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| Registros recuperados: 585 | |
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| Antti Niemi; Andrey Krokhotin. |
| Alzheimer's disease has a devastating impact on its victims by causing severe neurodegeneration in the brain that leads to a certain death. Only in a small number of cases can the origin be traced to a variety of genetic mutations, for the greater part the reasons for its onset are unclear.The defining factor is the formation of extracellular senile amyloid plaques in the brain, but therapeutic approaches to remove them remain to be shown effective in humans. Here we investigate physical processes that are involved in the release of the extracellular amyloid, by scrutinizing the intracellular domain of its precursor protein. We identify a phenomenon that has never before been discussed in the context of protein research: Like ice and water... |
| Tipo: Manuscript |
Palavras-chave: Molecular Cell Biology; Neuroscience; Bioinformatics. |
| Ano: 2011 |
URL: http://precedings.nature.com/documents/6030/version/1 |
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| Bradly J. Alicea. |
| Stochastic resonance (SR) is a concept from the physics and engineering communities that has applicability to both systems physiology and other living systems. In this paper, it will be argued that stochastic resonance plays a role in driving behavior in neuromechanical systems. The theory of stochastic resonance will be discussed, followed by a series of expected outcomes, and two tests of stochastic resonance in an experimental setting. These tests are exploratory in nature, and provide a means to parameterize systems that couple biological and mechanical components. Finally, the potential role of stochastic resonance in adaptive physiological systems will be discussed. |
| Tipo: Manuscript |
Palavras-chave: Neuroscience. |
| Ano: 2009 |
URL: http://precedings.nature.com/documents/3301/version/1 |
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| Allen Institute for Brain Science; Josh J. Burnell; Lydia L. Ng; Angela L. Guillozet-Bongaarts. |
| This report contains a gene expression summary of the oculomotor nucleus, derived from the Allen Brain Atlas (ABA) in situ hybridization mouse data set. The structure's location and morphological characteristics in the mouse brain are described using the Nissl data found in the Allen Reference Atlas. Using an established algorithm, the expression values of the oculomotor nucleus were compared to the values of the macro/parent-structure, in this case the midbrain, for the purpose of extracting regionally selective gene expression data. The genes with the highest ranking selectivity ratios were manually curated and verified. 50 genes were then selected and compiled for expression characterization. The experimental data for each gene may be accessed... |
| Tipo: Manuscript |
Palavras-chave: Genetics & Genomics; Neuroscience. |
| Ano: 2008 |
URL: http://precedings.nature.com/documents/2094/version/1 |
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| Roberto C Sotero; Yasser Iturria-Medina. |
| A theoretical framework is presented for converting Blood Oxygenation Level Dependent (BOLD) images to temperature maps, based on the idea that disproportional local changes in cerebral blood flow (CBF) as compared with cerebral metabolic rate of oxygen consumption (CMRO2) during functional brain activity, lead to both brain temperature changes and the BOLD effect. Using an oxygen limitation model and a BOLD signal model we obtain a transcendental equation relating CBF and CMRO2 changes with the corresponding BOLD signal, which is solved in terms of the Lambert W function. Inserting this result in the dynamic bio-heat equation describing the rate of temperature changes in the brain, we obtain a non autonomous ordinary differential equation that depends on... |
| Tipo: Manuscript |
Palavras-chave: Neuroscience. |
| Ano: 2010 |
URL: http://precedings.nature.com/documents/4772/version/1 |
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| Timm Lochmann; Tim Blanche; Daniel A. Butts. |
| Despite detailed knowledge about the anatomy and physiology of the primary visual cortex (V1), the immense number of feed-forward and recurrent connections onto a given V1 neuron make it difficult to understand how the physiological details relate to a given neuron’s functional properties. Here, we focus on a well-known functional property of many V1 complex cells: phase-invariant direction selectivity (DS). While the energy model explains its construction at the conceptual level, it remains unclear how the mathematical operations described in this model are implemented by cortical circuits. To understand how DS of complex cells is constructed in cortex, we apply a nonlinear modeling framework to extracellular data from macaque V1. We use a... |
| Tipo: Poster |
Palavras-chave: Neuroscience. |
| Ano: 2011 |
URL: http://precedings.nature.com/documents/5861/version/1 |
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| Rodrick Wallace. |
