Figure 1. H₂O₂ induces an increase followed by depression in mEPSC frequency without affecting amplitude .

A, continuous chart recording of mEPSCs before, during and after H₂O₂ (1 mm) superfusion. B, average frequency (filled circles) and amplitude (open circles) of mEPSCs in the presence of H₂O₂ relative to the control, shown as a function of time (mean ± SEM, n = 11). C, summary of mEPSC frequency (left) and amplitude (right). Values are shown as percentage change in maximal values relative to the control during H₂O₂ superfusion and after washout (mean ± SEM, n = 11 each). P values were determined by a paired t test. D, cumulative distributions of the mEPSC inter‐event interval (left) and amplitude (right) before (continuous black line), during (grey line), and after (dotted line) H₂O₂ superfusion. Values were compared to the control with the Kolmogorov–Smirnov test. H₂O₂ had no effect on amplitude (during H₂O₂ superfusion: P = 0.13; after washout: P = 0.78), but inter‐event interval was shorter during H₂O₂ superfusion (P < 0.0001) and longer after washout (P < 0.0001). A and D were obtained from the same neuron. The holding potential was −70 mV for all recordings. Washout indicates the 10 min period after initiating H₂O₂ washout.