Gamma oscillations mediate stimulus competition and attentional selection in a cortical network model
Gamma oscillations mediate stimulus competition and attentional selection in a cortical network model
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DOI：
10.1073/pnas.0809511105
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发表时间：
2008-11-18
影响因子：
11.1
通讯作者：
Kopell, Nancy J.
中科院分区：
文献类型：
--
作者：
Borgers, Christoph;Epstein, Steven;Kopell, Nancy J.
多种刺激的同时表现可以降低腹腔外视觉皮层中神经元的发射速率，低于单个首选刺激引起的速率。我们描述了计算结果表明，这种显着效果如何从强烈的兴奋性驱动器到大量快速刺激性抑制性中间神经元的大量驱动力产生，这可能导致该人群中的连贯性丧失，从而提高了抑制的有效性。我们建议，在注意状态下，快速加快的中间神经元可能会受到第二类抑制性中间神经元的胆碱能激活而导致的抑制作用，这恢复了伽玛节奏性所需的条件。在我们的模型中，振荡和连贯性是紧急特征，而不是假设。伽马振荡反过来支持刺激竞争。该机制是“振荡选择”的一种形式，其中神经相互作用会改变调节发射速率的相位关系，并注意这些神经相互作用。
Simultaneous presentation of multiple stimuli can reduce the firing rates of neurons in extrastriate visual cortex below the rate elicited by a single preferred stimulus. We describe computational results suggesting how this remarkable effect may arise from strong excitatory drive to a substantial local population of fast-spiking inhibitory interneurons, which can lead to a loss of coherence in that population and thereby raise the effectiveness of inhibition. We propose that in attentional states fast-spiking interneurons may be subject to a bath of inhibition resulting from cholinergic activation of a second class of inhibitory interneurons, restoring conditions needed for gamma rhythmicity. Oscillations and coherence are emergent features, not assumptions, in our model. The gamma oscillations in turn support stimulus competition. The mechanism is a form of "oscillatory selection," in which neural interactions change phase relationships that regulate firing rates, and attention shapes those neural interactions.