The purpose of this contract will be to provide testing capacity in the following rodent in vivo assays: mouse locomotor activity, rat drug discrimination, mouse conditioned place preference, and rat self-administration. These models are part of a larger pre-clinical testing hierarchy supported by separate contracts that fund the evaluation of compounds in the rat intracranial self-stimulation assay, various models of relapse to drug-seeking behavior, as well as the primate drug discrimination and self-administration models.