Multielectrode evidence for spreading activity across the superior colliculus movement map.
Multielectrode evidence for spreading activity across the superior colliculus movement map.
复制标题
跨上丘运动图传播活动的多电极证据。
DOI：
10.1152/jn.2000.84.1.344
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发表时间：
2000
影响因子：
2.5
通讯作者：
Wurtz,RH
中科院分区：
文献类型：
--
作者：
Port,NL;Sommer,MA;Wurtz,RH
猴子的上级丘（SC）有地图的视觉输入和运动输出的表层和中间层，分别，和这些地图上的活动通常是相关的视觉刺激，只有在一个部分的视野和/或有限的范围内扫视眼球运动的刺激。然而，对于这些地图内的一些神经元，活动已被报道在扫视过程中从尾侧SC传播到喙侧SC。这种活动的传播是从SC运动图上不同部位的记录的平均值推断出来的，这些记录是在不同幅度的扫视期间，甚至是在不同的猴子中。在本实验中，SC活动同时记录在成对的神经元，以观察在个人扫视活动的传播。两个电极被定位沿着的头-尾轴的SC与一个比其他更尾部，和60个神经元对的运动场足够大，看到一个传播的活动进行了研究。在单个扫视期间，使用1）两个神经元的峰值放电之间的时间差，2）两个神经元的“中值激活时间”之间的差异，和3）使用互相关对齐两个放电模式所需的偏移，来比较两个神经元的相对放电时间。所有三种分析方法都给出了相当的结果。许多对神经元被激活的顺序在扫视的产生，和激活的顺序是最常见的尾侧到吻侧。并非在每对神经元中都观察到这种激活序列，但在所研究的神经元对样本中，这种扩散具有统计学意义。当我们比较神经元活动的时间扫视发作的时间，我们发现，尾部神经元活动更可能是在扫视之前，而吻侧神经元活动更可能是在扫视期间。这些结果表明，当单个对的神经元进行检查，在单扫视有证据表明，在猴子SC的活动的尾部到喙传播，他们证实了以前的推断，从观察平均神经元活动在多次扫视的活动传播。这一活动范围的功能贡献仍有待确定。
The monkey superior colliculus (SC) has maps for both visual input and movement output in the superficial and intermediate layers, respectively, and activity on these maps is generally related to visual stimuli only in one part of the visual field and/or to a restricted range of saccadic eye movements to those stimuli. For some neurons within these maps, however, activity has been reported to spread from the caudal SC to the rostral SC during the course of a saccade. This spread of activity was inferred from averages of recordings at different sites on the SC movement map during saccades of different amplitudes and even in different monkeys. In the present experiments, SC activity was recorded simultaneously in pairs of neurons to observe the spread of activity during individual saccades. Two electrodes were positioned along the rostral-caudal axis of the SC with one being more caudal than the other, and 60 neuron pairs whose movement fields were large enough to see a spread of activity were studied. During individual saccades, the relative time of discharge of the two neurons was compared using1) the time difference between peak discharge of the two neurons,2) the difference between the “median activation time” of the two neurons, and3) the shift required to align the two discharge patterns using cross-correlation. All three analysis methods gave comparable results. Many pairs of neurons were activated in sequence during saccade generation, and the order of activation was most frequently caudal to rostral. Such a sequence of activation was not observed in every neuron pair, but over the sample of neuron pairs studied, the spread was statistically significant. When we compared the time of neuronal activity to the time of saccade onset, we found that the caudal neuronal activity was more likely to be before the saccade, whereas the rostral neuronal activity was more likely to be during the saccade. These results demonstrate that when individual pairs of neurons are examined during single saccades there is evidence of a caudal to rostral spread of activity within the monkey SC, and they confirm the previous inferences of a spread of activity drawn from observations on averaged neuronal activity during multiple saccades. The functional contribution of this spread of activity remains to be determined.