不同噪声暴露次数对C57小鼠听功能影响的研究

Research on Influence of Different Times of Noise Exposure on C57 Mice Hearing Function

目的通过噪声暴露构建C57小鼠不同程度的耳聋模型。方法听力正常小鼠随机分成对照组A,一次噪声暴露组B,二次暴露组C和三次暴露组D,白噪声100dBSPL持续2小时,二次和三次噪声暴露为隔日给声。噪声暴露组分别在噪声暴露前,和最后一次噪声暴露后的第1天,第7天和第14天进行ABR阈值测试,第14天Ⅰ波振幅测试和耳蜗组织切片,HE染色进行毛细胞和螺旋神经节细胞计数。结果噪声暴露后第1天和第7天ABR阈值有明显升高,但B组第7天已经呈现恢复状态,而C、D组则呈现渐进性加重趋势。第14天时,B组阈值已经完全恢复,而C、D组小鼠未能完全恢复正常。ABRI波振幅在B、C、D组均有不同程度的降低。各组小鼠耳蜗内毛细胞和螺旋神经节细胞计数无明显差异,单次噪声暴露外毛细胞无明显损失,但随暴露次数增多,损失逐渐加重。结论通过不同次数的噪声暴露,可以构建稳定的C57小鼠的隐匿性听力损失和噪声性耳聋动物模型。

Objective to build C57 mice model of different levels of hearing loss using noise exposure.Methods mice were randomly divided into control group A,single noise exposure group B,twice noise exposure group C and three times noise exposure group D.2 hour duration,100 dBSPL white noise was exposured a single time or on alternate days for 2 or 3 times.ABR threshold was tested before noise exposure,and 1,7,14 days after the last noise exposure,amplitude of waveⅠwas tested 14 days after the last noise exposure,cochlear section and HE stain was made to count hair cells and spiral ganglion cells.Results 1 and 7 days after noise exposure,ABR threshold increased significantly,but group B showed a partial recovery of ABR threshold on 7 days,while group C and D showed a serious trend.On 14th day,group B showed a total recovery of threshold compared with group C and D.WaveⅠamplitude decreased after noise exposure in all groups.Inner hair cell and spiral ganglion cell count has no obvious difference among the four groups,outer hair cells stay stable in group B,and were lost gradually with the exposure increase.Conclusion using different times of noise exposure,we can build C57 mice model of hidden hearing loss and noise-induced hearing loss.