Elucidation of the swallowing neural network by optogenetics

• Project/Area Number: 17H06695
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Single-year Grants
• Research Field: Prosthodontics/ Dental materials science and
• Research Institution: Niigata University
• Principal Investigator: Nagoya Kouta 新潟大学, 医歯学総合病院, 助教 (10806491)
• Project Period (FY): 2017-08-25 – 2019-03-31
• Project Status: Completed (Fiscal Year 2018)
• Budget Amount: ¥2,730,000 (Direct Cost: ¥2,100,000、Indirect Cost: ¥630,000); Fiscal Year 2018: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000); Fiscal Year 2017: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
• Keywords: 顎運動 / 咀嚼 / Phox2b / オレキシン / パッチクランプ / 顎運動制御 / Orexin / 摂食行動 / ブラキシズム / 嚥下神経機構 / 電気生理 / 嚥下 / CPG / 嚥下障害 / 口腔生理学 / 光遺伝学

Outline of Final Research Achievements

Phox2b is a member of transcription factors and essential for the development of the autonomic nervous system.We recently reported that Phox2b-expressing neurons are involved in the control of coordinated jaw-movements such as chewing and swallowing.In the present study, we investigated physiological changes of Phox2b-expressing neurons located at RdV by the administration of orexin known as regulating physiological functions such as feeding, and wake/sleep stabilities.The majority of Phox2b-expressing neurons were produced membrane depolarization during the application of orexin. However, orexin -induced membrane depolarization were prominently reduced in the presence of Orexin type2 antagonist. All Phox2b-expressing neurons exhibited reduction of firing rate by the administration of orexin. Taken together, present study suggests that orexin modulate passive membrane and firing properties of Phox2b-expressing RdV neurons.

Academic Significance and Societal Importance of the Research Achievements

摂食や睡眠・覚醒など様々な生理作用を有することが知られているオレキシンと顎運動制御に関与するPhox2bニューロンとの関連を電気生理学的に検証した。その結果、オレキシン投与はPhox2bニューロン特異的な変調効果を示すことがわかった。これは神経回路レベルでの摂食行動やブラキシズムにおけるメカニズム解明の一助となる可能性が考えられ、さらなる機能研究が望まれる。

Research Products

• [Journal Article] Involvement of the epithelial sodium channel in initiation of mechanically evoked swallows in anaesthetized rats (2019)
  • Author(s): Tsujimura Takanori、Ueha Rumi、Yoshihara Midori、Takei Eri、Nagoya Kouta、Shiraishi Naru、Magara Jin、Inoue Makoto
  • Journal Title: The Journal of Physiology Volume: 印刷中 Pages: 2949-2963
  • DOI: 10.1113/jp277895
  • Peer Reviewed
• [Journal Article] Effect of attention on chewing and swallowing behaviors in healthy humans (2019)
  • Author(s): Ashiga Hirokazu、Takei Eri、Magara Jin、Takeishi Ryosuke、Tsujimura Takanori、Nagoya Kouta、Inoue Makoto
  • Journal Title: Scientific Reports Volume: 9
  • DOI: 10.1038/s41598-019-42422-4
  • Peer Reviewed / Open Access
• [Journal Article] Effect of peripherally and cortically evoked swallows on jaw reflex responses in anesthetized rabbits. (2018)
  • Author(s): Suzuki T, Yoshihara M, Sakai S, Tsuji K, Nagoya K, Magara J, Tsujimura T, Inoue M.
  • Journal Title: Brain Research Volume: 印刷中 Pages: 19-28
  • DOI: 10.1016/j.brainres.2018.05.002
  • Peer Reviewed
• [Journal Article] Distinctive features of Phox2b-expressing neurons in the rat reticular formation dorsal to the trigeminal motor nucleus (2017)
  • Author(s): Nagoya K, Nakamura S, Ikeda K, Onimaru H, Yoshida A, Nakayama K, Mochizuki A, Kiyomoto M, Satoh F, Kawakami H, Takahashi K, Inoue T.
  • Journal Title: Neuroscience Volume: 358 Pages: 211-226
  • DOI: 10.1016/j.neuroscience.2017.06.035
  • Peer Reviewed
• [Presentation] Functional properties of Phox2b-expressing neurons located in the brainstem for chewing. (2018)
  • Author(s): Kouta Nagoya, Shiro Nakamura, Tomio Inoue, Makoto Inoue
  • Organizer: The 24th Annual Meeting of the Japanese Society of Dysphagia Rehabilitation The 3rd Japan-Korea Joint Symposium
  • Int'l Joint Research
• [Presentation] Distinctive properties of Phox2b neurons located in the rat reticular formation dorsal to the trigeminal motor nucleus. (2017)
  • Author(s): K. NAGOYA, S. NAKAMURA, K. IKEDA, H. ONIMARU, K. NAKAYAMA, A. MOCHIZUKI, F. SATO, A. YOSHIDA, K. KAWAKAMI, M. INOUE, T. INOUE.
  • Organizer: NEUROSCIENCE2017
  • Int'l Joint Research
• [Presentation] ラット三叉神経運動核の背側網様体に存在するPhox2b陽性ニューロンの電気生理学的および形態学的特性はPhox2b陰性ニューロンと異なる (2017)
  • Author(s): 那小屋公太, 中村史朗, 中山希世美, 望月文子, 佐藤文彦, 吉田 篤, 井上 誠, 井上富雄
  • Organizer: 第59回歯科基礎医学会学術大会
• [Presentation] 転写因子 Phox2b を発現する三叉神経運動核背側網様体ニューロンの 生理学的および形態学的特性. (2017)
  • Author(s): 那小屋公太, 中村史朗, 中山希世美, 望月文子, 吉田 篤, 井上 誠, 井上富雄
  • Organizer: 日本顎口腔機能学会 第 58 回学術大会