Figure 4

Regulation of BDNF-TrkB pathway underlies HTP-GTE-dependent amelioration of hippocampal synaptic impairments in helpless OVX rats. (a, b) Western blot of BDNF level in hippocampus on sham-OVX resilient + vehicle, OVX helpless + vehicle, OVX + HTP-GTE 200 mg/kg, and OVX + HTP-GTE 400 mg/kg groups in oral administration of HTP-GTE or vehicle solution daily for 4 weeks (Sham-OVX resilient + vehicle: 1.00 \(\pm \) 0.07; OVX helpless + vehicle: 0.69 \(\pm \) 0.01; OVX + HTP-GTE 200 mg/kg: 1.11 \(\pm \) 0.03; OVX + HTP-GTE 400 mg/kg: 1.20 \(\pm \) 0.05, n = 3 brains/group). Full-length blot is presented in Supplementary Fig. S13. (c,d) Western blot of BDNF level in hippocampus of exogenous application of HTP-GTE for 2 h (Sham-OVX resilient + exo-vehicle: 1.0 \(\pm \) 0.04; OVX helpless + exo-vehicle: 0.71 \(\pm \) 0.05; OVX helpless + exo-HTP-GTE 40 μg/ml: 1.01 \(\pm \) 0.04, n = 3 brains/group). Full-length blot is presented in Supplementary Fig. S13. (e–j) Top: representative traces showing EPSPs before (average of 20 traces, black line) and after (average of 180 traces, red line) high-frequency stimulus. Bottom: average time courses for EPSP amplitudes during LTP induction in all groups. (k,l) Quantified graph was shown (Sham-OVX resilient + exo-vehicle: 137.4 \(\pm \) 1.02, n = 5 slices/3 rats; OVX helpless + exo-vehicle: 107.6 \(\pm \) 3.18, n = 8 slices/3 rats; OVX helpless + exo-BDNF (8 nM): 136.0 \(\pm \) 5.74, n = 6 slices/3 rats; OVX helpless + exo-BDNF (8 nM) + exo-cyclo B: 112.8 \(\pm \) 2.27, n = 6 slices/3 rats; OVX helpless + exo-HTP-GTE 40 μg/ml: 157.9 \(\pm \) 7.21, n = 7; OVX helpless + exo-HTP-GTE 40 μg/ml + cyclo B: 113.4 \(\pm \) 7.64, n = 6). Data are represented as mean \(\pm \) SEM (One-way ANOVA Tukey’s post hoc test, **p < 0.01, ***p < 0.001).