Sensitivity of cortical movement representations to motor experience: evidence that skill learning but not strength training induces cortical reorganization

Behav Brain Res. 2001 Sep 14;123(2):133-41. doi: 10.1016/s0166-4328(01)00199-1.


The topography of forelimb movement representations within the rat motor cortex was examined following forelimb strength training. Adult male rats were allocated to either a Power Reaching, Control Reaching or Non-Reaching Condition. Power Reaching rats were trained to grasp and break progressively larger bundles of dried pasta strands with their preferred forelimb. Control Reaching animals were trained to break a single pasta strand and Non-Reaching animals were not trained. Power Reaching animals exhibited a progressive increase in the maximal size of the pasta bundle that could be retrieved during a 30-day training period. Kinematic analyses showed that this improvement was not due to a change in reaching strategy. Intracortical microelectrode stimulation was used to derive maps of forelimb movement representations within the motor cortex of all animals following training. In comparison to Non-Reaching animals, both Power Reaching and Control Reaching animals exhibited a significant increase in the proportion of motor cortex occupied by distal forelimb movement representations (wrist/digit) and a decrease in the proportion of proximal representations (elbow/shoulder). These results demonstrate that the development of skilled forelimb movements, but not increased forelimb strength, was associated with a reorganization of forelimb movement representations within motor cortex.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Brain Mapping
  • Forelimb / innervation*
  • Hand Strength / physiology
  • Isometric Contraction / physiology*
  • Male
  • Motor Cortex / physiology*
  • Motor Skills / physiology*
  • Neuronal Plasticity / physiology*
  • Psychomotor Performance / physiology*
  • Rats
  • Rats, Long-Evans