For electrophysiological characterization, iN cells were cocultured with mouse glia for an additional 4 to 6 weeks. Electrophysiology experiments were performed similarly to those described40. In brief, voltage-clamp recordings were performed in whole-cell configuration with internal solution containing (in mM): 135 CsCl2, 10 Hepes, 1 EGTA, 1 Na–GTP, and 1 QX-314 (pH adjusted to 7.4, 310 mOsm); whereas current-clamp internal solution contained (in mM): 130 KMeSO3, 10 NaCl, 10 HEPES, 2 MgCl2, 0.5 EGTA, 0.16 CaCl2, 4 Na2ATP, 0.4 NaGTP, and 14 Tris-creatine phosphate (pH adjusted with KOH to 7.3, 310 mOsm). The bath solution contained (in mM): 140 NaCl, 5 KCl, 2 CaCl2, 1 MgCl2, 10 glucose, and 10 HEPES-NaOH (pH 7.4).
