Anabolic steroids alter the physiological activity of aggression circuits in the lateral anterior hypothalamus.
Syrian hamsters exposed to anabolic/androgenic steroids (AAS) during adolescence consistently show increased aggressive behavior across studies. Although the behavioral and anatomical profiles of AAS-induced alterations have been well characterized, there is a lack of data describing physiological changes that accompany these alterations. For instance, behavioral pharmacology and neuroanatomical studies show that AAS-induced changes in the vasopressin (AVP) neural system within the latero-anterior hypothalamus (LAH) interact with the serotonin (5HT) and dopamine (DA) systems to modulate aggression. To characterize the electrophysiological profile of the AAS aggression circuit, we recorded LAH neurons in adolescent male hamsters in vivo and microiontophoretically applied agonists and antagonists of aggressive behavior. The interspike interval (ISI) of neurons from AAS-treated animals correlated positively with aggressive behaviors, and adolescent AAS exposure altered parameters of activity in regular firing neurons while also changing the proportion of neuron types (i.e., bursting, regular, irregular). AAS-treated animals had more responsive neurons that were excited by AVP application, while cells from control animals showed the opposite effect and were predominantly inhibited by AVP. Both DA D2 antagonists and 5HT increased the firing frequency of AVP-responsive cells from AAS animals and dual application of AVP and D2 antagonists doubled the excitatory effect of AVP or D2 antagonist administration alone. These data suggest that multiple DA circuits in the LAH modulate AAS-induced aggressive responding. More broadly, these data show that multiple neurochemical interactions at the neurophysiological level are altered by adolescent AAS exposure.
['Morrison|T R|TR|', 'Sikes|R W|RW|', 'Melloni|R H|RH|']
D000200:Action Potentials D000374:Aggression D045930:Anabolic Agents D000818:Animals D065127:Dopamine D2 Receptor Antagonists D007026:Hypothalamic Area, Lateral D007032:Hypothalamus, Anterior D008297:Male D008647:Mesocricetus D009474:Neurons D017448:Receptors, Dopamine D2 D012457:Salicylamides D012701:Serotonin D013256:Steroids D014667:Vasopressins
aggression hypothalamus vasopressin serotonin dopamine development