昼夜节律系统与成人昼夜节律睡眠觉醒障碍

昼夜节律是存在于所有生命体中、接近24小时的内源性生物节律。昼夜节律与社会或环境节律的长期不同步,会引起睡眠、情绪等一系列变化。本文阐述了昼夜节律系统与睡眠之间的联系,重点介绍成人昼夜节律睡眠觉醒障碍疾病的临床研究成果,以期加强临床医生对该病的认识和诊治。     

环境光导致昼夜节律紊乱对睡眠的影响

目的:研究通过环境光扰乱正常昼夜节律对睡眠的影响。方法:使用小鼠昼夜节律模型(20小时一个循环,10小时见光,10小时避光),利用小鼠睡眠生物解析系统,记录脑电波和肌电波,分析睡眠觉醒量、不同时间睡眠觉醒波delta功率和睡眠时相转换等参数。结果:昼夜节律干扰后导致昼夜觉醒差异、非快速眼动睡眠差异(NREM),和快速眼动睡眠(REM)差异消失(P0.05),昼夜节律干扰后增加了觉醒和NREM睡眠之间的转换次数(P0.05),昼夜节律紊乱的光照时相在开始时没有delta功率减弱征象(P0.05)。结论:昼夜节律模型不会导致典型的睡眠剥夺,但是会对睡眠时间和质量会产生影响。本研究一步证实昼夜节律对睡眠调节有着重要的作用。     

环境光对哺乳动物昼夜节律和大脑功能的影响

昼夜循环对人类和其他动物的生理和行为有着巨大的影响。光照条件能影响动物的视觉成像,并通过向大脑中的生物钟中心发送信号来调整生理和行为的节律。环境光向生物钟传递信号的系统包含了一个复杂的神经递质复合体-受体-第二信使系统。在夜间曝光能迅速启动下丘脑视交叉上核中大量相关的早期基因。此外,许多白天活动的物种,通常都是在光照条件下获得认知。本文综述了环境光对哺乳动物睡眠、生物节律、大脑认知能力和基因表达等生理和行为方面的影响。     

啮齿类动物的昼夜节律器及光周期对其影响机制

节律性（ｒｈｙｔｈｍｉｃｉｔｙ）是生命的基本特征之一,从单细胞生物到哺乳类动物的各种功能活动,生长繁殖乃至某些细微的形态结构,随着时间的推移都可能呈现某种有规律性的反复改变,这就是生物周期性,或生物节律性,亦称生物节律（ｂｉｏｌｏｇｉｃａｌｒｈｙｔ...     

昼夜节律钟调控代谢的研究进展

生理和行为的昼夜节律性调控对健康生活是必需的。越来越多的流行病学和遗传学证据显示昼夜节律的破坏与代谢紊乱性疾病相关联。在分子水平上,昼夜节律受到时钟蛋白组成的转录一翻译负反馈环的调控。时钟蛋白通过以下两种途径调节代谢：首先,时钟蛋白作为转录因子直接调节一些代谢关键步骤的限速酶和代谢相关核受体的表达,其次作为代谢相关核受体的辅调节因子来激活或抑制其转录活性。虽然时钟蛋白对代谢途径的调节导致代谢物水平呈昼夜节律振荡,但是产生的代谢物反过来又可以影响昼夜节律钟基因的表达,进而影响昼夜节律钟。深入研究昼夜节律钟与代谢的交互调节可能为治疗某些代谢紊乱性疾病提供新的治疗方案。     

温度对红尾沙蜥代谢昼夜节律的影响

爬行动物很多生理、生化和行为指标都表现出昼夜节律。代谢昼夜节律不仅涉及内在因子的固有控制,而且受到多种外部因素的影响。为了探究温度对代谢昼夜节律的影响,在恒定的温度下(18℃和28℃)测定了红尾沙蜥Phrynocephalus erythrurus体温、心率、标准代谢率(SMR)和血糖浓度的昼夜变化。结果表明:(1)在2个温度下红尾沙蜥体温没有明显的昼夜变化;(2)昼间SMR明显高于夜间,18℃下SMR水平以及SMR昼夜变化的范围都低于28℃下的结果;(3)心率的变化也与代谢率的变化一致,但最低点提前了2 h;(4)28℃下的血糖浓度整体水平显著高于18℃下的,而波动规律却不同:28℃条件下白天平均值高于晚上,血糖浓度在16∶00显著高于20∶00、00∶00和12∶00;18℃条件下,血糖浓度在20∶00和08∶00明显低于00∶00和12∶00(P0.05),而在04∶00和16∶00处于中间水平。该研究证实了红尾沙蜥SMR、心率和血糖浓度等生理生化指标也存在明显的昼夜节律,虽然这种现象受环境温度的影响,但主要还是由内在因子决定,这可能与某些激素的分泌活动有关。     

昼夜节律时钟研究的最新进展

昼夜节律时钟研究的最新进展赵文会（中国科学院国家基因研究中心,上海２００２３３）关键词昼夜节律时钟所有真核生物甚至一些原核生物都有一个基本特性：它们的生化、生理和行为等生命活动过程有昼夜节律性。即使没有外界环境因素刺激,没有任何时间线索,它们的生命活...     

