Sexual behavior during late adolescence in the female rat: reduced sensitivity to cocaine´s effects when compared to adulthood

AGRATI, D; BEDO, G; ANTONELLI MC; MACHADO, L; URIARTE, N; FERREIRA, A; MARIN, G; ZULUAGA, MJ

Montreal

Simposio; Meeting of the Society for Behavioral Neuroendocrinology; 2016

Society for Behavioral Neuroendocrinology

Recently we observed that during late proestrus, adolescent female rats are highly sexual motivated, but they express a differential pattern of proceptive behaviors when compared to adults. Because the dopaminergic mesocorticolimbic system is implicated in the expression of motivated behaviors and is still maturing during adolescence, this study aimed to 1) compare the effect of cocaine on the sexual behavior of adolescent and adult females, and 2) determine the expression of D1 and D2 dopamine receptors in ventral and dorsal striatum of these females. Therefore, we assessed the preference for male vs female in a Y-maze and the sexual behavior in response to a male of late adolescent (45-55 days-old) and adult (100-120 days-old) rats during late proestrus after the administration of cocaine (0.0, 5.0, 10.0 and 20.0 mg/kg i.p., -20 min). Besides, we are analyzing D1- and D2-receptores binding by autoradiography employing (H3)-SCH-23390 and (H3)-nemonapride, respectively. C! ocaine´s administration did not affect the clear preference for the male over the female of late adolescent and adult rats; however the highest dose of cocaine reduced sexual proceptivity and receptivity of adult, but not late adolescent, females. The effect of cocaine on ambulation was also higher in adult females when compared to adolescents. Although preliminary, autoradiography data suggest age-related differences in the expression of D1- and D2-receptors in the dorsomedial striatum and the shell of the nucleus accumbens. Thus, during proestrus, late adolescent females are less sensitive than adults to the effects of cocaine on sexual behavior, and this difference may be associated with a differential expression of dopamine receptors in the striatum of sexually active adolescent and adult rats. These results provide elements for understanding maturation processes of the dopaminergic system and its role in the regulation of female?s sexual behavior at different! lifetime periods. Financial support: CSIC I+D, SNI, PEDECIBA