Modulation of the Direction and Magnitude of Hebbian Plasticity in Human Motor Cortex by Stimulus Intensity and Concurrent Inhibition

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• 作者：R.F.H. Cash^a ; ^b ; ^c ; G. Jegatheeswaran^a ; ^b ; Z. Ni^a ; ^b ; R. Chen^a ; ^b ; ^{Robert.Chen@uhn.ca}
• 关键词：Transcranial magnetic stimulation ; Paired associative stimulation ; Plasticity ; Intensity ; Short latency afferent inhibition ; Motor cortex ; Inhibition
• 刊名：Brain Stimulation
• 出版年：2017
• 出版时间：January-February 2017
• 年：2017
• 卷：10
• 期：1
• 页码：83-90
• 全文大小：420 K
• 卷排序：10

文摘

PAS plastic effects were inhibited by GABAA mediated inhibitory input known as short latency afferent inhibition (SAI). Inter-individual differences in SAI contributed to the variability of PAS effects. The magnitude and direction of plastic effects were modulated by TMS intensity, and an anti-Hebbian reversal of plastic effects was achieved at subthreshold intensity. The findings are in agreement with cellular studies showing that the magnitude and direction of Hebbian plastic effects are modulated by the level of neural activation. The identification of predictors of plasticity (such as SAI) and factors that can enhance plasticity induction (higher TMS intensity) is highly valuable if these protocols are to be applied in clinical populations. The modulation of short interval intracortical inhibition and facilitation (SICI, SICF) in the presence of SAI did not appear to relate to the magnitude of PAS effects.