This work characterized the ability of mice to respond for conditioned reinforcement, a
phenomenon that can be used to investigate neural substrates of incentive learning. In both
C57Bl/6 and CD1 mice, a reward-associated stimulus acted as a conditioned reinforcer (CR). Responding was stable over multiple test days, enhanced in CD1 mice by the dopamine
transporter (DAT) blocker methylphenidate, and was extinguished when responding no longer produced the CR. However, transgenic C57Bl/6 mice overexpressing DAT, which decreased striatal dopamine by 40% responded normally for CR. Therefore, these results suggest that mice can be used to study brain mechanisms of incentive motivation. However, the choice of mouse strain in this paradigm is important as outbred CD1 mice appeared more susceptible to a DAT blocker compared to the inbred C57Bl/6 strain. These results also suggest that selective responding for a CR remains intact in a chronically hypodopaminergic state.
| Identifer | oai:union.ndltd.org:TORONTO/oai:tspace.library.utoronto.ca:1807/33367 |
| Date | 21 November 2012 |
| Creators | Browne, James Donald Caleb |
| Contributors | Fletcher, Paul J. |
| Source Sets | University of Toronto |
| Language | en_ca |
| Detected Language | English |
| Type | Thesis |
Page generated in 0.0016 seconds