MouseLight Neuron AL0003

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 at https://ml-neuronbrowser.janelia.org/. Researchers interested in the complete raw data set should contact Janelia to discuss obtaining it via hardware transfer.

贾内利亚研究所（Janelia）科研团队开展的大规模神经追踪研究，将小鼠大脑中已完整追踪的神经元数量提升了10倍。如今研究人员可下载并三维浏览该数据集。
研究人员此次发现，小鼠大脑内的单个神经元不仅会在左右脑半球间蜿蜒穿行，织就繁复的分支结构，甚至可延伸出长达45厘米的细长纤维。科研人员可通过这一迄今最精细的小鼠大脑连接图谱，以三维形式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。此前的同类神经元路径追踪研究，最多仅能完成数十个神经元的追踪。
研究人员采用双光子显微镜（two-photon microscopy）技术，通过迭代流程对选择性标记的神经元进行成像绘制。实验中将小鼠大脑切成200微米厚的切片，每次仅标记并成像数十个神经元。
每枚成像的大脑样本可产生约50太字节的数据，其中包含已完成绘制的神经元，研究人员可通过https://ml-neuronbrowser.janelia.org/的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，可联系贾内利亚研究所洽谈通过硬件传输方式获取的相关事宜。