Evidence for existence of trunk-limb neural interaction in the corticospinal pathway

NEUROSCIENCE LETTERS

卷:668

Article

Sasaki, Atsushi¹  Milosevic, Matija¹  Sekiguchi, Hirofumi²  Nakazawa, Kimitaka¹ 

[1] Univ Tokyo, Grad Sch Arts & Sci, Dept Life Sci, Meguro Ku, 3-8-1 Komaba, Tokyo 1538902, Japan

[2] Jobu Univ, Fac Business & Informat Sci, Sports & Hlth Management Program, 634-1 Toyazukamachi, Gunma 3728588, Japan

关键词: Trunk;    Corticospinal excitability;    Motor evoked potentials;    Remote effect;    Trunk-limb interaction;   

DOI  :  10.1016/j.neulet.2018.01.011

来源: Elsevier

【 摘 要 】

In humans, trunk muscles have an essential role in postural control as well as walking. However, little is known about the mechanisms of interaction with different muscles, especially related to how trunk muscles interact with the limbs. Contraction of muscles can modulate the corticospinal excitability not only of the contracted muscle, but also of other muscles even in the remote segments of the body. However, remote effect mechanism has only been examined for inter-limb interactions. The aim of our current study was to test if there are trunk limb interactions in the corticospinal pathways. We examined corticospinal excitability of: (a) trunk muscles at rest when hands, legs and jaw muscles were contracted and; (b) hand, leg, and jaw muscles at rest when trunk muscles were contracted. We measured motor evoked potentials elicited using transcranial magnetic stimulation in the rectus abdominis, flexor digitorum superficialis, masseter, tibialis anterior muscles under the following experimental conditions: (1) participants remained relaxed (Rest); (2) during trunk contraction (Trunk); (3) during bilateral hand clenching (Hands); (4) during jaw clenching (Jaw); and (5) during bilateral ankle dorsiflexion (Legs). Each condition was performed at three different stimulation intensities and conditions were randomized between participants. We found that voluntary contraction of trunk muscle facilitated the corticospinal excitability of upper-limb and lower-limb muscles during rest state. Furthermore, voluntary contraction of upper-limb muscle also facilitated the corticospinal excitability of trunk muscles during rest state. Overall, these results suggest the existence of trunk-limb interaction in the corticospinal pathway, which is likely depended on proximity of the trunk and limb representation in the motor cortex.

【 授权许可】

Free