(B-G) Munc18-1 null hippocampal neurons were rescued with wildtype Munc18-1a or a Munc18-1 mutant, Y473A, in which Y473 was replaced with alanine.(D) Evoked release upon action potential stimulation. Average EPSC amplitude (M18WT: 7.96 ± 0.94 nA, n=30; M18Y473A: 1.44 ± 0.34 nA, n=33, t-test with Welch correction, p < 0.0001). Typical responses are depicted on the right. 