Fig. 4

PACAP6-38 administration decreased the overexpression of synaptic-associated proteins and restored the aberrant synaptic ultrastructure in CM rat model. A-C. Representative bands and quantification of PSD-95, syt-1 and syp protein levels showed that these proteins were significantly increased in the NTG + vehicle group compared to the saline + vehicle group, while PACAP6-38 blocked these effects. E–G. Representative images of the synaptic ultrastructure in the four groups. H-J. The width of the synaptic cleft (H) was decreased, and the thickness of PSD (I) and the synaptic interface curvature (J) were significantly increased in the NTG + VEHgroup compared to the Saline + VEHgroup. In the NTG + PA6-38 group, these abnormal alterations were alleviated. Mean ± SEM. n = 3/group. One-way ANOVA with Dunnett’s post hoc test; Scale bars = 500 nm. *p < 0.05, **p < 0.01, ***p < 0.001 compared with saline + vehicle group, ^&p < 0.05, ^&&p < 0.01, ^&&&p < 0.001 compared with NTG + vehicle group. Abbreviations: PA6-38, pituitary adenylate cyclase-activating peptide 6–38; NTG, nitroglycerin; CM: chronic migraine