白噪声暴露后豚鼠耳蜗两音抑制现象的实验观察

基金项目:

国家自然科学基金资助项目

详细信息

Effects of white-noise on two-tone suppressions in AC receptor potentials of guinea pigs

摘要: 本实验用玻璃微电极的方法记录了白噪声暴露前后,在单音和两音刺激声作用下豚鼠耳蜗第三回中阶交流感受器电位的变化,并用园窗电极引导的CAP阈值监测声损伤程度.比较单音和两音诱发的CM幅度发现:两音抑制与耳蜗的非线性特性密切相关,均依赖于耳蜗的正常生理环境;外毛细胞的双向换能作用是耳蜗非线性机械特性和两音抑制存在的前题。本实验还对中耳和刺激声谐波产生两音抑制的可能性给予排除,并介绍了实验中所用的计算机程控刺激、记录分析系统和用快速傅里叶变换(FFT)测量不同频率分量的方法。

Abstract: Two-tone suppression (2TS) was studied in AC receptor potentials recorded from scale media in the third turn of guinea pig cochlea. Electrode of round window was used to monitor the CAP threshold. Amplitude-intensity functions for AC component were obtained before and after white-noise exposure. Results indicated that the phenomenon of 2TS wasrelated with nonlinearity of cochlea, and suppressed amplitude decreased with diminish of these high-level nonlinearities. The probability that 2TS caused by media ear and homophonic was diminished. A computer controlled sound stimulator and signal recording system was used in the study, in which FFT was also used to calculate the amplitude of receptor potentials.