Shinotsuka, Takanori



School of Medicine, Department of Pharmacology (Shinanomachi)



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Career 【 Display / hide

  • 2014.04

    Japan Society for the Promotion of Science, 特別研究員

  • 2016.04

    The University of Tokyo, Graduate School of Medicine, 特任研究員

  • 2018.04

    Japan Society for the Promotion of Science, 特別研究員

  • 2021.04

    The University of Tokyo, Graduate School of Medicine, 特任研究員

  • 2021.09

    Keio University, School of Medicine, 助教

Academic Background 【 Display / hide

  • 2005.04

    Tokyo University of Science, Faculty of Pharmaceutical Sciences

  • 2009.04

    Tokyo University of Science, Graduate School of Pharmaceutical Sciences

  • 2011.04

    Keio University, 医学系研究科


Research Areas 【 Display / hide

  • Life Science / Neuroscience-general

  • Life Science / Pharmacology

Research Keywords 【 Display / hide

  • Multiphoton imaging


Papers 【 Display / hide

  • Norepinephrine induces rapid and long-lasting phosphorylation and redistribution of connexin 43 in cortical astrocytes

    Mutsuo Nuriya, Ayaka Morita, Takanori Shinotsuka, Tomoko Yamada, Masato Yasui


    Research paper (scientific journal), Joint Work, Accepted,  ISSN  0006291X

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    Norepinephrine (NE) modulates brain functions depending on both the internal and external environment. While the neuromodulatory actions of NE have been well characterized, the response and involvement of cortical astrocytes to physiological noradrenergic systems remain largely unknown, especially at the molecular level. In this study, we biochemically characterize the action of NE on astrocytes of the murine neocortex. NE stimulation of acute brain slices rapidly increase phosphorylation of connexin 43 (Cx43) at Serine (Ser) 368, in slices from both juvenile and adolescent animals. The phosphorylation is mediated by the protein kinase C (PKC) pathway under the alpha 1-adrenergic receptor and remains elevated for tens of minutes following brief exposure to NE, well after the intracellular calcium level returns to normal level, suggesting the plastic nature of this phosphorylation event. Importantly, this phosphorylation event persists in the absence of neuronal transmissions, suggesting that the effect of NE on Cx43 phosphorylation is induced directly on astrocytes. Furthermore, these NE-induced phosphorylations are associated with biochemical dissociation of Cx43 from gap-junctional plaques to non-junctional compartments. Finally, we show that pharmacological manipulation of the noradrenergic system using psychoactive drugs modulates phosphorylation of Cx43 in the cerebral cortex in vivo. These data suggest that NE acts directly on astrocytes in parallel with neurons and modulates functionally critical connexin channel proteins in a plastic manner. Thus, plasticity of astrocytes induced by the "gliomodulatory" actions of NE may play important roles in their physiological as well as pharmacological actions in the brain. (C) 2018 Elsevier Inc. All rights reserved.

  • Multimodal two-photon imaging using a second harmonic generation-specific dye

    Mutsuo Nuriya, Shun Fukushima, Atsuya Momotake, Takanori Shinotsuka, Masato Yasui, Tatsuo Arai


    Research paper (scientific journal), Joint Work, Lead author, Accepted,  ISSN  2041-1723

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    Second harmonic generation (SHG) imaging can be used to visualize unique biological phenomena, but currently available dyes limit its application owing to the strong fluorescent signals that they generate together with SHG. Here we report the first non-fluorescent and membrane potential-sensitive SHG-active organic dye Ap3. Ap3 is photostable and generates SH signals at the plasma membrane with virtually no fluorescent signals, in sharp contrast to the previously used fluorescent dye FM4-64. When tested in neurons, Ap3-SHG shows linear membrane potential sensitivity and fast responses to action potentials, and also shows significantly reduced photodamage compared with FM4-64. The SHG-specific nature of Ap3 allows simultaneous and completely independent imaging of SHG signals and fluorescent signals from various reporter molecules, including markers of cellular organelles and intracellular calcium. Therefore, this SHG-specific dye enables true multimodal two-photon imaging in biological samples.

