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Hagihara, M.

Publications and source records attributed to Hagihara, M..

At least 19 recordsLinked to original sources

A single-nucleus and spatial transcriptomic atlas of the Syrian hamster preoptic area across hibernation states

Hibernation is an extreme physiological state in certain mammals that is characterized by a reversible reduction in metabolic and thermogenic demands. Although the preoptic area has been implicated in the regulation of hibernation, comprehensive molecular and spatial resources for this brain region in hibernating mammals remain limited. Here, we present an integrated transcriptomic resource of the preoptic area generated using single-nucleus RNA sequencing (snRNA-seq) and Xenium-based spatial transcriptomics in a mammalian hibernator, Syrian hamster. The resource includes cross-species transcriptomic annotations relative to mouse preoptic area datasets, seasonal snRNA-seq datasets obtained under non-hibernating and hibernating conditions, and spatially resolved cell-type annotations generated from Xenium profiling. Together, these datasets provide a reference framework for identifying neuronal populations, examining molecular conservation across species and conditions, and integrating transcriptomic identity with spatial organization.

neuroscience↗

Hypothermic Conditions Impair GnRH Pulse Generator Activity and Gametogenesis

Mammalian reproductive function is driven by arcuate kisspeptin neurons, pacemakers of gonadotropin secretion. During energy shortages, animals reallocate resources from reproduction to survival; however, the underlying neural mechanisms remain elusive. Here we used fiber photometry to chronically monitor synchronized episodes of arcuate kisspeptin neuron activity (SEskiss) in adult mice under various energy-saving conditions. In both sexes, SEskiss frequency was markedly suppressed during fasting-induced torpor and pharmacologically induced hypothermia, whereas hypometabolism alone had no discernible effect. A Q neuron-induced hypothermic state (QIH) robustly suppressed SEskiss, leading to impaired gamete maturation, whereas warming the body temperature during QIH fully restored SEskiss frequency. These findings demonstrate that hypothermia, rather than hypometabolism, is the primary driver of suppression of the hypothalamic reproductive axis during energy-saving conditions. This study provides insights into how thermal signals act as critical gatekeepers in the mammalian reproductive system.

neuroscience↗

Pretraining Objective Shapes Cross-Category Generalization in Affective Image Prediction: A Geometric Comparison of Vision Transformer Encoders

The geometry of representations learned by deep neural networks is shaped jointly by architecture and pretraining objective, yet disentangling these two factors remains difficult. Here we isolate the contribution of pretraining objective by comparing two Vision Transformers from the same backbone family but trained under different objectives: language-image contrastive learning (CLIP) and ImageNet-21k classification. Using continuous Valence-Arousal prediction on the OASIS dataset as a probe of representational quality, we evaluated frozen features under Leave-One-Theme-Out and Leave-One-Category-Out cross-validation, the latter requiring extrapolation to entirely unseen semantic categories. The contrastively pretrained encoder generalized substantially better than the classification-pretrained encoder under both protocols, with the gap widening sharply when held-out categories required cross-category generalization. To characterize why the two representations differ, we developed a geometric analysis of prediction errors, treating per-image errors as vectors in the affective plane and quantifying their spatial structure via weighted phase-locking, trajectory-based occupancy entropy, and effective dimensionality. The classification-pretrained representation collapsed errors into a small number of attractor regions with a strong center-ward pull, whereas the language-aligned representation distributed errors broadly across the affective space. Layer-wise linear probing further revealed that affective information was distributed across depth in the contrastive encoder but increasingly concentrated in deeper layers of the classification encoder, mirroring the texture-bias and category-anchored statistics characteristic of ImageNet-trained representations. These results provide a representation-geometric account of how the choice of pretraining objective, holding architecture constant, determines whether learned features generalize across semantic boundaries or remain confined to category-bound visual regularities. HighlightsO_LIIsolate the effect of pretraining objective by holding the Vision Transformer backbone constant. C_LIO_LIContrastively pretrained features generalize across unseen semantic categories where classification-pretrained features fail. C_LIO_LIIntroduce a geometric analysis of prediction errors based on phase-locking and occupancy entropy. C_LIO_LIClassification pretraining produces concentrated error attractors and a rigid centerward bias. C_LIO_LIAffective information is distributed across depth in CLIP but localized in late layers of the classification ViT. C_LI

neuroscience↗

Transcriptomic Landscape of Microglia in Mouse Models of Social Dysfunction and Oxytocin-Mediated Recovery

