Fig. 5

Tianeptine’s effect on BDNF intracellular transport and AMPAR surface diffusion is mediated by BDNF-TrkB signaling pathway. a Representative kymographs of intracellular transport of BDNF-containing vesicles (white trajectories) in a neurite (50 μm from soma) over 75 s in polyQ-HTT-expressing rat hippocampal neurons treated with vehicle, tianeptine (50 μM), or Cyclotraxin-B (CB) (1 μM) plus tianeptine (50 μM). b, c Anterograde and retrograde BDNF transport velocity in all neurites of polyQ-HTT-expressing rat hippocampal neurons treated with vehicle, tianeptine (50 μM), or CB (1 μM) plus tianeptine (50 μM) (b) or treated with vehicle, BDNF (100 ng ml⁻¹), tianeptine (10 μM), or BDNF (100 ng ml⁻¹) plus tianeptine (10 μM) (c); values are median ± 95% c.i. (b, c); n = 4322, 4017, 4199, 4354, 3887, and 3954 trajectories for anterograde and retrograde velocity in polyQ-HTT-expressing neurons treated with vehicle, tianeptine, and CB plus tianeptine, respectively (b); n = 3505, 3382, 3339, 2099, 3346, 3174, 3190, and 2022 trajectories for anterograde and retrograde velocity in polyQ-HTT-expressing neurons treated with vehicle, BDNF, tianeptine, and BDNF plus tianeptine, respectively (c). d Typical GluA2-QD trajectories (magenta) in polyQ-HTT-expressing rat hippocampal neurons, treated with vehicle, tianeptine (50 μM), CB (1 μM) plus tianeptine (50 μM), or TrkB-Fc (1 μg ml⁻¹) plus tianeptine (50 μM). Scale bar, 10 μm. e GluA2-AMPAR diffusion coefficients in FL-polyQ-HTT-expressing rat hippocampal neurons treated with vehicle, tianeptine (50 μM), CB (1 μM), plus tianeptine (50 μM), or TrkB-Fc (1 μg ml⁻¹) plus tianeptine (50 μM); data are shown as median ± 25–75% IQR; n = 601, 535, 708, and 556 trajectories for 4 groups, respectively. Data are representative of a minimum of three independent experiments. Significance was assessed by Kruskal–Wallis test followed by Dunn’s multiple comparison test (b, c, e); ***P < 0.001; ns not significant