Maternal separation in neonatal rats elicits activation of the hypothalamic-pituitary-adrenocortical axis: a putative role for corticotropin-releasing factor.

Published

Journal Article

Stress elicits activation of the hypothalamic-pituitary-adrenocortical (HPA) axis. Hypothalamic neurohormones, including corticotropin-releasing factor (CRF), control and promote ACTH secretion and subsequent glucocorticoid synthesis and release. The neonatal rat has been shown to be relatively hyporesponsive to certain stressors, generating a blunted or unmeasurable hormonal response. In this study, the endocrine response of 10- and 18-day-old Sprague-Dawley rat pups to maternal separation, a naturalistic stressor, was examined. Ten-day pups subjected to maternal separation exhibited a significant reduction in median eminence CRF concentration at 24 h, with no change in pituitary CRF receptor number; in 18-day pups there was no significant change in median eminence CRF concentration by 24 h, but there was a decrease in CRF receptor binding. In adult rats subjected to stressors, an acute decrease in CRF concentration in the median eminence occurs, followed by CRF receptor downregulation with sustained stress. The results observed in the 18-day pups vs. the 10-day pups likely reflects a maturation of the HPA axis response to "stressors."

Full Text

Duke Authors

Cited Authors

  • Pihoker, C; Owens, MJ; Kuhn, CM; Schanberg, SM; Nemeroff, CB

Published Date

  • 1993

Published In

Volume / Issue

  • 18 / 7

Start / End Page

  • 485 - 493

PubMed ID

  • 8265736

Pubmed Central ID

  • 8265736

International Standard Serial Number (ISSN)

  • 0306-4530

Digital Object Identifier (DOI)

  • 10.1016/0306-4530(93)90042-j

Language

  • eng

Conference Location

  • England