Cocaine self-administration is increased by both D1 and D2 dopamine antagonists.
Rats were trained to self-administer cocaine on a fixed-ratio 5 schedule of reinforcement with a 1-min time-out period following each infusion. Cocaine was available at doses of either 0.1, 0.3 or 1.0 mg/kg/infusion. A low dose (3 microgram/kg) of the D1 antagonist SCH23390 caused an increase in cocaine self-administration which was more prominent at higher, as compared to lower, doses of cocaine. Higher doses of SCH23390 generally caused decreases in self-administration which may in part be due to the response-decreasing properties of this agent. The D2 antagonist spiperone generally caused an increase in self-administration of cocaine. These data suggest that cocaine reinforcement depends upon both D1 and D2 receptor subtypes.
Corrigall
W A
WA
Addiction Research Foundation, Toronto, Ontario, Canada.
Coen
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KM
D000818:Animals; D001552:Benzazepines / Q000494:pharmacology; D003042:Cocaine / Q000494:pharmacology*; D003216:Conditioning, Operant / Q000187:drug effects; D018492:Dopamine Antagonists; D004305:Dose-Response Relationship, Drug; D008297:Male; D051381:Rats; D017447:Receptors, Dopamine D1; D017448:Receptors, Dopamine D2; D012054:Reinforcement, Psychology; D012646:Self Administration; D013134:Spiperone / Q000494:pharmacology
D001552:Benzazepines; D018492:Dopamine Antagonists; D017447:Receptors, Dopamine D1; D017448:Receptors, Dopamine D2; D013134:Spiperone; D003042:Cocaine