Testosterone induced mounting behavior in adult female rats born in litters of different female to male ratios.
Female rats can show mounting behavior towards isosexual or heterosexual conspecifics. The present experiments were designed to study whether the prenatal presence of male fetuses would affect display of this mounting behavior in adulthood. Therefore mounting behavior, after gonadectomy and during continuous treatment with testosterone propionate (TP) was studied in female rats which were born in litters without male siblings ("all female" litters) and in litters with a variable number of male siblings. Litter composition at birth did not affect display of adult mounting behavior during protracted tests (a total of 6 tests during 8 weeks of treatment with TP). The data indicate that TP induced mounting behavior in adulthood occurs independent of the prenatal presence of male fetuses. If mounting behavior in adulthood has to be "organized" by prenatally present androgen (the current way of thinking), then the present data indicate that female rat fetuses provide themselves with these hormones. It would then seem inappropriate to judge adult mounting behavior as a sign of "masculinization" of the rat brain.
D000818:Animals; D004971:Estrus; D005260:Female; D008297:Male; D011247:Pregnancy; D051381:Rats / Q000235:genetics*; D011919:Rats, Inbred Strains; D012744:Sex Ratio; D012726:Sexual Behavior, Animal / Q000187:drug effects*; D013739:Testosterone / Q000494:pharmacology*
D013739:Testosterone