家兔睡眠一觉醒的昼夜节律——电生理学与行为的研究

1.本工作以皮层电图、海马脑电图、眼动电图、肌电图和大体行为作指标,系统地观察了实验室家兔的睡眠-觉醒昼夜节律,分析了动物行为与海马脑电图的相互关系以及绒毛膜促性腺激素对雌兔异相睡眠的影响。2.家兔的睡眠-觉醒周期可分为:(1)活动期(59.4±2.9%);(2)安静清醒期(4.4±0.3%);(3)瞳睡期(4.2±0.1%);(4)浅慢波睡眠期(12.7±1.4%),(5)深慢波睡眠期(13.8±1.7%),(6)异相睡眠期(5.6±0.3%)。每一睡眠周期平均约20分,睡眠主要出现在12:00—15:00和0:00—3:00。3.海马脑电图的变化与睡眠、觉醒及其他行为变化密切相关。主要表现在清醒、随意运动和异相睡眠时出现θ节律,慢波睡眠时为不规则慢波。4.静脉注射绒毛膜促性腺激素可使雌兔异相睡眠时间延长。     

动物体温调节的昼夜节律

本文介绍了无脊椎动物,外热脊椎动物(鱼类、两栖类和爬行类)、内热脊椎动物(哺乳类和鸟类)体温调节的昼夜节律表现,列举了许多动物体温变化的资料,对教师拓宽知识面和教学参考皆有益。     

Influence of acoustic stimulation on the circadian and ultradian rhythm of premature infants

The aim of the present study was to evaluate the development of the circadian rhythm of the salivary cortisol in premature infants and its correlation with the onset of the sleep–activity behavior pattern during the first 3 weeks of life under controlled light:dark conditions. Furthermore, we investigated the influence of acoustic stimulation by audiotaped lullabies or the maternal voice on the cortisol values and long-term sleep–activity patterns. The study was a block-randomized, prospective clinical trial with a study population of 62 preterm neonates (30?<?37 gestational age). We compared two study groups who listened either to music or to the maternal voice (music: N?=?20; maternal voice: N?=?20) with a matched control group (N?=?22). The acoustic stimulation took place every evening between 20:00 and 21:00?h for 30?min over a period of 2 weeks. The cortisol values and activity–rest behavior of the neonates were determined during the first 3 weeks of life on the 1st, 7th and 14th day. Actigraphic monitoring was used to record the activity pattern continuously over 24?h and a validated algorithm for neonates was used to estimate sleep and wakefulness. The saliva samples were obtained 10?min before and 10?min after the acoustic interventions for the study groups. Additionally, saliva samples were obtained from the control group seven times over a 24-h period (20:00, 21:00, 01:00, 05:00, 08:00, 13:00 and 17:00?h). The cortisol data were analyzed by fast Fourier transformation to assess periodic characteristics and frequencies. Hierarchical linear modeling was further performed for the statistical analysis. Results: The cortisol rhythm analysis indicated a circadian rhythm pattern for only one premature infant, all others of the neonates showed no circadian or ultradian rhythm in cortisol. Cortisol level of the premature neonates was significantly higher during the first day of the study period at night-time (median: 17.1?nmol/L, IQR?=?9.7–24.4?nmol/L) than on days 7 (median: 9.6?nmol/L, IQR?=?4.7–14.6?nmol/L; Tukey-HSD, z?=?4.12, p?<?0.001) and 14 (IQR?=?5.8–13.7?nmol/L; Tukey-HSD, z?=?2.89, p?<?0.05). No significant effect of acoustic stimulation was observed on the cortisol concentration and sleep–wake behavior. The activity–sleep rhythm of preterm neonates was dominated by ultradian rhythm patterns with a prominent period length of 4?h (30.5%). Activity frequencies of neonates were also significantly higher overnight on the first study day (mean: 329?±?185.1?U) than of night seven (mean: 260.2?±?132.4?U; Tukey-HSD, z?=?2.50, p?<?0.05). Quiet-activity patterns increased, whereas high-activity patterns decreased during the observation period. Average sleep time increased significantly during the study time from day 1 to day 7 (Tukey-HSD, z?=?2.51, p?<?0.05). In conclusion, premature infants showed higher cortisol levels – without a circadian rhythmicity – and higher activity frequencies in the first days after birth which may reflect an adaptation process of neonates after birth. Cortisol concentrations and the activity patterns were not influenced by music interventions.     

