title: Serotonin-1A receptor activity and expression modulate adolescent anabolic/androgenic steroid-induced aggression in hamsters.
abstract: Repeated high dose (5.0 mg/kg) anabolic/androgenic steroid exposure during adolescence stimulates offensive aggression in male Syrian hamsters. These studies examined whether anabolic/androgenic steroid-induced aggression was regulated by the activity and expression of serotonin (5HT) type-1A receptors. In a first experiment, adolescent male hamsters were treated with a mixture of anabolic/androgenic steroids and then scored for offensive aggression in the absence or presence of the selective 5HT1A receptor agonist R(+)-8-OH-DPAT (0.1-0.6 mg/kg). Adolescent anabolic/androgenic steroid-treated hamsters displayed high levels of offensive aggression that could be reversed by enhancing the activity of 5HT1A receptors. The agonist R(+)-8-OH-DPAT dose-dependently reduced the steroid-induced aggressive response, with significant reductions in aggression observed at 0.1-0.3 mg/kg. In a second set of experiments, adolescent hamsters were administered anabolic/androgenic steroids or vehicle and then examined for 5HT1A receptor localization and expression in regions of the brain important for aggression control. Hamsters treated with anabolic/androgenic steroids showed significant decreases in 5HT1A receptor-immunoreactive staining and protein levels in the anterior hypothalamus (i.e., a brain region central to the control of offensive aggression in hamsters) with no concomitant decrease in the number of 5HT1A receptor-expressing neurons. Together, these data support a role for site-specific down-regulation of 5HT1A receptor activity in adolescent anabolic/androgenic steroid-induced aggression.
authors.affiliation: Behavioral Neuroscience Program, Department of Psychology, 125 Nightingale Hall, Northeastern University, Boston, MA 02115, USA.
authors.forename: Lesley A
authors.initials: LA
authors.lastname: Ricci
authors.forename: Khampaseuth
authors.initials: K
authors.lastname: Rasakham
authors.forename: Jill M
authors.initials: JM
authors.lastname: Grimes
authors.forename: Richard H
authors.initials: RH
authors.lastname: Melloni
mesh_terms: D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000494:pharmacology; D000374:Aggression / Q000187:drug effects*; D045930:Anabolic Agents / Q000494:pharmacology*; D000728:Androgens / Q000494:pharmacology*; D000818:Animals; D006224:Cricetinae; D004305:Dose-Response Relationship, Drug; D007150:Immunohistochemistry; D008297:Male; D008647:Mesocricetus; D044282:Receptor, Serotonin, 5-HT1A / Q000378:metabolism / Q000502:physiology*; D058825:Serotonin 5-HT1 Receptor Agonists
chemical_list: D045930:Anabolic Agents; D000728:Androgens; D058825:Serotonin 5-HT1 Receptor Agonists; D044282:Receptor, Serotonin, 5-HT1A; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin