TA and gastrocnemius muscles were sectioned on a cryostat (10 μM thick) and hematoxylin and eosin-phloxine staining was performed. These sections were used to count the percentage of fibers with central nuclei using the methods previously described [1 (link)]. Additional TA muscle sections from 3 and 7 day cohorts were assessed for Mac-1 expression, a marker for leukocytes. To do this, sections were fixed in acetone, blocked using a Streptavidin/Biotin Blocking Kit (SP-2002, Vector Laboratories, Burlingame, CA), incubated in rat anti-mouse CD11b primary antibody (550282, BD Biosciences, San Jose, CA) or IgG2b (559478, BD Biosciences) for controls, followed by a biotin goat anti-rat Ig secondary antibody (559286, BD Biosciences). Antigen-antibody interactions were visualized using DAB (550880, BD Biosciences). For each slide, ten digital images were acquired at 40X magnification (Leica DM2000 and QImaging Micropublisher RTV 5.0). A single, blinded investigator assessed the % area of positive staining per image using thresholding (Image J software, National Institutes of Health, Bethesda, MD). The average % of muscles’ cross-sectional area stained positive from the 10 images per muscle section was calculated and used for statistical analyses.