大鼠耳蜗大上皮嵴的形态学演变

Morphological Change of the Greater Epithelial Ridge in Rat Cochleae

目的 观察不同胚胎期的大鼠和新生大鼠耳蜗大上皮嵴形态上的变化。方法 选取胚胎期 14、16、18、2 0天和出生后当天、2、5、7、10、14天等 10个时间段的大鼠耳蜗 ,分别进行冰冻切片和HE染色。结果 毛细胞的分化成熟是从底回向顶回进行 ,顶回较底回有 1～ 2天的延迟。大上皮嵴结构重排、细胞减少从腔侧开始 ,出生后 2周左右当毛细胞分化成熟时消失。结论 胚胎期 14天前后是大上皮嵴形态演变的关键时期。大上皮嵴是耳蜗形态不成熟的标志之一。

Objective To observe morphological change in the greater epithelial ridge (GER) of rat cochlea at different stages.Methods Rat cochlea in embryonic days 14,16,18,20 and postnatal days 0,2,5,7,10,14 were selected.7 μm sections of the preparations were cut with a cryostat. The sections were processed for Hematoxylin and Eosin staining. Results Differentiating and maturing of hair cells were developed from basal turn to apical turn. The latter had a delay of 1-2 days. The rearrangement of cytoarchitecture and decrease in cells started from the luminal surface of GER. As hair cells matured at P14, the GER disappeared.Conclusion Embryonic day 14 is the key stage of morphological change in the greater epithelial redge.The greater epithelial ridge can be regarded as a morphological symbol of cochlea immature.