RT Journal Article
SR Electronic
T1 Goal-dependent tuning of muscle spindle receptors during movement preparation
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2020.03.06.981530
DO 10.1101/2020.03.06.981530
A1 Stylianos Papaioannou
A1 Michael Dimitriou
YR 2020
UL http://biorxiv.org/content/early/2020/03/08/2020.03.06.981530.abstract
AB Voluntary movements are believed to be advantageously prepared before they are executed, but the neural mechanisms at work have been unclear. For example, there are no overt changes in skeletal muscle activity due to movement preparation. Here, using a delayed-reach manual task, we demonstrate a decrease in the firing rate of human muscle afferents (primary spindles) when preparing stretch rather than shortening of the spindle-bearing muscle. In two additional experiments, arm perturbations during reach preparation revealed a congruent decrease of stretch reflex gains, including at spinal latencies for shoulder muscles that are not strongly pre-loaded. Our study shows that movement preparation can involve sensory elements of the peripheral nervous system. This goal-dependent tuning of antagonist proprioceptors may benefit voluntary movement through stretch reflex modulation. We suggest that central preparatory activity can also reflect sensory control, and preparatory tuning of muscle spindle mechanoreceptors is a component of planned reaching movements.