Bladder afferents and their role in the overactive bladder.

Area of Science:

• Urology
• Neuroscience
• Physiology

Background:

• Afferent bladder innervation is crucial for normal bladder function and continence.
• Spinal cord injury alters bladder afferent pathways, leading to neurogenic detrusor overactivity.
• Understanding these neural pathways is key to developing effective treatments for urinary incontinence.

Purpose of the Study:

• To investigate the role of bladder afferent innervation in urinary incontinence pathophysiology.
• To explore the differences between normal and spinal-disrupted afferent pathways.
• To evaluate the potential of targeting specific afferent fibers for therapeutic interventions.

Main Methods:

• Review of ultrastructural investigations of bladder neural elements.
• Analysis of afferent pathway mediation by Adelta-fibers and capsaicin-sensitive C-fibers.
• Examination of treatment outcomes using capsaicin and resiniferatoxin.

Main Results:

• In normal bladders, Adelta-fibers mediate fullness sensation.
• After spinal disruption, C-fibers drive a spinal reflex causing neurogenic detrusor overactivity.
• Intravesical capsaicin/resiniferatoxin successfully treated neurogenic incontinence by targeting C-fibers.

Conclusions:

• Emergent C-fiber pathways are implicated in neurogenic detrusor overactivity and incontinence.
• Targeting capsaicin-sensitive C-fibers offers a viable treatment strategy for neurogenic incontinence.
• Further research into neurotoxins acting on afferent innervation may yield new treatments for bladder disorders.