Hand dexterity has uniquely developed in higher primates and is thought to rely on the direct corticomotoneuronal (CM) pathway. Recent studies have shown that rodents and carnivores lack the direct CM pathway but can control certain levels of dexterous hand movements through various indirect CM pathways. Some homologous pathways also exist in higher primates, and among them, propriospinal (PrS) neurons in the mid-cervical segments (C3-C4) are significantly involved in hand dexterity. When the direct CM pathway was lesioned caudal to the PrS and transmission of cortical commands to hand motoneurons via the PrS neurons remained intact, dexterous hand movements could be significantly recovered. This recovery model was intensively studied, and it was found that, in addition to the compensation by the PrS neurons, a large-scale reorganization in the bilateral cortical motor-related areas and mesolimbic structures contributed to recovery. Future therapeutic strategies should target these multihierarchical areas.

中文翻译：

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中枢神经系统损伤后的敏捷手部运动及其恢复。

手灵巧性在高等灵长类动物中已得到独特发展，并且被认为依赖于直接的皮质网膜泌尿激素（CM）途径。最近的研究表明，啮齿动物和食肉动物没有直接的CM通路，但是可以通过各种间接的CM通路控制一定程度的灵巧手运动。在高级灵长类动物中也存在一些同源途径，其中，子宫颈中段（C3-C4）中的脊椎（PrS）神经元与手的敏捷性显着相关。当直接CM路径在PrS尾部病变，并且皮层命令通过PrS神经元传递至手运动神经元时，其手部运动可以得到明显恢复。对该恢复模型进行了深入研究，发现除了PrS神经元的补偿外，双边皮层运动相关区域和中脑边缘结构的大规模重组有助于恢复。未来的治疗策略应针对这些多层次领域。