Gain Control in the Auditory Cortex Evoked by Changing Temporal Correlation of Sounds.
Gain Control in the Auditory Cortex Evoked by Changing Temporal Correlation of Sounds.
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通过改变声音的时间相关性来获得对听觉皮层的控制。
DOI：
10.1093/cercor/bhw083
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
Geffen,MariaN
中科院分区：
文献类型：
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作者：
Natan,RyanG;Carruthers,IsaacM;Mwilambwe-Tshilobo,Laetitia;Geffen,MariaN
自然声音在其频谱时间结构中表现出统计变化。这种变化对于识别独特的环境声音和语音交流至关重要。使用有限的资源，听觉系统必须在时间统计的整个变化范围内创建声音的忠实表示。对人类的成像研究表明，听觉皮层对时间相关性很敏感。然而，听觉皮层代表声音的频谱时间结构的机制以及神经元活动如何适应截然不同的统计数据仍然知之甚少。在这项研究中，我们记录了清醒大鼠初级听觉皮层神经元对具有系统性变化的时间相关性的声音的反应，以确定此功能是否以及如何改变声音编码。神经元对刺激时间相关性变化的反应。这种适应是介导的神经元反应的放电率增益的变化，而不是他们的spectrotemporal属性。这种增益自适应允许神经元在具有不同统计数据的刺激中保持相似的放电率，从而保持其有效编码时间调制的能力。这种动态增益控制机制可能是理解不同背景下的发声和其他自然声音的基础，通过拉伸或压缩受到时间相关结构的扭曲。
Natural sounds exhibit statistical variation in their spectrotemporal structure. This variation is central to identification of unique environmental sounds and to vocal communication. Using limited resources, the auditory system must create a faithful representation of sounds across the full range of variation in temporal statistics. Imaging studies in humans demonstrated that the auditory cortex is sensitive to temporal correlations. However, the mechanisms by which the auditory cortex represents the spectrotemporal structure of sounds and how neuronal activity adjusts to vastly different statistics remain poorly understood. In this study, we recorded responses of neurons in the primary auditory cortex of awake rats to sounds with systematically varied temporal correlation, to determine whether and how this feature alters sound encoding. Neuronal responses adapted to changing stimulus temporal correlation. This adaptation was mediated by a change in the firing rate gain of neuronal responses rather than their spectrotemporal properties. This gain adaptation allowed neurons to maintain similar firing rates across stimuli with different statistics, preserving their ability to efficiently encode temporal modulation. This dynamic gain control mechanism may underlie comprehension of vocalizations and other natural sounds under different contexts, subject to distortions in temporal correlation structure via stretching or compression.