Beyond reward prediction errors: the role of dopamine in movement kinematics
Beyond reward prediction errors: the role of dopamine in movement kinematics
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DOI：
10.3389/fnint.2015.00039
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发表时间：
2015-05-27
影响因子：
3.5
通讯作者：
Yin, Henry H.
中科院分区：
文献类型：
--
作者：
Barter, Joseph W.;Li, Suellen;Yin, Henry H.
我们记录了多巴胺（DA）神经元的活动在黑质pars延髓在不受约束的小鼠，同时监测他们的运动与视频跟踪。我们的方法允许一个不带偏见的检查之间的连续关系的单一单位的活动和行为。虽然DA神经元表现出特征性的突发放电后的线索或奖励介绍，如前所述，他们的活动可以解释的代表性的实际运动学。与相邻的网状部GABA能输出神经元不同，DA神经元代表速度或加速度的矢量分量。我们发现神经元与上下左右四个方向的运动有关。对于水平运动，神经元有明显的偏侧化：左侧黑质含有更多的神经元，而右侧黑质含有更多的神经元。在使用蔗糖的食欲试验和使用喷气的厌恶试验中发现了DA活性和运动运动学之间的关系，表明这些神经元属于速度控制回路，可以用于任何目的，无论是寻求奖励还是避免伤害。为了支持这一结论，用选择性光遗传学刺激模拟DA神经元的阶段性激活也可以产生运动。相反，流行的假设，DA神经元编码奖励预测错误，我们的研究结果表明，黑质纹状体DA在控制自愿运动的运动学起着至关重要的作用。我们假设，DA信号实现自适应过渡控制的增益调整，并描述了一个新的模型的基底神经节（BG），其中DA的功能，以调整过渡控制器的增益。该模型对我们理解涉及DA和BG的运动障碍具有重要意义。
We recorded activity of dopamine (DA) neurons in the substantia nigra pars compacta in unrestrained mice while monitoring their movements with video tracking. Our approach allows an unbiased examination of the continuous relationship between single unit activity and behavior. Although DA neurons show characteristic burst firing following cue or reward presentation, as previously reported, their activity can be explained by the representation of actual movement kinematics. Unlike neighboring pars reticulata GABAergic output neurons, which can represent vector components of position, DA neurons represent vector components of velocity or acceleration. We found neurons related to movements in four directions up, down, left, right. For horizontal movements, there is significant lateralization of neurons: the left nigra contains more rightward neurons, whereas the right nigra contains more leftward neurons. The relationship between DA activity and movement kinematics was found on both appetitive trials using sucrose and aversive trials using air puff, showing that these neurons belong to a velocity control circuit that can be used for any number of purposes, whether to seek reward or to avoid harm. In support of this conclusion, mimicry of the phasic activation of DA neurons with selective optogenetic stimulation could also generate movements. Contrary to the popular hypothesis that DA neurons encode reward prediction errors, our results suggest that nigrostriatal DA plays an essential role in controlling the kinematics of voluntary movements. We hypothesize that DA signaling implements gain adjustment for adaptive transition control, and describe a new model of the basal ganglia (BG) in which DA functions to adjust the gain of the transition controller. This model has significant implications for our understanding of movement disorders implicating DA and the BG.