Search results for " format"
showing 10 items of 2156 documents
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…
Regulation of Dendritic Spine Morphology in Hippocampal Neurons by Copine-6.
2015
Dendritic spines compartmentalize information in the brain, and their morphological characteristics are thought to underly synaptic plasticity. Here we identify copine-6 as a novel modulator of dendritic spine morphology. We found that brain-derived neurotrophic factor (BDNF) - a molecule essential for long-term potentiation of synaptic strength - upregulated and recruited copine-6 to dendritic spines in hippocampal neurons. Overexpression of copine-6 increased mushroom spine number and decreased filopodia number, while copine-6 knockdown had the opposite effect and dramatically increased the number of filopodia, which lacked PSD95. Functionally, manipulation of post-synaptic copine-6 level…
NMDA Receptors Regulate the Structural Plasticity of Spines and Axonal Boutons in Hippocampal Interneurons
2017
N-methyl-D-aspartate receptors (NMDARs) are present in both pyramidal neurons and interneurons of the hippocampus. These receptors play an important role in the adult structural plasticity of excitatory neurons, but their impact on the remodeling of interneurons is unknown. Among hippocampal interneurons, somatostatin-expressing cells located in the stratum oriens are of special interest because of their functional importance and structural characteristics: they display dendritic spines, which change density in response to different stimuli. In order to understand the role of NMDARs on the structural plasticity of these interneurons, we have injected acutely MK-801, an NMDAR antagonist, to …
Angiogenic response in an in vitro model of dog microvascular endothelial cells stimulated with antigenic extracts from Dirofilaria immitis adult wor…
2019
Abstract Background Angiogenesis can occur under pathological conditions when stimuli such as inflammation, vascular obstruction or hypoxia exist. These stimuli are present in cardiopulmonary dirofilariosis (Dirofilaria immitis). The aim of this study was to analyze the capacity of D. immitis antigens to modify the expression of angiogenic factors and trigger the formation of pseudocapillaries (tube-like structures) in an in vitro model of endothelial cells. Methods The expression of VEGF-A, sFlt, mEndoglin and sEndoglin in cultures of canine microvascular endothelial cells stimulated with extract of adult worms of D. immitis obtained from an untreated dog (DiSA) and from a dog treated for …
Effects of the LPA1 Receptor Deficiency and Stress on the Hippocampal LPA Species in Mice
2019
Lysophosphatidic acid (LPA) is an important bioactive lipid species that functions in intracellular signaling through six characterized G protein-coupled receptors (LPA1-6). Among these receptors, LPA1 is a strong candidate to mediate the central effects of LPA on emotion and may be involved in promoting normal emotional behaviors. Alterations in this receptor may induce vulnerability to stress and predispose an individual to a psychopathological disease. In fact, mice lacking the LPA1 receptor exhibit emotional dysregulation and cognitive alterations in hippocampus-dependent tasks. Moreover, the loss of this receptor results in a phenotype of low resilience with dysfunctional coping in res…
Chip Formation and Control
2008
This chapter provides comprehensive engineering knowledge and modelling techniques applied in description of chip formation in the cutting zone and its separation from the bulk material, flow, and final breaking. Possible classification systems, including different chip shapes and physical mechanisms of their formation, are specified. The mechanisms of brittle fracture-based and shear-type chips are characterized in terms of plastic deformation and fracture mechanics. The models of the shear angle using different mechanical approaches are discussed. In addition, representative examples of FEM simulations of different types of chips for turning and milling operations are presented. Formulas …
Characterization of multiciliated ependymal cells that emerge in the neurogenic niche of the aged zebrafish brain
2016
In mammals, ventricular walls of the developing brain maintain a neurogenic niche, in which radial glial cells act as neural stem cells (NSCs) and generate new neurons in the embryo. In the adult brain, the neurogenic niche is maintained in the ventricular-subventricular zone (V-SVZ) of the lateral wall of lateral ventricles and the hippocampal dentate gyrus. In the neonatal V-SVZ, radial glial cells transform into astrocytic postnatal NSCs and multiciliated ependymal cells. On the other hand, in zebrafish, radial glial cells continue to cover the surface of the adult telencephalic ventricle and maintain a higher neurogenic potential in the adult brain. However, the cell composition of the …
FASTdoop: A versatile and efficient library for the input of FASTA and FASTQ files for MapReduce Hadoop bioinformatics applications
2017
Abstract Summary MapReduce Hadoop bioinformatics applications require the availability of special-purpose routines to manage the input of sequence files. Unfortunately, the Hadoop framework does not provide any built-in support for the most popular sequence file formats like FASTA or BAM. Moreover, the development of these routines is not easy, both because of the diversity of these formats and the need for managing efficiently sequence datasets that may count up to billions of characters. We present FASTdoop, a generic Hadoop library for the management of FASTA and FASTQ files. We show that, with respect to analogous input management routines that have appeared in the Literature, it offers…
Fast Regulation of GABAAR Diffusion Dynamics by Nogo-A Signaling.
2019
Summary: Precisely controlling the excitatory and inhibitory balance is crucial for the stability and information-processing ability of neuronal networks. However, the molecular mechanisms maintaining this balance during ongoing sensory experiences are largely unclear. We show that Nogo-A signaling reciprocally regulates excitatory and inhibitory transmission. Loss of function for Nogo-A signaling through S1PR2 rapidly increases GABAAR diffusion, thereby decreasing their number at synaptic sites and the amplitude of GABAergic mIPSCs at CA3 hippocampal neurons. This increase in GABAAR diffusion rate is correlated with an increase in Ca2+ influx and requires the calcineurin-mediated dephospho…
MicroRNA-22 Controls Aberrant Neurogenesis and Changes in Neuronal Morphology After Status Epilepticus
2018
Prolonged seizures (status epilepticus, SE) may drive hippocampal dysfunction and epileptogenesis, at least partly, through an elevation in neurogenesis, dysregulation of migration and aberrant dendritic arborization of newly-formed neurons. MicroRNA-22 was recently found to protect against the development of epileptic foci, but the mechanisms remain incompletely understood. Here, we investigated the contribution of microRNA-22 to SE-induced aberrant adult neurogenesis. SE was induced by intraamygdala microinjection of kainic acid (KA) to model unilateral hippocampal neuropathology in mice. MicroRNA-22 expression was suppressed using specific oligonucleotide inhibitors (antagomir-22) and ne…