Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Yeshiva University, Bronx, NY 10461, USA.
Brain Struct Funct. 2011 Sep;216(3):159-69. doi: 10.1007/s00429-011-0304-2. Epub 2011 Mar 9.
Neural circuits are organized into complex topographic maps. Although several neuroanatomical and genetic tools are available for studying circuit architecture, a limited number of methods exist for reliably revealing the global patterning of multiple topographic projections. Here we used wheat germ agglutinin (WGA) conjugated to Alexa 555 and 488 for dual color fluorescent mapping of parasagittal spinocerebellar topography in three dimensions. Using tissue section and wholemount imaging we show that WGA-Alexa tracers have three main characteristics that make them ideal tools for analyses of neural projection topography. First, the intense brightness of Alexa fluorophores allows multi-color imaging of patterned afferent projections in wholemount preparations. Second, WGA-Alexa tracers robustly label the entire trajectory of developing and adult projections. Third, long tracts such as the adult spinocerebellar tract can be traced in less than 6 h. Moreover, using WGA-Alexa tracers we resolved a level of complexity in the compartmentalized topography of the spinocerebellar projection map that has never before been appreciated. In summary, we introduce versatile tracers for rapidly labeling multiple topographic projections in three dimensions and uncover wiring complexities in the spinocerebellar map.
神经回路组织成复杂的地形图谱。尽管有几种神经解剖学和遗传学工具可用于研究电路结构，但可靠揭示多个地形投影的全局模式的方法数量有限。在这里，我们使用与 Alexa 555 和 488 缀合的麦胚凝集素 (WGA) 对三维矢状位脊髓小脑的地形进行双荧光标记。通过组织切片和整体成像，我们表明 WGA-Alexa 示踪剂具有三个主要特征，使其成为分析神经投射地形的理想工具。首先，Alexa 荧光团的高强度亮度允许在整体制剂中对模式传入投射进行多色成像。其次，WGA-Alexa 示踪剂可强烈标记发育中和成年投射的整个轨迹。第三，长束如成年脊髓小脑束可以在不到 6 小时内追踪。此外，使用 WGA-Alexa 示踪剂，我们解析了脊髓小脑投射图分区地形的复杂程度，这是以前从未被认识到的。总之，我们引入了多功能示踪剂，可快速标记三维的多个地形投射，并揭示脊髓小脑图中的布线复杂性。
