不同日龄小鼠听性脑干反应和静纤毛形态的发育特性

Characteristics of auditory brainstem responses and the development of the bundles of inner and outer hair cell of newborn mice

目的:探讨不同日龄昆明种小鼠听功能和内耳毛细胞的发育状况。方法:①测试不同日龄小鼠听性脑干反应(ABR),比较阈值、I波潜伏期;②对不同日龄小鼠的耳蜗Corti器内外毛细胞静纤毛束的发育进行扫描电镜观察。结果:稳定的ABR波型出现于生后17d龄之小鼠,随着小鼠日龄增加,反应阈越来越低,I波潜伏期越来越短;17d左右,小鼠内外毛细胞静纤毛发育成熟。结论:小鼠内耳毛细胞静纤毛的发育与ABR发育具有同步性,显示了功能成熟和结构成熟的一致性。

Objective:To investigate the characteristics of the ABR and discuss the development of the bundles of inner and outer hair cell. Method:Testing the ABR of newborn mice, the response threshold of ABR, latency of wave I were examined. Using scanning electron microscopy ?the development of the bundles of inner and outer hair cell of postnatal mice were studied. Result; (1)The average response threshold of ABR was (57. 5 + 2) dB of 15-day-old mice. The average response threshold of ABR was (37. 5 + 1) dB of 17-day-old, 21-day-old and 28-day-old mice. There was no difference in wave form. (2)The latencies of wave I of ABR differed significantly ( P <0. 05) in 15-day-old mice and 17-day-old mice,21-day-old mice and 28-day-old mice. The latencies of wave I of ABR didn 't differ significantly ( P >0. 05) in 17-day-old mice and 21-day-old mice and 28-day-old mice. (3)The development of the bundles is interpreted as a five-step process. Conclusion;The stable ABR appeared at the mice of 17 days. The response threshold goes down gradually. The latency of wave I becomes shorter and shorter. The bundles of inner and outer hair cell of newborn 17-day-old mice get maturity.