MouseLight Neuron AA1427

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.

贾内利亚研究所（Janelia）的科学家团队开展了一项大规模神经示踪研究，将小鼠大脑中已完成全轨迹示踪的神经元数量提升至原有水平的10倍。如今研究人员可下载并以三维形式浏览该数据集。在小鼠大脑中，单个神经元会在左右脑半球间蜿蜒穿行，形成繁复精巧的分支结构；研究人员此次还发现，它们甚至能延伸出长达45厘米的纤细纤维。科研人员可通过这一迄今已构建的最精细的小鼠大脑连接图谱，以三维视角观察并探索这些蜿蜒延展的神经示踪轨迹。该图谱重建了小鼠大脑7000万神经元中超过300个的形态与位置，而此前的同类神经元轨迹示踪研究最多仅能完成数十个神经元的绘制。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定位绘制：实验中将大脑切成200微米厚的脑片，每次仅标记并成像数十个神经元。每一个成像的大脑样本可产生约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NeuronBrowser应用程序（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，可联系贾内利亚研究所协商通过硬件传输的方式获取。