Molecular Neurobiology Laboratory, Salk Institute for Biological Studies, La Jolla, United States.
Neurobiology Research Unit, Okinawa Institute of Science and Technology, Okinawa, Japan.
Elife. 2019 Sep 6;8:e49995. doi: 10.7554/eLife.49995.
Cortico-basal ganglia-thalamocortical loops are largely conceived as parallel circuits that process limbic, associative, and sensorimotor information separately. Whether and how these functionally distinct loops interact remains unclear. Combining genetic and viral approaches, we systemically mapped the limbic and motor cortico-basal ganglia-thalamocortical loops in rodents. Despite largely closed loops within each functional domain, we discovered a unidirectional influence of the limbic over the motor loop via ventral striatum-substantia nigra (SNr)-motor thalamus circuitry. Slice electrophysiology verifies that the projection from ventral striatum functionally inhibits nigro-thalamic SNr neurons. In vivo optogenetic stimulation of ventral or dorsolateral striatum to SNr pathway modulates activity in medial prefrontal cortex (mPFC) and motor cortex (M1), respectively. However, whereas the dorsolateral striatum-SNr pathway exerts little impact on mPFC, activation of the ventral striatum-SNr pathway effectively alters M1 activity. These results demonstrate an open cortico-basal ganglia loop whereby limbic information could modulate motor output through ventral striatum control of M1.
皮质-基底神经节-丘脑皮质回路主要被设想为并行回路，分别处理边缘、联想和感觉运动信息。这些功能上不同的回路是否以及如何相互作用尚不清楚。我们结合遗传和病毒方法，系统地绘制了啮齿动物的边缘和运动皮质-基底神经节-丘脑皮质回路。尽管在每个功能域内都有很大程度的闭环，但我们发现边缘回路通过腹侧纹状体-黑质致密部（SNr）-运动丘脑回路对运动回路具有单向影响。切片电生理学证实，腹侧纹状体的投射在功能上抑制了黑质-丘脑 SNr 神经元。在体光遗传学刺激腹侧或背外侧纹状体到 SNr 通路分别调节内侧前额叶皮质（mPFC）和运动皮质（M1）的活动。然而，背外侧纹状体-SNr 通路对 mPFC 的影响很小，而腹侧纹状体-SNr 通路的激活则有效地改变了 M1 的活动。这些结果表明存在一个开放的皮质-基底神经节回路，其中边缘信息可以通过腹侧纹状体对 M1 的控制来调节运动输出。
