Biology subjects

Pereira, M.

Publications and source records attributed to Pereira, M..

At least 37 records · Page 2Linked to original sources

bioRxiv2023

Cardiac atrophy, dysfunction, and metabolic impairments: a cancer-induced heart failure phenotype

Muscle atrophy and weakness are prevalent features of cancer. While extensive research has characterized skeletal muscle wasting in cancer cachexia, limited studies have investigated how cardiac structure and function are affected by therapy-naive cancer. In cell-based models of orthotopic, syngeneic epithelial ovarian cancer (EOC) and pancreatic ductal adenocarcinoma (PDAC), and a patient-derived pancreatic xenograft model (PDX), we evaluated cardiac structure, function, and metabolism. Tumor-bearing mice showed cardiac atrophy and intrinsic systolic and diastolic dysfunction; associated with hypotension and exercise intolerance. In hearts of ovarian tumor-bearing mice, fatty acid-supported mitochondrial respiration decreased and carbohydrate-supported respiration increased, establishing a substrate shift in cardiac metabolism that is characteristic of heart failure. EOC decreased cytoskeletal and cardioprotective gene expression, which was paralleled by downregulation of transcription factors that regulate cardiomyocyte size and function. PDX tumors altered myosin heavy chain isoform expression - a molecular phenotype observed in heart failure. Markers of autophagy and ubiquitin-proteasome system were upregulated with cancer, providing evidence of catabolic signaling that promotes cardiac wasting. Together, metabolic stress, cardiac gene dysregulation, and upregulation of catabolic pathways contribute to cardiac atrophy and failure during cancer. Finally, we demonstrate that pathological cardiac remodeling is induced by human cancer, providing translational evidence of cancer-induced cardiomyopathy.

physiology↗

bioRxiv2023

Influenza A virus activates the unfolded protein response and induces the accumulation of insoluble protein aggregates that are essential for efficient viral propagation

Influenza A virus (IAV) is one of the main causes of annual respiratory epidemics in humans. IAV employs multiple strategies to evade host immunity and hijack cellular mechanisms to support proper virion formation and propagation. Some of these strategies encompass the manipulation of pathways involved in protein homeostasis, leading to changes in the host proteome and protein distribution within the cell. In this study, we performed a detailed analysis of the interplay between IAV and the host cells proteostasis mechanisms throughout the entire infectious cycle. We reveal that IAV infection induces the activation of the inositol requiring enzyme 1 (IRE1) branch of the unfolded protein response (UPR), at an infection stage that coincides with high rates of viral protein translation. This activation is particularly important for infection, as attenuation of virus production was observed upon IRE1 inhibition. Concomitantly to UPR activation, we observed the accumulation of virus-induced insoluble protein aggregates, which contain both viral and host proteins and are associated with a dysregulation of the host cell RNA metabolism. We demonstrate that this accumulation is important for IAV propagation, as its prevention using a quinoline-steroid hybrid compound significantly reduces the number of produced infectious virus particles. Our data suggests that the formation of these insoluble protein aggregates favors the final steps of the infection cycle, more specifically the virion assembly. Our findings reveal additional mechanisms by which IAV disrupts the host cell proteostasis to favor infection and uncover new cellular targets that can be explored for the development of host-directed antiviral strategies.

microbiology↗

bioRxiv2023

Divergent associations of slow-wave sleep vs. REM sleep with plasma amyloid-beta

BackgroundRecent evidence shows that during slow-wave sleep (SWS), the brain is cleared from potentially toxic metabolites, such as the amyloid-beta protein. Poor sleep or elevated cortisol levels can worsen amyloid-beta clearance, potentially leading to the formation of amyloid plaques, a neuropathological hallmark of Alzheimers disease. Here, we explore how nocturnal neural and endocrine activity affects amyloid-beta fluctuations in the peripheral blood as a reflection of cerebral clearance. MethodsSimultaneous polysomnography and all-night blood sampling were acquired in 60 healthy volunteers aged 20-68 years old. Nocturnal plasma concentrations of two amyloid-beta species (amyloid-beta-40 and amyloid-beta-42), cortisol, and growth hormone were assessed every 20 minutes from 23:00-7:00. Amyloid-beta fluctuations were modeled with sleep stages, (non)-oscillatory power, and hormones as predictors while controlling for age and multiple comparisons. Time lags between the predictors and amyloid-beta ranged from 20 to 120min. FindingsThe amyloid-beta-40 and amyloid-beta-42 levels correlated positively with growth hormone concentrations, SWS proportion, slow-wave (0.3-4Hz) oscillatory and high-band (30-48Hz) non-oscillatory power, but negatively with cortisol concentrations and rapid eye movement sleep (REM) proportion measured 40-100min before (all t-values>|3|, p-values<0.003). Older participants showed higher amyloid-beta-40 levels. InterpretationSlow-wave oscillations are associated with higher plasma amyloid-beta levels, reflecting their contribution to cerebral amyloid-beta clearance across the blood-brain barrier. REM sleep is related to decreased amyloid-beta plasma levels; however, this link may reflect passive aftereffects of SWS and not REMs effects per se. Strong associations between cortisol, growth hormone, and amyloid-beta presumably reflect the sleep-regulating role of the corresponding releasing hormones. A positive association between age and amyloid-beta-40 may indicate that peripheral clearance becomes less efficient with age. Our study provides important insights into the specificity of different sleep features effects on brain clearance and suggests that cortisol nocturnal fluctuations may serve as a new marker of clearance efficiency.

