Functional alterations in dopamine systems assessed using drug discrimination procedures

Numerous studies have suggested that Pb-induced perturbations of dopamine (DA) systems and DA functions could underlie the behavioral impairments attributed to Pb exposure. However, the precise nature of the effects of Pb on DA systems, either at the receptor/biochemical level or at the behavioral level have never been precisely delineated, much less interrelated. Substantial advances in the understanding of DA neuropharmacology provide new opportunities to more precisely elaborate Pb-induced changes in DA systems and DA function. Recently completed studies from our laboratories using drug discrimination procedures indicate that low-level postweaning Pb exposure produces a functional DA supersensitivity manifest at both the D1 and D2 receptor subtypes