Biology subjects

Zhang, Z.

Publications and source records attributed to Zhang, Z..

At least 433 records · Page 24Linked to original sources

bioRxiv2025

Cholinergic modulation of dopamine release drives effortful behavior

Effort is costly: given a choice, we tend to avoid it1. But in many cases, effort adds value to the ensuing rewards2. From ants3 to humans4, individuals prefer rewards that had been harder to achieve. This counterintuitive process may promote reward-seeking even in resource-poor environments, thus enhancing evolutionary fitness5. Despite its ubiquity, the neural mechanisms supporting this behavioral effect are poorly understood. Here we show that effort amplifies the dopamine response to an otherwise identical reward, and this amplification depends on local modulation of dopamine axons by acetylcholine. High-effort rewards evoke rapid acetylcholine release from local interneurons in the nucleus accumbens. Acetylcholine then binds to nicotinic receptors on dopamine axon terminals to augment dopamine release when reward is delivered. Blocking the cholinergic modulation blunts dopamine release selectively in high-effort contexts, impairing effortful behavior while leaving low-effort reward consumption intact. These results reconcile in vitro studies, which have long demonstrated that acetylcholine can trigger dopamine release directly through dopamine axons6-11; with in vivo studies that failed to observe such modulation12-14, but did not examine high-effort contexts. Our findings uncover a mechanism that drives effortful behavior through context-dependent local interactions between acetylcholine and dopamine axons.

neuroscience↗

bioRxiv2025

Spatial Transcriptomics Analysis Uncovers ER stress in MANF-deficient Purkinje Cells Underlying Alcohol-induced Cerebellar Vulnerability in Mice

Cerebellar Purkinje cells (PCs) are among the most vulnerable neurons to alcohol neurotoxicity. Alcohol can induce endoplasmic reticulum (ER) stress and alter the structure and function of PCs. Mesencephalic astrocyte-derived neurotrophic factor (MANF) is an ER stress inducible protein highly expressed in PCs. It is neuroprotective in various pathological conditions where ER stress is induced. However, it is unknown whether MANF plays a role in protecting PCs from alcohol induced ER stress. In this study, we generated PC-specific MANF knockout (KO) mouse model to test the hypothesis that MANF deficient PCs are more susceptible to binge alcohol exposure induced ER stress and neurodegeneration in the adult brain. We found that PC-specific MANF KO animals show moderate motor function deficit, which was exacerbated by alcohol exposure. Interestingly, female KOs were more sensitive than male KOs to alcohol-induced motor function impairments. In accordance with the behavior changes, alcohol exposure also caused UPR activation, increased intranuclear expression of calcium binding protein Calbindin, and PC degeneration in female but not male MANF KO mice. Spatial transcriptomics and high throughput in situ analyses demonstrated that MANF deficiency altered the transcriptomic landscape in PCs in a sex-specific manner and triggered the expression of genes involved in protein folding and response to ER stress. These results suggests that MANF KO PCs may be predisposed with a higher risk to UPR activation and ER stress in a sex dependent manner, contributing to their vulnerability to alcohol neurotoxicity.

molecular biology↗

bioRxiv2025

Human myelocyte and metamyelocyte-stage neutrophils suppress tumor immunity and promote cancer progression

Tumor-infiltrating neutrophils (TINs) are highly heterogeneous and mostly immunosuppressive in the tumor immune microenvironment (TIME). Current biomarkers of TINs and treatment strategies targeting TINs have not yielded optimal responses in patients across cancer types. Here, we separated human and mouse neutrophils into three developmental stages, including promyelocyte (PM), myelocyte & metamyelocyte (MC & MM), and banded & segmented (BD & SC) neutrophils. Based on this separation, we observed the predominance of human but not mouse MC & MM-stage neutrophils in bone marrow (BM), which exhibit potent immunosuppressive and tumor-promoting properties. MCs & MMs also occupy the majority of TINs among patients with 17 cancer types. Moreover, through the creation of a NCG-Gfi1-/- human immune system (HIS) mouse model, which supports efficient reconstitution of human TIN, we found a significant increase of BM MCs & MMs in tumor-bearing mice. By comparing the scRNA-seq analysis results of human neutrophils from both BM and tumors, we found CD63 and Galectin-3 distinguish MC & MM from neutrophil populations in cancer patients. Furthermore, we proposed a strategy with Flt3L to specifically induce the trans-differentiation of MCs & MMs into monocytic cells, and trigger tumor control in NCG-Gfi1-/- HIS mice. Thus, our findings establish an essential role of human MC & MM-stage neutrophils in promoting cancer progression, and suggest their potential as targets for developing potential biomarkers and immunotherapies for cancer.

