19 research outputs found

    Neuronal correlates of metacognition in primate frontal cortex

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    We spend a large portion of life as the object of our own thoughts. Daily we reflect on all sorts of recent and not so recent decisions, and the products of those reflective thoughts serve to guide future goals, actions, and thoughts. The process of "thinking about thinking", or metacognition, has garnered scrutiny in psychology studies for decades and recently in some imaging and neurological studies, but its neuronal basis remains unknown. Moreover, metacognition is largely thought a uniquely human ability, and only very recently has some evidence suggested other species may harbor metacognitive skills. To begin investigating neuronal mechanisms underlying metacognition, we performed two experiments.First, we tested whether rhesus macaques exhibited evidence for metacognition. We trained monkeys to perform a visual oculomotor metacognition task. In each trial, monkeys made a decision then made a bet. To earn maximum reward, monkeys had to monitor their decision and then make a bet to indicate whether the decision was correct or incorrect. We found the monkeys' behavior was best explained by a metacognitive strategy, and we ruled out possible alternative strategies to perform the task such as reliance on visual stimuli or saccadic reaction times.Second, we tested whether neurons exhibited activity correlated with metacognition. While monkeys performed the task we recorded from single neurons in three frontal cortical areas known to play roles in higher cognitive functions: the frontal eye field, lateral prefrontal cortex, and the supplementary eye field. Our predictions were that frontal eye field neuronal activity would correlate with making the decisions but not the bets, and that lateral prefrontal cortex and supplementary eye field neuronal activity would correlate with linking the decisions to the bets - the putative metacognitive signals. We found signals in all three brain areas correlated with making decisions and correlated with making bets. The supplementary eye field was the only area of the three that exhibited strong signals correlated with metacognitive monitoring, and these signals appeared early and were sustained throughout the task. Our results identify the supplementary eye field as a likely contributor to metacognitive monitoring

    IMI - Myopia Genetics Report

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    The knowledge on the genetic background of refractive error and myopia has expanded dramatically in the past few years. This white paper aims to provide a concise summary of current genetic findings and defines the direction where development is needed. We performed an extensive literature search and conducted informal discussions with key stakeholders. Specific topics reviewed included common refractive error, any and high myopia, and myopia related to syndromes. To date, almost 200 genetic loci have been identified for refractive error and myopia, and risk variants mostly carry low risk but are highly prevalent in the general population. Several genes for secondary syndromic myopia overlap with those for common myopia. Polygenic risk scores show overrepresentation of high myopia in the higher deciles of risk. Annotated genes have a wide variety of functions, and all retinal layers appear to be sites of expression. The current genetic findings offer a world of new molecules involved in myopiagenesis. As the missing heritability is still large, further genetic advances are needed. This Committee recommends expanding large-scale, in-depth genetic studies using complementary big data analytics, consideration of gene-environment effects by thorough measurement of environmental exposures, and focus on subgroups with extreme phenotypes and high familial occurrence. Functional characterization of associated variants is simultaneously needed to bridge the knowledge gap between sequence variance and consequence for eye growth

    Identification of a novel susceptibility locus at 13q34 and refinement of the 20p12.2 region as a multi-signal locus associated with bladder cancer risk in individuals of european ancestry

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    Candidate gene and genome-wide association studies (GWAS) have identified 15 independent genomic regions associated with bladder cancer risk. In search for additional susceptibility variants, we followed up on four promising single-nucleotide polymorphisms (SNPs) that had not achieved genome-wide significance in 6911 cases and 11 814 controls (rs6104690, rs4510656, rs5003154 and rs4907479, P < 1 7 10(-6)), using additional data from existing GWAS datasets and targeted genotyping for studies that did not have GWAS data. In a combined analysis, which included data on up to 15 058 cases and 286 270 controls, two SNPs achieved genome-wide statistical significance: rs6104690 in a gene desert at 20p12.2 (P = 2.19 7 10(-11)) and rs4907479 within the MCF2L gene at 13q34 (P = 3.3 7 10(-10)). Imputation and fine-mapping analyses were performed in these two regions for a subset of 5551 bladder cancer cases and 10 242 controls. Analyses at the 13q34 region suggest a single signal marked by rs4907479. In contrast, we detected two signals in the 20p12.2 region-the first signal is marked by rs6104690, and the second signal is marked by two moderately correlated SNPs (r(2) = 0.53), rs6108803 and the previously reported rs62185668. The second 20p12.2 signal is more strongly associated with the risk of muscle-invasive (T2-T4 stage) compared with non-muscle-invasive (Ta, T1 stage) bladder cancer (case-case P 64 0.02 for both rs62185668 and rs6108803). Functional analyses are needed to explore the biological mechanisms underlying these novel genetic associations with risk for bladder cancer

