稳态白噪声对豚鼠螺旋器损伤的病理观察

豚鼠分别暴露于125 dB SPL 和132 dB SPL 的稳态白噪声中1h 后.即时、1、3、7、15和30 d进行螺旋器扫描电镜观察,发现主要是第3回和蜗顶螺旋器受损,表现为外毛细胞听毛肿胀、融合、倒伏、断裂和丧失,甚至外毛细胞缺如.暴露于132 dB 白噪声后即时有10 mm 耳蜗螺旋器受损,125 dB 为7 mm.前者有70%外毛细胞受损,后者为50%.噪声强度越大,螺旋器病变范围和外毛细胞受损数量增大,随存活时间延长而减轻.得到恢复的主要是轻度病变的外毛细胞,如静纤毛肿胀和融合,但中、重度损伤时静纤毛倒伏和消失未能恢复.白噪声暴露早期(125 dB 组暴露噪声后7 d,132 dB 组15 d),及时采用治疗措施的重要性.本文对噪声所致螺旋器损害的特点进行了讨论.

The Effect of Continuous White Noise of Different Intensities on Corti's Organ in Guinea Pigs

The Corti's organs of the guinea pigs were examined by scanning electron microscope either immediately or 1,3,7,15,or 30 days after the exposure to continuous white noise at different intensities of 125 dB SPL and 132 dB SPL for 1 hour.Swelling,fusion,collapse and even loss of OHC stereocilia were mainly observed in the third and forth turns of cochlea. There was a lesion length of 10mm of corti's organ in guinea pigs immediately after the exposure to white noise at 132 dB SPL,and 7 mm at 125 dB SPL.70% of OHC was damaged in the lesion length of 10 mm of Corti's Organ in guinea pigs immediately after the exposure to white noise at 132 dB SPL,and 50% of OHC in the lesion length of 7 mm at 125dB SPL.The lesion length of Corti's organ and the amount of OHC were increased with the intensity of white noise,and decreased with the survival intervals after the exposure.The slight damage to OHC stereocilia,such as swelling and fusion,could be recoverable subsequent to the exposure to white noise,but the moderate and severe damage,such as collapse and loss of stereocilia were unrecoverable.It seemed that the early stage(less than 15 days after the exposure to white noise at 132 dB SPL,and 7 days at 125 dB SPL)was essential for the affected OHC to recover from the damage.The relationship of the features of damage to hair cells with white noise was discussed.