title: Connectomics: comprehensive approaches for whole-brain mapping.
abstract: The aim of connectomics analysis is to understand whole-brain neural connections. This is accomplished using new biotechnologies. Here, we provide an overview of the recent progress in connectomics analysis. The entire neural network of an organism was revealed for the first time in the nematode. Caenorhabditis elegans (C. elegans) have an advantage of their limited number of neurons and their transparency, allowing the neural network to be visualized using light and electron microscopes (EMs). It is practically impossible to adopt the same approach for mammals because of the large number of neural cells and the opacity of the central nervous system. A variety of new technologies are being developed to perform computer-assisted high-throughput image acquisition and analysis to obtain whole-brain maps for higher species, including mammals. Diffusion tensor magnetic resonance imaging and tractography and three-dimensional imaging with the EM are examples of novel approaches to connectomics. These new technologies will soon be applied not only to Drosophila, C. elegans and rodent research, but also to comprehensive connectomics analysis in a wide range of species including humans and primates. In the near future, results from connectomics analysis will reveal the neural circuitry of the whole brain and enhance our understanding of the human mind and neuropsychiatric diseases.
authors.affiliation: Department of Physiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan shibata@2001.jukuin.keio.ac.jp hidokano@a2.keio.jp.
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Shibata
authors.affiliation: Department of Physiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan Central Institute for Experimental Animals, Tonomachi 3-25-12, Kawasaki-ku, Kawasaki, Kanagawa 210-0821, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Komaki
authors.affiliation: Department of Physiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan.
authors.forename: Fumiko
authors.initials: F
authors.lastname: Seki
authors.affiliation: Department of Physiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan.
authors.forename: Michiko O
authors.initials: MO
authors.lastname: Inouye
authors.affiliation: Electron Microscope Laboratory, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan.
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Nagai
authors.affiliation: Department of Physiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan Laboratory for Marmoset Neural Architecture, RIKEN Brain Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan shibata@2001.jukuin.keio.ac.jp hidokano@a2.keio.jp.
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Okano
mesh_terms: D000818:Animals; D001921:Brain / Q000648:ultrastructure*; D017173:Caenorhabditis elegans / Q000648:ultrastructure; D063132:Connectome / Q000379:methods*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods; D004330:Drosophila / Q000648:ultrastructure; D023281:Genomics / Q000379:methods; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D016571:Neural Networks, Computer; D009474:Neurons / Q000648:ultrastructure
keywords: brain mapping; connectome; connectomics; electron microscope; magnetic resonance imaging; serial EM