MouseLight Neuron AA0266

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. <br>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.<br>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. <br>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.

贾内莉亚（Janelia）科研团队开展的大规模神经示踪研究，将小鼠大脑中已完整示踪的神经元数量提升了10倍。研究人员如今可下载该数据集，并以三维视角浏览相关内容。
在小鼠大脑内，单个神经元会在左右脑半球间蜿蜒穿行，织就繁复的分支形态；此次研究还发现，神经元甚至可延伸出长达45厘米的纤细神经纤维。
科学家可在此次构建的迄今最精细的小鼠大脑连接图谱中，以三维形式查看并探索这些蜿蜒的神经示踪轨迹。该图谱重建了小鼠大脑7000万个神经元中300余个的形态与空间位置；此前的单神经元通路示踪研究，最多仅能完成数十个神经元的示踪工作。
此次研究采用双光子显微镜（two-photon microscopy）的迭代成像流程，对选择性标记的神经元进行图谱绘制：先将大脑切成200微米的薄片，每次标记数十个神经元并完成成像。每颗成像的大脑可产生约50太字节的数据，其中包含已完成示踪的神经元，研究人员可通过神经元浏览器（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，可联系贾内莉亚（Janelia）洽谈通过硬件传输方式获取数据的相关事宜。