Water-avoidance stress-induced c-fos expression in the rat brain and stimulation of fecal output: role of corticotropin-releasing factor

Brain Res. 1994 Mar 28;641(1):21-8. doi: 10.1016/0006-8993(94)91810-4.


Immunohistochemical detection of the immediate-early gene c-fos was used to determine the pattern of neuronal activity in the rat brain after exposure to water-avoidance stress known to stimulate fecal output in rats. Avoidance to water for 1 h by standing on a small platform increases pellet output and induces numerous Fos-positive cells in the parvocellular part of the paraventricular nucleus of the hypothalamus (PVN), locus coeruleus (LC) and, to a lesser extent, in the bed nucleus of the stria terminalis, lateral septum, dorsal raphe nucleus and A5 and A1 noradrenergic neurons. The corticotropin-releasing factor (CRF) antagonist, alpha-helical CRF9-41 (50 micrograms i.c.v.) reduced water-avoidance stress-induced c-fos expression mainly in the PVN and the LC (44 and 60%, respectively) and decreased by 60% the stimulated fecal output. These data indicate that water-avoidance stress activates PVN and LC neurons through CRF pathways which contribute to the stimulation of colonic motor function.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Avoidance Learning / physiology*
  • Brain / metabolism*
  • Corticotropin-Releasing Hormone / antagonists & inhibitors
  • Corticotropin-Releasing Hormone / physiology*
  • Defecation / physiology*
  • Injections, Intraventricular
  • Male
  • Proto-Oncogene Proteins c-fos / biosynthesis*
  • Rats
  • Rats, Sprague-Dawley
  • Stress, Physiological / metabolism*
  • Water


  • Proto-Oncogene Proteins c-fos
  • Water
  • Corticotropin-Releasing Hormone