Guo Weiwei, Yi Haijin, Yan Zhang, Ren Lili, Chen Lei, Zhao Li Dong, Ning Yu, He David Z Z, Yang Shi-Ming
Department of Otolaryngology-Head and Neck Surgery, Institute of Otolaryngology of PLA, Chinese PLA General Hospital, No. 28, FuXing Road, Haidian District, Beijing 100853, China.
State Key Laboratory for Agro-Biotechnology, China Agricultural University, No. 17, Tsinghua East Road, Haidian District, Beijing 100083, China.
Reprod Fertil Dev. 2017 Mar;29(3):585-593. doi: 10.1071/RD15183.
The purpose of this study was to examine the morphological and functional development of the lateral wall of the scala media of the cochlea in miniature pigs; light and transmission electron microscopy and electrophysiology were used for this purpose. We showed that the lateral wall of the scala media of the cochlea appears at embryonic Day 21 (E21) when the cochlear duct begins to form. From E28 to E49, the lateral wall can be distinguished according to its position along the cochlea. At E56, cells in the lateral wall begin to differentiate into three different types. At E70, three cell types, marginal, intermediate and basal, can be clearly distinguished. At E91, the stria vascularis is adult-like and the organ of Corti is also morphologically mature. The average endocochlear potential measured from the second turn of the cochlea (at E98, postnatal Day 1 (P1), P13 and P30) was 71.4±2.5 (n=7), 78.8±1.5 (n=10), 77.3±2.3 (n=10) and 78.0±2.1 mV (n=10), respectively. Our results suggest that in miniature pigs the stria vascularis develops during the embryonic period, concurrent with maturation of the organ of Corti. The magnitude of the endocochlear potential reached its mature level when the stria vascularis was morphologically adult-like at E98. These findings provide a morphological and functional basis for future animal studies using the miniature pig model concerning the pathogenesis of various inner-ear diseases.
本研究的目的是研究小型猪耳蜗中阶外侧壁的形态和功能发育；为此采用了光镜、透射电镜和电生理学方法。我们发现，当耳蜗管开始形成时，耳蜗中阶外侧壁在胚胎第21天（E21）出现。从E28到E49，外侧壁可根据其在耳蜗中的位置加以区分。在E56时，外侧壁细胞开始分化为三种不同类型。在E70时，可清晰区分出边缘细胞、中间细胞和基底细胞三种细胞类型。在E91时，血管纹已呈成年样，柯蒂氏器在形态上也已成熟。从耳蜗第二转测量的内淋巴电位平均值（在E98、出生后第1天（P1）、P13和P30）分别为71.4±2.5（n = 7）、78.8±1.5（n = 10）、77.3±2.3（n = 10）和78.0±2.1 mV（n = 10）。我们的结果表明，在小型猪中，血管纹在胚胎期发育，与柯蒂氏器的成熟同时发生。当血管纹在E98时在形态上呈成年样时，内淋巴电位达到其成熟水平。这些发现为未来使用小型猪模型进行的关于各种内耳疾病发病机制的动物研究提供了形态和功能基础。
