Figure 6.

Increased synaptic targeting of AMPARs accounts for enhanced AMPAR currents after reelin application. A, Representative traces of AMPAR-mediated mEPSCs recorded before and at 1 h after reelin application. CA1 neurons were voltage clamped at −65 mV. B, Reelin application significantly increases the amplitudes of mEPSCs compared with mock, as shown by the rightward shift of cumulative distribution of mEPSC amplitudes (p < 0.02; Kolmogorov–Smirnov test). C, No change of frequency distribution after reelin application was observed (p > 0.05; Kolmogorov–Smirnov test). D, Superimposed mEPSCs and their mean traces before (left; 86 mEPSCs; mean trace in thick black) and after (middle; 107 mEPSCs; mean trace in thick red) reelin were plotted. The variance traces calculated after peak scaling the mean mEPSC trace to each mEPSC trace were plotted above each panel. Right, Similar kinetics of two mean mEPSCs before and after reelin application after peak scaling. E, The mean mEPSCs were plotted against variances after binning and were fitted with the parabolic equation. Only the first 50% of data points back-calculated from the end-of-decay baseline were used to obtain the estimated number of AMPARs (N) that open during the peak of mean mEPSC and the single-channel conductance (γ). Note that N is increased after 1 h of 20 nm reelin application. In comparison, γ remains unchanged. The mean mEPSCs and variances were calculated from 165 mEPSCs before reelin application and 182 mEPSCs after reelin application. F, Pooled data on the number of AMPAR channels that open during the peak of mEPSC obtained in eight experiments. Reelin application significantly increases the number of AMPARs (**p < 0.01; paired t test).