Autaptic excitatory munc18-1 neurons expressing M18WT or M18Y473A were subjected to stimulation trains of 100 pulses at different frequencies.(C) Top: example traces of the currents evoked by 40 Hz stimulation. Bottom right: first 5 pulses of the 40 Hz train. Far right: transferred charge during 40 Hz train. Insert shows total charge transferred during entire 40 Hz train (M18WT: 2.63 ± 0.38 nC; M18Y473A: 2.93 ± 0.54 nC, t test, p = 0.6630). 