EFFECTS OF BRAIN TESTOSTERONE IMPLANTS ON APPETITIVE AND CONSUMMATORYCOMPONENTS OF MALE SEXUAL-BEHAVIOR IN JAPANESE-QUAIL

Aromatization of testosterone (T) into an estrogen is necessary for th e activation of consummatory and appetitive sexual behavior in male Ja panese quail. T action within the medial preoptic nucleus (POM) is nec essary and sufficient to activate consummatory behavior, and some evid ence suggests that POM might be involved in the control of appetitive behavior, but other brain regions, such as the bed nucleus of the stri a terminalis (BST), an area that contains a dense population of aromat ase-immunoreactive neurons, are also likely to be involved. This study was performed to assess the effects of stereotaxic T implants targeti ng either the POM or the BST on the activation of both components of s exual behavior in castrated male quail. Appetitive sexual behavior was measured by an acquired social proximity response in which a male wil l approach a window providing visual access to a female after the wind ow has been repeatedly paired with physical access to a female and the possibility to freely interact with her. Rhythmic cloacal sphincter m ovements that are produced by the male when given visual access to a f emale were used as another measure of appetitive sexual behavior that does not appear to depend on sexual learning. The experiments confirme d that copulation is necessary for males to develop the social proximi ty response that is used to measure the appetitive sexual behavior. T implants in the POM activated both components of sexual behavior, sugg esting that these components cannot be completely dissociated. In cont rast, T implants located within the BST did not affect either componen t, but because implants in the BST did not activate copulatory behavio r, these results do not preclude a role for BST in the expression of a previously acquired appetitive sexual behavior. (C) 1998 Elsevier Sci ence Inc.