AUTHOR=Kubota Shinji , Hirano Masato , Koizume Yoshiki , Tanabe Shigeo , Funase Kozo TITLE=Changes in the Spinal Neural Circuits are Dependent on the Movement Speed of the Visuomotor Task JOURNAL=Frontiers in Human Neuroscience VOLUME=9 YEAR=2015 URL=https://www.frontiersin.org/journals/human-neuroscience/articles/10.3389/fnhum.2015.00667 DOI=10.3389/fnhum.2015.00667 ISSN=1662-5161 ABSTRACT=
Previous studies have shown that spinal neural circuits are modulated by motor skill training. However, the effects of task movement speed on changes in spinal neural circuits have not been clarified. The aim of this research was to investigate whether spinal neural circuits were affected by task movement speed. Thirty-eight healthy subjects participated in this study. In experiment 1, the effects of task movement speed on the spinal neural circuits were examined. Eighteen subjects performed a visuomotor task involving ankle muscle slow (nine subjects) or fast (nine subjects) movement speed. Another nine subjects performed a non-visuomotor task (controls) in fast movement speed. The motor task training lasted for 20 min. The amounts of D1 inhibition and reciprocal Ia inhibition were measured using H-relfex condition-test paradigm and recorded before, and at 5, 15, and 30 min after the training session. In experiment 2, using transcranial magnetic stimulation (TMS), the effects of corticospinal descending inputs on the presynaptic inhibitory pathway were examined before and after performing either a visuomotor (eight subjects) or a control task (eight subjects). All measurements were taken under resting conditions. The amount of D1 inhibition increased after the visuomotor task irrespective of movement speed (