Acta Medica Okayama 0065-1583 59 1 2020 Immunocytochemical Analysis of α-Tubulin Distribution Before and After Rapid Axopodial Contraction in the Centrohelid Raphidocystis contractilis 1 12 EN Risa Ikeda Laboratory of Cell Physiology, Department of Science Education, Graduate School of Education, Okayama University Miki Kurokawa Laboratory of Cell Physiology, Department of Science Education, Graduate School of Education, Okayama University Momoka Murai Laboratory of Cell Physiology, Department of Science Education, Graduate School of Education, Okayama University Noboru Saito Laboratory of Animal Physiology and Pharmacology, Department of Animal Science, Graduate School of Environmental and Life Science, Okayama University Motonori Ando Laboratory of Cell Physiology, Department of Science Education, Graduate School of Education, Okayama University The centrohelid Raphidocystis contractilis is a heliozoan that has many radiating axopodia, each containing a bundle of microtubules. Although the rapid contraction of the axopodia at nearly a video rate (30 frames/s) is induced by mechanical stimuli, the mechanism underlying this phenomenon in R. contractilis has not yet been elucidated. In the present study, we described for the first time an adequate immunocytochemical fixation procedure for R. contractilis and the cellular distribution of α-tubulin before and after rapid axopodial contraction. We developed a flow-through chamber equipped with a micro-syringe pump that allowed the test solution to be injected at a flow rate below the threshold required to induce rapid axopodial contraction. Next, we used this injection method for evaluating the effects of different combinations of two fixatives (paraformaldehyde or glutaraldehyde) and two buffers (phosphate buffer or PHEM) on the morphological structure of the axopodia. A low concentration of glutaraldehyde in PHEM was identified as an adequate fixative for immunocytochemistry. The distribution of α-tubulin before and after rapid axopodial contraction was examined using immunocytochemistry and confocal laser scanning fluorescence microscopy. Positive signals were initially detected along the extended axopodia from the tips to the bases and were distributed in a non-uniform manner within the axopodia. Conversely, after the induction of a rapid axopodial contraction, these positive signals accumulated in the peripheral region of the cell. These results indicated that axopodial microtubules disassemble into fragments and/ or tubulin subunits during rapid axopodial contraction. Therefore, we hypothesize that the mechanism of extremely rapid axopodial contraction accompanied by cytoskeletal microtubule degradation in R. contractilis involves microtubule-severing at multiple sites. No potential conflict of interest relevant to this article was reported.

岡山実験動物研究会 Acta Medica Okayama 34 2018 無腸動物Praesagittifera naikaiensis における細胞骨格要素 21 27 EN Risa Ikeda Graduate School of Education, Okayama University Chiho Fujiwara Graduate School of Education, Okayama University Mayuko Hamada Ushimado Marine Institute, Faculty of Science, Okayama University Tatsuya Sakamoto Ushimado Marine Institute, Faculty of Science, Okayama University Noboru Saito Graduate School of Environmental and Life Science, Okayama University Motonori Ando Graduate School of Education, Okayama University Acoel flatworms can move in a variety of ways such as muscular and ciliary movements via cytoskeletal elements and their neural regulations. However, those locomotive mechanisms have not yet been fully elucidated. In this study, we examined the distribution of cytoskeletal elements including filamentous actin (F-actin) and tubulin, and the neuroanatomical organization in an acoelomorph worm, Praesagittifera naikaiensis (P. naikaiensis). Video microscopy revealed the elongation/contraction and the bending/rotation processes, and the ciliary gliding movement of P. naikaiensis. Histochemical and morphological analysis demonstrated that F-actin networks of inner longitudinal and outer circular muscle fibers were positioned along the entire surface of the body, and that the average distance between the circular muscle fibers in the contracted organism was decreased in the anterior region compared with that in the elongated organism. Electron microscopy showed dense bodies on the muscle cells of P. naikaiensis, which indicates that those muscle cells have the appearance of vertebrate smooth muscle cells. Immunohistochemical analysis revealed that -tubulin-positive signals on the ciliary microtubules had close contact with the F-actin network, and that neurite bundles labelled with anti dSap47 antibody as a neuronal marker run along the anterior-posterior body axis. These results indicate that the well-organized cytoskeletal elements and their neural control systems are preserved in P. naikaiensis, and that their mechanisms involved in those regulation systems are similar to those vertebrate systems. Further studies are needed to clarify the physiological mechanisms underlying the muscular and ciliary movements in P. naikaiensis. No potential conflict of interest relevant to this article was reported.

