Biology subjects

Chang, Y.

Publications and source records attributed to Chang, Y..

At least 37 records · Page 2Linked to original sources

bioRxiv2026

Single-Cell and Spatial Methods for Multimodal Functional Glycan Profiling in Tissues

Glycans regulate multiple physiological processes, including immune recognition and cancer progression. In disease, altered glycan landscapes are interpreted by human lectins. Functional glycan-lectin interactions are difficult to profile because glycans are not genome-encoded and their changes are poorly captured by existing multimodal methods. We present two platforms, single-cell outlining and transcriptome sequencing (scGOAT-seq) and GlycoScope, which use human lectins to enable functional glycan accessibility into single-cell and spatial multiomic measurements. ScGOAT-seq quantifies lectin-accessible glycan states with gene expression, while GlycoScope enables multiplexed in situ co-detection of glycans and proteins in tissues. Applying these approaches to immune cells, we identify stimulus-specific glycan remodeling and show that distinct Siglec-ligand-defined programs stratify immune activation states not captured by traditional methods; in follicular lymphoma, GlycoScope, resolves spatial glycan programs associated with malignant B cells and localized immune microenvironments. The presented methods provide a general framework for integrating functional glycan accessibility into single-cell and spatial multiomics.

molecular biology↗

bioRxiv2026

Downregulation of Satb1 is required to prevent autoimmunity by maintaining Tfh homeostasis

T follicular helper (Tfh) cells are a specialized subset of CD4 T cells that localize to germinal centers (GC), where they provide critical help to B cells through the delivery of IL-21 and other cytokines. Here, we demonstrate that the tight control of the chromatin remodeler Special AT-rich sequence-binding protein 1 (Satb1) is key for this process, as overexpression of Satb1 drives lymphoproliferation and expansion of the T cell and B cell compartments in secondary lymphoid organs. Specifically, Satb1 overexpression induces a pronounced shift towards Tfh cell differentiation and increased GC formation accompanied by an increase in non-classed switched GC B cells and auto-antibody secretion. These findings highlight the importance of the precise regulation of Satb1 in fine-tuning CD4 T cells and B cells responses and suggest a potential role for dysregulation of Satb1 in the pathogenesis of autoimmune disease such as systemic lupus erythematodes (SLE).

immunology↗

bioRxiv2026

Geometric Fragility in Alzheimer's Disease: Probing the Loss of Hippocampal Hierarchical Abstraction via Contrastive Point Cloud Modeling

While human spatial cognition relies on hierarchical abstraction to integrate local features, Alzheimers disease (AD) pathology is often reduced to local volumetric atrophy. We propose geometric fragility as a distinct failure of global topological integrity within the hippocampus rather than a mere accumulation of local errors. Using a texture-invariant point cloud framework, we contrasted local feature aggregation with global hierarchical attention as computational probes for structural perception. The global paradigm demonstrated enhanced diagnostic sensitivity and exhibited cognitive resilience under simulated neuronal sparsity by maintaining structural recognition where local models suffered pattern collapse. Global modeling effectively unfolded the pathological manifold, revealing a linear trajectory of geometric degradation consistently correlated with clinical cognitive decline. These findings indicate that AD progression may be characterized as a systemic topological dissolution and suggest that effective biomarkers should prioritize hierarchical shape abstraction to accurately map the continuous transition from healthy cognition to dementia.

neuroscience↗

bioRxiv2026

A Modularized Stretchable Microneedle Array for Minimally Invasive and Efficient Drug Delivery

A novel Modularized Stretchable Microneedle Array (MSMA) is developed for minimally invasive and efficient drug delivery. By applying a modular design, the MSMA can be highly customized, offering versatility for different therapeutic applications. Its high stretchability allows for simultaneous stretching of both the microneedle and the skin, enhancing the penetration rate. Evaluations using tissue-mimicking materials and porcine skin demonstrated significant improvements in penetration efficiency and reduced residual strain. The MSMA achieved penetration rates of up to 89% on porcine skin under a minimum push-down distance of 2 mm. Moreover, the MSMAs ability to stretch and release in synchronization with the skin significantly reduces residual strain. This innovative platform promises reduced pain and discomfort, representing a substantial advancement in transdermal drug delivery technology.

