Illustration of experimental setup for galvanotaxis assay. Neural precursor cells plated in a galvanotaxis chamber are placed in the center of the stage of a live-cell imaging system. On either side of the chamber is a Petri dish containing serum-free media (SFM) and housing the Ag/AgCl electrode. The adjacent Petri dishes and the galvanotaxis chamber are bridged via agarose gel electrodes. The Compex stimulator is connected to the Ag/AgCl electrodes to provide biphasic monopolar or biphasic bipolar stimulation. Modified with permission from Babona-Pilipos and colleagues . EFH, epidermal growth factor, basic fibroblast growth factor and heparin; FBS, fetal bovine serum.