毛细胞运动作为耳蜗放大器的有效性。
Effectiveness of hair bundle motility as the cochlear amplifier.
机构信息
Biophysics Section, Laboratory of Cellular Biology, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Rockville, Maryland, USA.
出版信息
Biophys J. 2009 Nov 18;97(10):2653-63. doi: 10.1016/j.bpj.2009.08.039.
The effectiveness of hair bundle motility in mammalian and avian ears is studied by examining energy balance for a small sinusoidal displacement of the hair bundle. The condition that the energy generated by a hair bundle must be greater than energy loss due to the shear in the subtectorial gap per hair bundle leads to a limiting frequency that can be supported by hair-bundle motility. Limiting frequencies are obtained for two motile mechanisms for fast adaptation, the channel re-closure model and a model that assumes that fast adaptation is an interplay between gating of the channel and the myosin motor. The limiting frequency obtained for each of these models is an increasing function of a factor that is determined by the morphology of hair bundles and the cochlea. Primarily due to the higher density of hair cells in the avian inner ear, this factor is approximately 10-fold greater for the avian ear than the mammalian ear, which has much higher auditory frequency limit. This result is consistent with a much greater significance of hair bundle motility in the avian ear than that in the mammalian ear.
通过研究毛细胞束的小正弦位移的能量平衡，研究了哺乳动物和鸟类耳朵中毛细胞束运动的效果。毛细胞束产生的能量必须大于每个毛细胞束的下盖间隙剪切引起的能量损失的条件，导致毛细胞束运动可以支持的极限频率。对于快速适应的两种运动机制，即通道再关闭模型和假设快速适应是通道门控和肌球蛋白运动相互作用的模型，获得了极限频率。对于这些模型中的每一个，极限频率都是由毛细胞束和耳蜗的形态决定的一个因子的增函数。主要由于禽类内耳中的毛细胞密度较高，该因子对于禽类耳朵大约是哺乳动物耳朵的 10 倍，而哺乳动物耳朵的听觉频率上限要高得多。这个结果与毛细胞束运动在禽类耳朵中的重要性远远大于在哺乳动物耳朵中的重要性一致。
Zotero 插件