Data base of TRP channels involving triggering of swallowing reflex and prevention of aspiration

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K05871
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 38050:Food sciences-related
• Research Institution: Matsumoto Dental University
• Principal Investigator: Ando Hiroshi 松本歯科大学, 歯学部, 准教授 (30312094)
• Co-Investigator(Kenkyū-buntansha): Hossain M.Zakir 松本歯科大学, 歯学部, 助教 (40792445) ; 北川 純一 松本歯科大学, 歯学部, 教授 (50373006) ; 海野 俊平 松本歯科大学, 歯学部, 講師 (80418920)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 嚥下 / TRPチャネル / 喉頭 / 咽頭 / 上喉頭神経 / TRPA1

Outline of Final Research Achievements

TRPA1s were predominantly expressed on thin nerve fibres and fibroblast-like cells in the SLN-innervated regions and on small to medium-sized SLN-afferents in the NPJc. Topical application of a chemical agonist for TRPA1, allyl isothiocyanate (AITC), in the regions triggered swallowing reflexes which were significantly attenuated by prior application of a TRPA1 antagonist. The topical application of cold AITC (4°C) very briefly reduced the on-site temperature to <17°C (temperature at which TRPA1s can be activated) but failed to augment the AITC-induced reflexes. TRPA1s function as chemosensors, but not as cold sensors or mechanosensors, to trigger the swallowing reflex. Brief application of a cold stimulus in the regions exerts no effect on triggering the reflex because of the rapid recovery of on-site temperature. Conversely, prolonged application of a cold stimulus delays/prevents triggering of the reflex because of the development of cold anaesthesia.

Free Research Field

機能系歯科学

Academic Significance and Societal Importance of the Research Achievements

飲食物を飲み込む時の咽頭・喉頭領域の感覚は上喉頭神経に受容される。この神経においてTRPA1チャネルが発現することを明らかにした。さらに、TRPA1の作動薬が嚥下を誘発することを明らかにした。これらの結果から咽頭・喉頭領域における感覚形成および嚥下誘発の神経機構の一端を明らかにすることができた。この成果は、高齢化社会を迎えた日本が抱えている社会問題でもある嚥下障害を解決するための、摂食嚥下リハビリテーションや嚥下食開発に貢献できる。