Dual-scope of circadian rhythm biology

Sleep and Biological Rhythms -     

Influence of the season on the circadian rhythm of serum lipids in male Wistar rats

Young male Wistar rats were adapted to a 12:12 h light: dark regimen (7 a.m. to 7 p.m., 7 p.m. to 7 a.m.), with free access to food and water. In January, April, July and October they were killed at 3-hour intervals and non-esterified fatty acids, tri-glycerides, total cholesterol and phospholipids were determined in their serum. Serum cholesterol was the least influenced by the season; a rhythm was present in all the seasons, the acrophases came in approximately the same part of the day and the mean adjusted oscillation (mesor) values (in the cosinor test) did not differ the whole year round. Serum triglycerides displayed a rhythm except in the summer; their autumn values were lower and their curves attained the maximum in different parts of the photophase. Non-esterified fatty acids and phospholipids were found to be significantly influenced by the season; the shapes of their curves and their maxima varied during the year. For evaluation of the influence of the seasons on the circadian oscillations of lipid metabolism in the rat, information on the ratio of the formation and utilization/degradation of tissue lipids in the various parts of the year is still lacking.     

视交叉上核的内源性昼夜节律以及光,谷氨酸和NO的调制作用

自从发现视交叉上核（ＳＣＮ）中有直接的视网膜下丘脑投射纤维以来,ＳＣＮ的内源性节律及其调节机制受到广泛重视,已成为令人感兴趣的新课题。哺乳动物的２４ｈ昼夜节律而言,ＳＣＮ是主要的启步者,但ＳＣＮ内源性的振荡节律又受到环境光暗周期、谷氨酸和一氧化氮的拖拽。     

Influence of the light regimen on the circadian rhythm of serum lipids in the laboratory rat

Young male rats of a conventional Wistar breed were adapted for several weeks (3-6) to a 12:12 h light:dark (7 a.m. - 7 p.m., 7 p.m. - 7 a.m.) regimen (LD), to inversion of this standard regimen (DL), to continuous darkness (DD) or to continuous light (LL). After adaptation, groups of animals were killed at 3-hour intervals during the day and the basic lipid fractions were determined in their serum. Under the standard light regimen the cosinor test demonstrated a rhythm in all the indicators (triacylglycerols, total cholesterol, phospholipids) except for non-esterified fatty acids. When the regimen was inverted (DL), the peaks of the circadian non-esterified fatty acid and triacylglycerol curves shifted to the antiphase. The acrophases of "free-running" serum lipid rhythm under the DD regimen of the standard regimen rhythms differed in the case of cholesterol and phospholipids. In the case of triacylglycerols and phospholipids there was disagreement between the DD and LL regimen curves. With reference to the localization of the acrophase under the DD and LD regimens it was assumed that the influence of the light regimen on the synchronization of circadian rhythms is small in the case of serum non-esterified fatty acids and triacylglycerols and that it is greater in the case of serum cholesterol and phospholipids.     

Metabolic response to feeding in Tupinambis merianae: circadian rhythm and a possible respiratory constraint

The diurnal tegu lizard Tupinambis merianae exhibits a marked circadian variation in metabolism that is characterized by the significant increase in metabolism during part of the day. These increases in metabolic rate, found in the fasting animal, are absent during the first 2 d after meal ingestion but reappear subsequently, and the daily increase in metabolic rate is added to the increase in metabolic rate caused by digestion. During the first 2 d after feeding, priority is given to digestion, while on the third and following days, the metabolic demands are clearly added to each other. This response seems to be a regulated response of the animal, which becomes less active after food ingestion, rather than an inability of the respiratory system to support simultaneous demands at the beginning of digestion. The body cavity of Tupinambis is divided into two compartments by a posthepatic septum (PHS). Animals that had their PHS surgically removed showed no significant alteration in the postprandial metabolic response compared to tegus with intact PHS. The maximal metabolic increment during digestion, the relative cost of meal digestion, and the duration of the process were virtually unaffected by the removal of the PHS.