immunology↗

bioRxiv2025

Alginate Oligosaccharides (from DP2 to DP9) Differentially Modulate Phytohormone Levels in Botrytis cinerea-Infected Wheat

BackgroundAlginate oligosaccharides (AOS) are emerging biostimulants known to modulate plant defense and growth hormones. However, the influence of AOS chain length--defined by degree of polymerization (DP)--on multiple phytohormones in wheat under pathogen stress has not been systematically evaluated. MethodsWheat seedlings (cv. Bobwhite) were pretreated 24 h before inoculation with Botrytis cinerea using AOS fractions of DP 2-9 (100 mg L-{superscript 1}). Leaves were harvested 48 h post-inoculation, and seven hormones--jasmonic acid (JA), salicylic acid (SA), indole-3-acetic acid (IAA), cytokinins (CTK), abscisic acid (ABA), ethylene (ET), and gibberellins (GA)--were quantified by LC-MS/MS (JA, SA, IAA, CTK, ABA, GA) or GC-FID (ET). Data represent mean fold-changes (n = 5 biological replicates) relative to untreated controls, with significance assessed by two-tailed t-tests (p < 0.05). ResultsAOS effects were highly DP-dependent. JA peaked at DP 4 (2.50-fold; p = 3.12 x 10-) then declined at higher DPs. SA induction was greatest at DP 3 (3.20-fold; p = 8.90 x 10-). IAA and GA both maximized at DP 5 (2.30-fold; p = 5.67 x 10- and 2.34-fold; p = 7.24 x 10-, respectively). CTK and ABA each showed highest accumulation at DP 6 (2.40-fold; p = 4.12 x 10- and 3.00-fold; p = 2.34 x 10-). In contrast, ET was most strongly suppressed by DP 7 (0.416-fold; p = 5.54 x 10-). All DP treatments differed significantly from control (p < 0.05). ConclusionsThe degree of polymerization critically governs AOS-mediated modulation of phytohormones in wheat under B. cinerea stress. Mid-range oligomers (DP 4-6) optimally enhance defense-related hormones (JA, SA, ABA, CTK), while slightly longer chains (DP 7) most effectively suppress ET. These insights enable the tailored selection of AOS fractions to bolster disease resistance and growth in cereal crops.

plant biology↗

bioRxiv2025

Poldip2 deficiency attenuates disease severity in a mouse model of COVID-19

The lungs are the primary target of severe acute respiratory syndrome coronavirus 2 (SARS-CoV- 2), with the infection resulting in lung inflammation, pulmonary vascular leakage and diffuse alveolar damage. Polymerase delta-interacting protein-2 (Poldip2) mediates lung inflammation and vascular permeability after lipopolysaccharide-induced acute respiratory distress syndrome; however, its role in regulating lung permeability, vascular inflammation and tissue damage following SARS-CoV-2 infection is completely unknown. Here, we assessed the role of Poldip2 in inflammation, immune cell infiltration and lung tissue damage in response to SARS-CoV-2 infection. Our data shows that while deletion of Poldip2 does not affect the susceptibility to SARS- CoV-2 infection, mice heterozygous for Poldip2 exhibit reduced lung tissue damage, reduced cytokine and chemokine induction and decreased infiltration of myeloperoxidase (MPO)-positive neutrophils into inflamed lung tissue. These data reveal that Poldip2 depletion mitigates inflammation and immune cell infiltration following SARS-CoV-2 infection, highlighting the therapeutic potential of Poldip2 inhibition to attenuate severe lung injury.

pathology↗

bioRxiv2025

APALORD: An R-based tool for differential alternative polyadenylation analysis of long-read RNA-seq data

