Membranous and cytoplasmic expression of BDNF and TrkB depending on culture conditions.

<p>Confocal microscopy of WiDr (A, B) and COLO 205 (C, D) cells, stained with an anti-BDNF Ab (red), anti-TrkB mAb (green) or both (overlay) cultured with 10% FCS (A, C) or after 24-h serum deprivation (B, D). Under basal culture conditions (10% FCS), TrkB and BDNF were sequestered in the cytoplasm (arrows) in WiDr (A) and COLO 205 (C) cells. The same staining patterns were obtained with the two other cell lines (data not shown). After serum starvation relocation to the cell membrane and colocalization of TrkB and BDNF (yellow in merged, arrows) were detected in WiDr (B) and COLO 205 (D). Images were representative for at least three to five independent experiments.