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 cryofixed samples ( (J) There is no change in the number of docked SVs per AZ length (M18WT: 14.36 ± 0.32 docked SVs/pm AZ; M18Y473D: 14.34 ± 0.32 docked SVs/pm AZ, multilevel analysis, p = 0.969). (G-J) M18WT : N=3 independent cultures, n=159 synapses; M18Y473D: N=3 independent cultures, n=156 synapses. 