neuroscience↗

bioRxiv2023

Amyloid pathology reduces ELP3 expression and tRNA modifications leading to impaired proteostasis in Alzheimer's disease models

Alzheimers Disease (AD) is a progressive and irreversible neurodegenerative disorder, characterized by the accumulation of abeta-amyloid aggregates, which triggers tau hyperphosphorylation and neuronal loss. While the precise mechanisms underlying neurodegeneration in AD are not entirely understood, it is known that loss of proteostasis is implicated in this process. Maintaining neuronal proteostasis requires proper transfer RNA (tRNA) modifications, which are crucial for optimal translation. However, research into tRNA epitranscriptome in AD is limited, and it is not yet clear how alterations in tRNA modifying enzymes and tRNA modifications might contribute to disease progression. Here, we report that expression of the tRNA modifying enzyme ELP3 is reduced in the brain of AD patients and amyloid AD mouse models, suggesting ELP3 is implicated in proteostasis dysregulation observed in AD. To investigate the role of ELP3 specifically in neuronal proteostasis impairments in the context of amyloid pathology, we analyzed SH-SY5Y neuronal cells carrying the amyloidogenic Swedish familial AD mutation in the APP gene (SH-SWE) or the wild-type gene (SH-WT). Similarly to the amyloid mouse models, SH-SWE exhibited reduced levels of ELP3 which was associated with tRNA hypomodifications and reduced abundance, as well as proteostasis impairments. Furthermore, the knock-down of ELP3 in SH-WT recapitulated the proteostasis impairments observed in SH-SWE cells. Importantly, the correction of tRNA deficits due to ELP3 reduction rescued and reverted proteostasis impairments of SH-SWE and SH-WT knock-down for ELP3, respectively. Additionally, SH-WT exposed to the secretome of SH-SWE or synthetic amyloid aggregates recapitulate the SH-SWE phenotype, characterized by reduced ELP3 expression, tRNA hypomodification and increased protein aggregation. Taken together, our data suggest that amyloid pathology dysregulates neuronal proteostasis through the reduction of ELP3 and tRNA modifications. This study highlights the modulation of tRNA modifications as a potential therapeutic avenue to restore neuronal proteostasis in AD and preserve neuronal function. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=112 SRC="FIGDIR/small/538928v2_ufig1.gif" ALT="Figure 1"> View larger version (44K): org.highwire.dtl.DTLVardef@ed5cf4org.highwire.dtl.DTLVardef@171b14aorg.highwire.dtl.DTLVardef@12eb19dorg.highwire.dtl.DTLVardef@8ed4ab_HPS_FORMAT_FIGEXP M_FIG C_FIG

molecular biology↗

bioRxiv2023

Comparative analysis of syngeneic mouse models of high-grade serous ovarian cancer

Ovarian cancers often exhibit high rates of recurrence and poor treatment response. Preclinical models that recapitulate the heterogeneity of human disease are critical to develop new therapeutic approaches. While patient-derived models are a powerful tool for testing various therapeutics, their dependence on immune-compromised mice is severely limiting. Syngeneic mouse models, however, allow for the generation of tumours comprising the full repertoire of non-malignant cell types. Here we have performed a comparative analysis of diverse models of high-grade serous ovarian cancer based on transcriptomic profiling of 22 cell line models, and intrabursal and intraperitoneal tumours from 12 models. Among cell lines, we identify distinct features in signalling activity, such as elevated inflammatory signalling in STOSE and OVE16 models, and MAPK/ERK signalling in ID8 and OVE4 models; metabolic features, such as predicted reduction in glycolysis associated with subsets of engineered ID8 subclones; and relevant functional properties, including differences in EMT activation, PD-L1 and MHC class I expression, and predicted chemosensitivity. Finally, we evaluate variability in properties of the tumour microenvironment among models. We anticipate that this work will serve as a valuable resource, providing new insight to help in the selection of models for specific experimental objectives.

