Sex Steroids Program Gender Identity

将女性胎儿暴露于过量的睾丸激素（Pren-T）会导致外生殖器阳刚之气和中枢神经系统（CNS）对生殖神经内分泌轴和性典型行为的控制的永久性改变。生殖器男性化的程度并不能很好地反映出睾丸激素在产前的作用。识别发育过程中未来性别行为的非生殖器指标将有助于儿科医生为生殖器模糊的儿童制定更好的治疗方案。这只羊是

Exposing female fetuses to excessive testosterone (Pren-T) causes virilization of the external genitalia and permanent alterations in the central nervous system (CNS) control of the reproductive neuroendocrine axis and sex-typical behaviors. The extent of genital virilization is not a good indicator of the prenatal programming by testosterone. Identification of non-genital indicators of future gendered behavior during development would assist pediatricians in developing better treatment protocols for children with ambiguous genitalia. The sheep is an excellent model in which to study these relationships because required doses of Pren-T for achieving varying amounts of masculinization have been determined, and the pre-pubertal period is sufficiently long that behavioral development can be accurately assessed, yet reproductive maturity occurs within 6-7 months. Because differentiation of some behaviors is evident prior to puberty, we propose to determine which early behaviors accurately predict adult gendered behavior. We expect the behavioral differentiation caused by Pren-T to alter steroid hormone receptors, cytoarchitecture and functional responses in key areas of the CNS. Hypothesis: The timing of Pre-T programs a variety of CNS functions independently of virilization of the genitalia, such that the extent ofvirilization does not accurately predict behavior. In addition, some juvenile behaviors will better predict adult social-sexual behaviors than others. The organization and function of key brain areas involved in social-sexual behaviors will also be programmed by Pren-T. Specific Aims: 1) Test the hypothesis that androgenic and estrogenic affects of T cause juvenile sex-differentiated behaviours that predict adult sexually-dimorphic behaviors and neuroendocrine function. 2) Test the hypothesis that postnatal exposure to estrogen further masculinizes the behavior of females exposed to Pren-T. 3) Test the hypothesis that Pren-T exposure alters the functional neuroanatomy of the amygdala, preoptic area and other sexually-dimorphic hypothalamic nuclei.