Susceptibility of young adult and old rats to noise-induced hearing loss
Susceptibility of young adult and old rats to noise-induced hearing loss
复制标题
DOI：
10.1159/000069476
复制
发表时间：
2003-05-01
影响因子：
1.6
通讯作者：
Sohmer, H
中科院分区：
文献类型：
--
作者：
Fraenkel, R;Freeman, S;Sohmer, H
这项研究旨在测试老年大鼠是否表现出老年性耳聋的迹象，以及它们是否会与年轻成年大鼠相比，对噪音导致的听力损失具有类似或更多或更少的易感性。老年(24月龄)和年轻成年(3~4月龄)Wistar大鼠暴露在11dBSPL的宽带噪声中1h(产生暂时性阈值漂移)或3d(12h噪声/12h安静；永久移位)。分别于暴露前和暴露后测定听性脑干反应(ABR)、失真产物耳声发射(DPOAEs)和瞬时诱发耳声发射(TEOAEs)。在首次记录时(暴露前)，老年大鼠与青年大鼠相比，平均ABR阈值升高较小，I波(WI)波幅降低，WI潜伏期缩短，峰间间隔延长。老年大鼠在刺激后2ms的TEOAE反应中，DPOAE波幅和峰间波幅均有不同程度的降低，但2~4 kHzTEOAE能量含量无明显变化。这些都是老年大鼠耳聋的迹象。噪声暴露引起老年大鼠和青年大鼠ABR阈值升高，DPOAE波幅和TEOAE能量含量降低，这在老年和青年大鼠中都是相似的。他们从噪音造成的损失中恢复的情况也是相似的。因此，这项研究的结果表明，老年和年轻成年大鼠，至少在考虑到与临床相关的噪声暴露强度和持续时间时，同样容易受到噪声暴露的影响。版权所有(C)2003 S.Karger AG，巴塞尔。
This study was designed to test whether old rats show signs of presbyacusis and whether they would be either similarly or more or less susceptible to noise-induced hearing loss than young adult rats. Old (24 months) and young adult (3-4 months) Wistar rats were exposed to a broad-band noise of 113 dB SPL for a duration of 1 h (producing temporary threshold shifts) or 3 days (12 h noise/12 h quiet; permanent shifts). Auditory brainstem response (ABR), distortion product otoacoustic emissions (DPOAEs) and transient evoked otoacoustic emissions (TEOAEs) were measured before and after exposure. At the initial recording (before exposure), old rats demonstrated a small mean ABR threshold elevation, a reduction in amplitude of wave I (WI), a shortening of WI latency and a prolongation of the interpeak interval between WI and WIV, as compared to the young rats. The old rats also demonstrated a small DPOAE amplitude reduction and a reduction of peak-to-peak amplitude in the TEOAE response 2 ms after stimulus, but no reduction in TEOAE energy content between 2 and 4 kHz. These are signs of presbyacusis in the old rats. The noise exposures caused elevations in ABR threshold and reductions in DPOAE amplitude and TEOAE energy content that were similar in both the old and young rats. Their recovery from the noise-induced loss was also similar. Thus, the results of this study show that old and young adult rats, at least when considering clinically relevant intensities and durations of noise exposure, are equally susceptible to the effects of the exposure. Copyright (C) 2003 S. Karger AG, Basel.