Proportional spike-timing precision and firing reliability underlie efficient temporal processing of periodicity and envelope shape cues.
Proportional spike-timing precision and firing reliability underlie efficient temporal processing of periodicity and envelope shape cues.
复制标题
比例尖峰定时精度和发射可靠性是周期性和包络形状线索的有效时间处理的基础。
DOI：
10.1152/jn.01080.2010
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发表时间：
2013
影响因子：
2.5
通讯作者：
Escabí,MA
中科院分区：
文献类型：
--
作者：
Zheng,Y;Escabí,MA
时间的声音线索是必不可少的声音识别，音高，节奏和音色的感知，但听觉神经元如何编码这些线索是正在进行的辩论的主题。速率编码理论提出，时间的声音特征表示的速率调谐调制滤波器。然而，压倒性的证据也表明，精确的尖峰时间是神经代码的一个基本属性。在这里，我们证明了听觉中脑中的单个神经元采用比例编码，其中尖峰定时精度和发射可靠性与声音包络线索协变，以提供刺激的有效表示。尖峰定时精度随时间尺度和声音包络的形状而系统地变化，但在很大程度上独立于声音调制频率，这是音高的一个重要线索。与此相反，尖峰计数的可靠性受到强烈的影响调制频率。尖峰定时精度从短暂瞬变声音的亚毫秒扩展到具有缓慢变化包络的声音的数十毫秒。信息论分析进一步证实，尖峰定时精度强烈地依赖于声音包络形状，而发射可靠性强烈地受声音调制频率的影响。信息效率和总信息量都受到发射可靠性和尖峰定时精度的限制，反映了声音结构。这一结果支持了听觉中脑的时间编码策略，其中尖峰定时精度和发射可靠性的比例变化可以有效地信号形状和周期性时间线索。
Temporal sound cues are essential for sound recognition, pitch, rhythm, and timbre perception, yet how auditory neurons encode such cues is subject of ongoing debate. Rate coding theories propose that temporal sound features are represented by rate tuned modulation filters. However, overwhelming evidence also suggests that precise spike timing is an essential attribute of the neural code. Here we demonstrate that single neurons in the auditory midbrain employ a proportional code in which spike-timing precision and firing reliability covary with the sound envelope cues to provide an efficient representation of the stimulus. Spike-timing precision varied systematically with the timescale and shape of the sound envelope and yet was largely independent of the sound modulation frequency, a prominent cue for pitch. In contrast, spike-count reliability was strongly affected by the modulation frequency. Spike-timing precision extends from sub-millisecond for brief transient sounds up to tens of milliseconds for sounds with slow-varying envelope. Information theoretic analysis further confirms that spike-timing precision depends strongly on the sound envelope shape, while firing reliability was strongly affected by the sound modulation frequency. Both the information efficiency and total information were limited by the firing reliability and spike-timing precision in a manner that reflected the sound structure. This result supports a temporal coding strategy in the auditory midbrain where proportional changes in spike-timing precision and firing reliability can efficiently signal shape and periodicity temporal cues.