MouseLight Neuron AA0366

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. <br>珍利亚（Janelia）研究团队开展的大规模神经示踪项目，将小鼠大脑中已完成全溯源的神经元数量提升了10倍。如今研究人员可下载并以三维视角浏览该数据集。 在小鼠大脑内部，单个神经元会在大脑半球间蜿蜒穿行，编织出繁复的分支形态；研究人员此次更发现，神经元甚至可延伸出长达45厘米的纤细纤维。 这是迄今已构建的最精细的小鼠大脑连接图谱，科学家可通过三维视图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300余个的形态与空间位置。此前的单神经元路径溯源研究，最多仅能完成数十个神经元的溯源工作。 研究团队采用双光子显微镜（two-photon microscopy）的迭代成像流程，对选择性标记的神经元进行了图谱构建。具体实验流程为：将小鼠大脑切割为200微米厚度的脑片，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太字节的数据，其中包含的已溯源神经元信息可通过NeuronBrowser应用程序进行浏览。若研究人员需要完整的原始数据集，可联系珍利亚（Janelia）商讨通过硬件传输的方式获取。