Animal studies suggest that antimuscarinic drugs can inhibit sensory nerves. The presence of acetylcholine release was confirmed in human isolated bladder epithelium. Moreover, the presence of multiple M receptors in bladder epithelial and submucosal myofibroblasts suggests a role for M receptors in bladder epithelial sensory mechanisms. The release of acetylcholine during the storage phase enhances the contractile activity of the detrusor fibers, which results in sensory afferent impulses. All of these suggest that antimuscarinic drugs can reduce bladder sensory afferent impulses by blocking M receptors at these sites, thereby improving OAB symptoms.