Directedness, net displacement, and migration speed of neural stem cell-derived oligodendrocyte precursor cell (NSC-OPC) migration in electric fields (EFs). (A) Circular histogram. The migrated ARPC2+/+ NSC-OPCs showed clear biased distribution in EFs (200 mV/mm). It indicated the cathodal migration of the cells. The range of interval is 10 degrees. (B) Increase in average cosine (directedness) of ARPC2+/+ NSC-OPCs when field strength increased from 50 to 200 mV/mm. No change in average cosine (directedness) of ARPC2−/− NSC-OPCs in EFs from 50 to 200 mV/mm was observed. (C) More significant net cathodal displacement of ARPC2+/+ NSC-OPCs when EF increased from 50 to 200 mV/mm. No change in net displacement of ARPC2−/− NSC-OPCs when EF increased from 50 to 200 mV/mm was observed. *P <0.05, compared with ARPC2+/+ NSC-OPCs without EF stimulation. #<0.05, compared with ARPC2+/+ NSC-OPCs in EFs with field strength of 100mM/mm. (D) Analysis of cell migration speed in EFs. EFs did not significantly change migration speed of either ARPC2+/+ NSC-OPCs or ARPC2−/− NSC-OPCs. *P <0.05, compared with ARPC2−/− NSC-OPCs.