Orcokinin neuropeptides regulate sleep in <i>Caenorhabditis elegans</i>

Abstract

Orcokinin neuropeptides are conserved among ecdysozoans, but their functions are incompletely understood. Here, we report a role for orcokinin neuropeptides in the regulation of sleep in the nematode <i>Caenorhabditis elegans</i>. The <i>C. elegans</i> orcokinin peptides, which are encoded by the <i>nlp-14</i> and <i>nlp-15</i> genes, are necessary and sufficient for quiescent behaviors during developmentally timed sleep (DTS) as well as during stress-induced sleep (SIS). The five orcokinin neuropeptides encoded by <i>nlp-14</i> have distinct but overlapping functions in the regulation of movement and defecation quiescence during SIS. We suggest that orcokinins may regulate behavioral components of sleep-like states in nematodes and other ecdysozoans.