Assessment of cocaine-like discriminative stimulus effects of dopamine D 3 receptor ligands

Abstract

The highly selective dopamine D 3 receptor ligand, (+)-PD 128907 4 aR10 bR-(+)- trans-3,4,4 a,10 b-tetrahydro-4- n-propyl-2H5 H[4,3- b]-1,4-oxazin-9-ol), and other dopamine D 3 receptor ligands, (±)-7-hydroxy-2-( N,N-di- n-propylamino)tetralin and (+)-7-hydroxy-2-( N,N-di- n-propylamino)tetralin, substituted for the discriminative stimulus effects of cocaine in rats, an animal model of subjective effects in humans. Substitution only occurred at doses that markedly decreased responding. These results suggest that dopamine D 3 receptors may be involved in the subjective effects of cocaine, and therefore may be a target for the discovery of treatments for cocaine dependence.