| Protein folding disorders of aging like Alzheimer's and Parkinson's diseases currently present intractable medical challenges. 'Small molecule' interventions - drug treatments - often have, at best, palliative impact, failing to alter disease course. The design of individual or population level interventions will likely require a deeper understanding of protein folding and its regulation than currently provided by contemporary 'physics' or culture-bound medical magic bullet models. Here, a topological rate distortion analysis is applied to the problem of protein folding and regulation that is similar in spirit to Tlusty's (2010a) elegant exploration of the genetic code. The formalism produces... |
| Tipo: Manuscript |
Palavras-chave: Biotechnology; Developmental Biology; Molecular Cell Biology; Neuroscience; Pharmacology. |
| Ano: 2010 |
URL: http://precedings.nature.com/documents/4847/version/1 |
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| William D. Klipec; Steven Faux. |
| We have developed a methodology for recording a robust P300 event related potential (ERP) in rats. In these experiments a contingency shaped model of the human “oddball’ paradigm was employed in which rats were shaped to press a lever for food reinforcement signaled by the click of the pellet dispenser. A target tone cued the insertion of the lever that retracted after 1­sec or immediately following a single reinforced response, while a non­target tone was randomly presented. Brain activity was recorded through stainless steel electrodes implanted 1mm below the skull. Here, we compared the amplitude of the P300 response to the click of the pellet dispenser to the amplitude of the P300 response to the target and... |
| Tipo: Manuscript |
Palavras-chave: Neuroscience. |
| Ano: 2012 |
URL: http://precedings.nature.com/documents/7100/version/1 |
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| Bernd Kastenholz; Basil Horst; Jürgen Horst. |
| Commercially available medicinal plant extracts such as Ginkgo biloba leaf extract show no consistent pattern of clinical benefit for people with dementia or cognitive impairment, and have been suggested to be toxic to cells at higher doses. However, medicinal plants may contain other more efficient bioactive molecules apart from the well-known flavonoids and terpenoids. Therapeutic recombinant plant-made copper chaperone for superoxide dismutase (CCS) derived from Ginkgo biloba leaves may establish and maintain physiologic Cu levels through restoration and modulation of biometal metabolism in organ systems of younger Alzheimer patients (> 50 years). Medications developed from plant-made copper chaperone proteins may delay progression during early... |
| Tipo: Manuscript |
Palavras-chave: Neuroscience; Pharmacology. |
| Ano: 2011 |
URL: http://precedings.nature.com/documents/5907/version/3 |
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| Kentaro Onizuka. |
| The Entropic Landscape Analysis was applied to the prion protein sequences of various mammals in order to detect potential sites of variants that would be responsible for the susceptibility of prion disease infection. Among familiar mammals, canines including dogs have been demonstrating strong resistance to prion diseases. Among the canine specifc substitutions the entropic landscape analysis pinpoints the substitutions Asn104Gly and Ser107Asn having the biggest impact to the conformational transition and stability. Although they must be further corroborated by experiments in vivo et vitro, the results are demonstrating that the entropic landscape analysis is useful enough to screen substitutions and polymorphisms potentially relevant to conformational... |
| Tipo: Manuscript |
Palavras-chave: Genetics & Genomics; Neuroscience; Bioinformatics; Evolutionary Biology. |
| Ano: 2009 |
URL: http://precedings.nature.com/documents/3043/version/1 |
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| Emiliana Simon-Thomas; Disa Sauter; Lara Sinicropi-Yao; Anna Abramson; Dacher Keltner. |
| Studies of emotion signaling have proven critical to scientific advances in understanding emotion, informing claims about the evolutionary origins of different emotions1, the central and peripheral nervous system correlates of emotion 2 3 and even which states warrant consideration in emotion taxonomies 4. An initial wave of empirical studies of emotion-related facial expression5 and vocalization 6 7 has concentrated almost exclusively on a limited set of emotions - anger, disgust, fear, sadness, surprise, happiness, and tenderness. More recent work on emotional facial expressions has expanded this framework, documenting reliable displays of other emotions like embarrassment and shame 8, pride 9, and love and desire 10 . Here, we present two studies that... |
| Tipo: Manuscript |
Palavras-chave: Ecology; Neuroscience. |
| Ano: 2007 |
URL: http://precedings.nature.com/documents/1356/version/1 |
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| Aaron G. Filler. |
| Objective – Methods were invented that made it possible to image peripheral nerves in the body and to image neural tracts in the brain. Over a 15 year period, these techniques – MR Neurography and Diffusion Tensor Imaging – were then deployed in the clinical and research community and applied to about 50,000 patients. Within this group, about 5,000 patients having MR Neurography were carefully tracked on a prospective basis.

