Modulation of neuronal activity by reward identity in the monkey subthalamic nucleus
Modulation of neuronal activity by reward identity in the monkey subthalamic nucleus
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DOI：
10.1111/ejn.12938
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发表时间：
2015-07-01
影响因子：
3.4
通讯作者：
Apicella, Paul
中科院分区：
文献类型：
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作者：
Espinosa-Parrilla, Juan-Francisco;Baunez, Christelle;Apicella, Paul
丘脑底核（subthalamic nucleus，简称丘脑底核）被认为是奖赏敏感基底神经节回路的重要组成部分。这一观点尤其得到了大脑失活后观察到的行为变化的支持，这可能反映了行为动机控制的障碍。然而，目前还不清楚大脑皮层如何整合奖励信息，以及这种整合在多大程度上与行为相关。在这项研究中，猴子的神经元的反应特性进行了研究，达到运动的线索预测即将到来的液体奖励（果汁或水）的身份。虽然运动的时间可靠地表明，猴子有更大的动机果汁比水，很少有任务相关的神经元活动的变化取决于预期的奖励的性质。相反地，当猴子被要求选择一种导致果汁或水输送的反应时，动物表现出对果汁的明显偏好，并且超过一半的神经元根据所获得的奖励进行了差异调节，主要是在猴子公开选择行动之后。在这种情况下，当猴子没有选择果汁奖励时，整个神经元群体的活动增加专门跟随动作结果。这些结果表明，当需要在响应选项之间进行选择时，神经元编码是否收到了首选奖励。这种不同的神经元活动可能反映了大脑皮层参与评估所选行为的奖励价值，从而突出了它对决策过程的贡献。
The subthalamic nucleus (STN) has been argued to be an important component of reward-sensitive basal ganglia circuitry. This view is especially supported by the behavioral changes observed after STN inactivation, which could reflect impairments in the motivational control of action. However, it is still unclear how the STN integrates reward information and to what extent such integration correlates with behavior. In this study, the response properties of STN neurons in monkeys performing reaching movements with a cue predicting the identity of an upcoming liquid reward (juice or water) were investigated. Although the timing of movements reliably indicated that monkeys had greater motivation for juice than water, rarely did task-related changes in neuronal activity depend on the nature of the expected reward. Conversely, when presented with a choice of selecting a response that leads to juice or water delivery, animals showed a clear preference for juice and more than half of the neurons were differentially modulated dependent on the reward obtained, mostly after the monkeys's overt choice of action. Under such circumstances, an increase in activity specifically followed the action outcomes across the population of neurons when monkeys failed to choose the juice reward. These results indicate that STN neurons encode whether or not a preferred reward had been received when a choice between response alternatives is required. This differential neuronal activity might reflect the participation of the STN in evaluating the reward value of chosen actions, thus highlighting its contribution to decision-making processes.