MouseLight Neuron AA0995

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.

贾内利亚（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三维浏览该数据集。在小鼠大脑内部，单个神经元会在左右脑半球间蜿蜒穿行，形成如刺绣般精巧的分支结构；研究人员最新发现，这类神经元甚至可延伸出长达45厘米的纤细纤维。该数据集是目前已构建的最精细小鼠大脑连接图谱，科学家可通过三维视角观察并探索这些蜿蜒的神经示踪结果。此图谱重构了小鼠大脑7000万个神经元中超过300个的形态与位置，而此前的单个神经元示踪研究仅能完成数十个神经元的示踪。该研究通过双光子显微镜（two-photon microscopy）的迭代成像流程，对选择性标记的神经元进行绘制。具体步骤为：将大脑切割为200微米的切片，每次标记数十个神经元并完成成像。每枚成像的大脑可产生约50太字节的数据，其中包含已绘制的神经元信息，研究人员可通过神经元浏览器（NeuronBrowser）应用程序进行浏览。若有研究人员需要完整的原始数据集，请联系贾内利亚（Janelia）团队，通过硬件转移的方式协商获取事宜。