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Li, Y.

Publications and source records attributed to Li, Y..

At least 199 records · Page 11Linked to original sources

TLR7 Signaling Regulates Embryonic Hematopoietic Stem Cell Development by Sensing microRNA-146a in Vertebrates

The specification of hematopoietic stem cells (HSCs) is tightly regulated by multiple transcription factors and signaling pathways. Inflammatory signaling is pivotal for embryonic HSC development, but the mechanisms that activate it in vivo remain poorly understood. Here, we show that Toll-like receptor 7 (TLR7) is essential for the emergence of embryonic HSC in both zebrafish and mouse embryos. TLR7 deficiency reduces HSC numbers but not primitive or definitive progenitors. Conversely, the TLR7 agonist R848 enhances embryonic HSC development. Mechanistically, TLR7 signaling acts through interferon regulatory factor 5 (IRF5) to induce the expression of inflammatory cytokines, which subsequently activate Notch signaling to promote HSC emergence through a non-cell-autonomous mechanism. Notably, we identify microRNA-146a (miR-146a) as a potential endogenous activator of TLR7, inducing inflammatory signaling and promoting HSC development. Pharmacological treatment with miR-146a significantly increases HSC numbers in zebrafish embryos. Together, our findings reveal a crucial role for miR-146a-TLR7-IRF5 signaling axis in HSC emergence, providing insights into the endogenous factors that drive tonic inflammatory signaling during normal hematopoiesis and suggesting the translational potential of TLR7 agonists and miR-146a for stem-cell-based therapeutics. Significance StatementThe embryonic origin of hematopoietic stem cells (HSCs) requires inflammatory signals, but the endogenous factor that triggers this process remains elusive. We identify microRNA-146a (miR-146a) as a natural activator of Toll-like Receptor 7 (TLR7) signaling, which is essential for HSC emergence. This miR-146a-TLR7 axis functions through IRF5 and inflammatory cytokines to activate the Notch signaling, specifically promoting embryonic HSC development. Our work addresses the critical question of endogenous ligands that mediate tonic inflammatory signaling in normal hematopoiesis, uncovers novel crosstalk between miRNAs and innate immunity in HSC specification, and identifies promising candidates for stem cell-based therapeutics.

developmental biology↗

Analysis of isoform complexity in pan-transcriptome graphs with atroplex

MotivationAlternative splicing of precursor mRNA lets a single gene encode multiple isoforms by joining exons in different combinations. Long-read sequencing resolves this isoform diversity across tissues, cohorts, and conditions. However, the resulting pan-transcriptomes are structurally complex, and their analysis requires repeatedly searching the full catalogue, which is impractical without a queryable index. As splicing patterns differ across conditions, a structure is needed that captures the connectivity between exons, not just their coordinates, so isoforms can be compared by structure across cohorts. ResultsWe present atroplex, a framework that indexes pan-transcriptome annotations and transcript isoforms in a combined spatial index and graph overlay, capturing both exon coordinates and splice connectivity. atroplex classifies query transcripts against the index, tracks per-sample isoform presence, and enables crosscohort isoform comparison. We indexed 21,005 samples spanning multiple reference resources into a single queryable structure, yielding a comprehensive map of isoform complexity that supports improved transcript discovery and structural comparison across cohorts.

bioinformatics↗

Selection of potent biologic antagonists of the cannabinoid GPCR CB2R from a constrained peptide library

Dysregulated gut homing of leukocytes drives chronic inflammation in Crohns disease (CD). We employed phage display selection campaigns with libraries of stabilized, constrained peptides against endogenous conformation states of the cannabinoid receptor CB2R on human T cells, to discover novel receptor antagonists with potential to inhibit gut homing. Cluster and frequency analysis of 50,000 enriched sequences resulted in expression and functional characterisation of 10 protein candidates using assays of glucose uptake, ERK phosphorylation (pERK) and {beta}-arrestin recruitment. Each candidate antagonised CB2R activity with recorded IC50 values of between 5-10 nM. Cannabinoid receptor nanodisc binding experiments and FSEC confirmed CB2R selectivity. SLKC_09 with an IC50 of 5.4 nM, was studied in a mouse model of chronic ileitis where it significantly inhibited gut homing of CD4+ & CD8+ naive, effector and memory cell types. Our findings highlight an alternative route to therapeutic inhibition of leukocyte trafficking in CD with a biologic inhibitor of CB2R.

