脑震荡模型Wistar大鼠畸变产物耳声发射的改变

THE CHANGES OF DISTROTION PRODUCT OTOACOUSTIC EMISSIONS IN AN ANIMAL MODEL OF CEREBRAL CONCUSSION OF WISTAR RATS

目的观察脑震荡模型Wistar大鼠畸变产物耳声发射(distrotion product otoacoustic emissions,DPOAE)的改变。方法对40只(40耳)健康无耳疾雄性Wistar大鼠随机分为A(正常)、B(撞击后30 min)、C(撞击后1 h)、D(撞击后1 d)四组,利用自由落体装置建立大鼠脑震荡模型。测试均在隔声室内进行。以上四组分别进行DPOAE幅值测试及听性脑干反应(auditory brainstem responses,ABR)阈值测试。结果A、B、C、D四组DPOAE检测结果显示,在频率2 kHz时的DPOAE幅值分别为:A组-(4.40±9.20),B组-(10.50±6.19),C组-(14.30±4.88),D组-(13.50±5.48)。正常组和撞击后的三组间比较差异有显著性(P<0.05),而撞击后30min,1 h及1 d三组间比较DPOAE幅值间差异无显著性(P>0.05)。在其他频率区,四组比较差异无显著性(P>0.05)。而且正常组与撞击后三组间比较,ABR阈值升高。结论撞击后大鼠DPOAE幅值在频率2 kHz时下降。DPOAE幅值的改变说明脑震荡对耳蜗外毛细胞有一定的影响。

Objective To observe the changes of distrotion product otoacoustic emissions （DPOAE） in an animal model of cerebral concussion of Wistar rats. Methods Forty（40 ear） healthy male Wistar rats were randomly divided into four groups which are A （normal）, B（30 minutes after rammed）, C（1 hour after rammed）, and D（1 day after rammed）. To set up an animal model of cerebral concussion about Wistar rats by utilizing the device of falling object. Every group＇s dates were measured in the environment of acoustic insulation. The amplitudes of DPOAE and threshold values of Auditory Brainstem Responses were measured separately in the four groups of A, B, C, and D. Results The amplitudes of DPOAE at 2kHz was stable, and the statistics were -（4.40±9.20） in normal rats（A group）. The statistics of amplitudes in the other three groups（B, C, D group） were separately： B, -（10.50±6.19）,C, --（14.30±4.88） ,D, - （13.50±5.48）. The results indicated that the statistically significant decrease of DPOAE was observed at 2 kHz between normal group and the three groups after rammed（ P 〈0.05）. But fewer changes were observed among the three groups after rammed（ P 〉0.05）. At the other frequency, fewer significance were observed between the control group and the three groups after rammed（ P 〉0.05）. Besides, the threshold values have an increase when the control group （normal group） was compared with the three groups after rammed. Conclusion The amplitudes of the three groups after rammed compared with the normal group were decreased at 2 kHz. These results indicate that ramming might damage the cochlear hair cells of rats, especially out hair cells.