噪声所致听力损失现象的物种差异及可能生理机制研究进展

噪声广泛存在于人和动物的生活环境中，从无脊椎动物到哺乳动物乃至人类，都会受到噪声的负面影响. 强烈的噪声会损伤听觉系统的结构和功能，引起噪声性听力损失（noise-induced hearing loss，NIHL）. 本文对噪声性听力损失的类型、影响因素、噪声所致不同程度听力损失形成的可能机制进行了总结，发现NIHL主要与突触结构肿胀、谷氨酸引起的可逆兴奋性中毒以及活性氧引起的氧化应激、细胞凋亡、带状体损伤、α激动型鸟嘌呤核苷酸结合蛋白（guanine nucleotide binding protein alpha stimulating，GNAS）基因的mRNA及其上游lncRNA Sept7的表达量上调等因素有关. 比较噪声暴露后不同物种听力损失情况的差异，发现鱼类和鸟类由于具有毛细胞再生能力而能够较快从听力损伤中恢复，啮齿类较容易受到噪声影响，而回声定位鲸类噪声暴露后的暂时性听觉阈移较小，非常有趣的是回声定位蝙蝠在噪声高强度暴露后未表现出暂时性听觉阈移的现象. 上述结论提示，对不同物种的比较生理研究可深入揭示NIHL机制，并为听力保护以及噪声所致的听力损伤后修复等提供理论参考.

Research Progress in Species Differences and Underlying Physiological Mechanism of Noise-induced Hearing Loss

Noise widely exists in animals and human everyday life, it has negative influence on animals from invertebrates to mammals, and even human beings. High level noise can cause damage to auditory structure and function, decrease auditory neural sensitivity and behavioral acuity, and even lead to noise-induced hearing loss (NIHL). In this review, we summarized influence impacts and classification of NIHL, and possible mechanisms underlying the NIHL. Previous research on NIHL showed that the NIHL was related to postsynaptic terminals swelling, reversible excitotoxicity induced by glutamate and reactive oxygen species (ROS) evoked oxidative stress, cell apoptosis, synaptic ribbons damage and increasing express level of mRNA of guanine nucleotide binding protein alpha stimulating (GNAS) and their upstream lncRNAs Sept7. We further compared the differences in hearing loss among different species, and found that all species exhibited various degree of hearing loss after noise exposure excepting the echolocation bats. The fishes and birds can quickly recover from the hearing damage because their hair cells have the ability to regenerate. Comparing with the rodent which is more susceptive to noise influence, the echolocation cetacean have a small temporary threshold shift (TTS) after high intensity noise exposure, and the specialized inner ear structure is thought to be the possible reason. It is interesting that the echolocation bat do not exhibit TTS even exposed to high intensity noise, which is thought to be an adaption to their living environment, and forward studies on the underlying neurophysiological mechanisms will help us fully understand and solve the NIHL. These conclusions indicated that comparative physiological study on different species can help us deeply reveal the mechanism underlying NIHL, and provide a reference for hearing protection and repairing of noise induced hearing loss.