[Serotonin modulation of acetylcholine-induced currents in mollusk neurons as dependent on cyclic guanosine monophosphate].

It was found that a serotonin-induced decrease of the acetylcholine-induced chloride current in a group of right parietal ganglion neurons of the snail Helix pomatia was mimicked neither by dibutyryl cAMP nor by isobutyl methylxanthine. In contrast it was mimicked by the extracellular application of sodium nitroprusside as a guanylate cyclase activator, and by intracellular injection of cyclic guanosine monophosphate.