Serotonin-dopamine interactions in the control of conditioned reinforcement and motor behavior.
These studies addressed the question of serotonin (5-HT)-dopamine (DA) interactions with regard to reward-related behavior and motor activity in rats. The first experiment evaluated the effect of chronic treatment with fluoxetine (7 mg/kg/day), a serotonin-selective reuptake inhibitor, and buproprion (15 mg/kg/day), a dopamine reuptake inhibitor, on responding for conditioned reinforcement (CR). Chronic fluoxetine, but not buproprion, enhanced CR responding, and also potentiated cocaine-induced increases in CR responding. In the second experiment, animals received intra-accumbens infusions of either 5-HT (0, 1, 5, and 10 microg) or DA (10, 20 microg) prior to the conditioned reinforcement test. Dopamine, but not 5-HT, selectively facilitated CR responding, although 5-HT non-specifically increased responding as well. In the third and fourth experiments, it was demonstrated that intra-accumbens 5-HT causes increased motor activity, which was partially blocked by DA antagonists. The results suggest that chronically increased levels of 5-HT may facilitate reward-related behavior, but most likely via indirect modulatory mechanisms affecting general arousal and motor tone.
Sasaki-Adams
D M
DM
Department of Psychiatry, University of Wisconsin-Madison Medical School, Madison, WI 53719, USA.
Kelley
A E
AE
D000818:Animals; D001552:Benzazepines / Q000008:administration & dosage / Q000494:pharmacology; D016642:Bupropion / Q000494:pharmacology; D003216:Conditioning, Operant / Q000187:drug effects*; D004298:Dopamine / Q000008:administration & dosage / Q000494:pharmacology*; D018492:Dopamine Antagonists / Q000008:administration & dosage / Q000494:pharmacology; D018765:Dopamine Uptake Inhibitors / Q000494:pharmacology; D004347:Drug Interactions; D005473:Fluoxetine / Q000494:pharmacology; D008297:Male; D008845:Microinjections; D009043:Motor Activity / Q000187:drug effects*; D009714:Nucleus Accumbens / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012054:Reinforcement, Psychology; D012701:Serotonin / Q000008:administration & dosage / Q000494:pharmacology*; D017367:Selective Serotonin Reuptake Inhibitors / Q000494:pharmacology
D001552:Benzazepines; D016642:Bupropion; D004298:Dopamine; D018492:Dopamine Antagonists; D018765:Dopamine Uptake Inhibitors; D005473:Fluoxetine; D012701:Serotonin; D017367:Selective Serotonin Reuptake Inhibitors