Effects of dopamine antagonists with different receptor blockade profiles on morphine-induced place preference in male mice.
The effects of dopamine (DA) antagonists with different selectivity for the DA receptors (SCH 23390, 0.5, 0.25, 0.125 mg/kg; haloperidol, 0.2, 0.1 mg/kg; raclopride, 1.2, 0.6, 0.3 mg/kg; risperidone, 0.4, 0.2, 0.1 mg/kg; U-99194A maleate, 40, 20 mg/kg; clozapine, 2.5, 1.25, 0.625 mg/kg) on the acquisition of place conditioning and morphine-induced conditioned place preference (CPP) were explored in male mice. Morphine (40 mg/kg) produced CPP while SCH 23390, haloperidol and clozapine (highest dose) and risperidone (lowest dose) produced conditioned place aversion (CPA). Raclopride and U-99194A maleate did not produce CPP or CPA. Morphine-induced CPP was reversed by the administration of SCH 23390 and risperidone (all doses), haloperidol (highest dose) and raclopride and clozapine (intermediate and lowest doses). U-99194A maleate did not reverse morphine-induced CPP. These results suggest that the conditioned rewarding effects of morphine are mediated by the different subtypes of DA receptors.
Manzanedo
C
C
Area de Psicobiología, Facultad de Psicología, Universitat de Valencia, Aptdo. 22109,. 46071 Valencia, Spain.
Aguilar
M A
MA
Rodríguez-Arias
M
M
Miñarro
J
J
D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects; D001921:Brain / Q000187:drug effects; D002755:Choice Behavior / Q000187:drug effects*; D003214:Conditioning, Classical / Q000187:drug effects; D018492:Dopamine Antagonists / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D008297:Male; D051379:Mice; D009020:Morphine / Q000494:pharmacology*; D009042:Motivation; D009949:Orientation / Q000187:drug effects*; D011954:Receptors, Dopamine / Q000145:classification / Q000187:drug effects*
D018492:Dopamine Antagonists; D011954:Receptors, Dopamine; D009020:Morphine