Department of Physiology, University of California, San Francisco, San Francisco, CA 94158-0444, USA; Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA, USA.
Center for Theoretical Neuroscience, College of Physicians and Surgeons and Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York City, NY 10027, USA.
Neuron. 2020 Dec 23;108(6):1181-1193.e8. doi: 10.1016/j.neuron.2020.11.013. Epub 2020 Dec 9.
Context guides perception by influencing stimulus saliency. Accordingly, in visual cortex, responses to a stimulus are modulated by context, the visual scene surrounding the stimulus. Responses are suppressed when stimulus and surround are similar but not when they differ. The underlying mechanisms remain unclear. Here, we use optical recordings, manipulations, and computational modeling to show that disinhibitory circuits consisting of vasoactive intestinal peptide (VIP)-expressing and somatostatin (SOM)-expressing inhibitory neurons modulate responses in mouse visual cortex depending on similarity between stimulus and surround, primarily by modulating recurrent excitation. When stimulus and surround are similar, VIP neurons are inactive, and activity of SOM neurons leads to suppression of excitatory neurons. However, when stimulus and surround differ, VIP neurons are active, inhibiting SOM neurons, which leads to relief of excitatory neurons from suppression. We have identified a canonical cortical disinhibitory circuit that contributes to contextual modulation and may regulate perceptual saliency.
上下文通过影响刺激显著性来引导感知。相应地，在视觉皮层中，对刺激的反应受到上下文（刺激周围的视觉场景）的调制。当刺激和周围环境相似时，反应会受到抑制，但当它们不同时则不会。其潜在机制尚不清楚。在这里，我们使用光学记录、操作和计算模型表明，由血管活性肠肽 (VIP) 表达和生长抑素 (SOM) 表达抑制性神经元组成的抑制性回路根据刺激和周围环境的相似性来调节小鼠视觉皮层中的反应，主要通过调节递归兴奋来调节。当刺激和周围环境相似时，VIP 神经元不活跃，而 SOM 神经元的活动导致兴奋性神经元的抑制。然而，当刺激和周围环境不同时，VIP 神经元活跃，抑制 SOM 神经元，从而使兴奋性神经元从抑制中得到缓解。我们已经确定了一个典型的皮层抑制回路，它有助于上下文调制，并可能调节感知显著性。