immunology↗

CryoGO enables high-resolution structural profiling of endogenous cellular macromolecules

Resolving macromolecular structures within their native cellular environment is essential for connecting molecular architecture to physiological function, yet the field lacks accessible, high-throughput methods for generating suitable specimens from cells. Here, we introduce cryoGO (on-Grid Opening cryo-electron microscopy), a simple, rapid, and scalable strategy that mechanically opens cells directly on EM grids to produce cell-derived specimens for high-resolution single-particle cryo-EM. This approach enables near-atomic structure determination of diverse endogenous macromolecular assemblies spanning a broad molecular-weight range. We show that cryoGO captures the rich ribosomal conformational and compositional landscape while preserving physiological state distributions and aspects of spatial heterogeneity originating from cells. Furthermore, this rapid workflow enables time-resolved structural profiling, capturing both long-term cellular adaptation and acute remodeling on timescales of seconds. Compatible with standard cryo-EM infrastructure and diverse biological samples, while requiring only small numbers of cells, cryoGO lowers the technical barrier to high-resolution native structural biology.

biophysics↗

Comprehensive transcriptome data of melittin- and un-treated murine hepatoma Hepa 1-6 cells

Melittin, the principal bioactive peptide of bee venom, exerts potent antitumor activity against hepatocellular carcinoma (HCC). However, the comprehensive transcriptomic alterations it elicits in hepatoma cells remain poorly characterized. Here, we present an integrated transcriptome dataset from melittin- and un-treated murine Hepa 1-6 hepatoma cells, encompassing messenger RNA (mRNA) and microRNA (miRNA) expression profiles. Cells were exposed to 4 g/mL melittin in serum-free DMEM for 20 min, and total RNA was subjected to ribosomal RNA-depleted strand-specific RNA sequencing on an Illumina NovaSeq6000 platform (paired-end 150 bp) and small RNA sequencing on an Illumina HiSeq2500 platform (single-end 50 bp). Raw data were processed using Cutadapt to remove adapters and low-quality reads, yielding clean datasets with Q20 [≥] 99.85%, Q30 [≥] 98.48%, and valid data ratios exceeding 85%. All raw and processed sequencing data are publicly available. This transcriptomic resource provides a valuable resource and basis for elucidating the regulatory networks underlying melittin-induced anti-hepatoma effects. DatasetThe dataset can be accessed through the National Genomics Data Center, China National Center website by searching with the BioProject accession number PRJCA065485 Reviewers may use this link for anonymous access during the review process. Direct URL to data: Genome Sequence Archive-CNCB-NGDC. Dataset LicenseCC BY 4.0

Cancer Biology↗

RNArefine: AI-guided Atomic-Level Refinement of RNA Structures

Considerable progress has been made in AI-driven RNA structure prediction, but the resulting models often lack complete atomic details or suffer from severe stereochemical distortions and incorrect local interactions. We present RNArefine, an AI-guided hierarchical framework for atomic-level RNA structure refinement. RNArefine first predicts base-pairing and base-stacking interactions using geometric attention networks and then integrates the interactions with physics-based force fields to guide a two-step refinement strategy consisting of Monte Carlo conformational sampling followed by L-BFGS energy optimization. Large-scale benchmark experiments on both sequence-based prediction models and cryo-EM-derived structures demonstrated that RNArefine consistently improves stereochemical quality, interaction fidelity and physically penalized structural accuracy while preserving global topology. When applied to blind CASP16 RNA prediction models, RNArefine improved ranking scores for 28 of the top 30 groups. These results establish RNArefine as a robust open-source framework for transforming raw RNA folds into physically realistic atomic models for downstream structural and therapeutic applications.