bioengineering↗

bioRxiv2025

A Single-Aliquot, Enrichment-Free Workflow for High-Throughput Plasma Proteome and N-Glycoproteome Profiling

High cancer mortality rates highlight an urgent need for early detection. Plasma proteomics and glycoproteomics provide minimally invasive routes for biomarker discovery, yet achieving an optimal balance among profiling depth, throughput, and longitudinal reproducibility remains a major challenge for clinical application and translation. To overcome this bottleneck, we present a single-aliquot, enrichment-free, paired-run dual-omics pipeline that concurrently profiles the global plasma proteome and N-glycoproteome from unenriched plasma. Following depletion of top14 abundant plasma proteins, we implemented sequential 23-min narrow-window data-independent acquisition (DIA) and 42-min stepped-collision-energy data-dependent (SCE-DDA) runs from the same plasma digest, delivering a clinical throughput of [~]24 patients/day with deep proteome coverage of 3,756{+/-}413 protein groups (PGs) and 1,226{+/-}78 glycopeptides per sample, including 303 FDA-approved drug targets. Cross-platform benchmarking with a previous generation instrument demonstrated significantly faster (>10-20 fold) profiling speed to achieve 113 PGs/min and high protein abundance reproducibility (Pearson r > 0.9), confirming cross-instrument transferability. Application to a 300-participant lung cohort (cancer, LDCT-detected non-cancer nodules, and controls) revealed differential expression of S100 and annexin family proteins between cancer and nodules. Paired glycoproteomic analysis (n=30) identified site-specific N-glycosylation alterations in FN1, IGHG2, C3, and MET independent of total protein abundance, uncovering additional biomarker candidates for early lung cancer detection. Together, this dual-omics strategy enables deep, scalable, and reproducible plasma analysis, supporting longitudinal biomarker discovery and validation across instruments and laboratories.

biochemistry↗

bioRxiv2025

Evolutionary convergence of a Pyroptosis-Apoptosis crosstalk drives non-canonical inflammasome signalling.

The coordination of efficient immune responses to infections is essential to enable pathogen clearance and host survival. Cell death modalities are a crucial component of the innate immune system and are key to controlling intracellular and extracellular infections. Human caspase-4 and -5 are cysteine proteases activated upon intracellular detection of bacterial lipopolysaccharide (LPS) and triggers pyroptosis, a lytic and pro-inflammatory form of cell death. However, the interaction between these caspases and other cell death modalities remains poorly understood. Here, we build on evidence that caspase-4 can engage in crosstalk with the apoptotic executioner caspases-3 and -7. Our work validated caspase-3 and -7 as direct substrates of caspase-4 and -5, and demonstrated that this specificity was regulated by exosite interactions as opposed to the tetrapeptide. Using AlphaFold, we generated an interaction model between caspase-4 and executioner caspases-3 and -7. From this, we experimentally validated the importance of a hydrophobic interface on caspase-3 and -7 that engaged the caspase-4 exosite, enabling their recognition and cleavage. Importantly, this interface is not used by the apoptotic initiator caspase-8, which cleaved caspase-3 in a tetrapeptide-dependent manner. Our work highlights that inflammatory caspases have evolved a novel mechanism to coordinate crosstalk between pyroptotic and apoptotic signalling, and suggests that these pathways may synergise for the efficient amplification of cell death pathways.

biochemistry↗

bioRxiv2025

Evolutionary remodeling of non-canonical ORF translation in mammals

Non-canonical open reading frames (ncORFs) are pervasive within transcripts annotated as "non-coding" or "untranslated regions" of mRNAs, yet their landscape under normal physiological conditions remains to be fully resolved, particularly outside humans. Here we applied a stringent and standardized pipeline to hundreds of high-quality ribosome profiling libraries from normal mammalian tissues and cell types, identifying 11,623 human and 16,485 mouse ncORFs. Evolutionary analyses revealed that thousands of ncORFs are subject to coding constraint and exhibit lineage-specific conservation, underscoring their functional potential. Ancient ncORFs are preferentially highly translated, broadly expressed, and enriched for lineage-specific conservation. Co-expression patterns further indicate that many ncORFs, especially ancient ones, are cotranslated with canonical coding sequences, consistent with functions mediated through protein-protein interactions. Together, these findings establish a comprehensive atlas of mammalian ncORFs and provide fundamental insights into their evolutionary dynamics and functional integration within the proteome.

