Global inhibition and stimulus competition in the owl optic tectum.
Global inhibition and stimulus competition in the owl optic tectum.
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DOI：
10.1523/jneurosci.3740-09.2010
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发表时间：
2010-02-03
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影响因子：
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通讯作者：
Knudsen EI
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文献类型：
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作者：
Mysore SP;Asadollahi A;Knudsen EI
凝视和空间注意的刺激选择涉及跨感觉模态和跨所有空间的刺激之间的竞争。我们证明，这种跨模态的，全球性的竞争发生在中间和深层的视顶盖，已知的结构是参与凝视控制和注意。位于神经元感受野（RF）之外的任何地方的各种视觉或听觉刺激被证明可以抑制或完全消除对位于一氧化二氮镇静猫头鹰RF内的视觉刺激的反应。这种刺激竞争的基本机制是全局性的、分裂性的抑制。与经典的抑制性环绕的效果不同，它随着与RF中心的距离而减小，并形成对单个刺激的神经元反应，全局抑制作用于整个空间，并主要在多个刺激的背景下调节反应。虽然这种全球抑制的来源是未知的，我们的数据表明，不同的网络介导的经典的环绕和全球抑制。我们假设，这种全球性的，跨模态的抑制，它的行为自动在自下而上的方式，即使在镇静动物，是至关重要的刺激显着性在视顶盖的地图的创建。
Stimulus selection for gaze and spatial attention involves competition among stimuli across sensory modalities and across all of space. We demonstrate that such cross-modal, global competition takes place in the intermediate and deep layers of the optic tectum, a structure known to be involved in gaze control and attention. A variety of either visual or auditory stimuli located anywhere outside of a neuron's receptive field (RF) were shown to suppress or completely eliminate responses to a visual stimulus located inside the RF in nitrous oxide sedated owls. The essential mechanism underlying this stimulus competition is global, divisive inhibition. Unlike the effect of the classical inhibitory surround, which decreases with distance from the RF center and shapes neuronal responses to individual stimuli, global inhibition acts across the entirety of space and modulates responses primarily in the context of multiple stimuli. Whereas the source of this global inhibition is as yet unknown, our data indicate that different networks mediate the classical surround and global inhibition. We hypothesize that this global, cross-modal inhibition, which acts automatically in a bottom-up fashion even in sedated animals, is critical to the creation of a map of stimulus salience in the optic tectum.