cancer biology↗

bioRxiv2023

Subcortical correlates of consciousness with human single neuron recordings

Subcortical brain structures such as the subthalamic nucleus or the thalamus are involved in regulating motor and cognitive behavior. However, their contribution to perceptual consciousness is still unclear, due to the inherent difficulties of recording subcortical neuronal activity in humans. Here, we asked neurological patients undergoing surgery for deep brain stimulation to detect weak vibrotactile stimuli applied on their hand while recording single neuron activity from the tip of a microelectrode. We isolated putative single neurons in the subthalamic nucleus and thalamus. A significant proportion of neurons modulated their activity while participants were expecting a stimulus. We found that the firing rate of 23% of these neurons differed between detected and undetected stimuli. Our results provide direct neurophysiological evidence of the involvement of the subthalamic nucleus and the thalamus for the detection of vibrotactile stimuli, thereby calling for a less cortico-centric view of the neural correlates of consciousness.

neuroscience↗

bioRxiv2022

Prior information differentially affects discrimination decisions and subjective confidence reports

According to Bayesian models, both decisions and confidence are based on the same precision-weighted integration of prior expectations ("priors") and incoming information ("likelihoods"). This assumes that priors are integrated optimally and equally in decisions and confidence, which has not been tested. In two experiments, we quantitatively assessed how priors inform both decisions and confidence. With a gamified dual-decision task we controlled the strength of priors and likelihoods to create pairs of conditions that were matched in posterior information, but differed on whether the prior or likelihood was more informative. We found that priors were underweighted in discrimination decisions, but used to a greater extent in confidence about those decisions, and this was not due to differences in processing time. With a Bayesian model we quantified the weighting parameters for the prior at both levels, and confirmed that priors are more optimally used in explicit confidence, even when underused in decisions.

neuroscience↗

bioRxiv2022

Multinucleation resets human macrophages for specialized functions at the expense of mononuclear phagocyte identity

Macrophages undergo plasma membrane fusion and cell multinucleation to form multinucleated giant cells (MGCs) such as osteoclasts in bone, Langhans giant cells (LGCs) as part of granulomas or foreign-body giant cells (FBGCs) in reaction to exogenous material. While osteoclast multinucleation is a prerequisite for vertebrate bone homeostasis, the effector function resulting from LGC and FBGC multinucleation is less well-defined. More generally, how multinucleation per se contributes to functional specialization of mature mononuclear macrophages remains poorly understood in humans. Here, we integrated comparative transcriptomics with functional assays in purified mature mononuclear and multinucleated human osteoclasts, LGCs and FBGCs. Strikingly, in all three types of MGCs, multinucleation causes a pronounced down-regulation of mononuclear phagocyte identity. We show enhanced lysosome-mediated intracellular iron homeostasis promoting MGC formation. The transition from mononuclear to multinuclear state is accompanied by cell specialization specific to each polykaryon. Enhanced phagocytic and mitochondrial function associate with FBGCs and osteoclasts, respectively. Moreover, only B7-H3 (CD276)-expressing human LGCs can form granuloma-like clusters in vitro, suggesting that LGC multinucleation potentiates T cell activation. These findings demonstrate how cell-cell fusion and multinucleation reset human macrophage identity as part of an advanced maturation step that confers MGC-specific functionality.

cell biology↗

bioRxiv2022

Analysis of pre-symptomatic Drosophila models for ALS and SMA reveals convergent impact on functional protein complexes linked to neuro-muscular degeneration

