 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. (A) Evoked release upon action potential stimulation. Average EPSC amplitude (M18WT: 3.78 ± 0.58 nA, n=22; M18Y473F: 4.10 ± 0.61 nA, n=20, Mann-Whitney U test, p = 0.7915). Typical responses are depicted on the top. 