UCL Institute of Ophthalmology, University College London, Gower Street, London WC1E 6AE, UK.
UCL Institute of Neurology, University College London, Gower Street, London WC1E 6AE, UK; Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London WC1E 6AE, UK.
Cell Rep. 2018 Mar 20;22(12):3160-3167. doi: 10.1016/j.celrep.2018.02.092.
Changes in arousal modulate the activity of mouse sensory cortex, but studies in different mice and different sensory areas disagree on whether this modulation enhances or suppresses activity. We measured this modulation simultaneously in multiple cortical areas by imaging mice expressing voltage-sensitive fluorescent proteins (VSFP). VSFP imaging estimates local membrane potential across large portions of cortex. We used temporal filters to predict local potential from running speed or from pupil dilation, two measures of arousal. The filters provided good fits and revealed that the effects of arousal depend on modality. In the primary visual cortex (V1) and auditory cortex (Au), arousal caused depolarization followed by hyperpolarization. In the barrel cortex (S1b) and a secondary visual area (LM), it caused only hyperpolarization. In all areas, nonetheless, arousal reduced the phasic responses to trains of sensory stimuli. These results demonstrate diverse effects of arousal across sensory cortex but similar effects on sensory responses.
觉醒状态的变化调节着小鼠感觉皮层的活动，但不同小鼠和不同感觉区域的研究对于这种调节是增强还是抑制活动存在分歧。我们通过对表达电压敏感荧光蛋白（VSFP）的小鼠进行成像，同时测量多个皮层区域的这种调节。VSFP 成像估计了大片皮层的局部膜电位。我们使用时间滤波器来预测来自于奔跑速度或瞳孔扩张的局部电位，这两个是觉醒的衡量指标。滤波器提供了很好的拟合，并揭示了觉醒的影响取决于感觉模态。在初级视觉皮层（V1）和听觉皮层（Au）中，觉醒引起去极化，随后发生超极化。在桶状皮层（S1b）和二级视觉区（LM）中，它只引起超极化。尽管如此，在所有区域中，觉醒都减少了对感觉刺激串的相位反应。这些结果表明，在感觉皮层中，觉醒有不同的作用，但对感觉反应的作用相似。