Spinal Muscular Atrophy (SMA) and Amyotrophic Lateral Sclerosis (ALS) share phenotypic and molecular commonalities, including the fact that they can be caused by mutations in ubiquitous proteins involved in RNA metabolism, namely SMN, TDP-43 and FUS. Although this suggests the existence of common disease mechanisms, there is currently no model to explain the resulting motor neuron dysfunction. In this work we generated a parallel set of Drosophila models for adult-onset RNAi and tagged neuronal expression of the fly orthologues of the three human proteins, named Smn, TBPH and Caz, respectively. We profiled nuclear and cytoplasmic bound mRNAs using a RIP-seq approach and characterized the transcriptome of the RNAi models by RNA-seq. To unravel the mechanisms underlying the common functional impact of these proteins on neuronal cells, we devised a computational approach based on the construction of a tissue-specific library of protein functional modules, selected by an overall impact score measuring the estimated extent of perturbation caused by each gene knockdown. Transcriptome analysis revealed that the three proteins do not bind to the same RNA molecules and that only a limited set of functionally unrelated transcripts is commonly affected by their knock-down. However, our integrative approach revealed they exert a concerted effect on protein functional modules, acting through distinct targets. Most strikingly, functional annotation revealed that these modules are involved in critical cellular pathways for motor neurons, including neuromuscular junction function. Furthermore, selected modules were found to be significantly enriched in orthologues of human neuronal disease genes. The results presented here show that SMA and ALS disease-associated genes linked to RNA metabolism functionally converge on neuronal protein complexes, providing a new hypothesis to explain the common motor neuron phenotype. The functional modules identified represent promising biomarkers and therapeutic targets, namely given their alteration in asymptomatic settings.

neuroscience↗

bioRxiv2021

Optimal confidence for unaware visuomotor deviations

Numerous studies have shown that humans can successfully correct deviations to ongoing movements without being aware of them, suggesting limited conscious monitoring of visuomotor performance. Here, we ask whether such limited monitoring impairs the capacity to judiciously place confidence ratings to reflect decision accuracy (metacognitive sensitivity). To this end, we recorded functional magnetic resonance imaging data while thirty-one participants reported visuomotor cursor deviations and rated their confidence retrospectively. We show that participants use a summary statistic of the unfolding visual feedback (the maximum cursor error) to detect deviations but that this information alone is insufficient to explain detection performance. The same summary statistics is used by participants to optimally adjust their confidence ratings, even for unaware deviations. At the neural level, activity in the ventral striatum tracked high confidence, whereas a broad network including the anterior prefrontal cortex encoded cursor error but not confidence, shedding new light on a role of the anterior prefrontal cortex for action monitoring rather than confidence. Together, our results challenge the notion of limited action monitoring and uncover a new mechanism by which humans optimally monitor their movements as they unfold, even when unaware of ongoing deviations.

neuroscience↗

bioRxiv2021

LysM receptors in Coffea arabica: identification, characterization, and gene expression in response to Hemileia vastatrix

Pathogen-associated molecular patterns (PAMPs) are recognized by pattern recognition receptors (PRRs) localized on the host plant cell wall. These receptors activate a broad-spectrum and durable defense, which are desired characteristics for disease resistance in plant breeding programs. In this study, candidate sequences for PRRs with lysin motifs (LysM) were investigated in the Coffea arabica genome. For this, approaches based on the principle of sequence similarity, conservation of motifs and domains, phylogenetic analysis, and modulation of gene expression in response to Hemileia vastatrix were used. The candidate sequences for PRRs in C. arabica (Ca1-LYP, Ca2-LYP, Ca1-CERK1, Ca2-CERK1, Ca-LYK4, Ca1-LYK5 and Ca2-LYK5) showed high similarity with the reference PRRs used: Os-CEBiP, At-CERK1, At-LYK4 and At-LYK5. Moreover, the ectodomains of these sequences showed high identity or similarity with the reference sequences, indicating structural and functional conservation. The studied sequences are also phylogenetically related to the reference PRRs described in Arabidopsis, rice, and other plant species. All candidates for receptors had their expression induced after the inoculation with H. vastatrix, since the first time of sampling at 6 hours post-inoculation (hpi). At 24 hpi, there was a significant increase in expression, for most of the receptors evaluated, and at 48 hpi, a suppression. The results showed that the candidate sequences for PRRs in the C. arabica genome display high homology with fungal PRRs already described in the literature. Besides, they respond to pathogen inoculation and seem to be involved in the perception or signaling of fungal chitin, acting as receptors or coreceptors of this molecule. These findings represent an advance in the understanding of the basal immunity of this species.

plant biology↗

bioRxiv2021

Age-related pathological impairments in induced neurons derived from patients with idiopathic Parkinson's disease

