2.5. Chronic Constriction Injury of the Sciatic Nerve Model

After 28 days of chronic unpredictable mild stress, chronic constriction injury of the sciatic nerve model was made in the latter 3 groups of rats. Before the operation, the rats were anesthetized with isoflurane gas and placed on the operating table of the animals in the prone position. Remove the hair in the middle of the left thigh of rats, cut open the skin in the outer margin of the thigh femur, blunt and separate the muscles, and expose the sciatic nerve trunk. Wrap the 4-0 chrome gut around the middle of the sciatic nerve stem and tie a knot. Tighten the knot at a constant speed until it is just on either side of the nerve stem, creating a slight compression. Tie the second knot carefully to avoid any effect on the tightness of the first knot. In this way, the sciatic nerve trunk is evenly three knots with an interval of about 1 mm [17]. The skin wound was nailed with metal nails to prevent rats from gnawing. Each operator is fixed to ensure that the ligation force is comparable [18].