title: Protective effect of unilateral and bilateral ear plugs on noise-induced hearing loss: functional and morphological evaluation in animal model.
abstract: The aim of the following study is to evaluate immediate protective effect of ear plug from noise morphologically and functionally. An 1-month aged 29 male C57BL/6 mice. Subjects were divided into four groups as normal control(G1), bilaterally plugged group (G2), unilaterally plugged group (G3) and noise control group (G4) and later 3 groups were exposed to 110 sound pressure level white noise for 60 min. Immediately after noise exposure, audiologic tests were performed and cochlear morphology and expression levels of a-synuclein in the cochlea were investigated. There were no functional changes in G2 and plugged ears of G3 after noise exposure, whereas unplugged ears of G3 and G4 showed significant hearing loss. In morphological study, there were a significant degeneration of the organ of Corti and mean number and diameter of efferent buttons, in unplugged ears of G3 and G4. Plugged ears of G3 also showed mild changes in morphological study. Reduction of a-synuclein was observed at the efferent terminals or cochlear extracts after noise exposure. The protective effect of ear plug on noise exposure was proven morphologically and functionally in the animal model of noise-induced hearing loss. Further study on cellular or ultrastructural level with ear plug will be needed to reveal more precise mechanism.
authors: Dong-Kee
authors: DK
authors: Kim
authors: Yooyeon
authors: Y
authors: Park
authors: Sang-A
authors: SA
authors: Back
authors: Hong Lim
authors: HL
authors: Kim
authors: Hyu Eun
authors: HE
authors: Park
authors: Kyoung-Ho
authors: KH
authors: Park
authors: Sang Won
authors: SW
authors: Yeo
authors: Department of Otolaryngology-Head and Neck Surgery, The Catholic University of Korea, College of Medicine, Seoul, Korea.
authors: Shi-Nae
authors: SN
authors: Park
mesh_terms: D000818:Animals; D015153:Blotting, Western; D003051:Cochlea / Q000473:pathology; D004195:Disease Models, Animal; D004430:Ear Protective Devices; D016057:Evoked Potentials, Auditory, Brain Stem; D006317:Hearing Loss, Noise-Induced / Q000473:pathology* / Q000517:prevention & control*; D007150:Immunohistochemistry; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008855:Microscopy, Electron, Scanning