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| Registros recuperados: 585 | |
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| Sophie Dutheil; Jean Michel Brezun; Jacques Leonard; Michel Lacour; Brahim Tighilet. |
| Neurogenesis occurs in some regions of the adult mammalian brain and gives rise to neurons integrated into functional networks. In pathological or postlesional conditions, neurogenesis and astrogenesis can also occur, as demonstrated in the deafferented vestibular nuclei after unilateral vestibular neurectomy in the adult cat. Here we report that in cats infused with an antimitotic drug, cytosine-[beta]-D arabinofuranoside (AraC), the number of GAD67 and GFAP immunoreactive cells is increased, despite the total mitotic activity blockade observed in the deafferented vestibular nuclei after unilateral vestibular neurectomy. At the behavioral level, recovery of posturo-locomotor function was drastically delayed, and no alteration of the horizontal spontaneous... |
| Tipo: Manuscript |
Palavras-chave: Neuroscience. |
| Ano: 2009 |
URL: http://precedings.nature.com/documents/2957/version/1 |
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| Rodrick Wallace. |
| The Stanley Miller experiment suggests that amino acid-based life is ubiquitous in our universe, although its varieties are not likely to have followed the particular, highly contingent and path-dependent, evolutionary trajectory found on Earth. Are many alien organisms likely to be conscious in ways that we would recognize? Almost certainly. Will some develop high order technology? Less likely, but still fairly probable. If so, will we be able to communicate with them? Only on a basic level, and only with profound difficulty. The argument is fairly direct. |
| Tipo: Manuscript |
Palavras-chave: Ecology; Neuroscience; Bioinformatics; Evolutionary Biology. |
| Ano: 2011 |
URL: http://precedings.nature.com/documents/5286/version/2 |
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| Jong-Hoon Ahn; Yillbyung Lee. |
| Exploring representations is a fundamental step towards understanding vision. The visual system carries two types of information along separate pathways: One is about what it is and the other is about where it is. Initially, the what is represented by a pattern of activity that is distributed across millions of photoreceptors, whereas the where is 'implicitly' given as their retinotopic positions. Many computational theories of object recognition rely on such pixel-based representations, but they are insufficient to learn spatial information such as position and size due to the implicit encoding of the where information. 
Here we try transforming a retinal image of an object into its internal image via interchanging the... |
| Tipo: Manuscript |
Palavras-chave: Neuroscience. |
| Ano: 2008 |
URL: http://precedings.nature.com/documents/1686/version/1 |
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| Hansem Sohn; Sang-Hun Lee. |
| Behavioral studies on perceptual learning (PL) often attributed an improvement in task performance to an enhancement in sensory processing of stimuli. However, the framework of Bayesian inference suggests that perceptual improvements can arise from learning-induced changes either in a likelihood function or in a prior expectation for sensory input. We developed and adapted Bayesian observer models to long-term changes in interval timing (IT) performance by human subjects to assess relative contributions of the prior and likelihood to PL of IT.

While subjects were viewing a small bar that drifted for a while and disappeared, we estimated subjective time intervals ([DELTA]Ts) from subjects’ natural reactions to... |
| Tipo: Poster |
Palavras-chave: Neuroscience. |
| Ano: 2011 |
URL: http://precedings.nature.com/documents/5804/version/1 |
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| Grace Lee; Christopher A. Shaw. |
| Adult onset amyotrophic lateral sclerosis (ALS) arises due to progressive and irreversible functional deficits to the central nervous system, specifically the loss of motor neurons. Sporadic ALS causality is not well understood, but is almost certainly of multifactorial origin involving a combination of genetic and environmental factors. The discovery of endemic ALS in the native Chamorro population of Guam during the 1950s and the co-occurrence of parkinsonism and dementia in some patients led to searches for an environmental toxins that could be responsible. In the present paper, we report that an environmental neurotoxin enhances mutant superoxide dismutase (SOD)-induced spinal motor neuron death and pathology and induces motor axon abnormalities. These... |
| Tipo: Manuscript |
Palavras-chave: Neuroscience. |
| Ano: 2011 |
URL: http://precedings.nature.com/documents/6559/version/1 |
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| Robert Urbanczik; Walter Senn. |
| Population coding is widely regarded as a key mechanism for achieving reliable behavioral responses in the face of neuronal variability. But in standard reinforcement learning a flip-side becomes apparent. Learning slows down with increasing population size since the global reinforcement becomes less and less related to the performance of any single neuron. We show that, in contrast, learning speeds up with increasing population size if feedback about the populationresponse modulates synaptic plasticity in addition to global reinforcement. The two feedback signals (reinforcement and population-response signal) can be encoded by ambient neurotransmitter concentrations which vary slowly, yielding a fully online plasticity rule where the learning of a... |
| Tipo: Manuscript |
Palavras-chave: Neuroscience. |
| Ano: 2008 |
URL: http://precedings.nature.com/documents/1976/version/1 |
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| John Skoyles. |
| A four year old child devotes half their total energy expenditure (TEE) to their brains. Even by 10 years-of-age it is still 30% (compared to an adult’s ≈12%). This extreme energy use results from a high brain/body size ratio – combined with a doubling of cerebral gray matter energy utilization (due to synaptic exuberance during cognitive neuromaturation). 

With extreme energy expenditure goes extreme vulnerability to hypoglycemia: (1) children become hypoglycemic after 24-36 hours of fast (compared to 60-72 hours in adults), and (2) their brains suffer neurological impairment (shown in disrupted P300 potentials) at a lower decrease in plasma glucose: 3.6 - 4.2 mmol L-1 in children rather... |
| Tipo: Presentation |
Palavras-chave: Developmental Biology; Neuroscience; Evolutionary Biology. |
| Ano: 2012 |
URL: http://precedings.nature.com/documents/7097/version/1 |
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| Alois Schloegl; Andreas Ziehe; Klaus-Robert Müller. |
| Objective: The aim is to compare various fully automated methods for reducing ocular artifacts from EEG recordings.
