A subcortical oscillatory network contributes to recovery of hand dexterity after spinal cord injury

Brain. 2009 Mar;132(Pt 3):709-21. doi: 10.1093/brain/awn338. Epub 2009 Jan 20.


Recent studies have shown that after partial spinal-cord lesion at the mid-cervical segment, the remaining pathways compensate for restoring finger dexterity; however, how they control hand/arm muscles has remained unclear. To elucidate the changes in dynamic properties of neural circuits connecting the motor cortex and hand/arm muscles, we investigated the cortico- and inter-muscular couplings of activities throughout the recovery period after the spinal-cord lesion. Activities of antagonist muscle pairs showed co-activation and oscillated coherently at frequencies of 30-46 Hz (gamma-band) by 1-month post-lesion. Such gamma-band inter-muscular coupling was not observed pre-lesion, but emerged and was strengthened and distributed over a wide range of hand/arm muscles along with the recovery. Neither the beta-band (14-30 Hz) cortico-muscular coupling observed pre-lesion nor a gamma-band oscillation was observed in the motor cortex post-lesion. We propose that a subcortical oscillator commonly recruits hand/arm muscles, via remaining pathways such as reticulospinal and/or propriospinal tracts, independent of cortical oscillation, and contributes to functional recovery.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biological Clocks / physiology*
  • Cerebral Cortex / physiopathology
  • Electromyography / methods
  • Fingers / physiopathology
  • Hand / physiopathology*
  • Macaca mulatta
  • Male
  • Muscle, Skeletal / physiopathology
  • Neural Pathways / physiopathology
  • Psychomotor Performance / physiology
  • Recovery of Function / physiology*
  • Spinal Cord Injuries / pathology
  • Spinal Cord Injuries / physiopathology*