title: Amyotrophic lateral sclerosis is a distal axonopathy: evidence in mice and man.
abstract: The SOD1 mutant mouse is the most widely used model of human amyotrophic lateral sclerosis (ALS). To determine where and when the pathological changes of motor neuron disease begins, we performed a comprehensive spatiotemporal analysis of disease progression in SOD1(G93A) mice. Quantitative pathological analysis was performed in the same mice at multiple ages at neuromuscular junctions (NMJ), ventral roots, and spinal cord. In addition, a patient with sporadic ALS who died unexpectedly was examined at autopsy. Mice became clinically weak at 80 days and died at 131 +/- 5 days. At 47 days, 40% of end-plates were denervated whereas there was no evidence of ventral root or cell body loss. At 80 days, 60% of ventral root axons were lost but there was no loss of motor neurons. Motor neuron loss was well underway by 100 days. Microglial and astrocytic activation around motor neurons was not identified until after the onset of distal axon degeneration. Autopsy of the ALS patient demonstrated denervation and reinnervation changes in muscle but normal appearing motor neurons. We conclude that in this widely studied animal model of human ALS, and in this single human case, motor neuron pathology begins at the distal axon and proceeds in a "dying back" pattern.
authors.affiliation: Department of Neurology, Emory University School of Medicine, Atlanta, GA 30322, USA.
authors.forename: Lindsey R
authors.initials: LR
authors.lastname: Fischer
authors.forename: Deborah G
authors.initials: DG
authors.lastname: Culver
authors.forename: Philip
authors.initials: P
authors.lastname: Tennant
authors.forename: Albert A
authors.initials: AA
authors.lastname: Davis
authors.forename: Minsheng
authors.initials: M
authors.lastname: Wang
authors.forename: Amilcar
authors.initials: A
authors.lastname: Castellano-Sanchez
authors.forename: Jaffar
authors.initials: J
authors.lastname: Khan
authors.forename: Meraida A
authors.initials: MA
authors.lastname: Polak
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Glass
mesh_terms: D000690:Amyotrophic Lateral Sclerosis / Q000201:enzymology / Q000235:genetics / Q000473:pathology*; D000818:Animals; D001369:Axons / Q000201:enzymology / Q000473:pathology*; D006801:Humans; D008297:Male; D051379:Mice; D008817:Mice, Mutant Strains; D008822:Mice, Transgenic; D013482:Superoxide Dismutase / Q000096:biosynthesis / Q000235:genetics; D000072105:Superoxide Dismutase-1; D013997:Time Factors
chemical_list: C000606290:SOD1 protein, human; C000606291:Sod1 protein, mouse; D013482:Superoxide Dismutase; D000072105:Superoxide Dismutase-1