Synaptic transmission in autaptic excitatory munc18-1 neurons expressing M18WT or a non-phosphorylatable Munc18-1 variant, M18Y473F, was tested with whole-cell patch clamp electrophysiology.(B) Average mEPSC frequency (M18WT: 5.42 ± 1.86 Hz, n=17; M18Y473F: 4.42 ± 1.01 Hz, n=14, t-test with Welch correction, p = 0.6424), mEPSC amplitude (M18WT: 20.72 ± 0.7 pA, n=17; M18Y473F: 20,5 ± 0.9 pA, n=14, t-test, p = 0.8373) and mEPSC decay time (M18WT: 2.54 ± 0.20 ms, n=17; M18Y473F: 2.46 ± 0.18 ms, n=14, t-test, p = 0.7550). Example traces of spontaneous release are depicted on top. 