Biology subjects

Miyashita, S.

Publications and source records attributed to Miyashita, S..

17 recordsLinked to original sources

bioRxiv2026

Spatial transcriptomics identifies L6 corticothalamic and L6b subplate-like heterotopic neurons in an epileptogenic SLC35A2-associated brain malformation.

Increased white matter (WM) heterotopic neurons are a pathological feature observed in various neurological and psychiatric disorders. Mild malformation of cortical development with oligodendroglial hyperplasia in epilepsy (MOGHE) is a drug-resistant epilepsy-associated cortical malformation characterized by increased WM heterotopic neurons and OLIG2-positive cells and frequently associated with somatic SLC35A2 mutations. However, the precise cellular identity of these heterotopic neurons remains unclear. Using imaging-based spatial transcriptomics (iST) of SLC35A2-mutated MOGHE tissues, we found that most WM heterotopic neurons exhibited molecular signatures of excitatory neurons. Further analyses revealed that these heterotopic excitatory neurons included prominent populations with layer 6 corticothalamic (CT)-like and layer 6b subplate neuron (SpN)-like molecular features. These findings were further supported by human immunohistochemistry and a Slc35a2 conditional knockout (cKO) mouse model. Together, our results provide a cellular characterization of WM heterotopic neurons in MOGHE and suggest a new perspective on disease pathophysiology centered on deep-layer excitatory neuronal populations.

neuroscience↗

bioRxiv2026

STING restrains calcium-dependent microglial phagocytosis and protects against neuronal loss and cognitive impairment during epileptogenesis

Epileptogenesis is accompanied by robust neuroinflammation, yet the molecular pathways linking innate immune activation to neuronal dysfunction remain incompletely defined. Given the established pro-inflammatory role of the stimulator of interferon genes (STING), we initially hypothesized that its loss would attenuate neuroinflammatory responses during epileptogenesis. Contrary to our expectation, we found that STING deficiency instead amplified microglial activation. Using a kainic acid mouse model of temporal lobe epilepsy (TLE), we show that STING-deficient microglia exhibit pronounced lysosomal expansion and enhanced phagocytic engulfment of neurons, leading to increased hippocampal neuronal loss and cognitive impairment. Mechanistically, STING deficiency increased the expression and altered the subcellular distribution of stromal interaction molecule 1 (STIM1), an endoplasmic reticulum Ca{superscript 2} sensor that mediates store-operated calcium entry (SOCE), resulting in dysregulated intracellular calcium dynamics and elevated SOCE activity. Pharmacological inhibition of SOCE reduced microglia-neuron interactions and microglial phagocytic engulfment, improved neuronal survival in the CA3 region of the hippocampus, and rescued cognitive deficits following status epilepticus. Collectively, these findings redefine STING as a negative regulator of microglial activation and identify a previously unrecognized STING-STIM1-SOCE axis that constrains calcium-dependent microglial phagocytosis during epileptogenesis, highlighting microglial calcium signaling as a potential therapeutic target in TLE.

neuroscience↗

bioRxiv2026

A Stronger Association Between Screen Time and Externalizing Problems in Typically Developing Children than in Children with Autism Spectrum Disorder

Excessive screen use is associated with childhood behavioral problems, but whether associations differ between typically developing (TD) children and those with autism spectrum disorder (ASD) is unclear. Our cross-sectional study included 108 children aged 5-9 years (61 TD, 47 ASD). ASD was diagnosed using standardized clinical instruments. Measures included parent-reported screen time (excluding TV/DVD), cognitive ability (K-ABC), and behavioral problems (Vineland-II). Screen time and externalizing problems were associated in the TD group (Spearmans {rho} = 0.361, p < 0.01), but not in the ASD group. In the regression model, screen time ({beta} = 0.40, t = 2.60, p < 0.05), ASD status ({beta} = 0.70, t = 8.30, p < 0.001), and their interaction ({beta} = -0.34, t = -2.06, p < 0.05) significantly predicted externalizing problems. Considering the diversity within the autism spectrum, future studies with larger sample sizes should consider individual heterogeneity when examining the association between behavioral outcomes and screen time.

