Sleep slow wave changes during the middle years of life
Sleep slow wave changes during the middle years of life
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DOI：
10.1111/j.1460-9568.2010.07543.x
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发表时间：
2011-02-01
影响因子：
3.4
通讯作者：
Filipini, Daniel
中科院分区：
文献类型：
--
作者：
Carrier, Julie;Viens, Isabelle;Filipini, Daniel
人类非快速眼动(NREM)睡眠过程中的慢波(Sw；<；4 HZ和>；75mV)具有超极化和去极化的特征，前者表现为皮层神经元静息，后者表现为皮层神经元强烈放电。我们研究了年龄、性别和地形对健康青年(23.3+/-2.4岁)和中年(51.9+/-4.6岁)志愿者(n=87)短波特征动态变化的影响。老年受试者的短波密度和波幅均低于青年受试者。男性与年龄相关的低Sw密度在前额/额脑区域尤其明显，在那里它们更频繁地起源。年龄较大的受试者也表现出较长的短波正相和负相持续时间。这些最新结果表明，在年轻受试者中，皮质神经元将同步进入短波超极化和去极化阶段，而在年长受试者中，这一过程需要更长的时间，导致斜率较低，短波正负相长。重要的是，在控制Sw波幅后，中年受试者在前额叶、额叶、顶叶和枕叶来源上的斜率仍然比年轻受试者低。Sw密度、频率和正相时程的年龄相关效应在夜间开始时更为显著，此时动态平衡睡眠压力最高。年龄相关的Sw变化可能与突触密度和白质完整性的变化有关，并可能导致老年人睡眠更分散，在挑战下难以恢复和维持睡眠。
Slow waves (SW; < 4 Hz and > 75 mu V) during non-rapid eye movement (NREM) sleep in humans are characterized by hyperpolarization [surface electroencephalogram (EEG) SW negative phase], during which cortical neurons are silent, and depolarization (surface EEG positive phase), during which the cortical neurons fire intensively. We assessed the effects of age, sex and topography on the dynamics of SW characteristics in a large population (n = 87) of healthy young (23.3 +/- 2.4 years) and middle-aged (51.9 +/- 4.6 years) volunteers. Older subjects showed lower SW density and amplitude than young subjects. Age-related lower SW density in men was especially marked in prefrontal/frontal brain areas, where they originate more frequently. Older subjects also showed longer SW positive and negative phase durations. These last results indicate that, in young subjects, cortical neurons would synchronously enter the SW hyperpolarization and depolarization phases, whereas this process would take longer in older subjects, leading to lower slope and longer SW positive and negative phases. Importantly, after controlling for SW amplitude, middle-aged subjects still showed lower slope than young subjects in prefrontal, frontal, parietal and occipital derivations. Age-related effects on SW density, frequency and positive phase duration were more prominent at the beginning of the night, when homeostatic sleep pressure is at its highest. Age-related SW changes may be associated with changes in synaptic density and white matter integrity and may underlie greater sleep fragmentation and difficulty in recuperating and maintaining sleep under challenges in older subjects.