Abstract
The roles of the two substructures of the striatum, i.e., caudate and
putamen, in voluntary motor control are less addressed. The present
functional magnetic resonance imaging (fMRI) study investigated the
neural correlates of motor control while participants were asked to
press with their right index finger, and to hold naturally, and then to
relax, and we focused on whether the caudate and putamen were involved
differently during the pressing, holding, and relaxation of the finger.
Only the bilateral caudates were activated in the holding process, i.e.,
sustaining of the muscle contraction, and only bilateral putamen were
activated in the relaxation process, along with subthalamus nucleus
(STN). However, both the caudate and putamen were activated in the
pressing process. We conclude that the two substructures of the
striatum, i.e., caudate and putamen, play different roles in motor
control; the caudate plays a more important role in muscle contraction,
while the putamen plays a more important role in muscle relaxation.
However, they cooperate together to accomplish a successful and smooth
movement, in line with the modulation role of the basal ganglia in motor
modulation.