The HIV-1 Transactivator of Transcription (Tat) protein activates brain microglia [1] and increases brain temperature [2], both markers of neuroinflammation. Exposure to Tat protein also increases the rewarding effects of cocaine [14] and ethanol. Accordingly, we hypothesized that mice exposed to Tat protein would demonstrate elevated dopamine levels concordant with the potentiation of morphine-CPP and increased morphine consumption in a two bottle choice (TBC) assay.