Zine A, Romand R
Laboratoire de Neurobiologie, Université Blaise Pascal-Clermont II, Aubière, France.
Brain Res. 1996 May 20;721(1-2):49-58. doi: 10.1016/0006-8993(96)00147-3.
Fetal and postnatal ontogenesis of the rat cochlea, from the 16th gestational day (16DG) until 3 months post partum, were studied using scanning electron microscopy with emphasis on the stereocilia during the earliest stages of development. The epithelium of the cochlear duct in 16DG rat consisted of plygonal cells topped with numerous microvilli and one central kinocilium, which form the so-called Kölliker's organ. Inner hair cells (IHCs) appeared at 18DG in the basal cochlea. They were characterized by tufts of cilia of the same height and with a kinocilium. The first outer hair cells (OHCs) can be seen at 20DG. The earliest stages of ciliary differentiation, at 18DG for IHCs and 20DG for OHCs, were similar on both types of cells and were characterized by the presence of round bundles of cilia arising from the surrounding microvilli. A three-dimensional V-shaped organization for OHCs and the linear arrangement for IHCs appeared by the end of the first postnatal week, accompanied by the disappearance of transient cilia on the modiolar side of the hair cell and the kinocilium on the external side. The apical pole of OHCs reached adult-like morphology before that of IHCs. Various links between stereocilia were detected already at birth. Morphometric analysis showed that auditory cells from the base of the cochlea reached adult size by the end of the first postnatal week while those from the apex increased their size later. A review of the literature including comparative observations across species on the ontogenesis of the stereocilia shows that hair cells of the stato-acoustic system may present the same early ontogenesis.
利用扫描电子显微镜研究了大鼠耳蜗从妊娠第16天（16DG）到产后3个月的胎儿期和产后发育过程，重点关注发育早期的静纤毛。16DG大鼠耳蜗管的上皮由多边形细胞组成，顶部有许多微绒毛和一根中央动纤毛，形成所谓的科蒂氏器。内毛细胞（IHCs）在18DG时出现在耳蜗基部。它们的特征是有一簇高度相同的纤毛且有一根动纤毛。最早的外毛细胞（OHCs）在20DG时可见。IHCs在18DG、OHCs在20DG时的纤毛分化早期阶段，在两种类型的细胞中相似，其特征是从周围微绒毛产生圆形的纤毛束。出生后第一周结束时，OHCs呈现三维V形排列，IHCs呈现线性排列，同时毛细胞蜗轴侧的过渡性纤毛和外侧的动纤毛消失。OHCs的顶端极在IHCs之前达到成年样形态。出生时就已检测到静纤毛之间的各种连接。形态计量分析表明，耳蜗基部的听觉细胞在出生后第一周结束时达到成年大小，而顶端的听觉细胞则在之后增大其大小。对包括跨物种关于静纤毛发育的比较观察在内的文献综述表明， stato - 听觉系统的毛细胞可能呈现相同的早期发育过程。
