37 research outputs found

    Local Signal Time-Series during Rest Used for Areal Boundary Mapping in Individual Human Brains

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    It is widely thought that resting state functional connectivity likely reflects functional interaction among brain areas and that different functional areas interact with different sets of brain areas. A method for mapping areal boundaries has been formulated based on the large-scale spatial characteristics of regional interaction revealed by resting state functional connectivity. In the present study, we present a novel analysis for areal boundary mapping that requires only the signal timecourses within a region of interest, without reference to the information from outside the region. The areal boundaries were generated by the novel analysis and were compared with those generated by the previously-established standard analysis. The boundaries were robust and reproducible across the two analyses, in two regions of interest tested. These results suggest that the information for areal boundaries is readily available inside the region of interest

    Bioavailable Trace Metals in Neurological Diseases

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    Medical treatment in Wilson’s disease includes chelators (d-penicillamine and trientine) or zinc salts that have to be maintain all the lifelong. This pharmacological treatment is categorised into two phases; the first being a de-coppering phase and the second a maintenance one. The best therapeutic approach remains controversial, as only a few non-controlled trials have compared these treatments. During the initial phase, progressive increase of chelators’ doses adjusted to exchangeable copper and urinary copper might help to avoid neurological deterioration. Liver transplantation is indicated in acute fulminant liver failure and decompensated cirrhosis; in cases of neurologic deterioration, it must be individually discussed. During the maintenance phase, the most important challenge is to obtain a good adherence to lifelong medical therapy. Neurodegenerative diseases that lead to a mislocalisation of iron can be caused by a culmination of localised overload (pro-oxidant siderosis) and localised deficiency (metabolic distress). A new therapeutic concept with conservative iron chelation rescues iron-overloaded neurons by scavenging labile iron and, by delivering this chelated metal to endogenous apo-transferrin, allows iron redistribution to avoid systemic loss of iron

    Visualizing the Human Subcortex Using Ultra-high Field Magnetic Resonance Imaging

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    Glutamate-receptor-mediated encoding and retrieval of paired-associate learning

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    Paired-associate learning is often used to examine episodic memory in humans (1). Animal models include the recall of foodcache locations by scrub jays (2) and sequential memory (3,4). Here we report a model in which rats encode, during successive sample trials, two paired associates (flavours of food and their spatial locations) and display better-than-chance recall of one item when cued by the other. In a first study, pairings of a particular foodstuff and its location were never repeated, so ensuring unique ‘what–where’ attributes. Blocking N-methyl-D-aspartate receptors in the hippocampus—crucial for the induction of certain forms of activity-dependent synaptic plasticity (5,6)— impaired memory encoding but had no effect on recall. Inactivating hippocampal neural activity by blocking a-amino-3- hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptors impaired both encoding and recall. In a second study, two paired associates were trained repeatedly over 8 weeks in new pairs, but blocking of hippocampal AMPA receptors did not affect their recall. Thus we conclude that unique what–where paired associates depend on encoding and retrieval within a hippocampal memory space (7,8) with consolidation of the memory traces representing repeated paired associates in circuits elsewhere
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