Septal lesions: effects on lordosis behavior and pattern of gonadotropin release

Septal lesions increase behavioral responsiveness to estrogen of male, female, and androgen-sterilized female (ASF) rats as measured by lordosis behavior. Male and ASF animals normally show low levels of female sexual receptivity when compared to normal female rats. However, the level of female sexual behavior in male and ASF rats with septal lesions is comparable to that of highly receptive female rats. Progesterone facilitates the estrogen-induced female sexual behavior of female, but not male or ASF, animals. Andrenalectomy had no effect on the increased behavioral sensitivity to estrogen induced by septal lesions. Amygdala lesions, comparable in size to septal lesions, did not facilitate female sexual behavior. The male or female pattern of gonadotropin release is not affected by septal lesions, indicating a disassociation between the regulation of gonadotropin release and sexual behavior. Since septal lesions facilitate lordosis behavior in rats, the septal region appears to exert a tonic inhibition on female sexual behavior.