Sensitization of haloperidol-induced hypophagia is contingent on behavioral experience with food

Abstract

Groups of rats were given injections of haloperidol (0.31 mg/kg) at weekly intervals either before or after access to sweetened milk. Control groups were given injections of saline. At the end of the chronic regimen, all groups received a single injection of haloperidol (0.15 mg/kg) prior to milk access. Rats injected with the drug before milk during the chronic phase showed a progressive decrease in milk intake. When subsequently challenged with a lower dose, this group ingested less milk than any of the other groups, which did not differ from one other. These results demonstrate that sensitization of haloperidol-induced hypophagia is contingent on experience with milk while in the drugged state.