title: [Cerebellum and eye movement control -- neuronal mechanisms of memory-based smooth-pursuit and their early clinical application].
abstract: Recent studies implicate the cerebellum in cognitive functions in addition to its well-established roles in motor control and learning. Using a memory-based smooth-pursuit task that separates visual working memory from motor preparation and execution, monkeys were trained to pursue (i.e., go) or not pursue (i.e., no-go), a cued direction, based on the working memory of visual motion-direction and a go/no-go instruction. Task-related neuronal activity was examined in cerebral and cerebellar major smooth-pursuit pathways. Different cerebral and cerebellar areas carried distinctly different signals during memory-based smooth-pursuit. In the cerebellum, prediction-related signals (visual working memory, pursuit selection and movement preparation) were represented in the vermal lobules VI-VII and caudal fastigial nucleus, whereas the floccular region (flocculus and ventral paraflocculus) contained predominantly execution-related signals. This task was applied to patients with cerebellar degeneration and idiopathic Parkinson's disease (PD). None of the PD patients tested exhibited impaired working memory of motion-direction and/or go/no-go selection, but they did show task-specific difficulty in generating an initial smooth-pursuit component, suggesting difficulty in smooth-pursuit preparation. In contrast, most cerebellar patients exhibited impaired visual working memory in addition to difficulty in preparing for and executing smooth-pursuit. These results suggest different roles for the basal ganglia and cerebellum in smooth-pursuit planning.
authors.affiliation: Clinical Brain Research Laboratory, Sapporo Yamanoue Hospital.
authors.forename: Kikuro
authors.initials: K
authors.lastname: Fukushima
authors.forename: Junko
authors.initials: J
authors.lastname: Fukushima
authors.forename: Norie
authors.initials: N
authors.lastname: Ito
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Takei
authors.forename: Kunihiro
authors.initials: K
authors.lastname: Ikeno
authors.forename: Peter M
authors.initials: PM
authors.lastname: Olley
authors.forename: Susumu
authors.initials: S
authors.lastname: Chiba
authors.forename: Nobuyoshi
authors.initials: N
authors.lastname: Kobayashi
authors.forename: Kiyoharu
authors.initials: K
authors.lastname: Inoue
authors.forename: Tateo
authors.initials: T
authors.lastname: Warabi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D002531:Cerebellum / Q000502:physiology*; D006801:Humans; D008570:Memory, Short-Term / Q000502:physiology*; D008875:Middle Aged; D010300:Parkinson Disease / Q000503:physiopathology; D011698:Pursuit, Smooth / Q000502:physiology*