Intrahypothalamic 5,7-dihydroxytryptamine facilitates feminine sexual behavior and decreases [3H]imipramine binding and 5-HT uptake.

5,7-Dihydroxytryptamine (5,7-DHT) injected into the hypothalamus facilitated feminine sexual behavior in ovariectomized, estrogen-treated female rats beginning 9 days post-lesion. 5,7-DHT treatment was associated with decreased [3H]5-HT but not [3H]NE uptake in the whole hypothalamus and with decreased [3H]-imipramine binding in some hypothalamic nuclei. These data provide the first demonstration using chemical lesions that 5-HT neurons may exert tonic inhibition on hormone-mediated feminine sexual behavior.