Title

Effects of Acute Pramipexole on Preference for Gambling-Like Schedules of Reinforcement in Rats

Document Type

Article

Journal/Book Title/Conference

Psychopharmacology

Volume

213

Issue

1

Publisher

Springer Verlag

Publication Date

2010

First Page

11

Last Page

18

DOI

10.1007/s00213-010-2006-5

Abstract

Rationale

Pramipexole and other direct dopamine agonist medications have been implicated in the development of impulsive behavior such as pathological gambling among those taking the drug to control symptoms of Parkinson’s disease or restless leg syndrome. Few laboratory studies examining pramipexole’s effects on gambling-like behavior have been conducted.

Objectives

The present study used a rodent model approximating some aspects of human gambling to examine within-subject effects of acute pramipexole (0.03, 0.1, 0.18, and 0.3 mg/kg) on rat’s choices to earn food reinforcement by completing variable-ratio (VR; i.e., gambling-like) or fixed-ratio (FR) response requirements.

Results

In a condition in which the VR alternative was rarely selected, all but the lowest dose of pramipexole significantly increased choice of the VR alternative (an average of 15% above saline). The same doses did not affect choice significantly in a control condition designed to evaluate the involvement of nonspecific drug effects. Pramipexole increased latencies to initiate trials (+9.12 s) and to begin response runs on forced-choice trials (VR = +0.21 s; FR = +0.88 s), but did not affect measures of response perseveration (conditional probabilities of “staying”).

Conclusions

The findings are consistent with clinical reports linking pramipexole to the expression of increased gambling in humans. Results are discussed in the context of neurobehavioral evidence suggesting that dopamine agonists increase sensitivity to reward delay and disrupt appropriate feedback from negative outcomes.

Comments

Originally published by Springer Verlag. Publisher's PDF and HTML fulltext available through remote link.
Note: Gregory Madden was affiliated with the University of Kansas at time of publication.