Blockade of platelet GPIbα reduces platelet VWF-mediated ischemic stroke injury. Transient focal cerebral ischemia was induced by 60 minutes occlusion of the right middle cerebral artery, followed by 23 hours of reperfusion in nontreated WT (n = 6) and VWF KO (n = 5) mice, and VWF PLT chimeric mice treated with 100 μg anti-GPIbα Fab (+ p0p/B; n = 8) or rat IgG Fab control (+ IgG Fab; n = 12). (A) Representative 2,3,5-triphenyltetrazolium chloride staining of 3 consecutive coronal brain sections 24 hours after transient middle cerebral artery occlusion (tMCAO). White color indicates infarcted area, whereas a pink color shows unaffected brain tissue. (B) Brain infarct volumes as quantified by planimetric analysis 24 hours after tMCAO. ns, not statistically significant. **P < .01.