Sex Difference and Testosterone Modulation: DISCUSSION(9)

27 Mar

The inability of female hamsters to show a neuronal Fos-IR response to vaginal secretions in this brain region is correlated with their lack of male-typical coital responsiveness to adult treatment with testosterone. In experiment 1, female ferrets showed significant increases in neuronal Fos-IR in the BNST and mPOA after exposure to estrous female odors. This result is surprising, in so far as female ferrets are exposed to very low levels of testosterone perinatally and as a result are capable of showing only minimal levels of male-typical coital behavior when given TP and tested in adulthood with estrous females (reviewed in ). Thus female pheromones would not be expected to activate hypothalamic neurons in female conspecifics. proventil inhaler

These odors may affect other, yet-to-be-identified aspects of social interaction among female ferrets. The absence of neuronal Fos-IR responses to female pheromones in the BNST and mPOA of male ferrets (experiment 1 and ref. ) is even more surprising, in light of several reports (reviewed in ) of such effects in male rodents. The absence of a neuronal Fos response in a particular brain region does not necessarily mean that neurons in that region are totally unresponsive to a particular stimulus. The different effects of estrous female pheromones on hypothalamic Fos responses in male rodents and ferrets suggests, however, that significant differences exist in the roles that pheromones play in aspects of social interaction and neuroendocrine function among males of different mammalian orders.