Adjacent Neuronal Fascicle Guides Motoneuron 24 Dendritic Branching and Axonal Routing Decisions through Dscam1 Signaling.
Adjacent Neuronal Fascicle Guides Motoneuron 24 Dendritic Branching and Axonal Routing Decisions through Dscam1 Signaling.
复制标题
相邻神经元束通过 Dscam1 信号传导引导运动神经元 24 树突分支和轴突路由决策。
DOI：
10.1101/2024.04.08.588591
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发表时间：
2024
期刊：
影响因子：
--
通讯作者：
Kamiyama,Daichi
中科院分区：
文献类型：
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作者：
Bui,KathyClara;Kamiyama,Daichi
轴突和树突的形成和精确定位对神经回路的发育至关重要。虽然已知通过细胞间接触的近胞嘧啶信号传导会影响这些过程，但中枢神经系统（CNS）内调节神经元过程定位的具体结构和机制仍有待充分确定。我们研究了果蝇胚胎中枢神经系统中的运动神经元24 (MN24)，其特征是一个复杂而刻板的轴突投射模式，称为轴突路由。在这个运动神经元中，初级树突状分支向中线横向突出，特别是出现在轴突转向的地方。我们观察到scp2阳性神经元参与了靠近MN24树突的腹侧神经索（VNC）侧束结构。值得注意的是，敲除唐氏综合征细胞粘附分子（dscam1）会导致MN24中树突的丢失和正常轴突路线的中断，而不影响束状结构的形成。通过dscam1的细胞型特异性敲除和修复实验，我们确定了MN24和scp2阳性束的相互作用，dscam1介导，促进了树突和轴突路线的发展。我们的研究结果表明，单个运动神经元内的神经元结构的整体结构，如轴突和树突，可以通过与相邻神经元束的局部接触来控制，神经元束是神经回路布线的一种新的参考结构。
The formation and precise positioning of axons and dendrites are crucial for the development of neural circuits. Although juxtracrine signaling via cell-cell contact is known to influence these processes, the specific structures and mechanisms regulating neuronal process positioning within the central nervous system (CNS) remain to be fully identified. Our study investigates motoneuron 24 (MN24) in the Drosophila embryonic CNS, which is characterized by a complex yet stereotyped axon projection pattern, known as axonal routing. In this motoneuron, the primary dendritic branches project laterally toward the midline, specifically emerging at the sites where axons turn. We observed that Scp2-positive neurons contribute to the lateral fascicle structure in the ventral nerve cord (VNC) near MN24 dendrites. Notably, the knockout of the Down syndrome cell adhesion molecule (dscam1) results in the loss of dendrites and disruption of proper axonal routing in MN24, while not affecting the formation of the fascicle structure. Through cell-type specific knockdown and rescue experiments of dscam1, we have determined that the interaction between MN24 and Scp2-positive fascicle, mediated by Dscam1, promotes the development of both dendrites and axonal routing. Our findings demonstrate that the holistic configuration of neuronal structures, such as axons and dendrites, within single motoneurons can be governed by local contact with the adjacent neuron fascicle, a novel reference structure for neural circuitry wiring.