声损伤后鸡听觉上皮的修复和毛细胞再生──扫描电镜与图像分析研究

应用扫描电镜和图像分析方法对宽带噪声损伤后鸡基底乳头病变以及听觉毛细胞再生反应进行定量研究。观察了存活０、２、７、１５和３０天时平均毛细胞表面积，平均毛细胞密度，毛细胞／支持细胞面积比及基底乳头损伤范围等参数。结果显示，基底乳头病变范围为近端１０％至中段６０％。早期反应包括支持细胞扩张和毛细胞静纤毛变性及皮板表面积缩小。损伤后２天可见新生毛细胞，形态与胚胎期幼稚毛细胞相似。７～１５天毛细胞数目与表面积逐渐增加，基底乳头ｍｏｓａｉｃ构型基本恢复。静纤毛排列与极性至３０天时尚未完全恢复。损伤区仍有散在的残存毛细胞及分化早期的幼稚毛细胞。上述结果提示，再生毛细胞的前体存在于受损区局部并与支持细胞的活动有关。前体细胞的增殖至再生毛细胞出现的时间约为４８ｈ，但亦存在一定程度的非同步现象，损伤后７～１５天为细胞修复的主要时期。

RESTORATION OF AUDITORY EPITHELIA AND REGENERATION OF HAIR CELL OF CHICKS FOLLOWING ACOUSTIC TRAUMA-STUDY OF SEM AND IMAGE ANALYSIS

Using SEM and image analysis technique the pathological changes and regeneration process of the hair cell (HC) were investigated quantitatively in acoustic damaged inner ear ofthe chick. The parameters of average HC area, average HC density and ratio of cell areawere measured with the image processing system. The results indicated that the lesion arearanged from 10% to 60% segments of the basilar papilla (BP). The extension of supportingcell (SC) and degeneration of HC with the surface reduction were observed in the earlier recovery stage. Newly formed HC were found in the second day of post-injury which morphologically resembled those immature HC of the embryo. The density and surface of HC gradually increased and the mosaic pattern of the BP restored during the period of 7-15 days afternoise exposure. However the arrangement and orientation of stereociliary bundles of HC didnot recover completely until 30 days post-damage. There were still a few sporadic immatureHC in the lesion region. From the findings above, we can postulate that the precursors of theregenerated HC exist within the lesion region which is related to the action of SC. The interval for the precursor to transform into HC is about 48 hours and the important stage for cellular repair is within 7-15 days after insult. The development and orientation of stereociliary bundles possibly require a longer time.