SLAP/SLAP2 deficiency in platelets induces a dramatic increase in infarct volume in a model of ischemic stroke. Infarct volumes (A) and functional outcome (B-C) 24 hours after focal cerebral ischemia in WT mice reconstituted with WT or Slap^−/−/Slap2^−/− (DKO) platelets after depletion of endogenous platelets were investigated in a murine model of ischemic stroke. Mice were subjected to 30 minutes of tMCAO. (A) Brain infarct volumes in platelet-depleted WT mice transfused with WT (n = 12) or Slap^−/−/Slap2^−/− (n = 8) platelets were measured by planimetry (left). Results represent mean ± SD. Representative images of 3 coronal brain sections stained with 2,3,5-triphenyltetrazolium chloride for 24 hours after 30 minutes of tMCAO (right). Arrows indicate infarcted areas in WT mice recipients of Slap^−/−/Slap2^−/− platelets. Bederson score (B) and grip test (C) were determined 24 hours after tMCAO. Each symbol represents 1 animal. *P < .05; ***P < .001. DKO, double knockout; plts, platelets.