Cerebellar control of saccade dynamics: contribution of the fastigial oculomotor region.
Cerebellar control of saccade dynamics: contribution of the fastigial oculomotor region.
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DOI：
10.1152/jn.01021.2014
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发表时间：
2015-05
影响因子：
2.5
通讯作者：
J. Quinet;Laurent Goffart
中科院分区：
文献类型：
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作者：
J. Quinet;Laurent Goffart
顶动眼区是中后小脑影响眼跳产生的输出。最近的失活研究报告的意见，建议参与其动力学（速度和持续时间）。在这项工作中，我们测试了这一假设在头部约束猴子与电微刺激技术。更具体地说，我们研究了持续时间，频率和电流的影响引起的眼跳的刺激，从中央（直向前）的位置。结果表明，同侧或对侧眼跳的幅度和动力学依赖于刺激参数。其水平分量的持续时间和幅度随着刺激的持续时间而增加，直到最大幅度。改变刺激频率主要改变它们的潜伏期和峰值速度（对于对侧扫视）。电流也影响扫视的度量和动力学：水平幅度和峰值速度随着强度增加，而潜伏期减少。在对侧扫视中观察到的峰值速度和潜伏期的变化是不相关的。最后，我们发现当刺激频率降低时，在诱发同侧扫视的部位可以诱发对侧扫视。然而，它们的发作不是随着刺激的发作而发生，而是随着刺激的偏移而发生。这些结果证实了这一假设，即顶投影对脑桥延髓网状结构（PMRF）参与转向扫视，而fastigiocollicular预测有助于双边控制的视觉固定。我们认为小脑对扫视产生的影响包括招募神经元和控制PMRF中活跃群体的大小。
The fastigial oculomotor region is the output by which the medioposterior cerebellum influences the generation of saccades. Recent inactivation studies reported observations suggesting an involvement in their dynamics (velocity and duration). In this work, we tested this hypothesis in the head-restrained monkey with the electrical microstimulation technique. More specifically, we studied the influence of duration, frequency, and current on the saccades elicited by fastigial stimulation and starting from a central (straight ahead) position. The results show ipsilateral or contralateral saccades whose amplitude and dynamics depend on the stimulation parameters. The duration and amplitude of their horizontal component increase with the duration of stimulation up to a maximum amplitude. Varying the stimulation frequency mostly changes their latency and the peak velocity (for contralateral saccades). Current also influences the metrics and dynamics of saccades: the horizontal amplitude and peak velocity increase with the intensity, whereas the latency decreases. The changes in peak velocity and in latency observed in contralateral saccades are not correlated. Finally, we discovered that contralateral saccades can be evoked at sites eliciting ipsilateral saccades when the stimulation frequency is reduced. However, their onset is timed not with the onset but with the offset of stimulation. These results corroborate the hypothesis that the fastigial projections toward the pontomedullary reticular formation (PMRF) participate in steering the saccade, whereas the fastigiocollicular projections contribute to the bilateral control of visual fixation. We propose that the cerebellar influence on saccade generation involves recruiting neurons and controlling the size of the active population in the PMRF.