Figure 11.

Expression of Munc18-1 P335A enhances synaptic transmission in mouse hippocampal neurons deficient of endogenous Munc18-1. Hippocampal neurons isolated from homozygous Munc18-1 floxed mice (P0–P1) were infected with the lentivirus that coexpressed GFP, WT Munc18-1-GFP, or P335A Munc18-1 GFP with Cre recombinase at DIV 3. Spontaneous EPSCs were recorded from the cultured neurons at DIV 13–15 by holding membrane potential at −70 mV. Only neurons with series resistance of ≤20 MΩ for >10 min and resting membrane potentials more negative than −50 mV were included for analysis. Spontaneous EPSCs with an amplitude of <5 pA (noise) were omitted. A, Example traces of spontaneous PSCs in the absence of stimulation. B, Cumulative probability plot of spontaneous EPSC frequency distribution from GFP, WT Munc18-1 GFP, and P335A Munc18-1 GFP. C, Average number of spontaneous EPSC events recorded per 10 s from an individual cell (gray triangle). Black squares represent means of spontaneous EPSCs in each group. Error bars indicate SEM. *p < 0.05; **p < 0.01 (one-way ANOVA, F_(2,47) = 25.99, p = 0, with Tukey's HSD post hoc test; n = 16–17/group).