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.(E) EPSC amplitude recovery two seconds after an RRP depleting 40 Hz train. Average EPSC recovery (M18WT: 82.2 ± 6.7 %, n=17; M18Y473F: 65.5 ± 11.0 %, n=12, t-test, p = 0.1805). 