BDNF-induced β1-integrin clustering requires intact lipid microenvironments and functional β1-integrin. (A) Representative immunolabeled images showing β1-integrin after vehicle (BSA), BDNF (50 ng/mL; 20 min), (B) L-t-LacCer (20 μM) and L-t-LacCer plus BDNF, and (C) β1-integrin function blocking antibody (Fxn Blk Ab, 5 μg/mL) alone and plus BDNF treatments. Arrowheads designate clustered β1-integrins. Scale bar, 5 μm. (D) Quantification of β1-integrin clustering according to the treatment groups. Data are the mean ± standard error of the mean. (n > 150, **P < 0.001, ANOVA with Tukey's post hoc analysis.) BDNF: brain-derived neurotrophic factor; BSA: bovine serum albumin; L-t-LacCer: β-D-lactosyl-N-octanoyl-L-threo-sphingosine.