2019 Fiscal Year Final Research Report

Integrated understanding of plastic alteration of vestibular system and countermeasures for adaptive disorder

Planned Research

PDF

Project Area	"LIVING IN SPACE" - Integral Understanding of life-regulation mechanism from "SPACE"
Project/Area Number	15H05940
Research Category	Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)
Allocation Type	Single-year Grants
Review Section	Complex systems
Research Institution	Gifu University
Principal Investigator	Morita Hironobu 岐阜大学, 大学院医学系研究科, 教授 (80145044)
Co-Investigator(Kenkyū-buntansha)	梶博史近畿大学, 医学部, 教授 (90346255) 上田陽一産業医科大学, 医学部, 教授 (10232745) 岩崎真一東京大学, 医学部附属病院, 准教授 (10359606) 村谷匡史筑波大学, 医学医療系, 教授 (50730199)
Project Period (FY)	2015-06-29 – 2020-03-31
Keywords	耳石前庭系 / 可塑的変化 / 筋－骨連関 / 球形嚢 / 前庭神経核 / 前庭電気刺激 / 平衡機能障害 / 起立性低血圧
Outline of Final Research Achievements	Under the hypothesis that plastic changes in the otolith vestibular system, which is a sensing organ of gravity, are involved in the causes of various medical problems associated with microgravity, we investigated the changes in otolith sensory cells and vestibular nuclei, which are primary neurons, caused by the microgravity environment, and obtained the following results. In addition to previously known functions, the vestibular system is involved in various body function regulation such as feeding, glucose metabolism, body temperature, blood pressure, regulation of muscle mass/bone mass. These functions change when exposed to different gravitational environments with strong plasticity. This plastic change involves changes in gene expression in the saccule and vestibular nuclei. It was suggested that the method of electrically stimulating the vestibular system might be useful as a countermeasure against plastic changes.
Free Research Field	生理学，環境生理学，宇宙医学
Academic Significance and Societal Importance of the Research Achievements	「宇宙は老化のアクセラレータである」と言われるように，宇宙飛行に伴う医学的問題―平衡機能障害，起立性低血圧，筋量・骨量減少―は高齢者にもみられる症状であり，高齢者において活動量減少に伴う前庭への入力減少により，前庭機能が低下して，これらの症状を引き起こしている可能性がある。実際，高齢者では，前庭－血圧反射の調節力が大きく損なわれており，それが起立性低血圧の原因となっている。本研究成果は，重力変化に対する生体適応を理解し，それによって引き起こされる医学的問題の発症機序解明に貢献し，宇宙飛行士の健康増進法を提案したのみならず，この方法を高齢者に適応し，QOL改善につなげる可能性が示唆された。