Possible central mechanism of acquired heat tolerance in exercise-trained rats

2022 Fiscal Year Final Research Report

• Project/Area Number: 18K06853
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 48020:Physiology-related
• Research Institution: Shimane University
• Principal Investigator: Matsuzaki Kentaro 島根大学, 学術研究院医学・看護学系, 講師 (90457185)
• Co-Investigator(Kenkyū-buntansha): 紫藤 治 島根大学, 学術研究院医学・看護学系, 教授 (40175386) ; 片倉 賢紀 城西大学, 薬学部, 准教授 (40383179) ; 住吉 愛里 島根大学, 学術研究院医学・看護学系, 助教 (40782404)
• Project Period (FY): 2018-04-01 – 2023-03-31
• Keywords: 暑熱馴化 / 体温調節 / 視床下部

Outline of Final Research Achievements

The aim of the present study was to investigate whether exercise training induces hypothalamic neurogenesis in rats. Male, 6-week-old Wistar rats were initially maintained at an ambient temperature of 24 °C for 10 days. They were then kept for 30-40 days in cages either with a running wheel (exercise rats, EX) or with a locked wheel (control rats, CN). The numbers of BrdU-immuno-positive (BrdU+) cells in the hypothalamus of EX were significantly greater than that of CN. Moreover, the number of hypothalamic BrdU+ cells double-stained with neuronal differentiation marker, doublecortin, of EX were significantly higher than that of CN. These results suggest that exercise training facilitates proliferation of neuronal progenitor cells and promotes differentiation into neurons in the hypothalamus, which might have a certain role in acquired heat tolerance of exercise-trained rats.

Free Research Field

生理学

Academic Significance and Societal Importance of the Research Achievements

夏季の熱中症が深刻な社会問題になっている。持続的な暑熱曝露や運動トレーニングにより形成される暑熱馴化は熱中症の予防法として有望視されているが、その中枢機序は不明であった。これまでに私たちは、暑熱曝露されたラットでは体温調節中枢が存在する視床下部において神経新生が促進され、新生したニューロンが暑熱馴化の形成に関与することを世界で初めて明らかにした。暑熱馴化形成の中枢機序として、視床下部神経の可塑的変化が関わることを証明した本研究には学術的意義があると思われる。