Role of primate medial vestibular nucleus in long-term adaptive plasticity of vestibuloocular reflex.
Role of primate medial vestibular nucleus in long-term adaptive plasticity of vestibuloocular reflex.
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灵长类内侧前庭核在前庭眼反射长期适应性可塑性中的作用。
DOI：
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发表时间：
1980
影响因子：
2.5
通讯作者：
F. A. Miles
中科院分区：
文献类型：
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作者：
S. Lisberger;F. A. Miles
1. 在警觉猴子的内侧前庭核（MVN）中记录了 1530 个细胞，这些猴子的前庭眼反射（VOR）已经适应了两种眼镜中的一种。 “高增益”样本是从佩戴 2.0 倍伸缩眼镜的猴子身上记录的；黑暗中 VOR 的增益（眼速除以头速）大于 1.5。 “低增益”样本是从戴着护目镜的猴子身上记录下来的，这些护目镜提供的视野相对于自由转动的头部是固定的； VOR的增益小于0.4。 2. 显示与施加的头部速度相关的放电速率调节的细胞分为四类：纯前庭 (10)、前庭加扫视 (10)、前庭加位置 (10) 和前庭加头部/身体 (24)。对头部速度的敏感度是通过对水平面内正弦 0.4 Hz 全身振荡的平均响应来测量的。几乎所有在同侧头部旋转期间放电增加的细胞（98%）都接收来自水平半规管的输入。相反，82% 的细胞在对侧头部旋转期间放电增加，接收来自垂直管的输入。 3.任何细胞类型的高增益和低增益样本之间的静息放电率、相移或对头部速度的敏感性没有统计学上的显着差异。尽管如此，在所有功能定义的细胞组中都存在明显的一致趋势，即高增益样本的灵敏度高出约 20%。然而，与 VOR 增益的四倍差异相比，这个差异很小。 4. 对单个细胞的反应特性的详细审查表明，敏感性的微小差异反映了分布在整个群体中的微小变化，而不是小群体内的大的和潜在的显着变化。 5. 我们的数据表明，VOR 增益的大的适应性变化仅伴随前庭灵敏度的微小变化，并且 MVN 中细胞的相移或静息放电率没有变化。前庭敏感性的巨大变化仍然有可能发生在我们未采样的细胞或我们无法识别的亚组中。我们认为这是不可能的，VOR 可塑性的主要变化发生在 VOR 通路中第一个中央突触之后。
1. Fifteen hundred and thirty cells were recorded in the medial vestibular nucleus (MVN) of alert monkeys whose vestibuloocular reflex (VOR) had been adapted to one of two kinds of spectacles. The "high-gain" sample was recorded from monkeys that had worn 2.0 x telescopic spectacles; the gain of the VOR in the dark (eye velocity divided by head velocity) was greater than 1.5. The "low-gain" sample was recorded from monkeys that had worn goggles providing a visual field that was fixed with respect to the freely turning head; the gain of the VOR was less than 0.4. 2. Cells showing modulation of firing rate related to imposed head velocity were grouped into four categories: pure vestibular (10), vestibular-plus-saccade (10), vestibular-plus-position (10), and vestibular-plus-head/body (24). Sensitivity to head velocity was measured from averaged responses to sinusoidal, 0.4-Hz whole-body oscillation in the horizontal plane. Almost all cells (98%) having increased firing during ipsilateral head rotation received inputs from the horizontal semicircular canals. Conversely, 82% of cells having increased firing during contralateral head rotation received inputs from the vertical canals. 3. There were no statistically significant differences in resting discharge rate, phase shift, or sensitivity to head velocity between the high- and low-gain samples of any of the cell types. Nonetheless, there was a consistent tendency, evident in all the functionally defined cell groups, for the sensitivity to be about 20% greater in the high-gain samples. However, this difference is small by comparison with the fourfold difference in VOR gain. 4. Detailed scrutiny of the response properties of individual cells suggested that the small differences in sensitivity reflect small changes distributed throughout the population, rather than large and potentially significant changes within a small sub-population. 5. Our data indicate that large, adaptive changes in the gain of the VOR are accompanied by only minor changes in the vestibular sensitivity and no changes in the phase shift or resting discharge rates of cells in the MVN. It remains possible that large changes in vestibular sensitivity occurred in cells we did not sample or in subgroups we could not identify. We argue that this is unlikely and that the major changes underlying VOR plasticity occur after the first central synapse in the VOR pathways.