部門公開セミナー

日 時 2012年09月14日 16:00~17:00
場 所 基生研 第一セミナー室
演 者 小島 奉子(よしこ) 先生(Department of Physiology and Biophysics, Washington National Primate Research Center, University of Washington)
演 題 Cerebellar influences on agonist and antagonist motoneuron activity during saccades
要 旨

Coordinated agonist and antagonist contractions are necessary for accurate movement. Impaired agonist-antagonist coordination could underlie movement dysmetria in cerebellar patients. Abnormal agonist-antagonist muscle contraction causes arm movement dysmetria. Despite the demonstrated role of the cerebellum in agonist-antagonist coordination, there is no description of the cerebellar influence on the activity of agonist and antagonist motoneurons during movement. Here I describe the cerebellum’s role in agonist and antagonist activity of neurons in the abducens nucleus (ABD) during horizontal saccades.

Saccades are well-suited to evaluating the influence of the cerebellum. The saccade-related parts of the cerebellar cortex, the oculomotor vermis (OMV) and nuclei, the caudal fastigial nucleus (cFN, also called the fastigial oculomotor region or FOR) are well-described. Damage to either area causes saccade dysmetria.

In this talk, I will describe the cFN influence on the agonist and antagonist ABD activity during horizontal saccades by characterizing how suppressing cFN activity changes the activity of single ABD neurons during saccades. We found that cFN activity normally decreases activity in all agonist ABD neurons during ipsiversive saccades. In most ABD neurons this decrease occurs during saccade deceleration. During contraversive saccade, cFN activity normally decreases activity in some antagonist ABD neurons. This decrease occurs during saccade acceleration in most of the affected neurons.

連絡先 橘 吉寿(生体システム研究部門 内線7774)