Inspection of the excessive revision of the auditory cortex on the ear ringing animal observed by optical recording

2022 Fiscal Year Final Research Report

• Project/Area Number: 17K11336
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Otorhinolaryngology
• Research Institution: University of the Ryukyus
• Principal Investigator: Hosokawa Yutaka 琉球大学, 医学部, 非常勤講師 (80181501)
• Project Period (FY): 2017-04-01 – 2023-03-31
• Keywords: 耳鳴り / 光学的計測 / 聴覚皮質 / FM 音

Outline of Final Research Achievements

Many publications have shown that the application of salicylate at high doses induces reversible tinnitus in human and animals. We analyzed how the acoustic information processing in the auditory cortex changes in the state of acute tinnitus using cortical optical measurements. Repeated sounds were added to investigate the timing processing of sounds in the auditory cortex, and FM sounds were added to investigate the frequency processing. We examined the frequency band response analysis of the cortical analysis to FM sound during the transitional period after salicylic acid addition. Thirty minutes after salicylic acid overdose, the frequency band responses to downward FM sound were synchronized, and the mid-frequency band responses were restored after a decrease in amplitude in all frequency band responses. Only the off response remained for downward FM sound.

Free Research Field

聴覚生理学

Academic Significance and Societal Importance of the Research Achievements

耳鳴りは自覚的な生理現象で、多くの原因があり、その発生機序はよくわかっていない。サリチル酸過剰付加して作成した耳鳴り動物を研究することにより、末梢でのメカニズムが解明されてきた。今回は、電位感受性色素により聴覚領の電位変化を直接観察した。音の周波数分析や時間処理において、聴覚野の過剰補正による耳鳴りが、左右の聴覚特性の同一化や音周波数の弁別の低下をもたらしたことは、耳鳴りの発生により脳状態が変化したことを示唆する。この研究は、耳鳴りの緩和や治療に貢献すると考えられる。