title: Imaging of the cortical cytoskeleton of guinea pig outer hair cells using atomic force microscopy.
abstract: Mammalian outer hair cells (OHCs) are known to respond to acoustical stimulation with elongation and contraction of the cells' cylindrical soma in vivo, and this motility is related to both the protein motors distributed along the OHC plasma membrane and the cytoskeleton beneath it. Therefore, the cytoskeleton seems to play an important role in the motility of the OHC. Recently, an atomic force microscope (AFM) was used to investigate the OHC cytoskeleton under physiological conditions. However, details were not made clear in that study. In this study, the ultrastructure of the cytoskeleton of fixed OHCs of guinea pigs, which were extracted with Triton X-100, was investigated using the AFM. As a result, the cortical cytoskeleton, which is formed by discrete oriented domains, was imaged, and circumferential filaments and cross-links were observed within the domain. Morphological change of the cytoskeleton of the OHC induced by diamide treatment was then examined using the AFM, and reduction of cross-links was observed. The examination indicates that the cortical cytoskeleton comprises circumferential actin filaments and spectrin cross-links.
authors.affiliation: Department of Bioengineering and Robotics, Tohoku University, Sendai, 980-8579, Japan. wada@cc.mech.tohoku.ac.jp
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Wada
authors.forename: Kei
authors.initials: K
authors.lastname: Kimura
authors.forename: Takashi
authors.initials: T
authors.lastname: Gomi
authors.forename: Michiko
authors.initials: M
authors.lastname: Sugawara
authors.forename: Yukio
authors.initials: Y
authors.lastname: Katori
authors.forename: Seiji
authors.initials: S
authors.lastname: Kakehata
authors.forename: Katsuhisa
authors.initials: K
authors.lastname: Ikeda
authors.forename: Toshimitsu
authors.initials: T
authors.lastname: Kobayashi
mesh_terms: D008841:Actin Cytoskeleton / Q000187:drug effects / Q000648:ultrastructure; D000818:Animals; D003599:Cytoskeleton / Q000187:drug effects / Q000648:ultrastructure*; D003958:Diamide / Q000494:pharmacology; D006168:Guinea Pigs / Q000033:anatomy & histology*; D018072:Hair Cells, Auditory, Outer / Q000187:drug effects / Q000648:ultrastructure*; D018625:Microscopy, Atomic Force; D013439:Sulfhydryl Reagents / Q000494:pharmacology
chemical_list: D013439:Sulfhydryl Reagents; D003958:Diamide