Some Observations on the Origin of Anoxia-sensitive Negative EP in the Guinea Pig Cochlea

Abstract

The site responsible for the generation of the anoxia-sensitive negative potential (ASNP) observable after the administration of loop diuretics was studied in the cochlea of guinea pigs.
1. The development of ASNP was fundamentally the same, whichever perilymphatic scala was perfused with furosemide prior to the induction of anoxia.
2. Perfusion of the scala vestibuli with NaCN, which was started when the EP approached maximum negativity after the intravenous injection cf furosemide, elicited this potential even in the presence of the control perfusion in the scala tympani.
3. This potential was not inhibited by the perfusion of the scala tympani with highly oxygenated artificial perilymph which theoretically provides enough oxygenation of the organ of Corti.
4. The development of this potential was inhibited by the addition of ouabain to the perfusate with ethacrynic acid. This confirms the observations of Sellick and Johnstone.
The four findings listed above seem to indicate that the site responsible for the generation of ASNP is the stria vascularis rather than the organ of corti.