Corticomotor excitability and plasticity following complex visuomotor training in young and old adults.

Previous studies with transcranial magnetic stimulation (TMS) have shown that advancing age may influence plasticity induction in human motor cortex (M1), but these changes have been assessed with TMS-induced paradigms or simple motor tasks. The aim of this study was to examine changes in corticospinal excitability and intracortical inhibition as markers of corticomotor plasticity following complex motor training in young and old adults. Electromyographic recordings were obtained from the right first dorsal interosseous (FDI) muscle of 16 young (20-35 years) and 16 older (aged 60-75 years) adults before and after motor skill training. Motor training consisted of three 6-minute blocks of a complex visuomotor task that required matching the metacarpophalangeal (MCP) joint angle of the index finger using abduction-adduction movements. Single- and paired-pulse TMS over the left M1 was used to assess changes in right FDI motor-evoked potentials (MEPs) and short-interval intracortical inhibition (SICI) before and after each training block. Visuomotor tracking performance was diminished in old compared with young adults throughout training. However, improvement in tracking error was similar for young and old adults (7-24% increase in each training block). For young and old adults, motor training increased FDI MEP amplitude (≥ 20%) and reduced the magnitude of SICI (≥ 19%) after each visuomotor training block, reflecting use-dependent plasticity. However, no difference in corticomotor plasticity (change in MEP or SICI) was observed between young and old adults. Further studies are needed to identify the experimental or behavioral factors that might contribute to the maintenance of corticomotor plasticity in older adults.

Cirillo J ，Todd G ，Semmler JG 《-》

Corticomotor plasticity and learning of a ballistic thumb training task are diminished in older adults.

Rogasch NC ，Dartnall TJ ，Cirillo J ，Nordstrom MA ，Semmler JG ... -  《-》

Functional plasticity of surround inhibition in the motor cortex during single finger contraction training.

Sugawara K ，Tanabe S ，Higashi T ，Suzuki T ，Tsurumi T ，Kasai T ... -  《-》

Hemispheric differences in use-dependent corticomotor plasticity in young and old adults.

Cirillo J ，Rogasch NC ，Semmler JG 《-》

Further evidence for excitability changes in human primary motor cortex during ipsilateral voluntary contractions.

Liang N ，Murakami T ，Funase K ，Narita T ，Kasai T ... -  《NEUROSCIENCE LETTERS》