Mechanisms underlying cross-orientation suppression in cat visual cortex
Mechanisms underlying cross-orientation suppression in cat visual cortex
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DOI：
10.1038/nn1660
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发表时间：
2006-04-01
影响因子：
25
通讯作者：
Ferster, D
中科院分区：
文献类型：
--
作者：
Priebe, NJ;Ferster, D
在猫初级视皮层的简单细胞中，本身不引起反应的零取向刺激可以完全抑制对最佳取向刺激的尖峰反应。这种交叉取向抑制被解释为交叉取向抑制的证据：具有不同偏好取向的皮层细胞之间的突触抑制。然而，在简单细胞的细胞内记录中，我们发现交叉取向的刺激抑制而不是增强突触抑制，同时抑制突触兴奋。大部分的抑制兴奋可以解释膝状体中继细胞的行为：对比度饱和和整流中继细胞的反应，当应用到线性前馈模型，预测交叉取向抑制的调制（F1）成分的激发诱发简单的细胞。此外，我们发现简单细胞的尖峰输出的抑制几乎是其突触输入抑制的两倍。因此，交叉取向抑制，如取向选择性，强烈地通过阈值放大。
In simple cells of the cat primary visual cortex, null-oriented stimuli, which by themselves evoke no response, can completely suppress the spiking response to optimally oriented stimuli. This cross-orientation suppression has been interpreted as evidence for cross-orientation inhibition: synaptic inhibition among cortical cells with different preferred orientations. In intracellular recordings from simple cells, however, we found that cross-oriented stimuli suppressed, rather than enhanced, synaptic inhibition and, at the same time, suppressed synaptic excitation. Much of the suppression of excitation could be accounted for by the behavior of geniculate relay cells: contrast saturation and rectification in relay cell responses, when applied to a linear feed-forward model, predicted cross-orientation suppression of the modulation (F1) component of excitation evoked in simple cells. In addition, we found that the suppression of the spike output of simple cells was almost twice the suppression of their synaptic inputs. Thus, cross-orientation suppression, like orientation selectivity, is strongly amplified by threshold.