MouseLight Neuron AA0451

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.

贾内利亚（Janelia）研究团队开展的大规模神经示踪研究，将小鼠大脑中已完成全示踪神经元（fully-traced neurons）的数量提升了10倍。如今研究人员可下载并三维浏览该数据集。
小鼠大脑内部，单个神经元会在大脑半球间蜿蜒穿行，呈现出如刺绣般的分支形态；研究人员新近还发现，此类神经元甚至可伸出长达45厘米的纤细纤维。
该研究绘制出了迄今已构建的最精细的小鼠大脑连接图谱，科学家可在三维空间中查看并探索这些蜿蜒的神经示踪结构。此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，此前的单个神经元通路示踪研究最多仅能完成数十个神经元的示踪。
研究人员通过迭代流程结合双光子显微镜（two-photon microscopy）技术，对经选择性标记的神经元进行成像：将大脑切成200微米厚的切片，每次标记数十个神经元并完成成像。每枚成像后的大脑可产生约50太字节（terabytes）的数据，其中包含的已映射神经元可通过神经元浏览器（NeuronBrowser）应用进行浏览。如需获取完整原始数据集，相关研究人员可联系贾内利亚（Janelia），通过硬件移交的方式协商获取事宜。