ROLE OF MONKEY MIDBRAIN NEAR-RESPONSE NEURONS IN PHORIA ADAPTATION
ROLE OF MONKEY MIDBRAIN NEAR-RESPONSE NEURONS IN PHORIA ADAPTATION
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DOI：
10.1152/jn.1992.67.6.1475
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发表时间：
1992-06-01
影响因子：
2.5
通讯作者：
LINDSEY, JW
中科院分区：
文献类型：
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作者：
MORLEY, JW;JUDGE, SJ;LINDSEY, JW
1.眼睛的调节和会聚的组织方式的一个显着特征是，尽管这两种反应通常是紧密耦合的，但通过棱镜进行短暂的双眼观察需要额外的会聚，这会导致两种反应之间的关系发生持续的、自适应的改变：单目观察给定距离处的目标时的聚散度偏向会聚方向。我们试图发现我们先前描述的猴子中脑中的近反应神经元在这种隐斜视适应中的作用。隐斜视适应是通过让两只猴子在模仿棱镜观察的条件下观察双眼立体目标来产生的，即，立体镜的反射镜被设置为需要比与在立体镜中看到的图像相同距离处的真实的目标相关联的反射镜更多的会聚。在适应前后，记录猴单眼观察不同距离目标时，位于眼神经核背侧和背外侧的57个近反应神经元的活动.比较一个神经元的反应，在正常的双眼观看的反应时，调节和聚散刺激是在冲突中允许我们区分24个神经元的行为，好像他们是专门相关的聚散反应，5个神经元的行为，好像他们是专门相关的调节反应，和12个神经元的发射是不是那么简单的反应。我们无法通过这种方法对剩余的16个近反应细胞进行分类。在隐斜视相关神经元中，当动物的隐斜视被适应时，放电频率和调节之间的关系没有改变，或者只有轻微的改变。放电率和聚散度之间的关系是不变的隐斜视适应只有一小部分的聚散度相关的神经元，表明大多数神经元不携带负责隐斜视适应的整个信号。另一方面，在大多数与聚散度相关的神经元中，隐斜视适应改变了放电频率与调节的关系，表明大多数神经元确实携带部分隐斜视适应信号.这意味着适应后观察到的聚散度增加是在一个以上的网站介导的。隐斜视适应信号的一部分是存在于中脑的vergence相关的神经元的水平，与信号的其余部分被添加后，大概在运动神经元。
1. One striking characteristic of the way in which accommodation and convergence of the eyes are organized is that although the two responses are usually tightly coupled, a brief period of binocular viewing through prisms that require extra convergence brings about a persistent, adaptive alteration in the relationship between the two responses: the vergence during monocular viewing of a target at a given distance is biased in a convergent direction. We sought to discover the role of the near-response neurons we have previously described in the monkey midbrain in such phoria adaptation.2. Phoria adaptation was produced in two monkeys by having them view binocularly stereoscopic targets under conditions that mimicked prism viewing, i.e., the mirrors of the stereoscope were set so as to require more convergence than that associated with a real target at the same distance as the images seen in the stereoscope. The activity of 57 near-response neurons located dorsally and dorsolaterally to the oculomotor nucleus was recorded before and after adaptation while the monkeys monocularly viewed targets at a range of distances.3. Comparison of a neuron's response in normal binocular viewing with the response when the accommodation and vergence stimuli were in conflict allowed us to distinguish 24 neurons that behaved as though they were related exclusively to the vergence response, 5 neurons that behaved as though they were exclusively related to the accommodation response, and 12 neurons whose firing was not so simply related to either response. We were unable to classify the remaining 16 near-response cells by this method.4. In accommodation-related neurons, the relationship between firing rate and accommodation did not alter, or only altered slightly, when the animal's phoria was adapted.5. The relationship between firing rate and vergence was unaltered by phoria adaptation in only a small proportion of vergence-related neurons, showing that most neurons do not carry the entire signal responsible for phoria adaptation. On the other hand, in the majority of vergence-related neurons the relationship between firing rate and accommodation was altered by phoria adaptation, showing that most neurons do carry part of the phoria adaptation signal.6. The implication is that the increase in vergence observed after adaptation is mediated at more than one site. A proportion of the phoria adaptation signal is present at the level of the midbrain vergence-related neurons, with the remainder of the signal being added later, presumably at the motoneurons.