FIG. 9.

Voltage-gated Ca²⁺ currents and spontaneous synaptic activity in the developing neurons. (A) In a 3-week hiPS cell-derived neuron, the high-voltage-activated (HVA) Ca²⁺ currents were evoked by voltage steps from −60 to +60 mV in presence of TTX, Cs⁺, and TEA. 100 μM CdCl₂ was used to inhibit HVA Ca²⁺ currents. (B) The I/V relationship curve of HVA Ca²⁺ currents before and after application of CdCl₂. (C) The amplitude of HVA Ca²⁺ currents in differentiating neurons derived from hiPS cells. (D) HVA Ca²⁺ currents in differentiating neurons derived from human ES cells. (E) Miniature excitatory and inhibitory postsynaptic currents (mE/IPSCs) were recorded at holding potentials of −80 and 0 mV, respectively. α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor antagonist NBQX (20 μM) and gamma-aminobutyric acid (GABA) receptor antagonist bicuculline (50 μM) were used to suppress mE/IPSCs. *P<0.05, comparing the correlated groups as indicated. n=5–8 in each group.