EFFECTS OF ALPHA-ADRENERGIC AND BETA-ADRENERGIC ANTAGONISTS ON AGGRESSIVE-BEHAVIOR IN MALE-MICE

The effects of a variety of alpha and beta adrenergic antagonists were examined on the social encounters of isolated male mice with anosmic male partners. A range of alpha antagonists, including phentolamine, p razosin, and yohimbine, all suppressed social aggression. A range of b eta antagonists, including propranolol, atenolol, metaprolol, and ICI 118,551, also reduced this type of attack. Ethological assessment of t he lowest effective dose of these adrenergic antagonists revealed a ma rked inhibitor action on offensive, social, and nonsocial behavior, wh ile defensive responses and immobility were enhanced. It is concluded that the noradrenergic system has a significant non-specific role in m ediating intermale aggression via both alpha and beta adrenergic recep tor subtypes. (C) 1993 Wiley-Liss, Inc.