bioengineering↗

Notch Signaling Reprograms Glial Lipid Metabolism to Promote Hypoxia Resistance

Hypoxia poses a major threat to the developing nervous system, where high metabolic demand is required to support brain growth, glial and neuronal maturation, and function. Although glial cells are essential for maintaining neural homeostasis under stress, how specific glial subtypes remodel metabolism to promote hypoxia tolerance remains poorly understood. Here, we identify a Notch-dependent lipid metabolic program in excitatory amino acid transporter 1 (Eaat1)-positive glia that supports hypoxia adaptation in the developing Drosophila larval brain. Using stimulated Raman scattering (SRS) microscopy combined with deuterium-labeled metabolic probes, we visualized substrate-specific metabolic activity in vivo at subcellular resolution. In control, non-adapted flies, we found that acute hypoxia markedly increased de novo lipogenesis in Eaat1-positive glia. In flies adapted to chronic hypoxia, Eaat1-positive glia exhibited a pre-programmed metabolic shift, characterized by reduced glucose-derived lipogenesis and enhanced acetate-derived lipid synthesis. Constitutive activation of Notch signaling in Eaat1-positive glia was sufficient to phenocopy this acetate-favored lipogenic state, suggesting that Notch promotes metabolic plasticity under oxygen-limited conditions. To define the transcriptional programs associated with this response, we performed single-nucleus RNA sequencing (snRNA-seq) of the developing Drosophila central nervous system and mapped Eaat-1expressing cell populations across hypoxia and Notch activation. Notch activation reshaped hypoxia-associated transcriptional responses and counteracted metabolic suppression caused by low oxygen. Together, our findings identify Eaat1-positiveglia as a metabolically adaptive glial population and reveal a conserved Notch-regulated mechanism that rewires lipid metabolism to support hypoxia tolerance in the developing brain. These results provide insight into glial metabolic strategies that may be relevant to hypoxia-associated neurological conditions, including neonatal hypoxic-ischemic brain injury and ischemic stroke.

Cell Biology↗

Pep2Mol: 3D Molecule Generation Targeting Protein-Protein Interfaces with Diffusion Models

Protein-protein interactions (PPIs) are central to biological processes. Designing small molecules that modulate dysregulated PPIs holds strong promise for targeting undruggable proteins. However, existing structure-based drug design approaches focus on well-defined small-molecule binding pockets and struggle to generalize to large, shallow, and chemically complex PPI interfaces. Here, we introduce Pep2Mol, a diffusion-based generative model for 3D molecule design that targets orthosteric PPI sites by explicitly incorporating binding peptides or proteins as structural guidance, moving beyond conventional pocket-conditioned generation. To enable model development and benchmarking, we curate a large-scale, high-quality dataset of 10,956 experimentally resolved protein complex structure pairs, each pairing an orthosteric competitive ligand with a protein binder at overlapping receptor interfaces. Pep2Mol integrates two SE(3)-equivariant graph neural networks that encode protein-ligand and protein-peptide interactions respectively, and fuses these representations via attention-based conditioning to jointly guide the diffusion trajectory. Extensive evaluations demonstrate that Pep2Mol generates chemically valid ligands with state-of-the-art binding affinities, providing a strong foundation for small-molecule inhibitor design against challenging PPI interfaces.

bioinformatics↗

Peri-Locus Coeruleus Controls Endothelial Cell Heterogeneity in Enriched Environments via Region-Specific Norepinephrine Signaling

