Rat Model for Cerebral Ischemia (CI)

1. 15% chloral hydrate to anesthetize rats, neck skin preparation, disinfection, insert the anus temperature probe, maintain the temperature within 37±0.5℃.
2. Incision of the middle of the neck, exposure the right common carotid artery, internal carotid artery and external carotid artery. Using 6-0 silk (at 4mm distance from the common carotid artery bifurcation ) to ligate the external carotid artery at the far end of the heart, pierces another 6-0 silk in the external carotid artery , and hit a slipknot near the bifurcation of the common carotid artery.
3. Use arterial clamps to clamp the common carotid artery. Make a small cut on the external carotid artery (3mm distance from bifurcation of common carotid artery ), a root tip treated 0.33 mm diameter nylon line from the cut insertion into the internal carotid artery, and inward into the middle cerebral artery, nylon line insertion depth distance carotid artery bifurcation about 16±1mm.
4. Ischemia 90 mins and pull the suture, a 6-0 silk ligates artery proximal, 3-0 silk suture wounds on the neck, povidone iodine disinfection wound, rat put in a heating pad, and feed on constant temperature raising box after rats awake.
5. 24hrs after operation, neurological function score was evaluated, and then the rats were injected intraperitoneally with 15% hydrate of chlorine aldehyde, and the brain was stained with TTC and pathological staining.

1.Neurological dysfunction score
Longa and Bederson's 5 point systems,make a score on rats waked from anaesthesia 24 hours later.
0 points: no nerve injury symptoms
1 points can not fully extend the forepaw
2 points: to the opposite side
3 points: to the side dump
4 points: can not walk spontaneously, loss of consciousness
2.TTC staining
Take the brain and store at -20℃,1% TTC (W/V), 37℃ water bath for TTC dissolved, the frozen brain tissue slices, placed in 10ml TTC solution, 37℃,10min. Normal brain tissue staining was bright red, and the infarct area was pale.

Take the brain, 4% poly Formaldehyde Solution fixed, after dehydration of sucrose solution, the OCT embedded to make the frozen section (slice 10um), Nissl staining and the staining resluts are used for the evaluation of infarct size.

SPSS software is used for statistical analysis, measurement data to mean ± standard deviation (x ±ｓ), using t test and single factor analysis of variance for group comparison , P<0.05 indicates there was a significant difference, P<0.01 indicates there are very significant differences.