Autaptic munc18-1 null hippocampal neurons were rescued with a phosphomimetic Munc18-1 mutant, Y473D or wild-type Munc18-1 as control and assessed on morphology and synaptic transmission using whole-cell patch clamp electrophysiology (E) Average Pves (EPSC charge / RRP charge) (M18WT: 6.75 ± 0.77%, n=13; M18Y473D: 0.24 ± 0.20%, n=10; Mann-Whitney U test, p < 0.0001). 