Heterogeneous Intracellular Trafficking Dynamics of Brain-Derived Neurotrophic Factor Complexes in the Neuronal Soma Revealed by Single Quantum Dot Tracking
(A) Embryonic (E) 16.5 NG neurons incubated with QD-BDNF probes showed survival rates equivalent to unmodified BDNF (400 pM), while incubations with streptavidin-QDs did not. Neurons incubated with unmodified BDNF, streptavidin-QD and QD-BDNF (72 hr) are identified by anti-neurofilament (NF68/180) antibodies. (B) Quantitation of results shown in (A). Neuronal survival induced by QD-BDNF was indistinguishable from unmodified BDNF (ANOVA, p<0.0001, Dunnett's post-hoc test, n = 4). Density of neurofilament (NF68/180) immunoreactive (IR) cells increased as a function of BDNF and QD-BDNF concentration. (C) QD-BDNF-dependent survival is TrkB specific as pre-block with anti-TrkB receptors and subsequent QD-BDNF treatment decreased NG neurons survival (ANOVA, p<0.0001, Dunnett's post-hoc test, n = 5). Scale bar: 50 µm.