Understanding the pathophysiology of Parkinsons disease has been hampered by the lack of models that recapitulate all the critical factors underlying its development. Here, we generated functional induced dopaminergic neurons (iDANs) that were directly reprogrammed from adult human dermal fibroblasts of patients with idiopathic Parkinsons disease to investigate diseaserelevant pathology. We show that iDANs derived from Parkinsons disease patients exhibit lower basal chaperone-mediated autophagy as compared to iDANs of healthy donors. Furthermore, stress-induced autophagy resulted in an accumulation of macroautophagic structures in induced neurons (iNs) derived from Parkinsons disease patients, independently of the specific neuronal subtype but dependent on the age of the donor. Finally, we found that these impairments in patient-derived iNs lead to an accumulation of phosphorylated alpha-synuclein, a hallmark of Parkinsons disease pathology. Taken together, our results demonstrate that direct neural reprogramming provides a patient-specific model to study aged neuronal features relevant to idiopathic Parkinsons disease.

neuroscience↗

bioRxiv2021

The Autophagy Receptor TAX1BP1 (T6BP) is a novel player in antigen presentation by MHC-II molecules.

CD4+ T lymphocytes play a major role in the establishment and maintenance of immunity. They are activated by antigenic peptides derived from extracellular or newly synthesized (endogenous) proteins presented on the surface of antigen presenting cells (APCs) by the MHC-II molecules. The pathways leading to endogenous MHC-II presentation remain poorly characterized. We demonstrate here that the autophagy receptor, T6BP, influences both autophagy-dependent and -independent endogenous presentation of HIV- and HCMV-derived peptides. By studying the immunopeptidome of MHC-II molecules, we show that T6BP affects both the quantity and quality of peptides presented. T6BP silencing induces the mislocalization of the MHC-II-loading compartments and a rapid degradation of the invariant chain (CD74) without altering the expression and internalization kinetics of MHC-II molecules. We determined the interactome of T6BP, identified calnexin as a T6BP partner and show that CANX cytosolic tail is required for this interaction. Remarkably, calnexin silencing replicates the functional consequences of T6BP silencing: decreased CD4+ T cell activation and exacerbated CD74 degradation. Altogether, we unravel T6BP as a key player of the MHC-II-restricted endogenous presentation pathway and we propose one potential mechanism of action.

immunology↗

bioRxiv2021

CRISPR-Targeted CAR Gene Insertion Using Cas9/RNP and AAV6 Enhances Anti-AML Activity of Primary NK Cells

Human peripheral blood natural killer (NK) cells have intense antitumor activity and have been used successfully in several clinical trials. Modifying NK cells with a chimeric antigen receptor (CAR) can improve their targeting and increase specificity. Recently, we described an efficient method for gene targeting in NK cells using Cas9/ribonucleoprotein (RNP) complexes. Here we combined this approach with single-stranded (ss) or self-complementary (sc) Adeno-associated virus (AAV)-mediated gene delivery for gene insertion into a safe-harbor locus using a wide variety of homology arms for homology repair (HR) and non-homologous directed CRISPR-assisted insertion tagging (CRISPaint) approaches. For proof-of-concept, we generated mCherry-expressing primary NK cells and determined that sc vectors with 300bp homology arms had optimal transduction efficiency. Then, we generated CD33-targeting CAR NK cells with differing transmembrane and signaling domains (CD4/4-1BB+CD3{zeta} and NKG2D/2B4+CD3{zeta}) and expanded them on CSTX002 feeder cells. Expansion kinetics were unaltered and the expanded NK cells maintained high CAR expression (mean 68% CAR+). The CD33-CAR-NK cells showed increased activation markers and enhanced antileukemic activity with improved killing kinetics against CD33-positive acute myeloid leukemia (AML) cell lines and primary samples. Using targeted sequencing we demonstrated the accuracy of CAR gene insertion in human primary NK cells genome. Site-directed insertion using RNP and scAAV6 is an efficient method for stable genetic transfer into primary NK cells that has broad potential for fundamental discovery and therapeutic applications.

immunology↗

bioRxiv2020

Increased functional connectivity of the intraparietal sulcus underlies the attenuation of numerosity estimations for self-generated words

Previous studies have shown that self-generated stimuli in auditory, visual, and somatosensory domains are attenuated, producing decreased behavioral and neural responses compared to the same stimuli that are externally generated. Yet, whether such attenuation also occurs for higher-level cognitive functions beyond sensorimotor processing remains unknown. In this study, we assessed whether cognitive functions such as numerosity estimations are subject to attenuation. We designed a task allowing the controlled comparison of numerosity estimations for self (active condition) and externally (passive condition) generated words. Our behavioral results showed a larger underestimation of self-compared to externally-generated words, suggesting that numerosity estimations for self-generated words are attenuated. Moreover, the linear relationship between the reported and actual number of words was stronger for self-generated words, although the ability to track errors about numerosity estimations was similar across conditions. Neuroimaging results revealed that numerosity underestimation involved increased functional connectivity between the right intraparietal sulcus and an extended network (bilateral supplementary motor area, left inferior parietal lobule and left superior temporal gyrus) when estimating the number of self vs. externally generated words. We interpret our results in light of two models of attenuation and discuss their perceptual versus cognitive origins.