Alternative polyadenylation (APA) is a critical co/post-transcriptional process that enhances RNA isoform diversity, regulating mRNA stability, localization and translation in a spatiotemporal manner. Over the past decade, long-read (LR) RNA sequencing techniques have advanced rapidly, producing datasets that could offer insights into APA mechanisms. Here we introduce APALORD (Alternative Polyadenylation Analysis of LOng-ReaDs), an R-based analysis tool for APA analysis of LR RNA-seq data. Leveraging precise 3 end information from 3-primed LR RNA-seq data, APALORD identifies polyadenylation sites (PASs) and quantifies PAS usage (PAU) at individual sites for each sample. It conducts APA analysis at the gene level (using Kolmogorov-Smirnov test) and at the level of individual PAS (using DEXSeq) across sample conditions. APALORD was applied to direct RNA-seq data from human embryonic stem cells (hESCs) and hESC-derived neurons. PASs were identified with high accuracy and a transcriptome-wide 3UTR lengthening trend was found, consistent with previous studies. APALORD analysis of PacBio cDNA data from human tissues confirmed a 3UTR lengthening trend in cortex compared to liver. R2C2 libraries generated on the Nanopore platform were analyzed with APALORD and it revealed APA change associated with polysome fractions in human neural progenitor cells. In summary, APALORD offers a comprehensive framework for differential APA analysis using LR RNA-Seq data, empowering researchers to investigate 3 end dynamics across diverse biological contexts.

bioinformatics↗

bioRxiv2025

Mapping genetic modifiers of epimutation rates reveals a punctuated-equilibrium model of CG methylome evolution

Spontaneous epimutations--stochastic changes in cytosine methylation--can persist across generations in plants and are thought to contribute to phenotypic variation. Although epimutations are increasingly studied for their potential long-term effects, it remains unclear why their accumulation varies across genotypes. Here, we tracked DNA methylation across ten generations in [~]400 mutation accumulation lineages derived from [~]70 Arabidopsis Ler x Cvi recombinant inbred lines. Treating epimutation rates as quantitative molecular traits, we mapped a major QTL to a Cvi-derived deletion near VIM2 and VIM4, two genes involved in CG methylation (mCG) maintenance. We show that this deletion rapidly reduces genome-wide methylation to a lower steady-state and compromises mCG maintenance fidelity across generations, resulting in a [~]1.5-fold increase in epimutation rates. Genotypes with elevated rates exhibited accelerated epigenetic drift and phenotypic divergence. Our findings support a punctuated-equilibrium model of mCG evolution, in which sudden disruptions to methylation homeostasis can destabilize epigenetic inheritance over longer time-scales.

genetics↗

bioRxiv2025

Characterization of neuronal ensembles in a model of dual reward conditioned place preference

Substance use disorder (SUD) is associated with maladaptive alterations in behavior. Drug-seeking behavior has been associated with neuronal ensembles, defined here as a small group of neurons exhibiting coordinated activity patterns, in the prelimbic prefrontal cortex (PL) and nucleus accumbens core (NAcore). Most SUD preclinical research focuses on the effects of single-reward exposure on the general population of neurons within the reward pathway, rather than on poly-reward exposure. Here, we seek to characterize and compare the ensembles linked to cocaine and chocolate using a within-subject approach. We used Ai14xFos2A-iCreER (c-Fos-TRAP2) transgenic mice to tag neuronal ensembles in a novel dual cocaine and chocolate conditioned place preference (CPP) model, where each chamber was associated with a different reward, either cocaine or chocolate. We found that, after successful dual conditioning and in the absence of the rewards, mice preferred cocaine over chocolate. Additionally, in mice exposed to both cocaine and chocolate, cortical and accumbal ensembles linked to each reward were comparable in size to reward ensembles in mice exposed only to one reward. However, reward-seeking ensembles were larger than ensembles tagged in homecage control mice across groups. We also found that ensemble size does not correlate with the level of reward seeking across single and dual CPP models. These results offer a new paradigm for studying drug-related neuronal ensembles in comparison to natural rewards in non-contingent behavioral models.

