Sleep homeostasis and cortical synchronization: II. A local field potential study of sleep slow waves in the rat
Sleep homeostasis and cortical synchronization: II. A local field potential study of sleep slow waves in the rat
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DOI：
10.1093/sleep/30.12.1631
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发表时间：
2007-12-01
期刊：
影响因子：
5.6
通讯作者：
Tononi, Giulio
中科院分区：
文献类型：
--
作者：
Vyazovskiy, Vladyslav V.;Riedner, Brady A.;Tononi, Giulio
研究目的：睡眠慢波活动（SWA，EEG功率在0.5和4.0 Hz之间）在非快速眼动睡眠（NREM）睡眠过程中稳态下降。根据最近的假说，睡眠SWA的稳态减少是由于皮质皮质连接强度的逐渐降低。这一假设进行了评估，在一个大规模的丘脑皮质模型，这表明，突触强度的减少，通过减少突触后电流的实施，导致较低的睡眠SWA在模拟的局部场电位（LFP）。SWA的降低与高振幅慢波的比例降低、慢波斜率降低和多峰波数量增加有关。在这里，我们通过从大鼠大脑皮层获得LFP记录并比较高稳态睡眠压力的条件来测试模型预测（早睡）和低稳态睡眠压力（晚睡）。设计：在基线睡眠期间和6小时睡眠剥夺后的皮质内LFP记录。设置：基础睡眠研究实验室。患者或参与者：WKY成年雄性大鼠。干预：N/A。测量和结果：早期睡眠（在主要睡眠阶段开始时的睡眠，睡眠剥夺后立即睡眠）与（1）高SWA，（2）许多大的慢波，（3）慢波的陡峭斜率，（4）罕见的多峰波的发生有关。相比之下，晚睡（在主要睡眠阶段结束时睡眠，睡眠剥夺结束后几小时睡眠）与（1）低SWA，（2）少数高振幅慢波，（3）慢波斜率降低，（4）多峰波频率增加有关。在大鼠中，睡眠SWA的变化与慢波的振幅和斜率以及多峰波数量的变化相关。慢波参数的这种变化与平均突触强度在睡眠过程中降低的假设是一致的。
Study Objective: Sleep slow-wave activity (SWA, EEG power between 0.5 and 4.0 Hz) decreases homeostatically in the course of non-rapid eye movement sleep (NREM) sleep. According to a recent hypothesis, the homeostatic decrease of sleep SWA is due to a progressive decrease in the strength of corticocortical connections. This hypothesis was evaluated in a large-scale thalamocortical model, which showed that a decrease in synaptic strength, implemented through a reduction of postsynaptic currents, resulted in lower sleep SWA in simulated local field potentials (LFP). The decrease in SWA was associated with a decreased proportion of high-amplitude slow waves, a decreased slope of the slow waves, and an increase in the number of multipeak waves. Here we tested the model predictions by obtaining LFP recordings from the rat cerebral cortex and comparing conditions of high homeostatic sleep pressure (early sleep) and low homeostatic sleep pressure (late sleep).Design: Intracortical LFP recordings during baseline sleep and after 6 hours of sleep deprivation.Setting: Basic sleep research laboratory.Patients or Participants: WKY adult male rats.Interventions: N/A.Measurements and Results: Early sleep (sleep at the beginning of the major sleep phase, sleep immediately after sleep deprivation) was associated with (1) high SWA, (2) many large slow waves, (3) steep slope of slow waves, and (4) rare occurrence of multipeak waves. By contrast, late sleep (sleep at the end of the major sleep phase, sleep several hours after the end of sleep deprivation) was associated with (1) low SWA, (2) few high-amplitude slow waves, (3) reduced slope of slow waves, and (4) more frequent multipeak waves.Conclusion: In rats, changes in sleep SWA are associated with changes in the amplitude and slope of slow waves, and in the number of multipeak waves. Such changes in slow-wave parameters are compatible with the hypothesis that average synaptic strength decreases in the course of sleep.