کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1907206 | 1046339 | 2010 | 8 صفحه PDF | دانلود رایگان |

BackgroundAging results in decreased neuromuscular function, which is likely associated with neurologic alterations. At present little is known regarding age-related changes in intracortical properties.MethodsIn this study we used transcranial magnetic stimulation (TMS) to measure intracortical facilitation (ICF), short- and long-interval intracortical inhibition (SICI and LICI), motor evoked potential amplitude, and silent period duration in young and older adults (21.4 ± 0.8 years and 70.9 ± 1.8 years). These variables were assessed from the flexor carpi radialis muscle of the non-dominant arm under resting conditions, and during a submaximal contraction (intensity 15% maximum strength).ResultsOlder adults exhibited increased SICI and LICI in comparison to young adults (SICI: 29.0 ± 9.2% vs. 46.2 ± 4.8% of unconditioned pulse; LICI: 6.5 ± 1.7% vs. 15.8 ± 3.3% of unconditioned pulse; P = 0.04), and less ICF under resting conditions (74.6 ± 8.7% vs. 104.9 ± 6.9% of unconditioned pulse; P = 0.02). These age-related differences disappeared during contraction, although the older adults did exhibit a longer silent period during contraction (112.5 ± 6.5 vs. 84.0 ± 3.9 ms; P < 0.01).ConclusionsCollectively, these findings suggest increased GABA mediated intracortical inhibition with age.
Journal: Experimental Gerontology - Volume 45, Issue 9, September 2010, Pages 671–678