Spinal cord injury (SCI) causes dramatic changes in quality of life including coping with bladder dysfunction which requires repeated daily and nightly catheterizations. Our lab has recently demonstrated in a rat SCI model that repetitive sensory information generated through task-specific stepping and/or loading can improve non-locomotor functions, including bladder function. To target potential underlying mechanisms, the current study included a forelimb-only exercise group to ascertain whether improvements may be attributed to general activity effects that impacts target organ-neural interactions or to plasticity of the lumbosacral circuitry that receive convergent somato-visceral inputs. Male Wistar rats received a T9 contusion and were randomly assigned into three groups two weeks post-injury - quadrupedal locomotion, forelimb exercise, or a non-trained group. Throughout the study (including pre-injury), all animals were placed in metabolic cages once a week for 24 hours to monitor water intake and urine output. Following the 10-week period of daily one-hour treadmill training, awake cystometry data were collected and bladder and kidney tissue harvested for analysis. Metabolic cage frequency-volume measurements of voiding and cystometry reveal an impact of exercise training on multiple SCI induced impairments related to various aspects of urinary tract function. Improvements with both quadrupedal and forelimb trained groups implicate underlying mechanisms beyond repetitive sensory information from the hindlimbs driving spinal network excitability of the lumbosacral urogenital neural circuitry. Furthermore, the impact of exercise training on the upper urinary tract (kidney) underscores the health benefit of activity based training on the entire urinary system within the SCI population.
- Locomotor Training
- Copyright © 2015, American Journal of Physiology - Renal Physiology