2.2 MCAO model
According to the modified Zea Longa’s method (Longa et al., 1989), the animal model of right Middle cerebral artery occlusion (MCAO) was made. In SD rats, 3% pentobarbital sodium (0.2 ml/100g) was injected peritoneally, the neck skin was cut open, the right common carotid artery (CCA), the external carotid artery (ECA) and the internal carotid artery (ICA) were exposed, a nylon thread was inserted into the stump of ECA along the artery bifurcation to the middle cerebral artery, and the right middle cerebral artery was blocked to establish a focal cerebral ischemia model in the right cerebral hemisphere. After 60 min, the nylon thread was gently pulled out to achieve reperfusion, and the body temperature was maintained until awake (37±0.5°C).