20 research outputs found

    Taurine is a potent activator of extrasynaptic GABAA receptors in the thalamus

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    Taurine is one of the most abundant free amino acids in the brain. In a number of studies, taurine has been reported to activate glycine receptors (Gly-Rs) at moderate concentrations (>= 100 mu M), and to be a weak agonist at GABA(A) receptors (GABA(A)-Rs), which are usually activated at high concentrations (>= 1 mM). In this study, we show that taurine reduced the excitability of thalamocortical relay neurons and activated both extrasynaptic GABAA-Rs and Gly-Rs in neurons in the mouse ventrobasal (VB) thalamus. Low concentrations of taurine (10 - 100 mu M) decreased neuronal input resistance and firing frequency, and elicited a steady outward current under voltage clamp, but had no effects on fast inhibitory synaptic currents. Currents elicited by 50 mu M taurine were abolished by gabazine, insensitive to midazolam, and partially blocked by 20 mu M Zn2+, consistent with the pharmacological properties of extrasynaptic GABA(A)-Rs (alpha 4 beta 2 delta subtype) involved in tonic inhibition in the thalamus. Tonic inhibition was enhanced by an inhibitor of taurine transport, suggesting that taurine can act as an endogenous activator of these receptors. Taurine-evoked currents were absent in relay neurons from GABA(A)-R alpha 4 subunit knock-out mice. The amplitude of the taurine current was larger in neurons from adult mice than juvenile mice. Taurine was a more potent agonist at recombinant alpha(4)beta 2 delta GABA(A)-Rs than at alpha 1 beta 2 gamma 2 GABA(A)-Rs. We conclude that physiological concentrations of taurine can inhibit VB neurons via activation of extrasynaptic GABA(A)-Rs and that taurine may function as an endogenous regulator of excitability and network activity in the thalamus

    Internet of things

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    Manual of Digital Earth / Editors: Huadong Guo, Michael F. Goodchild, Alessandro Annoni .- Springer, 2020 .- ISBN: 978-981-32-9915-3Digital Earth was born with the aim of replicating the real world within the digital world. Many efforts have been made to observe and sense the Earth, both from space (remote sensing) and by using in situ sensors. Focusing on the latter, advances in Digital Earth have established vital bridges to exploit these sensors and their networks by taking location as a key element. The current era of connectivity envisions that everything is connected to everything. The concept of the Internet of Things(IoT)emergedasaholisticproposaltoenableanecosystemofvaried,heterogeneous networked objects and devices to speak to and interact with each other. To make the IoT ecosystem a reality, it is necessary to understand the electronic components, communication protocols, real-time analysis techniques, and the location of the objects and devices. The IoT ecosystem and the Digital Earth (DE) jointly form interrelated infrastructures for addressing today’s pressing issues and complex challenges. In this chapter, we explore the synergies and frictions in establishing an efficient and permanent collaboration between the two infrastructures, in order to adequately address multidisciplinary and increasingly complex real-world problems. Although there are still some pending issues, the identified synergies generate optimism for a true collaboration between the Internet of Things and the Digital Earth

    Convergent genetic and expression data implicate immunity in Alzheimer's disease

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    Background Late–onset Alzheimer's disease (AD) is heritable with 20 genes showing genome wide association in the International Genomics of Alzheimer's Project (IGAP). To identify the biology underlying the disease we extended these genetic data in a pathway analysis. Methods The ALIGATOR and GSEA algorithms were used in the IGAP data to identify associated functional pathways and correlated gene expression networks in human brain. Results ALIGATOR identified an excess of curated biological pathways showing enrichment of association. Enriched areas of biology included the immune response (p = 3.27×10-12 after multiple testing correction for pathways), regulation of endocytosis (p = 1.31×10-11), cholesterol transport (p = 2.96 × 10-9) and proteasome-ubiquitin activity (p = 1.34×10-6). Correlated gene expression analysis identified four significant network modules, all related to the immune response (corrected p 0.002 – 0.05). Conclusions The immune response, regulation of endocytosis, cholesterol transport and protein ubiquitination represent prime targets for AD therapeutics

    Type I interferon receptor signalling deficiency results in dysregulated innate immune responses to SARS-CoV-2 in mice