Atypical sociability is a hallmark of neurodevelopmental disorders arising from genetic susceptibility and prenatal environmental perturbations affecting diverse brain cell types. Using single-cell transcriptomics, we previously identified selective vulnerability of parvocellular oxytocin (OT) neurons in the paraventricular hypothalamus (PVH) following embryonic exposure to valproic acid (VPA), a teratogen that induces social deficits. Neonatal chemogenetic activation of OT neurons rescued these behavioral abnormalities and partially restored dysregulated gene expression. However, the effects of VPA exposure and OT neuron stimulation on non-neuronal PVH cells remained unclear. Here, we show that VPA induces transcriptional abnormalities in PVH microglia. Spatial transcriptomics revealed altered distributions of PVH microglial subtypes. Notably, neonatal OT neuron stimulation reversed a subset of VPA-induced microglial gene downregulation, while pharmacological manipulation of microglia normalized aberrant OT gene expression in putative parvocellular OT neurons. These findings support bidirectional OT neuron-microglia interactions that may underlie social dysfunction following embryonic VPA exposure. HighlightsO_LIEmbryonic VPA exposure induces potent transcriptional changes in PVH microglia C_LIO_LIPVH microglia comprise two spatially organized subtypes disrupted by VPA C_LIO_LINeonatal OT neuron stimulation restores gene expression in a microglial subtype C_LIO_LIMicroglial manipulation rescues OT ligand in parvocellular PVH neurons C_LI

neuroscience↗

A neuronal population in the bed nucleus of the stria terminalis mediating pup-directed aggression in male mice

The mammalian brain orchestrates a broad range of social behaviors, including interactions with conspecific young. Sexually inexperienced male mice typically exhibit pup-directed aggression, whereas fathers display caregiving behaviors. Although this behavioral transition provides a valuable framework for understanding life stage-dependent modulation of social behavior, the underlying mechanisms remain unclear. The posterior bed nucleus of the stria terminalis (BST), particularly its principal subdivision (BSTpr), is a critical node regulating pup-directed aggression. Within this region, neurons expressing estrogen receptor 1 (Esr1) promote pup-directed aggression in female mice; however, the specific neuronal subtypes mediating this behavior in males remain unknown. Here, reanalysis of single-cell transcriptomic datasets shows that neurons expressing (+) cocaine- and amphetamine-regulated transcript prepropeptide (Cartpt) constitute a subset of Esr1+ neurons within the BST. Exposure to pups selectively increased c-fos expression, a marker of neuronal activation, in BSTpr Cartpt+ neurons in infanticidal virgin males. Chemogenetic activation of these neurons enhanced pup-directed aggression, whereas their ablation suppressed infanticide. Anatomical analyses demonstrated that BSTpr Cartpt+ neurons received direct inhibitory inputs from the anterior commissure nucleus (ACN), a region associated with parental behavior. Additionally, inhibitory transmission from the ACN to BSTpr Cartpt+ neurons was enhanced in fathers. Together, these findings identify BSTpr Cartpt+ neurons as key mediators of pup-directed aggression in male mice, suggesting a neural circuit mechanism underlying the transition from aggression to parental care.

neuroscience↗

Submedius Thalamus Modulates Orbitofrontal Cortex Representations During Maternal Behavior in Mice

The orbitofrontal cortex (OFC) is central to cognitive and social functions, yet its presynaptic partners remain incompletely defined. In female mice, the OFC modulates infant-directed maternal caregiving behaviors essential for offspring survival in an experience-dependent manner. Here, we identify the submedius thalamus (SMT) as a major presynaptic partner of the OFC. Trans-synaptic tracing revealed intensive inputs from both the SMT and mediodorsal thalamus (MD) to OFC layer 5 excitatory neurons. A mouse line Tnnt1-Cre enabled selective targeting of these higher-order thalamic nuclei. Axonal tracing demonstrated complementary projection patterns of SMT and MD across prefrontal regions. Microendoscopic Ca2+ imaging demonstrated pup retrieval encoding in SMT and MD, but only SMT exhibited learning-related plasticity, characterized by enhanced anticipatory responses as acquired maternal behaviors. Projection-specific chemogenetic silencing demonstrated that only SMT modulates OFC activity during pup retrieval. These findings demonstrate SMT as a previously uncharacterized thalamic hub shaping cortical representations of maternal behavior. HighlightsO_LIOFCRbp4 neurons receive strong inputs from higher-order thalamic nuclei (SMT, MD). C_LIO_LISMT and MD show complementary axonal projections across prefrontal cortical cortex. C_LIO_LISMT ensembles encode pup retrieval with experience-dependent plasticity. C_LIO_LISMT inputs selectively modulate pup retrieval representation in OFCRbp4 neurons. C_LI