scientific communication and education↗

bioRxiv2026

Comprehensive transcriptomic and proteomic profiling of mTOR-related epilepsy

Malformations of cortical development (MCDs) are a major cause of drug-resistant epilepsy (DRE) in children. A subset of MCDs, including focal cortical dysplasia type II, tuberous sclerosis complex, and hemimegalencephaly, shares characteristic histopathological features and somatic mutations in genes within the PI3K-AKT-mTOR signaling cascade, and is termed mTORopathies. However, the molecular mechanisms that drive epileptogenesis and consequent uncontrollable seizures in these disorders remain poorly understood. Here, we performed integrated genomic, transcriptomic, and proteomic analyses of 60 surgical brain specimens from 42 patients with MCDs and 18 with mesial temporal lobe epilepsy. Targeted genomic sequencing identified 19 somatic mutations in PI3K-AKT-mTOR pathway genes, including novel variants in AKT3 (L51H) and MTOR (A512T). RNA sequencing comparing mTORopathy brains with controls, along with cross-validation using an independent public dataset, identified 287 consistently differentially expressed genes that were consistently altered. Downregulated genes were enriched in oxidative phosphorylation (OXPHOS) and mitochondrial metabolic pathways, whereas upregulated genes were associated with gliogenesis and cellular senescence. Proteomic profiling identified 44 differentially expressed proteins, including significant reductions in OXPHOS-related proteins (COX5B, NDUFS4, GOT2, RAB27B, and DKK3). Our study provides a patient-matched, multi-omics dataset of human mTOR-related epilepsies from a single-institution cohort. Integrated analyses across transcriptomic and proteomic layers highlight impairment of OXPHOS as a molecular hallmark of mTORopathies, Integrated transcriptomic and proteomic analyses identified impaired OXPHOS as a molecular hallmark, potentially contributing to focal hypometabolism in mTORopathy. These findings offer mechanistic insights into epileptogenesis and provide a valuable resource for understanding molecular pathologies and developing mechanism-based therapies for mTOR-related epilepsy.

neuroscience↗

bioRxiv2026

Single-cell-resolved spatial multi-omics identifies mTOR-driven neuronal and astroglial pathogenicity underlying epileptogenic focal cortical dysplasia

Focal cortical dysplasia type II (FCDII) is a malformation of cortical development caused by somatic mutations in the mTOR signaling pathway. Two hallmark pathological cell types in FCDII, dysmorphic neurons (DNs) and balloon cells (BCs), arise as a result of somatic mutations in the mTOR signaling pathway and are implicated in the pathophysiology of drug-resistant epilepsy. However, how these somatic mutations reshape cell states within the human cortex remains poorly understood. Here, we integrate imaging-based spatial transcriptomics (iST), single-nucleus RNA sequencing, and proteomics of surgically resected FCDIIb tissue to define the transcriptional and proteomic profiles of DNs and BCs. Spatial mapping of iST data resolved transcriptional signatures in histologically validated DNs and BCs within FCDIIb sections. Integrative omics analysis further revealed that DNs show upregulation of PI3K-AKT-mTOR and p53-CROT metabolic programs accompanied by suppression of synaptic signaling, whereas BCs exhibit transcriptional signatures of reactive astrocytes with increased phagocytic and immune-like activity. These data delineate cell-type-specific consequences of somatic mTOR pathway mutations at single-cell resolution and reveal previously unrecognized metabolic and immunoregulatory mechanisms contributing to epileptogenesis in drug-resistant epilepsy. Our study establishes a spatial multi-omics framework for dissecting human cortical malformations and highlights potential therapeutic targets for drug-resistant epilepsy.

neuroscience↗

bioRxiv2026

MEIS1 is Required for Establishing Bergmann Glia-Specific Properties in the Developing Cerebellum

Compared to normal multipolar astrocytes, Bergmann glial cells (BGs), specifically differentiated astrocytes in the cerebellum, possess unique unipolar morphology and additional cellular functions. However, the molecular mechanisms that confer BG-specific properties onto normal multipolar astrocytes remain unknown. Here, we show that the transcription factor, MEIS1, is involved in BGs acquiring their unique characteristics. Targeted disruption of Meis1 in the whole cerebellum or astroglial lineage cells resulted in a marked reduction of BGs accompanied by an increase in multipolar astrocytes in mice. Postnatal deletion of Meis1 in Bergmann glia-like progenitors (BGLPs), which produce both BGs and multipolar astrocytes, suppressed their differentiation into BGs while promoting into multipolar astrocytes. Single-cell RNA sequencing, immunohistochemistry, and ChIP-Atlas analyses indicated that MEIS1 directly upregulates expression of BG-specific genes, including Vimentin and Zeb2, which are known to contribute to the correct localization and the unipolar process formation of BGs. These findings suggest that MEIS1 promotes the endowment of BG-specific properties to astrocytes by controlling the expression of BG-specific genes, thereby ensuring proper differentiation of BGLPs into BGs.

