ROLE OF PRIMATE FLOCCULUS DURING RAPID BEHAVIORAL MODIFICATION OF VESTIBULOOCULAR REFLEX .1. PURKINJE-CELL ACTIVITY DURING VISUALLY GUIDED HORIZONTAL SMOOTH-PURSUIT EYE-MOVEMENTS AND PASSIVE HEAD ROTATION
ROLE OF PRIMATE FLOCCULUS DURING RAPID BEHAVIORAL MODIFICATION OF VESTIBULOOCULAR REFLEX .1. PURKINJE-CELL ACTIVITY DURING VISUALLY GUIDED HORIZONTAL SMOOTH-PURSUIT EYE-MOVEMENTS AND PASSIVE HEAD ROTATION
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DOI：
10.1152/jn.1978.41.3.733
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发表时间：
1978-01-01
影响因子：
2.5
通讯作者：
FUCHS, AF
中科院分区：
文献类型：
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作者：
LISBERGER, SG;FUCHS, AF
对警觉猴小叶中的124个浦肯野细胞（p细胞）进行了细胞外记录。定量分析了在眼球运动和被动头部旋转的不同组合下，p细胞的简单尖峰放电率。在正弦平滑眼动过程中，80%的p细胞在同侧眼动中表现出增加的放电率，20%在对侧眼动中表现出增加的放电率。在0.3 ~ 1.4 Hz频率范围内，放电速率调制与最大眼速成正比，并与最大眼速成相位。在三角波跟踪的稳态状态下，发射速率随眼速单调增加。由于放电速率与视错速度不相关，p细胞放电速率的1个分量与眼速度相关。在三角波跟踪的瞬态阶段，当目标运动方向的瞬时变化引起较大的视网膜误差速度时，40%的p细胞仅与眼速度有关。在p细胞中，60%的放电速率显示出过冲或过低，这表明与视网膜误差速度或眼睛加速度以及眼睛速度有关。在黑暗中头部旋转引起的前庭反射（VOR）期间，p细胞的放电速率仅被微弱调节。当猴子盯着一个和他一起旋转的目标来抑制VOR时。p细胞放电速率被深度调节。由于调制与最大头部速度成正比并同相，p细胞放电速率的另一个组成部分与头部速度有关。在36个被测试的p细胞中，35个在抑制VOR和平滑追踪眼动期间显示发射速率调制。p细胞在同侧头部旋转时达到峰值放电速率，在同侧眼睛平稳旋转时也达到峰值放电速率。种群对头速度和眼速度的平均敏感性相等。在同时激发眼速和头速的3种情况下，p细胞的放电速率可以通过眼速和头速的线性矢量相加来预测。在黑暗中，在VOR过程中p细胞放电速率的调制相对较弱，这可能是由相等但相反的头和眼速度分量的抵消造成的。在其他哺乳动物中也发现了小叶p细胞与脑干VOR通路中中间神经元的连接。在这些联系的背景下，p细胞的放电模式适合于促进金钱所要求的眼球运动。显然，小叶对于维持眼球的平滑运动很重要，这与在黑暗中头部旋转所引起的运动不同。眼速度分量可以表示在平滑追踪期间维持持续眼速度的干扰复制信号。
Extracellular recordings were obtained from 124 Purkinje cells (P-cells) in the flocculus of alert monkeys [Macaca mulatta]. P-cell simple spike-firing rate was analyzed quantitatively during various combinations of smooth-pursuit eye movement and passive head rotation. During sinusoidal smooth eye movements, 80% of the P-cells displayed increased firing rate during ipsilateral and 20% during contralateral eye movement. Over the frequency range 0.3-1.4 Hz, firing-rate modulation was proportional to and in phase with maximum eye velocity. During the steady state of triangle-wave tracking, firing rate increased monotonically as a function of eye velocity. Since firing rate was uncorrelated with retinal-error velocity, 1 component of P-cell firing rate was related to eye velocity. During the transient phase of triangle-wave tracking, when an instantaneous change in the direction of target movement caused a large retinal-error velocity, 40% of the P-cells were related only to eye velocity. Of the P-cells, 60% displayed an overshoot or undershoot in firing rate, indicating a relationship to either retinal-error velocity or eye acceleration and to eye velocity. During the vestibuloocular reflex (VOR), evoked by head rotation in the dark, P-cell firing rate was only weakly modulated. When the monkey suppressed the VOR by fixating a target that rotated with him. P-cell firing rate was deeply modulated. Since the modulation was proportional to and in phase with maximum head velocity, another component of P-cell firing rate was related to head velocity. Of 36 P-cells tested, 35 displayed firing-rate modulation during suppression of the VOR and smooth-pursuit eye movement. P-cells that reached peak firing rate during ipsilateral head rotation also reached peak firing rate during ipsilateral smooth eye rotation. Average population sensitivities to head velocity and eye velocity were equal. In 3 conditions in which eye and head velocity were elicited simultaneously, P-cell firing rate could be predicted by the linear, vector addition of the separate eye and head velocity components of firing rate. The relatively weak modulation of P-cell firing rate during the VOR in the dark could be accounted for by the cancellation of equal but opposite head and eye velocity components. The connections of flocculus P-cells to interneurons in the brain stem VOR pathways are established in other mammals. In the context of those connections, P-cell firing patterns were appropriate to facilitate the eye movements the moneky was required to make. Apparently the flocculus is important for sustaining any smooth eye movements that are different from those evoked by head rotation in the dark. The eye velocity component may represent an efference copy signal that sustains ongoing eye velocity during smooth pursuit.