63 research outputs found

    Sexual dimorphism of medium-sized neurons with spines in human nucleus accumbens

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    The nucleus accumbens is a limbic nucleus, representing part of the striatum body, and together with the caudate nucleus and putamen, it lies on the septum. The aim of this study was to examine morphological sexual dimorphism in spine density and also to undertake an immunohistochemical study of expression for estrogen and progesterone receptors in the medium-sized neurons in the nucleus accumbens. The research was conducted on twenty human brains of persons of both sexes, between the age of 20-75 years. The Golgi method was applied to determine the types and subtypes of neurons, morphologies of soma, dendrites and axons, as well as the relations between the cells and glial elements. The following were quantitatively examined: the maximum diameter of the neurons, the minimal diameter of the neurons, and the total length of the dendrites. The expression of receptors for estrogen and progesterone, their distribution and intensity were defined immunohistochemically. The parameters of the bodies of neurons in the shell and core of the nucleus accumbens were studied in both men and women. No statistically significant differences were found. Examination of the spine density showed statistical significance in terms of a higher density of spines in women. Immunohistochemically, in the female brain estrogen expression is diffusely spread in a large number of neurons; it is extra nuclear, of granular appearance and high intensity. In the male brain, expression of estrogen is visible and distributed over about one half of different types of neurons; it is extra nuclear, of granular appearance, mostly of middle and low staining intensity. Expression of progesterone in the female brain was very discreet and on a very small number of neurons; it was extra nuclear and with a weak staining intensity. Expression of progesterone in the male brain was distributed on a small number of neurons. It had a granular appearance, it was extra nuclear, with a very low staining intensity. Our results show differences in the morphology as well as expression of receptors for estrogen and progesterone on medium-sized neurons with spines in the nucleus accumbens of men and women

    Anthropometric study of the facial index in the population of Central Serbia

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    The aim of this study was to determine the craniofacial parameters in the population of the central part of Serbia. The research was conducted on 700 persons (360 males and 340 females), aged 18-65 years, selected randomly. The measured parameters were morphological facial height and breadth. The standard spreading caliper with scale was used for the measurement of facial parameters. There were significant differences in the facial parameters of male compared to female subjects in all observed parameters. The mean value of the morphological facial height in the study population was 116.8 mm ± 7.28, maximum facial breadth 124.12 mm ± 8.44, while the mean value of the total facial index was 93.68 ± 6.86. The total facial index was calculated according to the formula and the obtained results were analyzed statistically using the t-test. The dominant phenotype in the studied population was leptoprosopic. The data obtained in our study may be useful in anthropological research, forensics, genetic research, as well as in medical clinical practice

    Atypical Balance between Occipital and Fronto-Parietal Activation for Visual Shape Extraction in Dyslexia

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    Reading requires the extraction of letter shapes from a complex background of text, and an impairment in visual shape extraction would cause difficulty in reading. To investigate the neural mechanisms of visual shape extraction in dyslexia, we used functional magnetic resonance imaging (fMRI) to examine brain activation while adults with or without dyslexia responded to the change of an arrow’s direction in a complex, relative to a simple, visual background. In comparison to adults with typical reading ability, adults with dyslexia exhibited opposite patterns of atypical activation: decreased activation in occipital visual areas associated with visual perception, and increased activation in frontal and parietal regions associated with visual attention. These findings indicate that dyslexia involves atypical brain organization for fundamental processes of visual shape extraction even when reading is not involved. Overengagement in higher-order association cortices, required to compensate for underengagment in lower-order visual cortices, may result in competition for top-down attentional resources helpful for fluent reading.Ellison Medical FoundationMartin Richmond Memorial FundNational Institutes of Health (U.S.). (Grant UL1RR025758)National Institutes of Health (U.S.). (Grant F32EY014750-01)MIT Class of 1976 (Funds for Dyslexia Research

    The Human Connectome Project's neuroimaging approach

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    Noninvasive human neuroimaging has yielded many discoveries about the brain. Numerous methodological advances have also occurred, though inertia has slowed their adoption. This paper presents an integrated approach to data acquisition, analysis and sharing that builds upon recent advances, particularly from the Human Connectome Project (HCP). The 'HCP-style' paradigm has seven core tenets: (i) collect multimodal imaging data from many subjects; (ii) acquire data at high spatial and temporal resolution; (iii) preprocess data to minimize distortions, blurring and temporal artifacts; (iv) represent data using the natural geometry of cortical and subcortical structures; (v) accurately align corresponding brain areas across subjects and studies; (vi) analyze data using neurobiologically accurate brain parcellations; and (vii) share published data via user-friendly databases. We illustrate the HCP-style paradigm using existing HCP data sets and provide guidance for future research. Widespread adoption of this paradigm should accelerate progress in understanding the brain in health and disease

    Cytoarchitectonic mapping of the human dorsal extrastriate cortex

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    The dorsal visual stream consists of several functionally specialized areas, but most of their cytoarchitectonic correlates have not yet been identified in the human brain. The cortex adjacent to Brodmann area 18/V2 was therefore analyzed in serial sections of ten human post-mortem brains using morphometrical and multivariate statistical analyses for the definition of areal borders. Two previously unknown cytoarchitectonic areas (hOc3d, hOc4d) were detected. They occupy the medial and, to a smaller extent, lateral surface of the occipital lobe. The larger area, hOc3d, is located dorso-lateral to area V2 in the region of superior and transverse occipital, as well as parieto-occipital sulci. Area hOc4d was identified rostral to hOc3d; it differed from the latter by larger pyramidal cells in lower layer III, thinner layers V and VI, and a sharp cortex-white-matter borderline. The delineated areas were superimposed in the anatomical MNI space, and probabilistic maps were calculated. They show a relatively high intersubject variability in volume and position. Based on their location and neighborhood relationship, areas hOc3d and hOc4d are putative anatomical substrates of functionally defined areas V3d and V3a, a hypothesis that can now be tested by comparing probabilistic cytoarchitectonic maps and activation studies of the living human brain

    Reference delineations of Area hOc5 (LOC) in individual sections of the BigBrain

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    This dataset contains cytoarchitectonic maps of area hOc5 (LOC) in the BigBrain. The mappings were created using multivariate statistical image analysis, applied to GLI-images of coronal histological sections of 1 micron resolution. Mappings are available on 21 sections of the occipital lobe of the BigBrain and have been transformed to the 3D reconstructed BigBrain space. For this brain area, a highly detailed 3D map has been computed based on automatic delineations on every histological section from a novel Deep Learning algorithm. This dataset can be accessed here: [Ultrahigh resolution 3D cytoarchitectonic map of Area hOc5 (LOC) created by a Deep-Learning assisted workflow](https://kg.ebrains.eu/search/live/minds/core/dataset/v1.0.0/ea8fb74b-0ecc-4801-9522-b4c2cb2a2a5c) This ultrahigh resolution 3D cytoarchitectonic map of Area hOc5 (LOC) can be explored in the HBP interactive Atlas Viewer
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