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    SARS-CoV-2 is a newly emerged coronavirus, causing the global pandemic of respiratory coronavirus disease (COVID-19). The type I interferon (IFN) pathway is of particular importance for anti-viral defense and recent studies identified that type I IFNs drive early inflammatory responses to SARS-CoV-2. Here, we use a mouse model of SARS-CoV-2 infection, facilitating viral entry by intranasal recombinant Adeno-Associated Virus (rAAV) transduction of hACE2 in wildtype (WT) and type I IFN receptor-1 deficient (Ifnar1–/–) mice, to study the role of type I IFN signalling and innate immune responses during SARS-CoV-2 infection. Our data show that type I IFN signalling is essential for inducing anti-viral effector responses to SARS-CoV-2, control of virus replication, and to prevent enhanced disease. Furthermore, hACE2-Ifnar1–/– mice had increased gene expression of the chemokine Cxcl1 and airway infiltration of neutrophils as well as reduced and delayed production of monocyte-recruiting chemokine CCL2. hACE2-Ifnar1–/– mice showed altered recruitment of inflammatory myeloid cells to the lung upon SARS-CoV-2 infection, with a shift from Ly6C+ to Ly6C– expressing cells. Together, our findings suggest that type I IFN signalling deficiency results in a dysregulated innate immune response to SARS-CoV-2 infection

    A Novel and Lethal De Novo LQT-3 Mutation in a Newborn with Distinct Molecular Pharmacology and Therapeutic Response

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    SCN5A encodes the alpha-subunit (Na(v)1.5) of the principle Na(+) channel in the human heart. Genetic lesions in SCN5A can cause congenital long QT syndrome (LQTS) variant 3 (LQT-3) in adults by disrupting inactivation of the Na(v)1.5 channel. Pharmacological targeting of mutation-altered Na(+) channels has proven promising in developing a gene-specific therapeutic strategy to manage specifically this LQTS variant. SCN5A mutations that cause similar channel dysfunction may also contribute to sudden infant death syndrome (SIDS) and other arrhythmias in newborns, but the prevalence, impact, and therapeutic management of SCN5A mutations may be distinct in infants compared with adults.Here, in a multidisciplinary approach, we report a de novo SCN5A mutation (F1473C) discovered in a newborn presenting with extreme QT prolongation and differential responses to the Na(+) channel blockers flecainide and mexiletine. Our goal was to determine the Na(+) channel phenotype caused by this severe mutation and to determine whether distinct effects of different Na(+) channel blockers on mutant channel activity provide a mechanistic understanding of the distinct therapeutic responsiveness of the mutation carrier. Sequence analysis of the proband revealed the novel missense SCN5A mutation (F1473C) and a common variant in KCNH2 (K897T). Patch clamp analysis of HEK 293 cells transiently transfected with wild-type or mutant Na(+) channels revealed significant changes in channel biophysics, all contributing to the proband's phenotype as predicted by in silico modeling. Furthermore, subtle differences in drug action were detected in correcting mutant channel activity that, together with both the known genetic background and age of the patient, contribute to the distinct therapeutic responses observed clinically.The results of our study provide further evidence of the grave vulnerability of newborns to Na(+) channel defects and suggest that both genetic background and age are particularly important in developing a mutation-specific therapeutic personalized approach to manage disorders in the young

    An Extrasynaptic GABA A

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    Construction and application of a self-care behavior intervention scheme for chronic heart failure patients based on interaction model of client health behavior

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    Abstract This study aimed to explore the impact and the effectiveness of interventions based on the Interaction Model of Client Health Behavior on the self-care behavior of chronic heart failure patients. Using convenience sampling, 80 chronic heart failure patients who met the inclusion and exclusion criteria were selected from the Cardiovascular Department of a tertiary hospital in Henan Province from January to June 2023. The first and second wards were randomly assigned to control and intervention groups, with the first ward serving as the control group and the second ward as the intervention group, each consisting of 40 cases. The control group received routine care, and the intervention group was subjected to a self-care behavior intervention scheme based on Interaction Model of Client Health Behavior. The intervention lasted for three months. Then, various indicators of the patients were assessed. The intervention group had significantly higher self-care behavior levels than the control group, significantly lower levels of disease perception than the control group, and the quality of life scores of the intervention group was lower than that of the control group. The difference in readmission rates between the two groups was statistically significant. The intervention scheme based on Interaction Model of Client Health Behavior can enhance self-care behavior in chronic heart failure patients, improve their disease perception, ameliorate their quality of life, and further decline readmission due to disease recurrence or complications

    Dopamine Release at Individual Presynaptic Terminals Visualized with FFNs

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    The nervous system transmits signals between neurons via neurotransmitter release during synaptic vesicle fusion. To observe neurotransmitter uptake and release from individual presynaptic terminals directly, we designed fluorescent false neurotransmitters as substrates for the synaptic vesicle monoamine transporter. Using these probes to image dopamine release in the striatum, we made several observations pertinent to synaptic plasticity. We found that the fraction of synaptic vesicles releasing neurotransmitter per stimulus was dependent on the stimulus frequency. A kinetically distinct "reserve" synaptic vesicle population was not observed under these experimental conditions. A frequency-dependent heterogeneity of presynaptic terminals was revealed that was dependent in part on D2 dopamine receptors, indicating a mechanism for frequency-dependent coding of presynaptic selection
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