UPEC Infection results in histological changes and bladder hyperalgesia. A. 24 hour infection with uropathogenic E. coli (UPEC) increases the VMR to bladder distention when compared to mock-infected (PBS) littermates. B. Infection with UPEC results in an increased infiltration of polymorphonuclear leukocytes (arrowheads), and a sloughing of the superficial facet cells. C. Distention alone does not result in the loss of superficial facet cells (arrows,). +/- SEM *p < 0.05, **p < 0.01, ***p < 0.001. Unpaired 2-way ANOVA with Bonferroni post-hoc test.