Contrasting effects of dopaminergic blockade on MDMA and d-amphetamine conditioned taste aversions.
A series of experiments examined the role of dopamine in the conditioned taste aversion (CTA) produced by 3,4-methylenedioxymethamphetamine (MDMA) and d-amphetamine in rats. The CTA induced by MDMA (1.0 mg/kg) was unaffected by the D1 dopamine receptor antagonist SCH23390 (0.3 or 0.6 mg/kg), the D2 receptor antagonist raclopride (0.3 or 0.6 mg/kg), SCH23390 and raclopride combined (both 0.3 or 0.6 mg/kg), or the D1/D2 receptor antagonist haloperidol (0.4 mg/kg). In contrast, the CTA produced by d-amphetamine (0.5 mg/kg) was attenuated by SCH23390 and raclopride combined (both 0.3 mg/kg) as well as haloperidol (0.4 mg/kg), but not by SCH23390 (0.3 or 0.6 mg/kg) or raclopride (0.3 or 0.6 mg/kg) alone. These results suggest that dopamine plays different roles in MDMA and amphetamine CTAs, and that the D1 and D2 receptors independently mediate the aversive effect of amphetamine in CTA.
Lin
H Q
HQ
Department of Pharmacology, University of Sydney, N.S.W., Australia.
McGregor
I S
IS
Atrens
D M
DM
Christie
M J
MJ
Jackson
D M
DM
D015104:3,4-Methylenedioxyamphetamine / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects*; D001552:Benzazepines / Q000494:pharmacology; D003913:Dextroamphetamine / Q000494:pharmacology*; D018492:Dopamine Antagonists; D065127:Dopamine D2 Receptor Antagonists; D006220:Haloperidol / Q000494:pharmacology; D008297:Male; D018817:N-Methyl-3,4-methylenedioxyamphetamine; D020891:Raclopride; D051381:Rats; D017208:Rats, Wistar; D017447:Receptors, Dopamine D1 / Q000037:antagonists & inhibitors; D012457:Salicylamides / Q000494:pharmacology; D013649:Taste / Q000187:drug effects*
D001552:Benzazepines; D018492:Dopamine Antagonists; D065127:Dopamine D2 Receptor Antagonists; D017447:Receptors, Dopamine D1; D012457:Salicylamides; D020891:Raclopride; D015104:3,4-Methylenedioxyamphetamine; D006220:Haloperidol; D018817:N-Methyl-3,4-methylenedioxyamphetamine; D003913:Dextroamphetamine