BDNF induces complete, biphasic platelet aggregation in washed platelets. Representative trace (A) and quantification (B) of platelet aggregation in response to 40, 125, and 370 nM BDNF. Repeated-measures ANOVA, P = .0004; vehicle vs 125 nM BDNF, P = .01; vehicle vs BDNF 370 nM, P < .0001. Example trace (C) and quantification (D) of neutralization of BDNF-induced aggregation by the mab#9 antibody (2.5 µg/mL). IgG_2B was used as an isotype control (2.5 µg/mL). Results are representative of ≥5 independent experiments. Repeated-measures ANOVA, P < .0001; BDNF 370 nM vs BDNF 370 nM in the presence of mab#9, P < .0001. Example trace (E) and quantification (F) of BDNF-induced platelet aggregation in the presence of inhibitors of secondary mediators (30 µM aspirin, 1 µM AR-C66096 (ARC), and 9 µM eptifibatide (Integrilin)). Results are representative of 5 independent experiments. Repeated-measures ANOVA, P < .0001; compared with BDNF 370 nM: inhibition with aspirin, P = .001; inhibition with AR-C66096, P = .0002; and inhibition with eptifibatide, P < .0001. Arrowheads indicate the time point at which the agonist was added. Data are presented as median and IQR.