G1-induced activation of mTOR signaling involves BDNF release. (A–D) Hippocampal slices were preincubated with IgG-Fc or TrkB-Fc for 1 h and then treated with G1 for an additional 30 min. At the end of treatments, samples were homogenized and processed for Western blotting. Data are presented as the ratio (fold of control) of: (A) PTEN over actin (n = 10–12), (B) phospho-Akt (p-Akt) over total Akt (n = 11–13), (C) phospho-mTOR (p-mTOR) over total mTOR (n = 9–14), and (D) αCaMKII over actin (n = 13–16). (E) Primary cortical neurons were preincubated with TrkB-Fc for 1 h and then treated with G1, E₂, PPT, or DPN for an additional 60 min. The incubation medium was collected, concentrated, and processed for Western blotting. BDNF over TrkB (n = 4–8) is shown. *, P < 0.05; **, P < 0.01; ***, P < 0.001, as compared with control. #, P < 0.05; ##, P < 0.01; ###, P < 0.001, as compared with G1 alone (one- or two-way ANOVA). Black lines indicate that intervening lanes have been spliced out. Error bars indicate means ± SEM.