:Synapses / Q000378:metabolism*; D009435:Synaptic Transmission / Q000502:physiology*
chemical_list: D063385:Cannabinoid Receptor Modulators; D063388:Endocannabinoids; D002118:Calcium