Rewiring of hindlimb corticospinal neurons after spinal cord injury

Nat Neurosci. 2010 Jan;13(1):97-104. doi: 10.1038/nn.2448. Epub 2009 Dec 13.

Abstract

Little is known about the functional role of axotomized cortical neurons that survive spinal cord injury. Large thoracic spinal cord injuries in adult rats result in impairments of hindlimb function. Using retrograde tracers, we found that axotomized corticospinal axons from the hindlimb sensorimotor cortex sprouted in the cervical spinal cord. Mapping of these neurons revealed the emergence of a new forelimb corticospinal projection from the rostral part of the former hindlimb cortex. Voltage-sensitive dye (VSD) imaging and blood-oxygen-level-dependent functional magnetic resonance imaging (BOLD fMRI) revealed a stable expansion of the forelimb sensory map, covering in particular the former hindlimb cortex containing the rewired neurons. Therefore, axotomized hindlimb corticospinal neurons can be incorporated into the sensorimotor circuits of the unaffected forelimb.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Axotomy / methods
  • Behavior, Animal
  • Brain Mapping*
  • Cervical Vertebrae
  • Disease Models, Animal
  • Female
  • Fluorescent Dyes
  • Forelimb / physiopathology
  • Hindlimb / physiopathology*
  • Image Processing, Computer-Assisted / methods
  • Magnetic Resonance Imaging / methods
  • Membrane Potentials / physiology
  • Motor Cortex / blood supply
  • Motor Cortex / physiopathology
  • Nerve Regeneration / physiology*
  • Oxygen / blood
  • Pyramidal Tracts / blood supply
  • Pyramidal Tracts / pathology*
  • Pyrazoles
  • Rats
  • Rats, Inbred Lew
  • Spinal Cord Injuries / pathology*
  • Spinal Cord Injuries / physiopathology*
  • Statistics, Nonparametric
  • Thiazoles

Substances

  • Fluorescent Dyes
  • Pyrazoles
  • RH1691
  • Thiazoles
  • Oxygen