Figure 3Neurons 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 (A) Typical electron microscopy images from both groups. Scale bar = 100nm. 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 (B) Average number of docked SV (M18WT: 7.63 ± 0.15 SVs; M18Y473D: 8.45 ± 0.20 docked SVs, multilevel analysis, p = 0.047).(B-E) M18WT : N=6 autaptic neurons, n=137 synapses; M18Y473D: N=8 autaptic neurons, n=116 synapses. 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. 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 (D) The active zone (AZ) length is similar (M18WT: 561 ± 24 nm; M18Y473D: 646 ± 59 nm, multilevel analysis, p = 0.161).(B-E) M18WT : N=6 autaptic neurons, n=137 synapses; M18Y473D: N=8 autaptic neurons, n=116 synapses. 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. 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 (F) Typical electron microscopy images from both groups. Scale bar = 200nm. 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 (G) Average number of docked SV is equal (M18WT: 10.17 ± 0.38 SVs; M18Y473D: 10.75 ± 0.40 docked SVs, multilevel analysis, p = 0.264).(G-J) M18WT : N=3 independent cultures, n=159 synapses; M18Y473D: N=3 independent cultures, n=156 synapses. 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 (H) Total number of SVs is similar (M18WT: 160.2 ± 9.7 SVs; M18Y473D: 176.7 ± 9.2 SVs, multilevel analysis, p = 0.212).(G-J) M18WT : N=3 independent cultures, n=159 synapses; M18Y473D: N=3 independent cultures, n=156 synapses. 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 (I) The active zone (AZ) length is similar (M18WT: 740.2 ± 29.7 nm; M18Y473D: 771.4 ± 28.1 nm, multilevel analysis, p = 0.871).(G-J) M18WT : N=3 independent cultures, n=159 synapses; M18Y473D: N=3 independent cultures, n=156 synapses. 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.