Fig. 1

The expression of BDNF-TrkB signaling in the SDH of CYP-induced cystitis. a Changes of the mechanical threshold in CYP-induced cystitis model. Compared to that in the control group, the mechanical threshold of the cystitis group decreased significantly after the CYP injection and remained low until day 17, and the minimum threshold value was reached on day 12. The expression of b BDNF, c TrkB, and d p-TrkB were evaluated by western blots. Compared to the control group, they were upregulated on days 8, 12, and 17. e Immunofluorescence double staining assay of BDNF and p-TrkB in the SDH. BDNF and p-TrkB (red), NeuN, GFAP, and OX-42( green), co-localization (yellow). BDNF was mainly colocalized in neurons which mainly located in Laminate II to IV. And TrkB receptors expressed in neurons, microglia, and astrocytes. The white dotted lines in picture “BDNF/NeuN” showed the laminate of the SDH according to Rexed and Steiner. Scale bar = 100 μm. All data were calculated as mean ± SEM (n = 5 per group). *p < 0.05, ** p < 0.01, *** p < 0.001 vs. the control group