Dopamine antagonists inhibit dopamine-induced suppression of the pp fEPSP. A, Repetitive dopamine applications did not affect dopamine action on the pp fEPSP slope.B, D2 antagonist (−)eticlopride (5 μm) inhibits the effect of dopamine on the pp fEPSP slope.C, D1 antagonist (+)SCH 23390 (5 μm) inhibits the effect of dopamine on the pp fEPSP slope.D, There is no full inhibition of the effect of dopamine on the pp even by a mixture of D1 and D2 antagonists (5 μm each). E, Clozapine (20 μm) completely blocks dopamine-induced suppression of fEPSP slope in the pp. Time of drug applications is marked byrectangles.