Lesser Ellen, Moussa Anthony, Tuthill John C
Department of Neurobiology and Biophysics, University of Washington.
bioRxiv. 2025 Jun 1:2025.05.29.656810. doi: 10.1101/2025.05.29.656810.
Recent advances in electron microscopy (EM) and automated image segmentation have produced synaptic wiring diagrams of the central nervous system. A limitation of existing fly connectome datasets is that most sensory neurons are excised during sample preparation, creating a gap between the central and peripheral nervous systems. Here, we bridge this gap by reconstructing wing sensory axons from the Female Adult Nerve Cord (FANC) EM dataset and mapping them to peripheral sensory structures using genetic tools and light microscopy. We confirm the location and identity of known wing mechanosensory neurons and identify previously uncharacterized axons, including a novel population of putative proprioceptors that make monosynaptic connections onto wing steering motor neurons. We also find that proprioceptors of adjacent campaniform sensilla on the wing have distinct axon morphologies and postsynaptic partners, suggesting a high degree of specialization in axon pathfinding and synaptic partner matching. The peripheral location and central projections of wing sensory neurons are stereotyped across flies, allowing this wing proprioceptor atlas and genetic toolkit to guide analysis of other fly connectome datasets.
电子显微镜（EM）和自动图像分割技术的最新进展已生成中枢神经系统的突触连接图。现有果蝇连接组数据集的一个局限性在于，大多数感觉神经元在样本制备过程中被切除，从而在中枢神经系统和外周神经系统之间形成了一个间隙。在这里，我们通过从雌性成体神经索（FANC）EM数据集中重建翅感觉轴突，并使用遗传工具和光学显微镜将它们映射到外周感觉结构，来弥合这一间隙。我们确认了已知翅机械感觉神经元的位置和身份，并鉴定出先前未表征的轴突，包括一群新的假定本体感受器，它们与翅转向运动神经元形成单突触连接。我们还发现，翅上相邻钟形感器的本体感受器具有不同的轴突形态和突触后伙伴，这表明在轴突寻路和突触伙伴匹配方面具有高度的特异性。翅感觉神经元的外周位置和中枢投射在果蝇中是定型的，这使得这个翅本体感受器图谱和遗传工具包能够指导对其他果蝇连接组数据集的分析。
