73 research outputs found

    Mesoscale cortical dynamics reflect the interaction of sensory evidence and temporal expectation during perceptual decision-making

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    How sensory evidence is transformed across multiple brain regions to influence behavior remains poorly understood. We trained mice in a visual change detection task designed to separate the covert antecedents of choices from activity associated with their execution. Wide-field calcium imaging across the dorsal cortex revealed fundamentally different dynamics of activity underlying these processes. Although signals related to execution of choice were widespread, fluctuations in sensory evidence in the absence of overt motor responses triggered a confined activity cascade, beginning with transient modulation of visual cortex and followed by sustained recruitment of the secondary and primary motor cortex. Activation of the motor cortex by sensory evidence was modulated by animals’ expectation of when the stimulus was likely to change. These results reveal distinct activation timescales of specific cortical areas by sensory evidence during decision-making and show that recruitment of the motor cortex depends on the interaction of sensory evidence and temporal expectation

    PINP: a new method of tagging neuronal populations for identification during in vivo electrophysiological recording

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    Neural circuits are exquisitely organized, consisting of many different neuronal subpopulations. However, it is difficult to assess the functional roles of these subpopulations using conventional extracellular recording techniques because these techniques do not easily distinguish spikes from different neuronal populations. To overcome this limitation, we have developed PINP (Photostimulation-assisted Identification of Neuronal Populations), a method of tagging neuronal populations for identification during in vivo electrophysiological recording. The method is based on expressing the light-activated channel channelrhodopsin-2 (ChR2) to restricted neuronal subpopulations. ChR2-tagged neurons can be detected electrophysiologically in vivo since illumination of these neurons with a brief flash of blue light triggers a short latency reliable action potential. We demonstrate the feasibility of this technique by expressing ChR2 in distinct populations of cortical neurons using two different strategies. First, we labeled a subpopulation of cortical neurons-mainly fast-spiking interneurons-by using adeno-associated virus (AAV) to deliver ChR2 in a transgenic mouse line in which the expression of Cre recombinase was driven by the parvalbumin promoter. Second, we labeled subpopulations of excitatory neurons in the rat auditory cortex with ChR2 based on projection target by using herpes simplex virus 1 (HSV1), which is efficiently taken up by axons and transported retrogradely; we find that this latter population responds to acoustic stimulation differently from unlabeled neurons. Tagging neurons is a novel application of ChR2, used in this case to monitor activity instead of manipulating it. PINP can be readily extended to other populations of genetically identifiable neurons, and will provide a useful method for probing the functional role of different neuronal populations in vivo

    THE METHODOLOGY OF THE STUDY OF MEANINGFUL UNITS OF THE OFFICIAL DISCOURSE OF THE REPUBLICS – THE SUBJECTS OF THE RUSSIAN FEDERATION – ON THE ISSUES OF FORMING ALLRUSSIAN CIVIC IDENTITY

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    The article deals with the method of analyzing the discourse of the republics (subjects of the Russian Federation) on national policy and the formation of the All-Russian civic identity. The author notes the importance of analyzing the positions of the republics as national subjects of the Russian Federation on the interpretation of the concept of All-Russian civic identity, as well as its relationship with the Republican or ethnic identity. The authors emphasize the potential of content analysis as the main research method in this particular case, which is explained by the possibility of quantifying the degree of attention of the Republican authorities to the issue under consideration, as well as identifying the attitude of regional elites and the media to it. At the same time, there is a need to verify the results of content analysis using qualitative methods, such as an expert focus group interview. Based on the results  of approbation of the developed research toolkit, the authors put forward three hypotheses that need to be  tested in the course of further study of the official discourse of the republics – subjects of Russian Federation  on the stated problems

    Метастатическая карцинома Меркеля, осложненная на фоне иммуноонкологической терапии поперечным миелитом

