MouseLight Neuron AA1150

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.

珍妮亚研究园区（Janelia）的科学家团队开展的大规模神经追踪研究，将小鼠大脑中已完成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。研究人员现已发现，小鼠大脑内的单个神经元可在左右脑半球间蜿蜒穿行，构建出繁复的分支形态，甚至能延伸出长达45厘米的纤细纤维。科学家可在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追踪轨迹。该图谱重构了小鼠大脑7000万个神经元中超过300个的形态与空间位置。此前针对单个神经元路径的追踪研究，最多仅能完成数十个神经元的追踪工作。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定位。实验中将小鼠大脑切成200微米厚的薄片，每次对数十个神经元进行标记并成像。每完成一个小鼠大脑的成像，可产生约50太字节的数据，其中包含已完成定位的神经元。研究人员可通过https://ml-neuronbrowser.janelia.org/的神经元浏览器（NeuronBrowser）应用浏览这些数据。若研究人员需要完整的原始数据集，可联系Janelia洽谈通过硬件传输获取数据的相关事宜。