Neural control of rhythmic buccal motor activity in molluscs

Abstract

Neural control mechanisms of the buccal rhythmic motor activity (RMA) in gastropod molluscs have been summarized. It is shown that the central pattern generator network underlying feeding movement shares important common features among different species, although various modifications have been made in each species. It is also demonstrated that several neurons in the central nervous system having regulatory action on the buccal RMA are homologous among species. Action of neurotransmitters or neuromodulators involved in the regulation of the buccal RMA has been surveyed. It is characteristic that several homologous neurons contain the same substances but their effects on RMA are not always the same but rather contradictory among different species and also in different states of the preparation even from the same species. Finally, the importance of bioactive peptides on the buccal RMA is stressed.