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    Objective. To present a unique clinical case of metastatic lesions of the perirenal space, ureter and bladder in Merkel's carcinoma with the development of transverse myelitis against the background of immuno-oncological therapy.Matherial and methods. The modern states of issue in diagnose and treatment of metastatic Merkel's carcinoma within multidisciplinary approach based on the medical documentation and radiological examinations (CT, MRI) was analysed in this article.Results. The unique clinical case of metastatic Merkel's carcinoma complicated by transverse myelitis during immuno-oncological therapy according to MSCT and MRI examinations report was demonstrated.Conclusion. Radiological examinations such as MSCT, MRI, ultrasound and PET/CT needed for detection, assess the incidence of tumor (metastasis and staging) and treatment efficiency control because of the rare occurrence and insufficient knowledge of Merkel's carcinoma.Цель исследования: продемонстрировать уникальный клинический случай метастатического поражения околопочечного пространства, мочеточника и мочевого пузыря при карциноме Меркеля с развитием на фоне иммуноонкологической терапии поперечного миелита.Материал и методы. Проведен анализ современного состояния вопроса диагностики и лечения карциномы Меркеля в рамках мультидисциплинарного подхода на основании медицинской документации и лучевых исследований (МСКТ, МРТ) у пациента с данным заболеванием.Результаты. На основании данных лучевых исследований (МРТ, МСКТ) продемонстрирован уникальный клинический случай метастатической карциномы Меркеля, осложненной поперечным миелитом на фоне иммуноонкологической терапии.Заключение. С учетом редкой встречаемости и недостаточной изученности карциномы Меркеля методы лучевой диагностики ПЭТ/КТ, МСКТ, МРТ и УЗИ необходимы для выявления и оценки распространенности опухолевого процесса (выявление метастазов и стадирование), дальнейшего определения эффективности лечения

    Highly Luminescent Salts Containing Well-Shielded Lanthanide-Centered Complex Anions and Bulky Imidazolium Countercations

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    In this paper, we report on the syntheses, structures, and characterization of four molten salts containing imidazolium cations and europium(III)- or terbium(III)-centered complex anions. In the complex anions, the lanthanide centers are wrapped by four pseudodiketonate anionic ligands, which prevent them from contacting with high-frequency oscillators and allow them to show intense characteristic europium(III) or terbium(III) emission, small line widths, high color purity, high quantum yields (30−49%), and long decay times (\u3e2 ms)

    A new framework for cortico-striatal plasticity: behavioural theory meets In vitro data at the reinforcement-action interface

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    Operant learning requires that reinforcement signals interact with action representations at a suitable neural interface. Much evidence suggests that this occurs when phasic dopamine, acting as a reinforcement prediction error, gates plasticity at cortico-striatal synapses, and thereby changes the future likelihood of selecting the action(s) coded by striatal neurons. But this hypothesis faces serious challenges. First, cortico-striatal plasticity is inexplicably complex, depending on spike timing, dopamine level, and dopamine receptor type. Second, there is a credit assignment problem—action selection signals occur long before the consequent dopamine reinforcement signal. Third, the two types of striatal output neuron have apparently opposite effects on action selection. Whether these factors rule out the interface hypothesis and how they interact to produce reinforcement learning is unknown. We present a computational framework that addresses these challenges. We first predict the expected activity changes over an operant task for both types of action-coding striatal neuron, and show they co-operate to promote action selection in learning and compete to promote action suppression in extinction. Separately, we derive a complete model of dopamine and spike-timing dependent cortico-striatal plasticity from in vitro data. We then show this model produces the predicted activity changes necessary for learning and extinction in an operant task, a remarkable convergence of a bottom-up data-driven plasticity model with the top-down behavioural requirements of learning theory. Moreover, we show the complex dependencies of cortico-striatal plasticity are not only sufficient but necessary for learning and extinction. Validating the model, we show it can account for behavioural data describing extinction, renewal, and reacquisition, and replicate in vitro experimental data on cortico-striatal plasticity. By bridging the levels between the single synapse and behaviour, our model shows how striatum acts as the action-reinforcement interface

