Spicer S S, Thomopoulos G N, Schulte B A
Department of Pathology and Laboratory Medicine, Medical University of South Carolina, 165 Ashley Avenue, Charleston, SC 29425, USA.
Hear Res. 2000 May;143(1-2):147-61. doi: 10.1016/s0378-5955(00)00037-x.
Cells medial to the tunnel of Corti were examined to assess fine structural features relevant to their proposed role in cochlear K(+) homeostasis. A dense network of canaliculi referred to as canalicular reticulum (CR) resided in the foot body of inner pillar cells, where it bordered and could resorb ions released from inner radial and spiral nerves. Lateral interdental cells (IDCs) formed columns which connected the inner sulcus epithelium with the base of the tectorial membrane's (TM) middle zone. A spout-like neck in cells at the top of lateral IDC columns housed a dense concentration of CR which resembled that characteristic of ion transporting epithelia and appeared to be located here for transporting ions and fluid toward the TM. Clustered IDCs in the center of the limbus connected underlying limbal stroma with the TM's limbal zone and appeared capable of transporting ions from stroma to TM. Abundant CR in limbal stellate fibrocytes evidenced their capacity to transport ions and fluid, presumably from inner sulcus epithelium toward central IDCs. The most medial IDCs possibly function as the terminus of an ion cycling path from scala vestibuli to endolymph. Light fibrocytes situated between supralimbal fibrocytes and medial IDCs appeared to serve as a link in this pathway. The limbal zone of the TM overlying central IDCs consisted of three distinct regions which offered a structural basis for transformation of an amorphous matrix supplied by central IDCs into the protofibrils of the membrane's middle zone.
对柯蒂氏管内侧的细胞进行了检查,以评估与它们在耳蜗钾离子稳态中所提出的作用相关的精细结构特征。一种被称为小管网状结构(CR)的致密小管网络存在于内柱细胞的足部体部,它在此处与内放射状神经和螺旋神经释放的离子相邻并可重吸收这些离子。外侧齿间细胞(IDC)形成柱状结构,将内沟上皮与盖膜(TM)中间区的基部相连。外侧IDC柱状结构顶部细胞中的一个壶嘴状颈部含有密集的CR,这类似于离子转运上皮细胞的特征,似乎位于此处用于将离子和液体向TM运输。位于缘膜中心的聚集IDC将下方的缘膜基质与TM的缘膜区相连,似乎能够将离子从基质运输到TM。缘膜星状纤维细胞中丰富的CR证明了它们运输离子和液体的能力,推测是从内沟上皮向中央IDC运输。最内侧的IDC可能作为从前庭阶到内淋巴的离子循环路径的终点。位于缘膜上纤维细胞和内侧IDC之间的轻度纤维细胞似乎在这条途径中起到连接作用。覆盖中央IDC的TM缘膜区由三个不同区域组成,为中央IDC提供的无定形基质转化为膜中间区的原纤维提供了结构基础。