title: Regionally varying F-actin network in the apical cytoplasm of ependymocytes.
abstract: F-actin participates in morphogenetic cell-shape changes and helps maintain cellular integrity. Actin-like proteins have been detected in the ependymocytes of the cerebral ventricles, but the distribution of F-actin along the ventricular system has not been studied. We observed a highly ordered and regionally varying F-actin network in the apical cytoplasm of the ependyma in the ventricular system of rats using fluorescein isothiocyanate-conjugated phalloidin. Dense F-actin bundles spanned the entire circumference of the central canal of the spinal cord and formed a characteristic ring-like network in the apical region. The apical F-actin layer was widest in the lower cervical canal, and narrower in the upper thoracic canal. However, in the lower part of the filum terminale, the apical F-actin bundles became sparser and even disappeared. The apical F-actin layer differs significantly between the ventral and dorsal aspects above the medulla oblongata. This suggests that the regionally varying distribution of F-actin reflects the diverse local demands of the ependymocytes for cellular integrity and adhesive activity against external forces.
authors.affiliation: Laboratory for Neural Architecture, RIKEN Brain Science Institute, Hirosawa 2-1, Wako-Shi, Saitama 351-0198, Japan. ldlyc@brain.riken.jp
authors.forename: Yan-Chao
authors.initials: YC
authors.lastname: Li
authors.forename: Wan-Zhu
authors.initials: WZ
authors.lastname: Bai
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Hashikawa
mesh_terms: D000199:Actins / Q000378:metabolism*; D000818:Animals; D002552:Cerebral Ventricles / Q000033:anatomy & histology; D003593:Cytoplasm / Q000378:metabolism*; D004805:Ependyma / Q000166:cytology*; D005455:Fluorescent Antibody Technique / Q000379:methods; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D014746:Vimentin / Q000378:metabolism
chemical_list: D000199:Actins; D014746:Vimentin