Differential expression of outer hair cell potassium currents in the isolated cochlea of the guinea-pig

2. Two major potassium currents were expressed in the cells. One current, named I,, was half-activated at -24 mV and was most prominent in the most apical turn, turn 4. A second, named I-K,(n) was half-activated at -92 mV and was the major contributor to the current-voltage (I-V) curve of cells from the more basal turns, turns 3 and 2, of the cochlea.

1. Whole-cell currents were recorded from outer hair cells (OHCs) in undissociated tissues from the organ of Corti. The experiments allowed ionic currents to be measured in cells with precise localization on the three most apical cochlear turns.