期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2012
卷号：109
期号：12
页码：4473-4478
DOI：10.1073/pnas.1101003109
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The striated organelle (SO), a cytoskeletal structure located in the apical region of cochlear and vestibular hair cells, consists of alternating, cross-linked, thick and thin filamentous bundles. In the vestibular periphery, the SO is well developed in both type I and type II hair cells. We studied the 3D structure of the SO with intermediate-voltage electron microscopy and electron microscope tomography. We also used antibodies to -2 spectrin, one protein component, to trace development of the SO in vestibular hair cells over the first postnatal week. In type I cells, the SO forms an inverted open-ended cone attached to the cell membrane along both its upper and lower circumferences and separated from the cuticular plate by a dense cluster of exceptionally large mitochondria. In addition to contacts with the membrane and adjacent mitochondria, the SO is connected both directly and indirectly, via microtubules, to some stereociliary rootlets. The overall architecture of the apical region in type I hair cells--a striated structure restricting a cluster of large mitochondria between its filaments, the cuticular plate, and plasma membrane--suggests that the SO might serve two functions: to maintain hair-cell shape and to alter transduction by changing the geometry and mechanical properties of hair bundles.
