35 research outputs found

    Potentiation of latent inhibition by haloperidol and clozapine is attenuated in Dopamine D2 receptor (Drd-2) deficient mice: Do antipsychotics influence learning to ignore irrelevant stimuli via both Drd-2 and non-Drd-2 mechanisms?

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    Whether the dopamine Drd-2 receptor is necessary for the behavioural action of antipsychotic drugs is an important question, as Drd-2 antagonism is responsible for their debilitating motor side effects. Using Drd-2 null mice (Drd2 -/-) it has previously been shown that Drd-2 is not necessary for antipsychotic drugs to reverse D-amphetamine disruption of latent inhibition (LI), a behavioural measure of learning to ignore irrelevant stimuli. Weiner's 'two-headed' model indicates that antipsychotics not only reverse LI disruption, 'disrupted LI', but also potentiate LI when low/absent in controls, 'persistent' LI. We investigated whether antipsychotic drugs haloperidol or clozapine potentiated LI in wild-type controls or Drd2 -/-. Both drugs potentiated LI in wild-type but not in Drd2 -/- mice, suggesting moderation of this effect of antipsychotics in the absence of Drd-2. Haloperidol potentiated LI similarly in both Drd1 -/- and wild-type mice, indicating no such moderation in Drd1 -/-. These data suggest that antipsychotic drugs can have either Drd-2 or non-Drd-2 effects on learning to ignore irrelevant stimuli, depending on how the abnormality is produced. Identification of the non-Drd-2 mechanism may help to identify novel non-Drd2 based therapeutic strategies for psychosis

    Falkland Island peatland development processes and the pervasive presence of fire

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    Acknowledgments RJP secured funding for this research from the Quaternary Research Association, University of York and the Russian Science Foundation (19-14-00102). We thank Paul Brickle and other members of the South Atlantic Environmental Research Institute for their help with logistics, David Large for valuable discussions about Falkland Islands peat and all landowners for access permission. This work is dedicated to Richard J. Payne who was tragically killed while climbing Peak 6477, a previously unclimbed subsidiary peak of Nanda Devi (Garhwal Himalayas) in May 2019. CRediT authorship contribution statement Dmitri Mauquoy: Conceptualization, Investigation, Writing - original draft, Writing - review & editing. Richard J. Payne: Conceptualization, Investigation. Kirill V. Babeshko: Investigation, Writing - original draft, Writing - review & editing. Rebecca Bartlett: Investigation, Writing - original draft, Writing - review & editing. Ian Boomer: Investigation. Hannah Bowey: Investigation. Chris D. Evans: Conceptualization, Writing - original draft, Writing - review & editing. Fin Ring-Hrubesh: Investigation. David Muirhead: Methodology, Investigation, Writing - original draft, Writing - review & editing. Matthew O’Callaghan: Investigation. Natalia Piotrowska: Investigation. Graham Rush: Investigation. Thomas Sloan: Investigation. Craig Smeaton: Methodology, Investigation, Writing - original draft. Andrey N. Tsyganov: Investigation, Writing - original draft, Writing - review & editing. Yuri A. Mazei: Investigation, Writing - original draft, Writing - review & editing.Peer reviewedPostprin

    The Case For A Victimology of Nonhuman Animal Harms

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    For the last twenty years 'victimology', the study of crime victims and victimisation has developed markedly. Like its 'parent' discipline of criminology, however, very little work has been done in this field around the notion of environmental victimisation. Like criminology itself, victimology has been almost exclusively anthropocentric in its outlook and indeed even more recent discussions of environmental victims - prompted by the development of green criminology - have failed to consider in any depth the victimisation of nonhuman animals. In this paper, we examine the shortfall in provision for and discussions of nonhuman animal victims with reference to Christie's (1986) notion of the 'ideal victim' and Boutellier's concept of the 'victimalization of morality'. We argue that as victimology has increasingly embraced concepts of victimisation based on 'social harms' rather than strict legalistic categorises, its rejection of nonhuman victims from the ambit of study is no longer conceptually or philosophically justified

