| Project/Area Number |
16K07003
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Research Field |
Neurophysiology / General neuroscience
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| Research Institution | Showa University |
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Principal Investigator |
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| Project Period (FY) |
2016-04-01 – 2020-03-31
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| Project Status |
Completed (Fiscal Year 2019)
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| Budget Amount *help |
¥4,030,000 (Direct Cost: ¥3,100,000、Indirect Cost: ¥930,000)
Fiscal Year 2018: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2017: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2016: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
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| Keywords | Phox2b / 呼吸リズム / トランスジェニックラット / オプトジェネティクス / チャネルロドプシン / アーチロドプシン / 吻側腹外側延髄 / 新生児ラット / 脳幹‐脊髄標本 / アーキロドプシン / 神経科学 / 新生児 / ラット |
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| Outline of Final Research Achievements |
We developed a transgenic (Tg) rat line in which Phox2b-positive cells expressed archaerhodopsin-3 (Arch) or the step-function channelrhodopsin variants (ChRFR) under the control of Phox2b promoter-enhancer regions. We analyzed a local neuron network of the respiratory center in the medulla of a brainstem-spinal cord preparation isolated from 0-2-day-old Tg rat. The photostimulation induced inhibition or facilitation of the respiratory rhythm in Arch-expressing or ChRFR-expressing Tg rats, respectively. Phox2b-positive Pre-I neurons were hyperpolarized or depolarized in Arch-expressing or ChRFR-expressing Tg rat preparations, respectively. The photostimulation induced heterogeneous membrane potential changes of other respiratory-related neurons, depending on properties of synaptic connections (especially between Pre-I neurons) in the respiratory center. The optogenetic approach was a powerful method of verifying a hypothetical model of local networks among respiratory-related neurons.
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| Academic Significance and Societal Importance of the Research Achievements |
本研究では，非スライスin vitro 脳標本である新生児ラット脳幹―脊髄標本を用いた．これはオプトジェネティクスによる呼吸中枢神経回路の解析としては世界で初めての試みとなった．摘出脳幹標本は，Cre-loxP システムを用いた遺伝子組み換えによって，Phox2b 遺伝子の発現制御領域下に光感受性チャネル（アーキロドプシンおよびチャネルロドプシン）を発現させた新生児ラット（生後０－２日）から摘出した．光感受性チャネルを選択的に光刺激することによって引き起こされる呼吸リズムの変化，呼吸性ニューロンの膜電位変化などを詳細に解析することで，呼吸中枢の神経回路の動作特性が明瞭に示すことができた．
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