Rybak L P, Whitworth C, Scott V
Department of Surgery, Southern Illinois University School of Medicine, Springfield 62794-9230.
Hear Res. 1992 May;59(2):189-94. doi: 10.1016/0378-5955(92)90115-4.
The present study was designed to investigate the developmental changes of the endocochlear potential and compound action potential simultaneously from rat pups of various ages. Animals were anesthetized with ketamine/xylazine, and the endocochlear potential was measured with a glass microelectrode. At the same time, a wire electrode was placed on the round window to record the click-evoked compound action potential. The endocochlear potential was found to be very low during the first few days of postnatal life. A rapid increase in the value of the endocochlear potential was noted between eleven and thirteen days of age, and adult-like values were recorded by seventeen days of age. Compound action potential responses were recorded at thirteen days of age to high intensity clicks, followed by a progressive improvement of thresholds and reduction of latencies. The development of the endocochlear potential and compound action potential was found to be reciprocally related - as the magnitude of the endocochlear potential increased, the compound action potential threshold declined with increasing age. The development of the endocochlear potential was found to closely approximate the development of enzymatic activity of sodium, potassium-ATPase in the stria vascularis reported by Kuijpers (1974).
本研究旨在同时研究不同年龄大鼠幼崽的内耳蜗电位和复合动作电位的发育变化。动物用氯胺酮/赛拉嗪麻醉，并用玻璃微电极测量内耳蜗电位。同时，将线状电极置于圆窗上记录短声诱发的复合动作电位。发现出生后最初几天内耳蜗电位非常低。在内耳蜗电位值在11至13日龄之间迅速增加，到17日龄时记录到类似成年动物的值。在13日龄时记录到高强度短声诱发的复合动作电位反应，随后阈值逐渐改善，潜伏期缩短。发现内耳蜗电位和复合动作电位的发育呈负相关——随着内耳蜗电位幅度增加，复合动作电位阈值随年龄增长而下降。发现内耳蜗电位的发育与Kuijpers（1974年）报道的血管纹中钠钾ATP酶的酶活性发育密切相似。
