Bladder Afferent Signaling: Recent Findings

Purpose

Much current research on lower urinary tract physiology focuses on afferent mechanisms. The main goals are to define and control the signaling pathways by which afferent information is generated and conveyed to the central nervous system. We summarize recent research on bladder afferent mechanisms.

Materials and Methods

We systematically reviewed the literature by searching PubMed® up to June 2009 with focus on the last 5 years.

Results

At least 2 signaling pathways can be identified, including the urothelial and the myogenic pathway. The urothelial pathway is a functional unit consisting of the urothelium, interstitial cells and afferent nerves in the lamina propria. Signaling occurs via muscle-mucosal mechanoreceptors, mucosal mechanoreceptors and chemoreceptors. The myogenic pathway is activated via in-series mechanoreceptors responding to distention and via spontaneous contractile activity in units of myocytes generating afferent noise.

Conclusions

To control dysfunctional micturition we must know more about all components involved in normal micturition control, including how afferent information is handled by the central nervous system.

Key Words: urinary bladder, afferent pathways, muscle contraction, urothelium, urination disorders

Abbreviations And Acronyms: ATP, adenosine triphosphate, DO, detrusor overactivity, DRG, dorsal root ganglia, ICC, interstitial cells of Cajal, LUT, lower urinary tract, OAB, overactive bladder, RTX, resiniferatoxin, TRP, transient receptor potential