Heterogeneous Intracellular Trafficking Dynamics of Brain-Derived Neurotrophic Factor Complexes in the Neuronal Soma Revealed by Single Quantum Dot Tracking
(A) Single cell assays show QD-BDNF probes (400 pM) bind preferentially to TrkB-expressing nodose (NG) and cortical (CORT) neurons vs. non-TrkB expressing control N2A neural cell lines. Control streptavidin-QD (400 pM) treatment typically showed non-specific binding levels of 0–2 QD/cell (white arrows; see text for more details). Collapsed z-stack micrographs (total cell height at 22–25 µm for NG, 5–8 µm for CORT and N2A). Scale bars: 10 µm. (B) Population assays by QD fluorescence measurement in neuronal lysates. Neurons treated with either QD-BDNF or streptavidin-QD (400 pM; black bars, red bars/arrows respectively), washed, and lysed. Positive control = TrkB receptor, negative control = lysis buffer blank.