脑力疲劳状态下认知功能损伤研究进展

脑力疲劳是指缺乏动机和警觉的主观感受,一般会出现注意力分散、警觉性降低、情绪低落烦躁、工作绩效下降等现象。认知功能包括注意力、记忆、计算、时空间定向、语言的理解和表达,以及更为高级的能力。认知功能损伤会受到诸多因素的影响,其中脑力疲劳是造成认知损伤的原因之一。本文主要通过该领域的相关研究论文,研究脑力疲劳对注意力、执行功能、情绪和学习记忆四个方面认知功能的影响,以及对脑力疲劳可能引起认知功能损伤的神经生物学机制进行探讨。     

灵长类动作理解的镜像神经机制研究进展

灵长类动作理解(understanding of actions)的神经机制是认知神经科学研究的重要内容,它的阐明对于揭示灵长类特有的一些高级认知行为的本质和过程具有重要意义。就灵长类动物而言,个体对其同类做出动作的识别以及理解是其一切社会行为的基础,但是迄今为止我们对其动作理解的神经机制还知之甚少。随着镜像神经元成为近年来国外认知神经科学与认知人类学研究的热点,人们通过神经生理学和脑成像等技术,陆续发现和证明了其在灵长类动作理解过程中的重要作用。本文综述了近年来关于灵长类动作理解的镜像神经机制的研究成果,介绍了镜像神经元在灵长类动作理解过程中的一些新认识及其在该能力进化和发育等方面的作用,并对当前一些实验中遗留的问题与灵长类动作理解领域的未来研究方向作了反思与展望。     

运动性疲劳对血液流变学的影响

运动性疲劳是运动生理学和运动医学的核心问题。如何彻底消除疲劳,关键在于确定运动性疲劳的发生机制。综述了当前国内外在大强度运动所致运动性疲劳对血液流变学影响的研究成果。为进一步探讨运动性疲劳的发生机制,从而寻找迅速和彻底消除运动疲劳的措施提供理论依据。     

疲劳的现代研究

作为21世纪危害人类健康的重要因素,疲劳正逐渐引起人们的关注.通过对Pub Med数据库进行检索,共检索文献4652篇,系统地围绕疲劳的定义、中医药学对疲劳的认识、疲劳的临床诊疗、疲劳的生物学机制和动物模型的研制及疲劳研究的展望方面展开述评,以对几十年来疲劳的相关研究进行回顾和展望.目前,有关疲劳的机制研究更多的关注中枢神经系统和内分泌系统.近10年来,随着神经影像学技术的发展,依靠脑功能成像技术等新技术的临床研究数量增多.然而疲劳的发病机制不仅是中枢内分泌系统失调的单纯作用结果,其涉及神经-内分泌-免疫网络的功能协调,并且其形成是从初始感受器经过脊髓、中枢神经、特定功能脑区、呼吸以及循环系统,最终到达终端线粒体的一个周而复始的循环链式反应,每一个环节都可以影响到疲劳的发生和严重程度,临床也可针对不同的反应位点和机制开展干预研究.总而言之,疲劳的研究已经从整体、笼统、单纯的躯体功能等方面,发展到了局部、具体、涉及中枢-神经-内分泌系统以及免疫系统等多方面的实验和临床探索,基因学和细胞器是今后研究的热点和方向.     

中枢疲劳研究与思考

中枢疲劳既可以作为独立疾病影响人们的日常工作和学习,又可以作为症状出现于多种慢性疾病,其定义和机制国内外说法不尽相同。中枢疲劳是由于中枢神经系统发生退行性或其他不良变化,从而导致躯体、神经、包括心理一系列的疲劳样反应。其机制涉及到中枢神经系统和外周传导系统等多个维度、多个节点的变化,充分把握中枢疲劳的概念本质及潜在生物学机制对其临床防治有着重要理论和实践意义。此外,动物模型作为基础研究的前提和必要工具是中枢疲劳研究过程中又一重要问题。本文在文献整理的基础上,先从定义的角度出发由疲劳引申到中枢疲劳,将现阶段对中枢疲劳的不同概念阐述做一分析,并从机制和动物模型两个方面展开对国外研究进展进行综述。     

动物数能力的研究进展

动物数能力(numerical competence)是比较心理学、认知心理学和认知神经科学研究的热点之一。研究表明：(1)动物具有相对数量判断能力(relative numerousness judgments)和数量顿识能力(subitizing);(2)动物是否具有计数能力(counting)尚存在争议;(3)动物没有数量估算能力(estimation)。神经生理学研究发现,猴的后顶叶和前额叶在数功能方面扮演重要角色。     