    Genetic correlation between amyotrophic lateral sclerosis and schizophrenia

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    A. Palotie on työryhmän Schizophrenia Working Grp Psychiat jäsen.We have previously shown higher-than-expected rates of schizophrenia in relatives of patients with amyotrophic lateral sclerosis (ALS), suggesting an aetiological relationship between the diseases. Here, we investigate the genetic relationship between ALS and schizophrenia using genome-wide association study data from over 100,000 unique individuals. Using linkage disequilibrium score regression, we estimate the genetic correlation between ALS and schizophrenia to be 14.3% (7.05-21.6; P = 1 x 10(-4)) with schizophrenia polygenic risk scores explaining up to 0.12% of the variance in ALS (P = 8.4 x 10(-7)). A modest increase in comorbidity of ALS and schizophrenia is expected given these findings (odds ratio 1.08-1.26) but this would require very large studies to observe epidemiologically. We identify five potential novel ALS-associated loci using conditional false discovery rate analysis. It is likely that shared neurobiological mechanisms between these two disorders will engender novel hypotheses in future preclinical and clinical studies.Peer reviewe

    Global respiratory syncytial virus–related infant community deaths

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    Background Respiratory syncytial virus (RSV) is a leading cause of pediatric death, with >99% of mortality occurring in low- and lower middle-income countries. At least half of RSV-related deaths are estimated to occur in the community, but clinical characteristics of this group of children remain poorly characterized. Methods The RSV Global Online Mortality Database (RSV GOLD), a global registry of under-5 children who have died with RSV-related illness, describes clinical characteristics of children dying of RSV through global data sharing. RSV GOLD acts as a collaborative platform for global deaths, including community mortality studies described in this supplement. We aimed to compare the age distribution of infant deaths <6 months occurring in the community with in-hospital. Results We studied 829 RSV-related deaths <1 year of age from 38 developing countries, including 166 community deaths from 12 countries. There were 629 deaths that occurred <6 months, of which 156 (25%) occurred in the community. Among infants who died before 6 months of age, median age at death in the community (1.5 months; IQR: 0.8−3.3) was lower than in-hospital (2.4 months; IQR: 1.5−4.0; P < .0001). The proportion of neonatal deaths was higher in the community (29%, 46/156) than in-hospital (12%, 57/473, P < 0.0001). Conclusions We observed that children in the community die at a younger age. We expect that maternal vaccination or immunoprophylaxis against RSV will have a larger impact on RSV-related mortality in the community than in-hospital. This case series of RSV-related community deaths, made possible through global data sharing, allowed us to assess the potential impact of future RSV vaccines

    Estimation of Genetic Correlation via Linkage Disequilibrium Score Regression and Genomic Restricted Maximum Likelihood

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    J. Lönnqvist on työryhmän Psychiat Genomics Consortium jäsen.Genetic correlation is a key population parameter that describes the shared genetic architecture of complex traits and diseases. It can be estimated by current state-of-art methods, i.e., linkage disequilibrium score regression (LDSC) and genomic restricted maximum likelihood (GREML). The massively reduced computing burden of LDSC compared to GREML makes it an attractive tool, although the accuracy (i.e., magnitude of standard errors) of LDSC estimates has not been thoroughly studied. In simulation, we show that the accuracy of GREML is generally higher than that of LDSC. When there is genetic heterogeneity between the actual sample and reference data from which LD scores are estimated, the accuracy of LDSC decreases further. In real data analyses estimating the genetic correlation between schizophrenia (SCZ) and body mass index, we show that GREML estimates based on similar to 150,000 individuals give a higher accuracy than LDSC estimates based on similar to 400,000 individuals (from combinedmeta-data). A GREML genomic partitioning analysis reveals that the genetic correlation between SCZ and height is significantly negative for regulatory regions, which whole genome or LDSC approach has less power to detect. We conclude that LDSC estimates should be carefully interpreted as there can be uncertainty about homogeneity among combined meta-datasets. We suggest that any interesting findings from massive LDSC analysis for a large number of complex traits should be followed up, where possible, with more detailed analyses with GREML methods, even if sample sizes are lesser.Peer reviewe

