Activation of cortical interneurons during sleep: an anatomical link to homeostatic sleep regulation?

Trends Neurosci. 2011 Jan;34(1):10-9. doi: 10.1016/j.tins.2010.09.005. Epub 2010 Oct 26.


Although slow wave activity in the EEG has been linked to homeostatic sleep regulation, the neurobiological substrate of sleep homeostasis is not well understood. Whereas cortical neurons typically exhibit reduced discharge rates during slow wave sleep (SWS), a subpopulation of GABAergic interneurons, which express the enzyme neuronal nitric oxide synthase (nNOS), has recently been found to be activated during SWS. The extent of activation of these nNOS neurons is proportional to homeostatic sleep 'drive'. These cells are an exception among cortical interneurons in that they are projection neurons. We propose that cortical nNOS neurons are positioned to influence neuronal activity across widespread brain areas. They could thus provide a long-sought anatomical link for understanding homeostatic sleep regulation.

Publication types

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

MeSH terms

  • Animals
  • Cerebral Cortex / cytology*
  • Cerebral Cortex / physiology*
  • Electroencephalography
  • Homeostasis*
  • Humans
  • Interneurons / cytology
  • Interneurons / physiology*
  • Nitric Oxide / metabolism
  • Nitric Oxide Synthase Type I / metabolism
  • Sleep / physiology*
  • gamma-Aminobutyric Acid / metabolism


  • Nitric Oxide
  • gamma-Aminobutyric Acid
  • Nitric Oxide Synthase Type I