Expression of motor learning in the response of the primate vestibuloocular reflex pathway to electrical stimulation.
Expression of motor learning in the response of the primate vestibuloocular reflex pathway to electrical stimulation.
复制标题
灵长类前庭眼反射通路对电刺激的反应中运动学习的表达。
DOI：
10.1152/jn.1992.67.6.1493
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发表时间：
1992
影响因子：
2.5
通讯作者：
Lisberger,SG
中科院分区：
文献类型：
--
作者：
Broussard,DM;Bronte-Stewart,HM;Lisberger,SG
1.前庭眼反射（VOR）经历长期的适应性变化，在持续的视网膜图像运动的存在下，在头部转动。以前使用自然刺激的实验提供了证据，证明VOR是由平行的途径，包括一些在学习过程中被修改和一些没有。我们已经使用电刺激前庭迷路调查的时间特性的信号，通过修改的途径。2.将电极长期植入上级半规管、水平管或前庭，以电激活前庭传入神经。通过给猴子戴上放大或缩小视力的眼镜来诱导学习。在运动学习之前，期间和之后，我们测量了由迷路的电刺激引起的眼球运动以及VOR的增益，VOR的增益定义为在黑暗中自然前庭刺激期间的眼速除以头速。3.施加到迷路的脉冲序列导致眼睛从刺激侧移开，眼睛速度的初始快速变化随后是稳态平台。VOR增益的变化引起了高原期眼速的轨迹和幅度的巨大变化，这表明我们的刺激电极可以进入修改后的通路。4.一个单一的，短暂的电流脉冲施加到迷路诱发的眼睛运动，具有5 ms的潜伏期，并由眼速度的脉冲远离刺激的一侧，然后反弹到刺激的一侧。为了量化运动学习对这些眼球运动的影响，我们汇总了不同VOR增益的数据，并计算了刺激后每毫秒眼速和VOR增益之间关系的斜率。我们将斜率称为“修正指数”。“5.与诱发眼速度相比，修正指数需要更长的时间才能恢复到基线，并在眼速度反弹时显示出一个大的峰值。刺激电流的增加增加的幅度和持续时间的修改指数，并揭示了几个后来的高峰。这些观察结果表明，运动学习的充分表达需要激活多突触通路和招募初级前庭传入与更高的电刺激阈值。6.在眼速的初始偏转过程中，修正指数几乎总是正的，并且修正指数的第一次变化的潜伏期通常与诱发眼动的潜伏期相同。（400字处截断摘要）
1. The vestibuloocular reflex (VOR) undergoes long-term adaptive changes in the presence of persistent retinal image motion during head turns. Previous experiments using natural stimuli have provided evidence that the VOR is subserved by parallel pathways, including some that are modified during learning and some that are not. We have used electrical stimulation of the vestibular labyrinth to investigate the temporal properties of the signals that are transmitted through the modified pathways. 2. Electrodes were implanted chronically in the superior semi-circular canal, the horizontal canal, or the vestibule for electrical activation of the vestibular afferents. Learning was induced by fitting the monkeys with spectacles that magnified or miniaturized vision. Before, during, and after motor learning, we measured the eye movements evoked by electrical stimulation of the labyrinth as well as the gain of the VOR, defined as eye speed divided by head speed during natural vestibular stimulation in the dark. 3. Trains of pulses applied to the labyrinth caused the eyes to move away from the side of stimulation with an initial rapid change in eye velocity followed by a steady-state plateau. Changes in the gain of the VOR caused large changes in the trajectory and magnitude of eye velocity during the plateau, showing that our stimulating electrodes had access to the modified pathways. 4. A single, brief current pulse applied to the labyrinth evoked an eye movement that had a latency of 5 ms and consisted of a pulse of eye velocity away from the side of the stimulation followed by a rebound toward the side of stimulation. To quantify the effect of motor learning on these eye movements, we pooled the data across different VOR gains and computed the slope of the relationship between eye velocity and VOR gain at each millisecond after the stimulus. We refer to the slope as the "modification index." 5. In comparison with the evoked eye velocity, the modification index took longer to return to baseline and showed a large peak at the time of the rebound in eye velocity. Increases in stimulus current increased both the amplitude and the duration of the modification index and revealed several later peaks. These observations suggest that the full expression of motor learning requires activation of multisynaptic pathways and recruitment of primary vestibular afferents with higher thresholds for electrical stimulation. 6. The modification index was almost always positive during the initial deflection in eye velocity, and the latency of the first change in the modification index was usually the same as the latency of the evoked eye movement.(ABSTRACT TRUNCATED AT 400 WORDS)