Dynamic intra- and interhemispheric interactions during unilateral and bilateral hand movements assessed with fMRI and DCM

Any motor action results from a dynamic interplay of various brain regions involved in different aspects of movement preparation and execution. Establishing a reliable model of how these areas interact is crucial for a better understanding of the mechanisms underlying motor function in both healthy...

Full description

Saved in:
Bibliographic Details
Published in:NeuroImage (Orlando, Fla.) Fla.), 2008-07, Vol.41 (4), p.1382-1394
Main Authors: Grefkes, Christian, Eickhoff, Simon B., Nowak, Dennis A., Dafotakis, Manuel, Fink, Gereon R.
Format: Article
Language:English
Subjects:
Adult
Bayes Theorem
Brain
Connectivity
DCM, fMRI
Female
Functional Laterality - physiology
Hand - innervation
Hand - physiology
Humans
Image Processing, Computer-Assisted
Magnetic Resonance Imaging
Male
Medical imaging
Middle Aged
Models, Neurological
Motor Cortex - physiology
Motor system
Movement - physiology
Nerve Net - physiology
Psychomotor Performance - physiology
SMA
Studies
Visual Cortex - physiology
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Any motor action results from a dynamic interplay of various brain regions involved in different aspects of movement preparation and execution. Establishing a reliable model of how these areas interact is crucial for a better understanding of the mechanisms underlying motor function in both healthy subjects and patients. We used fMRI and dynamic causal modeling to reveal the specific excitatory and inhibitory influences within the human motor system for the generation of voluntary hand movements. We found an intrinsic balance of excitatory and inhibitory couplings among core motor regions within and across hemispheres. Neural coupling within this network was specifically modulated upon uni- and bimanual movements. During unimanual movements, connectivity towards the contralateral primary motor cortex was enhanced while neural coupling towards ipsilateral motor areas was reduced by both transcallosal inhibition and top-down modulation. Bimanual hand movements were associated with a symmetric facilitation of neural activity mediated by both increased intrahemispheric connectivity and enhanced transcallosal coupling of SMA and M1. The data suggest that especially the supplementary motor area represents a key structure promoting or suppressing activity in the cortical motor network driving uni- and bilateral hand movements. Our data demonstrate that fMRI in combination with DCM allows insights into intrinsic properties of the human motor system and task-dependent modulations thereof.
ISSN:1053-8119
1095-9572
DOI:10.1016/j.neuroimage.2008.03.048