Vyazovskiy Vladyslav V, Riedner Brady A, Cirelli Chiara, Tononi Giulio
Department of Psychiatry, University of Wisconsin, Madison, WI 53719, USA.
Sleep. 2007 Dec;30(12):1631-42. doi: 10.1093/sleep/30.12.1631.
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).
Intracortical LFP recordings during baseline sleep and after 6 hours of sleep deprivation.
Basic sleep research laboratory.
WKY adult male rats.
N/A.
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.
In rats, changes in sleep SWA are associated with changes in the amplitude and slope of slow waves, and in the number of multi-peak waves. Such changes in slow-wave parameters are compatible with the hypothesis that average synaptic strength decreases in the course of sleep.
睡眠慢波活动（SWA，脑电图功率在0.5至4.0赫兹之间）在非快速眼动睡眠（NREM）过程中会进行稳态下降。根据最近的一个假说，睡眠SWA的稳态下降是由于皮质皮质连接强度的逐渐降低。该假说在一个大规模丘脑皮质模型中得到了评估，该模型表明，通过减少突触后电流实现的突触强度降低，会导致模拟局部场电位（LFP）中的睡眠SWA降低。SWA的降低与高振幅慢波比例的降低、慢波斜率的降低以及多峰波数量的增加有关。在这里，我们通过从大鼠大脑皮层获取LFP记录，并比较高稳态睡眠压力（早期睡眠）和低稳态睡眠压力（晚期睡眠）的情况，来检验模型预测。
在基线睡眠期间和睡眠剥夺6小时后进行皮质内LFP记录。
基础睡眠研究实验室。
WKY成年雄性大鼠。
无。
早期睡眠（主要睡眠阶段开始时的睡眠，睡眠剥夺后立即睡眠）与以下情况相关：（1）高SWA，（2）许多大的慢波，（3）慢波的陡坡，以及（4）多峰波罕见。相比之下，晚期睡眠（主要睡眠阶段结束时的睡眠，睡眠剥夺结束后数小时的睡眠）与以下情况相关：（1）低SWA，（2）高振幅慢波较少，（3）慢波斜率降低，以及（4）多峰波更频繁。
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睡眠过程中平均突触强度降低的假说相符。
