Supplementary Figure 1: Identification of candidate factors for the generation of inhibitory neurons.
From: Generation of pure GABAergic neurons by transcription factor programming
(a) Tuj1+ cells derived from human ES cells using different transcription factors 3 days after induction. Scale bars, 50 μm. (b) Schematic representation of the strategy to test candidate GABAergic neuron-inducing factors. (c) Example traces recorded from iN cells generated in different conditions. Left box: AMPAR-mediated spontaneous excitatory postsynaptic currents (sEPSC) recorded from an example cell (Ngn2-iN cell). Expanded view of events reveals fast kinetics (middle). Center box: GABAR-mediated spontaneous inhibitory postsynaptic currents (IPSCs, top) with slower kinetics (middle) recorded from an example cell (AM+Dlx2-iN cell). Right box: Spontaneous EPSCs with fast kinetics and spontaneous IPSCs with slower kinetics recorded from an example cell (AM+Dlx5-iN cell). (d) Representative traces of spontaneous postsynaptic currents (sPSCs) with fast kinetics as recorded from an Ngn2+EGFP-expressing neuron (red, i), or sPSCs with slow kinetics as recorded from an AM+Dlx2-expressing neuron (blue, ii), that were blocked by NBQX (50 μM, AMPAR-antagonist) or picrotoxin (50 μM, GABAAR-antagonist), respectively. Insets = expanded views of boxed areas (dotted lines). (e) Bar-graphs show the average amplitude (top panels) and τdecay (bottom panels) of sEPSCs (red) and sIPSCs (blue) in cells infected with indicated transcription-factor combinations. Bar-graphs represent mean values ± SEM (n = 5-7 cells). Filled circles represent values measured from individual cells. Asterisks (red) indicate absence of EPSC events in AM+Dlx2-expressing neurons.
