Overexpression of hPLS3 restores TrkB phosphorylation and Akt phosphorylation in Smn-deficient motor axon terminals. (A) LV-mCh and LV-hPLS3 transduced control and Smn^−/−;SMN2 growth cones unstimulated and 20 min 8-CPT-cAMP stimulated stained against surface TrkB (gray) and Synaptophysin-1 (SYP, magenta). Normalized mean gray values of surface TrkB (N = 4, n = 115; ANOVA Kruskal–Wallis, ***P ≤ 0.001; ****P ≤ 0.0001). (B and C) Unstimulated or 15 min BDNF stimulated growth cones from control and Smn^−/−;SMN2 motoneurons transduced with LV-mCh and LV-hPLS3 stained against (B) p-TrkB (gray) or (C) p-Akt (gray) and F-actin (Phalloidin, yellow). (B) Normalized mean gray values of p-TrkB in LV-mCh or LV-hPLS3 transduced control and Smn^−/−;SMN2 terminals (N = 4, n = 105; ANOVA Kruskal–Wallis, ****P ≤ 0.0001). (C) Normalized mean gray values of p-Akt in LV-mCh or LV-hPLS3 transduced control and Smn^−/−;SMN2 terminals (N = 4, n = 98; ANOVA Kruskal–Wallis, *P ≤ 0.05; ****P ≤ 0.0001). Data are presented as scatter dot plot with bar. Bar represents the mean ± SEM. Scale bars: 5 µm.