MouseLight Neuron AA1283

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）的科研团队开展了一项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以三维形式浏览该数据集。在小鼠大脑中，单个神经元会在脑区间蜿蜒穿行，编织出繁复的分支形态；研究团队此次还发现，神经元甚至可延伸出长达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，研究人员可通过该图谱以三维形式观察、探索这些蜿蜒延伸的神经追踪结果。该图谱重建了小鼠大脑7000万神经元中超过300个的形态与位置，而此前的同类研究仅能完成数十个神经元的路径追踪。研究人员通过双光子显微镜（two-photon microscopy）的迭代成像流程，对经选择性标记的神经元进行了绘图。实验中将大脑切成200微米的薄片，每次对数十个神经元进行标记并成像。每一个被成像的大脑可产生约50太字节的数据，其中包含已完成绘图的神经元，研究人员可通过NeuronBrowser应用程序（https://ml-neuronbrowser.janelia.org/）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，通过硬件转移的方式洽谈获取事宜。