School of Medicine, Tsinghua University, Beijing 100084, China.
IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing 100084, China.
Cell Rep Methods. 2021 Oct 1;1(6):100089. doi: 10.1016/j.crmeth.2021.100089. eCollection 2021 Oct 25.
Understanding brain functions requires detailed knowledge of long-range connectivity through which different areas communicate. A key step toward illuminating the long-range structures is to image the whole brain at synaptic resolution to trace axonal arbors of individual neurons to their termini. However, high-resolution brain-wide imaging requires continuous imaging for many days to sample over 10 trillion voxels, even in the mouse brain. Here, we have developed a sparse imaging and reconstruction tomography (SMART) system that allows brain-wide imaging of cortical projection neurons at synaptic resolution in about 20 h, an order of magnitude faster than previous methods. Analyses of morphological features reveal that single cortical neurons show remarkable diversity in local and long-range projections, with prefrontal, premotor, and visual neurons having distinct distribution of dendritic and axonal features. The fast imaging system and diverse projection patterns of individual neurons highlight the importance of high-resolution brain-wide imaging in revealing full neuronal morphology.
理解大脑功能需要详细了解不同区域通过长程连接进行通信的情况。阐明长程结构的关键步骤是在突触分辨率下对整个大脑进行成像，以追踪单个神经元的轴突树突到达其末端。然而，即使在小鼠大脑中，高分辨率的全脑成像也需要连续成像多天，以对超过 10 万亿体素进行采样。在这里，我们开发了一种稀疏成像和重建层析成像（SMART）系统，该系统可以在大约 20 小时内以突触分辨率对皮质投射神经元进行全脑成像，比以前的方法快一个数量级。形态特征分析表明，单个皮质神经元在局部和长程投射中表现出显著的多样性，前额叶、前运动和视觉神经元的树突和轴突特征分布具有明显的区别。快速成像系统和单个神经元的不同投射模式突出了高分辨率全脑成像在揭示完整神经元形态方面的重要性。
