Firing Rate Adaptation of the Human Auditory Nerve Optimizes Neural Signal-to-Noise Ratios.
Firing Rate Adaptation of the Human Auditory Nerve Optimizes Neural Signal-to-Noise Ratios.
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人类听觉神经的发射速率适应优化神经信噪比。
DOI：
10.1007/s10162-022-00841-7
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发表时间：
2022
期刊：
影响因子：
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通讯作者：
Dominguez,Juan
中科院分区：
文献类型：
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作者：
Jennings,SkylerG;Dominguez,Juan
在声刺激期间，几种生理机制作用于听觉神经（AN）的响应，导致听觉增益的调整。这些机制包括但不限于：放电率适应、动态范围适应、中耳肌反射和内侧橄榄耳蜗反射。这些机制的潜在作用是在真实的时间中提高AN输出处的神经信噪比（SNR）。这项研究测试了假设，即从人类AN的非侵入性评估推断的神经SNR在声刺激的持续时间内得到改善。在一系列的六个高级别的点击嵌入在一系列的六个较低级别的宽带噪声脉冲串的反应，测量cohesar电位。这种模式引发了一个复合动作电位（CAP），以响应每一个点击和每一个噪音爆发的开始。由每个点击和噪声突发对引起的CAP幅度的比率（即，神经SNR）在六个咔哒声/噪声突发上被跟踪。主要发现是从第一次到第二次咔哒声/噪声突发的神经SNR快速（< 24 ms）增加，与听觉外周响应的实时调整一致，以改善传输到脑干的信号的SNR。分析耳蜗微音和耳道声压记录，以及神经SNR改善的时间过程，支持以下结论：放电率适应可能是改善神经SNR的主要机制，而动态范围适应、中耳肌肉反射和内侧橄榄耳蜗反射对本研究中观察到的效果起次要作用。神经SNR的实时改进是显著的，因为它们对于在存在背景噪声的情况下对语音和其他相关刺激进行鲁棒编码可能是必不可少的。
Several physiological mechanisms act on the response of the auditory nerve (AN) during acoustic stimulation, resulting in an adjustment in auditory gain. These mechanisms include—but are not limited to—firing rate adaptation, dynamic range adaptation, the middle ear muscle reflex, and the medial olivocochlear reflex. A potential role of these mechanisms is to improve the neural signal-to-noise ratio (SNR) at the output of the AN in real time. This study tested the hypothesis that neural SNRs, inferred from non-invasive assessment of the human AN, improve over the duration of acoustic stimulation. Cochlear potentials were measured in response to a series of six high-level clicks embedded in a series of six lower-level broadband noise bursts. This paradigm elicited a compound action potential (CAP) in response to each click and to the onset of each noise burst. The ratio of CAP amplitudes elicited by each click and noise burst pair (i.e., neural SNR) was tracked over the six click/noise bursts. The main finding was a rapid (< 24 ms) increase in neural SNR from the first to the second click/noise burst, consistent with a real-time adjustment in the response of the auditory periphery toward improving the SNR of the signal transmitted to the brainstem. Analysis of cochlear microphonic and ear canal sound pressure recordings, as well as the time course for this improvement in neural SNR, supports the conclusion that firing rate adaptation is likely the primary mechanism responsible for improving neural SNR, while dynamic range adaptation, the middle ear muscle reflex, and the medial olivocochlear reflex played a secondary role on the effects observed in this study. Real-time improvements in neural SNR are significant because they may be essential for robust encoding of speech and other relevant stimuli in the presence of background noise.