The role of mediodorsal thalamus in temporal differentiation of reward-guided actions
The role of mediodorsal thalamus in temporal differentiation of reward-guided actions
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DOI：
10.3389/fnint.2010.00014
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发表时间：
2010-01-01
影响因子：
3.5
通讯作者：
Yin, Henry H.
中科院分区：
文献类型：
--
作者：
Yu, Chunxiu;Gupta, Jay;Yin, Henry H.
丘脑内侧区(MD)是参与学习和产生目标定向动作的神经网络的重要组成部分。这里报道的一系列实验考察了MD对奖励引导行为的时间差异的贡献。在实验1中，我们训练大鼠进行离散试验，固定标准的时间区分任务，在该任务中，只奖励超过阈值持续时间值的杠杆按压。训练前MD皮损通过增加动作时程分布的离散度，损害了动作时程的时间分化。训练后的MD损伤也损害了分化，但通过减少平均发射的按压持续时间，从而改变了分布而不增加离散度。在实验2中，我们训练大鼠将杠杆按压间隔在标准按压间隔之上，以获得奖励。训练前和训练后的MD损伤都损害了按压间期的分化。这些结果表明，MD在动作分化的获得和表达中起着重要的作用。
The mediodorsal thalamus (MD) is a crucial component of the neural network involved in the learning and generation of goal-directed actions. A series of experiments reported here examined the contributions of MD to the temporal differentiation of reward-guided actions. In Experiment 1, we trained rats on a discrete-trial, fi xed-criterion temporal differentiation task, in which only lever presses exceeding a threshold duration value were rewarded. Pre-training MD lesions impaired temporal differentiation of action duration, by increasing the dispersion of the duration distribution. Post-training MD lesions also impaired differentiation, but by reducing the average emitted press durations, thus shifting the distribution without increasing the dispersion. In Experiment 2, we trained rats to space their lever pressing above criterion interpress- intervals in order to earn rewards. Both pre-training and post-training MD lesions impaired the differentiation of inter-press-intervals. These results show that MD plays an important role in the acquisition and expression of action differentiation.