Department of Applied Biochemistry, School of Engineering, Tokai University, Kitakaname, Hiratsuka, Kanagawa 259-1292, Japan.
J Struct Biol. 2013 Nov;184(2):271-9. doi: 10.1016/j.jsb.2013.08.012. Epub 2013 Sep 4.
The first step to understanding brain function is to determine the brain's network structure. We report a three-dimensional analysis of the brain network of the fruit fly Drosophila melanogaster by synchrotron-radiation tomographic microscopy. A skeletonized wire model of the left half of the brain network was built by tracing the three-dimensional distribution of X-ray absorption coefficients. The obtained models of neuronal processes were classified into groups on the basis of their three-dimensional structures. These classified groups correspond to neuronal tracts that send long-range projections or repeated structures of the optic lobe. The skeletonized model is also composed of neuronal processes that could not be classified into the groups. The distribution of these unclassified structures correlates with the distribution of contacts between neuronal processes. This suggests that neurons that cannot be classified into typical structures should play important roles in brain functions. The quantitative description of the brain network provides a basis for structural and statistical analyses of the Drosophila brain. The challenge is to establish a methodology for reconstructing the brain network in a higher-resolution image, leading to a comprehensive understanding of the brain structure.
理解大脑功能的第一步是确定大脑的网络结构。我们通过同步辐射断层显微镜报告了对果蝇大脑网络的三维分析。通过追踪 X 射线吸收系数的三维分布，构建了左半脑网络的骨架化线模型。根据三维结构对获得的神经元过程模型进行分类，这些分类组对应于发送远程投射或光叶重复结构的神经元束。骨架化模型还由无法分类到组中的神经元过程组成。这些未分类结构的分布与神经元过程之间的接触分布相关。这表明无法分类到典型结构的神经元应该在大脑功能中发挥重要作用。大脑网络的定量描述为果蝇大脑的结构和统计分析提供了基础。挑战在于建立一种在更高分辨率图像中重建大脑网络的方法，从而全面了解大脑结构。
