Autaptic munc18-1 null hippocampal neurons were rescued with a phosphomimetic Munc18-1 mutant, Y473D or wild-type Munc18-1 as control and assessed on morphology and synaptic transmission using confocal microscopy (B) Average synaptic Munc18-1 intensity (M18WT: 389 ± 85 a.u., n=21; M18Y473D: 261 ± 49 a.u., n=20, t-test with Welch correction, p = 0.2000), somatic Munc18-1 intensity (M18WT: 328 ± 49 a.u., n=21; M18Y473D: 188 ± 21 a.u., n=20, t-test with Welch correction, p = 0.0138), synapse number (M18WT: 129 ± 14, n=21; M18Y473D: 159 ± 14, n=20, t-test, p = 0.1203) and dendrite length (M18WT: 0.433 ± 0.028, n=21; M18Y473D: 0.454 ± 0.037, n=20, t-test, p = 0.6613). 