This Article Full Text Full Text (PDF) All Versions of this Article: 149/7/3581    most recent Author Manuscript (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Copyright Permission Google Scholar Articles by Bingham, B. Articles by Viau, V. PubMed PubMed Citation Articles by Bingham, B. Articles by Viau, V.

Neonatal Gonadectomy and Adult Testosterone Replacement Suggest an Involvement of Limbic Arginine Vasopressin and Androgen Receptors in the Organization of the Hypothalamic-Pituitary-Adrenal Axis

Neuroscience Program, Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3

Address all correspondence and requests for reprints to: Victor Viau, Department of Cellular and Physiological Sciences, Life Sciences Centre, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, British Columbia, Canada V6T 1Z3. E-mail: viau{at}interchange.ubc.ca.

Testosterone exposure during critical periods of development exerts major organizing effects on the hypothalamic-pituitary-adrenal (HPA) axis. Here we examined how neonatal gonadectomy (GDX) with or without testosterone treatment during the first week of life alters the HPA response to adult testosterone replacement in 65-d-old male rats. As adults, neonatal GDX rats showed higher levels of plasma corticosterone and Fos activation in medial parvocellular part of the paraventricular nucleus of the hypothalamus under basal conditions and during 30 min of restraint exposure. These responses were normalized with testosterone treatment on postnatal d 1–5 but were not restored with adult testosterone replacement. As adults, neonatal GDX rats also showed a decrease in the number of androgen receptor and arginine vasopressin-positive cells in the bed nucleus of the stria terminalis and in the medial nucleus of the amygdala, and both of these responses were reversed with postnatal testosterone treatment. In stressed and unstressed animals, the number of androgen receptors and arginine vasopressin-expressing neurons in both of these nuclei correlated negatively with corticosterone concentrations in plasma and Fos levels in the paraventricular nucleus. Taken together, our findings suggest that testosterone exposure during the neonatal period primes the adult HPA response to testosterone by altering androgen receptor levels and function within afferent mediators of basal and stress-related input to the HPA axis.