The brain acts as a central integrator that enables organisms to interpret environmental stimuli and coordinate adaptive responses across the body. While enriched environments are known to enhance neural plasticity and cognitive function, their impact on peripheral organ systems remains less understood. Here, we show that enriched environmental conditions activate a peri-locus coeruleus (peri-LC) neuronal ensemble that preserves CD31hiEMCNhi type H endothelium, a specialized bone-associated endothelial subtype, against age-associated decline, thereby enhancing femoral bone density. Chemogenetic activation and ablation experiments further revealed that this peri-LC ensemble is functionally distinct from other sympathetic regulatory brain regions in its control of bone endothelial heterogeneity and skeletal mass. Three-dimensional bone clearing and spatial analyses showed that CD31hiEMCNhi endothelium is closely associated with sympathetic nerve terminals. The peri-LC mediates this process through sympathetic signaling and {beta}2-adrenergic receptors on bone vascular endothelial cells. In vivo imaging further demonstrated that norepinephrine release is spatially restricted, with sprouting endothelial cells near the growth plate exhibiting the highest sensitivity. Together, these findings reveal a refined brain-periphery regulatory logic in which distinct sympathetic brain circuits engage spatially restricted norepinephrine signaling to coordinate organ-specific vascular and skeletal adaptations.

neuroscience↗

Depleting prion protein using splice-switching small molecules

Prion diseases are fatal neurodegenerative disorders driven by prion protein (PrP) misfolding, and lowering cellular PrP represents a promising therapeutic strategy. Here we report a small-molecule approach that reduces PrP by modulating pre-mRNA splicing of the PRNP gene. Through chemical modification of the clinically approved splicing modulator risdiplam, we generated CP3, the first class of compounds that selectively activate a cryptic exon in PRNP and routes its mRNA product for degradation, reducing PrP by [~]70% in cells. We demonstrate that CP3 activity critically depends on alternative splicing factor Luc7L, revealing a novel requirement for alternative splicing factors in small molecule splicing modulation. Strikingly, co-administration of CP3 with a Luc7L activator PTC258 significantly lowers PrP levels in the brains of transgenic mice. These results establish splicing modulation as a powerful strategy for PrP reduction and highlight the potential of small-molecule cooperativity for therapeutic RNA targeting.

biochemistry↗

Characterization of acetate catabolism in Chlamydomonas reinhardtii reveals distinct roles for ACS1 and ACK2 in regulating cell growth and carbon storage

Acetate metabolism drives mixotrophic and heterotrophic growth in some microalgae. Acetyl-CoA synthetase (ACS) and acetate kinase (ACK) are often considered the main enzymes involved in acetate catabolism in microalgae; however, their contributions to metabolic flux and carbon allocation are not fully understood. In this study, the functions of cytosolic ACS1 and mitochondrial ACK2 were characterized using two knockout mutants of the model microalga Chlamydomonas reinhardtii. The acs1 mutant exhibited a growth-oriented phenotype, characterized by 29.8% faster cell growth at 96 h and up to a 15.5% higher acetate depletion rate, yet showed a 38.3% lower triacylglycerol (TAG) content at 48 h under heterotrophic conditions. By contrast, the ack2 mutant exhibited an altered carbon-allocation phenotype under heterotrophic conditions. Despite an up to 32.4% lower respiratory oxygen consumption rate and a 27.7% reduction in cell density, ack2 exhibited a 39.3% higher biomass concentration and a 90.4% greater dry weight per cell than the wild type at 96 h. Biochemical analysis revealed that ack2 accumulated 23.3% more carbohydrate than the wild type at 120 h under heterotrophic conditions, whereas its TAG level remained comparable to that of the wild type. These findings suggest that, under heterotrophic conditions, the loss of cytosolic ACS1 facilitates cell growth and division at the expense of TAG biosynthesis, whereas the loss of mitochondrial ACK2 regulates growth by affecting carbon flux toward biomass and carbohydrate accumulation. This work provides insight into acetate catabolism in C. reinhardtii and suggests targets for engineering microalgae for production of biomass and bioproducts.

