Generation mechanism of the negative endocochlear potential during early stage of anoxia.
To investigate the generation mechanism of the -EP in anoxic cochlea, the perilymphatic space was perfused with solution of various K+ concentrations in 38 guinea pigs when the -EP was maximally reduced by anoxia. Although the perfusion of scala tympani and vestibuli with Ringer-Locke solution or that of scala vestibuli with 154 mM K+ solution did not have any effect upon the -EP, the potential was elevated to 0 mV when the scala tympani was perfused with 154 mM K+ solution. Furthermore, the elevation of the potential was less remarkable when the K+ concentration in perfusate was reduced. The level of the potential during perfusion was closely related to K+ concentration in perfusates. The present results strongly suggest that the -EP is the result of the K+ diffusion potential and this diffusion mechanism is performed through the organ of Corti.
D000818:Animals; D003055:Cochlear Microphonic Potentials; D004058:Diffusion; D005072:Evoked Potentials, Auditory; D006168:Guinea Pigs; D000860:Hypoxia / Q000503:physiopathology*; D007552:Isotonic Solutions; D009925:Organ of Corti / Q000503:physiopathology; D010477:Perfusion; D011188:Potassium / Q000494:pharmacology; D000077331:Ringer's Solution; D012533:Scala Tympani / Q000187:drug effects / Q000503:physiopathology; D013997:Time Factors; D014722:Vestibule, Labyrinth / Q000187:drug effects / Q000503:physiopathology
D007552:Isotonic Solutions; D000077331:Ringer's Solution; D011188:Potassium