Neurosteroids in the brain of handling-habituated and naive rats: effect of CO2 inhalation

Eur J Pharmacol. 1994 Aug 22;261(3):317-20. doi: 10.1016/0014-2999(94)90123-6.


In rats habituated to the manipulation that precedes killing (handling-habituated) the cerebral cortical concentrations of pregnenolone and progesterone were significantly lower (-57% and -69%, respectively) than in naive animals. An acute stress, induced by CO2 inhalation, elicited a marked increase in the concentrations of pregnenolone, progesterone and deoxycorticosterone in the brain cortex and hippocampus of handling-habituated rats. An accepted stress, such as foot shock, also enhanced the brain cortical levels of pregnenolone, progesterone and deoxycorticosterone in handling-habituated rats. These data show that the rat brain cortical and hippocampal steroid content is related to the 'emotional state' of the animal.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Inhalation
  • Animals
  • Brain Chemistry / physiology*
  • Carbon Dioxide / administration & dosage
  • Carbon Dioxide / pharmacology*
  • Cerebral Cortex / drug effects
  • Cerebral Cortex / metabolism
  • Desoxycorticosterone / metabolism
  • Electroshock
  • Handling, Psychological*
  • Hippocampus / drug effects
  • Hippocampus / metabolism
  • Male
  • Pregnenolone / metabolism
  • Progesterone / metabolism
  • Rats
  • Rats, Sprague-Dawley
  • Steroids / metabolism*


  • Steroids
  • Carbon Dioxide
  • Desoxycorticosterone
  • Progesterone
  • Pregnenolone