瘦素在脑老化认知发展不同阶段中的作用

脑老化过程中伴随脑结构、功能退化和认知能力减退,其认知发展呈异质性,即发展的不均一性,有成功脑老化、正常脑老化、轻度认知功能障碍和阿尔茨海默病等状态。瘦素在不同认知状态下含量不同。研究发现,无神经病理改变的老年人群瘦素水平高,认知功能减退不明显;多数轻度认知功能障碍者瘦素水平降低;瘦素可改善阿尔茨海默病患者的认知障碍,被认为是一种潜在的认知增强剂。瘦素水平降低在脑老化认知障碍的发展中起重要作用。     

胰腺的病理生理学

本文主要论述胰腺的外分泌并着重于胰腺的炎症。在阐明胰腺炎发病学方面以及改善胰腺诊断方面的进步,使这一疾病症状表现的机制得以相当明了,并使治疗变得更加合理而有效。胰腺的生理学我们对胰腺生理学的知识是在研究了下列问题后获得的:胰腺外分泌及其调节机制;胆管和胰腺导管系统的解剖学和生理学;胰腺的蛋白质代谢以及胰腺导管压力改变对胰腺刺激所引起的反应。胰腺的外分泌胰液是一种主要由重碳酸     

情绪对时间知觉的影响及其神经生理学机制

时间在人们的认知过程中发挥着重要的作用。个体对于时间的感知一直是神经科学领域以及心理学领域关心的话题。一些研究表明,人们对时间的体验受情绪的影响。早期的相关研究主要集中在心理学领域。近年来,时间知觉的神经生理学机制研究取得了较多的进展,这使得研究者们能够从神经网络机制,神经递质变化以及突触可塑性等角度探索情绪如何调节时间知觉。本文对近年来有关情绪影响时间知觉的相关研究进行综述,以期为深入探索时间知觉的神经机制提供帮助。     

长航人员心理疲劳与GABA机制相关性探讨

心理疲劳指由于长期从事某项工作而出现的心理耗竭感,以及对任务的不能胜任感,并伴有情绪,认知,学习记忆力等方面的功能减退。长航人员作为一种特殊群体,其面对和承担的问题和压力都更加严峻,其心理疲劳的发病更具针对性,严重影响了我国海军整体实力。本文对长航人员心理疲劳从概念,表现等方面深入讨论,并进一步分析心理疲劳发病机制与GABA的相关性。心理疲劳的发生可能和中枢神经系统内抑制作用密切相关,而GABA作为脑内的经典抑制性神经递质在整个反应过程中起到关键和标志性作用。然而该结论还有待进一步分子生物学实验研究的证明。     

Platelet proteomics and its advanced application for research of blood stasis syndrome and activated blood circulation herbs of Chinese medicine

The development of novel and efficient antiplatelet agents that have few adverse effects and methods that improve antiplatelet resistance has long been the focus of international research on the prevention and treatment of cardiovascular and cerebrovascular diseases. Recent advances in platelet proteomics have provided a technology platform for high-quality research of platelet pathophysiology and the development of new antiplatelet drugs. The study of blood stasis syndrome (BSS) and activated blood circulation of traditional Chinese medicine (TCM) is one of the most active fields where the integration of TCM and western medicine in China has been successful. Activated blood circulation herbs (ABC herbs) of Chinese medicine are often used in the treatment of BSS. Most ABC herbs have antiplatelet and anti-atherosclerosis activity, but knowledge about their targets is lacking. Coronary heart disease (CHD), BSS, and platelet activation are closely related. By screening and identifying activated platelet proteins that are differentially expressed in BSS of CHD, platelet proteomics has helped researchers interpret the antiplatelet mechanism of action of ABC herbs and provided many potential biomarkers for BSS that could be used to evaluate the clinical curative effect of new antiplatelet drugs. In this article the progress of platelet proteomics and its advanced application for research of BSS and ABC herbs of Chinese medicine are reviewed.     

脑卒中后大鼠海马形态学演变趋势及中药的干预作用研究

目的:观察脑卒中后大鼠海马的形态学演变趋势及颐脑解郁方对其的干预作用。方法:雄性Wistar大鼠随机分为正常组、假手术组、MCI组、中药组、西药组、PSD组和VD组。采用同种系微栓子体外注入法制备MCI模型;PSD组术后7 d予21 d慢性不可预知的温和应激加孤养复制PSD模型;VD组术后28 d经水迷宫筛选后进入实验。假手术组、中药组及西药组分别予蒸馏水、颐脑解郁方、尼莫地平干预给药4周。于第1、2、4周光镜下分析海马的形态学结构变化。结果:MCI组海马锥体细胞数量显著减少,细胞排列不整齐。PSD组及VD组锥体细胞数量显著减少,胞体不同程度缩小、核固缩、核碎裂、核溶解,细胞排列不整齐,且呈进行性发展。中药组锥体细胞缺失较少,细胞排列整齐,核仁明显,西药组细胞变性有所改善,部分细胞核固缩,不如中药组改善明显。结论:颐脑解郁方可能通过益肾调气的主治功效改善Papez回路的病理改变,阻断病情的进一步发展。     

