title: Serotonin modulates offensive attack in adolescent anabolic steroid-treated hamsters.
abstract: Chronic anabolic-androgenic steroid (AAS) treatment during adolescence facilitates offensive aggression in male Syrian hamsters (Mesocricetus auratus). The current study assessed whether adolescent AAS-facilitated offensive attack was modulated by serotonin (5-HT) and if AAS exposure during this developmental period influenced 5-HT innervation to areas of hamster brain implicated in aggressive behavior. In a first experiment, hamsters were administered high-dose AAS throughout adolescence, and then scored for offensive attack following the systemic administration of saline or fluoxetine, a selective 5-HT reuptake inhibitor. Saline-treated hamsters showed high levels of offensive attack, while treatment with fluoxetine attenuated the AAS-facilitated aggressive response. In a second experiment,were administered high-dose AAS or sesame oil throughout adolescence, tested for offensive attack and then examined for differences in 5-HT innervation to areas of the hamster brain important for aggression. Aggressive AAS-treated hamsters showed significant reductions in the number of 5-HT immunoreactive (5-HT-ir) varicosities and fibers in several of these areas, most notably the anterior hypothalamus (AH), ventrolateral hypothalamus (VLH) and medial amygdala (MeA). However, no differences in 5-HT afferent innervation were found in other aggression areas, such as the bed nucleus of the stria terminalis (BNST) and lateral septum (LS). Together, these results support a role for altered 5-HT innervation and function in adolescent AAS-facilitated offensive aggression.
authors.affiliation: Behavioral Neuroscience Program, Department of Psychology, 125 Nightingale Hall, Northeastern University, 360 Huntington Avenue, Boston, MA 02115, USA.
authors.forename: Jill M
authors.initials: JM
authors.lastname: Grimes
authors.forename: Richard H
authors.initials: RH
authors.lastname: Melloni
mesh_terms: D000374:Aggression / Q000187:drug effects*; D045930:Anabolic Agents / Q000037:antagonists & inhibitors* / Q000494:pharmacology*; D000818:Animals; D001923:Brain Chemistry / Q000187:drug effects; D006224:Cricetinae; D005473:Fluoxetine / Q000494:pharmacology; D007091:Image Processing, Computer-Assisted; D007150:Immunohistochemistry; D008297:Male; D008647:Mesocricetus; D009412:Nerve Fibers / Q000187:drug effects / Q000502:physiology / Q000648:ultrastructure; D009475:Neurons, Afferent / Q000187:drug effects / Q000502:physiology; D012701:Serotonin / Q000502:physiology*; D017367:Selective Serotonin Reuptake Inhibitors / Q000494:pharmacology
chemical_list: D045930:Anabolic Agents; D005473:Fluoxetine; D012701:Serotonin; D017367:Selective Serotonin Reuptake Inhibitors