1: Biophys J  1991 Jan;59(1):209-20 

Membrane conductance of an electroporated cell analyzed by submicrosecond
imaging of transmembrane potential.

Hibino M, Shigemori M, Itoh H, Nagayama K, Kinosita K Jr.

Department of Physics, Faculty of Science and Technology Keio University,
Kanagawa, Japan.

Transmembrane potential was induced in a sea urchin egg by applying a
microsecond electric pulse across the cell. The potential was imaged at a
submicrosecond time resolution by staining the cell membrane with the
voltage-sensitive fluorescent dye RH292. Under moderate electric fields, the
spatial distribution of the induced potential as well as its time dependence
were in accord with the theoretical prediction in which the cell membrane was
regarded as an insulator. At higher field intensities, however, the potential
apparently did not fully develop and tended to saturate above a certain level.
The saturation is ascribed to the introduction of a large electrical
conductance, in the form of aqueous openings, in the membrane by the action of
the induced potential (electroporation). Comparison of the experimental and
theoretical potential profiles indicates that the two regions of the membrane
that opposed the electrodes acquired a high membrane conductance of the order of
1 S/cm2 within 2 microseconds from the onset of the external field. The
conductance was similar in the two regions, although permeability in the two
regions of the membrane long after the pulse treatment appeared quite different.

PMID: 2015385 [PubMed - indexed for MEDLINE]