Delayed spreading of n-cofilin–null, but not Adf^−/− platelets on fibrinogen. (A) Thrombin-activated (0.001 U/mL) platelets were allowed to spread on immobilized human fibrinogen (1 mg/mL). Platelets were fixed at different time points and counted. Differential interference contrast images were recorded after 20 minutes. Bar represents 4 μm. (B) SEM after plasma membrane denudation of platelets spread for 60 minutes on fibrinogen. Scale bar represents 2 μm. (C) STED microscopy of platelets spread for 60 minutes on fibrinogen and stained with phalloidin. Scale bar represents 3 μm.