341 research outputs found

    Proteinase-activated receptor 2 is involved in the behavioural changes associated with sickness behaviour

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    Proteinase-activated receptor-2 (PAR2) is widely expressed in the CNS but whether it plays a key role in inflammation-related behavioural changes remains unknown. Hence, in the present study we have examined whether PAR2 contributes to behaviour associated with systemic inflammation using PAR2 transgenic mice. The onset of sickness behaviour was delayed and the recovery accelerated in PAR2-/- mice in the LPS-induced model of sickness behaviour. In contrast, PAR2 does not contribute to behaviour under normal conditions. In conclusion, these data suggest that PAR2 does not contribute to behaviour in the normal healthy brain but it plays a role in inflammation-related behavioural changes

    Temporal dissociation of phencyclidine: Induced locomotor and social alterations in rats using an automated homecage monitoring system – implications for the 3Rs and preclinical drug discovery

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    Background: Rodent behavioural assays are widely used to delineate the mechanisms of psychiatric disorders and predict the efficacy of drug candidates. Conventional behavioural paradigms are restricted to short time windows and involve transferring animals from the homecage to unfamiliar apparatus which induces stress. Additionally, factors including environmental perturbations, handling and the presence of an experimenter can impact behaviour and confound data interpretation. To improve welfare and reproducibility these issues must be resolved. Automated homecage monitoring offers a more ethologically relevant approach with reduced experimenter bias. Aim: To evaluate the effectiveness of an automated homecage system at detecting locomotor and social alterations induced by phencyclidine (PCP) in group-housed rats. PCP is an NMDA receptor antagonist commonly utilised to model aspects of schizophrenia. Methods: Rats housed in groups of 3 were implanted with radio frequency identification (RFID) tags. Each homecage was placed over a RFID reader baseplate for the automated monitoring of the social and locomotor activity of each individual rat. For all rats, we acquired homecage data for 24 h following administration of both saline and PCP (2.5 mg/kg). Results: PCP resulted in significantly increased distance travelled from 15 to 60 min post injection. Furthermore, PCP significantly enhanced time spent isolated from cage-mates and this asociality lasted from 60 to 105 min post treatment. Conclusions: Unlike conventional assays, in-cage monitoring captures the temporal duration of drug effects on multiple behaviours in the same group of animals. This approach could benefit psychiatric preclinical drug discovery though improved welfare and increased between-laboratory replicability

    Disruption of the Zdhhc9 intellectual disability gene leads to behavioural abnormalities in a mouse

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    Protein S-acylation is a widespread post-translational modification that regulates the trafficking and function of a diverse array of proteins. This modification is catalysed by a family of twenty-three zDHHC enzymes that exhibit both specific and overlapping substrate interactions. Mutations in the gene encoding zDHHC9 cause mild-to-moderate intellectual disability, seizures, speech and language impairment, hypoplasia of the corpus callosum and reduced volume of sub-cortical structures. In this study, we have undertaken behavioural phenotyping, magnetic resonance imaging (MRI) and isolation of S-acylated proteins to investigate the effect of disruption of the Zdhhc9 gene in mice in a C57BL/6 genetic background. Zdhhc9 mutant male mice exhibit a range of abnormalities compared with their wild-type littermates: altered behaviour in the open-field test, elevated plus maze and acoustic startle test that is consistent with a reduced anxiety level; a reduced hang time in the hanging wire test that suggests underlying hypotonia but which may also be linked to reduced anxiety; deficits in the Morris water maze test of hippocampal-dependent spatial learning and memory; and a 36% reduction in corpus callosum volume revealed by MRI. Surprisingly, membrane association and S-acylation of H-Ras was not disrupted in either whole brain or hippocampus of Zdhhc9 mutant mice, suggesting that other substrates of this enzyme are linked to the observed changes. Overall, this study highlights a key role for zDHHC9 in brain development and behaviour, and supports the utility of the Zdhhc9 mutant mouse line to investigate molecular and cellular changes linked to intellectual disability and other deficits in the human population

    Mitogen-activated protein kinase phosphatase-2 deletion impairs synaptic plasticity and hippocampal-dependent memory

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    Mitogen-activated protein kinases (MAPKs) regulate brain function and their dysfunction is implicated in a number of brain disorders, including Alzheimer’s disease. Thus there is great interest in understanding the signalling systems that control MAPK function. One family of proteins that contribute to this process, the mitogen-activated protein kinase phosphatases (MKPs), directly inactivate MAPKs through dephosphorylation. Recent studies have identified novel functions of MKPs in development, the immune system and cancer. However, a significant gap in our knowledge remains in relation to their role in brain functioning. Here, using transgenic mice where the Dusp4 gene encoding MKP-2 has been knocked out (MKP-2-/- mice), we show that long-term potentiation (LTP) is impaired in MKP-2-/- mice compared to MKP-2+/+ controls whereas neuronal excitability, evoked synaptic transmission and paired-pulse facilitation remain unaltered. Furthermore, spontaneous excitatory postsynaptic currents (sEPSC) frequency was increased in acute slices and primary hippocampal cultures prepared from MKP-2-/- mice with no effect on EPSC amplitude observed. An increase in synapse number was evident in primary hippocampal cultures which may account for the increase in spontaneous EPSC frequency. In addition no change in ERK activity was detected in both brain tissue and primary hippocampal cultures, suggesting that the effects of MKP-2 deletion were MAPK independent. Consistent with these alterations in hippocampal function, MKP-2-/- mice show deficits in spatial reference and working memory when investigated using the Morris water maze. These data show that MKP-2 plays a role in regulating hippocampal function and that this effect may be independent of MAPK signalling

