[高频听力损失对豚鼠低频区域时间处理的影响]

[Effect of high frequency hearing loss on the temporal processing in the low frequency regions of guinea pigs].

作者信息

Yu Xin, Wang Jian, Feng Yan-Mei, Yin Shan-Kai

机构信息

Department of Otorhinolaryngology Head and Neck Surger, Sixth Affiliated People's Hospital, Shanghai Jiao Tong University, Shanghai 200233, China.

出版信息

Zhonghua Er Bi Yan Hou Tou Jing Wai Ke Za Zhi. 2011 Feb;46(2):132-8.

PMID:21426708

Abstract

OBJECTIVE

To constitute the animal model of high frequency hearing loss and observer the temporal processing abilities of low frequency regions using prepulse inhibition of auditory startle response (gap-PPI).

METHODS

Ten guinea pigs were randomly grouped into two groups: the high frequency hearing loss group with six guinea pigs and the control group with four guinea pigs. The former group was exposed to 12 kHz tone at 110 dB SPL for 30 hours to establish the high frequency hearing loss above 8 kHz and the latter group received no stimulations. Before and two, four, six and eight weeks after noise exposure, gap-PPI and auditory brainstem response (ABR) were recorded in both groups. In the gap-PPI experiment, three different background noises as 0.5 - 2 kHz, 0.5 - 4 kHz and 0.5 - 8 kHz were applied to test the temporal gap.

RESULTS

High frequency hearing loss above 8 kHz was shown two weeks after noise exposure. The averaged ABR thresholds of 16 kHz, 32 kHz and 48 kHz were elevated about 55 dB and shown statistical significance compared to those before exposure (P < 0.05). No significant difference of ABR thresholds were shown between 1 kHz, 2 kHz, 4 kHz and 8kHz before and after noise exposure (P > 0.05). In the control group, the ABR thresholds remained stable during experiment. In the gap-PPI test, two weeks after noise exposure of 8 kHz, the experiment group showed attenuated inhibition ability and recovered gradually four weeks after noise exposure. No statistical differences of inhibition ability at time points of two, four, six and eight weeks after noise exposure of 4 kHz were detected when compared with that of pre-exposure. Under the background noise of 2 kHz, the inhibition ability attenuated and reached statistical significance at 6 - 8 weeks after noise exposure.

CONCLUSION

The high frequency hearing loss might induce an impairment of the temporal processing in the low frequency region.

摘要

目的

构建高频听力损失动物模型，采用听觉惊吓反应前脉冲抑制（间隙前脉冲抑制，gap-PPI）观察低频区域的时间处理能力。

方法

将10只豚鼠随机分为两组：高频听力损失组6只豚鼠，对照组4只豚鼠。前一组暴露于110 dB SPL的12 kHz纯音30小时，以建立8 kHz以上的高频听力损失，后一组不接受刺激。在噪声暴露前以及暴露后2、4、6和8周，两组均记录间隙前脉冲抑制和听性脑干反应（ABR）。在间隙前脉冲抑制实验中，应用三种不同的背景噪声，即0.5 - 2 kHz、0.5 - 4 kHz和0.5 - 8 kHz，来测试时间间隙。

结果

噪声暴露两周后出现8 kHz以上的高频听力损失。与暴露前相比，16 kHz、32 kHz和48 kHz的平均ABR阈值升高约55 dB，差异具有统计学意义（P < 0.05）。噪声暴露前后，1 kHz、2 kHz、4 kHz和8 kHz的ABR阈值无显著差异（P > 0.05）。对照组在实验期间ABR阈值保持稳定。在间隙前脉冲抑制测试中，8 kHz噪声暴露两周后，实验组的抑制能力减弱，噪声暴露四周后逐渐恢复。4 kHz噪声暴露后2、4、6和8周时间点的抑制能力与暴露前相比，未检测到统计学差异。在2 kHz背景噪声下，抑制能力减弱，在噪声暴露后6 - 8周达到统计学意义。