title: Evaluation of Injured Axons Using Two-Photon Excited Fluorescence Microscopy after Spinal Cord Contusion Injury in YFP-H Line Mice.
abstract: Elucidation of the process of degeneration of injured axons is important for the development of therapeutic modules for the treatment of spinal cord injuries. The aim of this study was to establish a method for time-lapse observation of injured axons in living animals after spinal cord contusion injury. YFP (yellow fluorescent protein)-H transgenic mice, which we used in this study, express fluorescence in their nerve fibers. Contusion damage to the spinal cord at the 11th vertebra was performed by IH (Infinite Horizon) impactor, which applied a pressure of 50 kdyn. The damaged spinal cords were re-exposed during the observation period under anesthesia, and then observed by two-photon excited fluorescence microscopy, which can observe deep regions of tissues including spinal cord axons. No significant morphological change of injured axons was observed immediately after injury. Three days after injury, the number of axons decreased, and residual axons were fragmented. Seven days after injury, only fragments were present in the damaged tissue. No hind-limb movement was observed during the observation period after injury. Despite the immediate paresis of hind-limbs following the contusion injury, the morphological degeneration of injured axons was delayed. This method may help clarification of pathophysiology of axon degeneration and development of therapeutic modules for the treatment of spinal cord injury.
authors.affiliation: Department of Orthopaedic Surgery, Ehime University Graduate School of Medicine, Ehime 791-0295, Japan. hidekih@m.ehime-u.ac.jp.
authors.forename: Hideki
authors.initials: H
authors.lastname: Horiuchi
authors.affiliation: Department of Molecular Medicine for Pathogenesis, Ehime University Graduate School of Medicine, Ehime 791-0295, Japan. oshima-ehm@umin.ac.jp.|Translational Research Center, Ehime University Hospital, Ehime 791-0295, Japan. oshima-ehm@umin.ac.jp.|Division of Bio-imaging, Proteo-Science Center, Ehime University, Ehime 791-0295, Japan. oshima-ehm@umin.ac.jp.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Oshima
authors.affiliation: Department of Orthopaedic Surgery, Ehime University Graduate School of Medicine, Ehime 791-0295, Japan. ogata@m.ehime-u.ac.jp.
authors.forename: Tadanori
authors.initials: T
authors.lastname: Ogata
authors.affiliation: Department of Orthopaedic Surgery, Ehime University Graduate School of Medicine, Ehime 791-0295, Japan. morino@m.ehime-u.ac.jp.
authors.forename: Tadao
authors.initials: T
authors.lastname: Morino
authors.affiliation: Department of Anatomy and Embryology, Ehime University Graduate School of Medicine, Ehime 791-0295, Japan. matsuda@m.ehime-u.ac.jp.
authors.forename: Seiji
authors.initials: S
authors.lastname: Matsuda
authors.affiliation: Department of Orthopaedic Surgery, Ehime University Graduate School of Medicine, Ehime 791-0295, Japan. miura@m.ehime-u.ac.jp.
authors.forename: Hiromasa
authors.initials: H
authors.lastname: Miura
authors.affiliation: Department of Molecular Medicine for Pathogenesis, Ehime University Graduate School of Medicine, Ehime 791-0295, Japan. timamura-ind@umin.ac.jp.|Translational Research Center, Ehime University Hospital, Ehime 791-0295, Japan. timamura-ind@umin.ac.jp.|Division of Bio-imaging, Proteo-Science Center, Ehime University, Ehime 791-0295, Japan. timamura-ind@umin.ac.jp.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Imamura
mesh_terms: D000818:Animals; D001369:Axons / Q000378:metabolism* / Q000473:pathology; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D004195:Disease Models, Animal; D008164:Luminescent Proteins / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D008822:Mice, Transgenic; D008856:Microscopy, Fluorescence; D017785:Photons; D013116:Spinal Cord / Q000378:metabolism; D013119:Spinal Cord Injuries / Q000378:metabolism / Q000473:pathology*; D059008:Time-Lapse Imaging
chemical_list: D001426:Bacterial Proteins; D008164:Luminescent Proteins; C054562:yellow fluorescent protein, Bacteria
keywords: axon degeneration; multiphoton excitation microscope; spinal cord injury; transgenic mouse