高特质焦虑个体执行控制功能及其脑网络研究

利用行为学及复杂网络分析方法,探讨高特质焦虑(HTA)个体执行控制功能及其脑功能网络特点.以16名HTA个体为研究对象、16名低特质焦虑(LTA)个体为对照,进行Simon空间认知冲突任务,同步记录行为数据(反应时间及正确率)及64导脑电(EEG)信号.对EEG数据进行同步似然分析,选择合适阈值构建脑网络拓扑结构并计算...     

Family and Illness Predictors of Outcome in Pediatric Brain Tumors

Investigated the prediction of cognitive and behavioral outcomesin 63 children with heterogenous brain tumors. Hierarchicalmultiple regression analyses were used to determine how family-relatedvariables added to the prediction of children's outcome overand above illness measures. The best predictors of children'sbehavior problems and adaptive behavior were family and demographicvariables, whereas the best predictors of achievement were illnessand demographic variables. A combination of family and illnessvariables, however, was the best predictor of intellectual functioning.In addition to identifying specific predictors of cognitiveand behavioral outcome in children with brain tumors, theseresults lend initial support for the inclusion of contextualfactors such as family stress, maternal coping, number of parentsin the home, and family SES measures in studies of how diseasefactors affect outcomes in pediatric brain tumor patients.     

磁刺激光明穴的脑电响应的脑功能网络构建与分析

经颅磁刺激技术与中医穴位刺激相结合的研究和应用,近年来已经取得一定进展,图论理论在脑科学研究领域中也进行一些探索,这些理论和技术的交叉与结合将为神经磁刺激技术的应用和脑科学的研究开启新的方向。利用互相关方法对磁刺激光明穴和假穴的脑电信号进行了两两通道间的线性时域关联特性分析,得出各通道间脑电数据的相关数量关系,并且以相关矩阵的形式表示,通过阈值大小的设定获取邻接矩阵,分别构建磁刺激光明穴与磁刺激假穴实验状态下脑电信号的脑功能网络图。结果发现,磁刺激光明穴的脑功能连接相比于磁刺激假穴的脑功能连接在枕叶(视觉联络区)、额叶区显著增多。利用基于图论的复杂网络理论,对所构建的脑功能网络特性参数进行参数比较和统计学分析。磁刺激光明穴使得脑功能网络发生变化,主要包括网络平均度增大、聚类系数增大、特征路径长度减小、全局效率和局部效率提高、小世界属性增强,并且这些差异经过统计学检验在均值差值上都有量化体现,通过统计检验发现磁刺激光明穴引起的脑功能网络参数的改变具有显著性差异(P<0.05)。研究提示,磁刺激光明穴相比磁刺激假穴,可以提高脑功能网络的全局效率和局部效率,缩短信息传播路径,使各个脑区之间的信息传递更加高效,为磁刺激技术施加于穴位改善神经功能提供一定的理论依据。     

Drosophila Neural Stem Cells in Brain Development and Tumor Formation

Neuroblasts, the neural stem cells in Drosophila, generate the complex neural structure of the central nervous system. Significant progress has been made in understanding the mechanisms regulating the self-renewal, proliferation, and differentiation in Drosophila neuroblast lineages. Deregulation of these mechanisms can lead to severe developmental defects and the formation of malignant brain tumors. Here, the authors review the molecular genetics of Drosophila neuroblasts and discuss some recent advances in stem cell and cancer biology using this model system.     

双语脑功能机制的脑磁图研究进展

双语者经常使用两种语言已被证明对语言和认知功能有广泛的影响,但是双语使用影响大脑的机制目前尚不清楚.脑磁图通过非侵入性方式测量微弱的脑磁场信号,可更准确反映脑部神经活动,对于脑疾病早期诊断和脑科学前沿研究具有重大意义.在阐述脑磁图技术的发展进程、分析方法和软件的基础上,从脑发育过程的双语优势、双语切换的脑机制研究、双语...     

中英双语者脑功能的研究方法

中英双语者脑功能的研究方法涉及到心理学、电生理和现代影像学技术等多种研究手段.研究中英双语者脑功能对于探索双语的神经基础,对指导外语教学与学习,以及治疗各种语言功能障碍均有重大意义.文中针对中英双语者脑功能研究手段与评估方法进行了分析总结,比较了各种方法的优缺点,并对该领域的发展趋势进行了展望.     

