Ingham N J, Thornton S K, Comis S D, Withington D J
Department of Physiology, Worsley Medical and Dental Building, University of Leeds, UK.
Acta Otolaryngol. 1998 Sep;118(5):673-80. doi: 10.1080/00016489850183160.
The auditory brainstem response (ABR) technique was used to investigate potential dysfunctions in the auditory brainstem of the pigmented guinea pig (Cavia porcellus) associated with biological ageing. Animals aged from 58 days to 4 years 3 months were tested. ABRs were recorded at stimulation intensities from 85 dB HL to -10 dB HL. The auditory thresholds were found to undergo marked elevations in old animals, by an average of 32 dB. From the traces obtained, four positive deflection waves were reliably recorded. The latency of each of the four waves was evaluated at different stimulation intensities in guinea pigs of different ages. Although there was a trend for the latencies to increase in old age, these differences were not statistically significant. Similarly, there were no significant age-related changes in the inter-peak intervals. The latency/intensity functions of the four waves produced parallel curves. However, the curve from the old age group was shifted to the right, by an average of 35 dB, indicative of conductive hearing loss. There was no evidence of retro-cochlear hearing loss. Therefore, it appears that the threshold elevations in the old animals can be accounted for by conductive hearing loss, presumably in the middle ear. In 24% of the old animals tested, no ABR could be elicited. It would appear that these animals had suffered severe sensorineural hearing loss.
采用听觉脑干反应（ABR）技术，研究有色豚鼠（豚鼠）听觉脑干与生物衰老相关的潜在功能障碍。对年龄从58天至4岁3个月的动物进行了测试。在85 dB HL至-10 dB HL的刺激强度下记录ABR。发现老年动物的听觉阈值显著升高，平均升高32 dB。从获得的波形中，可靠地记录到四个正向偏转波。在不同年龄的豚鼠中，于不同刺激强度下评估这四个波中每个波的潜伏期。尽管老年豚鼠的潜伏期有增加趋势，但这些差异无统计学意义。同样，峰间期也没有与年龄相关的显著变化。这四个波的潜伏期/强度函数产生平行曲线。然而，老年组的曲线向右偏移，平均偏移35 dB，表明存在传导性听力损失。没有蜗后听力损失的证据。因此，老年动物的阈值升高似乎可由传导性听力损失解释，推测是中耳的问题。在测试的老年动物中，24%无法引出ABR。看来这些动物患有严重的感音神经性听力损失。
