INFLUENCE OF THE DELTA-SLEEP-INDUCING PEPTIDE AND SEROTONIN ON THE NEURONS OF A SNAIL

The present paper describes the results concerning the influence of delta sleep-inducing peptide (DSIP) and serotonin (5-HT) on electrophysiological properties of the identified snail neurons. The experiments were performed on semi-intact preparations from Helix lucorum L. DSIP inhibited spontaneously active neurons and reduced responses of silent cells to depolarizing currents and tactile stimuli. DSIP effects were dose-dependent. 5-HT excited neurons in question. DSIP and 5-HT had the mutually opposite effects on the identified neurons. The results suggest that DSIP can directly affect the snail neurons not via serotoninergic system. Hyperpolarization effect of DSIP can be due to the enhancement of Cl conduction or to the changes in adenylatcyclase system activity. Alternatively DSIP can influence the process of synaptic transmission.