Biology subjects

Zheng, T.

Publications and source records attributed to Zheng, T..

At least 37 records · Page 2Linked to original sources

bioRxiv2026

Molecular and Cellular Underpinnings of Spatial Heterogeneity in Fetal Cortical Folding

Cortical folding is a defining feature of human brain development, yet the molecular and cellular mechanisms that produce regionally specific cortical folding remain incompletely understood. Here we combined high-resolution in-utero T2-weighted and diffusion MRI atlases (23-38 weeks of gestational age) with prenatal transcriptomic profiles to map regional macrostructural and microstructural features of cortical folding to underlying gene expression. We found genes whose expression patterns correlated with cortical curvature were enriched for neurogenesis, progenitor proliferation and radial glia guided neuronal migration, and localized to ventricular zone/subventricular zone progenitor cell subtypes, supporting for the protomap hypothesis of areal specification. By contrast, cortical microstructural markers-associated gene sets were implicated in myelination, cell adhesion and extracellular matrix remodeling, and mapped to astrocyte and endothelial cell programs. The microstructure-related gene expression peaked in the early postnatal period and remained high throughout childhood, while the curvature-associated gene expression reduced with age. Several of these cortical folding-related genes overlapped with autism spectrum disorder risk loci (e.g., SCN2A, STXBP1, DVL3). Collectively, these cross-modal findings outline a sequential developmental architecture--early progenitor driven patterning followed by myelin and extracellular matrix consolidation. In addition, we released a high-resolution fetal labeling atlas to facilitate further imaging-genetic studies of early cortical development.

neuroscience↗

bioRxiv2026

Therapeutic interleukin-2 rewires skeletal-immune circuits to reverse postmenopausal bone loss

Postmenopausal osteoporosis results from excessive osteoclast activity, but the immune circuits that limit osteoclastogenesis in the bone marrow remain poorly understood. Here, we tested a clinically accessible immunotherapy low-dose interleukin-2 (IL-2) as a therapeutic intervention in mice with established ovariectomy-induced bone loss, integrating microcomputed tomography imaging, single-cell transcriptomics, genetic perturbation, and human monocyte-osteoclast assays. Therapeutic administration of IL-2 reversed trabecular bone loss, expanded CXCR3 regulatory T cells in bone marrow, and promoted IL-10- and CGRP-producing ILC2s that were required for protection. IL-2 also acted directly on the osteoclast lineage, suppressing mouse and human osteoclastogenesis through activation of a STAT1-IRF1-dependent IFN program in RANKL-stimulated monocytes. Together, these data define an IL-2-responsive skeletal-immune network that can be therapeutically engaged to suppress osteoclastogenesis, which opens new avenues for cytokine-based immunotherapies in postmenopausal osteoporosis and related bone disorders.

immunology↗

bioRxiv2025

TMPO promotes cellular dissemination and metastasis in circulating tumor cells

Metastasis--the process by which cancer cells spread beyond the primary tumor to distant organs--accounts for the vast majority of cancer-related deaths. To elucidate mechanisms underlying dissemination and metastasis in prostate cancer, we have investigated circulating tumor cells (CTCs) obtained from genetically engineered mouse models (GEMMs). The phenotypic and molecular properties of the CTCs, and organoids derived from these CTCs, closely model the tumor and metastatic phenotypes of their parental GEMMs. Moreover, organoids derived from individual CTCs exhibit molecular and morphological heterogeneity that is associated with distinct metabolic states as well as differences in human prostate cancer outcome. Using computational systems analyses, we have identified TMPO, encoding the nuclear membrane protein lamina-associated polypeptide 2 (Lap2), as a key driver of this heterogeneity. TMPO activity is upregulated in advanced human prostate tumors, metastases, and CTCs, and is associated with adverse clinical outcome. Our findings indicate that TMPO promotes dissemination and metastasis in vivo by enhancing survival in conditions of metabolic stress, and reveal a novel mechanistic link between CTC heterogeneity, stress adaptation, and metastatic potential.