neuroscience↗

bioRxiv2025

DCPS modulates TDP-43 mediated neurodegeneration through P-body regulation

The proteinopathy of the RNA-binding protein TDP-43, characterized by nuclear clearance and cytoplasmic inclusion, is a hallmark of multiple neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS), frontotemporal dementia (FTD), and Alzheimers disease (AD). Through CRISPR interference (CRISPRi) screening in human neurons, we identified the decapping enzyme scavenger (DCPS) as a novel genetic modifier of TDP-43 loss-of-function (LOF)-mediated neurotoxicity. Our findings reveal that TDP-43 LOF leads to aberrant mRNA degradation, via disrupting the properties and function of processing bodies (P-bodies). TDP-43 interacts with P-body component proteins, potentially influencing their dynamic equilibrium and assembly into ribonucleoprotein (RNP) granules. Reducing DCPS restores P-body integrity and RNA turnover, ultimately improving neuronal survival. Overall, this study highlights a novel role of TDP-43 in RNA processing through P-body regulation and identifies DCPS as a potential therapeutic target for TDP-43 proteinopathy-related neurodegenerative diseases.

neuroscience↗

bioRxiv2025

Ultra-wide-field, deep, adaptive two-photon microscopy

Observing the activity patterns of large neural populations throughout the brain is essential for understanding brain function. However, capturing neural interactions across widely distributed brain regions from both superficial and deep cortical layers remains challenging with existing microscopy technologies. Here, we introduce a state-of-the-art two-photon microscopy system, ULTRA, capable of single-cell resolution imaging across an ultra-large field of view (FOV) exceeding 50 mm{superscript 2}, enabling deep and very wide field in vivo imaging. To demonstrate its capabilities, we conducted a series of experiments under multiple imaging conditions, successfully visualizing brain structures and neuronal activities spanning a spatial range of over 7 mm from superficial layers to depths of up to 900 m, while covering a volume of 45.24 mm3 in the mouse brain. This versatile imaging platform overcomes traditional spatial constraints, providing a powerful tool for comprehensive exploration of neuronal circuitry over extensive spatial scales with cellular resolution.

neuroscience↗

bioRxiv2025

Neuronal migration induces DNA damage in developing brain

Migratory cells tend to have soft nuclei that deform and penetrate narrow spaces1,2. Extensive nuclear deformation during migration can cause nuclear envelope rupture and DNA damage in cancer cells, which may contribute to the malignant transformation during tumor progression3,4,5,6. However, the significance of DNA damage in physiological migration is less well understood. Here, we demonstrate that the migration of neurons in developing cerebral and cerebellar cortices is accompanied by massive DNA double-strand breaks (DSBs) due to mechanostress during passage through narrow interstitial spaces. Confined migration enhances the binding and cleavage of the genome by topoisomerase II{beta}, expressed in neuronal nucleus, independently of the nuclear envelope rupture. Genome sequencing revealed that DSBs tend to occur outside of protein-coding regions and transcription regulatory regions. During normal development, DSBs are rapidly repaired by the non-homologous end joining pathway. The deletion of ligase IV at the onset of neuronal migration leads to persistent DSB accumulation in cerebellar neurons with moderate transcriptional changes in genes related to synaptic function, neuronal development, and stress and immune responses. The mutant mouse develops mild motor deficits in later life, suggesting that the DNA damage generated during normal brain development poses a potential disease risk if left unrepaired.

cell biology↗

bioRxiv2025

The Pathological Role and Therapeutic potential of ALDH2 in acrolein detoxification Following Spinal Cord Injury in Mice

Oxidative stress and lipid peroxidation-derived aldehydes, such as acrolein, play a central role in the pathology of spinal cord injury (SCI) and have emerged as promising therapeutic targets. Mitochondrial aldehyde dehydrogenase-2 (ALDH2) is a key oxidoreductase responsible for detoxifying reactive aldehydes. Pharmacological activation of ALDH2 using Alda-1, a selective agonist, has been shown to reduce aldehyde accumulation, alleviate inflammation, and enhance functional recovery in experimental SCI models. However, approximately 8% of the global population carries the ALDH2*2 mutation, which severely impairs this detoxification pathway. In this study, we used a transgenic ALDH2*2 mouse model to investigate the role of ALDH2 in SCI pathology. This model mimics the human ALDH2*2 condition, allowing us to examine the impact of impaired aldehyde clearance on acrolein accumulation and its pathological consequences. We modulated endogenous aldehyde detoxification through both genetic deficiency and pharmacological activation with Alda-1. Our results showed that ALDH2 deficiency led to significantly elevated acrolein levels, which were associated with increased microglial activation, cytokine storm, neuronal loss, demyelination, and tissue damage compared to wild-type (WT) mice. Treatment with Alda-1 enhanced ALDH2 activity and significantly reduced acrolein levels in both ALDH2*2 and WT mice from 2 to 28 days post-SCI. This was accompanied by reduced inflammation, improved preservation of myelin, and marked improvements in locomotor and sensory function, especially in ALDH2*2 mice. Notably, even beyond the traditionally ideal treatment window, Alda-1 treatment remained effective in promoting recovery, particularly in motor function and to a greater extent in ALDH2*2 mice. Our study comprehensively evaluated ALDH2s role in SCI by both genetically impairing and pharmacologically enhancing its activity, highlighting ALDH2 as a critical modulator of acrolein-mediated damage and suggesting its potential as a therapeutic target, especially for individuals with the ALDH2*2 mutation.

