Regulation of sexual odor preference by sex steroids in the posterodorsal medial amygdala in female rats.
Our previous study in male rats demonstrated that bilateral administration of flutamide, an androgen receptor (AR) antagonist, into the posterodorsal medial amygdala (MePD) increased the time sniffing male odors to as high as that sniffing estrous odors, eliminating the preference for estrous odors over male odors. This made us speculate that under blockade of AR in the MePD, testosterone-derived estrogen acting on the same brain region arouses interest in male odors which is otherwise suppressed by concomitant action of androgen. In cyclic female rats, endogenous androgen has been thought to be involved in inhibitory regulation of estrogen-activated sexual behavior. Thus, in the present study, we investigated the possibility that in female rats the arousal of interest in male odors is also normally regulated by both estrogen and androgen acting on the MePD, as predicted by our previous study in male rats. Implantation of either the estrogen receptor blocker tamoxifen (TX) or a non-aromatizable androgen 5α-dihydrotestosterone (DHT) into the MePD of ovariectomized, estrogen-primed female rats eliminated preference for male odors over estrous odors by significantly decreasing the time sniffing male odors to as low as that sniffing estrous odors. The subsequent odor discrimination tests confirmed that the DHT and TX administration did not impair the ability to discriminate between male and estrous odors. These results suggest that in estrous female rats estrogen action in the MePD plays critical roles in the expression of the preference for male odors while androgen action in the same brain region interferes with the estrogen action.
['Fujiwara|Masaya|M|', 'Nitta|Asano|A|', 'Chiba|Atsuhiko|A|']
D000679:Amygdala D000818:Animals D002755:Choice Behavior D066276:Corticomedial Nuclear Complex D013196:Dihydrotestosterone D004967:Estrogens D004971:Estrus D005260:Female D005485:Flutamide D008297:Male D008393:Marriage D009812:Odorants D051381:Rats D020318:Rats, Long-Evans D011944:Receptors, Androgen D012725:Sexual Behavior D012726:Sexual Behavior, Animal D013739:Testosterone
Sexual odor preference Amygdala Female rats Androgen Estrogen