title: Noninvasive detection of brainstem and spinal cord axonal degeneration in an amyotrophic lateral sclerosis mouse model.
abstract: Degeneration of motor neurons and their associated axons is a hallmark of amyotrophic lateral sclerosis, but reliable noninvasive lesion detection is lacking. In vivo diffusion tensor imaging was performed to evaluate neurodegeneration in the brainstem and cervical spinal cord of wild-type and G93A-SOD1 transgenic mice, an animal model of amyotrophic lateral sclerosis. A statistically significant reduction in the apparent diffusion coefficient was observed in the motor nuclei VII and XII of G93A-SOD1 transgenic mice relative to wild-type mice. No significant difference in diffusion anisotropy was observed in dorsal white or gray matter in cervical and lumbar segments of the spinal cord. In contrast, statistically significant decreases in axial diffusivity (diffusivity parallel to the axis of the spinal cord) and apparent diffusion coefficient were found in the ventrolateral white matter of G93A-SOD1 mice in both the cervical and lumbar spinal cord. The reduction in axial diffusivity, suggestive of axonal injury, in the white matter of the spinal cord of G93A-SOD1 mice was verified by immunostaining with nonphosphorylated neurofilament. The present study demonstrates that in vivo diffusion tensor imaging-derived axial diffusivity may be used to accurately evaluate axonal degeneration in an animal model of amyotrophic lateral sclerosis.
authors.affiliation: Department of Radiology, Washington University, St. Louis, MO 63110, USA. jhkim@bmr.wustl.edu
authors.forename: Joong Hee
authors.initials: JH
authors.lastname: Kim
authors.forename: Tzy-Haw
authors.initials: TH
authors.lastname: Wu
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Budde
authors.forename: Jin-Moo
authors.initials: JM
authors.lastname: Lee
authors.forename: Sheng-Kwei
authors.initials: SK
authors.lastname: Song
mesh_terms: D000690:Amyotrophic Lateral Sclerosis / Q000150:complications* / Q000473:pathology*; D000818:Animals; D001369:Axons / Q000473:pathology*; D001933:Brain Stem / Q000473:pathology*; D056324:Diffusion Tensor Imaging / Q000379:methods*; D004195:Disease Models, Animal; D005260:Female; D051379:Mice; D008822:Mice, Transgenic; D009410:Nerve Degeneration / Q000150:complications* / Q000473:pathology*; D013116:Spinal Cord / Q000473:pathology*; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D013482:Superoxide Dismutase