Suppressive surrounds of receptive fields in monkey frontal eye field.
Suppressive surrounds of receptive fields in monkey frontal eye field.
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DOI：
10.1523/jneurosci.0864-12.2012
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发表时间：
2012-08-29
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影响因子：
--
通讯作者：
Wurtz RH
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文献类型：
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作者：
Cavanaugh J;Joiner WM;Wurtz RH
确定神经元如何参与视觉处理的一个关键步骤是确定其视觉感受野(RF)。在对清醒猕猴(Macaca Mulatta)额叶视场(FEF)神经元进行记录时，我们用小光点探测视野，发现兴奋性RFs从RF中心到外围强度递减。然而，呈现以RF为中心的不同直径的刺激显示了与先前确定的兴奋性RF重叠的抑制环境，并且平均减少了84%的反应。因此，在该重叠区域，刺激产生兴奋或抑制，取决于刺激。用环形刺激强烈刺激射频外周使我们能够量化这种影响。改进的高斯差分(DOG)模型独立地改变了中心和周围的激活，解释了重叠区域的非线性活动。我们的结果表明：1)除了兴奋和抑制机制的大小和强度外，在FEF中发现的抑制环境与V1中的基本相同；2)系统地分析FEF中的抑制环境对于正确解释对大的和/或周围刺激的反应从而理解刺激环境的影响是必不可少的；3)调节环境的相对强度明显改变神经元的反应，因此可能在视觉注意和刺激突显引起的神经元变化中发挥重要作用。
A critical step in determining how a neuron contributes to visual processing is determining its visual receptive field (RF). While recording from neurons in frontal eye field (FEF) of awake monkeys (Macaca mulatta), we probed the visual field with small spots of light and found excitatory RFs that decreased in strength from RF center to periphery. However, presenting stimuli with different diameters centered on the RF revealed suppressive surrounds that overlapped the previously determined excitatory RF, and reduced responses 84% on average. Consequently, in that overlap area, stimulation produced excitation or suppression, depending on the stimulus. Strong stimulation of the RF periphery with annular stimuli allowed us to quantify this effect. A modified Difference of Gaussians (DoG) model that independently varied center and surround activation accounted for the nonlinear activity in the overlap area. Our results suggest that: 1) the suppressive surrounds found in FEF are fundamentally the same as those in V1 except for the size and strength of excitatory and suppressive mechanisms, 2) methodically assaying suppressive surrounds in FEF is essential for correctly interpreting responses to large and/or peripheral stimuli and therefore understanding the effects of stimulus context, 3) regulating the relative strength of the surround clearly changes neuronal responses, and may therefore play a significant part in the neuronal changes resulting from visual attention and stimulus salience.