title: Inhibition of N- and P/Q-type Ca2+ channels by cannabinoid receptors in single cerebrocortical nerve terminals.
abstract: Since cannabinoid receptors inhibit excitatory synaptic transmission by reducing glutamate release, we have examined whether this might occur through the direct inhibition of presynaptic Ca2+ channels. In cerebrocortical nerve terminals, activation of cannabinoid receptors with WIN55,212-2 reduces the KCl-evoked release of glutamate. However, this inhibition is attenuated when N- and P/Q-type Ca2+ channels are blocked. Through Ca2+ imaging in single nerve terminals, we found that WIN55,212-2 reduced the influx of Ca2+ both in nerve terminals that contain N-type Ca2+ channels and those that contain P/Q-type Ca2+ channels. Thus, cannabinoid receptors modulate the two major Ca2+ channels coupled to glutamate release in the cerebral cortex.
authors.affiliation: Departamento de Bioquímica, Facultad de Veterinaria, Universidad Complutense, 28040-Madrid, Spain.
authors.forename: M C
authors.initials: MC
authors.lastname: Godino
authors.forename: M
authors.initials: M
authors.lastname: Torres
authors.forename: J
authors.initials: J
authors.lastname: Sánchez-Prieto
mesh_terms: D000818:Animals; D048588:Benzoxazines; D002118:Calcium / Q000378:metabolism; D015220:Calcium Channels / Q000502:physiology*; D002540:Cerebral Cortex / Q000187:drug effects* / Q000502:physiology; D017136:Ion Transport; D008297:Male; D009025:Morpholines / Q000494:pharmacology; D009281:Naphthalenes / Q000494:pharmacology; D009411:Nerve Endings / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D043882:Receptors, Cannabinoid / Q000502:physiology*
chemical_list: D048588:Benzoxazines; D015220:Calcium Channels; D009025:Morpholines; D009281:Naphthalenes; D043882:Receptors, Cannabinoid; C070417:(3R)-((2,3-dihydro-5-methyl-3-((4-morpholinyl)methyl)pyrrolo-(1,2,3-de)-1,4-benzoxazin-6-yl)(1-naphthalenyl))methanone; D002118:Calcium