cell biology↗

bioRxiv2025

RNA modulates FUS condensate assembly, dynamics, and aggregation through diverse molecular contacts

Fused in sarcoma (FUS) is an RNA-binding protein that undergoes phase separation with RNA and other cellular components, forming ribonucleoprotein (RNP) granules. While recent advances delineating the molecular forces that underlie phase separation have largely focused on protein-protein interactions (1-6), the molecular details of protein-RNA interactions within condensates remain limited. In this study, we demonstrate that RNA modulates the phase separation of the low-complexity (LC) and arginine-glycine-glycine motif (RGG1) domains of FUS: low RNA concentrations enhance protein phase separation and excess RNA disrupts it. By integrating biochemical assays, NMR spectroscopy, and molecular dynamics simulations, we show that RNA incorporates into FUS condensates, reducing condensate density while enhancing local relaxation and diffusional motion of FUS. Surprisingly, whereas RNA binding in the dispersed phase primarily involves the RGG1 domain, within the condensed phase, both LC and RGG1 domains contribute to interactions with RNA. NMR and simulation data show diverse interactions between amino acids and RNA moieties, including prominent glutamine-RNA contacts, that stabilize FUS-RNA co-condensates. Furthermore, we found that RNA accelerates the liquid-to-solid transition of FUS LC-RGG1 condensates, promoting fibrillar aggregate formation. Together, these results provide mechanistic insight into how RNA regulates the assembly, dynamics, and maturation of protein condensates. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=121 SRC="FIGDIR/small/694118v1_ufig1.gif" ALT="Figure 1"> View larger version (41K): org.highwire.dtl.DTLVardef@19168a9org.highwire.dtl.DTLVardef@16e6878org.highwire.dtl.DTLVardef@18cb8a9org.highwire.dtl.DTLVardef@1af6a4c_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOGraphical AbstractC_FLOATNO Using NMR and molecular simulations, we map how RNA engages FUS LC-RGG1 within condensates through electrostatic, {pi}-stacking, and hydrogen-bond contacts. We find that RNA incorporation dilutes condensate density, tunes protein mobility, remodels interaction networks, and accelerates the formation of fibrillar aggregates. C_FIG

biochemistry↗

bioRxiv2025

ABA-responsive transcription factor CbNAC63 is involved in modulating biosynthesis of triterpenoid saponins in Conyza blinii

Conyza blinii, a traditional Chinese medicinal herb, accumulates triterpenoid saponins. NAC transcription factors (TFs) are pivotal for plant stress responses and hormone-mediated secondary metabolism, while abscisic acid (ABA) regulates terpenoid biosynthesis in medicinal plants. However, how NAC TFs mediate ABA-regulated triterpenoid saponin synthesis in C. blinii remains unclear. In order to address this gap, the focus was directed towards CbNAC63--a NAC TF identified from the nocturnal low-temperature transcriptome of C. blinii. Phylogenetic and motif analyses showed it belongs to the stress-responsive NAC subclade with conserved domains. Y2H assays revealed its self-interaction, enhancing transcriptional activity; subcellular localization confirmed nuclear localization. RT-qPCR results indicated CbNAC63 exhibits tissue-specific expression under nocturnal low-temperature stress, accompanied by increased triterpenoid saponin accumulation. ABA signaling primarily regulates this process: exogenous ABA enhanced CbNAC63 expression and saponin content, while fluridone suppressed both. Overexpression (OE) and virus-induced gene silencing (VIGS) demonstrated CbNAC63 positively regulates saponin biosynthesis. Y1H and dual-luciferase reporter assays confirmed CbNAC63 directly binds to the promoters of Cb{beta}AS and CbHMGR and activates their transcription. In summary, the study shows CbNAC63 integrates ABA and low-temperature signals, activating MVA pathway genes to regulate saponin synthesis. This unveils a novel "ABA-CbNAC63-MVA" module, enriches the classic regulatory network, and provides a target for improving medicinal plant quality. HighlightsIdentifies CbNAC63 as a novel regulator that integrates ABA and cold signals to boost saponin production in medicinal plants.

