3.2. Muscle Denervation Model

One hindlimb of mice was denervated by the surgical removal of at least 5 mm of sciatic nerve under anesthesia with the inhalational application of a mixture gas of isoflurane and oxygen, as described previously [16]. Sham control mice were operated in the same way without sciatic nerve removal. The surgical staples were used to close wounds. After the denervation surgery, mice were exposed to As₂O₃ in drinking water for 4 weeks. Muscle strength was assessed after As₂O₃ exposure. At the end of experiments, anesthetized animals were humanely sacrificed. Skeletal muscles (soleus, tibialis anterior (TA), and gastrocnemius (GAS) muscle) were harvested and weighed. Portions of these muscles were frozen at −80 ℃. Other portions were fixed over-night in 4% paraformaldehyde at room temperature for following histological analysis.