Biopsies from controls and PBS patients will be obtained in either general or spinal anesthesia transurethrally from the bladder dome and trigone with a biopsy tong. RNA will be extracted, and the expression levels of selected genes analyzed using Taqman real-time PCR and gene expression arrays (Applied Biosystems). Calcium imaging will be used to monitor the receptor activation and protein levels analysed by SDS-PAGE and Western Blotting. Receptor tissue distribution will be analysed by immuno-cytochemistry.