共查询到20条相似文献，搜索用时 609 毫秒
1.
目的 探讨灰质异位病理学诊断的客观依据。方法 分析17例灰质异位手术切除标本病理及临床资料,辅以免疫组化方法,计数灰质异位灶中神经元的数量和类型。结果 本组病例中灰质异位术前MRI确诊为3例,其余14例（82.4%,14/17）均依靠镜下诊断。大体改变有三型：（1）白质中孤立的皮质样结节;（2）位于皮质下、呈结节状或舌状与皮质相连;（3）大脑皮层增厚,皮白质分界不清。镜下部分灰质异位结节边界清,结节中神经元排列紊乱,无极向,无正常皮质分层结构;神经元可表现退变、坏死、形态不成熟;免疫组化GFAP可显示部分灰质异位结节的轮廓,神经元核抗原（neuronal nuclei,NeuN）、微管相关蛋白2,（microtubule associated protein-2,MAP-2）染色显示神经元数量减少且其中不成熟神经元比例增高,差异有显著统计学意义（t=-3.66,P<0.01）。结论 灰质异位病变范围广泛时可于影像学检测中发现,但多数的灰质异位诊断仍需依靠病理组织学确诊,免疫组化GFAP有利于观察灰质异位灶形态,NeuN和Map-2强阳性细胞计数能为灰质异位诊断提供客观依据。 相似文献
2.
To investigate whether the temporal cortex of a nonprimate species contains cells responsive to the sight of faces, a study was made in conscious sheep of the responses of neurons in this brain region to the sight of faces. Of 561 cells from which responses were recorded, 40 responded preferentially to faces. Different categories of these cells were influenced by dominance (presumably indicated by the presence and size of horns), breed and familiarity, and threatening faces such as those of humans and dogs. These results demonstrate that cells that respond preferentially to faces are present in the temporal cortex of a nonprimate species, and that the responses of these cells are influenced by factors relevant to social interaction. 相似文献
3.
Genes and social behavior 总被引：3，自引：0，他引：3
What genes and regulatory sequences contribute to the organization and functioning of neural circuits and molecular pathways in the brain that support social behavior? How does social experience interact with information in the genome to modulate brain activity? Here, we address these questions by highlighting progress that has been made in identifying and understanding two key "vectors of influence" that link genes, the brain, and social behavior: (i) Social information alters gene expression in the brain to influence behavior, and (ii) genetic variation influences brain function and social behavior. We also discuss how evolutionary changes in genomic elements influence social behavior and outline prospects for a systems biology of social behavior. 相似文献
4.
Silk JB 《Science (New York, N.Y.)》2007,317(5843):1347-1351
There is much interest in the evolutionary forces that favored the evolution of large brains in the primate order. The social brain hypothesis posits that selection has favored larger brains and more complex cognitive capacities as a means to cope with the challenges of social life. The hypothesis is supported by evidence that shows that group size is linked to various measures of brain size. But it has not been clear how cognitive complexity confers fitness advantages on individuals. Research in the field and laboratory shows that sophisticated social cognition underlies social behavior in primate groups. Moreover, a growing body of evidence suggests that the quality of social relationships has measurable fitness consequences for individuals. 相似文献
5.
Object recognition is challenging because each object produces myriad retinal images. Responses of neurons from the inferior temporal cortex (IT) are selective to different objects, yet tolerant ("invariant") to changes in object position, scale, and pose. How does the brain construct this neuronal tolerance? We report a form of neuronal learning that suggests the underlying solution. Targeted alteration of the natural temporal contiguity of visual experience caused specific changes in IT position tolerance. This unsupervised temporal slowness learning (UTL) was substantial, increased with experience, and was significant in single IT neurons after just 1 hour. Together with previous theoretical work and human object perception experiments, we speculate that UTL may reflect the mechanism by which the visual stream builds and maintains tolerant object representations. 相似文献
6.
