Mapping Different Intra-Hemispheric Parietal-Motor Networks Using Twin Coil TMS

Brain Stimulation

Mark Hallett¹  Chi-Chao Chao²  Rainer Paine³  Anke Ninija Karabanov⁴ 

[1] Corresponding author. Danish Research Center for Magnetic Resonance, Department of MR, Section 340, Copenhagen University Hospital Hvidovre, Kettegaard Allé 30, DK-2650 Hvidovre, Denmark. Tel.: [phone].;Danish Research Center for Magnetic Resonance, Hvidovre Hospital, Hvidovre, Denmark;Department of Exercise and Sport Sciences, Copenhagen University, Copenhagen, Denmark;National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA;

关键词: Twin-coil TMS;    Intra-parietal sulcus;    Primary motor cortex;    Intra-hemispheric connectivity;   

DOI  :  

来源: DOAJ

【 摘 要 】

Background: Accumulating evidence suggests anatomical and functional differences in connectivity between the anterior and posterior parts of the inferior-parietal lobule (IPL) and the frontal motor areas. Objective/Hypothesis: This study investigates whether different intra-hemispheric parietal-motor interactions can be observed along the anterior–posterior axis of the IPL in the resting human brain. Methods: We use a twin coil transcranial magnetic stimulation technique to test intra-hemispheric interactions between three points adjacent to the intra-parietal sulcus (anterior, central, posterior) and the ipsilateral primary motor cortex (M1) at rest in both hemispheres. Results: We found that stimulation of the anterior IPL resulted in an inhibition of the ipsilateral M1 in both hemispheres. Stimulation of the central and posterior IPL resulted in a facilitatory effect on ipsilateral M1 in the left but not for the right hemisphere. Additionally we show that there is considerable inter-subject variability concerning the optimal parietal facilitatory and inhibitory position. Conclusions: The IPL has distinct inhibitory and facilitatory connections to the ipsilateral M1. Whereas inhibitory connections are observed in both hemispheres, facilitatory connections are asymmetric. These parietal-motor networks may represent the basis for the functional differences between these regions in reaching and grasping tasks and mirror the functional asymmetry observed in the motor system. From a practical point of view, we note that the inter-subject variability means that future TMS studies of the parietal area might consider a hot-spot localization similar to the procedures commonly used for M1.

【 授权许可】

Unknown