Orientation Selectivity
Mostrando 1-12 de 54 artigos, teses e dissertações.
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1. GABA-induced inactivation of Cebus apella V2 neurons: effects on orientation tuning and direction selectivity
We investigated the GABA-induced inactivation of V2 neurons and terminals on the receptive field properties of this area in an anesthetized and paralyzedCebus apella monkey. Extracellular single-unit activity was recorded using tungsten microelectrodes in a monkey before and after pressure-injection of a 0.25 or 0.5 M GABA solution. The visual stimulus consi
Braz J Med Biol Res. Publicado em: 22/07/2013
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2. Target-directed catalytic metallodrugs
Most drugs function by binding reversibly to specific biological targets, and therapeutic effects generally require saturation of these targets. One means of decreasing required drug concentrations is incorporation of reactive metal centers that elicit irreversible modification of targets. A common approach has been the design of artificial proteases/nucleas
Braz J Med Biol Res. Publicado em: 02/07/2013
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3. A RE-READING OF THE BRAZILIAN PENAL LAW IN THE PARADIGM OF THE DEMOCRATIC STATE / A RELEITURA DO DIREITO PENAL BRASILEIRO NO PARADIGMA DO ESTADO DEMOCRÁTICO DE DIREITO
The real operationality of the criminal system highlights a broad system of social control and pressure over popular classes, in favor of the politic and economic elites and in order to facilitate the reproduction of the hierarchized, verticalized and disciplined power relations which are inherent to the capitalist model, translating its individualist and ex
Publicado em: 2008
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4. O Processo de revisão do benefício de prestação continuada-BPC: uma lógica de exclusão ou inclusão social
This research comprises a study about the social assessment performed by the Social Worker in the review process of the Benefit of Continued Installment. The Benefit of Continued Installment was implemented in 1996 and guarantees a minimum salary to the deficiency person and to an elder with sixty five years or more and that proves not to have ways to suppor
Publicado em: 2006
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5. Modelação de fenômenos de plasticidade rápida no sistema visual de mamíferos / Modeling Fast Plasticity Phenomena in the Mammalian Primary Visual Cortex
Neurônios do córtex visual primário (V1) são seletivos à orientação, direção e freqüência espacial de estímulos apresentados em seus campos receptivos. Os últimos 40 anos acumularam uma quantidade considerável de teorias e dados sobre o processamento cortical de seletividade. Apesar disso, um consenso sobre os mecanismos que geram preferência
Publicado em: 2006
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6. The analysis of Alfvén wave antenna implementation in the ETE spherical tokamak
The preliminary design study of the Alfvén wave system for the ETE spherical tokamak is presented. The main objective of the proposed RF system is generation of travelling Alfvén waves, which can be used for the study of the non-inductive current drive and the plasma heating in a wide range of operational regimes, which are specific for tokamaks with small
Brazilian Journal of Physics. Publicado em: 2004-12
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7. Modelação do processamento neuronal primário no sistema visual de mamíferos. / Modelling the primary neural processing in mammal s visual system.
Since the discovery of the receptive field properties of cortical neurons in the primary visual cortex, their organization has been studied with many methods ranging from electrophysiology and optical imaging to computational neuroscience. Few models have been capable of showing ocularity and orientation selectivity simultaneously. A large-scale computationa
Publicado em: 2001
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8. A neuronal network model of macaque primary visual cortex (V1): Orientation selectivity and dynamics in the input layer 4Cα
In this paper, we offer an explanation for how selectivity for orientation could be produced by a model with circuitry that is based on the anatomy of V1 cortex. It is a network model of layer 4Cα in macaque primary visual cortex (area V1). The model consists of a large number of integrate-and-fire conductance-based point neurons, both excitatory and i
The National Academy of Sciences.
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9. A linear model fails to predict orientation selectivity of cells in the cat visual cortex.
1. Postsynaptic potentials (PSPs) evoked by visual stimulation in simple cells in the cat visual cortex were recorded using in vivo whole-cell technique. Responses to small spots of light presented at different positions over the receptive field and responses to elongated bars of different orientations centred on the receptive field were recorded. 2. To test
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10. Mechanisms underlying orientation selectivity of neurons in the primary visual cortex of the macaque.
1. Effects of blocking intracortical inhibition by microiontophoretic administration of bicuculline methiodide (BMI), a selective antagonist for GABAA receptors, on orientation selectivity of 109 neurones were studied in the primary visual cortex (V1) of anaesthetized and paralysed monkeys. 2. The averaged orientation tuning of visual responses of cells was
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11. The relationship of receptive field properties to the dendritic shape of neurones in the cat striate cortex.
In this study, we examined the hypothesis that some features of the receptive fields of cortical neurones are determined by the extent to which their dendrites can sample from different parts of the visual field representation on the cortex. In particular, the orientation selectivity and size of the receptive fields of cortical neurones were examined for the
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12. Formation of receptive fields in realistic visual environments according to the Bienenstock, Cooper, and Munro (BCM) theory.
The Bienenstock, Cooper, and Munro (BCM) theory of synaptic plasticity has successfully reproduced the development of orientation selectivity and ocular dominance in kitten visual cortex in normal, as well as deprived, visual environments. To better compare the consequences of this theory with experiment, previous abstractions of the visual environment are r