Harrison R V, Cullen J R, Takeno S, Mount R J
Department of Otolaryngology, Hospital for Sick Children, Toronto, Canada.
Scanning Microsc. 1996;10(3):889-94.
The developmental time scale of the cochlea varies from species to species. We investigate here the condition of the neonatal cochlea in the chinchilla, a species increasingly used in auditory research. We have examined the morphology of cochlear hair cells using scanning microscopy, and the development of auditory function during the first postnatal month by monitoring auditory brainstem evoked responses (ABR). We find that although there were some outer hair cell kinocilia present in middle and apical areas, the hair cells otherwise were mature at 24 hours after birth. Furthermore, cochlear auditory thresholds are adult-like at birth. However, whilst there was little change in ABR thresholds over one month, there is evidence of continued maturation of the central auditory system as shown by the shortening of the PI-P5 latency from 9.1 ms to 7.7 ms.
耳蜗的发育时间尺度因物种而异。我们在此研究毛丝鼠新生耳蜗的状况，毛丝鼠是一种在听觉研究中越来越常用的物种。我们使用扫描显微镜检查了耳蜗毛细胞的形态，并通过监测听觉脑干诱发电位（ABR）研究了出生后第一个月内听觉功能的发育情况。我们发现，虽然在中部和顶部区域存在一些外毛细胞动纤毛，但其他毛细胞在出生后24小时就已成熟。此外，耳蜗听觉阈值在出生时就与成年时相似。然而，虽然ABR阈值在一个月内变化不大，但有证据表明中枢听觉系统在持续成熟，表现为PI - P5潜伏期从9.1毫秒缩短至7.7毫秒。
