心血管疾病发生的生物钟现象与时间治疗学

生物钟是生物为了适应其生存环境周而复始的变化(如昼夜变化、四季变化等)在长期进化过程中形成的机体固有节律.研究表明生物钟节律的异常参与了心血管疾病的发生、发展.因此通过研究血管疾病的发生与生物钟的关系,建立新的治疗方法,即时间治疗学,来治疗和预防心血管疾病.     

生物钟与心律失常关系的研究进展

心律失常的发生具有昼夜节律,这种节律由生物钟产生。生物钟包括中枢生物钟和外周生物钟,通过一系列基因转录与翻译的负反馈调节,对机体生理与病理生理活动的昼夜节律产生广泛的影响。目前,我们已经认识到生物钟可以通过自主神经影响心脏电生理活动,也可以影响心肌细胞膜离子通道的表达,从而对心律失常发生的昼夜节律性产生影响。研究生物钟与心律失常之间的关系,对心律失常的预防、药物研究具有重要的意义。     

漫谈生物钟与轮班工作制

生物钟是指不直接受外在环境影响的、有机体内部的生物性的节律活动,如觉醒和睡眠的二十四小时节奏,脉搏、血压、体温的昼夜变化节奏,月经周期,胸电α节津等等。就是说,随着工作、娱乐、饮食、睡眠时间的社会化,人的机体在生理活动和工作效率上,也形成了每天的节律。     

生理节律与飞行安全

一、生理节律的由来及特点生理节律又称生物钟,它是人体内部活动的一种基本特征。人有时体力充沛,精神饱满,思维活跃,而有时则相反。这种有规律性的周期变化,就是生理节律的反应。生理节律是十分复杂的,从五十年前瑞典学者首先发现人体昼夜性节律起,目前,已有上百种之多。我们今天着重论述的是多,日性节律——体力、情绪和智力节律。多日性的体力和情绪节律,是本世纪初德国名医费里斯和维也纳心理学家斯沃博特通过长期的临床观察发现的。他们常常看到一些病人,如头痛、精神倦怠、食饮不良、     

感觉过程中的月经周期节律

在生物体系统中,生理节律活动是一种普遍的现象。这种生理节律对人的行为的影响正在不断地广泛地为人们所认识。在过去十年里,对月经周期节律的实验研究证实了一些生理变化与行为之间的相互关系。这些行为包括基本的感知觉过程,认知及社会性行为。对在感觉机能中的月经周期节律变化的研究涉及到视觉、嗅觉、听觉、味觉和触觉。本文旨在于综合对这五种感觉机能中月经周期变化的研究,以证明发生在感觉机能中月经周期变化的程度。     

神奇的生物三节律

本世纪初费里斯和斯沃博特发现一个奇怪的现象。有一些病人如头痛、精神倦怠等,每隔23天或28天就来治疗一次。于是他们就将23天称为“体力节律”,28天称为“情绪节律”。而在20年后,特里舍尔发现学生的智力是以33天为周期进行变化的。于是他就将其称为“智力节律”。后来人们就将“体力节律”、“智力节律”和“情绪节律”     

生命信息与生命活动的主动权

潮起潮落,蟹有感觉;时至三更,公鸡报晓;寒冬即临,蛙儿准备冬眠……各种生物虽然不知道什么是时钟,却都带有与大自然一致的“钟表”,科学家称之为生物钟。人类也有类似的生物钟。如起居有常、妇女的月经有常等。人从出生到垂老,体力、智力和情绪都经历周而复始的低落和高潮期。 人体为什么会带有生物钟呢?现有的研究认为:原来在大脑底部有一小束叫视神经核的视神经细胞,专门负责观察进入眼帘的光,不仅能辨别日夜,还能对白昼的长短、光的明暗等细微变化作出     

运动区Beta节律的活动特点及功能意义

人类大脑运动皮质的Beta(15~30 Hz)和Mu节律(8~14 Hz)有共同的活动特征,研究指出二者可能是联合的脑电成分。然而越来越多研究表明运动区Beta节律可能独立于Mu节律,且具有特殊的功能意义。线索诱发的Beta节律降低、运动前Beta节律降低和运动后Beta节律回复增强都是Beta与Mu节律不同的活动形式,表明运动区Beta节律有其独特的心理意义。本文主要对运动区Beta节律不同于Mu节律的活动特征及已有的理论解释进行了梳理和分析,并结合儿童研究的数据,从发展的角度对运动后Beta节律的理论假说进行了评述,最后在此基础上为进一步探索运动区Beta节律的功能意义提出了研究的展望。     

日间节律对个体认知行为的影响

本研究在实验室条件下,综合主观感受及客观行为表现考察我国大学生群体在一天内的节律变化。总体上,大学生的日间节律呈现出“上午（9:00～11:00）最佳,午后（13:00～15:00）下降,晚间（19:00～21:00）回升”的变化规律,但主客观指标反映的日间节律与不同神经行为功能的节律表现存在差异：客观警觉性注意在日间表现基本稳定,而主观困倦感午后波动明显,个体在15时的主观困倦感升至日间最高水平,而客观行为表现均已好转;17时,个体的主观感受、客观警觉性和工作记忆表现较好而抑制控制表现变差;19时,个体主观感受、工作记忆表现不佳而抑制控制表现好转。此外,上午至午后（9:00～13:00）,个体在不同认知负荷下的工作记忆表现也存在节律差异。本研究为个体合理规划日常活动、优化工作安排、提升生产安全等提供数据支持,也为进一步探究我国个体的日间节律和心理行为之间的关系提供初步证据。     

注意控制是否影响节律时间期待?