经颅直流电刺激干预工作记忆的脑功能网络研究

工作记忆是高级认知功能的重要基础,为探索经颅直流电刺激(tDCS)对工作记忆的影响及具体机制,招募18位被试参加实验,采集被试在伪/阳极/阴极tDCS刺激后三图、四图以及五图记忆负载任务中的行为数据(准确率、反应时长)与脑电信号.首先根据行为数据对工作记忆能力进行评估,再利用不同通道之间脑电信号的相关性,构建各状态下的...     

Temporal Stability of High-Frequency Brain Oscillations in the Human EEG

Temporal stability of a given measurement within individual participants is a desirable property of psychophysiological measures. The present study aims to examine the reliability of high-frequency oscillatory activity in the human electroencephalogram (EEG) across 4 sessions. Convolution of the EEG time series with Morlet wavelets yielded time-frequency representations of the signal for each session. Stability of both topography and time course of gamma-band activity (GBA) was determined for two participants performing a feature-based selective attention task in four separate sessions, spaced at weekly intervals. We found high temporal stability of non-phase-locked GBA typically occurring in time ranges between 200 and 500 ms following presentation of a stimulus, both in terms of topography and time course. Early phase-locked GBA (80-120 ms) showed higher variability with respect to topography, but was consistent in terms of time course. We conclude that measures of high-frequency oscillatory activity as used in the cognitive neurosciences meet stability requirements necessary for meaningful interpretation of this parameter of brain function.     

青少年肌阵挛癫痫患者的大尺度脑网络研究

采用静息态功能性磁共振成像(rs-fMRI)数据探究青少年肌阵挛癫痫(JME)患者大尺度脑网络的变化。采集17例JME患者和15名正常志愿者的脑部静息态功能磁共振成像数据,两组均使用偏相关系数构建静息态脑网络。分别计算JME患者组与正常对照组的阈值,构建二值化脑网络。计算两组被试各个脑区的介数值,采用双样本t检验对比两组脑网络介数值的差异(Bonferroni 校正,P<0.01),找出介数值发生显著变化脑区。结果表明,偏相关系数构造的脑网络具有小世界属性。JME患者组脑网络中脑区的介数值相比正常对照组有显著性差异。与正常对照组相比,JME患者组介数值显著降低的脑区有2个,介数值显著升高的脑区有17个。其中属于默认模式网络(DMN)的脑区有8个,属于突显网络(SN)的脑区有5个。JME患者组介数值显著降低的脑区有右侧中央旁小叶和右侧后扣带回,介数值显著增高脑区主要是右侧背外侧额上回、左侧枕中回、右侧楔前叶和右侧舌回等。JME患者介数值发生显著改变的脑区主要属于默认模式网络和突显网络。可以推断出默认模式网络和突显网络内部脑区间连接发生改变,信息传递产生变化。由此可能会导致JME患者大脑功能发生改变,造成患者的认知能力与执行能力等功能受损。     

帕金森病人脑电溯源与脑功能网络特性研究

帕金森病是老年人群中常发的神经退行性疾病,目前仍然缺乏公认的特异生化诊断指标。为了探索帕金森患者和健康受试的脑电差异,对26 名帕金森患者和26 名健康受试者进行闭眼静息态EEG的采集,利用MMSE和MoCA量表对受试者的认知功能进行主观评定,利用UPDRS和H&Y分级对受试者的运动功能进行评估。首先采用标准化低分辨率脑电磁层析成像对两组受试者脑电信号进行了溯源分析,而后采用滞后相位同步方法对脑功能网络进行差异性分析,进而对比分析两组受试者脑功能网络的拓扑特性。溯源分析结果表明,与健康对照组相比,PD组存在差异的脑区是枕叶和顶叶,α2频段楔前叶(BA7)电流密度显著降低;β1频段额叶与枕叶之间脑功能连接降低,患者脑功能网络的平均聚类系数C、全局效率E_g和节点度D比健康对照组显著降低(P<0.01)(患者: C=0.54±0.14,Eg=0.71±0.09,D=26.88±9.88;健康对照组: C=0.75±0.13,Eg=0.83±0.09,D=42.21±11.19),患者组平均特征路径长度L比健康对照组显著升高(患者: L=1.61±0.2;健康对照组: L=1.34±0.19,P< 0.01)。本研究α2频段楔前叶电流密度显著降低以及β1频段脑功能连接效率降低对帕金森病的诊断具有指导意义。     

