GBR 12909 reverses the SCH 23390 inhibition of rewarding effects of brain stimulation.

Curve-shift was used to test the effect of SCH 23390, a dopamine D1 receptor antagonist, and GBR-12909, a selective dopamine uptake blocker, on self-stimulation behavior. GBR 12909 (8 mg/kg) produced a significant decrease in self-stimulation threshold when administered alone, and reversed the increase in threshold produced by SCH 23390 (0.08 mg/kg). The reversal of the SCH 23390 effect by GBR 12909 suggests that the inhibition of self-stimulation produced by SCH 23390 is due to blockade of dopamine receptors.