Call it Worm Sleep

Trends Neurosci. 2016 Feb;39(2):54-62. doi: 10.1016/j.tins.2015.12.005. Epub 2015 Dec 30.


The nematode Caenorhabditis elegans stops feeding and moving during a larval transition stage called lethargus and following exposure to cellular stressors. These behaviors have been termed 'sleep-like states'. We argue that these behaviors should instead be called sleep. Sleep during lethargus is similar to sleep regulated by circadian timers in insects and mammals, and sleep in response to cellular stress is similar to sleep induced by sickness in other animals. Sleep in mammals and Drosophila shows molecular and functional conservation with C. elegans sleep. The simple neuroanatomy and powerful genetic tools of C. elegans have yielded insights into sleep regulation and hold great promise for future research into sleep regulation and function.

Keywords: Caenorhabditis elegans; cellular stress; development; evolution; quiescence; sleep.

Publication types

  • Research Support, N.I.H., Extramural
  • Review

MeSH terms

  • Animals
  • Caenorhabditis elegans / physiology*
  • Caenorhabditis elegans Proteins / physiology*
  • Humans
  • Locomotion / physiology
  • Nerve Net / physiology
  • Sleep / physiology*
  • Species Specificity


  • Caenorhabditis elegans Proteins