Beyer L A, Odeh H, Probst F J, Lambert E H, Dolan D F, Camper S A, Kohrman D C, Raphael Y
The Department of Otolaryngology, Kresge Hearing Research Institute, School of Medicine, The University of Michigan, USA.
J Neurocytol. 2000 Apr;29(4):227-40. doi: 10.1023/a:1026515619443.
The shaker 2 (sh2) and pirouette (pi) mouse mutants display severe inner ear dysfunction that involves both auditory and vestibular manifestation. Pathology of the stereocilia of hair cells has been found in both mutants. This study was designed to further our knowledge of the pathological characteristics of the inner ear sensory epithelia in both the sh2 and pi strains. Measurements of auditory brainstem responses indicated that both mutants were profoundly deaf. The morphological assays were specifically designed to characterize a pathological actin bundle that is found in both the inner hair cells and the vestibular hair cells in all five vestibular organs in these two mutants. Using light microscope analysis of phalloidin-stained specimens, these actin bundles could first be detected on postnatal day 3. As the cochleae matured, each inner hair cell and type I vestibular hair cell contained a bundle that spans from the region of the cuticular plate to the basal end of the cell, then extends along with cytoplasm and membrane, towards the basement membrane. Abnormal contact with the basement membrane was found in vestibular hair cells. Based on the shape of the cellular extension and the actin bundle that supports it, we propose to name these extensions "cytocauds." The data suggest that the cytocauds in type I vestibular hair cells and inner hair cells are associated with a failure to differentiate and detach from the basement membrane.
摇筛器2（sh2）和芭蕾舞旋转（pi）小鼠突变体表现出严重的内耳功能障碍，涉及听觉和前庭表现。在这两种突变体中均发现了毛细胞静纤毛的病理学变化。本研究旨在进一步了解sh2和pi品系内耳感觉上皮的病理特征。听觉脑干反应测量表明，两种突变体均严重失聪。形态学分析专门用于表征在这两种突变体的所有五个前庭器官的内毛细胞和前庭毛细胞中均发现的病理性肌动蛋白束。通过对鬼笔环肽染色标本进行光学显微镜分析，这些肌动蛋白束在出生后第3天首次被检测到。随着耳蜗成熟，每个内毛细胞和I型前庭毛细胞都包含一束肌动蛋白束，该束从表皮板区域延伸到细胞的基部末端，然后随着细胞质和细胞膜一起延伸，朝向基底膜。在前庭毛细胞中发现了与基底膜的异常接触。根据细胞延伸部分及其所支撑的肌动蛋白束的形状，我们建议将这些延伸部分命名为“细胞尾”。数据表明，I型前庭毛细胞和内毛细胞中的细胞尾与无法从基底膜分化和脱离有关。
