Prenatal exposure of the ovine fetus to androgens reduces the proportion of neurons in the ventromedial and arcuate nucleus that are activated by short-term exposure to estrogen.

In sheep, the steroid control of gonadotropin-releasing hormone (GNRH) release is sexually differentiated such that estrogen can trigger a GNRH surge and attendant reproductive behaviors in the female, but not the male. Furthermore, female lambs that have been exposed to testosterone during a critical window of in utero development are also unable to generate a GNRH surge. This study tests the hypothesis that exposure of the ovine fetus to androgens alters the development of key steroid-receptive neuronal inputs to the GNRH neurons.