睡眠剥夺影响大脑功能区状态的非线性评价

采用近似熵研究睡眠剥夺（sleep deprivation，SD）对脑认知功能的影响，评价SD引起的大脑功能区状态的非线性变化．12名受试者在正常睡眠和一夜SD之后分别接受视觉注意力测试，记录自发脑电和诱发脑电，采用二维插值构建19导脑电近似熵脑信息图（brain information map，BIM）．结果表明，在SD状态下，自发脑电的近似熵在全脑范围内有不同程度的下降，额叶处大脑偏侧性发生变化，复杂度的中心从左脑转移到右脑；前额叶处诱发脑电近似熵值降低，而顶叶和颞叶处则升高．脑电近似熵可以作为指标来评价SD对脑认知功能的负向影响，BIM的变化趋势与从生理学及影像学角度的分析相吻合，与线性方法的研究结论一致，在一定程度上可以反映大脑功能状态，提供一条评价脑功能区状态变化趋势的思路．     

Effects of sleep deprivation on gamma oscillation of waking human EEG

This study compares and evaluates the effect of sleep deprivation （SD） on human brain cognition by analyzing the recorded EEG data under normal and 24 h sleep deprived states. EEG auditory event-related potentials were collected from 14 healthy volunteers, and the statistical values of wavelet-transformed EEG in gamma band were decomposed by parallel factor analysis （PARAFAC） to identify where the differences appeared in the time, frequency and spatial domains. The results showed that the changes of brain states caused by SD appeared around 40 Hz at about 400 ms after stimulation on prefrontal and frontal lobes. Negative effects of SD on neuronal activity and oscillation were observed. The analysis of the EEG data by the wavelet transform and PARAFAC can be an integrated way to estimate the change of brain states in the three domains.     

酒精对部分睡眠剥夺小鼠血细胞参数的影响

利用多平台法部分剥夺小鼠睡眠,在此基础上给予酒精灌胃,观察上述处理对动物血常规参数和血沉的影响.结果显示:睡眠剥夺使小鼠血液白细胞、淋巴细胞含量及百分比显著降低,红细胞、血红蛋白含量,红细胞压积显著升高;在此基础上再给予酒精灌胃,上述参数恢复至正常水平,但血沉显著升高.结果提示部分剥夺小鼠睡眠能抑制其免疫能力并可导致血液浓缩;而在此基础上再给予适量酒精灌胃可上调机体的免疫能力,但此时机体处于血沉加快的病理状态中.     

两耳分听汉字测验中大脑机能优势加工的超日节律效应

对３２名听力正常的大学生被试在日间进行连续８ｈ汉语单字词两耳分听测验,以检查大脑两半球加工汉字语音机能优势的时间性动态变化。结果发现：①所有被试左、右耳正确报告的词数未见有明显的周期性波动;②有１２例被试左、右耳正确占先报告词数的优势比出现了周期约为３ｈ的超日节律;③女性被试的平均节律周期长度明显长于男性。结果提示,大脑两半球控制的分听语词加工过程在部分被试中明显受到生物钟超日节律的调节。     

睡眠剥夺对大脑状态影响的时-频-空分析

结合脑电信号EEG的小波变换和非负矩阵分解,寻求正常睡眠和睡眠剥夺（sleep deprivation,SD）两种条件下,大脑状态在时域、频域和空域的主要差异,探讨其发生机制,并建立综合评价方法．为此,获取两种条件下11名受试者的听觉诱发电位,对脑电gamma频段做小波变换得到时频信息,采用ANOVA统计计算每个时频点的F检验值,对此进行两分量的非负矩阵分解结果表明,SD引起的大脑状态变化主要发生在40Hz左右,刺激后约400ms处的额叶和前额叶位置．基于此,分别从时频复合域、时域和空域的角度来分析具体的变化,发现SD引起gamma振荡减少,活动时间延迟,额叶功能区兴奋性降低,推断SD的作用机制在于降低了神经元的活动和同步化效应．分析表明结合EEG的小波变换和非负矩阵分解,可以建立一条从时、频、空三域全面评价大脑状态主要变化的途径．     

