Pain control induced of serotonergic neurons of the rostral ventromedial medulla in the chronic pain of oral facial region

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K10799
• 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: Osaka University of Human Sciences
• Principal Investigator: Sugiyo Shinichi 大阪人間科学大学, 保健医療学部, 教授 (90397688)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: 神経障害性疼痛 / 下行性疼痛調節系 / 口腔顔面領域

Outline of Final Research Achievements

In this study, we clarified some of the roles of rostral ventromedial medulla (RVM) in the central descending pain control for pain mechanisms in the orofacial region. Since there are many serotonin (5-HT)-ergic neurons in the RVM that project to the trigeminal nucleus and control pain, to clarify their function, we created animals in which 5-HT-ergic neurons in the RVM were selectively deleted using the anti-serotonin transporter-Saporin. As a result, nociceptive dynamics of the animals were examined, and pain was alleviated compared to the control group. These results indicate that 5-HT-ergic neurons in the RVM have a pain-promoting function.

Free Research Field

口腔顔面痛

Academic Significance and Societal Importance of the Research Achievements

神経毒と結合した抗IgG セロトニン（5-HT）トランスポーターを用い、延髄吻腹内側部（RVM）の5-HT作動性ニューロンを選択的に削除した（Anti-SERT-Sap）モデルを作成した。そのモデルを使用し、ホルマリン（FC）テストを行った結果、侵害受容性疼痛関連行動数が減少し、三叉神経核尾側亜核のc-Fos陽性細胞数も減少したことにより、RVMの5-HT作動性ニューロンが侵害受容機能を有することを示した。また5-HT作動性ニューロンは神経障害性疼痛モデルで活動性の増加を認め、中枢内下行性疼痛制御に重要な役割を果たす根拠の一端を示した。これらの結果は社会的意義があり、今後の研究へと波及する。