Previous research has demonstrated that rats reared in an enriched condition (EC) with novel objects and social partners self-administer less amphetamine compared to rats raised in an isolated condition (IC). However, it is unclear if the enrichment-induced decrease in stimulant self-administration generalizes to non-drug rewards such as those provided by novel environmental stimuli. In the current study, EC, IC, and social condition (SC) rats were raised from 21 to 51 days of age before being tested in a two-lever operant conditioning chamber in which responding on one lever (active lever) resulted in illumination of a cue light. In Experiment 1, rats were initially assessed for baseline responding (no contingency) and then the contingent light was introduced. EC rats responded less than IC rats for the contingent light stimulus; however, EC rats also displayed a lower rate of baseline responding. In Experiment 2, rats were trained initially to lever press for a sucrose reward to decrease differences in baseline responding. While sucrose pretraining decreased baseline response differences between groups, EC rats still responded less for the contingent light stimulus than IC or SC rats. These results suggest that environmental enrichment decreases the incentive value of visual novelty.
|Number of pages||7|
|State||Published - Nov 1 2006|
Bibliographical noteFunding Information:
Research was funded by USPHS Grant R01 DA12964. MEC supported by USPHS Grant F32 DA16013 and T.A.G. supported by USPHS Grant F31 DA06093. The authors would like to thank Kathryn Bylica, Laura Fenton, and Brenna Shortridge for their assistance with this project, and Dr. Rick Bevins for some helpful discussion regarding the work.
ASJC Scopus subject areas
- Animal Science and Zoology
- Behavioral Neuroscience