The impact of brief exposure to high contrast on the contrast response of neurons in primate lateral geniculate nucleus
The impact of brief exposure to high contrast on the contrast response of neurons in primate lateral geniculate nucleus
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DOI：
10.1152/jn.00943.2010
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发表时间：
2011-09-01
影响因子：
2.5
通讯作者：
Solomon, Samuel G.
中科院分区：
文献类型：
--
作者：
Camp, Aaron J.;Cheong, Soon K.;Solomon, Samuel G.
Camp AJ、Cheong SK、Tailby C、所罗门 SG。短暂暴露于高对比度对灵长类外侧膝状核神经元对比度反应的影响。 《神经生理学杂志》106：1310-1321，2011 年。首次发表于 2011 年 6 月 8 日； doi:10.1152/jn.00943.2010.-长时间暴露于有效刺激通常会降低视觉通路早期神经元的敏感性。然而，眼睛和头部的运动会导致视网膜图像的频繁变化，而且目前尚不清楚暴露于简短的演示是否会产生类似的脱敏作用。为了解决这个问题，我们对麻醉狨猴（一种新世界灵长类动物）的外侧膝状核中的单个神经元进行了细胞外记录。我们测量了在高对比度漂移光栅、固定光栅或空白屏幕下暴露 0.5 秒之前和之后漂移光栅的对比度响应。先前暴露于漂移光栅会降低大细胞通路中细胞的对比敏感度，平均降低 23%；当适应刺激和测试刺激相隔 0.4 秒时，这种减少仍然很强烈。暴露于首选空间相位的固定光栅不会改变对比度响应；暴露于相反的空间相位确实如此。简短的适配器均不会降低细小细胞的敏感性。我们得出的结论是，短暂的高对比度时期（例如正常注视期间预期发生的时期）足以降低大细胞通路细胞的敏感性。
Camp AJ, Cheong SK, Tailby C, Solomon SG. The impact of brief exposure to high contrast on the contrast response of neurons in primate lateral geniculate nucleus. J Neurophysiol 106: 1310-1321, 2011. First published June 8, 2011; doi:10.1152/jn.00943.2010.-Prolonged exposure to an effective stimulus generally reduces the sensitivity of neurons early in the visual pathway. Yet eye and head movements bring about frequent changes in the retinal image, and it is less clear that exposure to brief presentations will produce similar desensitization. To address this, we made extracellular recordings from single neurons in the lateral geniculate nucleus of anesthetized marmosets, a New World primate. We measured the contrast response for drifting gratings before and after 0.5-s exposure to a high-contrast drifting grating, a stationary grating, or a blank screen. Prior exposure to the drifting grating reduced the contrast sensitivity of cells in the magnocellular pathway, on average by 23%; this reduction remained strong when the adapting and test stimuli were separated by 0.4 s. Exposure to a stationary grating of the preferred spatial phase did not change the contrast response; exposure to the opposite spatial phase did. None of the brief adaptors reduced the sensitivity of parvocellular cells. We conclude that brief periods of high contrast, such as those that would be expected to occur during a normal visual fixation, are sufficient to reduce the sensitivity of magnocellular-pathway cells.