developmental biology↗

bioRxiv2025

Dormant viral pathways underlie space-induced neural senescence: a neuroprotective strategy for spaceflight and neurological diseases

Long-duration spaceflight is associated with neurological symptoms in astronauts, yet the underlying molecular mechanisms remain unclear. Using human brain organoids cultured aboard the International Space Station, we analyzed three independent spaceflights to demonstrate that exposure to the space environment triggers Space-Induced Neural Senescence (SINS), characterized by chromatin remodeling, mitochondrial dysfunction, and activation of viral-like transcriptional programs in the absence of infection. Multi-omics analyses identified upregulation of endogenous LINE-1 (L1) retroelements, whose activity was markedly enhanced in organoids lacking MECP2, a known L1 repressor implicated in Rett syndrome. The resulting accumulation of cytoplasmic L1 DNA elicited an IL-6-mediated inflammatory and neurotoxic response, which was reversed by reverse transcriptase inhibitors (RTi) such as lamivudine or stavudine. Parallel preclinical experiments in Mecp2-deficient mice confirmed that RTi treatment restored neuronal morphology, synaptogenesis, function, cognition, and survival. These findings reveal that the space environment reactivates dormant genomic retroelements, providing an unexpected mechanistic insight into astronaut neurobiology and identifying a potential therapeutic strategy for both space-induced and terrestrial neurological conditions. Our pioneering study demonstrates the value of space-enabling research in accelerating drug discovery and disease treatment on Earth.

neuroscience↗

bioRxiv2025

Lineage Analysis and Molecular Characterization of Bergmann Glia-like Progenitors in the Postnatal Mouse Cerebellum using in vivo Electroporation and Spatial Transcriptomics

In the mammalian cerebellum, three types of astroglial cells--Bergmann glial cells (BGs), inner granule cell layer (IGL) astrocytes, and white matter (WM) astrocytes--arise in postnatal timing from two types of progenitors: Bergmann glia-like progenitors (BGLPs) and astrocyte-like progenitors (AsLPs). In contrast to AsLPs, which are commonly observed in other brain regions, BGLPs have not been well studied. Here we investigate their dynamic changes in number, their differentiation abilities and their gene expression profiles during cerebellar development. BGLPs and AsLPs decrease in number as development progresses from P0, and are almost absent by P10. We developed an electroporation-based method to investigate the progeny cells of BGLPs. We found that BGLPs at P6 differentiate into BGs and IGL astrocytes, but not into WM astrocytes, which is consistent with a previous report. However, BGLPs at P0 were observed to differentiate into not only BGs and IGL astrocytes, but also WM astrocytes, indicating that P0 BGLPs possess wider pluripotency than P6 BGLPs. By conducting spatial transcriptomic analysis of the cerebellum at P0 and P6 with over 5,000 probes (Xenium, 5k), we successfully obtained clusters corresponding to BGLPs at P0 and P6, respectively. Further informatics analyses suggested that P0 BGLPs exhibit more stem cell-like features, while P6 BGLPs show a shift toward BG-like characteristics. This study, which includes transcriptome big data, will contribute to understanding the differentiation of BGs and astrocytes, as well as other types of cells, during postnatal cerebellar development.

developmental biology↗

bioRxiv2024

AUTS2, a causative gene for microcephaly, regulates division of intermediate progenitor cells and production of upper-layer neurons

AUTS2 mutations often exhibit neurodevelopmental disorders and microcephaly. However, how AUTS2 regulates neuron production and affects brain size remains unclear. Here, we show that AUTS2 cooperates with the Polycomb complex PRC2 to regulate gene expression and cortical neurogenesis. Auts2 mutant mice exhibit reduced division of intermediate progenitor cells (IPCs), leading to decreased neurons and thickness in the upper-layer cortex. Expression of Robo1 is increased in the mutants, which in turn suppresses IPC division. Transcriptome and chromatin profiling experiments show that, in IPCs, AUTS2 primarily represses transcription of genes, including Robo1. Promoter region of AUTS2 target genes is enriched with H3K27me3, a repressive histone modification, but its levels are reduced in Auts2 mutants. AUTS2 interacts with PRC2, and together, they promote IPC division. These suggest that AUTS2 collaborates with PRC2 to repress gene transcription through H3K27 trimethylation, promoting neuron production. This sheds light on AUTS2 pathophysiological mechanisms in neurogenesis and microcephaly.

