The Roles of Neuropeptides in Caenorhabditis elegans Including their Importance in the Regulation of Feeding and Metabolism

C. elegans has 302 neurons (in the adult hermaphrodite) and this simple nervous system harbours over 250 neuropeptides. Neuropeptides are a class of signalling molecule implicated in key physiological roles and thus confer a surprising level of complexity to signalling in this nematode. Indeed, it is probable that most, if not all, sensory, motor and interneurons, in C. elegans synthesise and release at least one neuropeptide but that many neurons synthesise an array of neuropeptides. In this review neuropeptides and their receptors with specific roles in feeding, metabolism, reproduction and locomotion are discussed. It is noted that the majority of C. elegans neuropeptides do not yet have defined roles and their cognate receptors have not yet been identified. Future studies will serve to provide further fundamental insight into how neuropeptide signalling can underpin animal behaviour.