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

Catherine Pihoker, Michael J. Owens, Cynthia M. Kuhn, Saul M. Schanberg, Charles Nemeroff

Research output: Contribution to journalArticle

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Abstract

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.".

Original languageEnglish
Pages (from-to)485-493
Number of pages9
JournalPsychoneuroendocrinology
Volume18
Issue number7
DOIs
StatePublished - Jan 1 1993
Externally publishedYes

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ASJC Scopus subject areas

  • Endocrinology
  • Endocrinology, Diabetes and Metabolism
  • Psychiatry and Mental health
  • Biological Psychiatry
  • Endocrine and Autonomic Systems
  • Psychology(all)

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