Plazaola-Sasieta Haritz, Fernández-Pineda Alejandra, Zhu Qi, Morey Marta
a Department of Genetics, Microbiology and Statistics ; School of Biology and Institute of Biomedicine of the University of Barcelona (IBUB), University of Barcelona , Barcelona , Spain.
J Neurogenet. 2017 Dec;31(4):231-249. doi: 10.1080/01677063.2017.1391249. Epub 2017 Oct 27.
The assembly of neural circuits relies on the accurate establishment of connections between synaptic partners. Precise wiring results from responses that neurons elicit to environmental cues and cell-cell contact events during development. A common design principle in both invertebrate and vertebrate adult nervous systems is the orderly array of columnar and layered synaptic units of certain neuropils. This similarity is particularly striking in the visual system, both at the structural and cell-type levels. Given the powerful genetic approaches and tools available in Drosophila, the fly visual system has been extensively used to probe how specific wiring patterns are achieved during development. In this review, we cover the developmental principles and molecular strategies that govern the assembly of columnar units (lamina cartridges and medulla columns), the formation of layers, afferent specific layer selection, and synaptogenesis in Drosophila. The mechanisms include: sequential developmental steps that ensure coordinated assembly of synaptic partners; anterograde and autocrine signaling; interactions between cell-surface molecules, or secreted molecules and their receptors that take place among neurons; and glia signaling to neurons.
神经回路的组装依赖于突触伙伴之间连接的准确建立。精确的布线源于神经元在发育过程中对环境线索和细胞间接触事件所产生的反应。在无脊椎动物和脊椎动物的成体神经系统中，一个共同的设计原则是某些神经纤维的柱状和分层突触单元的有序排列。这种相似性在视觉系统中尤为显著，无论是在结构层面还是细胞类型层面。鉴于果蝇中可用的强大遗传方法和工具，果蝇视觉系统已被广泛用于探究在发育过程中如何实现特定的布线模式。在这篇综述中，我们涵盖了果蝇中控制柱状单元（薄板盒和髓质柱）组装、层的形成、传入特定层选择以及突触形成的发育原理和分子策略。这些机制包括：确保突触伙伴协调组装的连续发育步骤；顺行和自分泌信号传导；神经元之间发生的细胞表面分子、分泌分子及其受体之间的相互作用；以及胶质细胞向神经元的信号传导。