neuroscience↗

Dissecting Medullary Raphe Neurons Regulating Multiple Thermogenic Pathways

Thermogenesis is critical for survival and health in mammals. Although the thermoregulatory systems in the preoptic area are well documented, the downstream processing of these central signals--particularly by medullary neurons involved in the control of shivering and sympathetic activation of brown adipose tissue (BAT)--remains incompletely understood. Here we show that vesicular glutamate transporter type 3 (vGluT3)-expressing neurons in the medullary raphe pallidus (RPa) become active immediately before a spontaneous increase in body temperature. These neurons remain inactive under experimentally induced hypometabolic conditions and are necessary for rapid recovery from hypothermia. Furthermore, they communicate with multiple brainstem systems involved in the integration of thermal cues. Notably, RPa-vGluT3 neurons can drive shivering via specific brainstem premotor neurons, in addition to regulating sympathetic outflows for BAT thermogenesis and heat-conserving piloerection. These data indicate that RPa-vGluT3 neurons function as medullary hubs, coordinating sympathetic and somatic motor outputs to increase body temperature. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=139 SRC="FIGDIR/small/673572v1_ufig1.gif" ALT="Figure 1"> View larger version (24K): org.highwire.dtl.DTLVardef@12d2e79org.highwire.dtl.DTLVardef@1463498org.highwire.dtl.DTLVardef@27058eorg.highwire.dtl.DTLVardef@1ddee56_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsO_LIRaphe pallidus-vGluT3 neurons are active immediately preceding a spontaneous rise in body temperature. C_LIO_LIThey are suppressed during the state of Q-neuron-induced hypothermia and hypometabolism (QIH). C_LIO_LIThey connect with multiple brainstem pathways involved in thermoregulation. C_LIO_LIThey control shivering via brainstem somatic premotor neurons. C_LI

neuroscience↗

Neural Circuit Remodeling Underlying Enhanced Feeding During Pregnancy in Mice

Pregnancy represents a unique physiological state marked by substantial adaptations influencing both behavior and metabolism1. Alterations have been observed across multiple levels--from changes in cellular morphology, synaptic density, and neuroglial interactions to a brain-wide reduction in gray matter volume2-7. While these adaptations are thought to support offspring survival and promote maternal physiological and psychological well-being8, their functional significance remains largely unresolved. In particular, linking localized synaptic plasticity to a broader brain-wide circuit dynamics has posed a major challenge. Using virus-mediated screening in mice, we investigated the pregnancy-induced remodeling of the presynaptic landscape of paraventricular hypothalamic (PVH) oxytocin neurons, a central hub of maternal physiology9,10. Here we show a selective and reversible elimination of excitatory synaptic inputs from the medial preoptic nucleus to PVH oxytocin neurons, displaying region-, cell-type-, and pathway-specificity. This reduction in excitatory drive attenuated the anorexigenic activity of oxytocin neurons during feeding, thereby promoting the increased food intake characteristic of pregnancy. These data demonstrate that the selective suppression of anorexigenic PVH oxytocin neuron activity plays a critical role in appetite regulation during pregnancy. More broadly, our data identify a pregnancy-associated remodeling of hypothalamic neural circuits with direct physiological relevance.

neuroscience↗

Artificially induced torpor during pregnancy impairs fetal growth in mice

Fetal development in endothermic mammals relies on a tightly regulated maternal body temperature. In animal models, deviations from normothermia during gestation cause fetal developmental abnormalities. However, the direct and physiological manipulation of the maternal core temperature has been technologically challenging, as traditional methods involve the imposition of external thermal stress. Recent advances in the identification of thermoregulatory neurons in the mouse preoptic area have allowed precise control of maternal body temperature without altering environmental conditions. Here we show that the activation of excitatory neurons in the medial preoptic area (MPO) induces a torpor-like hypothermic state in pregnant mice. When induced during early gestation, this state resulted in pregnancy loss, likely due to implantation failure. Hypothermia in mid- and late-gestation reduced fetal liver and kidney size and caused severe growth retardation. Similar outcomes were observed following pyroglutamylated RFamide peptide (Qrfp)-expressing neuron activation in the MPO, whereas inhibitory neuron activation had minimal effect. Furthermore, activating MPO excitatory neurons projecting to the dorsomedial hypothalamic nucleus reproduced both the torpor-like state and fetal growth retardation. These results underscore the importance of a stable maternal body temperature in fetal development and establish a new model for studying the effects of altered maternal temperature on embryogenesis.

