Haloperidol does not alter expression of ethanol-induced conditioned place preference.

A recent experiment (Risinger et al., Psychopharmacology, 107 (1992) 453-456) has shown that haloperidol does not prevent acquisition of ethanol-induced conditioned place preference, suggesting that dopaminergic mechanisms do not mediate the primary rewarding properties of ethanol. The present experiment examined whether haloperidol would prevent the expression of conditioned reward to ethanol-paired stimuli using the place conditioning paradigm. DBA/2J mice received four pairings of a tactile stimulus with ethanol (2 g/kg, IP). A different stimulus was paired with saline. Before preference testing, different groups received one of three doses of haloperidol (0, 0.05 or 0.1 mg/kg); ethanol was not given. Haloperidol produced a dose-dependent decrease in locomotor activity, but did not affect conditioned place preference. These results suggest that expression of ethanol-induced conditioned place preference is mediated by non-dopaminergic mechanisms.