Shirota Ai, Kamimura Mayo, Kishi Akifumi, Adachi Hiroyoshi, Taniike Masako, Kato Takafumi
Department of Oral Physiology, Osaka University Graduate School of Dentistry, Suita, Japan.
Graduate School of Education, The University of Tokyo, Bunkyo-ku, Japan.
Front Physiol. 2021 Mar 24;12:623401. doi: 10.3389/fphys.2021.623401. eCollection 2021.
The aim of the present study was to characterize the cyclic sleep processes of sleep-stage dynamics, cortical activity, and heart rate variability during sleep in the adaptation night in healthy young adults.
Seventy-four healthy adults participated in polysomnographic recordings on two consecutive nights. Conventional sleep variables were assessed according to standard criteria. Sleep-stage continuity and dynamics were evaluated by sleep runs and transitions, respectively. These variables were compared between the two nights. Electroencephalographic and cardiac activities were subjected to frequency domain analyses. Cycle-by-cycle analysis was performed for the above variables in 34 subjects with four sleep cycles and compared between the two nights.
Conventional sleep variables reflected lower sleep quality in the adaptation night than in the experimental night. Bouts of stage N1 and stage N2 were shorter, and bouts of stage Wake were longer in the adaptation night than in the experimental night, but there was no difference in stage N3 or stage REM. The normalized transition probability from stage N2 to stage N1 was higher and that from stage N2 to N3 was lower in the adaptation night, whereas that from stage N3 to other stages did not differ between the nights. Cycle-by-cycle analysis revealed that sleep-stage distribution and cortical beta EEG power differed between the two nights in the first sleep cycle. However, the HF amplitude of the heart rate variability was lower over the four sleep cycles in the adaptation night than in the experimental night.
The results suggest the distinct vulnerability of the autonomic adaptation processes within the central nervous system in young healthy subjects while sleeping in a sleep laboratory for the first time.
本研究旨在描述健康年轻成年人在适应夜睡眠期间睡眠阶段动态、皮层活动和心率变异性的周期性睡眠过程。
74名健康成年人连续两晚进行多导睡眠图记录。根据标准标准评估传统睡眠变量。分别通过睡眠时段和转换来评估睡眠阶段的连续性和动态性。比较两晚之间的这些变量。对脑电图和心脏活动进行频域分析。对34名有四个睡眠周期的受试者的上述变量进行逐周期分析，并比较两晚之间的情况。
传统睡眠变量显示适应夜的睡眠质量低于实验夜。在适应夜，N1期和N2期的时段较短，觉醒期的时段较长，但N3期或快速眼动期没有差异。在适应夜，从N2期到N1期的标准化转换概率较高，从N2期到N3期的标准化转换概率较低，而从N三到其他阶段在两晚之间没有差异。逐周期分析显示，在第一个睡眠周期中，两晚的睡眠阶段分布和皮层β脑电图功率不同。然而，适应夜四个睡眠周期中心率变异性的高频振幅低于实验夜。
结果表明，年轻健康受试者首次在睡眠实验室睡眠时，中枢神经系统内自主适应过程存在明显的脆弱性。
