Establishment of an experimental tinnitus animal model for the new treatment of tinnitus

2022 Fiscal Year Final Research Report

• Project/Area Number: 18K09384
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 56050:Otorhinolaryngology-related
• Research Institution: Nara Medical University
• Principal Investigator: YAMASHITA AKINORI 奈良県立医科大学, 医学部, 学内講師 (50588522)
• Co-Investigator(Kenkyū-buntansha): 北原 糺 奈良県立医科大学, 医学部, 教授 (30343255)
• Project Period (FY): 2018-04-01 – 2023-03-31
• Keywords: 耳鳴 / 漢方薬 / 動物モデル / c-fos

Outline of Final Research Achievements

We replicated a previously reported salicylic acid -induced tinnitus animal model and determined the conditions under which the most tinnitus behavior was observed. In this animal model, tinnitus behavior was suppressed in the tinnitus rats model induced by salicylic acid which were given the Japanese traditional herbal medicine(Goshajinkigan), as compared to those which were given distilled water.
Next, the effects of Goshajinnkigan on the brain were examined using c-Fos, a measure of neural activity. In the primary auditory cortex, dorsal secondary auditory cortex, dorsal cochlear nerve nucleus, and central nucleus of the inferior colliculus, Goshajinkigan suppressed the salicylic acid-induced increase in the number of c-Fos-expressing cells. It was found that Goshajinkigan may suppress tinnitus by inhibiting neural activity in these regions.

Free Research Field

聴覚医学

Academic Significance and Societal Importance of the Research Achievements

本研究により牛車腎気丸がサリチル酸誘発耳鳴に対して動物行動学的、免疫組織化学的な検討の両方で抑制効果を及ぼすことを示した。これまで漢方薬の耳鳴への効果を動物実験により検証されたことはなく、世界で初めての試みであった。本研究は牛車腎気丸の耳鳴への有用性の根拠となるものであり、耳鳴治療法の確立の一助となりえるものである。また、耳鳴への内服薬の効果を検証する動物実験のモデルケースとなりうるもので、今後、別の内服薬や別の耳鳴を検討する研究につなげることも可能となる。