稳态白噪声对豚鼠耳蜗电位影响的研究

EFFECTS OF WHITE NOISE ON COCHLEAR POTENTIALS IN GUINEA PIGS

本工作利用面神经管慢性埋植电极在清醒动物上对噪声暴露前后听神经动作电位(AP)和微音器电位(CM) 进行了研究,结果表明:当改变测试声强和频率时CM应起始点会发生移位(CM-shift); 123dBSPL稳态白噪声暴露1小时后.AP各参数(幅值、潜伏期和阈值)均发生明显变化.而CM各参数(幅值、CM-shift和检测阈)变化则基本未达显著性.说明AP对产损伤的敏感性要高于CM另外发现噪声暴露后AP的N_2峰的恢复比N_1峰快、CM在恢复过程中会出现幅值加大现象.

Changes in cochlear microphonics(CM) and auditory nerve action potential(AP) after exposure to noise were investigated in guinea pigs. Chronically implanted eletrodes were used to record CM and AP in awake animals after being exposed to white noise at 123dB SPL intensity. The rising point of CM shifted to the different frequencies and intensities from test stimuli. The sensitivities of AP(amplitude. latency and threshold) to noise exposure were greater than that of CM(amplitude. CM-shift and detected threshold). Recovery of AP-N2 amplitude was quicker than AP -N1. and CM amplitude increased in a short time after exposure. The relationship between AP and CM changes and the mechanism of CM-shift were discussed.