کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4325329 1613993 2012 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Electromyographic bursting following the cortical silent period induced by transcranial magnetic stimulation
موضوعات مرتبط
علوم زیستی و بیوفناوری علم عصب شناسی علوم اعصاب (عمومی)
پیش نمایش صفحه اول مقاله
Electromyographic bursting following the cortical silent period induced by transcranial magnetic stimulation
چکیده انگلیسی

In subjects performing voluntary background contraction, transcranial magnetic stimulation (TMS) induces an interruption of electromyographic (EMG) activity known as the silent period (SP). This is thought to be mediated through the action of inhibitory cortical neurons, in particular involving γ-aminobutyric acid type B (GABAB) receptors. In some studies of the SP, a post-SP increase in EMG activity has been reported but not described in detail. In the present study we have sought to determine the presence and persistence of late EMG bursting associated with the return of voluntary drive after the SP, and to characterize the relationship to background contraction level, stimulus intensity, and SP duration. TMS was delivered at 3 levels of intensity (120, 140 and 160% of active motor threshold) and during 3 levels of voluntary contraction of the first dorsal interosseous muscle (10, 30 and 50% of maximum contraction) in a pseudo-randomized order in 11 healthy participants. The SP was followed by a brief (~ 60 ms) burst of EMG up to 290 ± 42% of the pre-stimulus EMG level. Both SP duration and the amplitude of the EMG burst increased with TMS intensity (p < 0.001). Burst amplitude correlated with SP duration (r2 = 0.750; p = 0.003). We conclude that post-SP EMG bursting is a quantifiable phenomenon that depends on the strength of TMS and the duration of the SP. This bursting may correspond with the post inhibitory period of disinhibition that has recently been identified in human motor cortex.


► We investigate the return of EMG activity after the TMS-induced silent period (SP).
► EMG activity returns with a brief burst above pre-stimulus baseline level.
► The post-SP EMG burst depends on the strength of TMS and the duration of the SP.
► The EMG burst may be related to cortical disinhibition.
► Post-SP bursts may have clinical relevance for measuring inhibition and disinhibition.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Brain Research - Volume 1446, 29 March 2012, Pages 40–45
نویسندگان
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