Fig. 8. Depletion of [Ca²⁺]_e abolishes electrotactic response. (A,C) Varying [Ca²⁺]_e concentrations did not affect cell migration in control conditions. (B) Increasing [Ca²⁺]_e to 0.6 mM did not affect the electrotactic response. (D) depletion of [Ca²⁺]_e (by using Ca²⁺-free buffer or addition of 5 mM EGTA) completely abolished the electrotactic response, while the cells still migrate actively. (supplementary material, Movie 4). Numbers in A-D indicate individual cells.