neuroscience↗

bioRxiv2023

Kinesin family member Kif23 regulates cytokinetic division and maintains neural stem/progenitor cell pool in the developing neocortex

Accurate mitotic division of neural stem cell/progenitor cells (NSPCs) is crucial for the coordinated generation of progenitors and neurons in the developing cortex. Here, we investigated the pivotal role of Kif23, an N-kinesin motor protein, in embryonic mouse NSPCs. We found that Kif23 is highly expressed in the mitotic NSPCs within the embryonic cortex of both mouse and human. Knockdown (KD) of Kif23 led to precocious neurogenesis, attributed to an accelerated cell cycle exit, likely resulting from disrupted mitotic spindle orientation and impaired cytokinesis. Kif23 KD induced upregulation of the {gamma}-H2AX-p53-p21 signaling pathway, ultimately culminating in cytokinetic failure. Additionally, Kif23 depletion perturbed the apical surface structure of NSPCs and disrupted the proper localization of apical junctional proteins. Importantly, we demonstrated the successful rescue of Kif23 KD-induced phenotypes by introducing wild-type human KIF23, but not by a variant of KIF23 with a microcephaly-associated mutation. Our findings underscore the critical role of Kif23 in cortical development and provide novel insights into the intricate molecular mechanisms underlying pathogenesis of microcephaly. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=88 SRC="FIGDIR/small/564302v1_ufig1.gif" ALT="Figure 1"> View larger version (33K): org.highwire.dtl.DTLVardef@5488e0org.highwire.dtl.DTLVardef@1e65146org.highwire.dtl.DTLVardef@1e1ec76org.highwire.dtl.DTLVardef@16b7477_HPS_FORMAT_FIGEXP M_FIG C_FIG

developmental biology↗

bioRxiv2023

Single-cell mutation rate of turnip crinkle virus (-)-strand replication intermediates

Viruses with single-stranded, positive-sense (+) RNA genomes incur high numbers of errors during replication, thereby creating diversified genome populations from which new, better adapted viral variants can emerge. However, a definitive error rate is known for a relatively few (+) RNA plant viruses, due to challenges to account for perturbations caused by natural selection and/or experimental set-ups. To address these challenges, we developed a new approach that exclusively profiled errors in the (-)-strand replication intermediates of turnip crinkle virus (TCV), in singly infected cells. A series of controls and safeguards were devised to ensure errors inherent to the experimental process were accounted for. This approach permitted the estimation of a TCV error rate of 8.47 X 10-5 substitution per nucleotide site per cell infection. Importantly, the characteristic error distribution pattern among the 50 copies of 2,363-base-pair cDNA fragments predicted that nearly all TCV (-) strands were products of one replication cycle per cell. Furthermore, some of the errors probably elevated error frequencies by lowering the fidelity of TCV RNA-dependent RNA polymerase, and/or permitting occasional re-replication of progeny genomes. In summary, by profiling errors in TCV (-)-strand intermediates incurred during replication in single cells, this study provided strong support for a stamping machine mode of replication employed by a (+) RNA virus. Author SummaryMost (+) RNA viruses introduce replication errors at relatively high frequencies. As a result, it is of vital importance for these viruses to purge lethal errors in a timely manner. TCV, a plant-infecting small (+) RNA virus, was proposed to encode a Bottleneck, Isolate, Amplify, Select (BIAS) mechanism that compel swift clearance of lethal errors by bottlenecking the number of replicating genome copies to one per cell. A crucial prediction of this BIAS model is that such bottlenecking also acts on progeny genome copies, preventing them from repeating replication in the cells of their own genesis. The current study tested this prediction by developing a carefully controlled, readily reproducible approach to profile errors and error distributions in (-)-stranded replication intermediates of TCV. We found that most of replication-generated (-) strands descended from the primary (+) strands through a single replication cycle. This finding adds fresh support to the BIAS model.

evolutionary biology↗

bioRxiv2022

Cerebrospinal fluid-contacting neuron tracing reveals structural and functional connectivity for locomotion in the mouse spinal cord

