CORTICOTROPIN-RELEASING HORMONE INVOLVEMENT IN STRESSOR-INDUCED ALTERATIONS IN SLEEP AND IN THE REGULATION OF WAKING

Sleep responds to a variety of stressors, but the precise mechanisms w hereby these alterations occur are not known. Ample evidence, however, testifies to corticotropin-releasing hormone (CRH) being uniquely sit uated to contribute to stresser-induced alterations in sleep. Behavior al responses to most stressors include periods of increased arousal an d waking, regardless of whether the stressor is psychological in natur e or results in physical insult. Furthermore, a large body of evidence suggests that CRH may also contribute to the regulation and maintenan ce of physiological waking. In this paper we hypothesize that CRH medi ates waking, particularly after periods of exposure to acute stressors . The complex interactions of multiple systems determine the behaviora l response to a particular stressor. As such, many factors determine t he time course and duration of response, including stresser type, and the status of a particular system at the time of stresser presentation . We briefly review data indicating that CRH mediates physiological an d behavioral responses to stressors, and present new data supporting t he hypothesis that CRH may also be involved in the physiological regul ation of waking.