Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, USA.
Nat Neurosci. 2021 Dec;24(12):1721-1732. doi: 10.1038/s41593-021-00939-w. Epub 2021 Nov 4.
Many models of motor control emphasize the role of sensorimotor cortex in movement, principally through the projections that corticospinal neurons (CSNs) make to the spinal cord. Additionally, CSNs possess expansive supraspinal axon collaterals, the functional organization of which is largely unknown. Using anatomical and electrophysiological circuit-mapping techniques in the mouse, we reveal dorsolateral striatum as the preeminent target of CSN collateral innervation. We found that this innervation is biased so that CSNs targeting different striatal pathways show biased targeting of spinal cord circuits. Contrary to more conventional perspectives, CSNs encode not only individual movements, but also information related to the onset and offset of motor sequences. Furthermore, similar activity patterns are broadcast by CSN populations targeting different striatal circuits. Our results reveal a logic of coordinated connectivity between forebrain and spinal circuits, where separate CSN modules broadcast similarly complex information to downstream circuits, suggesting that differences in postsynaptic connectivity dictate motor specificity.
许多运动控制模型强调感觉运动皮层在运动中的作用，主要是通过皮质脊髓神经元 (CSN) 向脊髓的投射。此外，CSN 还拥有广泛的脊髓上轴突侧支，其功能组织在很大程度上尚不清楚。我们使用小鼠中的解剖学和电生理学电路映射技术，揭示了背外侧纹状体是 CSN 侧支支配的主要靶标。我们发现这种支配是有偏向的，以至于靶向不同纹状体途径的 CSN 表现出对脊髓回路的偏向性靶向。与更传统的观点相反，CSN 不仅编码单个运动，还编码与运动序列开始和结束相关的信息。此外，靶向不同纹状体回路的 CSN 群体广播类似的活动模式。我们的结果揭示了大脑前脑和脊髓回路之间协调连接的逻辑，其中单独的 CSN 模块向下游回路广播类似复杂的信息，这表明突触后连接的差异决定了运动的特异性。
