Validation of a preclinical animal model to assess brain recovery after acute stroke

This study was to validate the animal model for the research in the stage of recovery and sequela of ischemic stroke. For its recognized many advantages and widespread applications, middle cerebral artery occlusion / reperfusion (MCAO/R) in Male Sprague-Dawley rats was chosen to be the foundation model. Then the weight of rats (260-330 g), the thread bolt type (2636/2838/3040/3043), the time of brain infarct (2/3 h) were tested to choose the larger infarct volume, higher Longa's score and model success rate through Longa's score and TTC staining. Finally, optimum condition of model was used in long period observing from 1 to 90 days after MCAO/R via five assessment of sensorimotor functions and TTC staining. The results showed that the optimal rat model of cerebral infarction in the stage of recovery and sequela of ischemic stroke maybe the model rats which were 300 g weight and MCAO with 3040 line-lock for 3 h before reperfusion. In these conditions, the Longa's score was 2.1 ± 0.2, and infarct volume was 23.0 ± 2.4%. The sensorimotor functional test of bilateral asymmetry had significant difference from 1 to 90 days, the test of grid-walking had significant difference from 1 to 60 days, while other tests had significant difference only at 1 day after MCAO/R. In conclusion, 3040-300 g-3 h was the most appropriate condition, and the appropriate index of sensorimotor functions were bilateral asymmetry and grid-walking test.