Suzuro Hitomi1, Kentaro Ono2, Kanako Miyano3, Yojiro Ota4, Yasuhito Uezono5, Motohiro Matoba6, Sachiko Kuramitsu7, Kiichiro Yamaguchi8, Kou Matsuo9, Yuji Seta10, Nozomu Harano11, Kiyotoshi Inenaga12. 1. Division of Physiology, Kyushu Dental University, 2-6-1 Manazuru, Kokurakita-ku, Kitakyushu, Fukuoka 803-8580, Japan. Electronic address: r11hitomi@fa.kyu-dent.ac.jp. 2. Division of Physiology, Kyushu Dental University, 2-6-1 Manazuru, Kokurakita-ku, Kitakyushu, Fukuoka 803-8580, Japan. Electronic address: ono@kyu-dent.ac.jp. 3. Division of Cancer Pathophysiology, National Cancer Center Research Institute, 5-1-1, Tsukiji, Chuo-ku, Tokyo 104-0045, Japan. Electronic address: kmiyano@ncc.go.jp. 4. Division of Dentistry and Oral Surgery, Shizuoka Cancer Center Hospital and Research Institute, 1007 Shimonagakubo, Nagaizumi-cho, Sunto-gun, Shizuoka 411-8777, Japan. 5. Division of Cancer Pathophysiology, National Cancer Center Research Institute, 5-1-1, Tsukiji, Chuo-ku, Tokyo 104-0045, Japan. Electronic address: yuezono@ncc.go.jp. 6. Division of Palliative Medicine and Psycho-Oncology Palliative Care Team, National Cancer Center, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan. 7. Division of Physiology, Kyushu Dental University, 2-6-1 Manazuru, Kokurakita-ku, Kitakyushu, Fukuoka 803-8580, Japan. 8. Division of Physiology, Kyushu Dental University, 2-6-1 Manazuru, Kokurakita-ku, Kitakyushu, Fukuoka 803-8580, Japan; Division of Dental Anesthesiology, Kyushu Dental University, 2-6-1 Manazuru, Kokurakita-ku, Kitakyushu 803-8580, Japan. Electronic address: letiziare.une.524@gmail.com. 9. Division of Pathology, Kyushu Dental University, 2-6-1 Manazuru, Kokurakita-ku, Kitakyushu, Fukuoka 803-8580, Japan. Electronic address: kou@kyu-dent.ac.jp. 10. Division of Anatomy, Kyushu Dental University, 2-6-1 Manazuru, Kokurakita-ku, Kitakyushu, Fukuoka 803-8580, Japan. Electronic address: yujiseta@kyu-dent.ac.jp. 11. Division of Dental Anesthesiology, Kyushu Dental University, 2-6-1 Manazuru, Kokurakita-ku, Kitakyushu 803-8580, Japan. Electronic address: harano@kyu-dent.ac.jp. 12. Division of Physiology, Kyushu Dental University, 2-6-1 Manazuru, Kokurakita-ku, Kitakyushu, Fukuoka 803-8580, Japan. Electronic address: ine@kyu-dent.ac.jp.
Abstract
BACKGROUND: Stomatitis induces severe and painful hypersensitivity to pungency and physical contact during meals. Many studies have used anesthetized animals to examine evoked nociception in the oral mucosa, but no reports have used traditional behavioral assays to evaluate nociception in conscious animals. NEW METHODS: We developed two new methods of applying chemical or mechanical stimulation directly to the oral mucosa of the mandibular vestibule of conscious rats. Nociceptive evaluations were performed by measuring facial grooming time and the head withdrawal threshold to von Frey stimulations. (1) For the intraoral dropping method, rat mucosa was transiently exposed by hand, and a drop of a pungent solution was applied. (2) For the stable intraoral opening method, rat mucosa was long-term exposed following piercing surgery of the mental skin after habitual training for 2-3 weeks. RESULTS: In the intraoral dropping method, the application of 100 μM capsaicin or 100 mM allyl isothiocyanate prolonged mouth-rubbing time. Capsaicin-induced mouth-rubbing time was further enhanced following the development of an acetic acid-induced ulcer. The stable intraoral opening method enabled stable measurements of the mechanical withdrawal threshold in the oral mucosa of conscious rats. Ulcer development decreased the mechanical threshold, whereas topical lidocaine treatment increased the threshold. COMPARISON WITH EXISTING METHODS: These new methods enable the evaluations of motivational nocifensive behaviors in response to intraoral stimulations without any anesthetic effects. CONCLUSIONS: The intraoral dropping and stable intraoral opening methods can be used in combination with traditional behavioral assays to evaluate nociception in the oral mucosa of conscious rats.
BACKGROUND:Stomatitis induces severe and painfulhypersensitivity to pungency and physical contact during meals. Many studies have used anesthetized animals to examine evoked nociception in the oral mucosa, but no reports have used traditional behavioral assays to evaluate nociception in conscious animals. NEW METHODS: We developed two new methods of applying chemical or mechanical stimulation directly to the oral mucosa of the mandibular vestibule of conscious rats. Nociceptive evaluations were performed by measuring facial grooming time and the head withdrawal threshold to von Frey stimulations. (1) For the intraoral dropping method, rat mucosa was transiently exposed by hand, and a drop of a pungent solution was applied. (2) For the stable intraoral opening method, rat mucosa was long-term exposed following piercing surgery of the mental skin after habitual training for 2-3 weeks. RESULTS: In the intraoral dropping method, the application of 100 μM capsaicin or 100 mM allyl isothiocyanate prolonged mouth-rubbing time. Capsaicin-induced mouth-rubbing time was further enhanced following the development of an acetic acid-induced ulcer. The stable intraoral opening method enabled stable measurements of the mechanical withdrawal threshold in the oral mucosa of conscious rats. Ulcer development decreased the mechanical threshold, whereas topical lidocaine treatment increased the threshold. COMPARISON WITH EXISTING METHODS: These new methods enable the evaluations of motivational nocifensive behaviors in response to intraoral stimulations without any anesthetic effects. CONCLUSIONS: The intraoral dropping and stable intraoral opening methods can be used in combination with traditional behavioral assays to evaluate nociception in the oral mucosa of conscious rats.
Authors: Ya-Nan Fu; Yongsan Li; Bo Deng; Yingjie Yu; Fang Liu; Lei Wang; Guang Chen; Lei Tao; Yen Wei; Xing Wang Journal: Bioact Mater Date: 2021-06-23
Authors: Tuti Kusumaningsih; Anis Irmawati; Diah Savitri Ernawati; Chiquita Prahasanti; Mohammed Aljunaid; Sarah Amelia Journal: Vet World Date: 2021-05-23