Methods: Seven automated methods including regression, six component-based methods for reducing ocular artifacts have been applied to 36 data sets from two different labs. The influence of various noise sources is analyzed and the ratio between corrected and uncorrected EEG spectra, has been used to quantify the distortion. 
Results: The results show that not only regression but also component-based methods are vulnerable to over- or under-compensation and can cause significant distortion of EEG. Despite common belief, component-based methods did not demonstrate an advantage over the simple regression method.... |
| Tipo: Manuscript |
Palavras-chave: Neuroscience. |
| Ano: 2009 |
URL: http://precedings.nature.com/documents/3446/version/1 |
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| Michel Thiebaut de Schotten; Flavio Dell'Acqua; Stephanie Forkel; Andrew Simmons; Francesco Vergani; Declan G.M. Murphy; Marco Catani. |
| Looking for a friend in the crowd, avoiding a sudden danger or contemplating a work of art are some examples of actions based on the efficiency of our visuo-spatial attention system. The specialization of the right brain hemisphere for visuo-spatial attention is a characteristic of most humans, but its anatomical basis remains largely unknown. Our study is the first to report in humans the existence of a bilateral parieto-frontal network whose hemispheric lateralization predicts the degree of specialization of the right hemisphere for visuo-spatial attention. Our results also suggest that this specialization is associated with an unbalanced speed of visuo-spatial processing between the two hemispheres. This lateralization may be predictive of visuo-spatial... |
| Tipo: Manuscript |
Palavras-chave: Neuroscience. |
| Ano: 2011 |
URL: http://precedings.nature.com/documents/5549/version/1 |
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| Ashiq Hussain; Luis Saraiva; Sigrun Korsching. |
| Trace amine-associated receptors (TAARs) in mammals recently have been shown to function as olfactory receptors. We have delineated the taar gene family in jawless, cartilaginous and bony fish (zero, two, and more than hundred genes, respectively). We conclude that taar genes are evolutionary much younger than the related OR and ORA/V1R olfactory receptor families, which are present already in lamprey, a jawless vertebrate. The two cartilaginous fish genes appear to be ancestral for two taar classes, each with mammalian and bony fish (teleost) representatives. Unexpectedly, a whole new clade, class III, of taar genes originated even later, within the teleost lineage. Taar genes from all three classes are expressed in subsets of zebrafish olfactory receptor... |
| Tipo: Poster |
Palavras-chave: Neuroscience; Evolutionary Biology. |
| Ano: 2011 |
URL: http://precedings.nature.com/documents/6448/version/1 |
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| Elena Yablonski-Alter; Mervan Agovic; Eleonora Gashi; Theodore Lidsky; Eitan Freedman; Shailesh Banerjee. |
| Cocaine inhibits high-affinity neurotransmitter uptake at the presynaptic nerve terminals to increase synaptic levels of dopamine, norepinephrine and serotonin^1^. This increase of synaptic dopamine may cause neurotoxicity^2,3^. At least two different mechanisms have been proposed for the development of dopamine-related neurotoxicity: 1) dopamine produces a free radical that may induce cell toxicity^2,3^ and 2) dopamine reduces glutamate transport at its presynaptic sites to increase synaptic levels of this amino acid^4^ and augments glutamate transmission by activating dopamine D1 receptors in different areas of the brain^5-7^. Increase in glutamatergic transmission mediated by the activation on N-methyl dextro-aspartate (NMDA) receptors has been shown to... |
| Tipo: Manuscript |
Palavras-chave: Neuroscience; Pharmacology. |
| Ano: 2008 |
URL: http://precedings.nature.com/documents/2319/version/1 |
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| David Burr; John Ross. |
| Evidence exists for a non-verbal capacity to apprehend number, in humans^1^ (including infants^2,3^) and in other primates^4-6^. Here we show that perceived numerosity is susceptible to adaptation, along with primary visual properties of a scene like colour, contrast, size and speed. Apparent numerosity was decreased by adapting to large numbers of dots and increased by adapting to small numbers, the effect depended entirely on the numerosity of the adapter, not on contrast, size, orientation or pixel density, and occurred with very low adapter contrasts. We suggest that numerosity is also an independent primary visual property, not reducible to others like spatial frequency or density of texture^7^. |
| Tipo: Manuscript |
Palavras-chave: Neuroscience. |
| Ano: 2007 |
URL: http://precedings.nature.com/documents/1353/version/1 |
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| John Morley; Susan Farr; William Banks; Steven N. Johnson; Kelvin A. Yamada; Lin Xu. |
| Amyloid beta protein (A[beta]) is well recognized as having a significant role in the pathogenesis of Alzheimer's disease (AD). The reason for the presence of A[beta] and its physiological role in non-disease states is not clear. In these studies, low doses of A[beta] enhanced memory retention in two memory tasks and enhanced acetylcholine production in the hippocampus _in vivo_. We then tested whether endogenous A[beta] has a role in learning and memory in young, cognitively intact mice by blocking endogenous A[beta] in healthy 2-month-old CD-1 mice. Blocking A[beta] with antibody to A[beta] or DFFVG (which blocks A[beta] binding) or decreasing A[beta] expression with an antisense directed at the A[beta] precursor APP all resulted in impaired... |
| Tipo: Manuscript |
Palavras-chave: Neuroscience. |
| Ano: 2008 |
URL: http://precedings.nature.com/documents/2119/version/1 |
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| Registros recuperados: 585 | |
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