Molecular Biology↗

Dysfunction of the colliculus-pulvinar pathway in children with developmental dyslexia

While evidence suggests magnocellular deficits in the geniculostriate pathway in adults with dyslexia, neural deficits in the subcortical pathways during childhood remain unclear. Here, we used high-resolution fMRI to investigate subcortical abnormalities in Chinese children with developmental dyslexia. Fast achromatic motion stimuli and slowly drifting chromatic gratings were used to assess magnocellular (M) and parvocellular (P) functions, respectively. Relative to controls, children with dyslexia showed a selective reduction in responses to the M stimulus in the ventromedial pulvinar (vmPul) and the superficial layers of the superior colliculus (SCs), along with significantly reduced SCs-vmPul connectivity. Importantly, while vmPul responses to the M stimulus were positively associated with reading skills in healthy controls, this correlation was absent in children with dyslexia. Unlike previous findings in adults, the lateral geniculate nucleus (LGN) exhibited a non-selective reduction in responses to both stimuli, no volume reduction, and no correlation with reading ability. These findings demonstrate a selective deficit to achromatic motion processing in the colliculus-pulvinar pathway in children with dyslexia, which contributes to their reading difficulties. This early subcortical disruption differs from, and precedes, the neural deficits previously reported in the adult LGN, offering new insight into the developmental trajectory of dyslexia.

neuroscience↗

“Mapping of Gonadal Development in Cryptorchidism: UTF-1 and Germ Cell Dysgenesis”

Study questionHow does cryptorchidism affect germ cell development and UTF-1-mediated pluripotency potential at the time of orchiopexy? Summary answerCryptorchidism was associated with the following germ cell abnormalities: germ cell clustering with many cords/tubules lacking germ cells and reduced UTF-1 expression, suggesting limited germ cell differentiation into spermatogonia What is known alreadyCryptorchidism, affecting 1.6-9% of male newborns, is known to increase the risk of infertility and testicular cancer due to abnormal germ cell development. Germ cells and pluripotent stem cell gene, UTF-1, play critical roles in spermatogonia differentiation, self-renewal, and spermatogenesis. No prior study has evaluated the testicular development by immunohistochemically mapping of these cell populations, Study design, size, durationA cross-sectional study of 31 postnatal cryptorchid testis and 5 age-matched scrotal testicular biopsies obtained from UCSFs pathology department performed between 1993-2023. Participants/materials, setting, methodsSpecimens were grouped by age at surgery (6-18 months, 19 months-7 years, 8-12 years, and [≥]13 years) and testis location (palpable vs. non-palpable). Scrotal prepubertal testis biopsies were sourced through the Pedi-LIFE program, a fertility preservation research biobank, with at least one control per age group. Immunohistochemistry was performed to stain specimens for germ cell (DDX4, OCT4, TSPY), pluripotent cell marker (UTF-1), as well as other key testis cell markers (A-actin, AR, P450, Sox-9), with staining graded based on control expression levels. The number of germ cells per seminiferous tubule was quantified and compared across anatomical locations using appropriate statistical analyses. Main results and the role of chanceThis study included 36 specimens, comprising 31 cryptorchid testes (86%) and 5 scrotal control testes (16%). The cryptorchid group exhibited testicular dysgenesis and reduced germ cell expression, correlated with increased age and testis location. Qualitative assessment revealed reduced germ cell expression across all ages in cryptorchid testes. The number of germ cells per tubule was markedly reduced in cryptorchid compared with scrotal testes after 19 months of age for DDX4, TSPY, and UTF-1. Germ cell clusters were identified in 15 out of 31 cryptorchid specimens (48%) stained for DDX4 and TSPY. UTF-1 expression was lower in cryptorchid testes across all age groups. No significant differences were noted in other testicular cell markers. Large scale dataNA Limitations, reasons for cautionFirst, the power and generalizability of the study are limited by the availability of specimens within each age group, particularly for scrotal testes, as biopsies of these tissues are not routinely performed. Second, a cross-sectional study design limits a longitudinal comparison to evaluate changes in marker expression, delayed maturation, or irreversible germ cell loss. Third, immunohistochemistry data is semi-quantitative, and protein detection is affected by antibody sensitivity and tissue preservation and influenced by antibody sensitivity. Lastly, scrotal testis used as controls were obtained from cryopreserved tissue from patients with other unrelated pathology, which may influence histological profiles. Wider implications of the findingsCollectively, our findings support a model in which cryptorchidism involves both germ cell depletion and disrupted SSC lineage formation, with UTF-1 downregulation and germ cell clustering as early signatures of testicular dysgenesis. These features may help identify high-risk patients for worsening gonadal dysgenesis and infertility and can provide a rationale for earlier orchiopexy or SSC-preserving strategies. Study funding/competing interest(s)The authors declare no conflicts of interest and received no funding for this study. Data Availability StatementThe data underlying this article cannot be shared publicly due to ethical and legal restrictions related to the use of human tissue specimens, which may compromise donor privacy and confidentiality. Data are available from the corresponding author upon reasonable request and subject to institutional and ethical approvals.