  • Sustained Down-regulation of beta-Dystroglycan and Associated Dysfunctions of Astrocytic Endfeet in Epileptic Cerebral Cortex

    Asako Gondo, Takanori Shinotsuka, Ayaka Morita, Yoichiro Abe, Masato Yasui, Mutsuo Nuriya


    Research paper (scientific journal), Joint Work, Lead author, Accepted,  ISSN  0021-9258

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    Epilepsy is characterized by the abnormal activation of neurons in the cerebral cortex, but the molecular and cellular mechanisms contributing to the development of recurrent seizures are largely unknown. Recently, the critical involvement of astrocytes in the pathophysiology of epilepsy has been proposed. However, the nature of plastic modulations of astrocytic proteins in the epileptic cortex remains poorly understood. In this study, we utilized the zero magnesium in vitro model of epilepsy and examined the potential molecular changes of cortical astrocytes, focusing specifically on endfeet, where specialized biochemical compartments exist. We find that the continuous epileptic activation of neurons for 1 h decreases the expression level of beta-dystroglycan (beta DG) in acute cortical brain slices prepared from mice. This change is completely abolished by the pharmacological blockade of NMDA-type glutamate receptors as well as by matrix metalloproteinase inhibitors. Consistent with the highly specialized localization of beta DG at astrocytic endfeet, where it plays a pivotal role in anchoring endfeet-enriched proteins in astrocytes, the down-regulation of beta DG is accompanied by a decrease in the expression of AQP4 but not laminin. Importantly, this down-regulation of beta DG persists for at least 1 h, even after the apparent recovery of neuronal activation. Finally, we show that the down-regulation of beta DG is associated with the dysfunction of the endfeet at the blood-brain interface as a diffusion barrier. These results suggest that the sustained down-regulation of beta DG leads to dysfunctions of astrocytic endfeet in the epileptic cerebral cortex and may contribute to the pathogenesis of epilepsy.

  • Astrocytic gap junctional networks suppress cellular damage in an in vitro model of ischemia

    Takanori Shinotsuka, Masato Yasui, Mutsuo Nuriya


    Research paper (scientific journal), Joint Work, Lead author, Accepted,  ISSN  0006-291X

     View Summary

    Astrocytes play pivotal roles in both the physiology and the pathophysiology of the brain. They communicate with each other via extracellular messengers as well as through gap junctions, which may exacerbate or protect against pathological processes in the brain. However, their roles during the acute phase of ischemia and the underlying cellular mechanisms remain largely unknown. To address this issue, we imaged changes in the intracellular calcium concentration ([Ca2+](i)) in astrocytes in mouse cortical slices under oxygen/glucose deprivation (OGD) condition using two-photon microscopy. Under OGD, astrocytes showed [Ca2+](i) oscillations followed by larger and sustained [Ca2+](i) increases. While the pharmacological blockades of astrocytic receptors for glutamate and ATP had no effect, the inhibitions of gap junctional intercellular coupling between astrocytes significantly advanced the onset of the sustained [Ca2+](i) increase after OGD exposure. Interestingly, the simultaneous recording of the neuronal membrane potential revealed that the onset of the sustained [Ca2+](i) increase in astrocytes was synchronized with the appearance of neuronal anoxic depolarization. Furthermore, the blockade of gap junctional coupling resulted in a concurrent faster appearance of neuronal depolarizations, which remain synchronized with the sustained [Ca2+](i) increase in astrocytes. These results indicate that astrocytes delay the appearance of the pathological responses of astrocytes and neurons through their gap junction-mediated intercellular network under OGD. Thus, astrocytic gap junctional networks provide protection against tissue damage during the acute phase of ischemia. (C) 2014 Elsevier Inc. All rights reserved.