Cerebrospinal fluid-contacting neurons (CSF-cNs) are enigmatic mechano- or chemosensory cells lying along the central canal of the spinal cord. Recent studies in zebrafish larvae and lampreys have shown that CSF-cNs control postures and movements via spinal connections. However, the structures, connectivity, and functions in mammals remain largely unknown. Here we developed a method to genetically target mouse CSF-cNs that highlighted structural connections and functions. We first found that intracerebroventricular injection of adeno-associated virus with a neuron-specific promoter and Pkd2l1-Cre mice specifically labeled CSF-cNs. Single-cell labeling of 71 CSF-cNs revealed rostral axon extensions of over 1800 m in unmyelinated bundles in the ventral funiculus and terminated on CSF-cNs to form a recurrent circuitry, which was further determined by serial electron microscopy and electrophysiology. CSF-cNs were also found to connect with axial motor neurons and premotor interneurons around the central canal and within the axon bundles. Chemogenetic CSF-cNs inactivation reduced speed and step frequency during treadmill locomotion. Our data revealed the basic structures and connections of mouse CSF-cNs to control spinal motor circuits for proper locomotion. The versatile methods developed in this study will contribute to further understanding of CSF-cNs functions in mammals.

neuroscience↗

bioRxiv2022

Brain Atlas for Glycoprotein Hormone Receptors at Single-Transcript Level

There is increasing evidence that anterior pituitary hormones, traditionally thought to have unitary functions in regulating single endocrine targets, act on multiple somatic tissues, such as bone, fat, and liver. There is also emerging evidence for anterior pituitary hormone action on brain receptors in mediating central neural and peripheral somatic functions. Here, we have created the most comprehensive neuroanatomical atlas on the expression of TSHRs, LHCGRs and FSHRs. We have used RNAscope, a technology that allows the detection of mRNA at single-transcript level, together with protein level validation, to document Tshr expression in 173 and Fshr expression in 353 brain regions, nuclei and sub-nuclei identified using the Atlas for the Mouse Brain in Stereotaxic Coordinates. We also identified Lhcgr transcripts in 401 brain regions, nuclei and sub-nuclei. Complementarily, we used ViewRNA, another single-transcript detection technology, to establish the expression of FSHRs in human brain samples, where transcripts were co-localized in MALAT1-positive neurons. In addition, we show high expression for all three receptors in the ventricular region--with yet unknown functions. Intriguingly, Tshr and Fshr expression in the ependymal layer of the third ventricle was similar to that of the thyroid follicular cells and testicular Sertoli cells, respectively. TSHRs were expressed specifically in tanycytes. In contrast, Fshrs were localized to NeuN-positive neurons in the granular layer of the dentate gyrus in murine and human brain--both are Alzheimers disease vulnerable regions. Our atlas thus provides a vital resource for scientists to explore the link between the stimulation or inactivation of brain glycoprotein hormone receptors on somatic function. New actionable pathways for human disease may be unmasked through further studies.

neuroscience↗

bioRxiv2022

A small DNA virus initiates replication with no more than three genome copies per cell

Cellular organisms purge lethal mutations as they occur (in haploids), or as soon as they become homozygous (in sexually reproducing diploids), thus making the mutation-carrying genomes the sole victims of lethality. How lethal mutations in viruses are purged remains an unresolved question because numerous viral genomes could potentially replicate in the same cell, sharing their encoded proteins, hence shielding lethal mutations from selection. Previous investigations by us and others suggest that viruses with plus strand (+) RNA genomes may compel such selection by bottlenecking the replicating genome copies in each cell to low single digits. However, it is unclear if similar bottlenecks also occur in cells invaded by DNA viruses. Here we investigated whether tomato yellow leaf curl virus (TYLCV), a small virus with a single-stranded DNA genome, underwent population bottlenecking in cells of its host plants. We engineered the TYLCV genome to produce two replicons that express green fluorescent protein and mCherry, respectively, in a replication-dependent manner. We found that less than 65% of cells penetrated by both replicons replicated both, whereas at least 35% of cells replicated either of them alone, illustrating an intracellular population bottleneck size of no more than three. Furthermore, sequential inoculations unveiled strong mutual exclusions of these two replicons in most cells. Collectively our data demonstrated for the first time that DNA viruses like TYLCV are subject to stringent intracellular population bottlenecks, suggesting that such population bottlenecks may be a virus-encoded, evolutionarily conserved trait that assures timely elimination of lethal mutations. Significance statementAn important unresolved issue in virus life cycles is how natural selection acts on individual virus copies in the same cells. Unlike cellular organisms in which genome copies with lethal or advantageous mutations usually share their hosts with no more than one homologous genome copy, viruses could potentially reproduce with numerous sister genomes per cell, permitting sharing of protein products, thereby greatly diminishing phenotypic impacts of otherwise eventful mutations. Previous investigations suggest that (+) RNA viruses solve this problem by bottlenecking the number of replicating genome copies to low single digits. The current study reveals strikingly similar intracellular population bottlenecks for a DNA virus. Further mechanistic interrogations could avail the virus-encoded bottleneck-enforcing apparatus as targets for antiviral therapy and prevention.

