Circadian rhythms and autonomic function

Abstract

the mammalian circadian system is deeply interrelated with the autonomic nervous system.The two main output channels for the circadian clock are through humoral release or Sympathetic/parasympathetic relay stations that convey temporal information throughout the body. The SCN sends neural projections to other hypothalamic nuclei and from there to the brainstem or spinal cord autonomic centers that control physiological activity. In addition, neurovegetative mechanisms exhibit a double modulation by the circadian system (and, in turn, are synchronized to environmental synchronizers) and by arousal/sleep-related mechanisms in a homeostaticlike process.In this sense, autonomic regulation should not only be regarded as a spatial/functional control of physiology and behavior but also in terms of a strong temporal modulation that helps the body to adequately devote resources and energy throughout the day.