Transient Aqueous Pores: A Mechanism for Coupling Electric Fields to Bilayer and Cell Membranes

Abstract

The purpose of this chapter is to describe the basic concepts underlying the interaction of electric fields with hypothetical transient aqueous pores in bilayer membranes. The motivation for this theory is the explanation of several dramatic, high field phenomena which occur in artificial bilayer and cell membranes. A basic hypothesis is that transient aqueous pores can be present because of thermal fluctuations. First the relation between applied fields and the resulting changes in transmembrane potential, a transduction process, is described. Because the signal-to-noise ratio is important to understanding any transduction, an estimate of fundamental fluctuations in the transmembrane potential is considered, and found not to be limiting. The high field transient aqueous pore theory is then reviewed, with an emphasis on the electrical coupling to bilayer membranes by means of pores. Finally, the ability of the present theory to quantitatively describe several dramatic high field phenomena is discussed, possible weak field interactions are identified, and some of the limitations of the present theory are noted.