The evolving physiology of the lower urinary tract: What we are learning and where we need to go

Abstract

Much of the current research on the physiology of the lower urinary tract is focused on afferent mechanisms, and we are learning how to control two of the identified signaling pathways by which afferent information is generated and conveyed to the central nervous system: the myogenic and urothelial (mucosal) pathways. The myogenic pathway is activated via “in series” mechanoreceptors responding to distention and via spontaneous contractile activity in units of myocytes generating “afferent noise.” The mucosal pathway is a functional unit consisting of the urothelium itself, suburothelial interstitial cells, and afferent nerves that signal via muscle-mucosal mechanoreceptors, mucosal mechanoreceptors, and chemoreceptors. To control micturition when it is dysfunctional, we need to know more about all the components involved in normal micturition regulation. These include central control mechanisms. More information is needed to understand brain control of bladder function and to develop centrally acting agents to control bladder activity.