    Noninvasive optical inhibition with a red-shifted microbial rhodopsin

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    Optogenetic inhibition of the electrical activity of neurons enables the causal assessment of their contributions to brain functions. Red light penetrates deeper into tissue than other visible wavelengths. We present a red-shifted cruxhalorhodopsin, Jaws, derived from Haloarcula (Halobacterium) salinarum (strain Shark) and engineered to result in red light–induced photocurrents three times those of earlier silencers. Jaws exhibits robust inhibition of sensory-evoked neural activity in the cortex and results in strong light responses when used in retinas of retinitis pigmentosa model mice. We also demonstrate that Jaws can noninvasively mediate transcranial optical inhibition of neurons deep in the brains of awake mice. The noninvasive optogenetic inhibition opened up by Jaws enables a variety of important neuroscience experiments and offers a powerful general-use chloride pump for basic and applied neuroscience.McGovern Institute for Brain Research at MIT (Razin Fellowship)United States. Defense Advanced Research Projects Agency. Living Foundries Program (HR0011-12-C-0068)Harvard-MIT Joint Research Grants Program in Basic NeuroscienceHuman Frontier Science Program (Strasbourg, France)Institution of Engineering and Technology (A. F. Harvey Prize)McGovern Institute for Brain Research at MIT. Neurotechnology (MINT) ProgramNew York Stem Cell Foundation (Robertson Investigator Award)National Institutes of Health (U.S.) (New Innovator Award 1DP2OD002002)National Institute of General Medical Sciences (U.S.) (EUREKA Award 1R01NS075421)National Institutes of Health (U.S.) (Grant 1R01DA029639)National Institutes of Health (U.S.) (Grant 1RC1MH088182)National Institutes of Health (U.S.) (Grant 1R01NS067199)National Science Foundation (U.S.) (Career Award CBET 1053233)National Science Foundation (U.S.) (Grant EFRI0835878)National Science Foundation (U.S.) (Grant DMS0848804)Society for Neuroscience (Research Award for Innovation in Neuroscience)Wallace H. Coulter FoundationNational Institutes of Health (U.S.) (RO1 MH091220-01)Whitehall FoundationEsther A. & Joseph Klingenstein Fund, Inc.JPB FoundationPIIF FundingNational Institute of Mental Health (U.S.) (R01-MH102441-01)National Institutes of Health (U.S.) (DP2-OD-017366-01)Massachusetts Institute of Technology. Simons Center for the Social Brai

    Роль радионуклидной диагностики в комплексном обследовании ВИЧ-инфицированных пациентов с ишемической болезнью сердца

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    Cardiovascular disease is one of the most frequent cause of death globally. The greatest part is occupied by ischemic heart disease. HIV patients are composed to a higher risk of coronary heart disease.The purpose of this work is to evaluate the possibility of using molecular imaging methods in a comprehensive examination of patients with HIV infection and ischemic heart disease.Materials and methods. The survey group includes 32 patients with HIV infection. The comparison group consists of 25 age-matched patients with coronary heart disease and without HIV Infection. All patients were underwent myocardial perfusion scintigraphy using single photon emission computed tomography. Positron emission tomography with FDG were performed if necessary to assess the viability of the myocardium. The patients of the main group undergo diagnostic coronary angiography and standard set of laboratory and institutional diagnostic methods.Results. The results of which confirm the high efficiency of radionuclide diagnostic methods for detecting perfusion disorders, contractility and myocardial viability in patients with HIV infection even at an early stage. They can be recommended for using in a comprehensive examination of patients with HIV infection.Наиболее частой причиной смертности во всем мире являются сердечно-сосудистые заболевания, среди которых ведущее место занимает ишемическая болезнь сердца (ИБС). В группу с наиболее высоким риском развития ИБС входят пациенты с ВИЧ-инфекцией.Цель исследования: оценка возможности применения методов молекулярной визуализации в комплексном обследовании пациентов с ВИЧ-инфекцией и ИБС.Материал и методы. В группу обследования включено 32 пациента с ВИЧ-инфекцией, группу сравнения составили 25 сопоставимых по возрасту пациентов без ВИЧ-инфекции с ИБС. Всем пациентам проведена перфузионная сцинтиграфия миокарда (с помощью ОФЭКТ), ПЭТ/КТ сердца с ФДГ проводилась при необходимости оценки жизнеспособности миокарда в комплексе с диагностической коронароангиографией и стандартным набором лабораторно-инструментальных методов диагностики.Результаты. Полученные результаты подтверждают высокую эффективностью методов радионуклидной диагностики для выявления нарушений перфузии, сократимости и жизнеспособности миокарда у пациентов с ВИЧ-инфекцией даже на ранней стадии и могут быть рекомендованы к использованию в комплексном обследовании пациентов с ВИЧ-инфекцией

