Locomotor Exercise Enhances Supraspinal Control of Lower-Urinary-Tract Activity to Improve Micturition Function after...

Area of Science:

• Neuroscience
• Urology
• Rehabilitation Medicine

Background:

• Lower urinary tract dysfunction is a significant complication for individuals with spinal cord injury.
• Locomotor training has historically shown promise in improving micturition function.

Purpose of the Study:

• To investigate if locomotor training enhances supraspinal control of the external urethral sphincter, leading to improved detrusor-sphincter activity coordination.
• To assess the impact of forced wheel running exercise on voiding function and neurological recovery following spinal cord injury.

Main Methods:

• A contusive spinal cord injury model was established in rats at the T12 level.
• Rats underwent 11 weeks of forced wheel running exercise.
• Bladder function and sphincter activity were assessed using cystometrogram and electromyography; neural tracing and immunohistochemistry were employed to evaluate supraspinal innervation.

Main Results:

• Locomotor training reduced nonvoiding bladder contractions and lowered the voiding threshold.
• Training improved voiding efficiency by shortening sphincter latency and decreasing peak intravesical pressure.
• Histological analysis revealed increased spared spinal cord tissue, enhanced 5-HT innervation of Onuf's motoneurons, and increased brainstem neuronal activation.

Conclusions:

• Locomotor training promotes tissue sparing and enhances supraspinal control of Onuf's motoneurons following spinal cord injury.
• These neuroplastic changes contribute to the observed improvements in voiding function and detrusor-sphincter coordination.
• Locomotor training represents a viable strategy for functional recovery of the lower urinary tract after spinal cord injury.