mEPSCs recorded in the insular cortex during neuropathic pain. A, Representative mEPSCs recorded in the insular cortical neuron in slices from sham mice (top) and mice with nerve ligation (bottom) at a holding potential of −70 mV. Cumulative interevent interval (left) and amplitude (right) histograms of mEPSCs recorded in slices from sham mice (line) and mice with nerve ligation (dotted line). B, Summary plots of mEPSC data. Averaged values of mEPSC parameters: mean amplitude (left, n = 13 neurons for sham and n = 19 neurons for nerve ligation) and mean peak frequency (right, n = 11 neurons for both groups). C, Representative traces with an interval of 50 ms recorded in layer II/III of the insular cortex. Paired-pulse ratios (the ratio of EPSC2/EPSC1) were recorded at intervals of 35, 50, 75, 100, and 150 ms from sham and nerve-ligated mice. Open circles, Neurons from sham mice (n = 6 neurons); filled circles, neurons from mice with nerve ligation (n = 11 neurons). *p < 0.05 compared with sham control (two-way ANOVA).