Time course of the 5 μm PDAc-evoked enhancement of NMDA EPSCs. A, Current traces recorded at −63 mV (left) and −101 mV (right) holding potentials from an NAcc neuron before (Control) and after PDAc superfusion (10, 15, 30, and 40 min). At both potentials, PDAc enhanced the NMDA EPSC amplitudes with a maximum effect at 10 min. B, Mean (n = 7) effect of PDAc on NMDA EPSC amplitudes measured at −100 and −60 mV as a function of time. For NMDA EPSCs measured at −60 mV, the peak effect is reached 10 min after PDAc superfusion. See text for **p values. In this and subsequent figures, downward-pointingarrows in the current traces indicate the time of local stimulation to evoke EPSCs.