Developmental Biology↗

Generative Modeling of Mouse Embryogenesis for Fate and Disease Prediction

Embryonic development is orchestrated by complex gene regulatory networks, and learning regulatory dynamics from developmental data could allow us to understand, predict, and ultimately engineer cell fates. Here we introduce Navigo (https://github.com/aristoteleo/Navigo-release), a biologically grounded generative modeling framework that learns a developmental vector field by integrating flow matching at the population level with RNA kinetics modeling at the molecular level. Navigo accurately maps developmental trajectories across lineages on a mouse embryogenesis scRNA-seq atlas spanning 43 time points and comprising 12.4 million cells. Applied to cardiac development, Navigo enables disease modeling by mechanistically resolving regulatory networks that distinguish congenital heart disease subtypes. Navigo also predicts perturbation effects in a zero-shot manner, as validated on independent in vivo data from six knockout genotypes without perturbation-specific training, uncovering lineage-specific gene-compensation mechanisms. Moreover, Navigo guides rational cell-fate engineering, exemplified by fibroblast reprogramming analyses, including identifying pro-fibrotic barriers to cardiac fates and evaluating hundreds of pairwise transcription factor combinations for neuronal fate, each consisting of one bHLH factor and one POU factor. Overall, Navigo provides a generalizable AI platform for perturbation-effect prediction, disease modeling, and rational cell-fate engineering, advancing toward AI-based virtual embryos for developmental biology and regenerative medicine.

bioinformatics↗

Prenatal e-cigarette exposure induces region- and cell type-specific metabolic and developmental reprogramming

Prenatal e-cigarette exposure (PeCE) is increasingly prevalent and has been associated with adverse neurodevelopmental outcomes, yet how maternal vaping perturbs early brain development remains poorly understood. We integrated spatial transcriptomics, snRNA-seq and lipidomics to define neonatal rat brain responses to PeCE in rats at regional and cellular resolution. PeCE induced pronounced spatial heterogeneity in vulnerability, with the striatum exhibiting the strongest developmental transcriptional disruption. PeCE disrupts lipid metabolic homeostasis and induced molecular signatures suggestive of enhance Ca2+ signaling, dopaminergic responsiveness and region-specific synaptic stress programs. In the striatum, PeCE induced transcriptional programs consistent with altered lipid utilization, silent synapse-like molecular features, suppressed dendritic spine development and delayed D1-medium spiny neuron maturation. PeCE-sensitive genes were enriched in human autism spectrum disorders and neurodevelopment risk loci. Together, these findings identify disrupted metabolic and developmental reprogramming as a central feature of neonatal brain vulnerability to maternal vaping and provide a mechanistic framework linking PeCE to neurodevelopmental disease risk.

