The bladder-brain connection: putative role of corticotropin-releasing factor

The coordination of pelvic visceral activity with appropriate elimination behaviors is a complex task that requires reciprocal communication between the brain and pelvic organs. Barrington's nucleus, located in the pons, is central to a circuit involved in this function. Barrington's nucleus neurons project to both pelvic visceral motorneurons and cerebral norepinephrine neurons that modulate behavior. This circuit coordinates the descending limb of the micturition reflex with a central limb that initiates arousal and shifts the focus of attention to facilitate elimination behavior. The same circuitry that links the bladder and brain enables pathological processes in one target of the circuit to be expressed in the other. Urological disorders can, therefore, have cognitive and behavioral consequences by affecting components of this circuit; and in the opposing direction, psychosocial stressors can produce voiding dysfunctions and bladder pathology. The stress-related neuropeptide, corticotropin-releasing factor, which is prominent in Barrington's nucleus neurons, is a potential mediator of these effects.