861 research outputs found

    Impaired processing of facial happiness, with or without awareness, in developmental prosopagnosia

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    Developmental prosopagnosia (DP) is associated with severe, lifelong deficits in face recognition, with such cases often cited as support for a dissociation between the processing of facial identity and emotion. Here we examine the evidence against this dissociation and propose that the processing of facial happiness, either with or without awareness, is actually integrated within the same neural network involved in facial identity recognition. We also test this hypothesis on a group of DP cases and neurotypical controls (NT) by adapting them to expressionless neutral faces, intact happy faces and hybrid faces. Despite these hybrid faces being explicitly identified as expressionless due to their higher spatial frequencies taken from a neutral face, their low spatial frequencies convey happy facial expressions that participants are unaware of. After adaptation, participants were asked to judge the facial expressions of face stimuli that were morphed incrementally in varying degrees of sad through to happy. Both groups exhibited emotion adaptation aftereffects to the intact happy faces, although this effect was smaller in DP. Whereas NT produced emotion adaptation aftereffects without awareness of the happy emotion in the hybrid faces; as a group, those with DP did not. Furthermore, our DP cases also exhibited deficits in judging the emotion of the happiest morphed test faces. Our results indicate that the processing of happy facial expressions, with or without awareness, is likely integrated within the face recognition network. We hypothesise that the previously identified abnormalities in the fusiform gyrus in those with DP is the most likely structure responsible for these deficits.MOE (Min. of Education, S’pore)Accepted versio

    Brain-Derived Neurotrophic Factor Ameliorates Brain Stem Cardiovascular Dysregulation during Experimental Temporal Lobe Status Epilepticus

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    Background: Status epilepticus (SE) is an acute, prolonged epileptic crisis with a mortality rate of 20–30%; the underlying mechanism is not completely understood. We assessed the hypothesis that brain stem cardiovascular dysregulation occurs during SE because of oxidative stress in rostral ventrolateral medulla (RVLM), a key nucleus of the baroreflex loop; to be ameliorated by brain-derived neurotrophic factor (BDNF) via an antioxidant action. Methodology/Principal Findings: In a clinically relevant experimental model of temporal lobe SE (TLSE) using Sprague-Dawley rats, sustained hippocampal seizure activity was accompanied by progressive hypotension that was preceded by a reduction in baroreflex-mediated sympathetic vasomotor tone; heart rate and baroreflex-mediated cardiac responses remained unaltered. Biochemical experiments further showed concurrent augmentation of superoxide anion, phosphorylated p47 phox subunit of NADPH oxidase and mRNA or protein levels of BDNF, tropomyosin receptor kinase B (TrkB), angiotensin AT1 receptor subtype (AT1R), nitric oxide synthase II (NOS II) or peroxynitrite in RVLM. Whereas pretreatment by microinjection bilaterally into RVLM of a superoxide dismutase mimetic (tempol), a specific antagonist of NADPH oxidase (apocynin) or an AT1R antagonist (losartan) blunted significantly the augmented superoxide anion or phosphorylated p47 phox subunit in RVLM, hypotension and the reduced baroreflex-mediated sympathetic vasomotor tone during experimental TLSE, pretreatment with a recombinant human TrkB-Fc fusion protein or an antisense bdn

    Gender-Associated Cardiometabolic Risk Profiles and Health Behaviors in Patients With Type 2 Diabetes: A Cross-Sectional Analysis of the Joint Asia Diabetes Evaluation (JADE) Program

