The Effect of the Cationic Composition in Perilymph upon the N₁ Latency of the Guinea Pig

Abstract

Although a suitable cationic composition in perilymph is known to be essential for the generation of N₁, the effect of the cationic change upon the N₁ latency has never been investigated in detail. The scala tympani was perfused with an artificial perilymph with a high K⁺, low Na⁺ or low Ca²⁺ content, with simultaneous measurement by an ion-selective microelectrode to observe its effect upon the N₁ latency. An excess of K⁺, a depletion of Na⁺ and a depletion of Ca²⁺ in perilymph individually suppressed the N₁ amplitude and elevated the N₁ threshold. The N₁ latency was not prolonged in the high K⁺ group but the significant prolongation was observed in the other two groups.

Key Words:

• N₁ latency prolongation
• cations
• perilymphatic perfusion
• ion-selective microelectrode