Khanna S M, Hao L F
Department of Otolaryngology and Head and Neck Surgery, College of Physicians and Surgeons of Columbia University, New York, NY 10032, USA.
Hear Res. 2000 Nov;149(1-2):55-76. doi: 10.1016/s0378-5955(00)00162-3.
The apical turn of the anesthetized guinea pig cochlea was opened to examine the basilar membrane optically through the intact Reissner's membrane. Vibrations of the outer Hensen's cell and the basilar membrane (BM) adjacent to and about 130 microm below the level of the Hensen's cell were measured. Outer Hensen's cell vibration at the characteristic frequency was up to 900 times higher compared to the BM amplitude. After sacrifice BM vibration increased while Hensen's cell vibration decreased. The magnitude and sequence of change after sacrifice can best be explained by the presence of negative feedback between reticular lamina and BM. In other experiments using ototoxic drugs that damage outer hair cells, similar changes in Hensen's cell and BM vibration were observed. These results show that the apical turn behavior is different from that observed by other investigators in the basal turn. The potential benefits of the negative feedback are discussed. The presence of negative feedback would explain the linearity at the fundamental frequency observed in the apical turn of cochlea.
打开麻醉豚鼠耳蜗的顶部转弯处，通过完整的Reissner膜对基底膜进行光学检查。测量了外Hensen细胞以及与Hensen细胞水平相邻且在其下方约130微米处的基底膜（BM）的振动。在特征频率下，外Hensen细胞的振动比BM振幅高900倍。处死后，BM振动增加，而Hensen细胞振动减少。处死后变化的幅度和顺序最好用网状板和BM之间存在负反馈来解释。在其他使用损害外毛细胞的耳毒性药物的实验中，观察到Hensen细胞和BM振动有类似变化。这些结果表明，顶部转弯处的行为与其他研究者在基部转弯处观察到的不同。讨论了负反馈的潜在益处。负反馈的存在可以解释在耳蜗顶部转弯处观察到的基频线性。