neuroscience↗

bioRxiv2020

Optimal protocols for sequence-based characterization of the human vaginal microbiome

The vaginal microbiome has been connected to a wide range of health outcomes. This has led to a thriving research environment, but also to the use of conflicting methodologies to study its microbial composition. Here we systematically assess best practices for the sequencing-based characterization of the human vaginal microbiome. As far as 16S rRNA gene sequencing is concerned, the V1-V3 region has the best theoretical properties, but limitations of current sequencing technologies mean that the V3-V4 region performs equally well. Both of these approaches present very good agreement with qPCR quantification of key taxa, provided an appropriate bioinformatic pipeline is used. Shotgun metagenomic sequencing presents an interesting alternative to 16S amplification and sequencing, but it is not without its challenges. We have assessed different tools for the removal of host reads and the taxonomic annotation of metagenomic reads, including a new, easy-to-build and - use, reference database of vaginal taxa. This strategy performed as well as the best performing previously published strategies. Despite the many advantages of shotgun sequencing none of the shotgun approaches assessed here had as good agreement with the qPCR data as 16S rRNA gene sequencing. ImportanceThe vaginal microbiome has been connected to a wide range of health outcomes, from susceptibility to sexually transmitted infections to gynecological cancers and pregnancy outcomes. This has led to a thriving research environment, but also to conflicting available methodologies, including many studies that do not report their molecular biological and bioinformatic methods in sufficient detail for them to be considered reproducible. This can lead to conflicting messages and delay progress from descriptive to intervention studies. By systematically assessing best practices for the characterization of the human vaginal microbiome, this study will enable past studies to be assessed more critically and assist future studies in the selection of appropriate methods for their specific research questions.

molecular biology↗

bioRxiv2020

A trans-eQTL network regulates osteoclast multinucleation and bone mass

Functional characterisation of cell-type specific regulatory networks is key to establish a causal link between genetic variation and phenotype. The osteoclast offers a unique model for interrogating the contribution of co-regulated genes to in vivo phenotype as its multinucleation and resorption activities determine quantifiable skeletal traits. Here we took advantage of a trans-regulated gene network (MMnet, macrophage multinucleation network) which we found to be significantly enriched for GWAS variants associated with bone-related phenotypes. We found that the network hub gene Bcat1 and seven other co-regulated MMnet genes out of 13, regulate bone function. Specifically, global (Pik3cb-/-, Atp8b2+/-, Igsf8-/-, Eml1-/-, Appl2-/-, Deptor-/-) and myeloid-specific Slc40a1{Delta}LysMCre knockout mice displayed abnormal bone phenotypes. We report antagonizing effects of MMnet genes on bone mass in mice and osteoclast multinucleation/resorption in humans with strong correlation between the two. These results identify MMnet as a functionally conserved network that regulates osteoclast fusion and bone mass. Impact statementWe took advantage of the osteoclast whose multinucleation properties correlate with bone mass. We show that a trans-regulated gene network (MMnet) controls skeletal homeostasis through osteoclast multinucleation and function.

cell biology↗

bioRxiv2018

Disentangling the origins of confidence in speeded perceptual judgments through multimodal imaging

The human capacity to compute the likelihood that a decision is correct - known as metacognition - has proven difficult to study in isolation as it usually co-occurs with decision-making. Here, we isolated post-decisional from decisional contributions to metacognition by combining a novel paradigm with multimodal imaging. Healthy volunteers reported their confidence in the accuracy of decisions they made or decisions they observed. We found better metacognitive performance for committed vs. observed decisions, indicating that committing to a decision informs confidence. Relying on concurrent electroencephalography and hemodynamic recordings, we found a common correlate of confidence following committed and observed decisions in the inferior frontal gyrus, and a dissociation in the anterior prefrontal cortex and anterior insula. We discuss these results in light of decisional and post-decisional accounts of confidence, and propose a generative model of confidence in which metacognitive performance naturally improves when evidence accumulation is constrained upon committing a decision.

neuroscience↗