Direct Demonstration of Dielectric Breakdown in the Membranes of Valonia utricularis

Abstract

It is shown that if the membrane potential of cells of Valonia utricularis was increased rapidly by applying ~500 μs current pulses, dielectric breakdown of the membrane occured when the potential reached a value of ~0.85 V. The breakdown phenomenon observed was not associated with global damage to the cell or its membrane. The process could be repeated after a short resealing time (~ 10s), many times on a single cell. The rapidity of the breakdown process (~1 μs) rules out the possibility that dielectric breakdown occurs by a mechanism similar to that of punch-through, which involves changes in ionic profiles.