plant biology↗

bioRxiv2025

Immune-Derived THBS1-CD47 Axis Induces Cellular Senescence and Suppresses Osteogenesis in Diabetic Periosteum

Type 2 diabetes mellitus (T2DM) weakens bone repair and increases fracture risk, but how the periosteal environment contributes to this problem is not fully understood. We found that diabetic mice showed thinning of the periosteum, reduced bone mass, and poor function of bone-forming cells. Using single-cell RNA sequencing, we discovered that immune cells and bone-lineage cells interact more strongly in diabetes through the THBS1-CD47 pathway. THBS1 was mainly produced by macrophages, while its receptor CD47 was abundant in osteogenic cells. Laboratory experiments showed that THBS1 blocked bone gene activity, increased inflammation and cell death, and damaged mitochondria, leading to higher oxidative stress. Knocking down CD47 reversed these effects, restoring bone cell activity and energy balance. In diabetic fracture models, blocking THBS1 improved callus formation and bone healing. These findings identify THBS1-CD47 as a key driver of periosteal dysfunction in T2DM and highlight it as a potential target to improve skeletal repair in diabetic patients.

cell biology↗

bioRxiv2025

Fix or Freeze? Spectral Differences Arising from Tissue Preparation in Chemical Imaging

Spectrochemical imaging has emerged as a powerful, label-free modality for visualizing the bio-chemical composition of tissues based on intrinsic vibrational signatures. Specifically, mid-infrared spectrochemical imaging (MIRSI) is becoming essential for fundamental biomedical research studying disease mechanisms, identifying biomarkers, and guiding drug development. However, the sensitivity of MIRSI to sample preparation protocols and its impact on spectral data interpretation remain poorly characterized. Here, we systematically compared spectral data collected from rat kidney and liver tissues prepared using standard fresh frozen (FF) and formalin-fixed, paraffin-embedded (FFPE) tissue processing methods using quantum cascade laser (QCL)-based MIRSI. We applied frequently used spectral data processing techniques, including uniform manifold approximation and projection (UMAP), correlation matrices, and second-derivative spectral analysis, to characterize preparation-induced differences. FF samples preserved a broader range of biochemical signals, retaining the innate chemical composition of tissues, while FFPE tissues showed reduced spectral diversity and absorption signal intensity. Moreover, a unique spectral band at 1026 cm-1, likely arising from formalin-induced collagen crosslinking, was identified specifically in FFPE samples. Our findings demonstrate that tissue preparation substantially alters chemical and morphological information captured by MIRSI, necessitating careful consideration of processing protocols in workflows involving chemical imaging and Artificial Intelligence (AI) - based spectral analysis.

biochemistry↗

bioRxiv2025

BMP-Smad1/9 signaling is required for PGC proliferation in zebrafish

The specification and maintenance of germ cell lineage are vital for reproductive development and heredity. The germ cell fate in some species, such as zebrafish and Xenopus, is determined by maternally supplied germ plasm, whereas in mammals it is induced by bone morphogenetic protein (BMP) signaling after implantation. It remains elusive whether BMP signaling is implicated in zebrafish germ cell development. Here, we demonstrate that, in zebrafish, BMP-Smad1/9 signaling is required for primordial germ cell (PGC) maintenance but not for PGC fate determination or migration. BMP inhibitor treatment or whole-embryo smad1/9 knockdown reduces the number of PGCs. To investigate cell-autonomous roles of BMP-Smad1/9 in PGCs, we generated PGC-specific smad1/9 knockouts using a double-transgenic approach with PGC-specific expression of Cas9 and ubiquitous expression of guide RNAs (gRNAs). Loss of Smad1/9 in PGCs leads to impaired PGC proliferation and increased apoptosis, resulting in reduced PGC numbers and adult sex bias. Moreover, transcriptome analysis of smad1-deficient PGCs revealed no significant changes in the expression of PGC-specific genes, but a marked upregulation of genes involved in cell cycle checkpoints and DNA damage repair. Notably, ectopic ATR-pChk1 activation in smad1-cKO PGCs validates cell cycle defects and DNA replication stress. ATR inhibition restores PGC numbers in mutant embryos. Collectively, these findings underscore a critical role of BMP-Smad1/9 signaling in zebrafish PGC population maintenance, while it is dispensable for PGC fate determination and migration.

