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耳蜗神经的活性与基底膜运动状态的关系如何至今仍是听觉生理研究中争论的一个重要问题。本文实验试图证明基底膜位置的变化以及伴随的EP变化对CM和N_1的影响。作者们经腹外侧暴露豚鼠的耳蜗,刺激声通过装入外耳道的传声导管,同时记录在鼓膜上的声压级,用银珠电极放置在蜗窗窝缘内监测N_1;用灌入0.11M氯化钾溶液,电阻值为5～10MΩ(兆欧)的玻璃微电极经耳包囊上预先制备的小孔进入中阶,放置在离镫骨大约4mm处;另一根氯化银电极放置在上颈部肌肉作为参考电极。用110dB(SPL)的50赫连续纯音和50～70dB(SPL)的3.1千赫的短音同时刺激一耳,短音被嵌在50赫周期内的不同相位上。50赫的低频纯音使基底膜产生相应的缓慢周期性运动并伴随EP的变化,而短音引起的CM和N_1幅度将取决于短音所在50赫周期内的相位变化。实验结果表明,低频纯音可以调制CM的幅度和耳蜗神经反应N_1,在低频信号周期内,N_1常减少,仅出现两个较大的反应;
How the relationship between the activity of the cochlear nerve and the movement of the basement membrane is still an important issue in the auditory physiology research so far. This experiment attempts to demonstrate the changes in the location of the basement membrane and the accompanying changes in the EP on CM and N_1. The authors exposed guinea pig cochlea through the lateral ventricle, stimulating sound through the external auditory canal catheterization, while recording the tympanic membrane sound pressure level, silver bead electrodes placed in the wormhole margin monitoring N_1; with 0.11M Potassium chloride solution, the resistance of 5 ~ 10MΩ (megohms) glass microelectrodes through the ear capsule pre-prepared pores into the middle, placed about 4mm from the stapes; another silver chloride electrode placed In the upper neck muscles as a reference electrode. One ear is stimulated simultaneously with a 50 Hz continuous pure tone of 110 dB (SPL) and a 3.1 kHz short tone of 50-70 dB (SPL), and the short tones are embedded in different phases within a 50 Hz period. The 50 Hz low frequency pure tone causes the basement membrane to undergo a correspondingly slow periodic movement accompanied by changes in EP while the amplitude of the CM and N_1 caused by the short tone will depend on the phase change within the 50 Hz period where the short tone is located. The experimental results show that low frequency pure tone can modulate the amplitude of CM and cochlear neural response N_1, N_1 often decreases in the low frequency signal period, and only two large reactions appear.