Rat sciatic nerve crush surgery and tissue preparation

Sixty clean male Sprague-Dawley rats weighing 180–200 g and aged 2.5 months were provided by the Experimental Animal Center of Nantong University of China (animal license No. SCXK [Su] 2014-0001 and SYXK [Su] 2012-0031). All animal procedures were performed in accordance with the Institutional Animal Care Guidelines of Nantong University, China, and approved by the Administration Committee of Experimental Animals, Jiangsu Province, China.

Rats were equally randomized to five groups according to the time post injury (0, 1, 4, 7, and 14 days). All rats were anesthetized with mixed narcotics, including 85 mg/kg trichloroacetaldehyde monohydrate, 42 mg/kg magnesium sulfate, and 17 mg/kg sodium pentobarbital (Ruijie, Shanghai, China). The rats underwent an operation to crush the left sciatic nerve as previously described (Yi et al., 2015). Briefly, a skin incision was made on the lateral aspect of the mid-thigh of the left hind limb. The sciatic nerve was exposed and then crushed three times with forceps (54 N), for 10 seconds each. The muscle and skin were sutured. At 0, 1, 4, 7, and 14 days following nerve injury, sciatic nerve segments 5 mm in length at the injury site were harvested and then stored at −80°C.