Search results for "EB"
showing 10 items of 15658 documents
Topographic Independent Component Analysis reveals random scrambling of orientation in visual space
2017
Neurons at primary visual cortex (V1) in humans and other species are edge filters organized in orientation maps. In these maps, neurons with similar orientation preference are clustered together in iso-orientation domains. These maps have two fundamental properties: (1) retinotopy, i.e. correspondence between displacements at the image space and displacements at the cortical surface, and (2) a trade-off between good coverage of the visual field with all orientations and continuity of iso-orientation domains in the cortical space. There is an active debate on the origin of these locally continuous maps. While most of the existing descriptions take purely geometric/mechanistic approaches whi…
Analysis of Microstructure of the Cardiac Conduction System Based on Three-Dimensional Confocal Microscopy
2016
The specialised conducting tissues present in the ventricles are responsible for the fast distribution of the electrical impulse from the atrio-ventricular node to regions in the subendocardial myocardium. Characterisation of anatomical features of the specialised conducting tissues in the ventricles is highly challenging, in particular its most distal section, which is connected to the working myocardium via Purkinje-myocardial junctions. The goal of this work is to characterise the architecture of the distal section of the Purkinje network by differentiating Purkinje cells from surrounding tissue, performing a segmentation of Purkinje fibres at cellular scale, and mathematically describin…
Vascular pathology: Cause or effect in Alzheimer disease?
2018
Introduction: Alzheimer disease (AD) is the main cortical neurodegenerative disease. The incidence of this disease increases with age, causing significant medical, social and economic problems, especially in countries with ageing populations. Objective: This review aims to highlight existing evidence of how vascular dysfunction may contribute to cognitive impairment in AD, as well as the therapeutic possibilities that might arise from this evidence. Development: The vascular hypothesis emerged as an alternative to the amyloid cascade hypothesis as an explanation for the pathophysiology of AD. This hypothesis locates blood vessels as the origin for a variety of pathogenic pathways that lead …
Biofilm biodiversity in French and Swiss show caves using the metabarcoding approach: First data.
2018
International audience; In recent decades, show caves have begun to suffer from microorganism proliferation due to artificial lighting installations for touristic activity. In addition to the aesthetic problem, light encourages microorganisms that are responsible for physical and chemical degradation of limestone walls, speleothems and prehistoric paintings of cultural value. Microorganisms have previously been described by microscopy or culture-dependent methods, but data provided by new generation sequencing are rare. The authors identified, for the first time, microorganisms proliferating in one Swiss and in four French show caves using three different primers. The results showed that bo…
GW-Bodies and P-Bodies Constitute Two Separate Pools of Sequestered Non-Translating RNAs
2015
Non-translating RNAs that have undergone active translational repression are culled from the cytoplasm into P-bodies for decapping-dependent decay or for sequestration. Organisms that use microRNA-mediated RNA silencing have an additional pathway to remove RNAs from active translation. Consequently, proteins that govern microRNA-mediated silencing, such as GW182/Gw and AGO1, are often associated with the P-bodies of higher eukaryotic organisms. Due to the presence of Gw, these structures have been referred to as GW-bodies. However, several reports have indicated that GW-bodies have different dynamics to P-bodies. Here, we use live imaging to examine GW-body and P-body dynamics in the early …
Composition and geographic variation of the bacterial microbiota associated with the coelomic fluid of the sea urchin Paracentrotus lividus
2020
AbstractIn the present work, culture-based and culture-independent investigations were performed to determine the microbiota structure of the coelomic fluid of Mediterranean sea urchin Paracentrotus lividus individuals collected from two distinct geographical sites neighboring a high-density population bay and a nature reserve, respectively. Next Generation Sequencing analysis of 16S rRNA gene (rDNA) showed that members of the Proteobacteria, Bacteroidetes and Fusobacteria phyla, which have been previously reported to be commonly retrieved from marine invertebrates, dominate the overall population of microorganisms colonizing this liquid tissue, with minority bacterial genera exhibiting rem…
Reactome graph database: Efficient access to complex pathway data
2018
Reactome is a free, open-source, open-data, curated and peer-reviewed knowledgebase of biomolecular pathways. One of its main priorities is to provide easy and efficient access to its high quality curated data. At present, biological pathway databases typically store their contents in relational databases. This limits access efficiency because there are performance issues associated with queries traversing highly interconnected data. The same data in a graph database can be queried more efficiently. Here we present the rationale behind the adoption of a graph database (Neo4j) as well as the new ContentService (REST API) that provides access to these data. The Neo4j graph database and its qu…
Modeling of Myotonic Dystrophy Cardiac Phenotypes in Drosophila
2018
After respiratory distress, cardiac dysfunction is the second most common cause of fatality associated with the myotonic dystrophy (DM) disease. Despite the prevalance of heart failure in DM, physiopathological studies on heart symptoms have been relatively scarce because few murine models faithfully reproduce the cardiac disease. Consequently, only a small number of candidate compounds have been evaluated in this specific phenotype. To help cover this gap Drosophila combines the amenability of its invertebrate genetics with the possibility of quickly acquiring physiological parameters suitable for meaningful comparisons with vertebrate animal models and humans. Here we review available des…
Alterations in Tau Protein Level and Phosphorylation State in the Brain of the Autistic-Like Rats Induced by Prenatal Exposure to Valproic Acid
2021
Autism spectrum disorder (ASD) is a neurodevelopmental condition characterized by deficient social interaction and communication besides repetitive, stereotyped behaviours. A characteristic feature of ASD is altered dendritic spine density and morphology associated with synaptic plasticity disturbances. Since microtubules (MTs) regulate dendritic spine morphology and play an important role in spine development and plasticity the aim of the present study was to investigate the alterations in the content of neuronal α/β-tubulin and Tau protein level as well as phosphorylation state in the valproic acid (VPA)-induced rat model of autism. Our results indicated that maternal exposure to VPA indu…
Neuronal LRP4 regulates synapse formation in the developing CNS
2017
The low-density lipoprotein receptor-related protein 4 (LRP4) is essential in muscle fibers for the establishment of the neuromuscular junction. Here, we show that LRP4 is also expressed by embryonic cortical and hippocampal neurons, and that downregulation of LRP4 in these neurons causes a reduction in density of synapses and number of primary dendrites. Accordingly, overexpression of LRP4 in cultured neurons had the opposite effect inducing more but shorter primary dendrites with an increased number of spines. Transsynaptic tracing mediated by rabies virus revealed a reduced number of neurons presynaptic to the cortical neurons in which LRP4 was knocked down. Moreover, neuron-specific kno…