Cross-talk and sensitization of bladder afferent nerves.

The coordination of pelvic physiologic function requires complex integrative sensory pathways that may converge both peripherally and/or centrally. Following a focal, acute irritative or infectious pelvic insult, these same afferent pathways may produce generalized pelvic sensitization or cross-sensitization as we show bi-directionally for the bladder and bowel in an animal model. Single unit bladder afferent recordings following intracolonic irritation reveal direct sensitization to both chemical and mechanical stimuli that's dependent upon both intact bladder sensory (C-fiber) innervation and neuropeptide content. Concurrent mastocytosis (preponderantly neurogenic) likely plays a role in long-term pelvic organ sensitization via the release of nociceptive and afferent-modulating molecules. Prolonged pelvic sensitization as mediated by these convergent and antidromic reflexive pathway may likewise lead to chronic pelvic pain and thus the overlap of chronic pelvic pain disorders.