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Updated: Feb 18, 2026
Facial Nerve Axotomy in Mice: A Model to Study Motoneuron Response to Injury
Published on: February 23, 2015
Impact of volumetric muscle loss injury on persistent motoneuron axotomy
Benjamin T Corona1, Kate E Flanagan1, Christian M Brininger1
1Extremity Trauma and Regenerative Medicine Task Area, United States Army Institute of Surgical Research, 3698 Chambers Pass, BHT1, Fort Sam Houston, Texas, 78234, USA.
Introduction:
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.
