Neuromuscular Systems in Molluscs

Some structural and related functional characteristics of molluscan muscle and some characteristics of the widely-studied sustained contraction, known as “catch” are considered.

Abstract

Molluscs have become increasingly popular in the study of central neural mechanisms. More recently, there have been attempts to relate activity in central neurons with behavior in animals of this phylum. The latter studies necessitate an understanding of the effectors of such behaviors. This requires not only information about the neuromuscular junction, but also an awareness of the capabilities of the muscles themselves. Therefore, we have discussed some structural and related functional characteristics of molluscan muscle. We suggest that invertebrate mucles might be compared on three scales: the amount of myofilament organization, the amount of vesicular specialization and organization, and the amount of paramyosin. We have considered some characteristics of the widely-studied sustained contraction, known as “catch.” Finally, we have discussed the neuromuscular junction—the types of junctions, the multiplicity of innervation, and some aspects of pharmacology. The results of such a study indicated many areas in which further research is essential before we can understand behavior in terms of activity in the central nervous system.