Functional disconnection and compensation in mild cognitive impairment: evidence from DLPFC connectivity using resting-state fMRI

The known regional abnormality of the dorsolateral prefrontal cortex (DLPFC) and its role in various neural circuits in mild cognitive impairment (MCI) has given prominence to its importance in studies on the disconnection associated with MCI. The purpose of the current study was to examine the DLPFC functional connectivity patterns during rest in MCI patients and the impact of regional grey matter (GM) atrophy on the functional results. Structural and functional MRI data were collected from 14 MCI patients and 14 age, gender-matched healthy controls. We found that both the bilateral DLPFC showed reduced functional connectivity with the inferior parietal lobule (IPL), superior/medial frontal gyrus and sub-cortical regions (e.g., thalamus, putamen) in MCI patients when compared with healthy controls. Moreover, the DLPFC connectivity with the IPL and thalamus significantly correlated with the cognitive performance of patients as measured by mini-mental state examination (MMSE), clock drawing test (CDT), and California verbal learning test (CVLT) scores. When taking GM atrophy as covariates, these results were approximately consistent with those without correction, although there may be a decrease in the statistical power. These results suggest that the DLPFC disconnections may be the substrates of cognitive impairments in MCI patients. In addition, we also found enhanced functional connectivity between the left DLPFC and the right prefrontal cortex in MCI patients. This is consistent with previous findings of MCI-related increased activation during cognitive tasks, and may represent a compensatory mechanism in MCI patients. Together, the present study demonstrated the coexistence of functional disconnection and compensation in MCI patients using DLPFC functional connectivity analysis, and thus might provide insights into biological mechanism of the disease.     

Déficit cognitif léger : mythe ou réalité ?

The concept of mild cognitive impairment, MCI, has been proposed by Petersen and described like a state between the cognitive changes of normal aging and very early dementia. However, MCI appears to be a heterogeneous clinical syndrome in term of etiological factors, clinical patterns or clinical course. New criteria of MCI are proposed for use in clinical research. Identification of patients at risk for Alzheimer disease, AD, is an important goal. Ongoing clinical and neuroimaging (magnetic resonance imaging (MRI), single photon emission computed tomography (SPECT),¹⁸F flouorodeoxyglucose-photo emission tomography (FDG-PET)) studies are focusing on the identification of those individuals with mild cognitive impairment (MCI) who are most likely to convert to AD.     

¿Previene la actividad intelectual el deterioro cognitivo? Relaciones entre reserva cognitiva y deterioro cognitivo ligero

An in-depth review is presented of the role that cognitive reserve plays in the emergence of (mild cognitive impairment (MCI), and its progression to dementia by using different indicators. The studies reviewed provide support to the hypothesis that the reserve influences the manifestation of symptoms of cognitive impairment and at least partially, in its progression to dementia. The role of indicators of reserve are discussed, such as educational level, work complexity and cognitive activity in these processes. A model is also presented that argues that people with MCI and low reserves show a steeper decline early in the process of deterioration, compared to the high level of reserve this marked deterioration would have at the end of the process, due to the protective role of this reserve. This raises the need for more empirical research to help consolidate this theoretical model.     

中医成药治疗甲型H1N1 流感研究进展

近年来,中医药治疗甲型H1N1流感取得了较好的临床疗效。尽管目前临床对甲型H1N1流感的治疗仍以西药为主,但西药抗病毒药存在副作用大,易引起耐药性等缺点,限制了治疗的效果。中医治疗甲型H1N1流感则具有独特的思路,根据甲型H1N1流感不同进展阶段的不同证型,选择不同的中药进行"辨证论治",不仅能减轻西药的不良反应,而且在疾病的治疗上也有独特的功效。我们总结了近来学者们对中医成药治疗甲型H1N1流感的临床及基础研究,将甲型H1N1流感分为轻、中、重三种,并分别根据症状与中医证型相匹配,梳理了临床用于治疗甲型H1N1流感的中医成药的适应证型与作用机制。因此,在西药进行抗病毒治疗的同时,根据疾病进展不同阶段的中医的证型,选用不同的中医方药,可有效减少西药的不良反应,取得更好的疗效。     

Precursor form of brain-derived neurotrophic factor and mature brain-derived neurotrophic factor are decreased in the pre-clinical stages of Alzheimer's disease

