2025年9月17日，华盛顿大学TJohn C. Tuthill小组在《自然》杂志发表论文，宣布他们研究出果蝇腿本体感觉的突触前选择性抑制。

通过对行为果蝇的钙成像研究，该研究组发现编码位置的腿部本体感受器轴突在一系列行为中都是活跃的，而编码运动的腿部本体感受器轴突在行走和梳理过程中是被抑制的。利用连接组学，课题组研究人员确定了一类特定的中间神经元，它们对运动编码本体感受器的轴突提供GABA能突触前抑制。这些中间神经元接收来自平行的兴奋性和抑制性下行通路的输入，这些下行通路以特定环境和特定腿部的方式驱动中间神经元。来自中间神经元及其下行输入的钙成像证实，它们的活动与自我产生的腿部运动有关，而不是被动的。综上所述，他们的发现揭示了在自我产生的运动中抑制特定本体感觉反馈信号的神经回路。

研究人员表示，控制手臂和腿需要来自本体感觉神经元的反馈，这些神经元可以检测关节的位置和运动。本体感觉反馈可以针对不同的行为环境进行调整，但其潜在的回路机制尚不清楚。

附：英文原文

Title: Selective presynaptic inhibition of leg proprioception in behaving Drosophila

Author: Dallmann, Chris J., Luo, Yichen, Agrawal, Sweta, Mamiya, Akira, Chou, Grant M., Cook, Andrew, Sustar, Anne, Brunton, Bingni W., Tuthill, John C.

Issue&Volume: 2025-09-17

Abstract: Controlling arms and legs requires feedback from the proprioceptive sensory neurons that detect joint position and movement1,2. Proprioceptive feedback must be tuned for different behavioural contexts3,4,5,6, but the underlying circuit mechanisms remain poorly understood. Here, using calcium imaging in behaving Drosophila, we find that the axons of position-encoding leg proprioceptors are active across a range of behaviours, whereas the axons of movement-encoding leg proprioceptors are suppressed during walking and grooming. Using connectomics7,8,9, we identify a specific class of interneurons that provide GABAergic presynaptic inhibition to the axons of movement-encoding proprioceptors. These interneurons receive input from parallel excitatory and inhibitory descending pathways that are positioned to drive the interneurons in a context-specific and leg-specific manner. Calcium imaging from both the interneurons and their descending inputs confirms that their activity is correlated with self-generated but not passive leg movements. Taken together, our findings reveal a neural circuit that suppresses specific proprioceptive feedback signals during self-generated movements.

DOI: 10.1038/s41586-025-09554-2

Source: https://www.nature.com/articles/s41586-025-09554-2