Fujiyama Fumino, Takahashi Susumu, Karube Fuyuki
Laboratory of Neural Circuitry, Department of Systems Neuroscience, Graduate School of Brain Science, Doshisha University Kyoto, Japan ; Core Research for Evolutional Science and Technology, Japan Science and Technology Agency Tokyo, Japan.
Laboratory of Neural Circuitry, Department of Systems Neuroscience, Graduate School of Brain Science, Doshisha University Kyoto, Japan.
Front Neurosci. 2015 Feb 5;9:6. doi: 10.3389/fnins.2015.00006. eCollection 2015.
Electrophysiological studies in monkeys have shown that dopaminergic neurons respond to the reward prediction error. In addition, striatal neurons alter their responsiveness to cortical or thalamic inputs in response to the dopamine signal, via the mechanism of dopamine-regulated synaptic plasticity. These findings have led to the hypothesis that the striatum exhibits synaptic plasticity under the influence of the reward prediction error and conduct reinforcement learning throughout the basal ganglia circuits. The reinforcement learning model is useful; however, the mechanism by which such a process emerges in the basal ganglia needs to be anatomically explained. The actor-critic model has been previously proposed and extended by the existence of role sharing within the striatum, focusing on the striosome/matrix compartments. However, this hypothesis has been difficult to confirm morphologically, partly because of the complex structure of the striosome/matrix compartments. Here, we review recent morphological studies that elucidate the input/output organization of the striatal compartments.
对猴子的电生理研究表明，多巴胺能神经元对奖励预测误差做出反应。此外，纹状体神经元通过多巴胺调节的突触可塑性机制，响应多巴胺信号，改变其对皮质或丘脑输入的反应性。这些发现引发了这样一种假说，即纹状体在奖励预测误差的影响下表现出突触可塑性，并在整个基底神经节回路中进行强化学习。强化学习模型是有用的；然而，这样一个过程在基底神经节中出现的机制需要从解剖学上进行解释。此前有人提出了行动者-评判者模型，并通过纹状体内存在角色共享对其进行了扩展，重点关注纹状体小体/基质区室。然而，这一假说在形态学上难以证实，部分原因是纹状体小体/基质区室的结构复杂。在这里，我们回顾了最近的形态学研究，这些研究阐明了纹状体区室的输入/输出组织。
