Fig. 1.

BDNF activates R-Ras and promotes R-Ras-mediated axonal growth. (A) Cortical neurons at 3 DIV were treated with 50 ng/mL of BDNF or vehicle control for 30 min. Activated R-Ras was isolated with GST-Ras-binding domain (RBD) of c-Raf-1 and detected by the R-Ras specific antibody. (B) Densitometry analysis was performed, and GTP-R-Ras/total R-Ras ratio was determined. Relative R-Ras activity compared to vehicle-treated cells is shown. Data are presented as the means ± SEM of four independent preparations, **p < 0.01. (C) Neurons were transfected with YFP and shRNAs at 1 DIV, then 50 ng/mL of BDNF was added to 2 DIV culture medium, and incubated for 24 h before fixation. Scale bar, 50 µm. (D, E) The effects on axon length (D) and branching (E) were quantitatively analyzed and expressed as means ± SEM of 54 cells in three independent preparations, *p < 0.05; ***P < 0.001; ns, not significantly different.