Effects of AC EFs on pNPC differentiation. (A) Percentage of GFAP+/TUJ1− cells after 3, 7, and 14 DIV under control, 1 Hz, 10 Hz, and 50 Hz AC stimulation at 1 V/cm (4 h/day). (B) Percentage of GFAP–/TUJ1+ cells after 3, 7, and 14 DIV under control, 1 Hz, 10 Hz, and 50 Hz at 1 V/cm stimulation (4 h/day). (C) Percentage of GFAP+/TUJ1+ cells after 3, 7, and 14 DIV under control, 1 Hz, 10 Hz, and 50 Hz at 1 V/cm stimulation (4 h/day). (D) Comparison of the ratio of TUJ1+/GFAP+ cells after 14 DIV in the different treatment groups. (*) Significance, p<0.05.