BDNF acts as a platelet primer to other classical agonists. Example trace and quantification of platelet aggregation of platelets pre-incubated with BDNF (40 nM) in response to subthreshold concentrations of collagen (A) (0.125-0.5 µg/mL; repeated-measures ANOVA test, P = .01; compared with vehicle, both BDNF and collagen, P > .05; compared with collagen alone, collagen + BDNF, P = .005), arachidonic acid (B) (0.5-2.5 µM; repeated-measures ANOVA test, P = .208), TRAP (C) (0.5 µM; repeated-measures ANOVA test, P = .0002; compared with vehicle, both BDNF and TRAP, P > .05; compared with TRAP alone, TRAP + BDNF, P = .008), and ADP (D) (0.5 µM; repeated-measures ANOVA test, P = .03; compared with vehicle, both BDNF and ADP, P > .05; compared with ADP alone, ADP + BDNF, P = .07). Example trace and quantification of platelet aggregation in the presence of the BDNF-neutralizing antibody (mab#9) in response to 1 µg/mL collagen (E) (repeated-measures ANOVA, P < .0001; compared with vehicle, collagen alone and/or in presence of mab#9, P < .0001; compared with collagen alone, collagen in the presence of mab#9, P > .05), 10 µM arachidonic acid (F) (repeated-measures ANOVA, P < .0001; compared with vehicle, arachidonic acid alone and/or in the presence of mab#9, P < .0001; compared with arachidonic acid alone, arachidonic acid in the presence of mab#9, P > .05); 3 µM TRAP (G) (repeated-measures ANOVA, P < .0001; compared with vehicle, TRAP alone and/or in the presence of mab#9, P < .0001; compared with TRAP alone, TRAP in the presence of mab#9, P > .05); and 10 µM ADP (H) (repeated-measures ANOVA, P = .01; compared with vehicle, ADP alone, P < .0001; compared with ADP in the presence of mab#9, both vehicle and ADP alone, P > .05). Arrowheads indicate the time point at which the agonist was added. Data are presented as median and IQR.