岡山実験動物研究会 Acta Medica Okayama 33 2017 鳥類内耳tegmentum vasculosum の構造と機能 26 30 EN Risa Ikeda Laboratory of Cell Physiology, Department of Science Education, Graduate School of Education, Okayama University Tsuyoshi Otono Laboratory of Cell Physiology, Department of Science Education, Graduate School of Education, Okayama University Naoya Ikeda Laboratory of Cell Physiology, Department of Science Education, Graduate School of Education, Okayama University Noboru Saito Laboratory of Animal Physiology and Pharmacology, Department of Animal Science, Graduate School of Environmental and Life Science, Okayama University Motonori Ando Laboratory of Cell Physiology, Department of Science Education, Graduate School of Education, Okayama University In spite of the importance of endocochlear DC potential (EP) and the K+-rich endolymph for the avian cochlea, the structure and function of the tegmentum vasculosum (TV) has not yet been fully elucidated, compared with those of the stria vascularis in the mammalian cochlea. In this study, we examined structural analysis of the epithelial cells, gene expressions of Na+-K+-ATPase (Atp1A1) and Kir4.1 (Kcnj10), and protein localizations of Na+-K+-ATPase and Kir4.1, in the TV. Tight junctional structures were observed between epithelial dark cells and light cells in the TV. Both Atp1a1 and Kcnj10 genes were detected in the TV. In addition, immunopositive signals for both Na+-K+-ATPase and Kir4.1 were recognized in the TV. These results indicate that Na+-K+-ATPase and Kir4.1 play roles in maintaining the EP and high K+ concentration of the endolymph. Further studies are needed to clarify the physiological functions of the TV. This is the first report which demonstrates that gene and protein expression data contribute to the avian inner ear homeostasis. No potential conflict of interest relevant to this article was reported.

岡山実験動物研究会 Acta Medica Okayama 31 2015 蝸牛管側壁におけるミオイノシトール輸送体タンパク質の発現 55 58 EN Mayumi Yamaji Risa Inoue Midori Edamatsu Motonori Ando No potential conflict of interest relevant to this article was reported.

岡山大学教育学部附属教育実践総合センター Acta Medica Okayama 1346-3705 9 1 2009 理科教材･授業案開発を指向した新しい学部講義の実践 97 102 EN Yoshihiko Inada Izumi Irie Kozo Atobe Motonori Ando Teruhiko Ishikawa Koji Uno Hisakazu Ogura Seiji Kakihara Kuranoshin Kato Masakazu Kita Kenji Tanaka 10.18926/15108 岡山大学教育学部の理科教育講座に所属する3年生を対象に,理科教材･授業案開発を指向した新しい講義を始めたのでその報告を行う｡本講義では,近隣の小,中学校や公民館,科学館等の協力も得て実践の場を確保し,開発した教材や授業案を実践することで生きた教材開発の訓練を行なうことを目指している｡教科内容学担当教員と教科教育学担当教員の協働を模索すると同時に,大学教員の教科内容の専門知識や技量を教材や授業案に有効に活用できる講義を意識した。 No potential conflict of interest relevant to this article was reported.

岡山大学教育学部附属教育実践総合センター Acta Medica Okayama 1346-3705 7 1 2007 岡山大学大学院理科教育専攻で行った教材・授業案開発講義の試み 1 7 EN Yoshihiko Inada Seiji Kakihara Masakazu Kita Nobuhiko Yamashita Teruhiko Ishikawa Hisakazu Ogura Motonori Ando Isao Kusachi Kuranoshin Kato Tsutomu Yoshioka Yuki Kawata Motoshi Hirakawa Seiji Hashimoto Tetsuya Akazaki Nobuhiko Higashi Akio Becchaku 10.18926/14367 岡山大学大学院教育学研究科の理科教育専攻の講義として、教材開発・授業案開発をテーマとした新しい講義を試みたのでその報告を行う。本講義は、理科教育講座に所属する大学院生、理科教育講座の大学教員、附属学校の理科関係の教諭が三者協働で進めることが特徴である。課題設定、教材開発を含めた実践準備および実践を院生チームを組み遂行させ、さらに経験や専門性の異なる人材と論議を重ねて活動を進めることを通じ、将来、協働で学校現場の課題提案・解決を行うことのできる能力を養うことを目標とした。 No potential conflict of interest relevant to this article was reported.