MouseLight Neuron AA1545

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，将小鼠大脑中已完全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。在小鼠大脑中，单个神经元可穿梭于大脑半球之间，构建出繁复的分支形态；研究人员此次还发现，神经元甚至能延伸出长达45厘米的细长纤维。研究人员可在这一迄今最精细的小鼠大脑连接图谱中，以三维形式观察并探索这些蜿蜒的神经示踪轨迹。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；此前的单个神经元示踪研究最多仅能完成数十个神经元的示踪。研究人员采用双光子显微镜（two-photon microscopy）结合迭代成像流程，对选择性标记的神经元进行了成像绘制。实验中将大脑切割为200微米厚的脑片，每次对数十个神经元进行标记并成像。每例成像的大脑可产生约50太字节（terabytes）的数据，其中包含已完成绘制的神经元信息，研究人员可通过NeuronBrowser应用（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，可联系贾努利亚团队商讨通过硬件传输的方式获取该数据。