Feminine Behavior in Neonatally Castrated and Estrogen-Treated Male Rats

Abstract

Male rats castrated within 4 days after birth are behaviorally feminized. On the other hand, intact or castrated males given estrogen neonatally show little estrous behavior in adulthood. Thus, feminization is induced by lack of neonatal androgen rather than by the presence of estrogen. Estrogen administered to newborn rats suppresses feminization.