实验性诱导声创伤模型中最方便的噪声暴露持续时间

文献信息

中文摘要

目的： 不同实验性声创伤模型在给定噪声的持续时间、强度和频率方面存在很大差异。本研究旨在为声创伤模型的标准化发展做出贡献，尤其是在噪声暴露持续时间方面。
方法： 将30只大鼠按噪声持续时间随机分为三组；以110 dB SPL、4 kHz窄带噪声仅作用于右耳，分别为30分钟（I组）、1小时（II组）和2小时（III组）。左耳作为对照。通过畸变产物耳声发射和听性脑干反应测试对所有大鼠双耳的听力功能进行电生理评估。听力测试后，采用免疫组织化学和末端脱氧核苷酸转移酶dUTP缺口末端标记法对60个耳蜗进行染色。
结果： 所有组受创伤右耳的听阈均升高（P < 0.001）。III组所获得的差异高于其他组（P = 0.002）。仅在III组中，左耳也观察到听阈升高，尤其是在创伤后第7天，具有显著性趋势（P = 0.083）。在免疫组织学染色中，观察到非常强的反应，尤其是在III组的内毛细胞和外毛细胞中。
结论： 通过插入式耳机施加110 dB SPL窄带噪声2小时产生了最可重复的永久性声创伤，这已通过听力学和组织病理学发现得到证实。此外，在未受创伤的耳中观察到暂时性阈移，突显了在设计未来实验研究时考虑对侧效应的重要性。

英文摘要

OBJECTIVE: There is a large variation in the duration, intensity, and frequency of the given noise among different experimental acoustic trauma models. The aim of this study is to contribute to the development of standardization in acoustic trauma models, especially in terms of noise exposure duration.
METHODS: Thirty rats were randomly divided into three groups according to noise duration; 110 dB SPL narrow-band noise at 4 kHz was applied to only the right ears for 30 min (group I), 1 h (group II), and 2 h (group III). The left ears were kept as control. Hearing function of both ears of all rats was evaluated with distortion product otoacoustic emission and auditory brainstem response tests electrophysiologically. After the hearing tests, 60 cochleae were stained using immunohistochemistry and terminal deoxynucleotidyl transferase dUTP nick-end labeling methods.
RESULTS: Hearing thresholds in the traumatized right ears in all groups were increased ( P < 0.001). The difference obtained in group III was higher than in the other groups ( P =  0.002). An increase in the hearing thresholds also was observed in the left ears, especially on the 7th post-traumatic day, only for group III, with a trend toward significance ( P =  0.083). In the immunohistological staining, a very strong reaction was observed, especially in the inner and outer hair cells of group III.
CONCLUSION: Application of 110 dB SPL narrow-band noise for 2 h via insert earphones produced the most reproducible permanent acoustic trauma, as confirmed by both audiological and histopathological findings. In addition, a temporary threshold shift was observed in the untraumatized ear, highlighting the importance of considering contralateral effects when designing future experimental studies.