TY - JOUR
T1 - Speed-dependent contribution of callosal pathways to ipsilateral movements
AU - Tazoe, Toshiki
AU - Perez, Monica A.
N1 - Copyright:
Copyright 2014 Elsevier B.V., All rights reserved.
PY - 2013
Y1 - 2013
N2 - Transcallosal inhibitory interactions between primary motor cortices are important to suppress unintended movements in a resting limb during voluntary activation of the contralateral limb. The functional contribution of transcallosal inhibition targeting the voluntary active limb remains unknown. Using transcranial magnetic stimulation, we examined transcallosal inhibition [by measuring interhemispheric inhibition (IHI) and the ipsilateral silent period (iSP)] in the preparatory and execution phases of isotonic slower self-paced and ballistic movements performed by the ipsilateral index finger into abduction and the elbow into flexion in intact humans. We demonstrate decreased IHI in the preparatory phase of self-paced and ballistic index finger and elbow movements compared to rest; the decrease in IHI was larger during ballistic than self-paced movements. In contrast, in the execution phase, IHI and the iSP increased during ballistic compared to self-paced movements. Transcallosal inhibition was negatively correlated with reaction times in the preparatory phase and positively correlated with movement amplitude in the execution phase. Together, our results demonstrate a widespread contribution of transcallosal inhibition to ipsilateral movements of different speeds with a functional role during rapid movements; at faster speeds, decreased transcallosal inhibition in the preparatory phase may contribute to start movements rapidly, while the increase in the execution phase may contribute to stop the movement.Weargue that transcallosal pathways enable signaling of the time of discrete behavioral events during ipsilateral movements, which is amplified by the speed of a movement.
AB - Transcallosal inhibitory interactions between primary motor cortices are important to suppress unintended movements in a resting limb during voluntary activation of the contralateral limb. The functional contribution of transcallosal inhibition targeting the voluntary active limb remains unknown. Using transcranial magnetic stimulation, we examined transcallosal inhibition [by measuring interhemispheric inhibition (IHI) and the ipsilateral silent period (iSP)] in the preparatory and execution phases of isotonic slower self-paced and ballistic movements performed by the ipsilateral index finger into abduction and the elbow into flexion in intact humans. We demonstrate decreased IHI in the preparatory phase of self-paced and ballistic index finger and elbow movements compared to rest; the decrease in IHI was larger during ballistic than self-paced movements. In contrast, in the execution phase, IHI and the iSP increased during ballistic compared to self-paced movements. Transcallosal inhibition was negatively correlated with reaction times in the preparatory phase and positively correlated with movement amplitude in the execution phase. Together, our results demonstrate a widespread contribution of transcallosal inhibition to ipsilateral movements of different speeds with a functional role during rapid movements; at faster speeds, decreased transcallosal inhibition in the preparatory phase may contribute to start movements rapidly, while the increase in the execution phase may contribute to stop the movement.Weargue that transcallosal pathways enable signaling of the time of discrete behavioral events during ipsilateral movements, which is amplified by the speed of a movement.
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U2 - 10.1523/JNEUROSCI.2638-13.2013
DO - 10.1523/JNEUROSCI.2638-13.2013
M3 - Article
C2 - 24107950
AN - SCOPUS:84885102699
VL - 33
SP - 16178
EP - 16188
JO - Journal of Neuroscience
JF - Journal of Neuroscience
SN - 0270-6474
IS - 41
ER -