MouseLight Neuron AA0062

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. <br>

贾内利亚（Janelia）科研团队开展的大规模神经追踪工作，将小鼠大脑中已完成全轨迹追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，单个神经元会在大脑半球间蜿蜒穿行，构建出如刺绣般精致的分支结构；研究人员最新发现，它们甚至可延伸出长达45厘米的纤细纤维。
科学家可在这张迄今最精细的小鼠大脑连接图谱中，以三维视角观察并探索这些蜿蜒的神经轨迹。该图谱重构了小鼠大脑7000万神经元中超过300个的形态与位置。此前的同类神经元轨迹追踪研究，最多仅能完成数十个神经元的轨迹绘制。
研究人员借助双光子显微镜（two-photon microscopy）的迭代成像流程，完成了对选择性标记神经元的绘制工作。实验中将小鼠大脑切割为200微米厚的脑片，每次对数十个神经元进行标记并成像。每完成一个小鼠大脑的成像，可产生约50太字节（terabytes）的数据，每份数据均包含可通过NeuronBrowser应用程序浏览的已追踪神经元相关信息。若研究人员需要完整的原始数据集，可联系Janelia洽谈通过硬件移交的方式获取相关数据。