title: The neuropeptide NLP-22 regulates a sleep-like state in Caenorhabditis elegans.
abstract: Neuropeptides have central roles in the regulation of homoeostatic behaviours such as sleep and feeding. Caenorhabditis elegans displays sleep-like quiescence of locomotion and feeding during a larval transition stage called lethargus and feeds during active larval and adult stages. Here we show that the neuropeptide NLP-22 is a regulator of Caenorhabditis elegans sleep-like quiescence observed during lethargus. nlp-22 shows cyclical mRNA expression in synchrony with lethargus; it is regulated by LIN-42, an orthologue of the core circadian protein PERIOD; and it is expressed solely in the two RIA interneurons. nlp-22 and the RIA interneurons are required for normal lethargus quiescence, and forced expression of nlp-22 during active stages causes anachronistic locomotion and feeding quiescence. Optogenetic stimulation of the RIA interneurons has a movement-promoting effect, demonstrating functional complexity in a single-neuron type. Our work defines a quiescence-regulating role for NLP-22 and expands our knowledge of the neural circuitry controlling Caenorhabditis elegans behavioural quiescence.
authors.affiliation: Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
authors.forename: M D
authors.initials: MD
authors.lastname: Nelson
authors.forename: N F
authors.initials: NF
authors.lastname: Trojanowski
authors.forename: J B
authors.initials: JB
authors.lastname: George-Raizen
authors.forename: C J
authors.initials: CJ
authors.lastname: Smith
authors.forename: C-C
authors.initials: CC
authors.lastname: Yu
authors.forename: C
authors.initials: C
authors.lastname: Fang-Yen
authors.forename: D M
authors.initials: DM
authors.lastname: Raizen
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism*; D005247:Feeding Behavior; D007395:Interneurons / Q000378:metabolism; D007814:Larva / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D008124:Locomotion; D009479:Neuropeptides / Q000235:genetics / Q000378:metabolism*; D012890:Sleep; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D029742:Caenorhabditis elegans Proteins; C400538:LIN-42 protein, C elegans; C000589814:NLP-22 protein, C elegans; D009479:Neuropeptides; D014157:Transcription Factors