124 research outputs found

    Characterization of early cortical population response to thalamocortical input in vitro

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    The in vitro thalamocortical slice preparation of mouse barrel cortex allows for stimulation of the cortex through its natural afferent thalamocortical pathway. This preparation was used here to investigate the first stage of cortical processing in the large postsynaptic dendritic networks as revealed by voltage sensitive dye imaging (VSDI). We identified the precise location and dimensions of two clearly distinguishable dendritic networks, one in the granular layer (GL) IV and one in the infragranular layer (IGL) V and VI and showed that they have different physiological properties. DiI fluorescent staining further revealed that thalamocortical axons project on to these two networks in the typical barrel like form, not only in the granular but also in the IGL. Finally we investigated the short-term dynamics of both the VSDI signal and the local field potential (LFP) in response to a train of eight-pulses at various frequencies in both these layers. We found evidence of differences in the plasticity between the first two response peaks compared to the remaining six peaks as well as differences in short-term plasticity between the VSDI response and the LFP. Our findings suggest, that at least early cortical processing takes place in two separate dendritic networks that may stand at the beginning of further parallel computation. The detailed characterization of the parameters of these networks may provide tools for further research into the complex dynamics of large dendritic networks and their role in cortical computation

    A multidisciplinary approach reveals an age-dependent expression of a novel bioactive peptide, already involved in neurodegeneration, in the postnatal rat forebrain

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    The basal forebrain has received much attention due to its involvement in multiple cognitive functions, but little is known about the basic neuronal mechanisms underlying its development, nor those mediating its primary role in Alzheimer’s disease. We have previously suggested that a novel 14-mer peptide, ‘T14’, could play a pivotal role in Alzheimer’s disease, via reactivation of a developmental signaling pathway. In this study, we have characterized T14 in the context of post-natal rat brain development, using a combination of different techniques. Ex-vivo rat brain slices containing the basal forebrain, at different stages of development, were used to investigate large-scale neuronal network activity in real time with voltage-sensitive dye imaging. Subsequent Western blot analysis revealed the expression profile of endogenous T14, its target alpha7 nicotinic receptor and the familiar markers of Alzheimer’s: amyloid beta and phosphorylated Tau. Results indicated maximal neuronal activity at the earliest ages during development, reflected in a concomitant profile of T14 peptide levels and related proteins. In conclusion, these findings show that the peptide, already implicated in neurodegenerative events, has an age-dependent expression, suggesting a possible contribution to the physiological mechanisms underlying brain maturation

    Practice nurse-supported weight self-management delivered within the national child immunisation programme for postnatal women:a feasibility cluster RCT

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    Background: Pregnancy is a high-risk time for excessive weight gain. The rising prevalence of obesity in women, combined with excess weight gain during pregnancy, means that there are more women with obesity in the postnatal period. This can have adverse health consequences for women in later life and increases the health risks during subsequent pregnancies. Objective: The primary aim was to produce evidence of whether or not a Phase III trial of a brief weight management intervention, in which postnatal women are encouraged by practice nurses as part of the national child immunisation programme to self-monitor their weight and use an online weight management programme, is feasible and acceptable. Design: The research involved a cluster randomised controlled feasibility trial and two semistructured interview studies with intervention participants and practice nurses who delivered the intervention. Trial data were collected at baseline and 3 months later. The interview studies took place after trial follow-up. Setting: The trial took place in Birmingham, UK. Participants: Twenty-eight postnatal women who were overweight/obese were recruited via Birmingham Women’s Hospital or general practices. Nine intervention participants and seven nurses were interviewed. Interventions: The intervention was delivered in the context of the national child immunisation programme. The intervention group were offered brief support that encouraged self-management of weight when they attended their practice to have their child immunised at 2, 3 and 4 months of age. The intervention involved the provision of motivation and support by nurses to encourage participants to make healthier lifestyle choices through self-monitoring of weight and signposting to an online weight management programme. The role of the nurse was to provide regular external accountability for weight loss. Women were asked to weigh themselves weekly and record this on a record card in their child’s health record (‘red book’) or using the online programme. The behavioural goal was for women to lose 0.5-1 kg per week. The usual-care group received a healthy lifestyle leaflet. Main outcome measures: The primary outcome was the feasibility of a Phase III trial to test the effectiveness of the intervention, as assessed against three traffic-light stop-go criteria (recruitment, adherence to regular self-weighing and registration with an online weight management programme). Results: The traffic-light criteria results were red for recruitment (28/80, 35% of target), amber for registration with the online weight loss programme (9/16, 56%) and green for adherence to weekly self-weighing (10/16, 63%). Nurses delivered the intervention with high fidelity. In the qualitative studies, participants indicated that the intervention was acceptable to them and they welcomed receiving support to lose weight at their child immunisation appointments. Although nurses raised some caveats to implementation, they felt that the intervention was easy to deliver and that it would motivate postnatal women to lose weight. Limitations: Fewer participants were recruited than planned. Conclusions: Although women and practice nurses responded well to the intervention and adherence to self-weighing was high, recruitment was challenging and there is scope to improve engagement with the intervention.Future work: Future research should focus on investigating other methods of recruitment and, thereafter, testing the effectiveness of the intervention.Trial registration: Current Controlled Trials ISRCTN12209332.Funding: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 49. See the NIHR Journals Library website for further project information.</p

