Structural and functional regeneration after spinal cord injury in the weakly electric teleost fish, Apteronotus leptorhynchus

J Comp Physiol A Neuroethol Sens Neural Behav Physiol. 2009 Jul;195(7):699-714. doi: 10.1007/s00359-009-0445-4. Epub 2009 May 10.


In contrast to mammals, teleost fish exhibit an enormous potential to regenerate adult spinal cord tissue after injury. However, the mechanisms mediating this ability are largely unknown. Here, we analyzed the major processes underlying structural and functional regeneration after amputation of the caudal portion of the spinal cord in Apteronotus leptorhynchus, a weakly electric teleost. After a transient wave of apoptotic cell death, cell proliferation started to increase 5 days after the lesion and persisted at high levels for at least 50 days. New cells differentiated into neurons, glia, and ependymal cells. Retrograde tract tracing revealed axonal re-growth and innervation of the regenerate. Functional regeneration was demonstrated by recovery of the amplitude of the electric organ discharge, a behavior generated by spinal motoneurons. Computer simulations indicated that the observed rates of apoptotic cell death and cell proliferation can adequately explain the re-growth of the spinal cord.

MeSH terms

  • Animals
  • Apoptosis
  • Axons / physiology
  • Cell Differentiation
  • Cell Division
  • Computer Simulation
  • DNA Replication
  • Electric Organ / physiology
  • Female
  • Glial Fibrillary Acidic Protein / analysis
  • Gymnotiformes / injuries
  • Gymnotiformes / physiology*
  • Male
  • Models, Neurological
  • Motor Neurons / physiology
  • Nerve Regeneration / physiology*
  • S100 Proteins / analysis
  • Species Specificity
  • Spinal Cord Injuries / physiopathology*
  • Video Recording


  • Glial Fibrillary Acidic Protein
  • S100 Proteins