Bilateral cervical contusion spinal cord injury in rats

Exp Neurol. 2009 Nov;220(1):9-22. doi: 10.1016/j.expneurol.2009.06.012. Epub 2009 Jun 25.

Abstract

There is increasing motivation to develop clinically relevant experimental models for cervical SCI in rodents and techniques to assess deficits in forelimb function. Here we describe a bilateral cervical contusion model in rats. Female Sprague-Dawley rats received mild or moderate cervical contusion injuries (using the Infinite Horizons device) at C5, C6, or C7/8. Forelimb motor function was assessed using a grip strength meter (GSM); sensory function was assessed by the von Frey hair test; the integrity of the corticospinal tract (CST) was assessed by biotinylated dextran amine (BDA) tract tracing. Mild contusions caused primarily dorsal column (DC) and gray matter (GM) damage while moderate contusions produced additional damage to lateral and ventral tissue. Forelimb and hindlimb function was severely impaired immediately post-injury, but all rats regained the ability to use their hindlimbs for locomotion. Gripping ability was abolished immediately after injury but recovered partially, depending upon the spinal level and severity of the injury. Rats exhibited a loss of sensation in both fore- and hindlimbs that partially recovered, and did not exhibit allodynia. Tract tracing revealed that the main contingent of CST axons in the DC was completely interrupted in all but one animal whereas the dorsolateral CST (dlCST) was partially spared, and dlCST axons gave rise to axons that arborized in the GM caudal to the injury. Our data demonstrate that rats can survive significant bilateral cervical contusion injuries at or below C5 and that forepaw gripping function recovers after mild injuries even when the main component of CST axons in the dorsal column is completely interrupted.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Axotomy / methods
  • Biotin / analogs & derivatives
  • Cervical Vertebrae
  • Dextrans
  • Disease Models, Animal
  • Female
  • Forelimb / innervation
  • Forelimb / physiopathology
  • Functional Laterality / physiology
  • Growth Cones / physiology
  • Growth Cones / ultrastructure
  • Hand Strength / physiology
  • Lameness, Animal / etiology
  • Lameness, Animal / pathology
  • Lameness, Animal / physiopathology
  • Movement Disorders / etiology
  • Movement Disorders / pathology
  • Movement Disorders / physiopathology*
  • Muscle Strength Dynamometer
  • Nerve Regeneration / physiology
  • Neurologic Examination
  • Neuronal Plasticity / physiology
  • Physical Stimulation
  • Pyramidal Tracts / injuries
  • Pyramidal Tracts / pathology
  • Pyramidal Tracts / physiopathology
  • Rats
  • Rats, Sprague-Dawley
  • Recovery of Function / physiology
  • Sensation Disorders / etiology
  • Sensation Disorders / pathology
  • Sensation Disorders / physiopathology*
  • Spinal Cord Injuries / complications
  • Spinal Cord Injuries / pathology
  • Spinal Cord Injuries / physiopathology*
  • Staining and Labeling

Substances

  • Dextrans
  • biotinylated dextran amine
  • Biotin