Dynamic properties of recurrent inhibition in primary visual cortex: Contrast and orientation dependence of contextual effects
Dynamic properties of recurrent inhibition in primary visual cortex: Contrast and orientation dependence of contextual effects
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DOI：
10.1152/jn.2000.83.2.1019
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发表时间：
2000-02-01
影响因子：
2.5
通讯作者：
Sur, M
中科院分区：
文献类型：
--
作者：
Dragoi, V;Sur, M
初级视皮层复发性抑制的动态特性：语境效应的对比度和方向依赖性。神经生理学杂志。83：1019-1030，2000.初级视皮层（V1）神经回路的一个基本特征是棘神经元之间存在反复的兴奋性连接，光滑神经元之间存在反复的抑制性连接，以及兴奋性和抑制性神经元之间存在局部连接。我们模拟了V1中混合兴奋性和抑制性细胞群的动态行为，这些细胞群通过前馈丘脑皮层传入从经典感受野（感受野中心）接收输入，以及通过长距离皮层内连接从经典感受野（感受野周围）外部接收输入。一个违反直觉的结果是，当周围刺激相对于中心交叉取向时，取向细胞的反应可以被促进超过最佳水平，而当周围刺激是等取向时，取向细胞的反应被抑制。这种效应主要是由于局部回路内复发性抑制的变化。交叉取向的环绕刺激导致突触前抑制的减少和超最佳反应，而等取向的环绕刺激具有相反的效果。这种机制是用来解释的方向和对比度依赖的上下文交互在初级视觉皮层：对一个中心刺激的反应可以强烈抑制和超最佳促进作为一个功能的周围方向，这些影响减少刺激对比度降低。
Dynamic properties of recurrent inhibition in primary visual cortex: contrast and orientation dependence of contextual effects. J. Neurophysiol. 83: 1019-1030, 2000. A fundamental feature of neural circuitry in the primary visual cortex (V1) is the existence of recurrent excitatory connections between spiny neurons, recurrent inhibitory connections between smooth neurons, and local connections between excitatory and inhibitory neurons. We modeled the dynamic behavior of intermixed excitatory and inhibitory populations of cells in V1 that receive input from the classical receptive field (the receptive field center) through feedforward thalamocortical afferents, as well as input from outside the classical:receptive field (the receptive field surround) via long-range intracortical connections. A counterintuitive result is that the response of oriented cells can be facilitated beyond optimal levels when the surround stimulus is cross-oriented with respect to the center and suppressed when the surround stimulus is iso-oriented. This effect is primarily due to changes in recurrent inhibition within a local circuit. Cross-oriented surround stimulation leads to a reduction of presynaptic inhibition and a supraoptimal response, whereas iso-oriented surround stimulation has the opposite effect. This mechanism is used to explain the orientation and contrast dependence of contextual interactions in primary visual cortex: responses to a center stimulus can be both strongly suppressed and supraoptimally facilitated as a function of surround orientation, and these effects diminish as stimulus contrast decreases.