Brain mechanisms of central fatigue during endurance exercise: A role of brain glycogen-derived lactate

2022 Fiscal Year Final Research Report

• Project/Area Number: 19H03994
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 59020:Sports sciences-related
• Research Institution: University of Tsukuba
• Principal Investigator: Matsui Takashi 筑波大学, 体育系, 助教 (80725549)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: 運動 / 疲労 / 脳 / 乳酸 / グリコーゲン

Outline of Final Research Achievements

Fatigue during exercise can be categorized into peripheral and central types, and although each is being extensively researched, the underlying integrated mechanisms and the fundamental significance of fatigue remain elusive. In this study, we utilized an animal model of fatiguing exercise and conducted cutting-edge neurobiological experiments involving the activation of lactate receptors. We demonstrated for the first time that lactate derived from brain glycogen not only serves as an energy source in the brain during exercise, but also acts as an inhibitory signal, potentially contributing to the formation of central fatigue. These findings lend support to the dual view of fatigue as not only an undesirable condition to overcome, but also as a biological defense mechanism preventing overexertion.

Free Research Field

スポーツ神経生物学

Academic Significance and Societal Importance of the Research Achievements

疲労はアスリートはもちろん、多くの人々の日常生活でも生じ、克服したい憎い存在と考えられがちである。しかし、裏を返せば、疲労はオーバートレーニングや過活動を未然に防いでくれるアラートとして働くとも理解できる。本研究では、疲労運動の動物モデルにおける神経シグナル操作により、疲労を生み出す脳機構の一部に乳酸が関与し、脳のエネルギーとなることで脳を保護しながら、神経の抑制信号として心身の活動を抑える可能性を明らかにした。この成果は、上述の二面性がどちらも疲労の本質であるという前提を支持し、健全な疲労の予防・克服方策開発の道を開くものである。