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    Background In Asia, diabetes-associated death due to cardiorenal diseases were 2–3 times higher in women than men which might be due to gender disparity in quality of care and health habits. Methods Adults with type 2 diabetes (T2D) from 11 Asian countries/areas were assessed using the same protocol (2007–2015). We compared treatment target attainment (HbA1c \u3c 7%, blood pressure [BP] \u3c 130/80 mmHg, risk-based LDL-cholesterol, lack of central obesity [waist circumference \u3c90 cm in men or \u3c80 cm in women), use of cardiorenal-protective drugs (renin-angiotensin system [RAS] inhibitors, statins), and self-reported health habits including self-monitoring blood glucose (SMBG) by gender. Analyses were stratified by countries/areas, age of natural menopause (\u3c50 vs. ≥50 years), and comorbidities (atherosclerotic cardiovascular disease [ASCVD], heart failure, kidney impairment [eGFR \u3c 60 mL/min/1.73 m2]). Findings Among 106,376 patients (53.2% men; median (interquartile range) diabetes duration: 6.0 (2.0–12.0) years; mean ± SD HbA1c 8.0 ± 1.9%; 27% insulin-treated), women were older and less likely to receive college education than men (28.9% vs. 48.8%). Women were less likely to smoke/drink alcohol and were physically less active than men. Women had lower BP (\u3c130/80 mmHg: 29.4% vs. 25.7%), less general obesity (54.8% vs. 57.8%) but more central obesity than men (77.5% vs. 57.3%). Women were less likely to have ASCVD (12.8% vs. 17.0%) or heart failure (1.3% vs. 2.3%), but more likely to have kidney impairment (22.3% vs. 17.6%) and any-site cancer than men (2.5% vs. 1.6%). In most countries/areas, more men attained HbA1c \u3c7% and risk-based LDL-cholesterol level than women. After adjusting for potential confounders including countries and centres, men had 1.63 odds ratio (95% CI 1.51, 1.74) of attaining ≥3 treatment targets than women. Interpretation Asian women with T2D had worse quality of care than men especially in middle-income countries/areas, calling for targeted implementation programs to close these care gaps

    Imaging Trans-Cellular Neurexin-Neuroligin Interactions by Enzymatic Probe Ligation

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    Neurexin and neuroligin are transmembrane adhesion proteins that play an important role in organizing the neuronal synaptic cleft. Our lab previously reported a method for imaging the trans-synaptic binding of neurexin and neuroligin called BLINC (Biotin Labeling of INtercellular Contacts). In BLINC, biotin ligase (BirA) is fused to one protein while its 15-amino acid acceptor peptide substrate (AP) is fused to the binding partner. When the two fusion proteins interact across cellular junctions, BirA catalyzes the site-specific biotinylation of AP, which can be read out by staining with streptavidin-fluorophore conjugates. Here, we report that BLINC in neurons cannot be reproduced using the reporter constructs and labeling protocol previously described. We uncover the technical reasons for the lack of reproducibilty and then re-design the BLINC reporters and labeling protocol to achieve neurexin-neuroligin BLINC imaging in neuron cultures. In addition, we introduce a new method, based on lipoic acid ligase instead of biotin ligase, to image trans-cellular neurexin-neuroligin interactions in human embryonic kidney cells and in neuron cultures. This method, called ID-PRIME for Interaction-Dependent PRobe Incorporation Mediated by Enzymes, is more robust than BLINC due to higher surface expression of lipoic acid ligase fusion constructs, gives stronger and more localized labeling, and is more versatile than BLINC in terms of signal readout. ID-PRIME expands the toolkit of methods available to study trans-cellular protein-protein interactions in living systems.National Institutes of Health (U.S.) (DP1 OD003961

    Understanding Dwarf Galaxies in order to Understand Dark Matter

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    Much progress has been made in recent years by the galaxy simulation community in making realistic galaxies, mostly by more accurately capturing the effects of baryons on the structural evolution of dark matter halos at high resolutions. This progress has altered theoretical expectations for galaxy evolution within a Cold Dark Matter (CDM) model, reconciling many earlier discrepancies between theory and observations. Despite this reconciliation, CDM may not be an accurate model for our Universe. Much more work must be done to understand the predictions for galaxy formation within alternative dark matter models.Comment: Refereed contribution to the Proceedings of the Simons Symposium on Illuminating Dark Matter, to be published by Springe

    Measurement of χ c1 and χ c2 production with s√ = 7 TeV pp collisions at ATLAS

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    The prompt and non-prompt production cross-sections for the χ c1 and χ c2 charmonium states are measured in pp collisions at s√ = 7 TeV with the ATLAS detector at the LHC using 4.5 fb−1 of integrated luminosity. The χ c states are reconstructed through the radiative decay χ c → J/ψγ (with J/ψ → μ + μ −) where photons are reconstructed from γ → e + e − conversions. The production rate of the χ c2 state relative to the χ c1 state is measured for prompt and non-prompt χ c as a function of J/ψ transverse momentum. The prompt χ c cross-sections are combined with existing measurements of prompt J/ψ production to derive the fraction of prompt J/ψ produced in feed-down from χ c decays. The fractions of χ c1 and χ c2 produced in b-hadron decays are also measured
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