National Institute of Genetics 4 articles published in JoVE Neuroscience Optogenetic Phase Transition of TDP-43 in Spinal Motor Neurons of Zebrafish Larvae Kazuhide Asakawa1, Hiroshi Handa1, Koichi Kawakami2,3 1Department of Chemical Biology, Tokyo Medical University, 2Division of Molecular and Developmental Biology, National Institute of Genetics, 3Department of Genetics, Graduate University for Advanced Studies (SOKENDAI) We describe a protocol to induce phase transition of TAR DNA-binding protein 43 (TDP-43) by light in the spinal motor neurons using zebrafish as a model. Environment Microfocus X-ray CT (microCT) Imaging of Actinia equina (Cnidaria), Harmothoe sp. (Annelida), and Xenoturbella japonica (Xenacoelomorpha) Akiteru Maeno1, Hisanori Kohtsuka2, Kensuke Takatani3, Hiroaki Nakano3 1Mammalian Genetics Laboratory, National Institute of Genetics, 2Misaki Marine Biological Station, The University of Tokyo, 3Shimoda Marine Research Center, University of Tsukuba Here, protocols for performing microfocus X-ray computed tomography (microCT) imaging of three marine invertebrate animals are explained in detail. This study describes steps such as sample fixation, staining, mounting, scanning, image reconstruction, and data analyses. Suggestions on how the protocol can be adjusted for different samples are also provided. Neuroscience In Vivo Two-photon Imaging of Cortical Neurons in Neonatal Mice Hidenobu Mizuno1,2,3, Shingo Nakazawa2,3, Takuji Iwasato2,3 1International Research Center for Medical Sciences (IRCMS), Kumamoto University, 2Division of Neurogenetics, National Institute of Genetics, 3Department of Genetics, SOKENDAI (The Graduate University for Advanced Studies) We present an in vivo two-photon imaging protocol for imaging the cerebral cortex of neonatal mice. This method is suitable for analyzing the developmental dynamics of cortical neurons, the molecular mechanisms that control the neuronal dynamics, and the changes in neuronal dynamics in disease models. Behavior Measuring Active and Passive Tameness Separately in Mice Hiromichi Nagayama1,2, Yuki Matsumoto1,2, Akira Tanave1, Motoko Nihei1, Tatsuhiko Goto3, Tsuyoshi Koide1,2 1Mouse Genomics Resource Laboratory, National Institute of Genetics, 2Department of Genetics, SOKENDAI (The Graduate University for Advanced Studies), 3Research Center for Global Agromedicine, Obihiro University of Agriculture and Veterinary Medicine Tameness in animals includes a reduction of avoidance responses to humans (passive tameness) and an increase in active approaches to humans (active tameness). Here, we describe detailed protocols for three behavioral tests (active tameness, passive tameness, and stay-on-hand tests) to separately measure the active and passive tameness of mice.