Differential Encoding of Time by Prefrontal and Striatal Network Dynamics
Differential Encoding of Time by Prefrontal and Striatal Network Dynamics
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DOI：
10.1523/jneurosci.1789-16.2016
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发表时间：
2017-01-25
影响因子：
5.3
通讯作者：
Masmanidis, Sotiris C.
中科院分区：
文献类型：
--
作者：
Bakhurin, Konstantin I.;Goudar, Vishwa;Masmanidis, Sotiris C.
告诉时间是许多形式的学习和行为的基础，包括对奖励事件的预期。虽然时间背后的神经机制仍然未知，但计算模型已经提出，大脑在神经网络的动力学中代表时间。与这一假设相一致的是，在大脑的一些区域（包括纹状体和皮层）中，神经活动的动态变化模式已经被证明可以对逝去的时间进行编码。然而，到目前为止，还没有研究明确量化和对比不同区域如何通过同时记录来自多个区域的大量单位来编码时间。在这里，我们进行了大规模的细胞外记录在纹状体和眶额皮质的小鼠，学习刺激和奖励之间的时间关系，并报告他们的反应与预期舔。我们使用了一种机器学习算法来量化神经元群体对刺激开始后经过的时间的编码程度。纹状体和皮质网络编码的时间，但纹状体网络优于眶额皮质，同时和非同时记录的corticostriatal数据集复制的发现。纹状体网络也更可靠地预测动物何时会在实际舔之前舔到大约1秒。我们的研究结果与以下假设一致，即时间信息以广泛分布的方式编码在多个大脑区域中，但纹状体可能在计时方面具有特殊作用，因为它具有更准确的“时钟”，因为它整合了多个皮层区域的信息。
Telling time is fundamental to many forms of learning and behavior, including the anticipation of rewarding events. Although the neural mechanisms underlying timing remain unknown, computational models have proposed that the brain represents time in the dynamics of neural networks. Consistent with this hypothesis, changing patterns of neural activity dynamically in a number of brain areas-including the striatum and cortex-has been shown to encode elapsed time. To date, however, no studies have explicitly quantified and contrasted how well different areas encode time by recording large numbers of units simultaneously from more than one area. Here, we performed large-scale extracellular recordings in the striatum and orbitofrontal cortex of mice that learned the temporal relationship between a stimulus and a reward and reported their response with anticipatory licking. We used a machine-learning algorithm to quantify how well populations of neurons encoded elapsed time from stimulus onset. Both the striatal and cortical networks encoded time, but the striatal network outperformed the orbitofrontal cortex, a finding replicated both in simultaneously and nonsimultaneously recorded corticostriatal datasets. The striatal network was also more reliable in predicting when the animals would lick up to similar to 1 s before the actual lick occurred. Our results are consistent with the hypothesis that temporal information is encoded in a widely distributed manner throughout multiple brain areas, but that the striatummayhave a privileged role in timing because it has a more accurate "clock" as it integrates information across multiple cortical areas.