title: Spinal neurite reabsorption and regrowth in vitro depend on the polarity of an applied electric field.
abstract: Retraction and regrowth of frog neural tube neurites have been studied in vitro in control cultures and in the presence of a small, continuously applied electrical field. In control cultures, some degree of retraction was seen in 39% of neurites while 7% were reabsorbed completely. Reabsorption of anodal-facing neurites was at least twice as common, with 67% showing some retraction and 17% almost totally reabsorbed. Cathodal-facing neurites were spared from retraction. Following extreme reabsorption of anodal-facing neurites, reversal of the electric field promoted regeneration in 47% (9/19) of cases studied. growth cone morphology also was determined by the polarity of the applied field. Anodal-facing growth cones had fewer filopodia than cathodal-facing growth cones sharing the same cell body. Field reversal induced a polarity-specific change in filopodia number on individual growth cones: a shift from anodal to cathodal increased filopodia numbers and vice versa. Some possible mechanisms involved and the significance of these results are discussed.
mesh_terms: D000818:Animals; D001369:Axons / Q000502:physiology* / Q000648:ultrastructure; D002478:Cells, Cultured; D004560:Electricity; D009410:Nerve Degeneration; D009416:Nerve Regeneration; D010781:Photography; D013116:Spinal Cord / Q000502:physiology*; D013997:Time Factors; D014982:Xenopus laevis