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Changes in motor unit properties in SOD1 (G93A) rats
Author(s) -
Kryściak Katarzyna,
Grieb paweł,
Celichowski Jan
Publication year - 2014
Publication title -
muscle and nerve
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.025
H-Index - 145
eISSN - 1097-4598
pISSN - 0148-639X
DOI - 10.1002/mus.24196
Subject(s) - amyotrophic lateral sclerosis , motor unit , reinnervation , denervation , sod1 , medicine , motor neuron , superoxide dismutase , anatomy , endocrinology , biology , neuroscience , oxidative stress , disease
: In amyotrophic lateral sclerosis (ALS), progressive death of motor neurons results in denervation and reinnervation of muscles. It is not clear how ALS affects the properties of motor units (MUs). Methods : Properties of single MUs in the medial gastrocnemius (MG) muscle of rats bearing the human mutated superoxide dismutase gene type 1 ( SOD1 ) were determined at 3 stages: asymptomatic (ALS I); early symptomatic (ALS II); and terminal (ALS III). Results : In ALS II, higher proportions of FF (fast fatigable) and S (slow) MUs were observed, whereas in ALS III higher percentages of S and lower percentages of FF MUs were noted compared with controls. S motor neurons reinnervated fast muscle fibers, and those MUs gained some properties of fast MUs, including lower fatigue resistance, greater force generation, and higher action potential amplitudes. Conclusion : Changes in MU properties of SOD1 rats have progressive and multidirectional character and speed depending on the MU type. Muscle Nerve 50: 577–586, 2014