Circadian Neurobiology and the Physiologic Regulation of Sleep and Wakefulness

Neurol Clin. 2019 Aug;37(3):475-486. doi: 10.1016/j.ncl.2019.03.001. Epub 2019 May 7.


Endogenous central and peripheral circadian oscillators are key to organizing multiple aspects of mammalian physiology; this clock tracks the day-night cycle and governs behavioral and physiologic rhythmicity. Flexibility in the timing and duration of sleep and wakefulness, critical to the survival of species, is the result of a complex, dynamic interaction between 2 regulatory processes: the clock and a homeostatic drive that increases with wake duration and decreases during sleep. When circadian rhythmicity and sleep homeostasis are misaligned-as in shifted schedules, time zone transitions, aging, or disease-sleep, metabolic, and other disorders may ensue.

Keywords: Circadian rhythms; Homeostasis; Physiology; Sleep; Suprachiasmatic nucleus.

Publication types

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

MeSH terms

  • Animals
  • Circadian Rhythm / physiology*
  • Homeostasis / physiology
  • Humans
  • Sleep / physiology*
  • Wakefulness / physiology*