QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: jpet.105.100339v1 317/3/1178    most recent Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Sellings, L. H. L. Articles by Clarke, P. B. S. Search for Related Content PubMed PubMed Citation Articles by Sellings, L. H. L. Articles by Clarke, P. B. S.

BEHAVIORAL PHARMACOLOGY

Evidence for Multiple Sites within Rat Ventral Striatum Mediating Cocaine-Conditioned Place Preference and Locomotor Activation

Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada

Considerable evidence suggests that psychostimulants can exert rewarding and locomotor-stimulating effects via increased dopamine transmission in the ventral striatum. However, the relative contributions of ventral striatal subregions to each of these effects have been little investigated. In the present study, we examined the contribution of different ventral striatal sites to the rewarding and locomotor-activating effects of cocaine. Initially, the effects of bilateral 6-hydroxydopamine lesions of the nucleus accumbens core or medial shell on cocaine-induced locomotor stimulation (0.5–1.5 mg/kg i.v. or 5–20 mg/kg i.p.) and conditioned place preference (0.5 mg/kg i.v. or 10 mg/kg i.p.) were examined. In a subsequent study, we investigated the effects of olfactory tubercle versus medial shell lesions on cocaine-conditioned place preference and locomotor activity (0.5 mg/kg i.v.). Dopaminergic lesion extent was quantified by radioligand binding to the dopamine transporter. Multiple linear regression was used to identify associations between behavioral effects and residual dopamine innervation in ventral striatal subregions. On this basis, the accumbens core was associated with the locomotor stimulant effects of i.v. and i.p. cocaine. In contrast, the medial shell was associated with the rewarding effect of i.v. cocaine, but not of i.p. cocaine. Finally, the olfactory tubercle was identified as an additional site contributing to conditioned place preference produced by i.v. cocaine. Overall, these findings provide additional evidence that the locomotor stimulant and rewarding effects of systemically administered psychomotor stimulant drugs are segregated within the ventral striatum.

Address correspondence to: Dr. Paul B. S. Clarke, 3655 Promenade Sir-William-Osler Room 1325, Montreal, QC, Canada H3G 1Y6. E-mail: paul.clarke{at}mcgill.ca