Anxiogenic effects during withdrawal from acute ethanol in adolescent and adult rats

Elevated signs of anxiety are observed in adult rodents during withdrawal from chronic as well as acute ethanol exposure. To determine whether adolescents, in addition to their insensitivity to a number of acute ethanol effects, might likewise be hyposensitive to these anxiogenic manifestations of withdrawal from an acute ethanol challenge, the behavior of adolescent and adult male Sprague-Dawley rats was assessed in an elevated plus maze (EPM) 18 h following intraperitoneal challenge with 4 g/kg ethanol. Adult but not adolescent animals demonstrated evidence of anxiety in the plus maze during acute ethanol withdrawal. To ensure that this finding did not merely reflect age differences in ethanol clearance, clearance times at each age were determined, with additional adolescents tested at the same time postclearance as the adults were previously. Adolescents still failed to demonstrate anxiogenic signs of withdrawal. Suppression of activity during the withdrawal test, however, was evident in animals of both ages. A relative resistance to the anxiogenic effects associated with acute ethanol withdrawal during adolescence could serve as a permissive factor for development of binge drinking patterns among human adolescents. (C) 2003 Elsevier Science Inc. All rights reserved.