Snipes Sophia, Meier Elias, Meissner Sarah Nadine, Landolt Hans-Peter, Huber Reto
Child Development Center, University Children's Hospital Zürich, University of Zürich, 8032 Zürich, Switzerland.
Neural Control of Movement Lab, Department of Health Sciences and Technology, ETH Zürich, 8092 Zürich, Switzerland.
iScience. 2023 Jun 19;26(7):107138. doi: 10.1016/j.isci.2023.107138. eCollection 2023 Jul 21.
Being awake means forming new memories, primarily by strengthening neuronal synapses. The increase in synaptic strength results in increasing neuronal synchronicity, which should result in higher amplitude electroencephalography (EEG) oscillations. This is observed for slow waves during sleep but has not been found for wake oscillations. We hypothesized that this was due to a limitation of spectral power analysis, which does not distinguish between changes in amplitudes from changes in number of occurrences of oscillations. By using cycle-by-cycle analysis instead, we found that theta and alpha oscillation amplitudes increase as much as 30% following 24 h of extended wake. These increases were interrupted during the wake maintenance zone (WMZ), a window just before bedtime when it is difficult to fall asleep. We found that pupil diameter increased during this window, suggesting the ascending arousal system is responsible. In conclusion, wake oscillation amplitudes reflect increased synaptic strength, except during the WMZ.
保持清醒意味着形成新的记忆，主要方式是增强神经元突触。突触强度的增加会导致神经元同步性增强，这理应会使脑电图（EEG）振荡的幅度增大。睡眠期间的慢波情况确实如此，但清醒时的振荡尚未发现这种现象。我们推测这是由于频谱功率分析存在局限性，它无法区分振荡幅度的变化和振荡次数的变化。取而代之采用逐周期分析后，我们发现，在延长清醒24小时后，θ波和α波振荡幅度增加多达30%。这些增加在清醒维持区（WMZ）中断，这是临睡前一个难以入睡的时间段。我们发现，在此期间瞳孔直径增大，表明上行唤醒系统起了作用。总之，除了在清醒维持区，清醒时的振荡幅度反映了突触强度的增加。