developmental biology↗

bioRxiv2025

Visualizing TERRA RNA G-quadruplex unfolding in FUS biomolecular condensates

RNA G-quadruplexes (rG4s) are remarkably stable secondary structures with critical regulatory roles in gene expression, RNA metabolism, and telomere maintenance. However, their behavior within cells remains controversial, partly due to challenges in detecting rG4s in complex environments. Here, we use solution NMR spectroscopy to investigate how condensates formed by the low-complexity and RGG domains of the RNA-binding protein FUS affect the structure of TERRA, a highly stable model rG4 RNA. We show that FUS LC-RGG1 interacts with TERRA in dilute solution and that binding perturbs, but does not disrupt, the G-quadruplex structure. When co-phase separated with FUS LC-RGG1, however, NMR signatures of TERRAs folded state disappear, and the remaining observable resonances indicate an unfolded conformation, even in buffer containing potassium where TERRA rG4 is exceptionally stable when outside a condensate. Quantitative comparisons with a mutant form of TERRA, used as a baseline for fully unfolded RNA, suggest that at minimum a third of TERRA RNA becomes unfolded in the condensed phase. Thus, our results demonstrate that condensates can shift the structural ensemble of rG4 towards unfolded species, offering a potential mechanistic explanation for their apparent lack of stability in vivo and revealing how phase-separated environments may actively modulate RNA structure and function. HighlightsO_LINMR spectroscopy directly probes RNA structure inside biomolecular condensate. C_LIO_LIFUS binding in solution perturbs TERRA RNA G-quadruplex. C_LIO_LIA sizable fraction of TERRA is unfolded in FUS condensates. C_LI

biochemistry↗

bioRxiv2025

Gene-centric metagenomic analyses reveal microbiome functional insights into diseases

The microbiome encodes millions of genes; however, understanding their role in human health remains challenging. Here, we developed MetaGEAR, a gene-centric analysis framework for metagenomic data. MetaGEAR constructs cohort-specific databases for efficient retrieval of gene annotations, abundances, and co-localization, while providing enhanced taxonomic resolution by integrating reference- and assembly-based approaches. This is combined with a Metagenomic Assembled Graph (MAGraph) capturing gene neighborhood information. Using MetaGEAR, we built a multi-cohort database comprising >33 million gene families to investigate microbiome functionality across 24 cohorts of inflammatory bowel disease, colorectal cancer, and healthy populations and identified disease signature genes. Furthermore, the MAGraph revealed mobile genetic elements acting as hubs for tetracycline resistance spreading among Enterococcus, Streptococcus, and Veillonella species. Also, a duplicated nitrate reduction operon in Klebsiella pneumoniae was linked to differential gene expression under stress and virulence-inducing conditions. In summary, gene-centric metagenomic analyses reveal important insights into microbiome functionality in diseases.

microbiology↗

bioRxiv2025

Serial Imaging of Tumor and microEnvironment (SITE) platform for live-cell ex vivo modeling of primary and metastatic cancer dynamics.

