Elucidation of the mechanism of sleepiness/arousal level control by the parabrachial nucleus: a basic study for improving rehabilitation efficiency

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K11367
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 59010:Rehabilitation science-related
• Research Institution: Shimane University
• Principal Investigator: Shigefumi Yokota 島根大学, 学術研究院医学・看護学系, 准教授 (50294369)
• Co-Investigator(Kenkyū-buntansha): 武田 湖太郎 藤田医科大学, 保健学研究科, 准教授 (50618733) ; 濱 徳行 島根大学, 学術研究院医学・看護学系, 助教 (60422010)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: 低酸素 / 孤束核 / 結合腕傍核 / 覚醒中枢 / 呼吸中枢

Outline of Final Research Achievements

In this study, morphological investigations were conducted to determine the neural pathways that transmit blood chemical information to the arousal center (hypothalamic perifornical region) and the respiratory center (ventrolateral medulla). In the solitary nucleus, where peripheral chemical information is input, many glutamatergic neurons responded to intermittent hypoxic exposure. Analysis of neural pathways using genetically modified animals revealed that glutamatergic neurons in the solitary nucleus projected to the hypothalamic perifornical region or medullary respiratory center via the parabrachial nucleus. Furthermore, neurons constituting these neural pathways were found to be activated by intermittent hypoxic exposure. These neural pathways may be involved in the arousal and respiratory arousal induced by obstructive sleep apnea.

Free Research Field

神経解剖学

Academic Significance and Societal Importance of the Research Achievements

本研究では血中低酸素情報を覚醒中枢および呼吸中枢へ至る神経路を明らかにした。睡眠時無呼吸のような睡眠障害が引き起こす日中の眠気や認知機能の低下は転倒リスクを増大させるのみならず、リハビリテーション訓練への意欲を低下させ、また、集中力を欠如させるため訓練効果が低下するなど重大な負の影響が報告されている。したがって、血中酸素分圧の低下が覚醒および呼吸の増大を惹起する神経路を明らかにすることは、睡眠時無呼吸症の発症メカニズムを解明し、臨床的な治療へつながる基礎的な知見を与えるものである。