neuroscience↗

bioRxiv2025

Global profiling of the proteome and acetylome in mice with abdominal aortic aneurysms

BackgroundAbdominal Aortic Aneurysm (AAA) is a life-threatening vascular condition characterized by a progressive dilation of the abdominal aorta and a high risk of rupture. Currently, no effective pharmacological therapies are available, and treatment relies mainly on surgical intervention. The lack of drug targets is largely due to limited understanding of the molecular mechanisms underlying AAA development. This study aims to identify potential therapeutic targets by performing comprehensive proteomic and acetylomic analyses in a mouse model of AAA. MethodsWe conducted global proteomic and acetylomic profiling on abdominal aortic tissues collected from an AAA mouse model. A total of 7,858 proteins and 1,790 acetylated proteins encompassing 4,581 acetylation sites were quantified. Bioinformatics analyses were performed to investigate the regulatory networks and biological pathways associated with these proteins and post-translational modifications. ResultsIntegrated analysis revealed that histone-related proteins were significantly enriched in pathways co-regulated by the proteome and acetylome. These pathways are influenced by histone acetyltransferases and deacetylases, implicating histone acetylation in AAA-related inflammatory and immune processes. Notably, the deacetylases Sirt2 and Sirt5 were identified as potential regulators of neutrophil extracellular trap (NET) formation through suppression of histone acetylation. ConclusionsThis study provides the first comprehensive proteomic and acetylomic dataset for abdominal aortic tissues in a mouse model of AAA, substantially expanding the mouse acetylation database. The results highlight the central role of histone modifications in immune dysregulation and inflammation, and propose Sirt2 and Sirt5 as candidate therapeutic targets that may inhibit NET formation and slow AAA progression. These findings suggest new avenues for drug development targeting the sirtuin family, although further experimental validation and cross-species studies are needed to confirm translational relevance. Graphic Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=145 SRC="FIGDIR/small/657536v1_ufig1.gif" ALT="Figure 1"> View larger version (42K): org.highwire.dtl.DTLVardef@1c397a3org.highwire.dtl.DTLVardef@188180org.highwire.dtl.DTLVardef@de1a59org.highwire.dtl.DTLVardef@193e740_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioinformatics↗

bioRxiv2025

Gene therapies alleviate absence epilepsy associated with Scn2a deficiency in DBA/2J mice

