Development of an animal model to elucidate the pathophysiology of postoperative REM sleep rebound

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K23078
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0907:Oral science and related fields
• Research Institution: Osaka University
• Principal Investigator: Ueno Yoshio 大阪大学, 大学院歯学研究科, 招へい教員 (50880118)
• Project Period (FY): 2020-09-11 – 2023-03-31
• Keywords: 術後レム睡眠リバウンド / 周術期管理 / 術後せん妄

Outline of Final Research Achievements

To analyze physiological changes in the process of postoperative REM sleep rebound, we performed sleep recording for 70 hours after oral surgery (partial tongue resection) under isoflurane anesthesia in rats (Iso-Ope group). The data were compared with those of animals with no intervention (naive group) and with isoflurane anesthesia (Iso group). In Iso-Ope group, time in REM sleep was lower during dark period after surgery compared to other two groups and, during the following light period, time in REM sleep did not increase remarkably. Theta EEG activity did not decrease during dark period in ISO-Ope group. Although sleep-wake cycles were preserved after surgery, the amount of wake period was higher for recording periods in Iso-Ope group than naive and Iso groups. These results suggest that the present experimental conditions can be used for the future studies on REM sleep rebound and sleep disturbance after oral surgery.

Free Research Field

口腔顎顔面外科学

Academic Significance and Societal Importance of the Research Achievements

口腔外科臨床では、術後せん妄は術後2、3日の意識清明期を経て発症する。術後レム睡眠リバウンドは、上気道拡大筋の著明な弛緩により、気道閉塞による反復型低酸素血症を引き起こし、術後せん妄を発症させる可能性がある。しかし、術後のレム睡眠リバウンドなどの口腔外科手術の周術期に発生する現象は、安全面からも倫理的な側面からも患者において生理学的事象を測定することは困難である。本研究成果により全身麻酔下の口腔外科手術後の影響を実験動物で測定することにより、麻酔薬や手術内容による術後睡眠の発生原因の解明や、その対応や診断方法を開発するうえで有用な実験系の１つとなりうる点で学術的な意義があると考える。