Haloperidol administered subchronically reduces the alcohol-deprivation effect in mice

During the pre-experimental phase, hybrid (CBA x C57BL) male mice having had 16 weeks free access to food, water and flavored 30% alcohol were deprived of alcohol for 3 days. The next day they were given free choice between similarly flavored water and 30% alcohol. The mice were divided into two subgroups having (HD) or lacking (LD) the deprivation-induced elevation in alcohol intake during the first 1.5 h of renewed access compared with their intake during the last 22.5 h of first postdeprivation day. In Experiment 1, alcohol naive, LD, and HD mice received daily injections of haloperidol (Haldol; 1 mg/kg) or vehicle during 14 days of abstinence. The behavior of the mice was evaluated in an exploratory cross-maze and inescapable slip funnel test a day after the 13th injection (before the 14th injection). On the first postinjection day, the mice were again given a free choice between flavored water and alcohol. In Experiment 2, all the mice were administered with vehicle during the first 13 days of abstinence. On 14th day, they received an injection of haloperidol (1 mg/kg) or vehicle and a day later were given choice between flavored water and alcohol. Unlike a single injection, the subchronic administration of haloperidol lowered the alcohol intake by HD mice with a more prominent decrease seen during the first 1.5 h than during the last 22.5 h of first postdeprivation day. The alcohol-deprivation effect in HD mice decreased by 79% after subchronic haloperidol. No significant change in alcohol intake was found in alcohol-naive and LD mice. Water intake did not vary systematically. Among the groups, the effect of subchronic haloperidol on the alcohol-deprivation effect did not parallel changes in most of the measures of exploratory or avoidance behavior. It is proposed that haloperidol administered subchronically may attenuate motivation for alcohol.