title: Opposite effects of nitric oxide on identified inhibitory and excitatory cholinergic synapses of Aplysia californica.
abstract: The effects of nitric oxide on evoked acetylcholine (ACh) release were studied at two identified cholinergic neuro-neuronal synapses of the nervous system of the mollusc Aplysia californica. The NO-donor, 3-morpholinosydnonimine (SIN-1), decreased the amplitude of evoked inhibitory postsynaptic currents (buccal ganglion) and potentiated that of evoked excitatory postsynaptic currents (abdominal ganglion). SIN-1 acted by modulating the number of ACh quanta released. 8Br-cGMP mimicked the effects of NO on ACh release in both types of synapses thus pointing to the involvement of a NO-sensitive guanylate cyclase. Presynaptic voltage-dependent Ca2+ and K+ (IA and late outward rectifier) currents were not modified by SIN-1 suggesting another final target for NO/cGMP. The labelling of a NO-synthase by immunostaining in several neurones as well as the modulation of ACh release by L-arginine indicate that an endogenous NO-synthase is involved in the modulation of synaptic efficacy in both buccal and abdominal ganglia.
authors.affiliation: Laboratoire de Neurobiologie Cellulaire et Moléculaire C.N.R.S., Gif-sur-Yvette, France.
authors.forename: J P
authors.initials: JP
authors.lastname: Mothet
authors.forename: P
authors.initials: P
authors.lastname: Fossier
authors.forename: A
authors.initials: A
authors.lastname: Schirar
authors.forename: L
authors.initials: L
authors.lastname: Tauc
authors.forename: G
authors.initials: G
authors.lastname: Baux
mesh_terms: D000109:Acetylcholine / Q000378:metabolism* / Q000494:pharmacology; D000200:Action Potentials; D000818:Animals; D001048:Aplysia; D001120:Arginine / Q000494:pharmacology; D015220:Calcium Channels / Q000187:drug effects; D018679:Cholinergic Agonists / Q000494:pharmacology; D018680:Cholinergic Antagonists / Q000494:pharmacology; D006152:Cyclic GMP / Q000031:analogs & derivatives / Q000494:pharmacology; D017952:Ganglia, Invertebrate / Q000187:drug effects / Q000378:metabolism; D005726:Ganglia, Parasympathetic / Q000187:drug effects* / Q000378:metabolism; D006162:Guanylate Cyclase / Q000378:metabolism; D008981:Molsidomine / Q000031:analogs & derivatives / Q000494:pharmacology; D009569:Nitric Oxide / Q000494:pharmacology*; D019001:Nitric Oxide Synthase / Q000378:metabolism; D015221:Potassium Channels / Q000187:drug effects; D013569:Synapses / Q000187:drug effects* / Q000378:metabolism; D009435:Synaptic Transmission / Q000187:drug effects*
chemical_list: D015220:Calcium Channels; D018679:Cholinergic Agonists; D018680:Cholinergic Antagonists; D015221:Potassium Channels; C016276:8-bromocyclic GMP; D009569:Nitric Oxide; C002385:linsidomine; D001120:Arginine; D008981:Molsidomine; D019001:Nitric Oxide Synthase; D006162:Guanylate Cyclase; D006152:Cyclic GMP; D000109:Acetylcholine