CHRONIC DOPAMINE ANTAGONISM FACILITATES OPIATE-INDUCED FEEDING

Chronic interference with dopamine (DA) transmission has been found to facilitate opiate reward and opiate-induced behavioral activation der ived from the nucleus accumbens. This study was aimed at determining t he extent to which these effects are generalizable to opiate-induced f eeding, Rats were tested for their feeding response to morphine follow ing chronic interference with DAergic transmission with the long-actin g neuroleptic, flupenthixol decanoate (FLU). It was found that FLU-tre ated animals showed an enhanced feeding response to morphine following three and four weeks of DA blockade, but not on weeks 1 and 2. Neithe r morphine treatment in FLU-control animals nor chronic FLU treatment alone produced any such time-dependent facilitation in feeding. The re sults indicate that the increased sensitivity to the rewarding effects of opiates following chronic DA blockade is generalizable to opiate-i nduced feeding.