title: Information processing in the hemisphere of the cerebellar cortex for control of wrist movement.
abstract: A region of cerebellar lobules V and VI makes strong loop connections with the primary motor (M1) and premotor (PM) cortical areas and is assumed to play essential roles in limb motor control. To examine its functional role, we compared the activities of its input, intermediate, and output elements, i.e., mossy fibers (MFs), Golgi cells (GoCs), and Purkinje cells (PCs), in three monkeys performing wrist movements in two different forearm postures. The results revealed distinct steps of information processing. First, MF activities displayed temporal and directional properties that were remarkably similar to those of M1/PM neurons, suggesting that MFs relay near copies of outputs from these motor areas. Second, all GoCs had a stereotyped pattern of activity independent of movement direction or forearm posture. Instead, GoC activity resembled an average of all MF activities. Therefore, inhibitory GoCs appear to provide a filtering function that passes only prominently modulated MF inputs to granule cells. Third, PCs displayed highly complex spatiotemporal patterns of activity, with coordinate frames distinct from those of MF inputs and directional tuning that changed abruptly before movement onset. The complexity of PC activities may reflect rapidly changing properties of the peripheral motor apparatus during movement. Overall, the cerebellar cortex appears to transform a representation of outputs from M1/PM into different movement representations in a posture-dependent manner and could work as part of a forward model that predicts the state of the peripheral motor apparatus.
authors.affiliation: Movement Disorders Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan; Department of Neurophysiology, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan;
authors.forename: Saeka
authors.initials: S
authors.lastname: Tomatsu
authors.affiliation: Movement Disorders Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan;
authors.forename: Takahiro
authors.initials: T
authors.lastname: Ishikawa
authors.affiliation: Frontal Lobe Function Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan;
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Tsunoda
authors.affiliation: Movement Disorders Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan;
authors.forename: Jongho
authors.initials: J
authors.lastname: Lee
authors.affiliation: Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania; Center for the Neural Basis of Cognition, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania.
authors.forename: Donna S
authors.initials: DS
authors.lastname: Hoffman
authors.affiliation: Movement Disorders Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan; kakei-sj@igakuken.or.jp.
authors.forename: Shinji
authors.initials: S
authors.lastname: Kakei
mesh_terms: D000200:Action Potentials; D000818:Animals; D001696:Biomechanical Phenomena; D002525:Cerebellar Cortex / Q000502:physiology*; D005260:Female; D008253:Macaca mulatta; D008297:Male; D009068:Movement; D018482:Muscle, Skeletal / Q000294:innervation / Q000502:physiology; D009412:Nerve Fibers / Q000502:physiology*; D011689:Purkinje Cells / Q000502:physiology*; D014953:Wrist / Q000502:physiology*
keywords: Golgi cell; Purkinje cell; cerebellar cortex; monkey; mossy fiber; motor control