genomics↗

bioRxiv2025

Sodium Selenite Alleviates Hyperglycemia-aggravated Cerebral Ischemic Injury by Mediating Apoptosis through the Fas/FasL Signaling Pathway

ObjectiveTo investigate the intervention mechanism of sodium selenite in alleviating hyperglycemia-induced cerebral ischemia/reperfusion (I/R) injury through the Fas/FasL/NF-{kappa}B/PUMA pathway. MethodsThe SD rat model of hyperglycemia-induced cerebral I/R injury and the HT22 cell model of high-glucose oxygen deprivation/reoxygenation (OD/R) were constructed to systematically evaluate the neuroprotective effect of sodium selenite and its regulatory effect on the Fas/FasL/NF-{kappa}B/PUMA pathway. ResultsThe infarct volume, neurological dysfunction, metabolic level, and apoptosis level in the HG group were significantly higher than those in the NG group. Sodium selenite improved the infarct volume, neurological dysfunction, metabolic level, and apoptosis level in the HG group, and regulated the Fas/FasL/PUMA apoptotic pathway to alleviate injury. In vitro experiments showed that sodium selenite significantly improved morphological damage caused by high-glucose OD/R, increased cell viability, and reduced the expression of apoptotic factors. The application of Fas and FasL inhibitors and knockdown of PUMA expression indicated that sodium selenite alleviated cell apoptosis by inhibiting the activation of the Fas/FasL/PUMA pathway. ConclusionSodium selenite alleviates hyperglycemia-exacerbated cerebral I/R injury by regulating the Fas/FasL/NF-{kappa}B/PUMA signaling pathway.

pathology↗

bioRxiv2025

Untargeted Plasma Metabolomics in Canine Cognitive Dysfunction: The Naturally Occurring Alzheimer's Disease Analog in Dogs

IntroductionCanine Cognitive Dysfunction (CCD) is an increasingly prevalent naturally occurring neurodegenerative condition in senescent dogs that share neuropathological and clinical features with human Alzheimers disease (AD). Metabolic profiling allows for identification of new candidates for AD biomarkers, diagnostics, and therapeutics. Despite its translational potential, plasma metabolomic profiling of dogs with CDD has not been previously characterized. MethodsThis case-control study analyzed plasma samples from ten client-owned geriatric dogs, including five with severe CCD and five age-matched, clinically healthy controls. Untargeted plasma metabolomics was performed using ultra-performance liquid chromatography-mass spectrometry (UPLC-MS). Multivariate and univariate statistical analyses identified significant metabolic differences between the groups. Metabolites were considered significant based on a variable importance in projection (VIP) score > 1.5, fold change (FC) > 2.0, and adjusted p-value < 0.05. ResultsFifteen metabolites across seven chemical classes were significantly altered in CCD dogs compared to controls, including glycerophospholipids, steroid derivatives, indoles, and mitochondrial-related compounds. Notably, elevated lysophosphatidic acid (LPA 20:2/0:0) and reduced ubiquinone-2 levels suggest dysregulation in neuroinflammatory and oxidative stress pathways. Cholesterol exhibited the highest FC and VIP scores, further reinforcing its role in AD pathogenesis. Hierarchical clustering and pathway enrichment analyses supported distinct metabolic signatures in CCD that mirror those observed in human AD. DiscussionThis is the first untargeted plasma metabolomic profiling of dogs with CCD, revealing systemic metabolic disturbances that align with AD pathophysiology. Data was collected from senescent community-dwelling companion dogs, which enhances the studys ecological and translational relevance. It supports the utility of CCD as an AD model and highlight candidate plasma biomarkers that warrant further investigation. Future longitudinal studies integrating metabolomics with neuroimaging, histopathology, and behavioral assessments are required to validate these findings and contribute to AD biomarker discovery and therapeutic development.

