Changes in endocochlear potential, cochlear microphonics, compound action potential and the morphology of Hair cells in guinea pig during acute anoxia

Endocochlear Potential (EP), Cochlear Microphonics (CM), Compound Action Potential(CAP) were recorded from scala media of guinea pig's cochlear the second turn with the same microelectrode,CM and CAP droped rapidly with EP in 1-2 minute in anoxia. In 3-6 minutes, CM droped slowly, forming a platform. While CAP and EP droped continuously. In 7-12 minutes CM droped in parallel with CAP and EP. Scanning electronic microscope declare:the mild damage of the spiral organ due to anoxia. The secretive and global substance on the inner hair cell's (IHC) surface are observed. The defined secretion of global substance on outer hair cells (OHC) and fusedstereocilia are also seen. The results show f the function of OHC and IHC are related with metabolism of Oxygen. The change in CM was affected directly by OHC and IHC damage. CM platform in anoxia is probably related with the piezoelectric effect of tectorial membrance.