Method – In the study group a uniform imaging methodology was applied and all images were reviewed and registered by referral source, clinical indication, efficacy of imaging and quality. Various classes of image findings were identified and subjected to a... |
| Tipo: Manuscript |
Palavras-chave: Neuroscience. |
| Ano: 2009 |
URL: http://precedings.nature.com/documents/2877/version/1 |
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| Florian Raudies; Ennio Mingolla; Michael Hasselmo. |
| *Problem.* Various cues such as vestibular, sensorimotor, or visual information can lead to the firing of grid cells recorded in entorhinal cortex of rats. A recent model uses boundary vector cells to provide information about the 2D spatial position (Barry et al., Review Neuroscience, 17, 2006). However, boundary vector cells need to know the angle and distance of the boundary wall. In contrast we study the estimation of 2D velocity and change of heading of the rat from optic flow and if this information can lead to grid cell firing.
*Approach.* A simple circular cage is modeled as a 3D world and trajectories of a rat’s movement are simulated. Optic flow for a spherical camera model is calculated for regularly sampled locations... |
| Tipo: Manuscript |
Palavras-chave: Neuroscience. |
| Ano: 2011 |
URL: http://precedings.nature.com/documents/5839/version/1 |
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| Asuka Suzuki-Hirano; Tatsuya Sato; Harukazu Nakamura. |
| In the previous studies, we showed that strong Fgf8 signaling activates the Ras-ERK pathway to induce cerebellum. Here, we show importance of negative regulation of this pathway. 'Prolonged' activation of ERK by misexpression of _Fgf8b_ and dominant-negative _Sprouty2_ (_dnSprouty2_) did not change the fate of the mesencephalic alar plate. Downregulation of ERK activity using a MEK inhibitor, U0126, or by tetracycline dependent Tet-off system after co-expression of _Fgf8b_ and _dnSprouty2_, forced the mesencephalic alar plate to differentiate into cerebellum. We then paid attention to Mkp3. After misexpression of _dnMkp3_ and _Fgf8b_, slight downregulation of ERK activity occurred, which may be due to Sprouty2, and the mesencephalon... |
| Tipo: Manuscript |
Palavras-chave: Developmental Biology; Molecular Cell Biology; Neuroscience. |
| Ano: 2008 |
URL: http://precedings.nature.com/documents/2089/version/1 |
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| Thomas Frodl; Yolande Ferguson; Andrew Fagan; Danusia Lisiecka; Angela Carballedo; Ian Daly; James Meaney; Dermot Kelleher. |
| Mental disorders are a major cause of long-term disability and are a direct cause of mortality, with approximately 800.000 individuals dying from suicide every year worldwide - a high proportion of them related to major depressive disorder (MDD)^1^. Healthy relatives of patients with major depressive disorder (MDD) are at risk to develop the disease. This higher vulnerability is associated with structural^2-4^ and functional brain changes^5^. However, we found using high angular resolution diffusion imaging (HARDI) with 61 diffusion directions that neuron tracts between frontal cortices and limbic as well as temporal and parietal brain regions are characterized by better diffusion coefficients in unaffected relatives (UHR), who managed to stay healthy,... |
| Tipo: Manuscript |
Palavras-chave: Neuroscience. |
| Ano: 2010 |
URL: http://precedings.nature.com/documents/4793/version/2 |
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| Kenichi Shibuya; Masako Iwadate; Tomoko Sadamoto. |