neuroscience↗

bioRxiv2025

Beach sand beneath our feet: an overlooked reservoir of antibiotic resistance genes and pathogens, revealed by metagenomic evidence from Qingdao's recreational beaches

Coastal beach environments, especially those with heavy tourist activity, represent a dynamic interface between terrestrial and marine microbiomes. However, beach sand is rarely considered in surveillance of antibiotic resistance. In this study, we combined 16S rRNA gene sequencing and shotgun metagenomics to characterize microbial communities and antibiotic resistance genes (ARGs) at four popular recreational beaches in Qingdao, China. We show that beach sands harbor highly diverse bacterial communities with significantly greater richness than adjacent seawater. Beach sand near sewage discharge points had microbial profiles intermediate between raw sewage and open-ocean water, reflecting contributions from both sources. Metagenomic analysis identified a broad "resistome" of over 300 distinct ARGs in these beach and water samples, spanning 33 antibiotic classes and 6 resistance mechanism categories. Notably, the rifampicin resistance gene rpoB2 was the most abundant ARG, and genes conferring resistance to peptide antibiotics were prevalent. Sewage outfalls were found to be major contributors of ARGs, with waste-influenced sand containing a larger and more diverse ARG pool than sand farther from pollution sources. We also detected a high diversity of bacterial virulence factor genes, particularly in sand. Our findings highlight that tourist beaches can serve as reservoirs and mixing zones for antibiotic-resistant and potentially pathogenic bacteria from land-based pollution. This underscores the need to include beach sand in environmental monitoring for antibiotic resistance and to improve wastewater management at recreational coastlines to mitigate public health risks. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=198 SRC="FIGDIR/small/661489v1_ufig1.gif" ALT="Figure 1"> View larger version (84K): org.highwire.dtl.DTLVardef@18705f3org.highwire.dtl.DTLVardef@1979f8forg.highwire.dtl.DTLVardef@16c9029org.highwire.dtl.DTLVardef@6c778d_HPS_FORMAT_FIGEXP M_FIG C_FIG

microbiology↗

bioRxiv2025

Orco regulates the circadian activity of pheromone-sensitive olfactory receptor neurons in hawkmoths

1The mating behavior of nocturnal Manduca sexta hawkmoths is under strict temporal control. It is orchestrated via circadian and ultradian oscillations in sex-pheromone stimuli as social Zeitgeber. The extremely sensitive pheromone-detecting olfactory receptor neurons (ORNs) that innervate the long trichoid sensilla on the males antennae are peripheral circadian clocks. They express the transcriptional-translational feedback loop (TTFL) circadian clockwork, best characterized in Drosophila melanogaster. In hawkmoths, it is still unknown whether or how the ORN TTFL clockwork regulates the daily rhythms in pheromone sensitivity and in temporal resolution of ultradian pheromone pulses as prerequisites to the temporal regulation of hawkmoth mating behavior. We hypothesize that, rather than the slow TTFL clock, a more rapidly adaptive post-translational feedback loop (PTFL) clockwork, assembled in a signalosome in the ORN plasma membrane, allows for temporal control of pheromone detection via generation of multiscale endogenous membrane potential oscillations. The potential oscillations of the PTFL clock could rapidly synchronize to oscillations of pheromone stimuli at different time scales, thus enabling the prediction of stimulus patterns as a mechanism for active sensing. With in vivo long-term tip recordings of long trichoid sensilla of male hawkmoths, we analyzed the spontaneous spiking activity indicative of the ORNs endogenous membrane potential oscillations. Consistent with our hypothesis of a multiscale PTFL clock in hawkmoth ORNs, spontaneous spiking was modulated on ultradian and circadian time scales, with maximum activity at night. When we blocked the evolutionarily conserved olfactory receptor coreceptor (Orco), the circadian modulation was abolished but the ultradian frequency modulation of the spontaneous activity remained. Consistent with PTFL control, Orco was not under the transcriptional control of the TTFL clock, but its modulation of spontaneous spiking activity was dependent on cAMP. We could replicate the experimental data in a conductance-based computational model of an ORN. In this model, Orco conductance changed as a function of fluctuating 2nd messenger levels. This study demonstrates that a PTFL clock is sufficient to impose a circadian pattern on ORN sensitivity. Future experiments are necessary to further challenge our novel hypothesis. 2. Significance statementIt is generally assumed that all circadian rhythms in an organism are driven by a transcriptional-translational feedback loop (TTFL) clock. In this study, we demonstrate with in vivo recordings of hawkmoth pheromone-sensitive olfactory receptor neurons (ORNs) that the olfactory receptor coreceptor (Orco) is the key pacemaker channel for controlling circadian rhythms in spontaneous spiking activity. Since Orco expression is not driven by the TTFL clock, we put forward the novel hypothesis that Orco is a core element of a post-translational feedback loop (PTFL) membrane clock assembled in a signalosome controlling interlinked oscillations in 2nd messengers and membrane potential. Accordingly, our computational model predicts that ORN sensitivity is tuned by circadian changes in the conductance of an Orco ion channel, which is mediated by cycling levels of cyclic nucleotides. Our novel hypothesis that highlights the contribution of feedback-controlled post-translational modifications to the generation of endogenous circadian rhythmicity should spark further challenges.

