Activity-based therapies to promote forelimb use after a cervical spinal cord injury

J Neurotrauma. 2009 Oct;26(10):1719-32. doi: 10.1089/neu.2008-0592.

Abstract

Significant interest exists in strategies for improving forelimb function following spinal cord injury. We investigated the effect of enriched housing combined with skilled training on the recovery of skilled and automatic forelimb function after a cervical spinal cord injury in adult rats. All animals were pretrained in skilled reaching, gridwalk crossing, and overground locomotion. Some received a cervical over-hemisection lesion at C4-5, interrupting the right side of the spinal cord and dorsal columns bilaterally, and were housed in standard housing alone or enriched environments with daily training. A subset of animals received rolipram to promote neuronal plasticity. Animals were tested weekly for 4 weeks to measure reaching, errors on the gridwalk, locomotion, and vertical exploration. Biotinylated dextran amine was injected into the cortex to label the corticospinal tract. Enriched environments/daily training significantly increased the number and success of left reaches compared to standard housing. Animals also made fewer errors on the gridwalk, a measure of coordinated forelimb function. However, there were no significant improvements in forelimb use during vertical exploration or locomotion. Likewise, rolipram did not improve any of the behaviors tested. Both enriched housing and rolipram increased plasticity of the corticospinal tract rostral to the lesion. These studies indicate that skilled training after a cervical spinal cord injury improves recovery of skilled forelimb use (reaching) and coordinated limb function (gridwalk) but does not improve automatic forelimb function (locomotion and vertical exploration). These studies suggest that rehabilitating forelimb function after spinal cord injury will require separate strategies for descending and segmental pathways.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biotin / analogs & derivatives
  • Cervical Vertebrae / injuries*
  • Dextrans
  • Disease Models, Animal
  • Environment, Controlled
  • Exercise Therapy / methods*
  • Exploratory Behavior / physiology
  • Female
  • Forelimb / innervation
  • Forelimb / physiopathology*
  • Gait Disorders, Neurologic / drug therapy
  • Gait Disorders, Neurologic / physiopathology
  • Gait Disorders, Neurologic / rehabilitation
  • Movement Disorders / drug therapy
  • Movement Disorders / physiopathology
  • Movement Disorders / rehabilitation
  • Neuronal Plasticity / drug effects
  • Neuronal Plasticity / physiology
  • Neuronal Tract-Tracers
  • Paralysis / drug therapy
  • Paralysis / physiopathology
  • Paralysis / rehabilitation*
  • Phosphodiesterase Inhibitors / pharmacology
  • Phosphodiesterase Inhibitors / therapeutic use
  • Physical Conditioning, Animal / physiology
  • Pyramidal Tracts / drug effects
  • Pyramidal Tracts / injuries
  • Pyramidal Tracts / physiopathology
  • Rats
  • Rats, Sprague-Dawley
  • Recovery of Function / drug effects
  • Recovery of Function / physiology
  • Rolipram / pharmacology
  • Rolipram / therapeutic use
  • Spinal Cord Injuries / drug therapy
  • Spinal Cord Injuries / physiopathology
  • Spinal Cord Injuries / rehabilitation*
  • Treatment Outcome

Substances

  • Dextrans
  • Neuronal Tract-Tracers
  • Phosphodiesterase Inhibitors
  • biotinylated dextran amine
  • Biotin
  • Rolipram