  • Tunable plasma lipoprotein uptake/transport across the blood-brain barrier

    Kenichiro Suzuki, Denis Adiguezel, Takanori Shinotsuka, Rei Ishibashi, Izumi Eguchi, Hideaki Oshima, Retsu Taniguchi, Stefan Thalhammer, Ken Takeda


    Research paper (scientific journal), Joint Work, Lead author, Accepted,  ISSN  0927-7757

     View Summary

    Brain development and maintenance requires transportation of cerebral sustenance across the blood brain barrier. Disorders of this process can induce neurodegenerative diseases, which can affect numerous patients and incur significant treatment expenses. Recent scientific advances suggest that knowledge of this transportation will lead to the development of tailor-made theranostic strategies. Biotechnological tools such as biocompatible nanoparticles have promising potential in this context, however, information about their consequences in the brain is largely unknown. The present study demonstrates the application of specifically constructed cerebral sustenance nanoparticles in the form of tunable plasma lipoproteins to provide information about their pathways to the brain and delivery to glia cells. Individual cell analysis in brain sections enabled us to understand the accumulation of tunable plasma lipoproteins in the cerebral cortex, striatum, and cerebellum, which have been previously identified as the incident regions of Alzheimer's disease, Parkinson's disease, and spinocerebellar ataxia. The adjustability of the tunable plasma lipoproteins enables their use in theranostic applications against neurodegenerative diseases. (C) 2013 The Authors. Published by Elsevier B.V. All rights reserved.

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Reviews, Commentaries, etc. 【 Display / hide

  • Visualization of water dynamics in brain tissue using multiphoton multimodal imaging

    Shinotsuka Takanori, Miyazawa Tsuyoshi, Karasawa Keiko, Ozeki Yasuyuki, Yasui Masato, Nuriya Mutsuo

    Proceedings for Annual Meeting of The Japanese Pharmacological Society (Japanese Pharmacological Society)  96   2-B-O05-1 2022

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    The flow of cerebrospinal fluid is considered to be a critical factor in the clearance of wastes in the brain. The dynamics of fluid has been investigated by several experimental methods such as fluorescence microscopy and magnetic resonance imaging. However, because probes used for these imagings are much larger compared to water itself, the dynamics of the fluid have been poorly understood. Here, we applied a multimodal multiphoton imaging system to the living brain tissue. Combining stimulated Raman scattering and two-photon fluorescent imaging, the system enables us to visualize spatiotemporal dynamics of deuterated water and fluorescent dyes simultaneously at a cellular level. We demonstrate that deuterated water diffuses faster than fluorescent dyes in the brain tissue. Detailed analysis reveals deuterated water rapidly exchanges inside and outside of cells, whereas fluorescent dyes only diffuse through extracellular spaces. Furthermore, we find that the dynamics of deuterated water is robust to changes under physiological and pathophysiological conditions; there is little change in the spatiotemporal dynamics of deuterated water during development and ischemia whereas fluorescent dyes are severely affected. Thus, our new approach reveals unique properties of the dynamics of the fluid in the living brain tissue.

  • Astrocytic gap junctional networks suppress cellular damages in an in vitro model of ischemia

    Takanori Shinotsuka, Masato Yasui, Mutsuo Nuriya


    ISSN  1347-8613

  • てんかんモデル条件下におけるアストロサイトの足突起のバリア機能の変化

    篠塚崇徳, 権藤麻子, 権藤麻子, 森田彩加, 森田彩加, 阿部陽一郎, 安井正人, 塗谷睦生, 塗谷睦生

    日本薬理学会関東部会プログラム・要旨集 131st 2014

  • Astrocytic gap junctional networks reduce ischemic damages in vitro

    SHINOTSUKA Takanori, NURIYA Mutsuo, YASUI Masato

    日本神経化学会大会抄録集(Web) 56th 2013

  • りん脂質修飾ナノ粒子の制御とそのマウス脳内における特異的分布(Controlling and spacific brain distribution of phospholipids-modified nanoparticles)