neuroscience↗

Expanded gene targeting in RNA hacking with G-tract-supply Staple oligomer

RNA hacking (RNAh) is a gene regulation technology that employs a short oligonucleotide, termed a Staple oligomer, to induce the formation of RNA G-quadruplex structures on target mRNAs. While RNAh has the potential to target approximately 65% of human mRNAs, its applicability to the remaining genes is restricted by the sequence constraints. Herein, we present the G-tract-supply Staple oligomer (Gs-Staple oligomer), designed to expand the range of targetable mRNAs within the RNAh framework. Incorporating G-tracts into Staple oligomers alleviates the sequence constraints, enabling access to a broader range of mRNA targets. Gs-Staple oligomers effectively suppressed the translation of target proteins in mammalian cells and in vivo. Furthermore, the gene suppression could be precisely modulated by adjusting the linker length between the G-tracts. These findings have significantly expanded the versatility of RNAh, suggesting its potential for further development while highlighting its potential to be utilized as a nucleic acid-based tool for research and clinical medicine.

bioengineering↗

Distinct roles of brain network flexibility in motor learning across age

Motor learning is a lifelong process, from infancy through old age. Acquiring new motor actions through repetitive practice requires adjusting motor output in response to sensory input and integrating them to facilitate learning. For this to occur, the central nervous system must flexibly predict and adapt to the dynamic interplay between sensory inputs and motor outputs. Although overall brain function changes with age, it remains unclear how flexible brain networks, reflecting moment-to-moment reconfiguration of large-scale brain networks, influence motor learning ability with aging. To address this, we designed a visuomotor learning task involving both younger and older adults and quantitatively assessed brain network flexibility, leveraging multichannel electroencephalography (EEG) in humans. We found age-group differences in motor learning properties, brain network flexibility, and their neural relationships. In younger adults, the learning aftereffect was associated with brain network flexibility during motor preparation in the learning task. However, this association was not observed in older adults. Together, our findings suggest that brain network flexibility during motor preparation was critical for acquiring and maintaining new motor actions in younger adults, but that this coupling was attenuated with aging.

neuroscience↗

Vasopressin-to-Oxytocin Receptor Crosstalk in the Preoptic Area Underlying Parental Behaviors in Male Mice

The transition to parenthood brings significant changes in behavior toward offspring. For instance, in anticipation of their offspring, male mice shift from infanticidal to caregiving behaviors. While the release of oxytocin from the paraventricular hypothalamus (PVH) plays a critical role in paternal caregiving, it does not fully account for the entire behavioral shift. The specific downstream neurons and signaling mechanisms involved in this process remain obscure. Here, we demonstrate that PVH vasopressin neurons also essentially contribute to a paternal behavioral shift. This vasopressin signal is partially transmitted through oxytocin receptors (OTRs) expressed in the anterior commissure and medial nuclei of the preoptic area. These OTR-expressing neurons receive inputs from both PVH oxytocin and vasopressin neurons and are responsible for expressing paternal caregiving behaviors. Collectively, this non-canonical vasopressin-to-OTR crosstalk within specific limbic circuits acts as a pivotal regulator of paternal behavioral changes in mice. HighlightsO_LIPVH vasopressin neurons are required for and can trigger paternal caregiving behaviors. C_LIO_LIVasopressin-induced paternal behaviors are mediated in part by OTRs in the preoptic area (POA). C_LIO_LIPOA OTR neurons receive inputs from both PVH oxytocin and vasopressin neurons. C_LIO_LIPOA OTR neurons play a critical and facilitative role in promoting paternal caregiving behaviors. C_LI

neuroscience↗

Parallel Labeled-Line Organization of Sympathetic Outflow for Selective Organ Regulation in Mice

