Neuroendocrine effects of peripubertal stress exposure in the female mouse

• Main Author: Laroche, Julie
• Language: ENG
• Published: ScholarWorks@UMass Amherst 2008
• Subjects: Neurology|Health|Anatomy & physiology
• Online Access: https://scholarworks.umass.edu/dissertations/AAI3315522

The peripubertal period is a period during which significant brain re-organization occurs, and during which changes in the neuroendocrine milieu normally lead to the onset of fertility. Shipping female mice during the peripubertal period causes a long-lasting behavioral defeminization of feminine sexual behavior. Because shipping is a stressor, it was suggested that peripubertal stress exposure might interfere with the regulation of feminine sexual behaviors in adult female mice. As a result, the goal of this research was to examine the effects of peripubertal stress exposure on neuroendocrine regulation of the hypothalamo-pituitary-gonadal (HPG) and the hypothalamo-pituitary-adrenal (HPA) axis. However, although peripubertally exposing female mice to shipment stress caused a significant decrease in sexual receptivity, peripubertal exposure to restraint stress, food deprivation, social stress and instability, or multiple stressors (heat, light, and restraint) did not decrease sexual receptivity during adulthood. Only exposure to a high dose of bacterial endotoxin during the peripubertal period duplicated the defeminizing effect of shipping during the peripubertal period on adult mouse feminine sexual behavior. Interestingly, significant long-term effects of peripubertal stress exposure were also observed in the regulation of the HPA axis, where exposure to peripubertal shipping and LPS led to blunted stress-induced corticosterone responses in adult female mice. Peripubertal exposure to shipping and LPS had long-lasting effects on steroid receptor expression in brain areas relevant to female reproduction. Nevertheless, peripubertal exposure to LPS did not interfere with the ability of estradiol to induce the release of LH. Moreover, although peripubertal exposure to shipping decreased masculine sexual behavior in male, but not female, mice, peripubertal exposure to LPS was without effect on masculine sexual behavior. These results suggest that exposure to some, but not all, peripubertal stressors can induce long-lasting changes in reproductive behaviors, as well as changes in the expression of sex steroid receptors known to regulate these behaviors.