(A–J) Immunocytochemical staining of hiPSC-derived neurons (at the time of transplantation) for classical neuronal (MAP2 and TUJ1) markers (A, B, F, and G), excitatory (TBR1 and vGlut1) markers (C, D, H, and I), and inhibitory (GABA) markers (E and J). Scale bar, 100 μm.
(K–M) Whole-cell patch-clamp recordings of iE3/3 neurons (3 weeks of maturation with astrocytes) demonstrating the capability of iE3/3 neurons to fire action potentials (K) and to receive sPSCs from both excitatory and inhibitory inputs, which were deactivated upon incubation with CNQX, APV, and gabazine, respectively (L). The average sPSC frequency was quantified from multiple iE3/3 neurons (n = 5) (M). Holding potential was −70 mV.
(N–P) Whole-cell patch-clamp recordings of E4/4 neurons (3 weeks of maturation with astrocytes) demonstrating the capability of E4/4 neurons to fire action potentials (N) and to receive sPSCs from both excitatory and inhibitory inputs, which were deactivated upon incubation with CNQX, APV, and gabazine, respectively (O). The average sPSC frequency was quantified from multiple E4/4 neurons (n = 6) (P). Holding potential was −70 mV.
(Q) Quantification of sPSC frequency recorded in iE3/3- and E4/4-hiPSC-derived neurons in vitro (iE3/3, n = 5; E4/4, n = 6).
(R) Quantification of the percentage of inhibitory sPSCs remaining after CNQX and APV wash-in, recorded in iE3/3- and E4/4-hiPSC-derived neurons in vitro (iE3/3, n = 5; E4/4, n = 6).