Cochlear synaptopathy in hearing loss due to retrolabyrinthine pathology

Research Project

Project/Area Number	15K10741
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Multi-year Fund
Section	一般
Research Field	Otorhinolaryngology
Research Institution	Tohoku University
Principal Investigator	NOGUCHI Naoya 東北大学, 医学系研究科, 非常勤講師 (20333792)
Co-Investigator(Kenkyū-buntansha)	香取幸夫東北大学, 医学系研究科, 教授 (20261620) 川瀬哲明東北大学, 医工学研究科, 教授 (50169728)
Project Period (FY)	2015-04-01 – 2019-03-31
Project Status	Completed (Fiscal Year 2018)
Budget Amount *help	¥4,810,000 (Direct Cost: ¥3,700,000、Indirect Cost: ¥1,110,000) Fiscal Year 2017: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000) Fiscal Year 2016: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000) Fiscal Year 2015: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
Keywords	難聴 / Hidden Hearing Loss / マスキング / 音響性聴覚障害 / Hidden hearing loss / 神経科学 / 蝸牛神経 / 後迷路性難聴
Outline of Final Research Achievements	In the present study, we examined (1) cochlear nerve pathology in guinea pigs with hearing loss due to kanamycin ototoxity, (2) pathologic masking function in mouse model of sound induced hearing loss and (3) the possible involvement of cochlear synaptopathy in clinical cases after the recovery from acute unilateral sensorineural hearing loss and in those with unilateral tinnitus. Consequently, the following results were obtained; i.e., a) it is suggested that cochlear synaptopathy could be involved in several types of hearing loss other than the sound-induced hearing loss and age-related deafness (those have been already well-known to cause cochlear synaptopathy), b) the deterioration of masking and loudness functions would be a good indicator to diagnose the possible involvement of cochlear synaptopathy in actual clinical cases.
Academic Significance and Societal Importance of the Research Achievements	従来報告されている音響性聴覚障害、加齢性聴覚障害以外の難聴病理にも蝸牛神経シナプス病理の関与が示唆されることを示したこと、また、蝸牛神経シナプス病理の臨床診断法について提言を行うことができたこと