Repeated administration of psychostimulant drugs induces a long-term state of sensitization in the mesolimbic dopamine system. This hyperdopaminergic state is associated with enhanced reward-seeking behaviors. Such aberration of incentive motivational processing is suggested to facilitate the initiation and maintenance of compulsive drug-taking behaviors. A defining characteristic of addiction is the persistence to pursue drug reinforcement despite negative consequences associated with administration. Thus, it is likely that addicts frequently experience states of motivational conflict to both seek and avoid the drug. The present study investigated the effects of repeated cocaine exposure on goal-seeking behaviors in rats, utilizing conflict paradigms wherein positive and negative incentive motivations were simultaneously evoked. Here it was shown that cocaine-experienced rats displayed both enhanced approach and avoidance behaviors, depending upon the conditions put forth in each paradigm. The results contribute to elucidating the consequences of drug administration upon basic motivational processes that may influence compulsive drug-taking behaviors.
| Identifer | oai:union.ndltd.org:TORONTO/oai:tspace.library.utoronto.ca:1807/43270 |
| Date | 05 December 2013 |
| Creators | Nguyen, David |
| Contributors | Ito, Rutsuko, Erb, Suzanne |
| Source Sets | University of Toronto |
| Language | en_ca |
| Detected Language | English |
| Type | Thesis |
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