title: Discriminative stimulus effects of dopaminergic agents in rhesus monkeys.
abstract: Recent reports have shown that treatment with dopamine reuptake inhibitors can selectively decrease responding maintained by low doses of cocaine in rhesus monkeys. This may occur because response-independent delivery of a reuptake inhibitor and response-dependent cocaine have common effects. One behavioral effect that dopamine reuptake inhibitors and cocaine share is their ability to serve as a discriminative stimulus. To compare discriminative effects of several dopaminergic agents with their ability to attenuate cocaine-maintained responding, three rhesus monkeys were first trained to discriminate intravenous injections of cocaine (0.1 mg/kg) from saline. Following generalization testing with various doses of cocaine (0.001-1.0 mg/kg), the relative potencies of phentermine (0.03-1.0 mg/kg), d-amphetamine (0.01-1.0 mg/kg), GBR 12,909 (0.01-1.0 mg/kg), and buspirone (0.03-0.56 mg/kg) to substitute for cocaine were assessed. Each drug except buspirone resulted in predominantly cocaine-appropriate responding at doses that were generally without rate-decreasing effect. The ED50 for the ability of these drugs to substitute for cocaine exhibited the same rank order as that for their effectiveness in decreasing cocaine-maintained responding. Thus, the current results show that the potencies of dopaminergic drugs to decrease cocaine-maintained responding and substitute for cocaine in a drug discrimination paradigm are related.
authors: Behavioral Pharmacology Unit, LMC/NIDDK/NIH, Bethesda, MD 20892, USA.
authors: L
authors: L
authors: Koetzner
authors: A L
authors: AL
authors: Riley
authors: J R
authors: JR
authors: Glowa
mesh_terms: D000818:Animals; D003042:Cocaine / Q000008:administration & dosage / Q000494:pharmacology; D003913:Dextroamphetamine / Q000494:pharmacology; D004192:Discrimination, Psychological / Q000187:drug effects*; D015259:Dopamine Agents / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D008253:Macaca mulatta; D008297:Male; D009294:Narcotics / Q000008:administration & dosage / Q000494:pharmacology; D010645:Phentermine / Q000494:pharmacology; D010879:Piperazines / Q000494:pharmacology; D012646:Self Administration / Q000523:psychology
chemical_list: D015259:Dopamine Agents; D009294:Narcotics; D010879:Piperazines; C043425:vanoxerine; D010645:Phentermine; D003042:Cocaine; D003913:Dextroamphetamine