Effects of DBH inhibition on extracellular DA levels in the NAc of unanesthetized squirrel monkeys administered disulfiram (10 mg/kg) 30 minutes prior to cocaine (1.0 mg/kg) (N = 3) (A) or nepicastat (10 mg/kg) 30 minutes prior to cocaine (1.0 mg/kg) (N = 4) (B). Data points (mean ± S.E.M.) are expressed as the percentage of baseline DA levels before drug administration. *P < 0.01; **P < 0.001, compared with vehicle control. Coc, cocaine; Dis, disulfiram; Nep, nepicastat; Veh, vehicle.