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

https://doi.org/10.1016/0169-328X(93)90189-VGet rights and content

Abstract

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.

References (31)

  • J.L. Hess et al.

    Modification of the corticosterone response curve as a function of handling in infancy

    Physiol. Behav.

    (1969)
  • T. Iamki et al.

    Widespread expression of corticotropin-releasing factor messenger RNA and immunoreactivity in the rat olfactory bulb

    Brain Res.

    (1989)
  • H. Jingami et al.

    Effects of adrenalectomy and dexamethasone administration on the level of prepro-corticotropin-releasing factor mRNA in the hypothalamus and adrenocorticotropin/B-lipotropin precursor mRNA in the pituitary in rats

    Endocrinology

    (1985)
  • L.C. Krey et al.

    Surgical disconnections of the medial basal hypothalamus and pituitary function in the rhesus monkey. II. GH and cortisol secretion

    Endocrinology

    (1975)
  • C.M. Kuhn et al.

    Endocrine responses to mother-infant separation in developing rats

    Dev. Psychobiol.

    (1990)
  • Cited by (0)

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