title: Gating of sensory input at spinal and cortical levels during preparation and execution of voluntary movement.
abstract: All bodily movements stimulate peripheral receptors that activate neurons in the brain and spinal cord through afferent feedback. How these reafferent signals are processed within the CNS during movement is a key question in motor control. We investigated cutaneous sensory-evoked potentials in the spinal cord, primary somatosensory and motor cortex, and premotor cortex in monkeys performing an instructed delay task. Afferent inputs from cutaneous receptors were suppressed at several levels in a task-dependent manner. We found two types of suppression. First, suppression during active limb movement was observed in the spinal cord and all three cortical areas. This suppression was induced by both bottom-up and top-down gating mechanisms. Second, during preparation for upcoming movement, evoked responses were suppressed exclusively in the motor cortical areas and the magnitude of suppression was correlated with the reaction time of the subsequent movement. This suppression could be induced by a top-down gating mechanism to facilitate the preparation and execution of upcoming movement.
authors.affiliation: Department of Neurophysiology, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo 187-8502, Japan. seki@ncnp.go.jp
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Seki
authors.forename: Eberhard E
authors.initials: EE
authors.lastname: Fetz
mesh_terms: D000344:Afferent Pathways; D000704:Analysis of Variance; D000818:Animals; D001519:Behavior; D001696:Biomechanical Phenomena; D055592:Biophysical Phenomena; D002540:Cerebral Cortex / Q000502:physiology*; D004558:Electric Stimulation; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D056344:Executive Function / Q000502:physiology*; D008252:Macaca fascicularis; D008254:Macaca nemestrina; D009068:Movement / Q000502:physiology*; D011930:Reaction Time; D055139:Sensory Gating / Q000502:physiology*; D013116:Spinal Cord / Q000502:physiology*