Time course of the endocochlear potential in the isolated cochlea of the guinea pig.
The temperature of Hanks' solution changed its potential (-0.48 mV/degrees C in Na(+)-Hanks' and -0.23 mV/degrees C in K(+)-Hanks' solution), but the pH had no clear effect on the potential. The time course of the endocochlear potential (EP) in the isolated cochlea of the guinea pig was measured under some different conditions. When the cochlea was moistened with Hanks' solution, negative EP increased gradually toward 0 mV at 124 min after death. When the cochlea was immersed in Hanks' solution, positive EP was obtained but it depended on the oxygen and the circulation of Hanks' solution. Moderate cooling (5 degrees C) of Hanks' solution had no significant effect on the EP of the isolated cochlea immersed in oxygen-saturated Hanks' solution circulated by oxygen bubbles. The space constant and the amplitude of the displacement responses were independent of the EP in the isolated cochlea. Thus, the positive EP might not show the physiological condition of the isolated cochlea.
Morioka
I
I
Department of Hygiene, Wakayama Medical College, Japan.
Reuter
G
G
D000818:Animals; D003051:Cochlea / Q000502:physiology; D003055:Cochlear Microphonic Potentials / Q000502:physiology*; D006168:Guinea Pigs; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D010100:Oxygen / Q000494:pharmacology; D013696:Temperature; D013997:Time Factors
D010100:Oxygen