Guo Zengcai V, Hart Anne C, Ramanathan Sharad
Harvard University, Cambridge, Massachusetts, USA.
Nat Methods. 2009 Dec;6(12):891-6. doi: 10.1038/nmeth.1397. Epub 2009 Nov 8.
The nematode Caenorhabditis elegans has a compact nervous system with only 302 neurons. Whereas most of the synaptic connections between these neurons have been identified by electron microscopy serial reconstructions, functional connections have been inferred between only a few neurons through combinations of electrophysiology, cell ablation, in vivo calcium imaging and genetic analysis. To map functional connections between neurons, we combined in vivo optical stimulation with simultaneous calcium imaging. We analyzed the connections from the ASH sensory neurons and RIM interneurons to the command interneurons AVA and AVD. Stimulation of ASH or RIM neurons using channelrhodopsin-2 (ChR2) resulted in activation of AVA neurons, evoking an avoidance behavior. Our results demonstrate that we can excite specific neurons expressing ChR2 while simultaneously monitoring G-CaMP fluorescence in several other neurons, making it possible to rapidly decipher functional connections in C. elegans neural circuits.
线虫秀丽隐杆线虫拥有一个仅由302个神经元组成的紧凑神经系统。尽管这些神经元之间的大多数突触连接已通过电子显微镜连续重建得以确定，但仅通过电生理学、细胞消融、体内钙成像和遗传分析的组合，才推断出少数神经元之间的功能连接。为了绘制神经元之间的功能连接图谱，我们将体内光学刺激与同步钙成像相结合。我们分析了从ASH感觉神经元和RIM中间神经元到指令中间神经元AVA和AVD的连接。使用通道视紫红质-2（ChR2）刺激ASH或RIM神经元会导致AVA神经元激活，引发回避行为。我们的结果表明，我们可以在同时监测其他几个神经元中G-CaMP荧光的情况下，激发表达ChR2的特定神经元，从而有可能快速解读秀丽隐杆线虫神经回路中的功能连接。
