Neuronal Avalanches in Input and Associative Layers of Auditory Cortex
Neuronal Avalanches in Input and Associative Layers of Auditory Cortex
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DOI：
10.3389/fnsys.2019.00045
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发表时间：
2019-09-04
影响因子：
3
通讯作者：
Kanold, Patrick O.
中科院分区：
文献类型：
--
作者：
Bowen, Zac;Winkowski, Daniel E.;Kanold, Patrick O.
初级听觉皮质处理声学序列，以感知有行为意义的声音，如语音。声音信息到达其输入层4，从那里活动传播到关联层2/3。目前尚不清楚在声音处理过程中，神经元群体活动是否存在跨层和声音水平的特征组织。在这里，我们识别神经元雪崩，在理论和实验中已经证明，它可以最大限度地扩大动态范围，并优化网络内和网络之间的信息传输，在初级听觉皮质。我们使用活体双光子成像技术对小鼠A1皮层L4和L2/3层的锥体神经元进行成像，以表征自发活动的神经元群体，即在没有声音刺激的情况下，以及在不同声级的单频音调刺激下招募的神经元的数量。单频声音在两层都招募了具有广泛频率选择性的神经元。我们将神经元集合定义为在成像的时间分辨率下，在连续的时间窗口内或期间活跃的神经元。对于这两层，在自发活动和声音呈现期间，神经元团的大小都有很大的变化。集合的大小按照幂定律分布，这是神经元雪崩的标志，并且在不同的声音级别上是相似的。声音激活的雪崩由具有不同调谐偏好的神经元组成，但具有与雪崩大小无关的选择性。我们的结果表明，为雪崩确定的优化原则指导了在刺激处理过程中和中间过程中听觉皮质L4和L2/3的群体活动。
The primary auditory cortex processes acoustic sequences for the perception of behaviorally meaningful sounds such as speech. Sound information arrives at its input layer four from where activity propagates to associative layer 2/3. It is currently not known whether there is a characteristic organization of neuronal population activity across layers and sound levels during sound processing. Here, we identify neuronal avalanches, which in theory and experiments have been shown to maximize dynamic range and optimize information transfer within and across networks, in primary auditory cortex. We used in vivo 2-photon imaging of pyramidal neurons in cortical layers L4 and L2/3 of mouse A1 to characterize the populations of neurons that were active spontaneously, i.e., in the absence of a sound stimulus, and those recruited by single-frequency tonal stimuli at different sound levels. Single-frequency sounds recruited neurons of widely ranging frequency selectivity in both layers. We defined neuronal ensembles as neurons being active within or during successive temporal windows at the temporal resolution of our imaging. For both layers, neuronal ensembles were highly variable in size during spontaneous activity as well as during sound presentation. Ensemble sizes distributed according to power laws, the hallmark of neuronal avalanches, and were similar across sound levels. Avalanches activated by sound were composed of neurons with diverse tuning preference, yet with selectivity independent of avalanche size. Our results suggest that optimization principles identified for avalanches guide population activity in L4 and L2/3 of auditory cortex during and in-between stimulus processing.