节律时间期待指人们利用节律时间信息预测下一个刺激何时出现的能力。然而,目前对于节律时间期待在多大程度上独立于注意控制过程还存在争议。对于该问题的探讨,首先介绍了节律时间期待的相关理论,包括动态注意理论和选择振荡理论,并对这两种理论进行了比较分析。然后重点回顾了注意控制与节律时间期待相关的研究,以往研究主要集中在听觉通道,且节律刺激以较快的速度呈现。将来的研究可以关注其他感觉通道和不同时间尺度下,注意控制是否影响节律时间期待。     

The effects of social defeat and other stressors on the expression of circadian rhythms

Most biological functions display a 24 h rhythm that, in mammals, is under the control of an endogenous circadian oscillator located in the suprachiasmatic nuclei (SCN) of the hypothalamus. The circadian system provides an optimal temporal organization for physiological processes and behavior in relation to a cyclic environment imposed upon organisms by the regular alternation of day and night. In line with its function as a clock that serves to maintain a stable phase-relationship between endogenous rhythms and the light-dark cycle, the circadian oscillator appears to be well protected against unpredictable stressful stimuli. Available data do not provide convincing evidence that stress is capable of perturbing the central circadian oscillator in the SCN. However, the shape and amplitude of a rhythm is not determined exclusively by the SCN and certain stressors can strongly affect the output of the clock and the expression of the rhythms. In particular, social stress in rodents has been found to cause severe disruptions of the body temperature, heart rate and locomotor activity rhythms, especially in animals that are subject to uncontrollable stress associated with defeat and subordination. Such rhythm disturbances may be due to effects of stress on sub-oscillators that are known to exist in many tissues, which are normally under the control of the SCN, or due to other effects of stress that mask the output of the circadian system. These disturbances of peripheral rhythms represent an imbalance between normally precisely orchestrated physiological and behavioral processes that may have severe consequence for the health and well being of the organism.     

Suprachiasmatic injection of a vasopressin antagonist modifies the circadian rhythm of food intake

To study the effect on the circadian feeding rhythm, injections of AVP and its antagonist were made into the suprachiasmatic nuclei (SCN) of rats after implanting cannulae into the bilateral SCN. Injections of arginine vasopressin (AVP) antagonist at the beginning of the light and dark phases disrupted the circadian rhythm of food intake while injections of AVP during the beginning of the light or dark phase did not disrupt the circadian rhythm. It may be concluded that endogenous vasopressin has a modulatory role in the mediation of the circadian feeding rhythm at SCN.     

Diurnal expression of period 2 and urocortin 1 in neurones of the non-preganglionic Edinger-Westphal nucleus in the rat

Period 2 (Per2) is an important clock gene involved in the regulation of the major circadian clock in the mammalian central nervous system, the suprachiasmatic nucleus. In addition, Per2 is expressed in many other stress-sensitive brain structures. We have previously showed that the non-preganglionic Edinger-Westphal nucleus (npEW) is the main site of the corticotropin-releasing factor peptide family member urocortin 1 (Ucn1) and that this peptide undergoes conspicuous expression changes in response to various stressors. Here, we hypothesized that in the rat npEW both Per2 and Ucn1 would be produced in a diurnal, rhythmical fashion. This hypothesis was tested by following this expected rhythm on two days in rats killed at four time points each day (Zeitgeber times 0, 6, 12, and 18). We showed the co-existence of Per2 and Ucn1 in the npEW with double-label immunofluorescence and demonstrated with quantitative RT-PCR and semi-quantitative immunocytochemistry diurnal rhythms in Per2 mRNA expression and Per2 protein content, each on a single different day, with a minimum at lights-off and a maximum at lights-on. We furthermore revealed a diurnal rhythm in the number of Ucn1-immunopositive neurones and in their Ucn1 peptide content, with a minimum at night and at the beginning of the light period and a peak at lights-off, while the Ucn1 mRNA content paralleled the Per2 mRNA rhythm. The rhythms were accompanied by a diurnal rhythm in plasma corticosterone concentration. Our results are in line with the hypothesis that both Per2 and Ucn1 in the rat npEW are produced in a diurnal fashion, a phenomenon that may be relevant for the regulation of the diurnal rhythm in the stress response.     