    篠塚 崇徳, 杉戸 雄四郎, 横田 理, 鈴木 健一郎, 武田 健

    神経化学 ((一社)日本神経化学会)  49 ( 2-3 ) 602 - 602 2010.08

    ISSN  0037-3796

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Research Projects of Competitive Funds, etc. 【 Display / hide

  • 大脳皮質運動野の層構造依存的に符号化された運動記憶情報の長期安定性機構の解明


    日本学術振興会, 科学研究費助成事業 特別研究員奨励費, 特別研究員奨励費, No Setting

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    本研究では学習によって形成される習熟運動が特定の神経細胞の神経活動として長期に安定に符号化されているかを検証してきた。その結果、習熟運動が時間経過に対し安定であること、さらにそのときの大脳皮質一次運動野 5a層の神経活動が安定であることを示唆する結果を得た。今年度はこれまでに得られた知見に関連した新たな知見を得るべく検証を進めた。具体的には習熟運動の学習に関連する分子メカニズムに関する検証を行った。また、習熟運動と大脳皮質一次運動野 5a層の神経活動の関係を細胞選択的な抑制・破壊実験を用いて検証した。
    習熟運動と大脳皮質一次運動野 5a層の神経集団活動の関係性を検証するために細胞選択的な抑制・破壊実験を導入した。大脳皮質5a層特異的にCre遺伝子を発現するマウスの運動野前肢領域にアデノ随伴ウイルスによってCre依存的に特定のタンパク質を発現させることによって、光遺伝学による神経活動抑制またはジフテリアトキシンによる細胞死を誘発させる。これらの細胞選択的な抑制・破壊実験によって、大脳皮質一次運動野5a層の神経活動を特異的に抑制・破壊した場合に習熟運動がどのような影響を受けるかについて検証を進めている。
    今後これらの検証をさらに進め、大脳皮質一次運動野 5a層の神経集団活動と習熟運動の長期安定性についての知見を深めて研究成果を報告するための準備を進める。

  • グルタミン酸とノルアドレナリンの協調的作用によるグリア細胞の脳血管制御機構の解明


    日本学術振興会, 科学研究費助成事業 特別研究員奨励費, 特別研究員奨励費, No Setting

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    平成26年度としては、グルタミン酸とノルアドレナリンがアストロサイトの生理学的な変化に対して協調的に働くかどうかについて2光子顕微鏡イメージング法とマウス急性脳スライス法を用いたin vitroの実験系で検討を進めた。その結果、グルタミン酸とノルアドレナリンがアストロサイトの生理学的な変化に対し、アドレナリン受容体のサブタイプ依存的な協調作用を示すことが示唆された。一方、ここ数年で急性脳スライス法による実験は血流がないために脳血管の反応を十分に調べられない可能性が示唆され始めており、in vivoの実験系を導入することが急務であると考えられた。そこで、平成27年度としては実験手法として新たに覚醒動物を用いたin vivoの研究手法を導入することで更なる研究の発展を試みた。in vivo の研究手法を導入するに当たり運動学習中の大脳皮質一次運動野(M1)に着目し、マウス右前肢レバー引き学習試験中のM1での2光子顕微鏡イメージングと薬物の局所投与を組み合わせる実験系の開発に取り組んだ。薬物をM1に限定的に投与するために、M1にガイドカニューラを設置したマイクロポンプによる薬物投与を導入した。この時の脳血管の変化を2光子顕微鏡で観察するための開頭手術を行い、ガラスを設置した。カニューラから蛍光物質のAlexa 594をマイクロポンプによって投与した結果、ポンプから排出された蛍光物質の拡散が観察されたことから、M1に対する限定的な薬物処理を行いつつ脳血管の変化の変化をin vivoでリアルタイムに観察することができる可能性を示した。