Effect of Ro 15-4513 on ethanol-induced conditioned place preference

The benzodiazepine receptor inverse agonist Ro 15-4513 reverses a number of ethanol's effects, including its reinforcing properties as measured through self-administration. The present study examined the effect of this putative ethanol antagonist in a place conditioning design that has been shown to be sensitive to ethanol's rewarding properties in mice. Using an unbiased differential conditioning procedure, DBA/2J mice received, on alternate days, pairings of a distinctive floor stimulus (CS+) with either ethanol (2 g/kg), Ro 15-4513 (3 mg/kg), or a combination of ethanol and Ro 15-4513. On alternate days, a different distinctive floor stimulus (CS-) was paired with vehicle. Under these conditions, ethanol produced a conditioned place preference that was unaffected by Ro 15-4513. Ro 15-4513 alone did not produce either a place preference or aversion. Ro 15-4513 did produce reductions in locomotor activity during conditioning, indicating it was behaviorally active. These results indicate that a dose of Ro 15-4513 that alters general activity does not affect ethanol reward.