Establishment of the chrono-health science by understanding irregular life style

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K11606
• 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: Hiroshima University (2022-2023); Waseda University (2021)
• Principal Investigator: Tahara Yu 広島大学, 医系科学研究科(医), 准教授 (80707399)
• Co-Investigator(Kenkyū-buntansha): 高松 敦子 早稲田大学, 理工学術院, 教授 (20322670)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 概日時計

Outline of Final Research Achievements

We created the irregular lifestyle model mice by slightly changing the light-dark cycle daily, and by dividing the periodicity into 3, 7, and 14 days, we established a system to systematically analyze irregularity. Regarding behavioral rhythms, it was confirmed that it is difficult for the mice to keep up with the irregular changes of the 3-day cycle, while they can keep up with the 14-day cycle. We analyzed the body temperature of mice kept under various light conditions and successfully quantified the state of jet lag between the central clock (behavioral rhythm) and the peripheral clock (deep body temperature rhythm) due to changes in the light-dark cycle. As a result, it was found that changing the light-dark cycle every three days causes the greatest jet lag within the body.

Free Research Field

時間生物学

Academic Significance and Societal Importance of the Research Achievements

概日時計を健康に保つことは、予防医学として重要であり、また健康寿命延伸にも繋がる。概日時計は24時間ピッタリではなく、環境因子（光、食事、運動）により時刻調節を日々行う。しかし、普段の生活では朝昼夕と食事を摂り、通勤・通学を運動と捉えれば朝、夕２回の活動ピークが来るゆらぎを持った入力となる。これら実生活における環境入力は複雑であり、いかに相互作用し、概日時計の時刻を調節し、時に時差ボケを引き起こすのかは、まだよく分かっていない。本研究結果は、普段起こり得る不規則さに焦点をあてた新規課題であり、時差ボケを数値化できる可能性を示したことは社会的にみても有用である。