Effects of aging on the human motor cortical plasticity studied by paired associative stimulation

Clin Neurophysiol. 2010 Jan;121(1):90-3. doi: 10.1016/j.clinph.2009.07.048. Epub 2009 Nov 11.


Objective: To test whether the normal aging itself may change the cortical plasticity in human.

Methods: Motor-evoked potentials (MEPs) were measured from 48 right-handed healthy volunteers (age 21-79) before and after the paired associative stimulation (PAS), comprising a single electric stimulus to the right median nerve at wrist and subsequent transcranial magnetic stimulation (TMS) of the left primary motor cortex.

Results: The magnitude of MEP increased by PAS in the young and middle but not in the elderly and its change was negatively correlated with the age.

Conclusions: These results suggest that the human M1 shows age-dependent reduction of cortical plasticity.

Significance: The reduction of the M1 plasticity may be caused by the attenuated responsiveness of intracortical circuits in the M1 and/or disrupted sensorimotor integration within basal ganglia-thalamocortical loop.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aging / physiology*
  • Basal Ganglia / physiology
  • Electric Stimulation
  • Electromyography
  • Evoked Potentials, Motor / physiology*
  • Female
  • Humans
  • Male
  • Median Nerve / physiology*
  • Middle Aged
  • Motor Cortex / physiology*
  • Neuronal Plasticity / physiology*
  • Thalamus / physiology
  • Transcranial Magnetic Stimulation