Effect of FcRγ deficiency on thrombus formation in a laser-induced arterial thrombosis model. Severe (A-B) or moderate (C-D) laser-induced lesions were generated in the mesenteric arteries of wild-type and FcRγ^–/– mice and the surface area of developing thrombi assessed as described previously.²²  (A,C) Traces represent the mean surface area (± SEM) of the thrombi developing over 150 seconds (WT: n = 12 vessels in 8 mice; FcRγ^–/–: n = 12 vessels in 7 mice). Analysis of mean surface area of thrombi formed in severely injured vessels indicate no significant difference in thrombus formation between wild-type and FcRγ^–/– mice (P > .05). In contrast, following moderate injury there was a 30% reduction in the size of thrombi formed in FcRγ^–/– mice relative to wild-type mice (WT: n = 19 vessels in 7 mice; FcRγ^–/–: n = 29 vessels in 9 mice). Time sequence images of platelet thrombi forming in wild-type and FcRγ^–/– mice subjected to severe (B) or moderate (D) injury. Arrow indicates blood flow direction.