Ionic Conductance Change in Supporting Cells of the Organ of Corti Caused by Ca2+
The supporting cells of the organ of Corti are considered to buffer and support the hair cells. Recent technical advances in experiments concerning the inner ear have indicated that these cells play a physiological role in the inner ear. It has also been found that conductance of the gap junction between supporting cells is regulated by Ca2+ and H+. Therefore, it is suggested that Ca2+ regulates ionic conductance of the supporting cells. In the present study, 10 μM A23187, 10 μM IP3 and 10 mM BAPTA, were applied extracellularly and intracellularly. Outward current was increased by 10 μM A23187, 10 μM IP3, but decreased by 10 mM BAPTA. When Cl- was replaced with sodium gluconate, the outward current decreased. Therefore, it was concluded that Ca2+ regulates the ionic conductance of the supporting cells of the organ of Corti, and it is suggested that Ca2+ maintains outward current.