MouseLight Neuron AA0041

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.贾内利亚研究园区（Janelia）的科学家团队开展了一项大规模神经示踪（neural tracing）研究，将小鼠大脑中已完整示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形式浏览该数据集。 在小鼠大脑中，单个神经元会在左右脑半球间蜿蜒穿行，构建出繁复的分支结构；研究人员此次还首次发现，它们甚至能延伸出长达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组图谱中，以三维形式观察并探索这些蜿蜒穿行的神经示踪痕迹。该图谱重建了小鼠大脑7000万个神经元中超过300个的形态与位置。此前的单个神经元示踪研究最多仅能完成数十个神经元的追踪工作。 此次研究采用迭代流程结合双光子显微镜（two-photon microscopy）技术，对选择性标记的神经元进行成像绘制。实验中将大脑切割为200微米厚度的切片，每次对数十个神经元进行标记并成像。每一个被成像的大脑可产生约50太字节的数据，其中包含已完成绘制的神经元，研究人员可通过NeuronBrowser应用程序进行浏览。若有研究人员希望获取完整的原始数据集，可联系贾内利亚研究园区（Janelia）商议通过硬件传输的方式获取该数据。