neuroscience↗

Focal radiotherapy improves CAR T cell therapy targeting prostate cancer

Chimeric antigen receptor (CAR) T cell therapy has limited efficacy against solid tumors such as prostate cancer due to the immunosuppressive tumor microenvironment (TME). Combining CAR T cells with existing therapies that remodel the TME and promote endogenous immune responses, such as radiation therapy and chemotherapies, may strengthen antitumor responses. Here, we assessed the potency of combining focal radiotherapy (RT), cyclophosphamide (Cy) preconditioning, and prostate stem cell antigen (PSCA)-CAR T cells against syngeneic prostate cancer models. Focal RT alone increased T cell and dendritic cell infiltration and activation in the irradiated tumor. Furthermore, the combination of all three therapies was critical for enhanced antitumor responses and survival across multiple subcutaneous, bone-metastatic, and multifocal disease models. This combination, in the irradiated TME and tumor-draining lymph nodes (tdLN), led to greater antigen presentation by myeloid cells and endogenous T cell activation and cytotoxicity. Our study demonstrates the potency of combining focal RT with PSCA-CAR T cells, significantly improving therapeutic responses in the irradiated tumor and contributing to a more robust systemic immune response against metastatic burden in prostate cancer.

Cancer Biology↗

Post-infection immune response in adults with COVID-19 with and without nirmatrelvir-ritonavir treatment and virologic rebound

BackgroundNirmatrelvir-ritonavir (N-R) reduces morbidity and mortality from COVID-19 in high-risk individuals; however, N-R use has been associated with risk of SARS-CoV-2 virologic rebound. The mechanisms contributing to virologic rebound after N-R treatment are currently unknown. One plausible mechanism is that antiviral treatment may alter the development of immune responses to SARS-CoV-2 infection, thereby contributing to rebound after cessation of therapy. MethodsWe profiled immune responses in a case-ascertained, longitudinal, prospective cohort of ambulatory individuals with COVID-19. Participants were grouped according to whether virological rebound occurred and whether they had received N-R treatment. We assessed antibody, T-cell, and innate responses. ResultsWe observed no differences in the binding or neutralizing antibody, T-cell, and innate immune responses between participants with virologic rebound compared to participants without virologic rebound. N-R use was associated with slightly weaker antibody responses overall, even after adjustment for immunosuppression. ConclusionVirologic rebound after N-R treatment is likely driven by non-immune mechanisms. FundingThe project was supported by the National Institutes of Health (R01 AI 138801) and the Massachusetts Consortium on Pathogen Readiness. Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the NIH.

immunology↗

Seeing the world in a grain of sand: Fine global and local representations in foveal and parafoveal vision

Foveal vision enables primates to perceive small objects with remarkable precision by resolving both fine-global form and fine-local detail. Yet current coarse-to-fine and local-to-global frameworks, derived largely from parafoveal recordings and large-object representations, posit that V1 encodes local detail whereas IT represents global form, leaving the neuronal basis of foveal object representation unresolved. Here we show that fine-global form and fine-local detail are encoded parallelly as early as V1 and preserved across V2, V4 and IT at both foveal (1{degrees}-2{degrees}) and parafoveal (2{degrees}-6{degrees}) retinal eccentricities. Coarse-global features dominate parafoveal vision and higher cortical areas. Response latencies revealed a rapid processing sequence, with 2-6 ms separating coarse-global, fine-local, and fine-global processing within parafoveal V1, V2 and V4. These findings establish a cortical neuronal framework to resolve fine-global form of small objects in foveal vision along primate ventral visual stream, supporting fine-scale perception during reading and fine object recognition. Highlights O_LIFoveal two-photon imaging across V1, V2, V4, and IT C_LIO_LIGlobal and local processing examined across eccentricity C_LIO_LIFine and coarse global representations emerge as early as V1 C_LIO_LIFine global and local representations are preserved from V1 up to IT C_LIO_LITightly timed coarse-to-fine-to-fine processing within each cortex C_LIO_LIFast coarse-global dominates parafoveal and higher cortical areas C_LI

neuroscience↗