Early, postnatal experience alters hypothalamic corticotropin-releasing factor (CRF) mRNA, median eminence CRF content and stress-induced release in adult rats

Brain Res Mol Brain Res. 1993 May;18(3):195-200. doi: 10.1016/0169-328x(93)90189-v.


Rat pups 2-14 days of age were exposed daily to handling (15 min of separation from mother and home cage), maternal separation (MS; 180 min of comparable separation), or were left entirely undisturbed (non-handled; NH). As adults, MS rats showed increased hypothalamic corticotropin-releasing factor (CRF) mRNA levels compared with NH rats, while CRF mRNA levels in H rats were significantly lower than either MS or NH animals. Hypothalamic CRF content under basal conditions followed exactly the same pattern. A 20-min period of restraint stress produced significant CRF depletion in all groups, although the percentage of depletion was significantly lower in H animals compared with either MS or NH animals. Restraint stress produced significantly higher increases in plasma corticosterone in MS and NH animals than in H animals. These data reflect the importance of early environmental factors in regulating the development of the hypothalamic CRF system and the responsiveness of the hypothalamic-pituitary-adrenal axis to stress.

Publication types

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

MeSH terms

  • Actins / genetics
  • Aging / physiology*
  • Animals
  • Animals, Newborn
  • Blotting, Northern
  • Corticosterone / blood
  • Corticotropin-Releasing Hormone / genetics*
  • Corticotropin-Releasing Hormone / metabolism*
  • Female
  • Handling, Psychological
  • Hypothalamus / growth & development
  • Hypothalamus / physiology*
  • Maternal Behavior
  • Median Eminence / growth & development
  • Median Eminence / metabolism*
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism*
  • Rats
  • Reference Values
  • Restraint, Physical
  • Social Isolation
  • Stress, Psychological / physiopathology*


  • Actins
  • RNA, Messenger
  • Corticotropin-Releasing Hormone
  • Corticosterone