目的 利用颅脑磁共振图像研究阿尔茨海默病(AD)患者脑灰质体积的改变.方法 利用DARTEL方法对11例AD患者(AD组)和11例健康对照者(HC组)的三维颅脑磁共振图像进行预处理,并对两组数据的全脑灰质进行基于体素的统计学分析.结果 与HC组比较,AD组的双侧海马、海马旁回、杏仁核、颞上回、颞中回、尾状核、豆状核、岛叶、小脑脚等结构灰质体积明显萎缩,差异有统计学意义(FDR校正,P＜0.05,体素≥50).结论 基于体素的形态学测量能够显示AD患者的脑灰质结构萎缩情况,有助于AD的早期诊断和病情监测. 相似文献
7.
Size-dependent development of the hydrogen bond network structure in large sized clusters of protonated water, H+(H2O)n (n = 4 to 27), was probed by infrared spectroscopy of OH stretches. Spectral changes with cluster size demonstrate that the chain structures at small sizes (n less, similar 10) develop into two-dimensional net structures (approximately 10 < n < 21), and then into nanometer-scaled cages (n >/= 21). 相似文献
8.
城乡统筹发展中农村人口流动的复杂网络分析——以南磨房乡为例 总被引：1，自引：0，他引：1
北京市朝阳区城乡统筹发展的目标是实现农民身份市民化,其间农村人口的流动包括户籍转变和农民居住空间从分散的自然村转向城镇的流动。采用社会网络的方法分别从密度、中心性和凝聚子群三个角度来分析南磨房乡村民的关系网络,找出网络中存在的派系和核心人物,通过指标的测度,分析解决农村人口流动中出现的问题。 相似文献
9.
调查4个仓库火腿节肢动物群落组成及结构的变化,应用群落特征参数、主分量分析和灰色系统分析方法分析昆虫群落特征及其在时间过程中的主导因素和时间格局以及与环境的关系。研究结果表明,火腿发酵时间的长短是影响火腿节肢动物群落结构及动态的主要因子,火腿发酵时间延长,火腿节肢动物群落多样性指数、丰富度指数及均匀度指数降低,而优势度指数和优势集中性指数则升高,主导宣威火腿节肢动物群落结构变化的主要特征指数是均匀度指数,同时多样性和丰富度在群落结构中也有较重要的作用,影响群落结构的环境因子主要是相对湿度。 相似文献
10.
Does rejection hurt? An FMRI study of social exclusion 总被引：1，自引：0，他引：1
A neuroimaging study examined the neural correlates of social exclusion and tested the hypothesis that the brain bases of social pain are similar to those of physical pain. Participants were scanned while playing a virtual ball-tossing game in which they were ultimately excluded. Paralleling results from physical pain studies, the anterior cingulate cortex (ACC) was more active during exclusion than during inclusion and correlated positively with self-reported distress. Right ventral prefrontal cortex (RVPFC) was active during exclusion and correlated negatively with self-reported distress. ACC changes mediated the RVPFC-distress correlation, suggesting that RVPFC regulates the distress of social exclusion by disrupting ACC activity. 相似文献
11.
《东北农业大学学报(英文版)》2016,(3):39-46
Human depression patients often show abnormal pupillary reflex with morphological changes in hippo campus and prefrontal cortex.This study aimed to find the relationship between the prolonged pupillary light reflex(PLR) which had been shown by confined sows with chronic stress or depression and morphological changes in brain,in order to provide theoretical basis for that the confined environment should lead to sows' depression.A total of 637 sows of Durac,Landrace and Large White breeds with various parities were observed,and the pupil light reflex(PLR) was measured and the actual pupillary light reflex time(PLRT) were recorded.All the PLRTs were grouped based on the results of confidence interval:t10%as group A,5%t10%as group B,1%t5%as group C and t1%as group D.Three individuals were randomly selected from each group(12 sows in total) and the white tissues of hippocampus and the prefrontal cortex were prepared for HS staining slices(three slices/per tissue) for observation on tissue structure and pathological changes with high magnification(400X) of electronic microscope.The results showed that in group A(t10%) pathological change was found in hippocampus,however,as PLRT increased from group B to group D,pathological changes in hippocampus tissues tended to be deteriorated with the increase of inflammatory cells and nuclear pyknosis phenomena.The same as those shown in hippocampus as the increasing of PLRT from groups A to D,more inflammatory cells appeared in prefrontal cortex for groups B and D.The results suggested that the tissue lesions of hippocampus and prefrontal cortex of the confined sows with prolonged PLRT might be the results of chronic stress or depression. 相似文献
12.
