Shiel M J, Cotanche D A
Department of Anatomy, Boston University School of Medicine, Massachusetts 02118.
Hear Res. 1990 Aug 1;47(1-2):147-57. doi: 10.1016/0378-5955(90)90172-l.
The development of the tectorial membrane in the embryonic chick cochlea was studied using scanning electron microscopy. Chick embryos ranged in age from embryonic day 7 (E7) to post-hatching day 15. Our studies revealed that a fine filamentous matrix arose on the apical surface of the basilar papilla at approximately E7. This matrix was secreted by the supporting cells which encircled the hair cells. By E9, the early matrix had increased in volume but remained filamentous in structure, except at the inferior edge of the basilar papilla where it was condensed into a layer of laterally-oriented columns. At E9 the TM exhibited an additional layer of matrix, called the amorphous component. It appeared to originate from the homogene cell population, and attached to the early columnar matrix at the inferior edge of the basilar papilla. The two components of the TM were separated by a longitudinal ridge, called the 'track', which marked the inferior edge of the amorphous component. As the cochlea developed, the basilar papilla increased in width, the columnar component elongated and the track appeared to recede. These morphological findings point to separate developmental origins for the two components of the tectorial membrane.
利用扫描电子显微镜研究了胚胎期小鸡耳蜗盖膜的发育情况。小鸡胚胎的年龄范围从胚胎第7天（E7）到孵化后第15天。我们的研究表明，在大约E7时，基底乳头的顶端表面出现了一种细丝状基质。这种基质由环绕毛细胞的支持细胞分泌。到E9时，早期基质体积增加，但结构仍为丝状，除了在基底乳头的下缘，在那里它浓缩成一层横向排列的柱状结构。在E9时，盖膜表现出另一层基质，称为无定形成分。它似乎起源于同质细胞群，并附着在基底乳头下缘的早期柱状基质上。盖膜的两个成分被一条纵向嵴分开，这条嵴称为“轨迹”，它标志着无定形成分的下缘。随着耳蜗的发育，基底乳头变宽，柱状成分伸长，轨迹似乎后退。这些形态学发现表明盖膜的两个成分有不同的发育起源。
