Three-dimensional network of Drosophila brain hemisphere

Abstract

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.

Genetically targeted 3D visualisation of Drosophila neurons under Electron Microscopy and X-Ray Microscopy using miniSOG

“…From these scans, many features were recognisable. Images were similar to those obtained from light microscopy and from scans using synchrotron-based X-ray sources5152, respectively (Fig. 4b).…”

Imitating the brain with neurocomputer a “new” way towards artificial general intelligence

“…According the opinion of the experts of the workshop, "within a decade, we expect to have addressed this challenge in brains including but not limited to drosophila, zebrafish, mouse, and marmoset, and to have developed tools to conduct massive neurocartographic analyses" [81] . As if to prove the expectation, half year later, Ryuta Mizutani and Pals at Tokai University in Japan complete an accurate 3D map of a drosophila brain s neural network, with about 100 K neurons [82] .…”

Cutting‐edge morphological studies of post‐mortem brains of patients with schizophrenia and potential applications of X‐ray nanotomography (nano‐CT)

“…As heavy (high‐Z) elements strongly interact with X‐rays, the target constituents can be labeled with high‐Z elements in the X‐ray image . Neuronal structures of the stained tissues have been visualized with X‐ray microtomography (micro‐CT) and nanotomography (nano‐CT) by using synchrotron radiation sources . In the analysis of the neuronal structure of schizophrenia cases described below, brain tissue samples were stained with silver by using the Golgi impregnation so that the neurons were visible in the X‐ray image .…”

“…Instead, structural parameters should be extracted from the 3‐D image by evaluating the structure quantitatively. Such parameters can be calculated from Cartesian coordinate models of neurons built from the 3‐D image …”

“…68,69 Neuronal structures of the stained tissues have been visualized with X-ray microtomography (micro-CT) and nanotomography (nano-CT) by using synchrotron radiation sources. 44,[68][69][70][71][72][73][74] In the analysis of the neuronal structure of schizophrenia cases described below, brain tissue samples were stained with silver by using the Golgi impregnation so that the neurons were visible in the X-ray image. 44 The advantages of X-ray micro-CT or nano-CT are that: (i) the inner structures of even opaque samples can be visualized; (ii) the 3-D image exhibits isotropic resolution; and (iii) the visualization process does not distort the image.…”