Department of Biological Structure, University of Washington, Seattle, Washington 98195; email:
Solomon H. Snyder Department of Neuroscience, Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205; email:
Annu Rev Neurosci. 2017 Jul 25;40:395-424. doi: 10.1146/annurev-neuro-072116-031607. Epub 2017 Apr 26.
The retina is a tremendously complex image processor, containing numerous cell types that form microcircuits encoding different aspects of the visual scene. Each microcircuit exhibits a distinct pattern of synaptic connectivity. The developmental mechanisms responsible for this patterning are just beginning to be revealed. Furthermore, signals processed by different retinal circuits are relayed to specific, often distinct, brain regions. Thus, much work has focused on understanding the mechanisms that wire retinal axonal projections to their appropriate central targets. Here, we highlight recently discovered cellular and molecular mechanisms that together shape stereotypic wiring patterns along the visual pathway, from within the retina to the brain. Although some mechanisms are common across circuits, others play unconventional and circuit-specific roles. Indeed, the highly organized connectivity of the visual system has greatly facilitated the discovery of novel mechanisms that establish precise synaptic connections within the nervous system.
视网膜是一个极其复杂的图像处理器，包含众多细胞类型，这些细胞类型形成微电路，对视觉场景的不同方面进行编码。每个微电路都表现出独特的突触连接模式。负责这种模式形成的发育机制才刚刚开始被揭示。此外，不同视网膜回路处理的信号被传递到特定的、通常是不同的大脑区域。因此，许多工作都集中在理解将视网膜轴突投射到适当的中枢靶位的机制上。在这里，我们重点介绍最近发现的细胞和分子机制，这些机制共同塑造了视觉通路中从视网膜到大脑的刻板的布线模式。尽管一些机制在不同的回路中是通用的，但其他机制则发挥着非传统的和特定于回路的作用。事实上，视觉系统的高度组织连接极大地促进了对在神经系统内建立精确突触连接的新机制的发现。
