Recent experiments with experimental animals have indicated that the behaviorally-activating action of d-amphetamine is dependent upon brain catecholamines, especially dopamine, and that brain catecholamine-using neurons are involved in the neural substrate of behavioral reinforcement. Taken together, these results are consistent with the hypothesis that the reinforcing effect involved in the self-administration of amphetamine, whether in human or animal, may occur via the drug's action on brain catecholamine systems. The proposed experiments are designed to evaluate this hypothesis by using two different techniques to map the rat brain for the anatomical sites where self-administered amphetamine exerts its reinforcing effect. In addition, the techniques should provide information concerning the neurotransmitters responsible for amphetamine reinforcement. The techniques developed in these studies should be able to be extended to the analysis of the neuroanatomical and neurochemical substrates of other self-administered drugs in the future.