Pollice P A, Brownell W E
Department of Otolaryngology-HNS, Johns Hopkins University School of Medicine, Baltimore, MD 21205-2196.
Hear Res. 1993 Nov;70(2):187-96. doi: 10.1016/0378-5955(93)90157-v.
We examined the properties of outer hair cell (OHC) lateral wall membranes by application of 2 fluorescent membrane probes. The markers, C6-NBD-Ceramide and DiOC6, have been used in other cell types to label Golgi apparatus and endoplasmic reticulum, respectively. In living isolated OHCs NBD-Ceramide demonstrated uninterrupted fluorescence along the OHC lateral wall, while DiOC6 labeling proved punctate and notably less uniform in this region. In aldehyde-fixed isolated OHCs both probes exhibited distinct, continuous lateral wall fluorescence. Fixed preparations of the organ of Corti labeled with each probe demonstrated diffuse fluorescence throughout the inner hair cell cytoplasm unlike the uniform, circumferential lateral wall fluorescence seen in OHCs. OHCs exposed to salicylate following NBD-Ceramide labeling displayed patchy, less distinct labeling along the OHC lateral wall. The thickness of lateral wall fluorescence in salicylate exposed cells was 49% greater than control OHCs. We interpreted the salicylate induced change in lateral wall labeling as a fluorescent representation of previously described ultrastructural dilatation and vesiculation of the subsurface cisternae. The distribution of these 2 fluorescent probes along OHC lateral wall membranes suggests that the OHC's subsurface cisternae are neither Golgi nor ER, but share characteristics of both.
我们通过应用两种荧光膜探针研究了外毛细胞（OHC）侧壁膜的特性。标记物C6-NBD-神经酰胺和DiOC6已分别用于其他细胞类型中标记高尔基体和内质网。在活的分离的OHC中，NBD-神经酰胺沿OHC侧壁显示出不间断的荧光，而DiOC6标记在此区域呈点状且明显不那么均匀。在醛固定的分离的OHC中，两种探针均显示出明显的、连续的侧壁荧光。用每种探针标记的柯蒂氏器固定制剂在整个内毛细胞细胞质中显示出弥漫性荧光，这与OHC中看到的均匀的、周向的侧壁荧光不同。在NBD-神经酰胺标记后暴露于水杨酸盐的OHC沿OHC侧壁显示出斑驳的、不太明显的标记。水杨酸盐暴露细胞中侧壁荧光的厚度比对照OHC大49%。我们将水杨酸盐诱导的侧壁标记变化解释为先前描述的表面下池超微结构扩张和囊泡化的荧光表现。这两种荧光探针沿OHC侧壁膜的分布表明，OHC的表面下池既不是高尔基体也不是内质网，但兼具两者的特征。