microbiology↗

bioRxiv2022

A Single Multipurpose FSH-Blocking Therapeutic for Osteoporosis and Obesity

Pharmacological and genetic studies over the past decade have established FSH as an actionable target for diseases affecting millions, notably osteoporosis, obesity and Alzheimers disease (AD). Blocking FSH action prevents bone loss, fat gain and AD-like features in mice. We recently developed a first-in-class, humanized, epitope-specific FSH blocking antibody, MS-Hu6, with a KD of 7.52 nM. Using a GLP-compliant platform, we now report the efficacy of MS-Hu6 in preventing obesity and osteoporosis in mice, and parameters of acute safety in monkeys. Biodistribution studies using 89Zr-labelled, biotinylated or unconjugated MS-Hu6 in mice and monkeys showed localization to bone, bone marrow and fat depots. MS-Hu6 displayed a {beta} phase t[1/2] of 13 days (316 hours) in humanized Tg32 mice, and bound endogenous FSH. We tested 215 variations of excipients using the protein thermal shift assay to generate a final formulation that rendered MS-Hu6 stable in solution upon freeze-thaw and at different temperatures, with minimal aggregation, and without self-, cross-, or hydrophobic interactions or appreciable binding to relevant human antigens. MS-Hu6 showed the same level of "humanness" as human IgG1 in silico, and was non-immunogenic in ELISPOT assays for IL-2 and IFN{gamma} in human peripheral blood mononuclear cell cultures. We conclude that MS-Hu6 is efficacious, durable and manufacturable, and is therefore poised for future human testing as a multipurpose therapeutic.

pharmacology and toxicology↗

bioRxiv2020

CyclinD1 controls development of cerebellar granule cell progenitors through phosphorylation and stabilization of ATOH1

Here we report that CyclinD1 (CCND1) directly regulates both the proliferative and immature states of cerebellar granule cell progenitors (GCPs). CCND1 not only accelerates cell cycle but also upregulates ATOH1 protein, an essential transcription factor that maintains GCPs in an immature state. In cooperation with CDK4, CCND1 directly phosphorylates Ser309 of ATOH1, which inhibits additional phosphorylation at S328, consequently preventing Ser328 phosphorylation-dependent ATOH1 degradation. PROX1 downregulates Ccnd1 expression by histone-deacetylation of Ccnd1 promoter in GCPs, leading to cell cycle exit and differentiation. WNT signaling upregulates PROX1 expression in GCPs. These findings suggest that WNT-PROX1-CCND1-ATOH1 signaling cascade cooperatively controls proliferation and immaturity of GCPs. We revealed that the expression and phosphorylation levels of these molecules dynamically change during cerebellar development, which was suggested to determine appropriate differentiation rates from GCPs to GCs at distinct developmental stages. This study contributes to understanding the regulatory mechanism of GCPs as well as neural progenitors.

developmental biology↗

bioRxiv2019

AUTS2 regulation of synapses for proper synaptic inputs and social communication.

Impairments in synapse development are thought to cause numerous psychiatric disorders. Autism susceptibility candidate 2 (AUTS2) gene has been associated with various psychiatric disorders, such as autism and intellectual disabilities. Although roles for AUTS2 in neuronal migration and neuritogenesis have been reported, its involvement in synapse regulation remains unclear. In this study, we found that excitatory synapses were specifically increased in the Auts2-deficient primary cultured neurons as well as Auts2 mutant forebrains. Electrophysiological recordings and immunostaining showed increases in excitatory synaptic inputs as well as c-fos expression in Auts2 mutant brains, suggesting that an altered balance of excitatory and inhibitory inputs enhances brain excitability. Auts2 mutant mice exhibited autistic-like behaviors including impairments in social interaction and altered vocal communication. Together, these findings suggest that AUTS2 regulates excitatory synapse number to coordinate E/I balance in the brain, whose impairment may underlie the pathology of psychiatric disorders in individuals with AUTS2 mutations.

neuroscience↗