油橄榄叶提取物联合美沙酮对海洛因成瘾大鼠的脑组织结构及单胺递质的影响

目的:观察油橄榄叶提取物(olive leaf extract,OLE)联合美沙酮对海洛因依赖大鼠的脑组织结构及单胺递质的影响。方法:将28只健康大鼠随机分成正常组、模型组、OLE+美沙酮处理组和美沙酮处理组。按递增法采用皮下注射海洛因建立海洛因依赖大鼠模型,造模后药物处理30 d,在光学显微镜下观察大脑额叶皮层细胞结构的变化,利用荧光分光光度法检测脑中单胺类递质的含量。结果:与正常组相比,模型组海洛因依赖大鼠出现大脑额叶皮层结构不清、神经元发育不良、皮层厚度减小、脑单胺类递质含量明显增高;与模型组相比,OLE+美沙酮处理组和美沙酮处理组的大鼠大脑额叶皮层结构清晰、皮层厚度增加、脑单胺递质含量显著降低。结论:OLE联合美沙酮明显改善了海洛因依赖大鼠的戒断症状,保护了脑组织,其作用机制可能与脑内单胺递质的改变有关。     

睡眠剥夺对脑认知和脑电复杂性的影响

为研究睡眠对大脑功能的影响，考察了正常睡眠与睡眠剥夺情况下脑认知能力的变化，分析了两种状态下自发脑电和事件相关电位复杂性的差异．通过事件相关电位P300的潜伏期与幅度反映不同状态下的脑认知能力，采用小波熵方法分析其复杂性．实验采用数字脑电图仪记录19导脑电信号，用OB序列诱发视觉事件相关电位．结果发现，睡眠剥夺组的靶刺激反应时间明显增长，而P300幅度显著降低、潜伏期明显增加；小波熵分析结果表明，与正常睡眠组比较，睡眠剥夺组自发脑电的256点小波熵和事件相关电位的32点小波熵均值都显著降低．故得出结论：睡眠剥夺对人的认知和脑电复杂性均产生了负向影响．因此，睡眠对维持大脑的功能具有重要作用．     

Functional brain laterality for sequential movements： Impact of transient practice

The impact of learning on brain functional laterality has not been systematically investigated. We employed an event-related functional magnetic resonance imaging combined with a delayed sequential movement task to investigate brain activation pattern and laterality during a transient practice in 12 subjects. Both hemispheres, involving motor areas and posterior parietal cortex, were engaged during motor preparation and execution, with larger activation volume in the left hemisphere than in the right. Activation volume in these regions significantly decreased after a transient practice, with more reduction in the right hemisphere resulting increase in left lateralization. The theoretical implications of these findings are discussed in relation to the physiological significance of brain functional laterality.     

慢性应激对小鼠空间学习记忆功能及海马和前额叶皮层BDNF表达的影响

采用多因素慢性应激动物模型,通过Morris水迷宫测试小鼠空间学习记忆能力;采用免疫组织化学方法检测脑源性神经营养因子（BDNF）在海马和前额叶皮层的表达．结果显示,与对照组相比,应激组小鼠的空间学习记忆能力明显下降（P〈0．01）;应激组小鼠海马CA1区、齿状回和前额叶皮层BDNF表达明显下降（P〈0．01）;停止应激后一周,应激组小鼠BDNF在各脑区的表达有一定恢复,但与对照组相比,仍有显著性差异（P〈0．05,P〈0．01）．结果表明,慢性应激导致小鼠空间学习记忆功能的损伤可能与BDNF表达的下调密切相关．     

菹草石芽萌发影响因子及其阶段性生物学积温研究

通过模拟实验研究了水位、光照、基质和絮凝剂对菹草石芽萌发及幼苗的影响,并探究了其幼苗去除顶芽再发新枝的阶段性生物学积温.结果表明:水位越深初始萌发越迟,全萌发所需天数浅水位中水位深水位,水位对幼苗形态特征有明显影响.光照下10d萌发率大于黑暗处理,湖泥中,有光和无光对石芽萌发影响并不明显,而在营养液中,有光明显促进石芽的萌发.光照下枝条数和根数大于黑暗处理.絮凝剂显著(P0.05)延迟石芽萌发,但不影响最终发芽率.去除顶叶的菹草幼苗萌发新枝的生物学有效积温为177.84日度,生物学零点温度为5.57℃,相同温度下随去除幼苗顶芽数增加再发新枝所需历期增长.     

Stress response genes protect against lethal effects of sleep deprivation in Drosophila

Sleep is controlled by two processes: a homeostatic drive that increases during waking and dissipates during sleep, and a circadian pacemaker that controls its timing. Although these two systems can operate independently, recent studies indicate a more intimate relationship. To study the interaction between homeostatic and circadian processes in Drosophila, we examined homeostasis in the canonical loss-of-function clock mutants period (per(01)), timeless (tim(01)), clock (Clk(jrk)) and cycle (cyc(01)). cyc(01) mutants showed a disproportionately large sleep rebound and died after 10 hours of sleep deprivation, although they were more resistant than other clock mutants to various stressors. Unlike other clock mutants, cyc(01) flies showed a reduced expression of heat-shock genes after sleep loss. However, activating heat-shock genes before sleep deprivation rescued cyc(01) flies from its lethal effects. Consistent with the protective effect of heat-shock genes, was the observation that flies carrying a mutation for the heat-shock protein Hsp83 (Hsp83(08445)) showed exaggerated homeostatic response and died after sleep deprivation. These data represent the first step in identifying the molecular mechanisms that constitute the sleep homeostat.     

