Denervation (DEN) decreases hindlimb muscle mass and cross-sectional area (CSA). A: tibialis anterior (TA) muscle mass corrected for body mass (BM, n = 5–7 per time point). B: TA wet weight corrected for dry weight (n = 3 per time point). C: extensor digitorum longus (EDL) muscle mass corrected for body mass (n = 4 per time point). D: succinate dehydrogenase staining of sham-operated and denervated EDL muscles at 24 h, 3 days, and 7 days of denervation. E: fiber size distributions from sham-operated, 3-day-denervated, and 7-day-denervated EDL muscles. CSA data for sham-operated hindlimbs are pooled results of all sham-operated muscles analyzed (n = 4 per time point). *P < 0.05 vs. sham at the same time point. Values are means ± SE.