    Mitogen-activated protein kinase phosphatase-2 deletion modifies ventral tegmental area function and connectivity and alters reward processing

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    Mitogen-activated protein kinases (MAPKs) regulate normal brain functioning, and their dysfunction is implicated in a number of brain disorders. Thus, there is great interest in understanding the signalling systems that control MAPK functioning. One family of proteins that contribute to this process, the mitogen-activated protein kinase phosphatases (MKPs), directly inactivate MAPKs through dephosphorylation. Recent studies have identified novel functions of MKPs in foetal development, the immune system, cancer and synaptic plasticity and memory. In the present study, we performed an unbiased investigation using MKP-2-/- mice to assess whether MKP-2 plays a global role in modulating brain function. Local cerebral glucose utilization is significantly increased in the ventral tegmental area (VTA) of MKP-2-/- mice, with connectivity analysis revealing alterations in VTA functional connectivity, including a significant reduction in connectivity to the nucleus accumbens and hippocampus. In addition, spontaneous excitatory postsynaptic current frequency, but not amplitude, onto putative dopamine neurons in the VTA is increased in MKP-2-/- mice, which indicates that increased excitatory drive may account for the increased VTA glucose utilization. Consistent with modified VTA function and connectivity, in behavioural tests MKP-2-/- mice exhibited increased sucrose preference and impaired amphetamine-induced hyperlocomotion. Overall, these data reveal that MKP-2 plays a role in modulating VTA function and that its dysfunction may contribute to brain disorders in which altered reward processing is present

    Reflecting to Rebuild and Strengthen Professional Development A Collection of ‘Post-Online’ Conversations

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    The file attached to this record is the author's versionThis monograph is a multi-authored collection consisting of our faculty’s post-online reflections. The objective was to gather thoughts and discussion around teaching and research during COVID-19. We aim to build and explore around ‘lived experiences’ to provide a reference point to help Continuous Professional Learning and Development (CPLD) activities. The section on ‘digital diaries’ consists of dialogues from staff categorised into varied themes. In the testimonies, staff have reflected around their challenges, targets, strengths, familiarity and how they managed to overcome difficulties and achieve goals. A special section, from the Centre for Urban Research on Austerity (CURA), is devoted to identifying how pandemic has intensified research challenges, highlighting the funding, time and location constraints on academic research

    Report of the Lancet Commission on the Value of Death: bringing death back into life

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    The story of dying in the 21st century is a story of paradox. While many people are overtreated in hospitals with families and communities relegated to the margins, still more remain undertreated, dying of preventable conditions and without access to basic pain relief. The unbalanced and contradictory picture of death and dying is the basis for this Commission

    Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

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    The inclusive and dijet production cross-sections have been measured for jets containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The measurements use data corresponding to an integrated luminosity of 34 pb^-1. The b-jets are identified using either a lifetime-based method, where secondary decay vertices of b-hadrons in jets are reconstructed using information from the tracking detectors, or a muon-based method where the presence of a muon is used to identify semileptonic decays of b-hadrons inside jets. The inclusive b-jet cross-section is measured as a function of transverse momentum in the range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet cross-section is measured as a function of the dijet invariant mass in the range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets and the angular variable chi in two dijet mass regions. The results are compared with next-to-leading-order QCD predictions. Good agreement is observed between the measured cross-sections and the predictions obtained using POWHEG + Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet cross-section. However, it does not reproduce the measured inclusive cross-section well, particularly for central b-jets with large transverse momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final version published in European Physical Journal

    Search for displaced vertices arising from decays of new heavy particles in 7 TeV pp collisions at ATLAS

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    We present the results of a search for new, heavy particles that decay at a significant distance from their production point into a final state containing charged hadrons in association with a high-momentum muon. The search is conducted in a pp-collision data sample with a center-of-mass energy of 7 TeV and an integrated luminosity of 33 pb^-1 collected in 2010 by the ATLAS detector operating at the Large Hadron Collider. Production of such particles is expected in various scenarios of physics beyond the standard model. We observe no signal and place limits on the production cross-section of supersymmetric particles in an R-parity-violating scenario as a function of the neutralino lifetime. Limits are presented for different squark and neutralino masses, enabling extension of the limits to a variety of other models.Comment: 8 pages plus author list (20 pages total), 8 figures, 1 table, final version to appear in Physics Letters
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