ASIC2a-IR in cryostat sections of CYP-treated urothelium. CYP treatment [4 h (b and d) and 48 h (c and e)] significantly (P ≤ 0.05) increased the percentage of ASIC2a-IR in urothelium compared with control (a). c: confocal z-stack image demonstrating ASIC2a-IR in urothelium and diffuse ASIC2a in lamina propria (LP) and in putative nerve fibers (arrows). d and e: higher-power fluorescence images of ASIC2a-IR in urothelium after 4 h and 48 h of CYP-induced cystitis. For all images, exposure times were held constant, and all tissues were processed simultaneously. In rats treated with CYP for 4 and 48 h, ASIC2a expression was visible in urothelium (b–e), whereas control (a) urinary bladder showed little or no ASIC2a-IR. Calibration bar represents 50 μm in a–c and 25 μm in d and e. L, lumen. f: ASIC2a expression above threshold in urothelium of CYP-treated (4 h and 48 h) rats expressed as a percentage of control. Semiquantitative analyses were performed as described in Fig. 5 legend. CYP treatment (4 h and 48 h) significantly (P ≤ 0.01) increased ASIC2a-IR in urothelium (n = 6 for each group).