“…Relatively few electrical measurements have been made on isolated cells, because the transmembrane voltage, U(t) y measurement requires the use of either microelectrodes (Benz and Zimmermann, 1980) or voltage-sensitive dyes (Kinosita et al, 1988;Farkas, 1989;Kinosita et al, Chapter 3, this volume). Alternatively, measurement across a monolayer tissue (e.g., frog skin) reflects the average transcellular electrical behavior of a large number of cells (Stämfli, 1958;Fishman and Macey, 1969;Benz and Conti, 1981;Powell et al, 1989).…”