Publications by authors named "Gebara E"

Unlabelled: Social behaviors such as cooperation are crucial for mammals. A deeper knowledge of the neuronal mechanisms underlying cooperation can be beneficial for people suffering from pathologies with impaired social behavior. Our aim was to study the brain activity when two animals synchronize their behavior to obtain a mutual reinforcement.

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The TAR DNA Binding Protein 43 (TDP-43) has been implicated in the pathogenesis of human neurodegenerative diseases and exhibits hallmark neuropathology in amyotrophic lateral sclerosis (ALS). Here, we explore its tractability as a plasma biomarker of disease and describe its localization and possible functions in the cytosol of platelets. Novel TDP-43 immunoassays were developed on three different technical platforms and qualified for specificity, signal-to-noise ratio, detection range, variation, spike recovery and dilution linearity in human plasma samples.

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Retrotransposons comprise about 45% of the human genome, but their contributions to human trait variation and evolution are only beginning to be explored. Here, we find that a sequence of SVA retrotransposon insertions in an early intron of the ASIP (agouti signaling protein) gene has probably shaped human pigmentation several times. In the UK Biobank (n = 169,641), a recent 3.

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The nucleus accumbens (NAc) is a brain hub regulating motivated behaviors, including social competitiveness. Mitochondrial function in the NAc links anxiety with social competitiveness, and the mitochondrial fusion protein mitofusin 2 (Mfn2) in NAc neurons regulates anxiety-related behaviors. However, it remains unexplored whether accumbal Mfn2 levels also affect social behavior and whether Mfn2 actions in the emotional and social domain are driven by distinct cell types.

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Low-dose human interleukin-2 (hIL-2) treatment is used clinically to treat autoimmune disorders due to the cytokine's preferential expansion of immunosuppressive regulatory T cells (Tregs). However, off-target immune cell activation and short serum half-life limit the clinical potential of IL-2 treatment. Recent work showed that complexes comprising hIL-2 and the anti-hIL-2 antibody F5111 overcome these limitations by preferentially stimulating Tregs over immune effector cells.

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Background: Emerging evidence points to a central role of mitochondria in psychiatric disorders. However, little is known about the molecular players that regulate mitochondria in neural circuits regulating anxiety and depression and about how they impact neuronal structure and function. Here, we investigated the role of molecules involved in mitochondrial dynamics in medium spiny neurons (MSNs) from the nucleus accumbens (NAc), a hub of the brain's motivation system.

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A decrease in adult hippocampal neurogenesis has been linked to age-related cognitive impairment. However, the mechanisms involved in this age-related reduction remain elusive. Glucocorticoid hormones (GC) are important regulators of neural stem/precursor cells (NSPC) proliferation.

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Aggression is frequently observed in neurodevelopmental psychiatric disorders such as schizophrenia, autism, and bipolar disorder. Due to a lack of understanding of its underlying mechanisms, effective treatments for abnormal aggression are still missing. Recently, genetic variations in Sialyltransferase 2 (St8sia2) have been linked to these disorders and aggression.

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Mossy cells (MCs) represent a major population of excitatory neurons in the adult dentate gyrus, a brain region where new neurons are generated from radial neural stem cells (rNSCs) throughout life. Little is known about the role of MCs in regulating rNSCs. Here we demonstrate that MC commissural projections structurally and functionally interact with rNSCs through both the direct glutamatergic MC-rNSC pathway and the indirect GABAergic MC-local interneuron-rNSC pathway.

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Postnatal hippocampal neurogenesis induces network remodeling and may participate to mechanisms of learning. In turn, the maturation and survival of newborn neurons is regulated by their activity. Here, we tested the effect of a cell-autonomous overexpression of synaptic adhesion molecules on the maturation and survival of neurons born postnatally and on hippocampal-dependent memory performances.

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Adult hippocampal neurogenesis relies on the activation of neural stem cells in the dentate gyrus, their division, and differentiation of their progeny into mature granule neurons. The complex morphology of radial glia-like (RGL) stem cells suggests that these cells establish numerous contacts with the cellular components of the neurogenic niche that may play a crucial role in the regulation of RGL stem cell activity. However, the morphology of RGL stem cells remains poorly described.

