Polarization of a spherical cell in a non-uniform electric field: Transient response and comparison with polarization in a uniform field

Journal Article

Polarization of cells by extracellular fields is relevant to neural stimulation, cardiac pacing, and cardiac defibrillation. When electrodes are positioned close to cells the electric field is non-uniform, but in many cases has been assumed to be uniform. We solved analytically for the transmembrane voltage (φm) generated in a spherical cell by a non-uniform extracellular field, as would arise from a point electrode, φm reached its steady state value with a time constant much less than the membrane time constant in both uniform and non-uniform fields. The magnitude of φm in the hemisphere of the cell toward the electrode was larger than in the other hemisphere under the non-uniform field, while symmetric polarization occurred under the uniform field. The magnitude of the differences in φm generated by the uniform and non-uniform fields decreased as the distance between the cell and electrode increased, and was less than 10% for electrode to cell distances greater than 10 times the cell diameter. The specific polarization generated by a non-uniform field should be considered for small electrode to cell distances. Supported by NIH-RO1-NS-40894.

Duke Authors

Cited Authors

  • Lee, DC; Grill, WM

Published Date

  • December 1, 2002

Published In

Volume / Issue

  • 3 /

Start / End Page

  • 1980 - 1981

International Standard Serial Number (ISSN)

  • 0589-1019

Citation Source

  • Scopus