Physiological and Morphological Assessment of the Saccule in Guinea Pigs After Noise Exposure
Physiological and Morphological Assessment of the Saccule in Guinea Pigs After Noise Exposure
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DOI：
10.1001/archotol.134.10.1099
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发表时间：
2008-10-01
影响因子：
--
通讯作者：
Young, Yi-Ho
中科院分区：
文献类型：
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作者：
Hsu, Wei-Chung;Wang, Jung-Der;Young, Yi-Ho
目的：为了研究球囊是否表现出暂时或永久性的功能丧失，类似于噪声暴露后豚鼠听性脑干反应（ABR）的阈值偏移。设计：随机饲养的豚鼠分为3组：一（短期噪声暴露，30分钟，n = 15），B（长期噪声暴露，40小时，n = 9），和C实验地点：大学医院。主要结果测量：所有动物进行前庭诱发肌源性电位（VEMP）和ABR测试。分析比较了噪声暴露后VEMP和ABR反应的时间变化。结果：A组在短时间噪声暴露后，VEMP暂时性丧失和ABR阈值偏移分别在2 d和4 d恢复，VEMP恢复时间比ABR阈值恢复时间早2 d;相反，在B组中，78%和83%的耳分别表现出永久性VEMP损失和ABR阈值偏移，在长期噪声暴露后10天。在C组中，所有动物在整个研究期间均显示正常的VEMP和ABR。光镜和电镜研究证实，损失的VEMPs与球囊lesions.Conclusions：球囊可以表现出暂时性或永久性的功能丧失类似于听力阈值的变化，在豚鼠噪声暴露后。短期噪声暴露损伤后，VEMP的恢复先于听阈的恢复。相反，长期噪声暴露后的永久性VEMP损失可能反映了永久性听阈偏移。
Objective: To investigate whether the saccule exhibits temporary or permanent functional loss resembling threshold shifts in auditory brainstem response (ABR) of guinea pigs following noise exposure.Design: Randomly bred guinea pigs were divided into 3 groups: A (short-term noise exposure, 30 minutes, n = 15), B (long-term noise exposure, 40 hours, n = 9), and C (no noise exposure, n = 5).Setting: University hospital.Main Outcome Measures: All animals underwent vestibular-evoked myogenic potential (VEMP) and ABR tests. Chronological changes of VEMP and ABR responses following noise exposure were analyzed and compared. After audiovestibular function testing, animals were killed for morphological study with light and electron microscopy.Results: In group A, temporary VEMP loss and ABR threshold shifts recovered 2 and 4 days, respectively, after short-term noise exposure, with an interval of 2 days earlier in the recovery of VEMPs than that of ABR thresholds. In contrast, in group B, 78% and 83% of the ears exhibited permanent VEMP loss and ABR threshold shifts, respectively, 10 days following long-term noise exposure. In group C, all animals showed normal VEMPs and ABRs throughout the study period. Light and electron microscopic studies confirmed that loss of VEMPs correlated with saccular lesion.Conclusions: The saccule can exhibit temporary or permanent functional loss resembling hearing threshold shifts in guinea pigs following noise exposure. Recovery of VEMP precedes restoration of hearing threshold after damage from short-term noise exposure. Conversely, permanent VEMP loss after long-term noise exposure may reflect permanent hearing threshold shifts.