Understanding cancer initiation and progression is extremely challenging, in part due to experimental limitations in measuring and interpreting key signalling and tumour-microenvironment (TME) interactions that determine changes in cell and tissue behaviours over time. Here we developed SITE (Serial Imaging of Tumour and microEnvironment), a spatially-and temporally integrated, modular, ex vivo platform enabling quantitative analysis of TME interaction dynamics, signalling, and cell fate at single cell and tissue scales. Applied to modelling primary and lung metastatic breast cancer, SITE revealed tissue-specific TME interactions and ERK signalling patterns linked to distinct single-cell behaviours. We found that the earliest steps in tumour establishment and metastatic seeding involved active cell protrusion and the establishment of a multicellular niche interfacing tumour and host. Experimental and mathematical modelling showed that ERK signalling was co-influenced by these interactions, where cancer cluster formation increased signalling via the establishment of local signalling circuits. Disruption of these signalling circuits led to tissue-specific impacts on cancer intrinsic and TME interaction dynamics. Here, we modelled breast cancer as a test case, demonstrating the broad utility of SITE for quantitative exploration of TME interaction dynamics- closing a significant gap in experimental capabilities between in vivo models and in vitro systems.

cancer biology↗

bioRxiv2025

Full-Field Analysis Indicates Late Reperfusion Therapy Broadens and Mechanically Smooths the Borderzone During Post-Infarction Inflammation

Late reperfusion therapy (LRT; [≥] 3 hours post-MI) significantly reduces the risk of ventricular rupture following myocardial infarction (MI), yet the structural and mechanical mechanisms behind this protection remain unclear. We hypothesized that LRT would alter the biomechanical properties of the infarct borderzone and to investigate this, we utilized laser micrometry, planar biaxial testing, and quantitative polarized light imaging (QPLI) to quantify spatial variations in the geometric, mechanical, and structural properties of the left ventricle extracellular matrix (LV ECM) in adult male Sprague-Dawley rats. Rats received permanent occlusion (PO), LRT, or a sham surgery and tissue was collected 1-day post-MI, during the inflammatory phase of healing. LRT generated a larger infarct borderzone (LRT: 31.5 {+/-} 7.6 mm2; PO: 22.5 {+/-} 4.2 mm2; p < 0.05) in comparison to PO. Infarct core and borderzone stiffness was reduced post-MI, and LRT samples exhibited smoother, more consistent stiffness gradients between infarct core and remote regions than PO samples. In general, infarcted LV ECM from were thicker and more spatially variable than sham samples, but less stiff. Additionally, dynamic QPLI revealed decreased collagen fiber alignment in infarct cores relative to borders, though this did not differ between PO and LRT groups. Complementary second harmonic generation imaging revealed more gradual, consistent transitions in collagen fiber alignment throughout LV ECMs subjected to LRT, although this was limited to one sample from each group. Ultimately, these results further justify LRT and may inform future therapeutic strategies aimed at spatially modulating post-MI tissue mechanics to improve patient outcomes.

bioengineering↗

bioRxiv2025

Fast and sensitive multiplexed diagnostic system enabled by real-time solid-phase PCR assay

Simultaneous identification of multiple nucleic acid targets is pivotal for high-throughput analysis in clinical diagnostics. Unfortunately, conventional PCR offers limited multiplexing capability due to issues like primer interference, fluorescence spectral overlaps and instrumentation complexity. Solid-phase PCR (SP-PCR), in which primers are physically separated on a solid support, has emerged as an alternative strategy for detection of multiple targets in parallel. However, SP-PCR has been suffering from low efficiency, long reaction time, inability for real-time signal monitoring and accurate quantification, which greatly restricts their applications in multiplexed assays. In this study, we presented for the first time a compact and portable flow-through SP-PCR platform to permit rapid, highly efficient and quantitative solid-phase amplification. We designed an integrated platform comprising a novel mechanically actuated valving system and a dual-chamber SP-PCR system to enable automated sample purification and amplification. Active oscillating the PCR solution between the chambers significantly enhanced the mass diffusion over the solid-phase array. Moreover, after each amplification cycle, the PCR solution was separated from the solid-phase-bound probes, thereby eliminating background signal interference and allowing for real-time monitoring of SP-PCR signals without the need for complex optical systems. The flow-through SP-PCR system demonstrated quantitative detection of five viral pathogens in a single reaction, with a limit of detection of 10 copies per reaction within 20 minutes. This platform provides a promising high-throughput, low-cost and simple-instrumentation multiplexed diagnostic system.

