美国霍华德休斯医学研究所Stephen J. Huston团队近期取得重要工作进展，他们研究提出，运动神经元通过本体感觉塑造产生特定姿势的运动。相关研究成果2024年3月20日在线发表于《自然》杂志上。

据介绍，运动神经元是大脑控制身体运动的最后一条共同途径，是构成所有运动的基本要素。然而，单个运动神经元如何在自然运动过程中对控制做出贡献仍不清楚。

研究人员从解剖学和功能上描述了控制果蝇头部运动的运动神经元的个体作用。与直觉相反，研究人员发现单个运动神经元的活动会使头部朝着不同的方向旋转，这取决于头部的起始姿势，因此头部会朝着由受刺激运动神经元的身份决定的姿势收敛。反馈模型预测，这种收敛行为是运动神经元驱动与本体感觉反馈相互作用的结果。研究人员识别并从基因上抑制了一类本体感觉神经元，该神经元改变了反馈模型预测的运动神经元诱导的收敛。

总之，这些数据为大脑如何控制运动提供了一个框架：大脑不是通过激活一组固定的运动神经元直接产生特定方向的运动，而是通过向持续的本体感觉-运动回路添加偏差来控制运动。

附： 英文原文

Title: Motor neurons generate pose-targeted movements via proprioceptive sculpting

Author: Gorko, Benjamin, Siwanowicz, Igor, Close, Kari, Christoforou, Christina, Hibbard, Karen L., Kabra, Mayank, Lee, Allen, Park, Jin-Yong, Li, Si Ying, Chen, Alex B., Namiki, Shigehiro, Chen, Chenghao, Tuthill, John C., Bock, Davi D., Rouault, Herv, Branson, Kristin, Ihrke, Gudrun, Huston, Stephen J.

Issue&Volume: 2024-03-20

Abstract: Motor neurons are the final common pathway1 through which the brain controls movement of the body, forming the basic elements from which all movement is composed. Yet how a single motor neuron contributes to control during natural movement remains unclear. Here we anatomically and functionally characterize the individual roles of the motor neurons that control head movement in the fly, Drosophila melanogaster. Counterintuitively, we find that activity in a single motor neuron rotates the head in different directions, depending on the starting posture of the head, such that the head converges towards a pose determined by the identity of the stimulated motor neuron. A feedback model predicts that this convergent behaviour results from motor neuron drive interacting with proprioceptive feedback. We identify and genetically2 suppress a single class of proprioceptive neuron3 that changes the motor neuron-induced convergence as predicted by the feedback model. These data suggest a framework for how the brain controls movements: instead of directly generating movement in a given direction by activating a fixed set of motor neurons, the brain controls movements by adding bias to a continuing proprioceptive–motor loop.

DOI: 10.1038/s41586-024-07222-5

Source: https://www.nature.com/articles/s41586-024-07222-5