The process of target recognition within motor columns revealed by in vivo analysis of the behavior of collateral branches arising from the post-crossing segment of dI1-class commissural axons
| Project/Area Number |
16K07028
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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 |
Nerve anatomy/Neuropathology
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| Research Institution | Osaka University |
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Principal Investigator |
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| Research Collaborator |
KANEYAMA takeshi
OTOBE ryosuke
ONO katsuhiko
TAKEBAYASHI hirohide
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| Project Period (FY) |
2016-04-01 – 2019-03-31
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| Project Status |
Completed (Fiscal Year 2018)
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| Budget Amount *help |
¥5,070,000 (Direct Cost: ¥3,900,000、Indirect Cost: ¥1,170,000)
Fiscal Year 2018: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
Fiscal Year 2017: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
Fiscal Year 2016: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
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| Keywords | 神経回路形成 / 軸索ガイダンス / 標的認識 / 交連ニューロン / 運動ニューロン / 軸索側枝 / 脊髄 / マウス / 子宮内電気穿孔法 / 運動ニューロン欠損マウス / 神経回路網形成 / 神経細胞クラス特異的遺伝子発現系 / 樹状突起発達 / 神経科学 / 発生・分化 |
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| Outline of Final Research Achievements |
We examined the behavior of post-crossing dI1-class commissural axons in mice, using the Atoh1 enhancer-based conditional gene expression system that enables selective and sparse labeling of individual dI1 axons in vivo. For precise identification of spinal motor neurons (MNs), we combined this approach with Hb9 and ChAT immunohistochemistry, together with MN-selective genetic labeling. We found that dI1 commissural neurons developed axonal projection to spinal MNs via collateral branches arising later from the post-crossing segment of these axons. We also found that these collateral branches further gave rise to multiple secondary branches in the region of MNs that specifically innervate axial muscles. Moreover, these axonal branches formed presynaptic terminals on the proximal portion of the MN dendrites. Our findings thus reveal a previously unrecognized projection of dI1 commissural axons that contribute to the ventral spinocerebellar tract in the mammalian central nervous system.
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| Academic Significance and Societal Importance of the Research Achievements |
これまでの研究から、脊髄dI1型交連ニューロンの軸索は解剖学的に脊髄小脳路を構成し小脳虫部に投射していることが知られていたが、脊髄運動ニューロンとの関わりは不明であった。本研究により、脊髄の体幹筋を支配する運動ニューロンもdI1型交連ニューロン軸索の標的細胞であることが示され、dI1型交連ニューロンが小脳虫部と体幹筋を支配する運動ニューロンを回路として結びつける役割を担っていることが明らかとなった。一方で脊髄小脳変性症においては、脊髄小脳路系にも病変が認められる型があることから、本研究の結果はdI1型交連ニューロンの障害でも脊髄小脳変性症に特徴的な運動失調が引き起こされる可能性を示唆する。
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Report
(4 results)
Research Products
(5 results)
