Structural and functional changes in the brain due to fatigue, aging, and their interaction

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K11708
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 59040:Nutrition science and health science-related
• Research Institution: Institute of Physical and Chemical Research
• Principal Investigator: Sasaki Akihiro 国立研究開発法人理化学研究所, 生命機能科学研究センター, 研究員 (10711781)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: 加齢 / 疲労 / 脳 / MRI

Outline of Final Research Achievements

In this study, we investigated the multiple variables of cortical microstructures (CM) including myelin and neurite in association with subject measures (SM) including age, fatigue, and cognitive function in a cross-sectional MRI study. The cortical surface-based analysis was performed for estimating cortical thickness, myelin contrast and neurite density as well as extra neurite compartment. Canonical correlation analysis (CCA) using multi-modal brain metrics and subject measures revealed that CCA1 for SM is highly correlated with age and the cognitive performances relevant to set-shifting, while not significantly correlated with affective states and fatigue index. The loading of CCA1 for CM is correlated with myelin and NDI and inversely correlated with ExNDI and cortical thickness. This finding suggests that the brain transitions from a plastic to a stable system throughout the lifespan, which may support the crystallization of cognition.

Free Research Field

健康科学

Academic Significance and Societal Importance of the Research Achievements

世界中で高齢化が加速している。中でも日本は2019年に世界に先駆け超高齢化時代を迎えている。これまでの研究から加齢はしばしば認知機能の低下や脳の萎縮と関連を示めされきている。しかしながら、大脳皮質を構築するミエリンや神経突起さらにはグリアなどの微細構造がヒトのライフスパンにおいてどのように変化するかはほとんど分かっていなかった。本研究では若年から老年までの横断的な脳画像データを用いて、皮質微細構造の加齢変化を明らかにすることで、ヒトの脳がライフスパンを通して可塑的なシステムから安定的なシステムへと移行する可能性を示した。