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Cortical muscle control of spontaneous movements in human neonates
Author(s) -
Kanazawa Hoshinori,
Kawai Masahiko,
Kinai Takahiro,
Iwanaga Kougorou,
Mima Tatsuya,
Heike Toshio
Publication year - 2014
Publication title -
european journal of neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.346
H-Index - 206
eISSN - 1460-9568
pISSN - 0953-816X
DOI - 10.1111/ejn.12612
Subject(s) - electromyography , primary motor cortex , electroencephalography , neuroscience , motor cortex , physical medicine and rehabilitation , coherence (philosophical gambling strategy) , psychology , cortex (anatomy) , sensory system , somatosensory system , motor system , stimulation , medicine , anatomy , physics , quantum mechanics
Anatomical studies show the existence of corticomotor neuronal projections to the spinal cord before birth, but whether the primary motor cortex drives muscle activity in neonatal ‘spontaneous’ movements is unclear. To investigate this issue, we calculated corticomuscular coherence ( CMC ) and G ranger causality in human neonates. CMC is widely used as an index of functional connectivity between the primary motor cortex and limb muscles, and G ranger causality is used across many fields of science to detect the direction of coherence. To calculate CMC and G ranger causality, we used electroencephalography ( EEG ) to measure activity over the cortical region that governs leg muscles, and surface electromyography ( EMG ) over the right and left tibialis anterior muscles, in 15 healthy term and preterm neonates, during spontaneous movements without any external stimulation. We found that 17 leg muscles (10 right, seven left) in 12 neonates showed significant CMC , whose magnitude significantly correlated with postnatal age only in the beta frequency band. Further analysis revealed G ranger causal drive from EEG to EMG in 14 leg muscles. Our findings suggest that the primary motor cortex drives muscle activity when neonates move their limbs. Moreover, the positive correlation between CMC magnitude and postnatal age suggests that corticomuscular communication begins to develop during the neonatal stage. This process may facilitate sensory‐motor integration and activity‐dependent development.