[Identification of serotonin receptors in several grape snail neurons].

Four types of unit responses to iontophoretical serotonin (5-hydroxytrytamine) application were obtained on the ventral surface of the visceral ganglion in the hibernating Helix pomatia. The responses differed in sign, duration, latent period, reaction to serotonin antagonists (d-tubocurarine, tryptamine, neostigmine). It seems that every type of unit response to serotonin is associated with a definite type of serotonin receptors. A scheme of serotonin receptor distribution in the studied neurons is presented.