Chaotic Dynamics Enhance the Sensitivity of Inner Ear Hair Cells
Chaotic Dynamics Enhance the Sensitivity of Inner Ear Hair Cells
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DOI：
10.1038/s41598-019-54952-y
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发表时间：
2019-12-05
影响因子：
4.6
通讯作者：
Bozovic, Dolores
中科院分区：
文献类型：
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作者：
Faber, Justin;Bozovic, Dolores
听觉和前庭系统的毛细胞能够检测到声音，这些声音引起发束的亚纳米振动，低于周围流体的随机噪声水平。此外，听觉系统在亚毫秒范围内表现出非常快的响应时间。我们建议，混沌动力学提高的灵敏度和时间分辨率的毛束响应，我们提供了实验和理论证据，这种效果。我们使用Kolmogorov熵来衡量系统中的混沌程度和转移熵来量化检测器捕获的刺激信息量。通过改变周围流体的粘度和离子组成，我们能够在实验上调节体外毛束动力学中观察到的混沌程度。我们一致发现，毛束是最敏感的小振幅的刺激时，它是在弱混沌政权的平衡。此外，我们表明，一个力阶跃的响应时间随混沌水平的增加而减少。这些结果与我们对混沌霍普夫振子的数值模拟结果一致，表明混沌可能是毛细胞高灵敏度和快速时间响应的原因。
Hair cells of the auditory and vestibular systems are capable of detecting sounds that induce sub-nanometer vibrations of the hair bundle, below the stochastic noise levels of the surrounding fluid. Furthermore, the auditory system exhibits a highly rapid response time, in the sub-millisecond regime. We propose that chaotic dynamics enhance the sensitivity and temporal resolution of the hair bundle response, and we provide experimental and theoretical evidence for this effect. We use the Kolmogorov entropy to measure the degree of chaos in the system and the transfer entropy to quantify the amount of stimulus information captured by the detector. By varying the viscosity and ionic composition of the surrounding fluid, we are able to experimentally modulate the degree of chaos observed in the hair bundle dynamics in vitro. We consistently find that the hair bundle is most sensitive to a stimulus of small amplitude when it is poised in the weakly chaotic regime. Further, we show that the response time to a force step decreases with increasing levels of chaos. These results agree well with our numerical simulations of a chaotic Hopf oscillator and suggest that chaos may be responsible for the high sensitivity and rapid temporal response of hair cells.