The present study was designed to evaluate the effects of a moderate dose of ethanol (1 g/kg) on dopamine (DA) dynamics in rat nucleus accumbens (NAc) using fast-scan cyclic voltammetry. Voltammetric recordings were made every 100 ms at a carbon fiber microelectrode, positioned in the NAc core. Acute ethanol did not significantly alter DA uptake parameters (K(m) and V(max)), but amplitudes of the DA signals were decreased after the drug in both freely moving and anesthetized rats. Therefore, the present in vivo voltammetry results suggest that DA uptake changes are not involved in ethanol-induced increases in extracellular DA concentrations.