Neurons expressing M18Y473D are not impaired at SV docking. Autaptic munc18-1 null hippocampal neurons expressing M18Y473D or M18WT as controls were analysed with electron microscopy on chemically fixed samples ((C) Total number of SVs is not different (M18WT: 142 ± 11 SVs; M18Y473D: 148 ± 15 SVs, multilevel analysis, p = 0.456).(B-E) M18WT : N=6 autaptic neurons, n=137 synapses; M18Y473D: N=8 autaptic neurons, n=116 synapses. 