Extrastriate visual neurons show no firing rate change during a working memory (WM) task in the absence of sensory input, but both $\alpha \beta$ oscillations and spike phase locking are enhanced, as is the gain of sensory responses. This lack of change in firing rate is at odds with many models of WM, or attentional modulation of sensory networks. In this article we devised a computational model in which this constellation of results can be accounted for via selective activation of inhibitory subnetworks by a top-down working memory signal. We confirmed the model prediction of selective inhibitory activation by segmenting cells in the experimental neural data into putative excitatory and inhibitory cells. We further found that this inhibitory activation plays a dual role in influencing excitatory cells: it both modulates the inhibitory tone of the network, which underlies the enhanced sensory gain, and also produces strong spike-phase entrainment to emergent network oscillations. Using a phase oscillator model we were able to show that inhibitory tone is principally modulated through inhibitory network gain saturation, while the phase-dependent efficacy of inhibitory currents drives the phase locking modulation. The dual contributions of the inhibitory subnetwork to oscillatory and non-oscillatory modulations of neural activity provides two distinct ways for WM to recruit sensory areas, and has relevance to theories of cortical communication.

中文翻译：

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通过工作记忆的计算模型识别出抑制子网络对视觉皮层调制的不同贡献

在没有感觉输入的情况下，纹外视觉神经元在工作记忆 (WM) 任务期间没有表现出放电率变化，但是 $\alpha\beta$ 振荡和尖峰锁相都得到了增强，感觉反应的增益也是如此。这种放电率变化的缺乏与许多 WM 模型或感觉网络的注意调节不一致。在本文中，我们设计了一个计算模型，其中可以通过自上而下的工作记忆信号选择性激活抑制子网络来解释这种结果的星座。我们通过将实验神经数据中的细胞分割为假定的兴奋性和抑制性细胞，证实了选择性抑制性激活的模型预测。我们进一步发现这种抑制性激活在影响兴奋性细胞方面起着双重作用：它既可以调节网络的抑制基调，这是增强感觉增益的基础，也可以对突发网络振荡产生强烈的尖峰相位夹带。使用相位振荡器模型，我们能够证明抑制音调主要通过抑制网络增益饱和进行调制，而抑制电流的相位相关功效驱动锁相调制。抑制子网络对神经活动的振荡和非振荡调制的双重贡献为 WM 募集感觉区域提供了两种不同的方式，并且与皮层通信理论相关。使用相位振荡器模型，我们能够证明抑制音调主要通过抑制网络增益饱和进行调制，而抑制电流的相位相关功效驱动锁相调制。抑制子网络对神经活动的振荡和非振荡调制的双重贡献为 WM 募集感觉区域提供了两种不同的方式，并且与皮层通信理论相关。使用相位振荡器模型，我们能够证明抑制音调主要通过抑制网络增益饱和进行调制，而抑制电流的相位相关功效驱动锁相调制。抑制子网络对神经活动的振荡和非振荡调制的双重贡献为 WM 募集感觉区域提供了两种不同的方式，并且与皮层通信理论相关。