Homeostasis in C. elegans sleep is characterized by two behaviorally and genetically distinct mechanisms

Elife. 2014 Dec 4;3:e04380. doi: 10.7554/eLife.04380.


Biological homeostasis invokes modulatory responses aimed at stabilizing internal conditions. Using tunable photo- and mechano-stimulation, we identified two distinct categories of homeostatic responses during the sleep-like state of Caenorhabditis elegans (lethargus). In the presence of weak or no stimuli, extended motion caused a subsequent extension of quiescence. The neuropeptide Y receptor homolog, NPR-1, and an inhibitory neuropeptide known to activate it, FLP-18, were required for this process. In the presence of strong stimuli, the correlations between motion and quiescence were disrupted for several minutes but homeostasis manifested as an overall elevation of the time spent in quiescence. This response to strong stimuli required the function of the DAF-16/FOXO transcription factor in neurons, but not that of NPR-1. Conversely, response to weak stimuli did not require the function of DAF-16/FOXO. These findings suggest that routine homeostatic stabilization of sleep may be distinct from homeostatic compensation following a strong disturbance.

Keywords: C. elegans; homeostasis; insulin; lethargus; neuropeptides; neuroscience; quiescence; sleep.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Behavior, Animal* / radiation effects
  • Caenorhabditis elegans / genetics*
  • Caenorhabditis elegans / physiology*
  • Caenorhabditis elegans / radiation effects
  • Caenorhabditis elegans Proteins / metabolism
  • Homeostasis* / radiation effects
  • Light
  • Locomotion / radiation effects
  • Neuropeptides / metabolism
  • Photic Stimulation
  • Physical Stimulation
  • Posture / physiology
  • Receptors, Neuropeptide Y / metabolism
  • Signal Transduction / radiation effects
  • Sleep / physiology*
  • Sleep / radiation effects


  • Caenorhabditis elegans Proteins
  • NPR-1 protein, C elegans
  • Neuropeptides
  • Receptors, Neuropeptide Y