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 (E) There is no change in the number of docked SVs per AZ length (M18WT: 14.0 ± 0.6 docked SVs/pm AZ; M18Y473D: 14.1 ± 0.9 docked SVs/pm AZ, multilevel analysis, p = 0.934). (B-E) M18WT : N=6 autaptic neurons, n=137 synapses; M18Y473D: N=8 autaptic neurons, n=116 synapses. 