Characterization of human neurons derived from hESCs. (A) Expression of NR2B or GluR1 in human postmitotic neurons was confirmed by qRT-PCR analysis. Values are mean ± s.e.m. (B) Immunostaining of neurons at 14 DIV with anti-GluR1 antibody. Bar: 20 μm. (C) Immunostaining of neurons at 14 DIV with anti-NR2B antibody. Bars: 20 μm. (D) Membrane depolarization by 50 mM KCl treatment increased c-fos expression in hESC-derived human neurons as measured by RT-PCR analysis. Values are mean ± s.e.m. (E-H) Electrophysiological properties of human neurons derived from hESCs. Voltage-sensitive sodium and potassium currents measured in voltage-clamp (E-G) support the generation of action potentials in response to current injection (H).