MouseLight Neuron AA0295

A vast neural tracing effort by a team of Janelia scientists has upped the number of fully-traced neurons in the mouse brain by a factor of 10. Researchers can now download and browse the data in three dimensions. Inside the mouse brain, individual neurons zigzag across hemispheres, embroider branching patterns and, researchers have now discovered, can even spool out spindly fibers up to 45 centimeters long.Scientists can see and explore these wandering neural traces in 3-D in the most detailed map of mouse brain wiring yet created. The map reconstructs the shape and position of more than 300 of the 70 million neurons in the mouse brain. Previous efforts to trace the path of individual neurons had topped out in the dozens. The selectively-labeled neurons were mapped in an iterative process with two-photon microscopy. The brain is sliced in 200-micron sections and a few dozen neurons are labeled at a time and imaged. Each brain imaged yields about 50 terabytes of data, each containing mapped neurons which can be browsed via the NeuronBrowser application. Researchers interested in the complete raw data set should contact Janelia to discuss obtaining it via hardware transfer.

贾努利亚（Janelia）研究团队开展的大规模神经示踪工作，将小鼠大脑中已完整示踪的神经元数量提升了10倍。如今，研究人员可下载并以三维形式浏览该数据集。
在小鼠大脑内，单个神经元会在左右脑区间蜿蜒穿行，织就繁复的分支结构；研究人员此次还新发现，这类神经元甚至能延伸出长达45厘米的纤细纤维。
这是迄今最为精细的小鼠大脑连接图谱，科学家可通过三维视图观察并探索这些蜿蜒的神经示踪结构。该图谱重构了小鼠大脑7000万个神经元中300余个的形态与空间位置。此前的同类神经元示踪研究，仅能完成数十个神经元的完整示踪。
研究团队采用双光子显微镜（two-photon microscopy）技术，通过迭代流程完成了选择性标记神经元的成像与绘制：将小鼠大脑切成200微米厚的切片，每次标记并成像数十个神经元。每枚成像的大脑可产生约50太字节（terabytes）的数据，其中包含已绘制完成的神经元，可通过NeuronBrowser应用程序进行浏览。
若有研究人员需要完整的原始数据集，可联系贾努利亚团队，通过硬件传输的方式洽谈获取事宜。