Brain-derived neurotrophic factor (BDNF) is critical for the function and survival of neurons that degenerate in the late stage of Alzheimer's disease (AD). There are two forms of BDNF, the BDNF precursor (proBDNF) and mature BDNF, in human brain. Previous studies have shown that BDNF mRNA and protein, including proBDNF, are dramatically decreased in end-stage AD brain. To determine whether this BDNF decrease is an early or late event during the progression of cognitive decline, we used western blotting to measure the relative amounts of BDNF proteins in the parietal cortex of subjects clinically classified with no cognitive impairment (NCI), mild cognitive impairment (MCI) or mild to moderate AD. We found that the amount of proBDNF decreased 21 and 30% in MCI and AD groups, respectively, as compared with NCI, consistent with our previous results of a 40% decrease in end-stage AD. Mature BDNF was reduced 34 and 62% in MCI and AD groups, respectively. Thus, the decrease in mature BDNF and proBDNF precedes the decline in choline acetyltransferase activity which occurs later in AD. Both proBDNF and mature BDNF levels were positively correlated with cognitive measures such as the Global Cognitive Score and the Mini Mental State Examination score. These results demonstrate that the reduction of both forms of BDNF occurs early in the course of AD and correlates with loss of cognitive function, suggesting that proBDNF and BDNF play a role in synaptic loss and cellular dysfunction underlying cognitive impairment in AD.     

基于体素的形态测量学在阿尔茨海默病及轻度认知功能障碍研究中的应用

阿尔茨海默病(Alzheimer's disease,AD)是发生于老年和老年前期、以进行性认知功能障碍和行为异常为特征的中枢神经系统退行性疾病,是老年痴呆中最常见类型。轻度认知功能障碍(mild cognitive impairment,MCI)是介于正常衰老和痴呆之间的一种中间状态,指有轻度的记忆或认知损伤,但尚未达到痴呆程度的一种状态,日常生活和社会功能不受影响,其中很大一部分患者最终进展为AD。临床诊断AD患者多已达中晚期,为了能早期诊断AD及预测MCI的转归,有关AD的生物学标注物的研究成为近年来的科研热点。AD患者颅脑的大体病理特征为脑萎缩,其萎缩有别于正常老龄化所致的退行性改变,有其自身特点,这种特定形式的萎缩有可能成为AD早期诊断的生物学标志物。基于体素的形态测量学(voxel-based morphometry,VBM)是一种基于像素水平对脑核磁图像进行自动、全面、客观分析的技术,可以定量分析全脑结构、刻画出局部脑区结构特征,是一种较好的脑形态分析工具,广泛用于阿尔茨海默病及轻度认知功能障碍的研究中,本文综述了近年来其研究进展,期望为临床及科研提供参考。     

The baseline and longitudinal changes of PCC connectivity in mild cognitive impairment: a combined structure and resting-state fMRI study

The baseline and longitudinal changes of the posterior cingulate cortex (PCC) connectivity were assessed in order to clarify the neural mechanism of mild cognitive impairment (MCI). Twenty-eight right-handed subjects (14 MCI patients and 14 healthy elders) participated in this study. Clinical and neuropsychological examinations were performed on all the subjects. PCC functional connectivity was studied by examining the correlation between low frequency fMRI signal fluctuations in the PCC and those in all the other brain regions. Additionally, we traced all the MCI patients and compared their PCC connectivity in the initial stage and that in 3 years later. We also explored the relationship between the PCC functional connectivity strength and cognitive performances. Our results are as follows: Functional connectivity between the PCC and a set of regions is decreased in MCI patients. Most of these regions are within the default mode network (DMN). Three years later, the regions of superior frontal gyrus (SFG) and middle frontal gyrus (MFG) presented further decreased connectivity to the PCC in MCI. In addition, we also find enhanced functional connectivity between PCC and medial prefrontal cortex (MPFC), PCC and anterior cingulate cortex (ACC) in MCI patients. At last, our research also shows that the PCC connectivity with some regions significantly correlates with the cognitive performances of patients as measured by mini-mental state examination (MMSE), and California verbal learning test (CVLT) scores. The baseline and longitudinal changes of the PCC connectivity in our study suggest that impairment and compensation coexist in the disease progress of MCI patients.     

DNA-repair in mild cognitive impairment and Alzheimer's disease

While the pathogenesis of the sporadic form of Alzheimer disease (late onset Alzheimer disease, LOAD) is not fully understood, it seems to be clear that a combination of genetic and environmental factors are involved and influence the course of the disease. Among these factors, elevated levels of oxidative stress have been recognized and individual differences in the capacity to deal with DNA damage caused by its effects have been the subject of numerous studies. This review summarizes the research on DNA repair proteins and genes in the context of LOAD pathogenesis and its possible prodromal stage, mild cognitive impairment (MCI). The current status of the research in this field is discussed with respect to methodological issues which might have compromised the outcome of some studies and future directions of investigation on this subject are depicted.