Subpopulations of neurons in lOFC encode previous and current rewards at time of choice.
Subpopulations of neurons in lOFC encode previous and current rewards at time of choice.
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DOI：
10.7554/elife.70129
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发表时间：
2021-10-25
期刊：
影响因子：
7.7
通讯作者：
Constantinople CM
中科院分区：
文献类型：
--
作者：
Hocker DL;Brody CD;Savin C;Constantinople CM
对外侧眶额皮质（lOFC）神经动力学的研究表明，编码不同行为方面（如价值）的神经元子集可能会投射到共同的下游目标。然而，目前尚不清楚的是，奖励历史是否支持lOFC在学习中的作用，这可能是lOFC的功能亚群所代表的。在此之前，我们分析了执行基于价值的决策任务的大鼠的神经记录，并记录了需要lOFC的一次又一次学习（Constantinople et al., 2019）。在这里，我们描述了lOFC神经元在行为过程中的功能亚群，包括它们对任务变量的编码。我们发现了五种不同的lOFC神经元簇，要么是基于它们的试验平均刺激时间直方图（pths）的聚类，要么是基于它们与不同任务变量相一致的平均条件放电率定义的特征空间。我们观察到奖励属性编码较弱，但奖励历史编码较强，动物的左或右选择，以及所有集群的奖励接收。然而，只有一个集群编码了动物在选择前不久的奖励历史，这表明在选择时整合先前和当前试验结果的可能作用。在最近的一项研究中（Hirokawa et al., 2019），该簇对已识别的皮质纹状体投射神经元也表现出定性相似的反应，并表明lOFC神经元亚群在调解一次次学习中的可能作用。
Studies of neural dynamics in lateral orbitofrontal cortex (lOFC) have shown that subsets of neurons that encode distinct aspects of behavior, such as value, may project to common downstream targets. However, it is unclear whether reward history, which may subserve lOFC’s well-documented role in learning, is represented by functional subpopulations in lOFC. Previously, we analyzed neural recordings from rats performing a value-based decision-making task, and we documented trial-by-trial learning that required lOFC (Constantinople et al., 2019). Here, we characterize functional subpopulations of lOFC neurons during behavior, including their encoding of task variables. We found five distinct clusters of lOFC neurons, either based on clustering of their trial-averaged peristimulus time histograms (PSTHs), or a feature space defined by their average conditional firing rates aligned to different task variables. We observed weak encoding of reward attributes, but stronger encoding of reward history, the animal’s left or right choice, and reward receipt across all clusters. Only one cluster, however, encoded the animal’s reward history at the time shortly preceding the choice, suggesting a possible role in integrating previous and current trial outcomes at the time of choice. This cluster also exhibits qualitatively similar responses to identified corticostriatal projection neurons in a recent study (Hirokawa et al., 2019), and suggests a possible role for subpopulations of lOFC neurons in mediating trial-by-trial learning.