河北省农村居民消费结构的灰色关联与趋势预测分析 总被引：1，自引：0，他引：1
为优化农村居民消费结构,选取食品、衣着、居住、家用设备、医疗保健、交通与通讯、文教娱乐和其他8个方面人均生活消费支出数据,在聚类分析的基础上,运用灰色关联分析模型和GM(1,1)预测模型对河北省农村居民消费结构变动情况进行了灰色关联分析.结果表明:农村居民消费结构有所改善,农村居民消费结构从生存资料为主开始向享受资料和... 相似文献
13.
PENFIELD W 《Science (New York, N.Y.)》1959,129(3365):1719-1725
The interpretive cortex has in it a mechanism for instant reactivation of the detailed record of the past. It has a mechanism also for the production of interpretive signals. Such signals could only be significant if past records are scanned and relevant experiences are selected for comparison with present experience. This is a subconscious process. But it may well be that this scanning of past experience and selection from it also renders the relevant past available for conscious consideration as well. Thus, the individual may refer to the record as he employs other circuits of the brain. Access to the record of the past seems to be as readily available from the temporal cortex of one side as from that of the other. Auditory illusions (or interpretations of the distance, loudness, or tempo of sounds) have been produced by stimulation of the temporal cortex of either side. The same is true of illusional emotions, such as fear and disgust. But, on the contrary, visual illusions (interpretations of the distance, dimension, erectness, and tempo of things seen) are only produced by stimulation of the temporal cortex on the nondominant (normally, right) side of the brain. Illusions of recognition, such as familiarity or strangeness, were also elicited only from the nondominant side, except in one case. 相似文献
14.
Cortical afferents to the entorhinal cortex of the Rhesus monkey 总被引：5，自引：0，他引：5
Although the entorhinal cortex is a major contributor of afferents to the hippocampus and dentate gyrus, knowledge of its own afferents has been vague. Regions of both the frontal and temporal lobes were found to contribute afferents to this region of the brain. These afferents form probable multisynaptic links in pathways connecting the classical sensory areas of the cortex and the limbic system. 相似文献
15.
DNA is too unstable to be preserved during fossilization, but it still seems possible to infer the genome content of fossils because in every group of organisms investigated cell size is proportional to quantity of DNA. Accordingly, information on macroevolutionary trends in genome size through millions of years is potentially available. This survey of inferred variation in genome content in fossils is based on measurements of epithelial cells in extinct conodonts over a period of 270 million years. Why genome size varies so widely amongst living organisms is a subject of continuing debate. Paleontology offers a distinct temporal perspective, but lack of data on conodont paleoecology make the proposed adaptive explanations for genome variation difficult to test. 相似文献
16.
There is growing evidence that the neuropeptides oxytocin and vasopressin modulate complex social behavior and social cognition. These ancient neuropeptides display a marked conservation in gene structure and expression, yet diversity in the genetic regulation of their receptors seems to underlie natural variation in social behavior, both between and within species. Human studies are beginning to explore the roles of these neuropeptides in social cognition and behavior and suggest that variation in the genes encoding their receptors may contribute to variation in human social behavior by altering brain function. Understanding the neurobiology and neurogenetics of social cognition and behavior has important implications, both clinically and for society. 相似文献
17.