Mutations in the voltage-gated sodium channel gene SCN2A, which encodes the NaV1.2 channel, cause severe epileptic seizures. Patients with SCN2A loss-of-function (LoF) mutations, such as protein-truncating mutations, often experience later-onset and drug-resistant epilepsy, highlighting an urgent unmet clinical need for new therapies. We previously developed a gene-trap Scn2a (Scn2agt/gt) mouse model with a global NaV1.2 reduction in the widely used C57BL/6N (B6) strain. Although these mice display multiple behavioral abnormalities, EEG recordings indicated only mild epileptiform discharges, possibly attributable to the seizure-resistant characteristics associated with the B6 strain. To enhance the epileptic phenotype, we derived congenic Scn2agt/gt mice in the seizure-susceptible DBA/2J (D2J) strain. Notably, we found that these mice exhibit prominent spontaneous absence seizures, marked by both short and long spike-wave discharges (SWDs). Restoring NaV1.2 expression in adult mice substantially reduced their SWDs, suggesting the possibility of SCN2A gene replacement therapy during adulthood. RNA sequencing revealed significant alterations in gene expression in the Scn2agt/gt mice, in particular a broad downregulation of voltage-gated potassium channel (KV) genes, including KV1.1. The reduction of KV1.1 expression was further validated in human cerebral organoids with SCN2A deficiency, highlighting KV1.1 as a promising therapeutic target for refractory seizures associated with SCN2A dysfunction. Importantly, delivery of exogenous human KV1.1 expression via adeno-associated virus (AAV) in D2J Scn2agt/gt mice substantially reduced absence seizures. Together, these findings underscore the influence of mouse strain on seizure severity and highlight the potential of targeted gene therapies for treating SCN2A deficiency-related epilepsies. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=91 SRC="FIGDIR/small/657652v1_ufig1.gif" ALT="Figure 1"> View larger version (18K): org.highwire.dtl.DTLVardef@35374eorg.highwire.dtl.DTLVardef@1c22197org.highwire.dtl.DTLVardef@2b4582org.highwire.dtl.DTLVardef@e06e68_HPS_FORMAT_FIGEXP M_FIG C_FIG In briefScn2a deficiency leads to absence seizures in D2J mice and neuronal hyperexcitability with compensatory KV reduction; restoring NaV1.2 or introducing human KV1.1 reduces seizure burden. HighlightsO_LIScn2a deficiency induces robust absence seizures in the DBA/2J but not the C57BL/6N strain. C_LIO_LICortical neurons in adult DBA/2J mice with Scn2a deficiency exhibit intrinsic hyperexcitability. C_LIO_LISevere Scn2a deficiency leads to downregulation of multiple potassium channel genes. C_LIO_LIGenetic restoration of NaV1.2 expression alleviates spike-wave discharges (SWDs). C_LIO_LIAAV-mediated human KV1.1 delivery substantially reduced absence seizures, demonstrating the therapeutic potential of targeted gene therapy. C_LI

neuroscience↗

bioRxiv2025

OriGene: A Self-Evolving Virtual Disease Biologist Automating Therapeutic Target Discovery

Here, we present OriGene, a self-evolving multi-agent system that functions as a virtual disease biologist, systematically identifying original and mechanistically grounded therapeutic targets at scale. OriGenes architecture integrates over 600 specialized tools through a Model Context Protocol (MCP), enabling it to reason across diverse data modalities including genomics, protein networks, pharmacology, clinical records and literature evidence, to generate and prioritize target discovery hypotheses. We implemented a strategy combining a knowledge graph-based Tool RAG with an advanced agent selection mechanism to enable dynamic, context-aware tool deployment. Through a self-evolving framework, OriGene continuously integrates human and experimental feedback to iteratively refine its core thinking templates, tool composition, and analytical protocols, thereby enhancing both accuracy and adaptability over time. To comprehensively evaluate its performance, we established TRQA, an original benchmark comprising over 1,900 expert-level question-answer pairs spanning a wide range of diseases and target classes. OriGene consistently outperforms human experts, leading research agents, and state-of-the-art large language models in accuracy, recall, and robustness, particularly under conditions of data sparsity or noise. Critically, OriGene nominated previously underexplored therapeutic targets for liver (GPR160) and colorectal cancer (ARG2), which demonstrated significant anti-tumor activity in patient-derived organoid and tumor fragment models mirroring human clinical exposures. These findings demonstrate OriGenes potential as a scalable and adaptive platform for AI-driven discovery of mechanistically grounded therapeutic targets, offering a new paradigm to accelerate drug development.

bioinformatics↗

bioRxiv2025

Assembly and phospho-regulatory mechanisms of the budding yeast outer kinetochore KMN complex

During mitosis and meiosis kinetochores mediate interactions between chromosomes and spindle microtubules. Kinetochores are multi-megadalton protein complexes essential for chromosome segregation in all eukaryotes, however recent structural, functional, and evolutionary studies have revealed divergent mechanisms of kinetochore assembly. In this study, we use cryo-EM to understand the structural mechanisms by which the budding yeast microtubule-binding outer kinetochore KMN complex assembles, and how its interactions with the centromere-binding inner kinetochore are regulated. The ten-subunit KMN complex comprises three subcomplexes: Knl1c, Mis12cMtw1c and Ndc80c. We show that -helical motifs in the C-termini of the Mis12cMtw1c subunits Dsn1, Mis12Mtw1 and Nnf1 bind Knl1c and Ndc80c. At the opposite end of the Mis12cMtw1c stalk, an N-terminal auto-inhibitory segment of Dsn1 (Dsn1AI) folds into two -helices that engage the Mis12cMtw1c head 1 domain, thereby occluding binding sites for the inner kinetochore subunits CENP-CMif2 and CENP-UAme1, reducing their affinity for Mis12cMtw1. Our structure reveals how Aurora BIpl1 phosphorylation of Dsn1AI would release this auto-inhibition to substantially strengthen pre-existing connections between the inner and outer kinetochore. SummaryKinetochore-localised KMN complexes mediate chromosome segregation by attaching chromosomes to spindle microtubules. Cryo-EM, biochemical and genetic experiments reveal conserved underlying mechanisms of complex assembly, auto-inhibition and phospho-regulation that ensure precise control of KMN assembly onto centromeres to enable genome division.

