This study sought to determine the roles of D1 and D2 receptors in mediating gambling reinforcement in pathological gamblers and controls (n=24/group), and the influence of reward novelty on these effects. Subjects received D2 antagonist, haloperidol (3mg), or D1-D2 antagonist, fluphenazine (3mg) in a placebo-controlled, counterbalanced, two-session design. Incentive motivation and hedonic impact were assessed before and after a 15-min slot machine game. Haloperidol tended to increase pre-game motivation but reduce the priming effect of the slot machine, while fluphenazine increased positive mood ratings but reduced motivation to gamble. Haloperidol effects were stronger when it was received on the first session, while fluphenazine had stronger effects after prior drug-free exposure. Results suggest D1 signaling is central to reward expectancy and motivation to gamble, and that moderate stimulation increases positive affect while reducing motivation to gamble. D1 blockade may also enhance reinforcement of a familiar task by interfering with reward expectancy.
| Identifer | oai:union.ndltd.org:TORONTO/oai:tspace.library.utoronto.ca:1807/42938 |
| Date | 28 November 2013 |
| Creators | Smart, Kelly |
| Contributors | Zack, Martin |
| Source Sets | University of Toronto |
| Language | en_ca |
| Detected Language | English |
| Type | Thesis |
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