Colonic inflammation increases Na+ currents in bladder sensory neurons

Area of Science:

• Neuroscience
• Gastroenterology
• Urology

Background:

• Colonic inflammation can trigger referred sensations and pain in the lower urinary tract.
• The role of specific ion channels in bladder sensory neurons during colonic inflammation is not fully understood.

Purpose of the Study:

• To investigate if colonic inflammation sensitizes pre-spinal afferents innervating the urinary bladder.
• To examine the physiological changes in bladder sensory neurons following experimental colitis.

Main Methods:

• Experimental colitis was induced in a preclinical model.
• Dorsal root ganglia (DRG) neurons innervating the bladder were retrogradely labeled.
• Tetrodotoxin-resistant (TTX-R) Na+ currents were recorded in capsaicin-sensitive bladder sensory neurons.

Main Results:

• Colitis significantly increased the response of bladder neurons to capsaicin by approximately 60%.
• The peak amplitude of tetrodotoxin-resistant (TTX-R) Na+ currents in these neurons was enhanced by 51% after colitis.
• These findings indicate heightened excitability in nociceptive bladder neurons.

Conclusions:

• Colonic inflammation induces sensitization of bladder afferent neurons.
• Increased neuronal excitability in the bladder may contribute to symptoms associated with colonic inflammation.
• Targeting these sensitized pathways could offer therapeutic strategies for managing referred pain.