    Interaction Testing and Polygenic Risk Scoring to Estimate the Association of Common Genetic Variants with Treatment Resistance in Schizophrenia

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    Importance: About 20% to 30% of people with schizophrenia have psychotic symptoms that do not respond adequately to first-line antipsychotic treatment. This clinical presentation, chronic and highly disabling, is known as treatment-resistant schizophrenia (TRS). The causes of treatment resistance and their relationships with causes underlying schizophrenia are largely unknown. Adequately powered genetic studies of TRS are scarce because of the difficulty in collecting data from well-characterized TRS cohorts. Objective: To examine the genetic architecture of TRS through the reassessment of genetic data from schizophrenia studies and its validation in carefully ascertained clinical samples. Design, Setting, and Participants: Two case-control genome-wide association studies (GWASs) of schizophrenia were performed in which the case samples were defined as individuals with TRS (n = 10501) and individuals with non-TRS (n = 20325). The differences in effect sizes for allelic associations were then determined between both studies, the reasoning being such differences reflect treatment resistance instead of schizophrenia. Genotype data were retrieved from the CLOZUK and Psychiatric Genomics Consortium (PGC) schizophrenia studies. The output was validated using polygenic risk score (PRS) profiling of 2 independent schizophrenia cohorts with TRS and non-TRS: a prevalence sample with 817 individuals (Cardiff Cognition in Schizophrenia [CardiffCOGS]) and an incidence sample with 563 individuals (Genetics Workstream of the Schizophrenia Treatment Resistance and Therapeutic Advances [STRATA-G]). Main Outcomes and Measures: GWAS of treatment resistance in schizophrenia. The results of the GWAS were compared with complex polygenic traits through a genetic correlation approach and were used for PRS analysis on the independent validation cohorts using the same TRS definition. Results: The study included a total of 85490 participants (48635 [56.9%] male) in its GWAS stage and 1380 participants (859 [62.2%] male) in its PRS validation stage. Treatment resistance in schizophrenia emerged as a polygenic trait with detectable heritability (1% to 4%), and several traits related to intelligence and cognition were found to be genetically correlated with it (genetic correlation, 0.41-0.69). PRS analysis in the CardiffCOGS prevalence sample showed a positive association between TRS and a history of taking clozapine (r2 = 2.03%; P =.001), which was replicated in the STRATA-G incidence sample (r2 = 1.09%; P =.04). Conclusions and Relevance: In this GWAS, common genetic variants were differentially associated with TRS, and these associations may have been obscured through the amalgamation of large GWAS samples in previous studies of broadly defined schizophrenia. Findings of this study suggest the validity of meta-analytic approaches for studies on patient outcomes, including treatment resistance

    Fibrotic Changes to Schlemm’s Canal Endothelial Cells in Glaucoma

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    Previous studies have shown that glaucomatous Schlemm’s canal endothelial cells (gSCECs) are stiffer and associated with reduced porosity and increased extracellular matrix (ECM) material compared to SCECs from healthy individuals. We hypothesised that Schlemm’s canal (SC) cell stiffening was a function of fibrotic changes occurring at the inner wall of SC in glaucoma. This study was performed in primary cell cultures isolated from the SC lumen of human donor eyes. RNA and protein quantification of both fibrotic and endothelial cell markers was carried out on both healthy and gSCECs. Functional assays to assess cell density, size, migration, proliferation, and mitochondrial function of these cells were also carried out. Indeed, we found that gSCECs deviate from typical endothelial cell characteristics and exhibit a more fibrotic phenotype. For example, gSCECs expressed significantly higher protein levels of the fibrotic markers α-SMA, collagen I-α1, and fibronectin, as well as significantly increased protein expression of TGFβ-2, the main driver of fibrosis, compared to healthy SCECs. Interestingly, we observed a significant increase in protein expression of endothelial marker VE-cadherin in gSCECs, compared to healthy SCECs. gSCECs also appeared to be significantly larger, and surprisingly proliferate and migrate at a significantly higher rate, as well as showing significantly reduced mitochondrial activity, compared to healthy SCECs
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