Quantification of brain infarct volume in TNFα-transgenic and non-transgenic rats at 24 hours. Representative infarcts are shown in the brain of a non-transgenic (Panel a) and a TNFα-transgenic (TNFα-Tg) rat (Panel b). In Panel c, a bar graph shows mean percent infarct volume in both TNFα-Tg and non-Tg rats. All animals underwent suture-occlusion of the right middle cerebral artery for one hour followed by 24 hours of post-ischemic reperfusion. The 1-mm coronal brain sections in Panels a and b were stained for triphenyltetrazolium chloride. Panel a shows infarction (blanched tissue) confined to the right cortical mantle and a portion of the underlying striatum in a non-Tg rat. In the transgenic animal shown in Panel b, there is blanching of tissue in the right cortical mantle that indicates completed infarction and mottled discoloration throughout the entire ipsilateral striatum that is a maturing infarct. Panel c shows that mean ± SD infarct volume in the transgenic group (n = 12) was significantly greater than that of the non-Tg group (n = 17; *p ≤ 0.05; unpaired t test). All volume measurements were corrected for tissue edema.