Rapid structural remodeling of peripheral taste neurons is independent of taste cell turnover.
Rapid structural remodeling of peripheral taste neurons is independent of taste cell turnover.
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DOI：
10.1371/journal.pbio.3002271
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发表时间：
2023-08
期刊：
影响因子：
9.8
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中科院分区：
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味蕾细胞在味蕾中不断被替换，因为旧细胞死亡，新细胞迁移到芽中。味觉的感知依赖于新的味蕾细胞与现有的神经回路的整合，但这些新细胞如何与味觉神经节神经元连接尚不清楚。味觉神经节神经元重塑以适应味蕾细胞的更新吗？如果是这样的话，味觉轴突的结构有多少是固定的，又有多少是重塑的？在这里，我们测量的运动和分支的个别味觉乔木（部分轴突支配味蕾）在小鼠随着时间的推移与双光子在体内显微镜。味蕾上的味觉乔木的末端分支在味蕾内持续快速地重塑。这种重塑比味蕾细胞更新预测的要快，同时增加和失去了末端分支。令人惊讶的是，用化学治疗剂阻断新味蕾细胞的进入揭示了味觉乔木上的末端分支的重塑不依赖于味蕾细胞的更新。虽然终端分支重塑是快速和内在控制，没有新的乔木被添加到味蕾，和一些失去超过100天。味觉神经节神经元保持稳定数量的乔木，每个都能够高速重塑。我们建议，终端分支可塑性允许乔木找到新的味蕾细胞，而稳定的乔木数量支持恒定的连接和功能的程度，随着时间的推移，为每个神经元。随着老细胞死亡和新细胞迁移到味蕾中，味蕾细胞在味蕾中不断被替换，但是这些新细胞如何与味觉神经节神经元连接？本研究使用活体双光子显微镜观察味蕾轴突的运动和分支，揭示了味蕾显著的结构可塑性。
Taste bud cells are constantly replaced in taste buds as old cells die and new cells migrate into the bud. The perception of taste relies on new taste bud cells integrating with existing neural circuitry, yet how these new cells connect with a taste ganglion neuron is unknown. Do taste ganglion neurons remodel to accommodate taste bud cell renewal? If so, how much of the structure of taste axons is fixed and how much remodels? Here, we measured the motility and branching of individual taste arbors (the portion of the axon innervating taste buds) in mice over time with two-photon in vivo microscopy. Terminal branches of taste arbors continuously and rapidly remodel within the taste bud. This remodeling is faster than predicted by taste bud cell renewal, with terminal branches added and lost concurrently. Surprisingly, blocking entry of new taste bud cells with chemotherapeutic agents revealed that remodeling of the terminal branches on taste arbors does not rely on the renewal of taste bud cells. Although terminal branch remodeling was fast and intrinsically controlled, no new arbors were added to taste buds, and few were lost over 100 days. Taste ganglion neurons maintain a stable number of arbors that are each capable of high-speed remodeling. We propose that terminal branch plasticity permits arbors to locate new taste bud cells, while stability of arbor number supports constancy in the degree of connectivity and function for each neuron over time. Taste bud cells are constantly replaced in taste buds as old cells die and new cells migrate into the bud, but how do these new cells connect with a taste ganglion neuron? This study uses in vivo two-photon microscopy to observe motility and branching of taste axon arbors, revealing remarkable structural plasticity in taste buds.