ASSESSMENT OF COCAINE-LIKE DISCRIMINATIVE STIMULUS EFFECTS OF DOPAMINE D-3 RECEPTOR LIGANDS

The highly selective dopamine D-3 receptor ligand, (+)-PD 128907 aR10b R-(+)-trans-3,4,4a,10b-tetrahydro-4-n-propyl- 2H5H[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)te tralin, substituted for the discriminative stimulus effects of cocaine in rats, an animal model of subjective effects in humans. Substitutio n only occurred at doses that markedly decreased responding. These res ults suggest that dopamine D-3 receptors may be involved in the subjec tive effects of cocaine, and therefore may be a target for the discove ry of treatments for cocaine dependence.