Proper execution of voluntary movement requires a sensorimotor transformation based on the initial limb state. For example, successfully reaching to a stable target requires the recruitment of different muscle groups depending on limb position at movement initiation. To test if this transformation could occur at the spinal level, we stimulated the cervical spinal cord of anesthetized monkeys while systematically changing initial posture and examined the modulation of the twitch response induced in the upper limb muscles.Results suggest that excitability in the cervical spinal cord is affected by initial arm posture through spinal reflex pathways. This posture-dependency of spinal motor output could affect voluntary arm movement by adjusting descending motor commands relative to the initial arm posture.
Research Area “Decoding and Controlling Brain Information”
Research Theme “The role of reference signal for generating volitional muscle activities”
H.Yaguchi, T.Takei, D.Kowalski, T.Suzuki, K.Mabuchi, and K.Seki. “Modulation of Spinal Motor Output by Initial Arm Postures in Anesthetized Monkeys”. Journal of Neuroscience, 35 (17):6937-6945, Published online 29 April 2015, doi: 10.1523/JNEUROSCI.3846-14.2015.
Kazuhiko SEKI, Ph.D.
Director, Department of neurophysiology, National institute of Neuroscience, NCNP
Koji Matsuo, Tetsu Kawaguchi, and Hideaki Inada
Life Innovation Group, Department of Innovation Research, JST