biochemistry↗

bioRxiv2025

Dendritic computation for rule-based flexible categorization

A hallmark of intelligent behavior is the ability to flexibly respond to external sensory inputs based on dynamically changing rules. A central question is how neurons in the brain implement computations underlying intelligent behaviors. The neocortical pyramidal neurons use their elaborated dendritic arbors to segregate a plethora of inputs and dynamically integrate them--a process known as dendritic computation--which may play important roles in rule-dependent sensory processing. However, evidence directly linking dendritic computation with intelligent cognitive behaviors has been absent. Here we combine two-photon imaging and a rule-switching flexible categorization task in mice to show that a projectome-defined extratelencephalic (ET) cortical layer 5 (L5) neurons in the auditory cortex integrate dendritic rule information and somatic sensory input to enable rule-dependent flexible categorization. The apical dendrite and soma within the same ET neurons exhibit distinct compartmental representations for sensory and rule information, with the soma predominantly encoding sensory information and the dendrites representing inferred task rule. Simultaneous optogenetic dendritic inhibition and two-photon imaging revealed that dendritic rule coding is essential for somatic output of flexible categorization. Our findings indicate that nonlinear dendritic integration of rule and sensory information constitutes a neuronal computational mechanism underlying rule-switching flexible decision-making.

neuroscience↗

bioRxiv2025

Autism-associated SCN2A deficiency disrupts cortico-striatal circuitry in human brain assembloids

Profound autism spectrum disorder (ASD) is frequently attributable to single-gene mutations, with SCN2A (voltage-gated sodium channel NaV1.2) protein-truncating variants (PTVs) being one of the most penetrant. Although cortico-striatal circuitry is implicated as a key node in ASD, the impact of SCN2A deficiency on human neural circuits is unknown. Using the human cortico-striatal assembloid model, we show that the autism-causing PTV SCN2A-C959X impairs long-range cortical axonal projections, reduces striatal spine density, and attenuates excitatory cortical-striatal synaptic transmission. Surprisingly, these assembloids carrying the heterozygous SCN2A nonsense mutation exhibited pronounced network hyperexcitability, a human cell-specific phenotype not observed in Scn2a+/- mice, highlighting a human-specific circuit vulnerability. Collectively, our study unveils human circuit-specific dysfunctions of SCN2A deficiency and SCN2A-mediated ASD. HighlightsO_LIAxonal projections facilitate synapse formation and functional connectivity in human brain assembloids. C_LIO_LINaV1.2 is expressed along neuronal axons, extending to soma and dendrites in human brain assembloids. C_LIO_LISCN2A-C959X disrupts axonal projection patterns, impairs excitatory synaptic transmission, reduces spine density, and results in elevated neuronal excitability. C_LI Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=90 SRC="FIGDIR/small/657036v1_ufig1.gif" ALT="Figure 1"> View larger version (27K): org.highwire.dtl.DTLVardef@6d5b1forg.highwire.dtl.DTLVardef@1795ecdorg.highwire.dtl.DTLVardef@13f0d7eorg.highwire.dtl.DTLVardef@8ee059_HPS_FORMAT_FIGEXP M_FIG C_FIG In briefO_ST_ABSSCN2A haploinsufficiency impairs cortico-striatal circuitry.C_ST_ABSSCN2A haploinsufficiency disrupts axon initial segment (AIS) integrity, leading to hyperexcitability (red arrow), reduced axon projections, and impaired synaptic transmission (decreased sEPSCs and altered network firing). These deficits result in dysfunction within the cortico-striatal circuitry.

neuroscience↗