MouseLight Neuron AA1399

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.

贾内利亚（Janelia）研究团队的科学家开展了一项大规模神经示踪研究项目，将小鼠大脑中已完整示踪的神经元数量提升了一个数量级。如今，研究人员可下载并以三维形式浏览该数据集。在小鼠大脑内部，单个神经元会在双侧脑半球间蜿蜒穿行，形成精巧的分支构型；研究人员新近还发现，这类神经元甚至可延伸出长达45厘米的纤细神经纤维。借助迄今最为精细的小鼠大脑连接组图谱，科学家们可三维观察并探索这些蜿蜒延展的神经示踪结构。该图谱重建了小鼠大脑7000万总神经元中逾300个的形态与空间位置。此前的神经元路径示踪研究，最多仅能完成数十个神经元的完整示踪。本次研究中，经选择性标记的神经元通过双光子显微镜（two-photon microscopy）的迭代成像流程完成标注与成像：大脑样本被切割为200微米厚度的切片，每次仅标记并成像数十个神经元。每一块成像的大脑样本可产生约50太字节（terabytes）的数据，其中包含的已标注神经元可通过https://ml-neuronbrowser.janelia.org/的NeuronBrowser应用程序进行浏览。若研究人员需要获取完整的原始数据集，可联系贾内利亚研究所商讨通过硬件传输的方式获取相关数据。