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Adult neurogenesis is tightly regulated by the neurogenic niche. Cellular contacts between niche cells and neural stem cells are hypothesized to regulate stem cell proliferation or lineage choice. However, the structure of adult neural stem cells and the contact they form with niche cells are poorly described.

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Adult neurogenesis is regulated by the neurogenic niche, through mechanisms that remain poorly defined. Here, we investigated whether niche-constituting astrocytes influence the maturation of adult-born hippocampal neurons using two independent transgenic approaches to block vesicular release from astrocytes. In these models, adult-born neurons but not mature neurons showed reduced glutamatergic synaptic input and dendritic spine density that was accompanied with lower functional integration and cell survival.

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Aging is associated with increased inflammation and reduced hippocampal neurogenesis, which may in turn contribute to cognitive impairment. Taurine is a free amino acid found in numerous diets, with anti-inflammatory properties. Although abundant in the young brain, the decrease in taurine concentration with age may underlie reduced neurogenesis.

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Adult hippocampal neurogenesis results in the continuous formation of new neurons and is a process of brain plasticity involved in learning and memory. The neurogenic niche regulates the stem cell proliferation and the differentiation and survival of new neurons and a major contributor to the neurogenic niche are astrocytes. Among the molecules secreted by astrocytes, D-serine is an important gliotransmitter and is a co-agonist of the glutamate, N-methyl-D-aspartate (NMDA) receptor.

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Adult hippocampal neurogenesis results in the formation of new neurons and is a process of brain plasticity involved in learning and memory. The proliferation of adult neural stem or progenitor cells is regulated by several extrinsic factors such as experience, disease or aging and intrinsic factors originating from the neurogenic niche. Microglia is very abundant in the dentate gyrus (DG) and increasing evidence indicates that these cells mediate the inflammation-induced reduction in neurogenesis.

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Adult hippocampal neurogenesis results in the continuous formation of new neurons and is a process of brain plasticity involved in learning and memory. Although inducible-reversible transgenic mouse models are increasingly being used to investigate adult neurogenesis, transgene control requires the administration of an activator, doxycycline (Dox), with unknown effects on adult neurogenesis. Here, we tested the effect of Dox administration on adult neurogenesis in vivo.

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Stimulation of resident cells by NF-κB activating cytokines is a central element of inflammatory and degenerative disorders of the central nervous system (CNS). This disease-mediated NF-κB activation could be used to drive transgene expression selectively in affected cells, using adeno-associated virus (AAV)-mediated gene transfer. We have constructed a series of AAV vectors expressing GFP under the control of different promoters including NF-κB -responsive elements.

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Prostaglandin E1 (PGE1) infusion is usually administered for short periods to maintain patency of ductus arteriosus in infants with cyanotic heart disease. Prolonged therapy may be necessary while patients are awaiting surgical treatment. Several side effects occur at the onset of the treatment, most of them reversible once the treatment is discontinued.

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Congenital adrenal hyperplasia is a group of disorders resulting from the deficiency of one of the five enzymes required for the synthesis of cortisol. The most frequent is the steroid 21-hydroxylase deficiency, accounting for more than 90% of the cases. The capacity of aldosterone synthesis is also decreased in 75% of the affected infants, resulting in salt-wasting type and life-threatening metabolic crisis.

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Neonatal hemochromatosis is a rare clinical pathologic entity, defined by severe neonatal liver failure of intrauterine onset associated with intra-and extra- hepatic siderosis that spares reticuloendothelial system. It is the most frequently recognized cause of liver failure in neonates. The cause is unknown but it may develop secondary to abnormal fetoplacental iron handling or perinatal liver disease or be familial or as a consequence of gestational alloimmune disease.

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Aim: The present study aimed to evaluate if the oral cavity of chronic periodontitis patients can harbor Helicobacter pylori after systemic eradication therapy.

Materials And Methods: Samples of 30 patients (15 with gingivitis and 15 with chronic periodontitis) positive for H. pylori in the stomach were evaluated.

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Helicobacter pylori is an important gastrointestinal pathogen associated with gastritis, peptic ulcers, and an increased risk of gastric carcinoma. The oral cavity has been indicated as a possible H. pylori reservoir, and may therefore be involved in the reinfection of the stomach which sometimes follows treatment of H.

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