Department of Physiology, McGill University, Montreal, QC, Canada.
Front Neural Circuits. 2020 Aug 6;14:44. doi: 10.3389/fncir.2020.00044. eCollection 2020.
During development, neurons navigate a tangled thicket of thousands of axons and dendrites to synapse with just a few specific targets. This phenomenon termed wiring specificity, is critical to the assembly of neural circuits and the way neurons manage this feat is only now becoming clear. Recent studies in the mouse retina are shedding new insight into this process. They show that specific wiring arises through a series of stages that include: directed axonal and dendritic growth, the formation of neuropil layers, positioning of such layers, and matching of co-laminar synaptic partners. Each stage appears to be directed by a distinct family of recognition molecules, suggesting that the combinatorial expression of such family members might act as a blueprint for retinal connectivity. By reviewing the evidence in support of each stage, and by considering their underlying molecular mechanisms, we attempt to synthesize these results into a wiring model which generates testable predictions for future studies. Finally, we conclude by highlighting new optical methods that could be used to address such predictions and gain further insight into this fundamental process.
在发育过程中，神经元在数千个轴突和树突的纠结灌木丛中导航，只与少数几个特定的目标形成突触。这种现象称为连接特异性，对神经回路的组装至关重要，而神经元如何完成这一壮举现在才开始变得清晰。最近在老鼠视网膜的研究为这一过程提供了新的见解。它们表明，特定的布线是通过一系列阶段产生的，包括：定向轴突和树突生长、神经胶层的形成、这种层的定位以及共层突触伙伴的匹配。每个阶段似乎都由一组不同的识别分子指导，这表明这些家族成员的组合表达可能充当视网膜连接的蓝图。通过回顾支持每个阶段的证据，并考虑其潜在的分子机制，我们试图将这些结果综合成一个布线模型，为未来的研究提出可测试的预测。最后，我们通过强调新的光学方法来结束讨论，这些方法可以用来解决这些预测，并进一步深入了解这一基本过程。