Consolidation during sleep of perceptual learning of spoken language

Memory consolidation resulting from sleep has been seen broadly: in verbal list learning, spatial learning, and skill acquisition in visual and motor tasks. These tasks do not generalize across spatial locations or motor sequences, or to different stimuli in the same location. Although episodic rote learning constitutes a large part of any organism's learning, generalization is a hallmark of adaptive behaviour. In speech, the same phoneme often has different acoustic patterns depending on context. Training on a small set of words improves performance on novel words using the same phonemes but with different acoustic patterns, demonstrating perceptual generalization. Here we show a role of sleep in the consolidation of a naturalistic spoken-language learning task that produces generalization of phonological categories across different acoustic patterns. Recognition performance immediately after training showed a significant improvement that subsequently degraded over the span of a day's retention interval, but completely recovered following sleep. Thus, sleep facilitates the recovery and subsequent retention of material learned opportunistically at any time throughout the day. Performance recovery indicates that representations and mappings associated with generalization are refined and stabilized during sleep.     

STROOP测验在正常人和脑损伤患者应用结果的特征分析

目的 通过正常人群了解Stroop测验的结果是否存在性别、年龄和学历上存在差异;通过单纯额叶、颞叶和顶叶卒中的病人了解是Stroop测验可能的神经功能区域.方法 研究采用中文版Stroop测验和简易智能量表,数据处理采用SPSS13.0软件据包进行分析和处理.结果 正常人Stroop测验结果与性别无关（P〉0.05）,与年龄有关（P 〈0.05）,与教育程度有关（P 〈0.05）.卒中的病人按照左右半球损害分组无差异（P 〉0.05）,按照损害额叶、颞叶和顶叶分组无差异（P 〈0.05）.结论 正常人群Stroop测验结果与年龄和学历有关,无性别的差异.Stroop测验结果没有左右半球的差异,但是存在功能分区的差异,在额叶、颞叶和顶叶中,额叶的影响可能更大.     

Memory for places learned long ago is intact after hippocampal damage.

The hippocampus is part of a system of structures in the medial temporal lobe that are essential for memory. One influential view of hippocampal function emphasizes its role in the acquisition and retrieval of spatial knowledge. By this view, the hippocampus constructs and stores spatial maps and is therefore essential for learning and remembering places, including those learned about long ago. We tested a profoundly amnesic patient (E.P.), who has virtually complete bilateral damage to the hippocampus and extensive damage to adjacent structures in the medial temporal lobe. We asked him to recall the spatial layout of the region where he grew up, from which he moved away more than 50 years ago. E.P. performed as well as or better than age-matched control subjects who grew up in the same region and also moved away. In contrast, E.P. has no knowledge of his current neighbourhood, to which he moved after he became amnesic. Our results show that the medial temporal lobe is not the permanent repository of spatial maps, and support the view that the hippocampus and other structures in the medial temporal lobe are essential for the formation of long-term declarative memories, both spatial and non-spatial, but not for the retrieval of very remote memories, either spatial or non-spatial.     

Top-down signal from prefrontal cortex in executive control of memory retrieval.

Knowledge or experience is voluntarily recalled from memory by reactivation of the neural representations in the cerebral association cortex. In inferior temporal cortex, which serves as the storehouse of visual long-term memory, activation of mnemonic engrams through electric stimulation results in imagery recall in humans, and neurons can be dynamically activated by the necessity for memory recall in monkeys. Neuropsychological studies and previous split-brain experiments predicted that prefrontal cortex exerts executive control upon inferior temporal cortex in memory retrieval; however, no neuronal correlate of this process has ever been detected. Here we show evidence of the top-down signal from prefrontal cortex. In the absence of bottom-up visual inputs, single inferior temporal neurons were activated by the top-down signal, which conveyed information on semantic categorization imposed by visual stimulus-stimulus association. Behavioural performance was severely impaired with loss of the top-down signal. Control experiments confirmed that the signal was transmitted not through a subcortical but through a fronto-temporal cortical pathway. Thus, feedback projections from prefrontal cortex to the posterior association cortex appear to serve the executive control of voluntary recall.     

Improved auditory spatial tuning in blind humans.

