Mechanisms in motro recovery aftre spina cord injury by electrical stimulation induced muscle contraction

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K10804
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 59010:Rehabilitation science-related
• Research Institution: Kawasaki Medical School
• Principal Investigator: MIYAMOTO OSAMU 川崎医科大学, 医学部, 教授 (00253287)
• Co-Investigator(Kenkyū-buntansha): 丸山 恵美 川崎医科大学, 医学部, 助教 (30792072) ; 氷見 直之 川崎医科大学, 医学部, 講師 (70412161)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: 脊髄損傷 / 骨格筋収縮 / 電気刺激 / 皮質脊髄路 / 軸索再生 / BDNF / TrkB / ANA-12

Outline of Final Research Achievements

The involvement of neurotrophic factors such as brain-derived neurotrophic factor (BDNF) in functional recovery after spinal cord injury (SCI) by treadmill training has been suggested. However, the precise mechanism is poorly understood. To investigate the role of muscle contraction in motor function recovery after SCI, with a focus on BDNF. Percutaneous electrical muscle stimulation (ES) was applied to both hindlimbs of the SCI model rats. Motor function was assessed using BBB score, inclined plane test, and rotarod test. Significant improved motor function, axonal regeneration of corticospinal tract, and BDNF production in both muscle and spinal cord were observed by ES. While, these effects were suppressed by administration of the TrkB blocker. These results indicate that the increase of muscle activity induces motor recovery after SCI via BDNF-TrkB pathway.

Free Research Field

神経病理学

Academic Significance and Societal Importance of the Research Achievements

現在、脊損患者に対しては運動療法を中心とするリハビリが行われているが中枢神経の再生能力は極めて低く、脊損患者の大部分に四肢麻痺や感覚障害などの永続的な後遺症が残る。一方、脊損後の運動が脊髄の再生を誘導し、これが運動機能の回復に寄与するという報告がなされているがそのメカニズムは明らかではない。本研究では、「脊損患者に対する運動リハビリ時の筋活動が逆行性に脊髄にシグナルを伝えて損傷部位の軸索再生や細胞新生を促進する」という仮説を立てこれを検証し、その分子メカニズムの一端を明らかにした。本研究結果により、BDNF-TrkB経路の活性化をターゲットとした新たな治療法の開発が大いに期待される。