Differences between motor execution and motor imagery of grasping movements in the motor cortical excitatory circuit

PeerJ

article

Hai-Jiang Meng¹  Yan-Ling Pi³  Ke Liu³  Na Cao¹  Yan-Qiu Wang¹  Yin Wu⁴  Jian Zhang¹ 

[1] School of Kinesiology, Shanghai University of Sport;School of Sports, Anqing Normal University;Shanghai Punan Hosptial of Pudong New District;School of Economics and Management, Shanghai University of Sport

关键词: Motor imagery;    Motor-evoked potential;    Motor execution;    Transcranial magnetic stimulation;    Motor cortex;    Intracortical inhibitory and excitatory circuits;   

DOI  :  10.7717/peerj.5588

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

Background Both motor imagery (MI) and motor execution (ME) can facilitate motor cortical excitability. Although cortical excitability is modulated by intracortical inhibitory and excitatory circuits in the human primary motor cortex, it is not clear which intracortical circuits determine the differences in corticospinal excitability between ME and MI. Methods We recruited 10 young healthy subjects aged 18−28 years (mean age: 22.1 ± 3.14 years; five women and five men) for this study. The experiment consisted of two sets of tasks involving grasp actions of the right hand: imagining and executing them. Corticospinal excitability and short-interval intracortical inhibition (SICI) were measured before the interventional protocol using transcranial magnetic stimulation (baseline), as well as at 0, 20, and 40 min (T0, T20, and T40) thereafter. Results Facilitation of corticospinal excitability was significantly greater after ME than after MI in the right abductor pollicis brevis (APB) at T0 and T20 (p < 0.01 for T0, and p < 0.05 for T20), but not in the first dorsal interosseous (FDI) muscle. On the other hand, no significant differences in SICI between ME and MI were found in the APB and FDI muscles. The facilitation of corticospinal excitability at T20 after MI correlated with the Movement Imagery Questionnaire (MIQ) scores for kinesthetic items (Rho = −0.646, p = 0.044) but did not correlate with the MIQ scores for visual items (Rho = −0.265, p = 0.458). Discussion The present results revealed significant differences between ME and MI on intracortical excitatory circuits of the human motor cortex, suggesting that cortical excitability differences between ME and MI may be attributed to the activation differences of the excitatory circuits in the primary motor cortex.

【 授权许可】

CC BY