Effects of ethanol on social approach and 50 kHz ultrasonic vocalization production in adolescent male Sprague-Dawley rats.

Low doses of ethanol have been shown to facilitate social behavior in adolescent rats. The present study sought to investigate whether this ethanol effect is associated with increases in the incentive salience of social stimuli when assessed via approach behavior toward a peer (separated from the experimental animal by a mesh barrier) and 50 kHz ultrasonic vocalization (USV) production in that context. A 0.5 g/kg ethanol dose was found to increase social approach/investigation of adolescent male Sprague-Dawley rats during the first 5 min of the 10 min test whereas 50 kHz USV production was elevated by 0.25 g/kg during the last 5 min of testing. 50 kHz USV production and social approach were generally not correlated, indicating a clear dissociation between these measures. This is the first study to demonstrate that ethanol-induced social facilitation in adolescents is associated with an ethanol-induced increase in the incentive salience of social stimuli.