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Impact of volumetric muscle loss injury on persistent motoneuron axotomy
Author(s) -
Corona Benjamin T.,
Flanagan Kate E.,
Brininger Christian M.,
Goldman Stephen M.,
Call Jarrod A.,
Greising Sarah M.
Publication year - 2018
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.26016
Subject(s) - axotomy , motor unit , denervation , medicine , isometric exercise , skeletal muscle , anatomy , neuroscience , biology , central nervous system
Volumetric muscle loss (VML) occurs following significant traumatic injury or surgical removal of skeletal muscle, resulting in nonrecoverable loss of tissue and long‐term dysfunction. Perhaps less recognized is that VML injuries inherently disrupt the neuromuscular unit, resulting in fiber denervation and presumptive motor unit rearrangement, expansion, and/or loss. To characterize neural dysfunction we quantified motoneuron axotomy, in efforts to understand how this relates to the temporal coordination of neuromuscular and morphological alterations due to injury. Methods In an established rat tibialis anterior (TA) VML injury model, we examined the motoneuron, skeletal muscle, and maximal isometric torque at 3, 7, 14, and 21 days postinjury. Results Significant axotomy of 57–79% of all TA muscle motoneurons was observed through 21 days postinjury, which was coupled with a 45–90% TA maximal torque deficit. Discussion A ∼20% partial ablation of the TA muscle causes disproportionate damage across the motor unit acutely postinjury. Muscle Nerve 57 : 799–807, 2018