MouseLight Neuron AA0832

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.

贾内莉亚（Janelia）科研团队开展的大规模神经追踪研究，将小鼠大脑中已完成全追踪的神经元数量提升了10倍。目前研究人员可下载该数据集，并以三维形式进行浏览。小鼠大脑内的单个神经元会在脑区间蜿蜒穿行，形成如同刺绣般繁复的分支结构；此次研究还发现，这些神经元甚至能延伸出长达45厘米的纤细纤维。这是目前已构建的最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追踪结果。该图谱重构了小鼠大脑7000万个神经元中超过300个的形态与位置。此前的同类神经元追踪研究，仅能完成数十个神经元的全路径追踪。研究人员采用双光子显微镜（two-photon microscopy）的迭代成像流程，对选择性标记的神经元进行了测绘。实验中将小鼠大脑切成200微米厚的脑片，每次对数十个神经元进行标记并成像。每完成一个小鼠大脑的成像，可产生约50太字节的数据，每个数据集均包含已测绘的神经元信息，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，可联系贾内莉亚（Janelia）团队，通过硬件传输的方式洽谈获取事宜。