Cell coupling in the supporting cells of Corti's organ: sensitivity to intracellular H+ and Ca+2.

The input capacitance of cell pairs or small groups can be used to gauge the degree of electrical coupling via gap junctions (Santos-Sacchi, 1991). In order to estimate junctional sensitivity to intracellular Ca+2 and H+ concentration, the input capacitance of supporting cell syncytia of the organ of Corti was measured with the whole cell voltage clamp technique, while directly modifying the cation concentrations via the patch pipette. Typically, a pH below 6.5 was capable of uncoupling Hensen cells. On the other hand, pCa levels as low as 3 were ineffective.