光照的警觉性作用

光照除了传统的视觉作用外, 还具有一定的非视觉效应, 包括调节昼夜节律、褪黑素分泌和警觉性等生理功能和行为表现。随着光照对生理节律影响研究的不断深入, 近来很多学者开始关注光照的警觉性作用。我们根据最新研究进展总结了：(1)警觉性的测量工具; (2)光照强度、时长、时间点、波长、色温等对光照警觉性作用的影响; (3)光照在治疗情绪障碍、调节生理节律、完善办公照明方面的应用; (4)提出了继续探讨光照警觉性作用的神经机制、优化参数特征和探讨混淆变量的研究方向。     

Analysis of the circadian rhythm of body temperature

Currently available methods for the analysis of circadian rhythms provide little help in the evaluation of the circadian rhythm of body temperature because they either assume that the circadian rhythm of body temperature approximates a cosine wave (which for many species is not true) or simply do not address important parameters, such as the amplitude and the shape of the temperature rhythm. The present paper presents methods for the computation and statistical evaluation of the period, amplitude, mean level, and general shape of the circadian rhythm of body temperature. The period is analyzed by the periodogram procedure, whereas the other parameters are analyzed by the histogram method. Both procedures are simple to implement and relatively insensitive to spurious data points. A simplified but fully operational program in BASIC is provided.     

Persistent impairments in hippocampal function following a brief series of photoperiod shifts in rats

The impact of an acute circadian disruption on learning and memory in male and female rats was examined. Circadian disruption was elicited using a brief series of photoperiod shifts. Previous research using male rats showed that acute circadian disruption during acquisition of a spatial navigation task impaired long-term retention and that chronic circadian disruption impaired acquisition of the same task. However, the long-term effects of acute circadian disruption following circadian re-entrainment and whether sex differences in response to circadian disruption exist are still unknown. For the present study, rats were trained on the standard, spatial version of the Morris water task (MWT) and a visual discrimination task developed for the eight-arm radial maze. After reaching asymptotic performance, behavioural training was terminated and the experimental group experienced a series of photoperiod shifts followed by circadian re-entrainment. Following circadian re-entrainment, the subjects were given retention tests on the MWT and visual discrimination task. Following retention testing, an extra-dimensional shift using the eight-arm radial maze was also performed. An acute episode of circadian disruption elicited via photoperiod shifts negatively impacted retention of spatial memory in male and female rats. Retention of the visual discrimination task and the ability to detect extra-dimensional shifts were not impaired. The observed impairments on the MWT indicate that hippocampal representations are susceptible to a small number of photoperiod shifts even if the association is acquired prior to rhythm manipulation and retention is assessed following rhythm stabilization. Effects were limited to a hippocampus-dependent task, indicating that impairments are specific, not global.     

Retrieval from semantic memory during a night without sleep

It has been demonstrated that retrieval performance from semantic memory varies during the day. Specifically, the retrieval of low- relative to high-dominance category members is slower in the morning compared to later in the day. It has been suggested that the effect is related to a circadian arousal rhythm, which steadily rises during the day and rapidly declines at night. This study examines retrieval from semantic memory during the night. Sixteen subjects performed a semantic classification task once every hour throughout one night without sleep. Classification latencies became progressively slower, and the time taken to retrieve low- relative to high-dominance category members increased from midnight to 4 a.m. The trend reversed between 4 and 7 a.m. The pattern of results closely parallels the hypothesised circadian arousal rhythm. It is suggested that the variation in retrieval performance as a function of time of day may be related to fluctuations in a circadian arousal rhythm.     

Age-specific problems in rhythmic timing

The authors investigated performance in 2 rhythm tasks in young (M = 23.8 years) and older (M = 71.4 years) amateur pianists to test whether slowing of a central clock can explain age-related changes in timing variability. Successive keystrokes in the rhythm tasks were separated by either identical (isochronous) time intervals or varying (anisochronous) intervals. Variability was comparable for young and older adults in the isochronous task; pronounced age effects were found for the anisochronous rhythm. Analyses of covariances between intervals rule out slowing of a central clock as an explanation of the findings, which instead support the distinction between target specification, timekeeper execution, and motor implementation proposed by the rhythm program hypothesis (D. Vorberg & A. M. Wing, 1996). Age stability was found at the level of motor implementation, but there were age-related deficits for processes related to target-duration specification.     

Central slowing during the night

The present study determined whether central information processing is subject to a circadian rhythm and, therefore, contributes to the well-known time-of-day effect on reaction time (RT). To assess the duration of central processing chronometrically, we employed the psychological refractory period (PRP) paradigm. In this task, subjects make fast responses to two successive stimuli. RT to the second stimulus is usually prolonged as the interval between the two stimuli decreases. This PRP effect is commonly attributed to a central-processing bottleneck. Subjects performed the PRP task every 2 hr during 28 hr of constant wakefulness under controlled conditions. The PRP effect was most pronounced in the early morning. We conclude that central processing is subject to a circadian rhythm, exhibiting a slowing during the night and a nadir in the early morning.