Changes in afferent activity after spinal cord injury

Area of Science:

• Neuroscience
• Urology
• Regenerative Medicine

Background:

• Spinal cord injury (SCI) disrupts neural pathways controlling bladder function.
• The micturition reflex involves complex spinobulbospinal pathways modulated by higher brain centers.
• Bladder afferent neurons play a critical role in coordinating bladder and sphincter function.

Purpose of the Study:

• To summarize alterations in bladder afferent neuron properties post-spinal cord injury.
• To elucidate the mechanisms underlying bladder dysfunction after SCI.
• To review the role of neuronal plasticity in recovery of bladder function.

Main Methods:

• Comprehensive literature review of anatomical, immunohistochemical, and pharmacologic studies.
• Analysis of animal models investigating bladder afferent pathways.
• Synthesis of data on normal and dysfunctional micturition reflexes.

Main Results:

• SCI disrupts voluntary voiding and normal reflex pathways.
• Bladder function transitions from areflexic to hyperreflexic post-SCI due to a spinal micturition reflex.
• Neuronal plasticity, including morphologic and chemical changes in afferent neurons, is crucial for functional recovery.
• Neurotrophic factors contribute to afferent pathway plasticity.

Conclusions:

• SCI indirectly influences bladder afferent neurons by altering the spinal cord and bladder microenvironment.
• Changes in neuronal properties are key to understanding and potentially treating bladder dysfunction after SCI.
• Targeting neurotrophic factors and promoting plasticity may enhance bladder function recovery.