Grant: Travel Awards - Institute Community Support

The sex steroid milieu during the neonatal period in the rat exerts marked effects on the development of the hypothalamic-pituitary-adrenal (HPA) endocrine axis, including programming the process of stress habituation. Thus, previous findings in our lab indicate that blocking androgen receptors or preventing the conversion of testosterone to estrogen during the postnatal period impedes the normal decline in glucocorticoid steroid hormone responses seen during repeated stress. Using Western blot analysis of the glucocorticoid receptor protein in the hippocampus, we are currently examining in adult animals how postnatal alterations in androgen exposure in males and females are met by changes in glucocorticoid receptor signaling responses. As we intend on extending this analyses to other putative glucocorticoid negative feedback sites in the brain, we hope to reveal the sex- and region-specific nature by which the sex steroid hormones may come to permanently alter HPA axis function. Therefore, in this study we are interested in whether neonatal sex steroids have similar organizational effects on the HPA axes in female rats as we have previously seen in male rats. Secondly, if these changes in HPA output and habituation are due to neonatal sex steroid effects on the corticosteroid receptors.