Potassium Currents in Isolated Deiters' Cells of Guinea Pig

Abstract

Deiters' cells are the supporting cells in organ of Corti and are suggested to play an important role in biochemical and mechanical modulation of outer hair cells. We successfully isolated functionally different K+ currents from Deiters' cells of guinea pig using whole cell patch clamp technique. With high K+ pipette solution, depolarizing step pulses activated strongly outward rectifying currents which were dose-dependently blocked by clofilium, a class III anti-arrhythmic K+ channel blocker. The remaining outward current was transient in time course whereas the clofilium-sensitive outward current showed slow inactivation and delayed rectification. Addition of 5 mM tetraethylammonium (TEA) further blocked the remaining current leaving a very fast inactivating transient outward current. Therefore, at least three different types of K+ current were identified in Deiters' cells, such as fast activating and fast inactivating current, fast activating slow inactivating current, and very fast inactivating transient outward current. Physiological role of them needs to be established.

Active role of glia‐like supporting cells in the organ of Corti: Membrane proteins and their roles in hearing

“…A Ca 2+ -independent outward rectifying K + current by Kv1.5 has been suggested to restore the resting potential of cells after depolarization (Nenov et al, 1998). Similarly, Kv1.4 and Kv3.4 have been shown to be involved in precise and complex modulation of the K + circuitry of DCs (Chung et al, 2013) (Table 2, Figure 3d). These outwardly rectifying potassium channels in DCs are speculated to buffer extracellular K + in the small space between DCs and OHCs or neural fibers and participate in K + diffusion from the endolymph to the perilymph (Yang & Wang, 2002) (Figure 3d).…”

“…Isolated DCs have been found to possess a large voltage‐dependent outwardly rectifying K + conductance (Chung et al, 2013; Nenov et al, 1998). A Ca 2+ ‐independent outward rectifying K + current by Kv1.5 has been suggested to restore the resting potential of cells after depolarization (Nenov et al, 1998).…”