DIFFERENTIAL SUSCEPTIBILITY TO NOISE-INDUCED PERMANENT THRESHOLD SHIFT BETWEEN ALBINO AND PIGMENTED GUINEA-PIGS
DIFFERENTIAL SUSCEPTIBILITY TO NOISE-INDUCED PERMANENT THRESHOLD SHIFT BETWEEN ALBINO AND PIGMENTED GUINEA-PIGS
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DOI：
10.1016/0378-5955(86)90177-2
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发表时间：
1986-01-01
期刊：
影响因子：
2.8
通讯作者：
CREEL, DJ
中科院分区：
文献类型：
--
作者：
CONLEE, JW;ABDULBAQI, KJ;CREEL, DJ
耳蜗黑色素水平降低与听觉敏感性增加、听觉疲劳水平增加和对噪声性听力损失的易感性增加有关，这一证据促使我们研究了噪声暴露对白化病和有色英国短毛豚鼠耳蜗颤噪音（CM）的影响。在暴露于126 dB噪声45 min之前、90 min和7 d后，从圆窗记录CM。确定了四个纯音的CM的第一个可检测到的激发的持续时间，并通过在CM和电压翻转中产生最大电压幅度的强度水平以10 dB的步长测量每个耳蜗的输出电压。这一分析表明：（1）噪声暴露前，白化病豚鼠的听阈显著低于有色豚鼠，（2）噪声暴露后90 min，两组豚鼠的听阈均升高至相当水平;（三）有色豚鼠暴露于噪声后7天CM阈值有可靠的恢复，而白化豚鼠暴露于噪声后90分钟和7天CM阈值仍有相同程度的升高噪音后;（4）噪声暴露后90 min，白化病豚鼠耳蜗的最大输出电压明显低于有色豚鼠。这些结果表明，白化病豚鼠比有色豚鼠更容易受到高强度噪声的耳毒性作用。越来越多的证据表明，耳蜗功能的某些方面涉及黑色素，缺乏黑色素可能会导致听觉异常。黑色素沉着减少也可能导致噪声引起的阈值偏移和噪声引起的听力损失的个体差异。
Evidence that reduced levels of cochlear melanin are associated with increased auditory sensitivity, increased levels of auditory fatigue and an increased susceptibility to noise-induced hearing loss led us to investigate the effects of noise exposure on the cochlear microphonic (CM) in albino and pigmented English shorthair guinea pigs. CMs were recorded from the round window prior to and at 90 min and 7 days after exposure to 45 min of 126 dB noise. Thresholds for the first detectable elicitation of the CM for four pure tones were determined and the output voltage of each cochlea was measured in 10 dB steps through intensity levels which produced a maximum voltage amplitude in the CM and voltage rollover. This analysis demonstrated that: (1) albino guinea pigs displayed significantly lower auditory thresholds than did pigmented animals before exposure to noise; (2) thresholds were elevated to comparable levels in both groups 90 min after noise exposure;(3) pigmented guinea pigs showed a reliable recovery in CM thresholds 7 days after exposure to noise while thresholds in the albinos remained elevated to the same degree at both 90 min and 7 days after noise; (4) 90 min after noise exposure, the maximum voltage output of albino cochleas was significantly less than that recorded from the cochleas of the pigmented guinea pigs. These results demonstrate that albino guinea pigs are more susceptible to the ototoxic effects of high intensity noise than pigmented guinea pigs. Converging evidence indicates that some aspects of cochlear function involve melanin pigment and that its absence may produce auditory abnormalities. Reduced melanin pigmentation may also contribute to such phenomena as noise-induced threshold shifts and individual differences in noise-induced hearing loss.