近日，美国华盛顿大学John C. Tuthill等研究人员合作揭示果蝇腿部和翅膀前运动控制网络的突触结构。相关论文于2024年6月26日在线发表在《自然》杂志上。

研究人员利用连接组学分析了控制果蝇腿部和翅膀的前运动回路的布线逻辑。研究人员发现，这两种前运动网络都聚集成模块，将支配具有相关功能的肌肉的运动神经元连接起来。在大多数腿部运动模块中，每个前运动神经元的突触权重与其靶标运动神经元（MN）的大小成正比，从而建立了分级招募MN的回路基础。

相比之下，翅膀前运动网络缺乏按比例的突触连接，这可能使翅膀转向肌肉的招募更加灵活。通过比较同一动物内不同运动控制系统的结构，研究人员发现了前运动网络组织和特化的共同原则，这些原则反映了腿部和翼部运动控制的独特生物力学限制和演化起源。

研究人员表示，动物的运动由MN控制，这些神经元从中枢神经系统发出以激活肌肉。运动神经元的活动由复杂的运动前网络协调，运动前网络可促进单个肌肉对许多不同行为的贡献。

附：英文原文

Title: Synaptic architecture of leg and wing premotor control networks in Drosophila

Author: Lesser, Ellen, Azevedo, Anthony W., Phelps, Jasper S., Elabbady, Leila, Cook, Andrew, Syed, Durafshan Sakeena, Mark, Brandon, Kuroda, Sumiya, Sustar, Anne, Moussa, Anthony, Dallmann, Chris J., Agrawal, Sweta, Lee, Su-Yee J., Pratt, Brandon, Skutt-Kakaria, Kyobi, Gerhard, Stephan, Lu, Ran, Kemnitz, Nico, Lee, Kisuk, Halageri, Akhilesh, Castro, Manuel, Ih, Dodam, Gager, Jay, Tammam, Marwan, Dorkenwald, Sven, Collman, Forrest, Schneider-Mizell, Casey, Brittain, Derrick, Jordan, Chris S., Macrina, Thomas, Dickinson, Michael, Lee, Wei-Chung Allen, Tuthill, John C.

Issue&Volume: 2024-06-26

Abstract: Animal movement is controlled by motor neurons (MNs), which project out of the central nervous system to activate muscles1. MN activity is coordinated by complex premotor networks that facilitate the contribution of individual muscles to many different behaviours2,3,4,5,6. Here we use connectomics7 to analyse the wiring logic of premotor circuits controlling the Drosophila leg and wing. We find that both premotor networks cluster into modules that link MNs innervating muscles with related functions. Within most leg motor modules, the synaptic weights of each premotor neuron are proportional to the size of their target MNs, establishing a circuit basis for hierarchical MN recruitment. By contrast, wing premotor networks lack proportional synaptic connectivity, which may enable more flexible recruitment of wing steering muscles. Through comparison of the architecture of distinct motor control systems within the same animal, we identify common principles of premotor network organization and specializations that reflect the unique biomechanical constraints and evolutionary origins of leg and wing motor control.

DOI: 10.1038/s41586-024-07600-z

Source: https://www.nature.com/articles/s41586-024-07600-z