Pharmacological analysis of locomotion and heart contraction during the development of Helisoma (Mollusca: Gastropoda). Short communication.

Abstract

We investigated involvement of different 5-HT receptors in regulation of ciliary rotation, gliding locomotion and heartbeat of Helisoma embryo at pre- and post-metamorphic stages. Pharmacological analysis suggested that activation of 5-HT1 receptor enhance ciliary rotation but do not affect gliding locomotion. Activation of 5-HT4 receptor depresses both types of locomotion. Before metamorphosis heart contraction is depressed by activation of 5-HT4 and enhanced by activation of 5-HT7 receptor. However, the heart became insensitive to all agonists by hatching. We hypothesized that alterations in affinity or expression of particular 5-HT receptors can underlie the well-coordinated character of serotonin-dependent larval behavior.