睡眠觉醒的昼夜和次昼夜节律发育

Circadian and ultradian rhythmic development in sleep-wake cycle

睡眠觉醒发育与脑发育密切相关,多数动物睡眠觉醒节律发育规律与人类相似,由脑内生物钟、睡眠觉醒中枢和内平衡稳态等因素调节。成人的觉醒与睡眠呈昼夜节律性出现,整夜睡眠20%为快动眼(REM)睡眠,80%为非快动眼(NREM)睡眠。NREM-REM睡眠转换周期为90~110 min,表现为次昼夜节律。足月新生儿觉醒与睡眠昼夜均匀分布,睡眠常以REM睡眠起始,REM与NREM睡眠各占50%,转换周期为50~60 min;3月龄开始显现昼夜节律分布,睡眠周期以NREM睡眠起始,10岁后NREM-REM睡眠周期呈现近似成年次昼夜节律水平。睡眠与觉醒的昼夜节律及次昼夜节律的发育参与个体的生理和心理发育过程,了解睡眠觉醒节律调控及发育,为理解脑发育和新生儿睡眠节律异常导致的疾病奠定理论基础。

The developmental pattern of sleep-wake cycle in most animals is similar to that in human, circadian and ultradian rhythmic formations of sleep-wake cycle depend on biological clock, sleep and wakefulness regulatory centers of the brain and homeostasis. Wakefulness and sleep in adults are presented as circadian rhythms. Sleep throughout a night normally contains 80% of non-rapid eye movement(NREM) and 20% of REM sleep. During the sleep period, NREM and REM sleep states alternate in a cyclic manner referred as to ultradian rhythms exhibiting each cycle for 90~110 min. Wakefulness and sleep in term newborns equally distribute at daytime and nighttime. The sleep in term newborns contains 50% of REM and 50% of NREM sleep,and generally begins with REM sleep and undergoes cyclically REM-NREM sleep cycles, each cycle lasting on average from 50 to 60 min. And at 3 months of age firstly appear a tendency of circadian rhythms. The appearance of NREM sleep at sleep onset occurs at 3 months of age, and the ultradian NREM-REM cyclicality in children who are more than 10 years of age approximates to the level of that in adults. Circadian and ultradian rhythmic development in sleep-wake cycle are essential to the individual physiological and psychological development. Understanding the regulation and development of sleep-wake rhythm will provide a deep insight into brain development, and fundamental theories for the diseases induced by rhythmic disturbances of sleepwake cycle in early life.