title: Progressive motor unit loss in the G93A mouse model of amyotrophic lateral sclerosis is unaffected by gender.
abstract: We examined whether there are gender differences in the progressive loss of functional motor units in SOD1(G93A) transgenic mice. Isometric muscle and motor unit twitch contractions were recorded in fast- and slow-twitch muscles in response to stimulation of the sciatic nerve. Using a modified motor unit number estimation technique (ITS-MUNE), we found that motor unit numbers declined rapidly from 40 to 90 days of age during the asymptomatic phase of ALS in fast- but not slow-twitch hindlimb muscles of both male and female mice. There was a corresponding decline in twitch and tetanic contractile forces of the fast-twitch muscles. Gender did not affect the progressive loss of motor units and associated decline in force production. We conclude that gender does not alter progressive, muscle-specific motor unit loss in ALS, even though gender does influence disease onset.
authors.affiliation: Centre for Neuroscience, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: J
authors.initials: J
authors.lastname: Hegedus
authors.forename: C T
authors.initials: CT
authors.lastname: Putman
authors.forename: T
authors.initials: T
authors.lastname: Gordon
mesh_terms: D000367:Age Factors; D000690:Amyotrophic Lateral Sclerosis / Q000235:genetics* / Q000473:pathology / Q000503:physiopathology*; D000818:Animals; D004195:Disease Models, Animal; D018450:Disease Progression; D004576:Electromyography / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D009046:Motor Neurons / Q000502:physiology*; D009119:Muscle Contraction / Q000502:physiology; D018482:Muscle, Skeletal / Q000473:pathology* / Q000503:physiopathology; D009929:Organ Size / Q000502:physiology; D012737:Sex Factors; D013482:Superoxide Dismutase / Q000235:genetics*
chemical_list: C109415:SOD1 G93A protein; D013482:Superoxide Dismutase