Despite reports of improved auditory discrimination capabilities in blind humans and visually deprived animals, there is no general agreement as to the nature or pervasiveness of such compensatory sensory enhancements. Neuroimaging studies have pointed out differences in cerebral organization between blind and sighted humans, but the relationship between these altered cortical activation patterns and auditory sensory acuity remains unclear. Here we compare behavioural and electrophysiological indices of spatial tuning within central and peripheral auditory space in congenitally blind and normally sighted but blindfolded adults to test the hypothesis (raised by earlier studies of the effects of auditory deprivation on visual processing) that the effects of visual deprivation might be more pronounced for processing peripheral sounds. We find that blind participants displayed localization abilities that were superior to those of sighted controls, but only when attending to sounds in peripheral auditory space. Electrophysiological recordings obtained at the same time revealed sharper tuning of early spatial attention mechanisms in the blind subjects. Differences in the scalp distribution of brain electrical activity between the two groups suggest a compensatory reorganization of brain areas in the blind that may contribute to the improved spatial resolution for peripheral sound sources.     

枳菊解郁汤对抑郁模型小鼠空间学习记忆及脑内bFGF的影响

目的：探讨枳菊解郁汤对抑郁模型小鼠空间学习记忆的影响及其机制。方法：采用多因素慢性不可预知应激源建立抑郁动物模型,并给予动物不同剂量枳菊解郁汤。通过Morris水迷宫实验,检测各组小鼠空间学习记忆能力的变化;采用免疫组织化学方法检测碱性成纤维细胞生长因子（bFGF）在脑内的表达。结果：抑郁模型组小鼠空间学习记忆能力明显下降（P〈0．05）;bFGF在前脑皮层和海马CA1,CA3及DG区的表达明显降低（P〈0．05）;与模型组小鼠相比,枳菊解郁汤中剂量组空间学习记忆能力明显增强（P〈0．05）;bFGF在海马的CA1、CA3和DG区及前脑皮层的表达明显增加（P〈0．05）。结论：枳菊解郁汤的抗抑郁作用可能与海马和前脑皮层bFGF表达的上调有关。     

冥想加工性别差异的神经机制 ——来自ERP的证据

采用事件相关电位(ERP)技术,记录52名大学生被试在听(正性和负性)冥想指导语的脑电波,探索冥想加工过程的神经机制与性别差异.以固定频率的声音作为线索诱发N2和P3成分,这2个成分作为探究刺激差异和注意力资源调配的标记分别在160 ms和240 ms的时间上观察到.结果表明:在正性冥想条件下,在前额叶皮层(PFC)中...     

Optogenetic stimulation of a hippocampal engram activates fear memory recall

A specific memory is thought to be encoded by a sparse population of neurons. These neurons can be tagged during learning for subsequent identification and manipulation. Moreover, their ablation or inactivation results in reduced memory expression, suggesting their necessity in mnemonic processes. However, the question of sufficiency remains: it is unclear whether it is possible to elicit the behavioural output of a specific memory by directly activating a population of neurons that was active during learning. Here we show in mice that optogenetic reactivation of hippocampal neurons activated during fear conditioning is sufficient to induce freezing behaviour. We labelled a population of hippocampal dentate gyrus neurons activated during fear learning with channelrhodopsin-2 (ChR2) and later optically reactivated these neurons in a different context. The mice showed increased freezing only upon light stimulation, indicating light-induced fear memory recall. This freezing was not detected in non-fear-conditioned mice expressing ChR2 in a similar proportion of cells, nor in fear-conditioned mice with cells labelled by enhanced yellow fluorescent protein instead of ChR2. Finally, activation of cells labelled in a context not associated with fear did not evoke freezing in mice that were previously fear conditioned in a different context, suggesting that light-induced fear memory recall is context specific. Together, our findings indicate that activating a sparse but specific ensemble of hippocampal neurons that contribute to a memory engram is sufficient for the recall of that memory. Moreover, our experimental approach offers a general method of mapping cellular populations bearing memory engrams.     

苦参碱减轻糖氧剥夺复糖复氧对大鼠脑微血管内皮细胞损伤

为了研究苦参碱对脑缺血再灌注损伤的保护作用,实验通过离体培养鼠脑微血管内皮细胞,采用糖氧剥夺复糖复氧的模型,体外模拟脑缺血再灌注对脑血管内皮的损伤,研究苦参碱对内皮细胞的保护作用.苦参碱减轻糖氧剥夺复糖复氧对脑微血管内皮细胞的损伤,提高内皮细胞的生存率,同时增加损伤细胞线粒体ATP的生成.因此,苦参碱对糖氧剥夺复糖复氧损伤血管内皮细胞具有保护作用.