Measurement of Infarct Volume

Twenty‐four hours after MCAO, cerebral infarct size was determined by 2,3,5 triphenyltetrazolium chloride staining. Brains were cut from the frontal pole into 1‐mm‐thick serial coronal sections using a mouse Brain Matrix (Roboz surgical instrument). Sections were stained with 1% triphenyltetrazolium chloride at 37°C for 15 minutes at 37°C then fixed in 10% neutral buffered formalin. Sections were scanned and infarct area was determined by a person blinded to the study and analysis was performed using National Institutes of Health Image J software. To correct for brain swelling because of edema after ischemia the corrected total infarct volume (%) was calculated as described: Corrected infarct volume (%)=[volume of contralateral hemisphere−(volume of ipsilateral hemisphere−volume of infarct)]/volume of contralateral hemisphere×100.31