title: Three-dimensional tuning profile of motor cortical activity during arm movements.
abstract: The neural firing activity in the primary motor cortex was modulated to the direction of hand movement. In contradiction to previous reports, a recent study found a non-uniform distribution of preferred directions of neurons while monkeys made center-out reaching movements in a horizontal plane. To re-examine the distribution of preferred directions in three-dimensional space, we recorded the activity of 117 arm-related neurons in the primary motor cortex and electromyographic signals of shoulder and upper arm muscles of a monkey while it performed center-out reaching movements towards 26 target points placed on a sphere-shaped workspace. We found that the distribution of preferred directions of neurons was non-uniform and that it was correlated to muscle activity and arm joint rotations.
authors.affiliation: Okayama University Medical School, Faculty of Health Sciences, 2-5-1 Shikata-cho, Okayama, 700-8558 Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Mitsuda
authors.forename: Paolo
authors.initials: P
authors.lastname: Onorati
mesh_terms: D000818:Animals; D001132:Arm / Q000502:physiology*; D004576:Electromyography / Q000379:methods / Q000706:statistics & numerical data; D005260:Female; D008253:Macaca mulatta; D009044:Motor Cortex / Q000502:physiology*; D009068:Movement / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology; D009474:Neurons / Q000502:physiology