ABSTRACT
For many years, gap junction channels have been considered a special category of ionic channels. One reason for this distinction was their particular localization. Instead of allowing ionic exchange between the inside and outside of the cell, they directly connect the cytoplasm of adjacent cells. Consequently, indirect calculations or direct monitoring of junctional currents require the simultaneous recording from a pair of coupled cells. This chapter introduces the double whole-cell recording technique (DWCR) and gives a general overview of the contribution to the understanding of gap junction properties. It includes a description of ways to measure junctional currents and a summary of the kinds of information that can be obtained at the macroscopic and single-channel levels. The chapter discusses the advantages and drawbacks of the technique. The patch-clamp technique was designed to study ion channel properties by isolating a small area of membrane under the pipette containing one or a few channels.
