ABSTRACT
Gap junction channels span through two plasma membranes electrically and metabolically synchronizing the neighboring cells via a rapid exchange of ions and small metabolic/signaling molecules. This chapter describes two patch clamp methods to estimate the gap junction coupling conductance. There are several fundamental differences between the dye coupling and patch clamp methods. The chapter provides detailed protocols for single and dual patch clamp methods, and highlights their primary applications and limitations. Patch clamp whole-cell recording under voltage clamp configuration to record the membrane capacitance can be used for a quantitative estimation of gap junction coupling conductance in cell pairs, clusters, or confluent cells. The dual patch clamp voltage clamp method was first used to characterize gap junction properties in isolated cell pairs by Harris, Spray, and Bennett at the Einstein College of Medicine in the early 80s. The equivalent circuitry of the dual patch clamp on an isolated cell pair can be simplified.