molecular biology↗

bioRxiv2025

Stage- and tissue-specific gene editing using 4-OHT inducible Cas9 in whole organism

Vertebrate genes usually function in specific tissues at specific stages, and thus their functional studies require conditional knockout or editing. In the zebrafish, spatiotemporally inducible genome editing, especially during early embryonic development, is still challenging. Here, we report inducible Cas9-based gene editing in specific cell types at desired stages in zebrafish. We show that the nCas9ERT2 fusion protein consisting of Cas9 and estrogen receptor flanked by two nuclear localization signals is normally located in the cytoplasm and efficiently translocated into the nucleus upon 4-hydroxytamoxifen (4-OHT) treatment in cultured cells or embryos. As a proof-of-concept, we demonstrate that target genes in primordial germ cells or germ cells of transgenic zebrafish embryos or adults with stable expression of nCas9ERT2 and gene-specific guide RNAs (gRNAs) can be induced to mutate by application of 4-OHT. This inducible nCas9ERT2 system also works in mouse early embryos. Thus, this inducible gene editing approach will be another choice for studying the temporospatial function of genes at the organismal level. Hence, the inducible nCas9ERT2 system expands the tissue- and stage-specific gene editing toolkit.

developmental biology↗

bioRxiv2025

Beyond the Axoneme: Whole-Cell Proteomics Identifies Novel Regulators of Ciliogenesis in Xenopus Epidermal Multiciliated Cells

Motile cilia generate directional fluid flow critical for development and tissue homeostasis, and their dysfunction underlies a range of human diseases. Prior proteomic studies have focused on isolated axonemes, leaving the regulatory components of ciliogenesis located in other cellular compartments of multiciliated cells (MCCs) largely unidentified. To bridge this gap, we performed whole-cell proteomic profiling of MCCs in Xenopus using an inducible system that enables selective MCC-enrichment. Leveraging a single-vessel in-cell proteomics approach with ultra-high sample preservation, we identified over 9,000 proteins, including 832 upregulated in MCCs. These encompassed both established ciliary components and novel candidates localized to distinct ciliary structures. Functional validation confirmed the involvement of previously uncharacterized proteins in ciliogenesis. This study presents a high-resolution, whole-cell proteome of vertebrate MCCs, providing critical insights into the molecular networks that govern ciliogenesis and offering a valuable resource for understanding the mechanisms of cilia-related disorders.

developmental biology↗

bioRxiv2025

Dextran-based T-cell expansion nanoparticles for manufacturing CAR T cells with augmented efficacy