动态因果模型在脑网络研究中的应用进展

大脑各功能区之间的有效连接是脑科学研究领域的一个重要内容.研究在不同情形下相关脑区之间有效连接所构成的大脑网络,对于全面理解大脑的功能机制,治疗各种与大脑相关疾病,开发脑功能具有重要意义.动态因果模型是一种分析大脑有效连接的优势方法.结合功能性磁共振成像、脑电、近红外脑功能成像等3种检测技术,综述动态因果模型的相关研究...     

Protein Kinase C In Larval Brain of Wild-type and Dunce Memory-Mutant Drosophila

Protein kinase C activity has been measured in extracts of larval brain of Drosophila melanogaster, with the synthetic nonapeptide substrate Ala-Ala-Ala-Ser-Phe-Lys-Ala-Lys-Lys-amide. Protein kinase C activity in such extracts is abolished in a Ca²⁺-dependent manner at 18°C, and partly converted to a form independent of effectors. The decay of protein kinase C activity can be prevented by leupeptin or a crude calpastatin preparation isolated from fly heads, indicating the presence of the Ca²⁺-dependent neutral protease, calpain, in larval brains. The total protein kinase C levels were nearly the same in wild type and three different dunce “memory-mutant” strains. In contrast, the soluble/particulate activity ratios were different: wild-type, 0.91; dunceM11, 0.46; dunceM11/Df(1)dm75,49, 1.23; dunce², 0.88. These data suggest that the membrane adherence of protein kinase C in larval brain is governed by the actor of genes other than dunce.     

颅脑减速碰撞中脑组织空化效应的模拟研究

目的:构建一种新的方法用于再现颅脑减速撞击过程中对冲部位的空化效应.方法:制作含微气泡的透明颅脑物理模型,并将其安放在竖式颅脑减速撞击移动平台上.在高强度灯光的照明环境中,将移动平台以40 cm的高度自由下落而撞击固定台面,同时采用高速摄像记录减速撞击的整个过程.之后用序列图片分析软件计算微气泡的体积与平均压力的变化,研究碰撞过程中脑组织的空化效应.结果:位于撞击对侧的微气泡在撞击过程中其体积明显增大,位于撞击侧的微气泡在撞击过程中其体积减小,位于中性点的微气泡在撞击过程中其体积增减不明显.结论:该实验结果表明颅脑对冲部位出现了负压,存在空化现象.清晰直观地再现了颅脑减速撞击过程中对冲部位的空化效应.有助于在一定程度上较好地认识颅脑减速撞击过程中脑组织内动态应力的分布特点,为阐明交通事故伤中较为常见的颅脑"对冲伤"的力学发生机制提供一定的方法和实验基础.同时该方法对于研究颅脑减速撞击损伤的致伤机理及其诊断和防护具有重要意义.     

The Evolution and Development of Neural Superposition

Visual systems have a rich history as model systems for the discovery and understanding of basic principles underlying neuronal connectivity. The compound eyes of insects consist of up to thousands of small unit eyes that are connected by photoreceptor axons to set up a visual map in the brain. The photoreceptor axon terminals thereby represent neighboring points seen in the environment in neighboring synaptic units in the brain. Neural superposition is a special case of such a wiring principle, where photoreceptors from different unit eyes that receive the same input converge upon the same synaptic units in the brain. This wiring principle is remarkable, because each photoreceptor in a single unit eye receives different input and each individual axon, among thousands others in the brain, must be sorted together with those few axons that have the same input. Key aspects of neural superposition have been described as early as 1907. Since then neuroscientists, evolutionary and developmental biologists have been fascinated by how such a complicated wiring principle could evolve, how it is genetically encoded, and how it is developmentally realized. In this review article, we will discuss current ideas about the evolutionary origin and developmental program of neural superposition. Our goal is to identify in what way the special case of neural superposition can help us answer more general questions about the evolution and development of genetically “hard-wired” synaptic connectivity in the brain.     

