Repeated anabolic-androgenic steroid treatment during adolescence increases vasopressin V1A receptor binding in Syrian hamsters:: Correlation with offensive aggression

Repeated anabolic-androgenic steroid treatment during adolescence increases hypothalamic vasopressin and facilitates offensive aggression in male Syrian hamsters (Mesocricetus auratus). The current study investigated whether anabolic-androgenic steroid exposure during this developmental period influenced vasopressin VIA receptor binding activity in the hypothalamus and several other brain areas implicated in aggressive behavior in hamsters. To test this, adolescent male hamsters were administered anabolic steroids or sesame oil throughout adolescence, tested for offensive aggression, and examined for differences in vasopressin VIA receptor binding using in situ autoradiography. When compared with control animals, aggressive, adolescent anabolic steroid-treated hamsters showed significant increases (20-200%) in the intensity of vasopressin VIA receptor labeling in several aggression areas, including the ventrolateral hypothalamus, bed nucleus of the stria terminalis, and lateral septum. However, no significant differences in vasopressin VIA receptor labeling were found in other brain regions implicated in aggressive responding, most notably the lateral zone from the medial preoptic area to anterior hypothalamus and the corticomedial amygdala. These data suggest that adolescent anabolic steroid exposure may facilitate offensive aggression by increasing vasopressin VIA receptor binding in several key areas of the hamster brain. (C) 2002 Elsevier Science (USA).