Acute effects of ethanol on behavior of adolescent rats: Role of social context

Background: First experiences with alcohol in humans occur predominantly in adolescence, and to a large extent the attractiveness of alcohol at this a ge is based on its ability to facilitate certain forms of social behavior ( social facilitation). Adolescence is strongly marked by a focus on peer rel ationships, and the social nature of the situation plays an important role in responsiveness to alcohol. Peer-directed social activity of adolescent r ats may hi: a valuable experimental model for the study of ethanol-induced changes in social behavior and assessment of the role of the social context in responsiveness to ethanol. Method: In the present study we used a modified dyad social interaction tes t to characterize acute effects of ethanol on different forms of social beh avior (social investigation, contact behavior, and play) and social motivat ion (preference/avoidance of a peer) in adolescent rats. Ethanol effects on behavior directed toward a peer were compared with those induced by exposu re to an inanimate novel object. Results: In the social context, the effects of ethanol were dose-dependent and biphasic. Low doses of ethanol (0.25-0.75 g/kg) produced apparent socia l facilitation (increased social activity and enhanced social preference), whereas higher doses (3 and 4 g/kg) caused social inhibition (decreased soc ial activity and avoidance of a peer). This pattern was not observed for a nonsocial stimulus: Although overall activity in the nonsocial context was suppressed by 2 and 3 g/kg of ethanol, 0.5 g/kg of ethanol did not activate overall activity directed to the inanimate object. Conclusions: These findings demonstrate that the social nature of the testi ng situation plays an important role in responsiveness to alcohol in adoles cence, especially to its activating effects. The results suggest also that the study of ethanol effects on social behavior of adolescent rats may be a n effective tool for the study of adolescent alcohol use and abuse.