美国西北大学Andrew Miri团队取得一项新突破。他们的研究开发出了运动皮层对小鼠自然攀爬过程中肢体肌肉活动的选择性直接影响。相关论文于2025年11月6日发表在《自然—神经科学》杂志上。

在这里，研究组在老鼠身上进行了动物行为学启发的攀爬行为。小组量化了前肢初级运动皮层（前肢尾端区）在攀爬过程中表达的脚掌活动状态对脚掌的直接影响。研究人员发现，尾端前肢区域通过选择性地激活某些细胞来指导细胞活动模式，而较少地激活或抑制其拮抗剂。从神经像素记录中，该课题组确定了运动皮层活动的线性组合（组成部分），这些活动与这些效应共同变化。这些成分部分不同于那些与细胞活性共变的成分，几乎完全不同于那些与运动学共变的成分。总的来说，他们的结果揭示了一种有指导意义的直接运动皮层对肢体肌肉的影响，这种影响在运动行为中是选择性的，并且依赖于不同的神经活动子空间。

据介绍，运动皮质输出何时以及如何通过下降投射直接影响肢体肌肉活动仍然不清楚，阻碍了对运动控制的机制理解。

附：英文原文

Title: Selective direct influence of motor cortex on limb muscle activity during naturalistic climbing in mice

Author: Koh, Natalie, Ma, Zhengyu, Sarup, Abhishek, Kristl, Amy C., Agrios, Mark, Young, Margaret, Miri, Andrew

Issue&Volume: 2025-11-06

Abstract: When and how motor cortical output directly influences limb muscle activity through descending projections remain poorly resolved, impeding a mechanistic understanding of motor control. Here we addressed this in mice performing an ethologically inspired climbing behavior. We quantified the direct influence of forelimb primary motor cortex (caudal forelimb area) on muscles across the muscle activity states expressed during climbing. We found that the caudal forelimb area instructs muscle activity pattern by selectively activating certain muscles, while less frequently activating or suppressing their antagonists. From Neuropixels recordings, we identified linear combinations (components) of motor cortical activity that covary with these effects. These components differ partially from those that covary with muscle activity and differ almost completely from those that covary with kinematics. Collectively, our results reveal an instructive direct motor cortical influence on limb muscles that is selective within a motor behavior and reliant on a distinct neural activity subspace.

DOI: 10.1038/s41593-025-02093-z

Source: https://www.nature.com/articles/s41593-025-02093-z