MouseLight Neuron AA1566

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.

Janelia机构的科学家团队开展了一项大规模神经追踪（neural tracing）工作，将小鼠大脑中完全追踪的神经元数量提升了10倍。研究人员如今可下载并以三维方式浏览该数据。

在小鼠大脑内部，单个神经元在半球间呈Z字形穿梭，勾勒出如刺绣般繁复的分支图案——研究人员新近发现，它们甚至能延伸出纤细的纤维丝，最长可达45厘米。科学家们可在这张迄今最详尽的小鼠大脑连接组（mouse brain wiring）三维图谱中，观察并探索这些游走的神经轨迹。

该图谱重构了小鼠大脑7000万个神经元中300多个的形态与位置。此前追踪单个神经元路径的尝试，最多仅完成数十个。

这些选择性标记的神经元（selectively-labeled neurons）通过双光子显微镜（two-photon microscopy）以迭代流程完成图谱构建。大脑被切成200微米厚的切片，每次标记并成像数十个神经元。

每颗成像大脑产生约50TB的数据，其中包含已绘制的神经元，可通过NeuronBrowser应用程序（网址：https://ml-neuronbrowser.janelia.org/）浏览。

对完整原始数据集感兴趣的研究人员，可联系Janelia机构，商议通过硬件传输获取该数据集。