MouseLight Neuron AA0712

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.

贾内莉亚（Janelia）研究团队开展的大规模神经示踪研究，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以三维形式浏览该数据集。
在小鼠大脑中，单个神经元会在大脑半球间蜿蜒穿行，形成如刺绣般繁复的分支结构；研究人员此次更发现，神经元甚至可延伸出长达45厘米的纤细纤维。
科学家可通过这一迄今已构建的最精细小鼠大脑连接图谱，以三维视角观察并探索这些蜿蜒分布的神经示踪结果。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，而此前的神经元路径示踪研究仅能完成数十个神经元的示踪工作。
该研究通过结合双光子显微镜（two-photon microscopy）的迭代成像流程，对选择性标记的神经元进行成像绘制。首先将小鼠大脑切割为200微米厚度的脑片，每次可对数十个神经元进行标记并成像。每完成一个大脑的成像，将产生约50太字节的数据，每份数据均包含已示踪的神经元信息，可通过NeuronBrowser应用程序进行浏览。若研究人员需获取完整原始数据集，可联系贾内莉亚（Janelia）商讨通过硬件传输方式获取的相关事宜。