Vesicles containing pro-BDNF–p75NTR express the Vamp2 component of the SNARE core complex for vesicle fusion. (A) Colocalization between GFAP, pro-BDNF, and Vamp2 immunoreactivity in astrocytes 10 min after TBS. Colocalization signal (arrowheads) is shown at the site of astrocytic contact with a neuron (box and inset 1) and astrocytic processes (box and inset 2). Bar, 20 μm. (B) Immunocytochemistry showing colocalization between pro-BDNF–QDs and Vamp2 in astrocytes transfected with p75-GFP. Right panels depict QD/Vamp2 colocalization (arrowheads) in a selected astrocytic area (boxed area). Bar, 2 μm. (C) Western blot showing p75NTR and Vamp2 expression in endocytic vesicles immunopurified (IP) by magnetic beads coated with α-p75NTR, α-Vamp2, or α-Map2 from astrocytes untreated or treated with BDNF (mix).
