臨床神経学

<シンポジウム(1)―9―3>小脳症状とは何か

小脳による運動制御機構

永雄 総一

独立行政法人・理化学研究所・脳科学総合研究センター・運動学習制御研究チーム〔〒351―0198 埼玉県和光市広沢2―1〕

Most of our motor skills are acquired through learning. Experiments of gain adaptation of ocular reflexes have consistently suggested that the memory of adaptation is initially formed in the cerebellar cortex, and is transferred to the cerebellar (vestibular) nuclei for consolidation to long-term memory after repetitions of training. We have recently developed a new system to evaluate the motor learning in human subjects using prism adaptation of hand reaching movement, by referring to the prism adaptation of dart throwing of Martin et al. (1996). In our system, the subject views the small target presented in the touch-panel screen, and touches it with his/her finger without direct visual feedback. After 15-30 trials of touching wearing prisms, an adaptation occurs in healthy subjects: they became able to touch the target correctly. Meanwhile, such an adaptation was impaired in patients of cerebellar disease. We have proposed a model of human prism adaptation that the memory of adaptation is initially encoded in the cerebellar cortex, and is later transferred to the cerebellar nuclei after repetitions of training. The memory in the cerebellar cortex may be formed and extinguished independently of the memory maintained in the cerebellar nuclei, and these two memories work cooperatively.
Full Text of this Article in Japanese PDF (252K)

(臨床神経, 52:994−996, 2012)
key words:小脳,運動学習,記憶痕跡の移動,随意運動制御,プリズム適応

(受付日:2012年5月23日)