    Upregulation of α7 Nicotinic Receptors by Acetylcholinesterase C-Terminal Peptides

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    BACKGROUND: The alpha-7 nicotinic acetylcholine receptor (alpha7-nAChR) is well known as a potent calcium ionophore that, in the brain, has been implicated in excitotoxicity and hence in the underlying mechanisms of neurodegenerative disorders such as Alzheimer's disease. Previous research implied that the activity of this receptor may be modified by exposure to a peptide fragment derived from the C-terminal region of the enzyme acetylcholinesterase. This investigation was undertaken to determine if the functional changes observed could be attributed to peptide binding interaction with the alpha7-nAChR, or peptide modulation of receptor expression. METHODOLOGY/PRINCIPAL FINDINGS: This study provides evidence that two peptides derived from the C-terminus of acetylcholinesterase, not only selectively displace specific bungarotoxin binding at the alpha7-nAChR, but also alter receptor binding properties for its familiar ligands, including the alternative endogenous agonist choline. Of more long-term significance, these peptides also induce upregulation of alpha7-nAChR mRNA and protein expression, as well as enhancing receptor trafficking to the plasma membrane. CONCLUSIONS/SIGNIFICANCE: The results reported here demonstrate a hitherto unknown relationship between the alpha7-nAChR and the non-enzymatic functions of acetylcholinesterase, mediated independently by its C-terminal domain. Such an interaction may prove valuable as a pharmacological tool, prompting new approaches for understanding, and combating, the process of neurodegeneration

    Upregulation of α7 Nicotinic Receptors by Acetylcholinesterase C-Terminal Peptides

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    BACKGROUND: The alpha-7 nicotinic acetylcholine receptor (alpha7-nAChR) is well known as a potent calcium ionophore that, in the brain, has been implicated in excitotoxicity and hence in the underlying mechanisms of neurodegenerative disorders such as Alzheimer's disease. Previous research implied that the activity of this receptor may be modified by exposure to a peptide fragment derived from the C-terminal region of the enzyme acetylcholinesterase. This investigation was undertaken to determine if the functional changes observed could be attributed to peptide binding interaction with the alpha7-nAChR, or peptide modulation of receptor expression. METHODOLOGY/PRINCIPAL FINDINGS: This study provides evidence that two peptides derived from the C-terminus of acetylcholinesterase, not only selectively displace specific bungarotoxin binding at the alpha7-nAChR, but also alter receptor binding properties for its familiar ligands, including the alternative endogenous agonist choline. Of more long-term significance, these peptides also induce upregulation of alpha7-nAChR mRNA and protein expression, as well as enhancing receptor trafficking to the plasma membrane. CONCLUSIONS/SIGNIFICANCE: The results reported here demonstrate a hitherto unknown relationship between the alpha7-nAChR and the non-enzymatic functions of acetylcholinesterase, mediated independently by its C-terminal domain. Such an interaction may prove valuable as a pharmacological tool, prompting new approaches for understanding, and combating, the process of neurodegeneration

    Considerations on Genre and Gender Conventions in Translating from Old English

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    The Old English poem The Wife's Lament is an extremely conventional and, at the same time, original text. It portrays a female character suffering for the absence of her loved one, through the framework of the so-called 'elegiac' style and a mainly heroic vocabulary. The traditional exile theme is, thus, interwoven with the uncommon motif of love sickness. While this appraisal of the poem is the most widely accepted one, disagreement still remains about the translation of some keywords, strictly related to the exile theme, such as sÄ«ĂŸ or wrĂŠcsÄ«ĂŸ. The aim of this paper is to examine diverging readings and glosses of the above mentioned 'exilic/elegiac' keywords, and to show that an accurate translation should not neglect a thorough appraisal of the text in its complexity and the association with related literary patterns and imagery in other poetic and prose texts

    The James Webb Space Telescope Mission

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    Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least 4m4m. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the 6.5m6.5m James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 years, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space Telescope Overview, 29 pages, 4 figure

    Teaching medical students basic neurotransmitter pharmacology using primary research resources

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    Teaching pharmacology to medical students has long been seen as a challenge, and one to which a number of innovative approaches have been taken. In this article, we describe and evaluate the use of primary research articles in teaching second-year medical students both in terms of the information learned and the use of the papers themselves. We designed a seminar where small groups of students worked on different neurotransmitters before contributing information to a plenary session. Student feedback suggested that when the information was largely novel, students learned considerably more. Crucially, this improvement in knowledge was seen even when they had not directly studied a particular transmitter in their work groups, suggesting a shared learning experience. Moreover, the majority of students reported that using primary research papers was easy and useful, with over half stating that they would use them in future study
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