    Identification of a novel susceptibility locus at 13q34 and refinement of the 20p12.2 region as a multi-signal locus associated with bladder cancer risk in individuals of european ancestry

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    A new polygenic score for refractive error improves detection of children at risk of high myopia but not the prediction of those at risk of myopic macular degeneration

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    Background High myopia (HM), defined as a spherical equivalent refractive error (SER) ≤ −6.00 diopters (D), is a leading cause of sight impairment, through myopic macular degeneration (MMD). We aimed to derive an improved polygenic score (PGS) for predicting children at risk of HM and to test if a PGS is predictive of MMD after accounting for SER. Methods The PGS was derived from genome-wide association studies in participants of UK Biobank, CREAM Consortium, and Genetic Epidemiology Research on Adult Health and Aging. MMD severity was quantified by a deep learning algorithm. Prediction of HM was quantified as the area under the receiver operating curve (AUROC). Prediction of severe MMD was assessed by logistic regression. Findings In independent samples of European, African, South Asian and East Asian ancestry, the PGS explained 19% (95% confidence interval 17–21%), 2% (1–3%), 8% (7–10%) and 6% (3–9%) of the variation in SER, respectively. The AUROC for HM in these samples was 0.78 (0.75–0.81), 0.58 (0.53–0.64), 0.71 (0.69–0.74) and 0.67 (0.62–0.72), respectively. The PGS was not associated with the risk of MMD after accounting for SER: OR = 1.07 (0.92–1.24). Interpretation Performance of the PGS approached the level required for clinical utility in Europeans but not in other ancestries. A PGS for refractive error was not predictive of MMD risk once SER was accounted fo

    McCurtain Gazette

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    Semiweekly newspaper from Idabel, Oklahoma that includes local, state, and national news along with advertising

    Procedure for Selecting Monoclonal Antibodies for Use in a Ligand Displacement Assay of Serum Antibody Levels

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    Monoclonal antibodies for use in a ligand displacement assay were selected for specificity and affinity/avidity properties that result in their release and displacement in the presence of specific sample antibody but not in the presence of antibodies against other antigens. A screening process is described which involves measurement of displacement of antibody by an ELISA procedure using an enzyme labeled anti-immunoglobulin, providing a means of demonstrating usefulness of a candidate antibody in a ligand displacement format without necessitating the production of enzyme conjugates of each candidate antibody to be screened. The procedure was used to screen a set of eleven monoclonal antibodies (initially selected for anti-Trichinella spiralis specificity by conventional screening methods), and successfully discriminated between antibodies which were useful in the ligand displacement format and those which were not

    NMDA Receptor Antagonists Reveal Age-Dependent Differences in the Properties of Visual Cortical Plasticity

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    The suggestion that NMDA receptor (NMDAR)-dependent plasticity is subunit specific, with NR2B-types required for long-term depression (LTD) and NR2A-types critical for the induction of long-term potentiation (LTP), has generated much attention and considerable debate. By investigating the suggested subunit-specific roles of NMDARs in the mouse primary visual cortex over development, we report several important findings that clarify the roles of NMDAR subtypes in synaptic plasticity. We observed that LTD was not attenuated by application of ifenprodil, an NR2B-type antagonist, or NVP-AAM007, a less selective NR2A-type antagonist. However, we were surprised that NVP-AAM007 completely blocked adult LTP (postnatal day (P) 45–90), while only modestly affecting juvenile LTP (P21-28). To assess whether this developmental transition reflected an increasing role for NR2A-type receptors with maturity, we characterized the specificity of NVP-AAM007. We found not only that NVP-AAM007 lacks discernable subunit specificity but also that the effects of NVP-AAM077 on LTP could be mimicked using subsaturating concentrations of APV, a global NMDAR antagonist. These results indicate that the effects of NVP-AAM077 on synaptic plasticity are largely explained by nonspecific blockade of NMDARs. Moreover our findings are the first to reveal a developmental increase in the sensitivity of LTP to NMDAR antagonism. We suggest that discrepant reports describing the effect of NVP-AAM077 on LTP may be partially explained by this developmental shift in the properties of LTP. These results indicate that the degree of NMDAR activation required for LTP increases with development, providing insight into a novel underlying mechanism governing the properties of synaptic plasticity
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