SCZD and control hiPSCs were derived and characterized as previously described (Brennand et al., 2011). hiPSC colonies were kept in feeder-free conditions and passed using mechanical dissociation. EBs were formed by mechanical dissociation of hiPSC colonies using collagenase and plating onto low-adherence dishes in hESC medium without fibroblast growth factor 2 (FGF2). For EB differentiation, floating EBs were treated with DKK1 (0.5 μg/ml), SB431542 (10 μM), Noggin (0.5 μg/ml), and cyclopamine (1 μM) in Dulbecco’s modified Eagle’s medium (DMEM)/F12 (Invitrogen) plus N2 and B27 for 20 days followed by Wnt3a (20 ng/ml) and BDNF (20 ng/ml) in DMEM/F12 plus N2 and B27 for 20 days. The EBs were dissociated with Papain and DNase (Worthington) for 1 hr at 37°C and plated onto a monolayer of human hippocampal astrocytes (ScienCell). To obtain NPCs, EBs treated with DKK1/SB431542/Noggin/cyclopamine were plated after 20 days onto polyornithine/laminin (Sigma)-coated dishes in DMEM/F12 (Invitrogen) plus N2. Rosettes were manually collected and dissociated with Accutase (Chemicon) after 1 week and plated onto coated dishes with NPC media (DMEM/F12, N2, B27, and FGF2). To obtain mature neurons, NPCs
