APPETITIVE AND CONSUMMATORY MALE SEXUAL-BEHAVIOR IN JAPANESE-QUAIL ARE DIFFERENTIALLY REGULATED BY SUBREGIONS OF THE PREOPTIC MEDIAL NUCLEUS

Central testosterone aromatization is required for the activation of b oth appetitive (ASB) and consummatory (CSB) male sexual behavior in Ja panese quail. There are two major clusters of aromatase immunoreactive (ARO-ir) cells in the rostral forebrain; these outline the nucleus pr eopticus medialis (POM) and the nucleus striae terminalis (BST). We in vestigated the role of these nuclei in the regulation of ASB and CSB. Appetitive male sexual behavior was measured with the use of a learned social proximity procedure that quantified the time spent by a male i n front of a window with a view of a female who was subsequently relea sed into the cage, providing an opportunity for CSB. Males first acqui red the response and then received bilateral electrolytic lesions aime d at the POM or BST, followed by retesting for ASB and CSB. Brain sect ions were stained for ARO-ir, and lesions to the two ARO-ir cell group s were quantitatively characterized. Lesions damaging the POM complete ly abolished CSB and also significantly decreased ASB. Lesions of the rostral BST had no effect on ASB, but moderately decreased CSB. Detail ed anatomical analysis revealed that lesions of a subdivision of the P OM just rostral to the anterior commissure specifically impair CSB, wh ereas lesions that are more rostral to this subdivision induce a sever e deficit in ASB. These data indicate that different subregions of the POM regulate ASB and CSB in a somewhat independent manner, whereas th e BST is only important in the regulation of CSB.