MouseLight Neuron AA1592

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团队开展的大规模神经追踪研究，将小鼠大脑中完全追踪的神经元数量提升了10倍。研究者现在可下载并以三维方式浏览这些数据。
小鼠大脑内，单个神经元呈Z字形跨越半球，形成复杂的分支模式；研究者还发现，这些神经元甚至能延伸出长达45厘米的细长纤维。科学家可在迄今最详尽的小鼠大脑连接图谱中，以三维方式观察和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多个神经元的形态和位置。此前追踪单个神经元路径的研究，最多仅完成了几十个神经元的追踪。
这些经选择性标记的神经元，是通过双光子显微镜（two-photon microscopy）结合迭代过程绘制而成的。研究人员将大脑切成200微米厚的切片，每次标记并成像几十个神经元。
每只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，可通过NeuronBrowser应用（网址：https://ml-neuronbrowser.janelia.org/）浏览。对完整原始数据集感兴趣的研究者，应联系Janelia，商议通过硬件传输获取数据的事宜。