Similarity of superior colliculus involvement in microsaccade and saccade generation
Similarity of superior colliculus involvement in microsaccade and saccade generation
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DOI：
10.1152/jn.01125.2011
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发表时间：
2012-04-01
影响因子：
2.5
通讯作者：
Krauzlis, Richard J.
中科院分区：
文献类型：
--
作者：
Hafed, Ziad M.;Krauzlis, Richard J.
哈菲德·ZM，克劳兹利斯·RJ。上丘参与微眼跳和眼跳生成的相似性。 J Neurophysiol 107: 1904-1916, 2012。首次发表于 2012 年 1 月 11 日； doi: 10.1152/jn.01125.2011.-微眼跳或小注视眼跳的特征及其对视觉功能的影响已被广泛研究。然而，人们对产生这些运动的详细机制知之甚少。我们最近发现上丘（SC）是一种参与眼跳生成的中脑结构，也在微眼跳生成中发挥作用。在这里，我们将 SC 中与微扫视相关的神经元活动动态与在该结构中观察到的与较大随意扫视相关的神经元活动动态进行了比较。我们发现 SC 中与微扫视相关的活动的特点是，在微扫视开始前 100 毫秒左右开始，放电频率逐渐增加，运动开始后神经元放电达到峰值，随后放电频率逐渐降低，直到运动开始后 100 毫秒左右。这些特性与扫视相关的 SC 神经元相同，记录自同一只猴子，但更喜欢较大的眼球运动，这表明在 SC 水平上，微扫视的神经元控制与较大的随意扫视相似。我们还发现，表现出微扫视相关活动的神经元通常也表现出类似方向的稍大运动的扫视相关活动，这表明 SC 中的空间表征在幅度和方向上具有连续性，直至最小的运动。我们的结果表明，控制微扫视的机制可能与控制较大扫视的机制基本相同，从而为这些眼球运动的功能作用及其对感觉和感觉运动过程的可能影响提供了新的线索。
Hafed ZM, Krauzlis RJ. Similarity of superior colliculus involvement in microsaccade and saccade generation. J Neurophysiol 107: 1904-1916, 2012. First published January 11, 2012; doi: 10.1152/jn.01125.2011.-The characteristics of microsaccades, or small fixational saccades, and their influence on visual function have been studied extensively. However, the detailed mechanisms for generating these movements are less understood. We recently found that the superior colliculus (SC), a midbrain structure involved in saccade generation, also plays a role in microsaccade generation. Here we compared the dynamics of neuronal activity in the SC associated with microsaccades to those observed in this structure in association with larger voluntary saccades. We found that microsaccade-related activity in the SC is characterized by a gradual increase in firing rate starting similar to 100 ms prior to microsaccade onset, a peak of neuronal discharge just after movement onset, and a subsequent gradual decrease in firing rate until similar to 100 ms after movement onset. These properties were shared with saccade-related SC neurons, recorded from the same monkeys but preferring larger eye movements, suggesting that at the level of the SC the neuronal control of microsaccades is similar to that for larger voluntary saccades. We also found that neurons exhibiting microsaccade-related activity often also exhibited saccade-related activity for slightly larger movements of similar direction, suggesting a continuity of the spatial representation in the SC, in both amplitude and direction, down to the smallest movements. Our results indicate that the mechanisms controlling microsaccades may be fundamentally the same as those for larger saccades, and thus shed new light on the functional role of these eye movements and their possible influence on sensory and sensory-motor processes.