[Serotonin-induced changes in the responses of electrically stimulated neuronal membrane of the mollusk].

Serotonin (5-HT) added to washing solution has been studied for its effect on plastic properties of electrically excitable membranes of the parietal ganglion and identified PPa2 neurons in the isolated nerve system of snails. It is shown that neurons habituated to intracellular stimulation are able to restore action potential generation in the presence of 5-HT. Contrary, neurons possessing endogenous rhythmic activity (PPa2) generate train activity on the background of appearance of the membrane potential slow waves under the influence of 5-HT. A comparative analysis of 5-HT and chemicals with the known effect on activity of Ca and Ca-dependent K-channels (quinine, CoCl2, CdCl2) has demonstrated diversity of mechanisms underlying the 5-HT-ergic regulation of plasticity of the neuronal electrically excitable membrane. This difference stems from the processes of activation and blockade of Ca-dependent channels.