Spontaneous EPSCs were not affected by PDC.A, The membrane current was recorded continuously (4 sec records are displayed) from a GLC voltage-clamped at −80 mV. Spontaneous EPSCs were clearly observed. The slice preparation was superfused with the solution containing d-AP-5 (50 μm; Control) and then with the solution containing d-AP-5 and PDC (200 μm).B, The cumulative amplitude distribution of spontaneous EPSCs obtained in the absence (thick line) and presence (thin line) of PDC. C, The waveforms of the averaged spontaneous EPSCs in the absence (thick line) and presence (thin line) of PDC.D, Relative changes of the peak amplitude and total charge of the averaged spontaneous EPSCs in the absence and presence of PDC (n = 5). The averaged values of five data are shown by large filled circles. E, The decay phase of the averaged spontaneous EPSC was well fitted by a single exponential function. The time constant of the decay (τdecay) was not affected by PDC. Data were obtained from five cells.