Single dose of a dopamine agonist impairs reinforcement learning in humans: Behavioral evidence from a laboratory-based measure of reward responsiveness
| Autor: | Erika M. Cowman Schetter, Diane L. Santesso, Michael J. Frank, Petra E. Pajtas, A. Eden Evins, Melissa A. Culhane, Diego A. Pizzagalli |
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| Rok vydání: | 2007 |
| Předmět: |
Adult
Male Agonist Reinforcement Schedule medicine.drug_class media_common.quotation_subject Administration Oral Blood Pressure Dizziness Dopamine agonist Article Discrimination Learning Reward system Pramipexole Sex Factors Double-Blind Method Reward Dopamine Reaction Time medicine Humans Benzothiazoles media_common Pharmacology Behavior Chi-Square Distribution Receptors Dopamine D2 Addiction Dopaminergic Age Factors Receptors Dopamine D3 Association Learning Nausea Dopamine receptor Female Psychology Neuroscience Algorithms medicine.drug |
| Zdroj: | Psychopharmacology. 196:221-232 |
| ISSN: | 1432-2072 0033-3158 |
| DOI: | 10.1007/s00213-007-0957-y |
| Popis: | The dopaminergic system, particularly D2-like dopamine receptors, has been strongly implicated in reward processing. Animal studies have emphasized the role of phasic dopamine (DA) signaling in reward-related learning, but these processes remain largely unexplored in humans.To evaluate the effect of a single, low dose of a D2/D3 agonist--pramipexole--on reinforcement learning in healthy adults. Based on prior evidence indicating that low doses of DA agonists decrease phasic DA release through autoreceptor stimulation, we hypothesized that 0.5 mg of pramipexole would impair reward learning due to presynaptic mechanisms.Using a double-blind design, a single 0.5-mg dose of pramipexole or placebo was administered to 32 healthy volunteers, who performed a probabilistic reward task involving a differential reinforcement schedule as well as various control tasks.As hypothesized, response bias toward the more frequently rewarded stimulus was impaired in the pramipexole group, even after adjusting for transient adverse effects. In addition, the pramipexole group showed reaction time and motor speed slowing and increased negative affect; however, when adverse physical side effects were considered, group differences in motor speed and negative affect disappeared.These findings show that a single low dose of pramipexole impaired the acquisition of reward-related behavior in healthy participants, and they are consistent with prior evidence suggesting that phasic DA signaling is required to reinforce actions leading to reward. The potential implications of the present findings to psychiatric conditions, including depression and impulse control disorders related to addiction, are discussed. |
| Databáze: | OpenAIRE |
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