Orexins modulate membrane excitability in rat trigeminal motoneurons

• Tanaka Susumu

  First Department of Oral and Maxillofacial Surgery, Graduate School of Dentistry, Osaka University

• Higuchi Masataka

  First Department of Oral and Maxillofacial Surgery, Graduate School of Dentistry, Osaka University

• Seki Soju

  First Department of Oral and Maxillofacial Surgery, Graduate School of Dentistry, Osaka University

• Enomoto Akifumi

  Department of Oral and Maxillofacial Surgery, Faculty of Medicine, Kindai University

• Kogo Mikihiko

  First Department of Oral and Maxillofacial Surgery, Graduate School of Dentistry, Osaka University

抄録

Orexins (Oxs) are multifunctional neuropeptides, secreted from the lateral hypothalamus, that stimulate feeding behavior and energy expenditure. In this study, the direct effects of Oxs on the membrane properties of trigeminal motoneurons (TMNs) were examined, which critically participate in the genesis of rhythmical oral motor activities underlying suckling and mastication. Sprague-Dawley rats (3-6 day-old) were used to obtain whole-cell patch-clamp recordings from TMNs. Bath application of Ox-A depolarized the membrane potential and induced inward current, wherein Na⁺ and Ca²⁺ were charge carriers. Transient receptor potential channel activation potentially contributed to current and voltage responses by way of Ox-A. Ox-A increased the peak amplitude and duration at half-amplitude of the medium-duration after hyperpolarization following the action potential. The interspike frequency of steady-state firings during repetitive discharge was increased, along with a shift in the frequency-current relationship occurring toward the left. Extracellular and intracellular Ca²⁺ were involved in regulating modulatory effects, but a requisite level of intracellular Ca²⁺ was not essential for Ox-induced upregulation of the interspike frequency. Ox-A also enhanced conditional bursting induced by N-methyl-d-aspartate and 5-HT, suggesting it participates in modulating TMNs’ discharge patterns during various oral motor activities.

収録刊行物

• Ｊｏｕｒｎａｌ　ｏｆ　Ｏｒａｌ　Ｓｃｉｅｎｃｅ

  Ｊｏｕｒｎａｌ　ｏｆ　Ｏｒａｌ　Ｓｃｉｅｎｃｅ 62 (3), 265-270, 2020

  日本大学歯学部

キーワード

• conditional bursting
• neuropeptide
• orexin
• transient receptor potential channel
• trigeminal motoneuron

詳細情報

• CRID: 1390566775145726336
• NII論文ID: 130007863790
• DOI: 10.2334/josnusd.19-0141
• ISSN: 18804926
• ISSN: 13434934
• PubMed: 32493863
• Web Site: https://www.jstage.jst.go.jp/article/josnusd/62/3/62_19-0141/_pdf
• 本文言語コード: en
• データソース種別:
  • JaLC
  • Crossref
  • PubMed
  • CiNii Articles
  • KAKEN
• 抄録ライセンスフラグ: 使用不可