Adoptive T cell therapy (ACT) using chimeric antigen receptor (CAR) engineered T cells is currently being explored in multiple cancer types beyond leukemia/lymphoma. A key step in CAR-T cell manufacturing is the activation and expansion of T cells, which facilitates viral transduction, however, may hamper T cell fitness and reduce in vivo persistence. We developed "T-Expand" for T cell activation and expansion, comprising dextran-based nanoparticles (NPs) conjugated with anti-CD3 and anti-CD28 antibodies. The NPs triggered robust polyclonal expansion of human T cells with efficiency in the range of commercial microbeads (Dynabeads). Engineered in presence of T-Expand, CD19 CAR T cells exhibited enhanced proliferative capacity, cytotoxicity and persistence in vitro, and furthermore, showed superior anti-lymphoma activity in mouse models resulting in complete tumor clearance at one fourth of the CAR T cell dose. Importantly, T-Expand is biocompatible with no observed toxicity, circumventing removal steps after T cell expansion compared to DynabeadsTM. As a biocompatible T cell expansion platform, T-Expand simplifies the manufacturing process while enhancing T cell persistence and functionality, thereby holding promise for increasing clinical efficacy of CAR T cell therapy. O_FIG O_LINKSMALLFIG WIDTH=165 HEIGHT=200 SRC="FIGDIR/small/648181v1_ufig1.gif" ALT="Figure 1"> View larger version (74K): org.highwire.dtl.DTLVardef@35337corg.highwire.dtl.DTLVardef@c75199org.highwire.dtl.DTLVardef@1be184forg.highwire.dtl.DTLVardef@12e1683_HPS_FORMAT_FIGEXP M_FIG Graphical abstract/Cover figureIllustration of CAR T cell manufacturing using T-Expands ex vivo. C_FIG

immunology↗

bioRxiv2024

Convincing Evidence of Carnivorous Diet in Alvarezsaurian Dinosaur

A dietary shift from carnivory to insectivore has been proposed to explain the dramatic morphological evolution of alvarezsaurians, particularly the adaptation related to the manual digital reduction and body size miniaturization. However, based solely on morphological shifts, this hypothesis lacked direct dietary evidence to support either carnivory or insectivore. Here, we present the first convincing dietary evidence for alvarezsaurians, derived from the intestinal contents of the Early Cretaceous Bannykus wulatensis. Our analysis revealed significantly higher levels of calcium and phosphorus in the intestinal contents compared to the surrounding sandstone. Scanning electron microscopy identified hard tissue debris and possible soft tissues surrounding by phosphatized bacteria and tightly packed hollow microspheres, suggesting that the intestinal contents were strongly pseudomorphed by phosphatized microbes during fossilization. Raman spectroscopy showed characteristic peaks indicative of bone-derived material, consistent with the hard tissue debris appeared in the intestinal contents. Our results suggest that Bannykus had a carnivorous diet with strong chemical digestion, which likely compensated for its delicate cranial structures and small teeth. These results imply that if a dietary shift to insectivore occurred, it likely took place later in alvarezsaurian evolution, probably coinciding with a reduction in body size.

paleontology↗

bioRxiv2024

After-effects of Parieto-occipital Gamma Transcranial Alternating Current Stimulation on Behavioral Performance and Neural Activity in Visuo-spatial Attention Task

Visuo-spatial attention enables selective focus on spatial locations while ignoring irrelevant stimuli, involving both endogenous and exogenous attention. Recent advancements in transcranial alternating current stimulation (tACS) have shown promise in modulating these attentional processes by targeting electrical oscillations in specific brain areas. Despite evidence of online effects of tACS on visuo-spatial attention performance, whether tACS can produce lasting after-effects on behavioral performance and neural activity remains unknown. This study explored these after-effects using a single-blind, sham-controlled, between-group design. Eighteen young healthy participants were equally divided into two groups receiving either sham or active gamma tACS at 40 Hz targeted at the right parieto-occipital region. Each participant performed a version of the Posner cueing task with EEG recording before and after the tACS intervention. The active tACS group exhibited greater reductions in reaction time compared to the sham group. These changes were not uniform across different attention types, suggesting specific enhancements in cognitive processing. EEG analyses revealed trial-type-specific modulation of event-related potentials, including amplitude and latency of N1 and P3 components, that paralleled the behavioral effects. Additionally, frequency-specific changes in oscillatory power during the cue-target interval--decreased alpha power and increased gamma power--as well as reduced long-range temporal correlations were observed more broadly across conditions. While limited by a small sample size, these preliminary findings provide convergent behavioral and electrophysiological evidence that parieto-occipital gamma tACS can induce lasting, condition-specific after-effects on visuo-spatial attentional networks.

neuroscience↗