ANDROGEN-DEPENDENT SEX-DIFFERENCES IN THE HYPOTHALAMIC SEROTONINERGICSYSTEM

This study has attempted to fulfil our knowledge on the sex difference s in the hypothalamic serotoninergic (5-HT) system in adult rats, and also to evaluate the role of neonatal androgens in the appearance of t his sexual dimorphism. Such integrative characteristics of the 5-HT sy stem as 5-HT content and specific uptake were estimated and compared i n the anterior and middle hypothalami in intact adult females and male s, as well as in neonatally castrated adult males. According to our da ta, the 5-HT content and [H-3]5-HT specific uptake both in the anterio r and middle hypothalami of intact females exceeded significantly thos e in intact males. Neonatal castration of males resulted in an increas e of the 5-HT content and [3H]5-HT uptake in both hypothalamic regions up to their levels in intact Females. Thus, the present study provide s new information on the sex differences in the hypothalamic 5-HT syst em, which are apparently related to the neonatal masculinization of th e hypothalamus.