| How is muscle force modulated during hand exercise? Oxygenation in the contralateral primary motor cortex (M1) has been observed to vary considerably across trials of repetitive handgrip exercise. No linear relationship was observed between the average value of oxygenation determined by a block design study and the force of the handgrip. We found reduced oxygenation in the ipsilateral M1 and unchanged oxygenation in the contralateral M1 during repetitive static handgrip exercises (40% and 60% maximal voluntary contraction; 10 s exercise/75 s rest; 5 sets), which might be due to short-term motor learning. These results support the hypothesis that the ipsilateral M1 might functionally compensate for the contralateral M1 in force modulation during unilateral... |
| Tipo: Manuscript |
Palavras-chave: Neuroscience. |
| Ano: 2008 |
URL: http://precedings.nature.com/documents/1865/version/1 |
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| Andras Gelencser; Themistoklis Prodromakis; Christofer Toumazou; Tamas Roska. |
| In this paper we present a biorealistic model for the first part of the early vision processing by incorporating memristive nanodevices. The architecture of the proposed network is based on the organisation and functioning of the outer plexiform layer (OPL) in the vertebrate retina. We demonstrate that memristive devices are indeed a valuable building block for neuromorphic architectures, as their highly non-linear and adaptive response could be exploited for establishing ultra-dense networks with similar dynamics to their biological counterparts. We particularly show that hexagonal memristive grids can be employed for faithfully emulating the smoothing-effect occurring at the OPL for enhancing the dynamic range of the system. In addition, we employ a... |
| Tipo: Manuscript |
Palavras-chave: Neuroscience; Bioinformatics. |
| Ano: 2011 |
URL: http://precedings.nature.com/documents/6664/version/1 |
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| Brandon J. Farley; Arnaud Norena. |
| Imaging neural activity across a large (several mm) cortical area with high temporal and spatial resolution is desirable, for example in the auditory system to measure cortical processing across a broad frequency spectrum. Voltage-sensitive dye imaging (VSDI) has a unique combination of properties making this possible, but so far studies have been limited to studying simple sparsely-presented sensory stimuli. We demonstrate the feasibility of long-acquisition VSDI (using the dye RH-1691) in auditory cortex while presenting complex time-varying acoustic stimuli or silence. Using a dense array of partially-overlapping 50 ms tone pips (8 frequencies per octave spanning six octaves), we obtained high-resolution spectrotemporal receptive fields (STRFs)... |
| Tipo: Manuscript |
Palavras-chave: Neuroscience. |
| Ano: 2011 |
URL: http://precedings.nature.com/documents/5820/version/1 |
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| Adrian G. Dyer; Alan Dorin; Verena Reinhardt; Marcello G. P. Rosa. |
| Foraging bees use colour cues to help identify rewarding from unrewarding flowers, but as conditions change, bees may require behavioural flexibility to reverse their learnt preferences. Perceptually similar colours are learnt slowly by honeybees and thus potentially pose a difficult task to reverse-learn. Free-flying honeybees (N = 32) were trained to learn a fine colour discrimination task that could be resolved at ca. 70% accuracy following extended differential conditioning, and were then tested for their ability to reverse-learn this visual problem multiple times. Subsequent analyses identified three different strategies: ‘Deliberative-decisive’ bees that could, after several flower visits, decisively make a large change to... |
| Tipo: Manuscript |
Palavras-chave: Ecology; Neuroscience. |
| Ano: 2012 |
URL: http://precedings.nature.com/documents/7037/version/1 |
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| Registros recuperados: 585 | |
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