NIDCD, National Institutes of Health, Bethesda, MD 20892, USA.
Hear Res. 2022 Sep 15;423:108422. doi: 10.1016/j.heares.2021.108422. Epub 2021 Dec 17.
Avian hair cells depend on electrical resonance for frequency selectivity. The upper bound of the frequency range is limited by the RC time constant of hair cells because the sharpness of tuning requires that the resonance frequency must be lower than the RC roll-off frequency. In contrast, tuned mechanical vibration of the inner ear is the basis of frequency selectivity of the mammalian ear. This mechanical vibration is supported by outer hair cells (OHC) with their electromotility (or piezoelectricity), which is driven by the receptor potential. Thus, it is also subjected to the RC time constant problem. Association of OHCs with a system with mechanical resonance leads to piezoelectric resonance. This resonance can nullify the membrane capacitance and solves the RC time constant problem for OHCs. Therefore, avian and mammalian ears solve the same problem in the opposite way. This article is part of the Special Issue Outer hair cell Edited by Joseph Santos-Sacchi and Kumar Navaratnam.
禽类的毛细胞依赖于电共振来实现频率选择性。频率范围的上限受到毛细胞的 RC 时间常数的限制，因为调谐的灵敏度要求共振频率必须低于 RC 滚降频率。相比之下，哺乳动物耳朵的频率选择性的基础是内耳的调谐机械振动。这种机械振动由具有运动性（或压电性）的外毛细胞 (OHC) 支持，由感受器电位驱动。因此，它也受到 RC 时间常数问题的影响。OHC 与具有机械共振的系统的关联导致了压电共振。这种共振可以抵消膜电容，并解决 OHC 的 RC 时间常数问题。因此，禽类和哺乳动物的耳朵以相反的方式解决了相同的问题。本文是由 Joseph Santos-Sacchi 和 Kumar Navaratnam 编辑的特刊“外毛细胞”的一部分。
