MouseLight Neuron AA1632

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.

珍妮莉亚（Janelia）的科学家团队开展的大规模神经示踪研究项目，将小鼠大脑中已完成完整示踪的神经元数量提升了一个数量级。研究人员现已可下载并三维浏览该数据集。在小鼠大脑中，单个神经元会在左右脑半球间蜿蜒穿行，形成精巧繁复的分支结构；研究人员此次还首次发现，神经元甚至可延伸出长达45厘米的纤细纤维。科研人员可在这张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。该图谱重建了小鼠大脑7000万个神经元中超过300个的形态与位置。此前的同类神经元路径示踪研究，最多仅能完成数十个神经元的追踪。研究团队通过双光子显微镜（two-photon microscopy）的迭代成像流程，对选择性标记的神经元进行了图谱绘制。实验中将大脑切割为200微米的切片，每次对数十个神经元进行标记并成像。每成像一个大脑可产生约50太字节（terabytes）的数据，其中包含已完成示踪的神经元信息，科研人员可通过NeuronBrowser应用（访问地址：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，可联系珍妮莉亚（Janelia）洽谈通过硬件传输的方式获取相关数据。