MouseLight Neuron AA0029

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）科研团队开展的大规模神经元追踪工作，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。
在小鼠大脑中，单个神经元会在脑区间蜿蜒穿行，编织出精巧的分支结构；研究团队此次还发现，这类神经元甚至可延伸出长达45厘米的纤细纤维。
此次构建的小鼠大脑连接组图谱是迄今最精细的相关图谱，科学家可在此三维环境中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300余个的形态与位置，而此前的神经元单路径追踪工作仅能完成数十个的量级。
此次研究通过双光子显微镜（two-photon microscopy）的迭代成像流程，对选择性标记的神经元进行成像定位。具体步骤为：将小鼠大脑切割为200微米的脑片，每次对数十个神经元进行标记并成像。每枚成像的大脑可产生约50太字节（terabytes）的数据，其中包含的已定位神经元可通过神经元浏览器（NeuronBrowser）应用进行浏览。若研究人员需获取完整的原始数据集，可联系贾内利亚（Janelia）协商通过硬件转移的方式获取。