RT Journal Article
SR Electronic
T1 Somatomotor cortical representations are predicted by levels of short-interval intracortical inhibition
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2020.04.24.057331
DO 10.1101/2020.04.24.057331
A1 Hilmar P. Sigurdsson
A1 Katherine Molloy
A1 Stephen R. Jackson
YR 2020
UL http://biorxiv.org/content/early/2020/04/25/2020.04.24.057331.abstract
AB Transcranial magnetic stimulation (TMS) can be used to probe for the location of cortical somatomotor representations in humans. These somatomotor representations are dynamic and are perturbed following motor training, systematic intervention, and in disease. Evidence suggests that these representations are maintained by the inhibitory neurotransmitter gamma-Aminobutyric acid (GABA). In the current study, we quantified the location, outline, and variability of the first dorsal interosseous (FDI) hand muscle somatomotor representation using a novel rapid-acquisition TMS method in 14 healthy young volunteers. In addition, resting motor thresholds were measured using established protocols. TMS was also used to examine short-interval intracortical inhibition (SICI), which is thought to measure transiently activated cortical gamma-Aminobutyric acid (GABA) interneurons. Using stepwise regression, our results showed that the level of intracortical inhibition was a significant predictor of the FDI somatomotor representation suggesting that greater excitability of the hand area representation is possibly governed by greater activation of transient GABA interneurons.Competing Interest StatementThe authors have declared no competing interest.