    GrassPlot - a database of multi-scale plant diversity in Palaearctic grasslands

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    GrassPlot is a collaborative vegetation-plot database organised by the Eurasian Dry Grassland Group (EDGG) and listed in the Global Index of Vegetation-Plot Databases (GIVD ID EU-00-003). GrassPlot collects plot records (releves) from grasslands and other open habitats of the Palaearctic biogeographic realm. It focuses on precisely delimited plots of eight standard grain sizes (0.0001; 0.001;... 1,000 m(2)) and on nested-plot series with at least four different grain sizes. The usage of GrassPlot is regulated through Bylaws that intend to balance the interests of data contributors and data users. The current version (v. 1.00) contains data for approximately 170,000 plots of different sizes and 2,800 nested-plot series. The key components are richness data and metadata. However, most included datasets also encompass compositional data. About 14,000 plots have near-complete records of terricolous bryophytes and lichens in addition to vascular plants. At present, GrassPlot contains data from 36 countries throughout the Palaearctic, spread across elevational gradients and major grassland types. GrassPlot with its multi-scale and multi-taxon focus complements the larger international vegetationplot databases, such as the European Vegetation Archive (EVA) and the global database " sPlot". Its main aim is to facilitate studies on the scale-and taxon-dependency of biodiversity patterns and drivers along macroecological gradients. GrassPlot is a dynamic database and will expand through new data collection coordinated by the elected Governing Board. We invite researchers with suitable data to join GrassPlot. Researchers with project ideas addressable with GrassPlot data are welcome to submit proposals to the Governing Board

    BIOTIC DIVERSITY OF KARELIA: CONDITIONS OF FORMATION, COMMUNITIES AND SPECIES

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    The monograph generalises vast data characterising the diversity of the biota in Russian Karelia. The data pool includes both materials of long-term studies, and new data collected in 1997–2000 within the Russian-Finnish project “Inventory and studies of biological diversity in Republic of Karelia”. The volume is composed of four interrelated chapters. Chapter one provides a detailed account of the climatic, geological, geomorphological, hydrological and soil conditions in which the regional biota has been forming. Chapter two describes and evaluates the diversity of forest, mire and meadow communities, and the third chapter details the terrestrial biota at the species level (vascular plants, mosses, aphyllophoroid fungi, lichens, mammals, birds, insects). A special section is devoted to the flora and fauna of aquatic ecosystems (algae, zooplankton, periphyton, macrozoobenthos, fishes). Wide use is made of various zoning approaches based on biodiversity-related criteria. Current status of the regional biota, including its diversity in protected areas, is analysed with elements of the human impact assessment. A concise glossary of the terms used is annexed. This is an unprecedentally multi-faceted review, at least for the taiga zone of European Russia. The volume offers extensive reference materials for researchers in a widest range of ecological and biological fields, including graduate and post-graduate students. The monograph is also available in Russian
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