physiology↗

bioRxiv2025

Metagenomic Analysis Reveals Northwest Pacific Ocean as a Reservoir and Evolutionary Hub of Antibiotic Resistance Genes

O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=200 SRC="FIGDIR/small/659680v1_ufig1.gif" ALT="Figure 1"> View larger version (81K): org.highwire.dtl.DTLVardef@139e191org.highwire.dtl.DTLVardef@10834c4org.highwire.dtl.DTLVardef@1c0544aorg.highwire.dtl.DTLVardef@1ddfd8a_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOGraphical abstractC_FLOATNO C_FIG Antibiotic resistance genes (ARGs) were identified as a novel type of environmental contaminants. Ocean is thought to be one of the ultimate environments where ARGs gathered. Marine ecosystems represent vast reservoirs of ARGs, yet their dynamics in open-ocean environments remain poorly characterized. Through large-scale metagenomic profiling of the Kuroshio Extension, a hydrographically dynamic region in the Northwest Pacific, we identified a striking enrichment of ARGs (1.81 x 10-3 ppm) at a frontal zone site (S30). The ARG abundance at this site exceeded coastal levels by 90-fold. Notably, multidrug resistance genes dominated this hotspot, with efflux pumps contributing 62% of the resistance mechanisms, a pattern distinct from the target-alteration strategies prevalent in other regions. The site exhibited unique microbial consortia, including pathogenic Acinetobacter (30.2% abundance) carrying clinically critical determinants (blaOXA-23, adeJ). Co-occurrence networks revealed horizontal transfer risks, linking pelagic Sphingobium to terrestrial-derived {beta}-lactamase variants. Crucially, we discovered three novel plasmid-borne resistance genes circulating in >15% of microbial populations, demonstrating open-ocean ARG diversification independent of direct anthropogenic inputs. These findings redefine oceanic frontiers as crucibles of resistance evolution, demanding urgent integration into global antimicrobial stewardship strategies.

microbiology↗

bioRxiv2025

BrainVAE: Exploring the role of white matter BOLD in preclinical Alzheimer disease classification

