POST-EMBRYONIC PRODUCTION AND AGING OF INNER-EAR HAIR-CELLS IN SHARKS
POST-EMBRYONIC PRODUCTION AND AGING OF INNER-EAR HAIR-CELLS IN SHARKS
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DOI：
10.1002/cne.902010406
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发表时间：
1981-01-01
影响因子：
2.5
通讯作者：
CORWIN, JT
中科院分区：
文献类型：
--
作者：
CORWIN, JT
在许多动物中，内耳的感觉毛细胞在单个上皮细胞内的超微结构是不同的。这种变异假设与单个细胞的功能和年龄有关。在幼年和成年鲨鱼的黄斑部感觉上皮细胞中，研究了毛细胞数量与生长相关的变化。扫描电子显微镜显示，在成虫S黄斑的20万个毛细胞中，有80%是在胚胎后产生的。~3H-胸腺嘧啶核苷放射自显影和毛细胞的组织学描述表明，在上皮细胞边缘的生长区产生了新的感觉细胞。这些区域的毛细胞具有小细胞体、小而异质的纤毛复合体，并与少量特别细的神经末梢相联系。它们的细胞学特征和稀疏的神经支配与每个上皮中数量更多的中心细胞的特征形成对比，但似乎与已发表的胚胎发育毛细胞的描述相似。在鲨鱼中，感觉上皮生长前沿的生发区似乎一直持续到成年。根据这一证据重新解读发表的报告表明，在其他羊水动物中可能会出现这种毛细胞种群的增长，潜在的生长区可能会持续存在于羊水动物的耳朵中。
In many animals the sensory hair cells of the inner ear are ultrastructurally variable within individual epithelia. This variation was hypothetically related to both the function and the age of the individual cells. Growth-related changes in hair cell populations were examined in the macula neglecta sensory epithelia of juvenile and adult sharks. Scanning electron microscopy demonstrated that > 80% of the 200,000 hair cells in the adult''s macula neglecta are produced postembryonically. 3H-thymidine autoradiography and histological descriptions of the hair cells in this sound detector indicate that new sensory cells are produced in growth zones at the edges of the epithelia. The hair cells in those zones have small cell bodies, small and heterogeneous cilia complexes, and associations with small numbers of particularly thin nerve terminals. Their cytological features and their sparse innervation contrast with the features of the more numerous central cells in each epithelium, but appear to resemble the published descriptions of embryonically developing hair cells. A germinal zone at the leading edge of sensory epithelium growth appears to persist into adult life in sharks. Published reports reinterpreted in light of this evidence suggest that such hair cell population growth may be expected in other anamniotes and that latent growth zones might persist in the ears of amniotes.