Autaptic excitatory munc18-1 neurons expressing M18WT or M18Y473A were subjected to stimulation trains of 100 pulses at different frequencies.(D) EPSC augmentation is calculated by dividing the EPSC amplitude of a single pulse after a stimulation train by the amplitude of the first EPSC within this train. Mean augmentation after 5 Hz train (M18WT: 0.54 ± 0.05, n=8; M18Y473A: 2.88 ± 0.47, n=10; Unpaired t-test with Welch correction, p = 0.0008), 10 Hz train (M18WT: 0.70 ± 0.10, n=8; M18Y473A: 5.39 ± 0.77, n=10; Unpaired t-test with Welch correction, p = 0.0002) and 40 Hz train (M18WT: 0.93 ± 0.11, n=8; M18Y473A: 8.77 ± 1.52, n=10; Unpaired t-test with Welch correction, p = 0.0006). 