Neural Synchrony Gives Rise to Amplitude- and Duration-Invariant Encoding Consistent With Perception of Natural Communication Stimuli
Neural Synchrony Gives Rise to Amplitude- and Duration-Invariant Encoding Consistent With Perception of Natural Communication Stimuli
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DOI：
10.3389/fnins.2020.00079
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发表时间：
2020-02
影响因子：
4.3
通讯作者：
Michael G. Metzen;Volker Hofmann;M. Chacron
中科院分区：
文献类型：
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作者：
Michael G. Metzen;Volker Hofmann;M. Chacron
当面对一个高度可变的环境时，人们仍然对神经群体如何编码和分类自然刺激以产生适当和一致的行为反应知之甚少。在这里，我们研究了具有不同属性的自然通信信号的群体编码（即，振幅和持续时间）的弱电鱼类Apteronotusleptorhynchus的电感觉系统。我们的研究结果表明，虽然单个外周神经元编码不同刺激波形的详细时间过程，但由于活动的协调增加和减少，群体同步性的措施实际上没有变化。一个现象学的数学模型再现了这种不变性，并表明，这可以解释为考虑同质群体的反应是完全由单个神经元放电特性。此外，来自下游中枢神经元的记录显示，同步传入活动实际上被解码，因此很可能被传输到更高的大脑区域。最后，我们证明了在生物体水平上的相关行为反应是不变的。我们的研究结果提供了一种机制，通过这种机制，行为相关的感觉输入的幅度和持续时间不变的编码出现在连续的大脑区域，从而可能会引起不变的行为反应。这样的机制很可能在与电感觉系统共享解剖学和功能特征的其他系统中找到（例如，听觉的、视觉的、前庭的）。
When confronted with a highly variable environment, it remains poorly understood how neural populations encode and classify natural stimuli to give rise to appropriate and consistent behavioral responses. Here we investigated population coding of natural communication signals with different attributes (i.e., amplitude and duration) in the electrosensory system of the weakly electric fish Apteronotus leptorhynchus. Our results show that, while single peripheral neurons encode the detailed timecourse of different stimulus waveforms, measures of population synchrony are effectively unchanged because of coordinated increases and decreases in activity. A phenomenological mathematical model reproduced this invariance and shows that this can be explained by considering homogeneous populations whose responses are solely determined by single neuron firing properties. Moreover, recordings from downstream central neurons reveal that synchronous afferent activity is actually decoded and thus most likely transmitted to higher brain areas. Finally, we demonstrate that the associated behavioral responses at the organism level are invariant. Our results provide a mechanism by which amplitude- and duration-invariant coding of behaviorally relevant sensory input emerges across successive brain areas thereby presumably giving rise to invariant behavioral responses. Such mechanisms are likely to be found in other systems that share anatomical and functional features with the electrosensory system (e.g., auditory, visual, vestibular).