Figure 5. CHF impairs synaptic ultrastructure in the hippocampus. (A) Representative ultrastructural images of synapses shown at magnifications of × 4000, scale bars: 10 μm; × 15000, scale bars: 4 μm; × 50000, scale bars: 1 μm, respectively. (B–F) Quantifications of the synaptic interface, including synapse density (B), PSD thickness (C), active zone length (D), synaptic cleft (E), and synaptic curvature (F) n = 3. (G–K) Representative Western blots (G) and quantitative data of PSD95 (H), Synapsin I (I), PDE4 (J), p-CREB and CREB (K). β-actin was used as a loading control n = 3. (L) The content of cAMP in the hippocampus detected by ELISA. (M) The activity of PKA in the hippocampus detected by ELISA n = 6. Data are presented as the Mean ± SEM; *P < 0.05, and **P < 0.01 vs. Sham.