Brain temperature dependent changes in the electroencephalogram power spectrum of humans and animals

In animals, changes in brain temperature induce a shift in frequencies in the electroencephalogram (EEG). Given the large decreases in body and brain temperature that occur during hibernation, putative functions that were previously ascribed to certain EEG frequencies are no longer valid because of the progressive shift away from the original frequency. In the present review it is proposed that even moderate temperature changes in humans and animals, such as those across the circadian or menstrual cycle, or induced by drugs, have a significant effect on EEG frequencies and the corresponding power spectrum. Alterations in the relative EEG power spectrum, in studies where body temperature also changes, may not be a direct cause of the treatment under investigation, but a consequence of effects on body or brain temperature. However, these effects on the EEG power spectrum are usually interpreted to result directly from the experimental treatment.     

创伤性脑损伤活体脑片不同时相的脂质过氧化损伤

目的 观测创伤性脑损伤后不同时间大鼠脑组织的脂质过氧化损伤。方法 70只SD大鼠随机分为假损伤组（n=10）和脑损伤组，损伤组按伤后1、6、24、48、72和168h观察时间点分为6个亚组（n=10）。用Feeney氏自由落体撞击法制作重型颅脑损伤模型。利用激光扫描共聚焦显微镜观察损伤后不同时间荧光探剂2，7-二氯氢化荧光素（H2DCFDA）与碘化丙啶（PI）标记的活体脑片细胞内脂质过氧化物的动态变化和细胞死亡程度。结果 ①1、6、24h损伤组脂质过氧化物明显增加（P〈0．05），48h达到峰值，之后下降，72h已显著下降（P〈0．05），168h恢复正常水平。②1、6h损伤组神经细胞死亡明显增加（P〈0．05），24h达到峰值，之后维持不变，24、48、72及168h各损伤组之间细胞死亡无明显差异（P〉0．05）。③脂质过氧化物引起神经细胞死亡。结论 创伤性脑损伤早期（〈72h）脑组织即发生脂质过氧化反应引起神经细胞死亡，并且将持续一周。脂质过氧化物在创伤性脑损伤的继发损害中起重要作用。     

rTMS联合运动训练对静息态脑网络影响的研究

重复经颅磁刺激(rTMS)联合运动训练可以提高肢体运动能力,在脑卒中后的运动康复中有重要的应用价值。探讨rTMS联合运动训练对静息态脑网络的影响。招募10名健康受试者,使用1 Hz rTMS刺激优势半球,结束后非利手立即执行运动训练,以提高非利手的运动能力,rTMS联合运动训练共持续14天。采集rTMS联合运动训练前后闭目静息态的脑电(EEG)信号,使用相位延迟指数(PLI)进行功能连接性分析,并以PLI值为边的权重计算依据来建立有权无向脑网络,计算网络节点的最短路径长度和节点效率,使用非参数符号秩和检验进行统计学分析。结果发现,rTMS联合运动训练使EEG低频段(theta和alpha)脑功能区间的连接显著增加、高频段(beta、gamma₁和gamma₂)显著降低,对脑功能区内的连接影响较小。特别地,采取rTMS联合运动训练,使alpha频段非优势侧中央区与优势侧额叶区(训练前0.141 4±0.102 5,训练后0.217 2±0.134 7,P<0.05)、非优势侧额叶区(训练前0.141 0±0.109 9,训练后0.205 9±0.136 1,P <0.05)的功能连接性显著增加。网络特征结果显示,节点效率在低频段增加、高频段降低,而节点最短路径长度表现出相反的结果,其中gamma₂频段在双侧中央区的节点效率(左中央区,实验前0.060 0±0.000 3,实验后0.042 9±0.001 3,P <0.05;右中央区,实验前0.060 7±0.002 3,实验后0.041 9±0.002 4,P <0.05)和最短路径长度(左中央区,实验前18.539 0±0.457 1,实验后28.585 8±1.001 4,P<0.05;右中央区,实验前18.650 8±0.438 6,实验后28.853 0±1.652 6,P <0.05)发生显著性的改变。通过该项研究,加深对rTMS联合运动训练促进运动能力神经机制的理解,为未来探究其对脑卒中、脑损伤患者脑活动的影响提供帮助。