Department of Physiology and Biophysics, University of Washington, Seattle, United States.
School of Natural Sciences, Bangor University, Bangor, United Kingdom.
Elife. 2020 Dec 2;9:e60299. doi: 10.7554/eLife.60299.
Proprioception, the sense of self-movement and position, is mediated by mechanosensory neurons that detect diverse features of body kinematics. Although proprioceptive feedback is crucial for accurate motor control, little is known about how downstream circuits transform limb sensory information to guide motor output. Here we investigate neural circuits in that process proprioceptive information from the fly leg. We identify three cell types from distinct developmental lineages that are positioned to receive input from proprioceptor subtypes encoding tibia position, movement, and vibration. 13Bα neurons encode femur-tibia joint angle and mediate postural changes in tibia position. 9Aα neurons also drive changes in leg posture, but encode a combination of directional movement, high frequency vibration, and joint angle. Activating 10Bα neurons, which encode tibia vibration at specific joint angles, elicits pausing in walking flies. Altogether, our results reveal that central circuits integrate information across proprioceptor subtypes to construct complex sensorimotor representations that mediate diverse behaviors, including reflexive control of limb posture and detection of leg vibration.
本体感觉是对自身运动和位置的感知，由机械感觉神经元介导，这些神经元可以检测身体运动学的各种特征。尽管本体感觉反馈对于精确的运动控制至关重要，但对于下游电路如何将肢体感觉信息转化为指导运动输出知之甚少。在这里，我们研究了 中处理蝇腿本体感觉信息的神经回路。我们从不同的发育谱系中鉴定出三种细胞类型，它们的位置可以接收编码胫骨位置、运动和振动的本体感受器亚型的输入。13Bα 神经元编码股骨-胫骨关节角度，并介导胫骨位置的姿势变化。9Aα 神经元也驱动腿部姿势的变化，但编码方向运动、高频振动和关节角度的组合。激活编码特定关节角度胫骨振动的 10Bα 神经元会导致正在行走的苍蝇停止。总的来说，我们的研究结果表明，中枢回路整合了不同本体感受器亚型的信息，构建了复杂的感觉运动表征，介导了多种行为，包括肢体姿势的反射控制和腿部振动的检测。
