Human embryonic stem cells (hESC) or iPSC cultures were maintained in Essential 8 medium (Life Technologies, A1517001). Two healthy control hESC lines (H9, RUES) and two healthy control iPSC lines (J1, J2) were used in this study. The differentiation of hESCs or iPSCs (Together referred as hPSC) into CNS neurons was promoted as previously described 38 (link),39 (link). In short, for the first 10 days, the serum-free differentiation medium used consisted of Essential 6 (Life Technologies, A1516401) supplemented with 500 nM LDN189193 (Stemgent, #04–0074), 10 μM SB431542 (STEMCELL Technologies, #72232) and 5 μM XAV939 (Tocris, #3748/10). On day 10, the medium was replaced with N2 (STEMCELL Technologies, #07156), supplemented with 1:50 B-27 (Life Technologies, #12587–100), with daily replacement for eight days. The cells were then detached with Accutase (Innovative Cell Technologies, AT-104) and replated in N2 supplemented with 10 μM Y-27632 (R&D Systems, #1254) and 6 μM CHIR 99021(Tocris, #4423). Finally, after the amplification of neural progenitor cells for one or two passages, the cells were detached with Accutase, counted, and plated in wells of an appropriate size, in N2 supplemented with 10 μM Y-27632, B-27 (1:50) and 10 μM DAPT (R&D Systems, #2634/50). Neurons were left to mature for four weeks before the experiments.