Warren Rebecca L, Ramamoorthy Sripriya, Ciganović Nikola, Zhang Yuan, Wilson Teresa M, Petrie Tracy, Wang Ruikang K, Jacques Steven L, Reichenbach Tobias, Nuttall Alfred L, Fridberger Anders
Department of Clinical and Experimental Medicine, Linköping University, SE-58183 Linköping, Sweden;
Department of Mechanical Engineering, Indian Institute of Technology Bombay, Mumbai, Maharashtra 400076, India;
Proc Natl Acad Sci U S A. 2016 Jul 26;113(30):E4304-10. doi: 10.1073/pnas.1606317113. Epub 2016 Jul 12.
Low-frequency hearing is critically important for speech and music perception, but no mechanical measurements have previously been available from inner ears with intact low-frequency parts. These regions of the cochlea may function in ways different from the extensively studied high-frequency regions, where the sensory outer hair cells produce force that greatly increases the sound-evoked vibrations of the basilar membrane. We used laser interferometry in vitro and optical coherence tomography in vivo to study the low-frequency part of the guinea pig cochlea, and found that sound stimulation caused motion of a minimal portion of the basilar membrane. Outside the region of peak movement, an exponential decline in motion amplitude occurred across the basilar membrane. The moving region had different dependence on stimulus frequency than the vibrations measured near the mechanosensitive stereocilia. This behavior differs substantially from the behavior found in the extensively studied high-frequency regions of the cochlea.
低频听力对于语音和音乐感知至关重要，但此前尚未有针对低频部分完整的内耳进行的机械测量。耳蜗的这些区域可能以与广泛研究的高频区域不同的方式发挥作用，在高频区域，感觉性外毛细胞产生的力极大地增加了基底膜的声诱发振动。我们使用体外激光干涉测量法和体内光学相干断层扫描技术来研究豚鼠耳蜗的低频部分，发现声音刺激导致基底膜的一小部分发生运动。在峰值运动区域之外，基底膜上的运动幅度呈指数下降。与在机械敏感的静纤毛附近测量的振动相比，运动区域对刺激频率的依赖性不同。这种行为与在耳蜗广泛研究的高频区域中发现的行为有很大不同。
