title: The relationship between Bayesian motor unit number estimation and histological measurements of motor neurons in wild-type and SOD1(G93A) mice.
abstract: OBJECTIVE
  To assess the relationship between Bayesian MUNE and histological motor neuron counts in wild-type mice and in an animal model of ALS.
  
  
  METHODS
  We performed Bayesian MUNE paired with histological counts of motor neurons in the lumbar spinal cord of wild-type mice and transgenic SOD1(G93A) mice that show progressive weakness over time. We evaluated the number of acetylcholine endplates that were innervated by a presynaptic nerve.
  
  
  RESULTS
  In wild-type mice, the motor unit number in the gastrocnemius muscle estimated by Bayesian MUNE was approximately half the number of motor neurons in the region of the spinal cord that contains the cell bodies of the motor neurons supplying the hindlimb crural flexor muscles. In SOD1(G93A) mice, motor neuron numbers declined over time. This was associated with motor endplate denervation at the end-stage of disease.
  
  
  CONCLUSIONS
  The number of motor neurons in the spinal cord of wild-type mice is proportional to the number of motor units estimated by Bayesian MUNE. In SOD1(G93A) mice, there is a lower number of estimated motor units compared to the number of spinal cord motor neurons at the end-stage of disease, and this is associated with disruption of the neuromuscular junction.
  
  
  CONCLUSIONS
  Our finding that the Bayesian MUNE method gives estimates of motor unit numbers that are proportional to the numbers of motor neurons in the spinal cord supports the clinical use of Bayesian MUNE in monitoring motor unit loss in ALS patients.
authors.affiliation: University of Queensland Centre for Clinical Research, University of Queensland, Australia.
authors.forename: S T
authors.initials: ST
authors.lastname: Ngo
authors.forename: F
authors.initials: F
authors.lastname: Baumann
authors.forename: P G
authors.initials: PG
authors.lastname: Ridall
authors.forename: A N
authors.initials: AN
authors.lastname: Pettitt
authors.forename: R D
authors.initials: RD
authors.lastname: Henderson
authors.forename: M C
authors.initials: MC
authors.lastname: Bellingham
authors.forename: P A
authors.initials: PA
authors.lastname: McCombe
mesh_terms: D000690:Amyotrophic Lateral Sclerosis / Q000473:pathology*; D000818:Animals; D001499:Bayes Theorem; D004195:Disease Models, Animal; D008159:Lumbar Vertebrae; D051379:Mice; D008822:Mice, Transgenic; D008962:Models, Theoretical; D009046:Motor Neurons / Q000473:pathology*; D009469:Neuromuscular Junction / Q000473:pathology; D013116:Spinal Cord / Q000473:pathology*; D013482:Superoxide Dismutase / Q000235:genetics*; D000072105:Superoxide Dismutase-1
chemical_list: C000606291:Sod1 protein, mouse; D013482:Superoxide Dismutase; D000072105:Superoxide Dismutase-1