MouseLight Neuron AA0627

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. Researchers interested in the complete raw data set should contact Janelia to discuss obtaining it via hardware transfer.由贾内利亚（Janelia）科学家团队牵头的大规模神经示踪研究，将小鼠大脑中已完成完整示踪的神经元数量提升了一个数量级。研究人员如今可下载该数据集并进行三维浏览。 在小鼠大脑中，单个神经元会在左右大脑半球间蜿蜒穿行，编织出繁复的分支形态；研究人员此次还发现，它们甚至可延伸出长达45厘米的纤细纤维。 这是迄今已构建的最精细的小鼠大脑连接图谱，科学家可通过三维视图观察并探索这些游走的神经示踪轨迹。该图谱重构了小鼠大脑7000万个神经元中300余个的形态与位置。此前的同类神经元路径示踪研究，最多仅能完成数十个神经元的追踪工作。 研究人员采用双光子显微镜（two-photon microscopy）技术，通过迭代流程完成了经选择性标记的神经元的成像测绘。实验中将小鼠大脑切割为200微米厚的切片，每次可对数十个神经元进行标记并成像。每枚经成像的大脑样本可产生约50太字节（terabytes）的数据，其中包含已测绘的神经元信息，研究人员可通过NeuronBrowser应用进行浏览。 若有研究人员需要完整的原始数据集，可联系贾内利亚洽谈通过硬件传输获取该数据的相关事宜。