Perpendicular orientation and directional migration of amphibian neural crest cells in dc electrical fields

The behavior of cultured neural crest cells of Ambystoma mexicanum and Xenopus laevis in dc electrical fields was studied. In fields of 1-5 V/cm, isolated or confluent cells retract both their anode- and cathode-facing margins. Subsequently, the cells elongate, with protrusive activity confined to their narrow ends. In larger fields (greater than or equal to 5 V/cm), protrusions form on the cathode-facing sides of the perpendicularly oriented cells. The cells then begin migrating laterally, perpendicular to their long axes, towards the cathode. We suggest that the perpendicular alignment and cathode-directed migrations result from cytoskeletal changes mediated by modified ion fluxes through the anode-facing (hyperpolarized) and cathode-facing (depolarized) cell membranes. The breaking of cellular confluence in response to dc electric fields is also discussed.