This study used the D2-preferring dopamine antagonist, haloperidol (3mg) and D1-D2 antagonist, fluphenazine (3mg) to investigate the roles of D1 and D2 receptors in d-amphetamine (20-mg) reinforcement in humans with (9 M; 7 F) and without (12 M; 4 F) an addictive disorder, in a placebo-controlled, between-within counterbalanced design. To preclude neurotoxicity, pathological gamblers served to evaluate effects of addiction status. Incentive motivation (e.g., Desire to Gamble), hedonic impact (e.g., Liking) and risky decision-making were assessed. Haloperidol reduced Desire to Gamble in controls, whereas fluphenazine reduced Desire in gamblers. Both antagonists reduced hedonic impact in both groups, with fluphenazine exhibiting stronger effects in gamblers. Both antagonists decreased risky decisions in controls but increased risky decisions in gamblers. Results suggest that D1 mediates amphetamine-induced motivation to gamble; D2 mediates amphetamine’s hedonic effects; D1 function is deficient in gamblers; and D2 blockade may reverse a restorative effect of amphetamine in addicted individuals.
| Identifer | oai:union.ndltd.org:TORONTO/oai:tspace.library.utoronto.ca:1807/33558 |
| Date | 27 November 2012 |
| Creators | Tatone, Daniel |
| Contributors | Zack, Martin |
| Source Sets | University of Toronto |
| Language | en_ca |
| Detected Language | English |
| Type | Thesis |
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