Neuronal diversity and temporal dynamics: the unity of hippocampal circuit operations 总被引：1，自引：0，他引：1
In the cerebral cortex, diverse types of neurons form intricate circuits and cooperate in time for the processing and storage of information. Recent advances reveal a spatiotemporal division of labor in cortical circuits, as exemplified in the CA1 hippocampal area. In particular, distinct GABAergic (gamma-aminobutyric acid-releasing) cell types subdivide the surface of pyramidal cells and act in discrete time windows, either on the same or on different subcellular compartments. They also interact with glutamatergic pyramidal cell inputs in a domain-specific manner and support synaptic temporal dynamics, network oscillations, selection of cell assemblies, and the implementation of brain states. The spatiotemporal specializations in cortical circuits reveal that cellular diversity and temporal dynamics coemerged during evolution, providing a basis for cognitive behavior. 相似文献
18.
A fossil from the Early Jurassic (Sinemurian, approximately 195 million years ago) represents a new lineage of mammaliaforms, the extinct groups more closely related to the living mammals than to nonmammaliaform cynodonts. It has an enlarged cranial cavity, but no postdentary trough on the mandible, indicating separation of the middle ear bones from the mandible. This extends the earliest record of these crucial mammalian features by some 45 million years and suggests that separation of the middle ear bones from the mandible and the expanded brain vault could be correlated. It shows that several key mammalian evolutionary innovations in the ear region, the temporomandibular joint, and the brain vault evolved incrementally through mammaliaform evolution and long before the differentiation of the living mammal groups. With an estimated body weight of only 2 grams, its coexistence with other larger mammaliaforms with similar "triconodont-like" teeth for insectivory within the same fauna suggests a great trophic diversity within the mammaliaform insectivore feeding guild, as inferred from the range of body sizes. 相似文献
19.
The periaqueductal gray matter mediates opiate-induced immunosuppression 总被引：14，自引：0，他引：14
The periaqueductal gray matter of the mesencephalon (PAG) subserves a variety of diverse autonomic functions and also appears to be a site for opiate action in the induction of immunosuppression. Microinjections of morphine into the PAG, but not into other opiate receptor-containing neuroanatomical sites, result in a rapid suppression of natural killer (NK) cell activity. The NK cell suppression can be blocked by prior peripheral administration of the opiate antagonist naltrexone. These findings demonstrate that certain central actions of opiates that produce changes in NK cell function are mediated through opiate receptors in the PAG and identify a brain region involved in opiate regulation of immune function. 相似文献
20.
A Discussion on Possible Indicators Related to Genetic Structure Changes in Plant Germplasm Conservation 总被引：1，自引：0，他引：1
GAI Jun-yi 《中国农业科学(英文版)》2004,3(11)
The purpose of the present paper is to study and develop indicators and procedures for the evaluation of genetic structure changes in germplasm conservation due to social and natural environment reasons.Some basic concepts in germplasm study were introduced at first. Then, six kinds of indicators for genetic diversity as a measure of genetic potential of a germplasm collection were presented, i.e.,numbers of different entities at certain level, evenness of the entity distribution, genetic similarityand genetic distance, genetic variance and genetic coefficient of variation, multivariate genetic variation indices, and coefficient of parentage. It was pointed out that genetic dispersion did not provide a complete concept of genetic diversity if without any information from genetic richness. Based on the above, the indicators for genetic erosion as the genetic structure changes of germplasm conservation due to social reasons, the indicators of genetic vulnerability as the genetic structure changes of germplasm conservation due to environmental stresses, the measurement of genetic drift and genetic shift as the genetic structure changes of germplasm collection during reproduction or seed increase were reviewed and developed. Furthermore, the estimation procedures of the indicators by using molecular markers were suggested. Finally, the case studies on suitable conservation sample size of self-pollinated and open-pollinated populations were given for reference. 相似文献