Mechanisms of Circadian Variation of Nociception in Trigeminal Area

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K10099
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 57060:Surgical dentistry-related
• Research Institution: Kagoshima University
• Principal Investigator: Sugimura Mitsutaka 鹿児島大学, 医歯学域歯学系, 教授 (90244954)
• Co-Investigator(Kenkyū-buntansha): 大野 幸 鹿児島大学, 医歯学域鹿児島大学病院, 客員研究員 (00535693) ; 山形 和彰 鹿児島大学, 医歯学域鹿児島大学病院, 助教 (40784195) ; 山下 薫 鹿児島大学, 医歯学域歯学系, 講師 (50762613)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 三叉神経系 / 体内時計 / 痛覚日内変動 / TRPA1 / ホルマリンテスト / PER2::LUCマウス

Outline of Final Research Achievements

The purpose of this study is to provide basic knowledge to establish effective control methods regarding "pain" from a temporal biological perspective. Formalin was injected into the trigeminal region of mice, and the duration of pain-related behavior (PRB) and c-Fos positive cells were counted. The results suggested that pain in the trigeminal region was more intense at night than during the day. Next, we examined the expression of clock genes in the trigeminal ganglion. A clear circadian rhythm was observed in the trigeminal ganglion. This clear circadian rhythm suggests that the trigeminal ganglion is responsible for relaying and time-gating sensory inputs, including pain, through autonomous circadian oscillations. These results were summarized and reported in a paper.

Free Research Field

歯科麻酔学

Academic Significance and Societal Importance of the Research Achievements

我々の今回の研究で、マウスにおける三叉神経支配領域の疼痛には昼夜差があることがわかった。学術的意義として、痛みの基礎研究では、痛みの感じ方には日内変動があることを念頭に置き、実験遂行の時間を揃えるだけではなく、マウスの概日リズムを厳密に整えることの重要性が示された。また、社会的意義として、既存の痛みの治療法に時間の概念を取り入れることで、新薬の開発に頼らずとも、より効果的な鎮痛薬の投薬を可能とする根據の１つになることが考えられた。