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 derived from the nucleus accumbens. This study was aimed at determining the extent to which these effects are generalizable to opiate-induced feeding. Rats were tested for their feeding response to morphine following chronic interference with DAergic transmission with the long-acting neuroleptic, flupenthixol decanoate (FLU). It was found that FLU-treated animals showed an enhanced feeding response to morphine following three and four weeks of DA blockade, but not on weeks 1 and 2. Neither morphine treatment in FLU-control animals nor chronic FLU treatment alone produced any such time-dependent facilitation in feeding. The results indicate that the increased sensitivity to the rewarding effects of opiates following chronic DA blockade is generalizable to opiate-induced feeding.
Vaccarino
F J
FJ
Department of Psychology, University of Toronto, Ontario, Canada.
Mogil
J S
JS
Stinus
L
L
D000818:Animals; D001835:Body Weight / Q000187:drug effects; D004298:Dopamine / Q000378:metabolism*; D018492:Dopamine Antagonists; D004357:Drug Synergism; D004435:Eating / Q000187:drug effects*; D005475:Flupenthixol / Q000031:analogs & derivatives* / Q000494:pharmacology; D008297:Male; D009020:Morphine / Q000378:metabolism / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D015430:Weight Gain
D018492:Dopamine Antagonists; C007761:flupenthixol decanoate; D009020:Morphine; D005475:Flupenthixol; D004298:Dopamine