INTRODUCTIONLike gray matter (GM), white matter (WM) BOLD functional signals change in preclinical AD. However, the potential of WM BOLD for identifying preclinical AD remains underexplored. METHODSWe developed BrainVAE, a transformer-based variational autoencoder with interpretability, to classify preclinical AD and normal controls using resting-state fMRI data. We benchmarked BrainVAE against nine alternative models under three input configurations: WM-only, GM-only, and combined WM+GM. Interpretability analysis was also performed to investigate each brain regions contribution to the classification task. RESULTSBrainVAE outperformed other models and performed well (accuracy = 83.42%, F1-score = 91.62%, AUC = 64.50%) using the combined input compared to WM-only and GM-only. Specific WM bundles--including corpus callosum, fornix, and corticospinal tract--were among the most influential features contributing to the classification. DISCUSSIONIncorporating WM BOLD signals improves the distinction of preclinical AD from controls, underscoring the potential role of WM BOLD features for detecting early-stage AD. HighlightsO_LIBrainVAE integrates white and gray matter BOLD signals for classification of pre-AD and controls. C_LIO_LIBrainVAE achieves high accuracy (83.42%) and F1-score (91.62%) in identifying pre-AD. C_LIO_LIModels using combined WM+GM inputs outperform those using WM-only or GM-only inputs. C_LIO_LIWM regions, such as corpus callosum and fornix, contribute significantly to model predictions. C_LIO_LIResults suggest WM BOLD signals are informative markers for early AD detection. C_LI

neuroscience↗

bioRxiv2025

Modelling PRRS transmission between pig herds in Denmark and prediction of interventions impact

Porcine reproductive and respiratory syndrome (PRRS) is an endemic viral disease in most pigproducing countries, including Denmark. In 2022, Denmark launched a control program to reduce PRRS prevalence, with legislative changes in 2023 making testing and status reporting mandatory. The program also enforces the loss of PRRS-free status for farms that purchase pigs from non-PRRS-free sources and implements region-specific control measures to coordinate PRRS elimination within herds. However, the effectiveness of these interventions remains uncertain and requires thorough evaluation through transmission modelling and analysis of data before and after legislation changes. To understand PRRS transmission prior to legislative changes in 2023 and predict the impact of control measures, we developed a between-herd stochastic compartmental model. This model includes compartments for susceptible (S), highly infectious (Ih), lowly infectious (Il) and detected (D) pig herds, using data from 2020-2021. The model (i) quantifies the relative contributions of pig movements and local transmission to the spread of PRRS; (ii) generate herd-level maps of the basic reproduction (R0); and (iii) assess the effectiveness of targeted interventions for eradicating PRRS in Denmark. Model results indicated that more than 50% of herds had an R0 greater than 1, suggesting a potential for sustained transmission if no interventions had been implemented after 2022. Both local spread and movement-mediated transmission play important roles, but local transmission drives the spatial heterogeneity in observed PRRS prevalence across Denmark. Although only 17% of infectious herds remain undetected under current surveillance, they are responsible for 60% of total transmission. Local control via depopulation and repopulation, is the fastest measure to reduce the observed prevalence of PRRS, but it has a lower effect on true transmission due to the hidden infections. Therefore, achieving eradication may require a combination of more frequent testing, targeted within-herd PRRS elimination and stricter risk-based trading. This study identifies PRRS hotspots and transmission routes, offering evidence-based recommendations for control. HighlightsO_LIWe generated the first between-herd R0 map of PRRS transmission in Denmark C_LIO_LI17% of undetected herds are responsible for 60% of total PRRS transmission C_LIO_LIPositive stable herds are 50 times less infectious than positive unstable herds C_LIO_LILocal spread drives the spatial heterogeneity of PRRS transmission C_LIO_LIEradication requires multiple controls e.g., local controls, stricter risk-based trading and more frequent testing C_LI

ecology↗

bioRxiv2025

Harnessing the Power of Single-Cell Large Language Models with Parameter Efficient Fine-Tuning using scPEFT

Single-cell large language models (scLLMs) capture essential biological insights from vast single-cell atlases but struggle in out-of-context applications, where zero-shot predictions can be unreliable. To address this, we introduce a single-cell parameter-efficient fine-tuning (scPEFT) framework that integrates learnable, low-dimensional adapters into scLLMs. By freezing the backbone model and updating only the adapter parameters, scPEFT efficiently adapts to specific tasks using limited custom data. This approach mitigates catastrophic forgetting, reduces parameter tuning by over 96%, and decreases GPU memory usage by more than half, significantly enhancing scLLMss accessibility for resource-constrained researchers. Validated across diverse datasets, scPEFT outperformed zero-shot models and traditional fine-tuning in disease-specific, cross-species, and under-characterized cell population tasks. Its attention-mechanism analysis identified COVID-related genes associated with specific cell states and uncovered unique blood cell subpopulations, demonstrating scPEFTs capacity for condition-specific interpretations. These findings position scPEFT as an efficient solution for improving scLLMs utilities in general single-cell analyses.

