豚鼠耳蜗神经活动的频谱特征

目的了解清醒状态下豚鼠耳蜗神经电生理活动的平均功率谱（Ａｖｅｒａｇｅｓｐｅｃｔｒｕｍｏｆｅｌｅｃｔｒｏｐｈｙｓｉｏｌｏｇｉｃａｌｃｏｃｈｌｅｏｎｅｕｒａｌａｃｔｉｖｉｔｙ，ＡＳＥＣＡ）的正常特征及观察耳蜗不同状况下ＡＳＥＣＡ的变化。方法采用园窗慢性电极记录耳蜗神经电活动，通过ＦＦＴ变换获得ＡＳＥＣＡ。结果在安静条件清醒状态下豚鼠ＡＳＥＣＡ图为在低频１００Ｈｚ附近有一最大的能量峰，紧接着靠近５００Ｈｚ处的为一谱谷以及中心频率为１ｋＨｚ的宽谱峰（ＡＳＥＣＡ—１ｋＨｚ）。镇静剂、麻醉剂及电极植入手术均对ＡＳＥＣＡ产生影响。结论本研究表明ＡＳＥＣＡ１ｋＨｚ为ＡＳＥＣＡ的正常特征，且３６ｄＢ（ｒｅ１ｎＶ）为ＡＳＥＣＡ１ｋＨｚ幅值的正常低限值。

Average Spectrum of Electrophysiological Cochleoneural Activity in Guinea Pig

Objective To investigate the spectral features of average spectrum of electrophysiological cochleoneural activity(ASECA) recorded from the round window,and to observe the alteration of ASECA under sedation,anesthesia and operation. Method The recording of electrophysiological cochleoneural activity was to implant an electrode at the round window, the ASECA was obtained to FFT transform for the signal recorded.FZResult The pattern of in silent conditions from awake guinea pigs exhibited a similar pattern from all animals with a first peak of maximal energy at the lowest frequencies up to 100 Hz followed by a valley near 500 Hz and a broad peak centered 1 kHz. We found that the valley 500 Hz was deepened and not shifted, and that the CAP threshold was not increased under sedation and anesthesia with maintenance of temperature. But we found also that the valley 500 Hz was towards 400 Hz and deepened, and the ASECA-1kHz was shifted towards 0.8 kHz and decreased under sedation and anesthesia with decreasing temperature. Conclusion Our study shows that ASECA-1 kHz is the spectral feature of ASECA,and that the minimum normal value of ASECA-1 kHz is 36 dB(re 1nv).