cell biology↗

bioRxiv2025

Unraveling the mesoscale functional connectivity of the human primary visual cortex using high-resolution functional MRI.

Despite their importance for visual perception, functional connectivity between ocular dominance columns (ODCs)in the human primary visual cortex (V1) remains largely unknown. Using high- resolution functional MRI (fMRI), we localized ODCs and assessed their resting-state functional connectivity (rs-FC) in 12 human adults. Consistent with anatomical studies in animals, we found stronger rs-FC in the middle compared to deep and superficial cortical depths and selectively stronger rs- FC between ODCs with alike compared to unalike ocular polarity. Beyond what was known from animal models, and consistent with human perceptual biases, intra- and interhemispheric rs-FC was stronger in peripheral (compared to central) and in dorsal (compared to ventral) V1 subregions. Lastly, rs-FC patterns correlated with ODC maps, suggesting that ODC maps can be predicted from rs-FC patterns within V1. These results highlight the heterogeneity in rs-FC between ODCs across cortical depths and V1 subfields, underscoring their likely association with human perceptual features.

neuroscience↗

bioRxiv2025

PepGo: a deep learning and tree search-based model for de novo peptide sequencing

Identifying peptide sequences from tandem mass spectra is a fundamental problem in proteomics. Unlike search-based methods that rely on matching spectra to databases, de novo peptide sequencing determines peptides directly from mass spectra without any prior information. However, the design of models and algorithms for de novo peptide sequencing remains a challenge. Many de novo approaches leverage deep learning but primarily focus on the architecture of neural networks, paying less attention to search algorithms. We introduce PepGo, a de novo peptide sequencing model that integrates Transformer neural networks with Monte Carlo Tree Search (MCTS). PepGo predicts peptide sequences directly from mass spectra without databases, even without prior training. We show that PepGo surpasses existing methods, achieving state-of-the-art performance. To our knowledge, this is the first approach to combine deep learning with MCTS for de novo peptide sequencing, offering a powerful and adaptable solution for peptide identification in proteomics research.

bioinformatics↗

bioRxiv2025

Axon collateral pattern of a sparse locus coeruleus norepinephrine neuron in mouse cerebral cortex.

The locus coeruleus (LC) contains predominantly norepinephrine (NE) neurons that project widely throughout the brain. The LC plays a critical role in controlling behavior, particularly arousal. Historically, it was thought that the LC-NE system performed its behavioral control function by uniformly releasing NE throughout most brain regions. However, recent evidence suggests that the LCs cortical projections are organized into modules, which allows for the coordination of diverse, and sometimes opposing, functions such as fear memory formation and extinction. Nevertheless, many details remain unclear and require data from the axon collaterals of sparse neurons. We modified a viral tracing protocol using a dual-recombinase system to trace the axonal collaterals of sparse LC neurons projecting to the cingulate cortex (CgC). Our results show that even a small number of LC neurons have broad cortical projections, though the pattern is not uniform. Centered-log ratio transformation of NE fiber distribution across the cortex and hippocampus reveals a few preferential target areas (PTAs) of the labeled LC-NE neurons axonal projections. The summed NE fiber length in these defined PTs is enriched relative to the geometric mean of all other cortical and hippocampal regions where NE fibers were detected. Notably, the defined PTAs--including the rostral splenial cortex, dorsal hippocampus, somatosensory cortex, and CgC (the retrograde viral labeling injection site)--are functionally related to navigation. These results demonstrate that LC-NE neurons are organized into distinct projection modules, each comprising a small number of neurons with functionally correlated major cortical targets.

neuroscience↗