The sympathetic nervous system is vital in maintaining homeostasis and responding to environmental changes1-3. This regulation is coordinated by the spinal sympathetic preganglionic neurons (SPNs), which influence various organs both through neuronal pathways via postganglionic neurons and through endocrine processes by innervating the adrenal gland. Despite decades of research supporting the concept of selective control within this system1,4-9, the neural circuit organization responsible for the specificity of sympathetic outflow remains poorly understood. Notably, classical anatomical studies in rats have not revealed a definitive molecular code governing SPNs, nor have they confirmed the existence of SPNs strictly corresponding to specific output targets1,6,10,11. To reconcile this discrepancy, we aim to integrate recent transcriptome data of SPNs12,13 in mice with viral-genetic toolkits14 to map axonal projections and manipulate the functions of SPNs governing the gastrointestinal tract and adrenal gland. Here, we have identified two subtypes of SPNs in the lower thoracic spinal cord, defined at the molecular level, exhibiting non-overlapping patterns of innervation. Chemogenetic manipulations on these distinct SPN subtypes revealed selective impacts on the digestive functions in the gastrointestinal tracts or glucose metabolism mediated by the adrenal gland, respectively. This molecularly delineated parallel labeled-line organization in sympathetic outflows presents a potential avenue for selectively manipulating organ functions.

neuroscience↗

Selective Vulnerability of Parvocellular Oxytocin Neurons in Social Dysfunction

Selective vulnerability offers a conceptual framework for understanding neurodegenerative disorders, such as Parkinsons disease, where specific neuronal types are selectively affected while adjacent ones are spared. The applicability of this framework to neurodevelopmental disorders remains uncertain, particularly those characterized by atypical social behaviors such as autism spectrum disorder. Here, employing a single-cell transcriptome analysis in mice, we show that an embryonic disturbance known to induce social dysfunction preferentially impairs gene expressions crucial for neural functions in parvocellular oxytocin (OT) neurons--a subtype linked to social rewards--while neighboring cell types experience a lesser impact. Chemogenetic stimulation of OT neurons at the neonatal stage ameliorated social deficits in early adulthood, concurrent with a cell-type-specific sustained recovery of the pivotal gene expressions within parvocellular OT neurons. Collectively, our data shed light on the transcriptomic selective vulnerability within the hypothalamic social behavioral center and provide a potential therapeutic target through specific neonatal neurostimulation.

neuroscience↗

Dietary Availability Acutely Governs Puberty Onset via Hypothalamic Neural Circuit

Reproduction poses a substantial burden, especially for mammalian females. Puberty onset serves as a vital checkpoint, regulated based on the bodys energy state, to prevent inappropriate reproductive activity under malnutrition. However, the neural basis of this puberty checkpoint remains poorly understood. Here, we demonstrate that peripubertal malnutrition in female mice reduces the synchronous activity episodes of arcuate kisspeptin neurons (SEskiss), which are critical regulators of the gonadotropin axis. Improved dietary availability boosts SEskiss frequency, facilitating puberty onset. Using a viral-genetic approach, we show that the activating agouti-related protein neurons in the arcuate nucleus (ARCAgrp neurons), a hunger center, suppresses SEskiss, even with enough food. Conversely, loss-of-function of ARCAgrp neurons enhances SEskiss during malnutrition, partly promoting irregular sexual maturation. Collectively, a neural circuit connecting feeding to reproductive centers is responsible for disinhibiting SEskiss frequency based on dietary availability, which sheds light on the neural basis of puberty checkpoint. HighlightsO_LIThe pulsatile activity of arcuate kisspeptin neurons emerges and grows before vaginal opening. C_LIO_LIPubertal impairment resulting from malnutrition is associated with a reduction in the pulsatile activity of kisspeptin neurons. C_LIO_LIPubertal recovery by food availability follows the elevated pulsatile activity of kisspeptin neurons during catch-up growth. C_LIO_LIThe arcuate Agrp neurons suppress the frequency of pulsatile activity of kisspeptin neurons under negative energy balance. C_LI

neuroscience↗

In Vivo mRNA Hacking with Staple Oligomers Prevents Myocardial Hypertrophy

Summary paragraphThe elucidation of gene-silencing mechanisms by RNA interference (RNAi) and antisense oligomers has drawn increasing attention to nucleic acid medicine. However, several challenges remain to be overcome, such as in vivo stability1, target selectivity 2,3, drug delivery4,5, and induced innate immunity6. Here, we report a new, versatile, and highly-selective method to hack RNA by controlling RNA structure using short oligonucleotides (RNA hacking: RNAh) in living cells. The oligonucleotide, named Staple oligomer, hybridizes specifically to a target mRNA and artificially induces an RNA higher-order structure, RNA G-quadruplex (RGq)7, on the mRNA. As a result, the RGq allows effective suppression of the target protein translation. This technology does not require cooperation with bioprocesses including enzymatic reactions as in RNAi or antisense technologies, permitting the introduction of artificial nucleic acids into Staple oligomers to increase their in vivo stability without compromising their effectiveness. The method was validated by translational regulation of the mRNAs of TPM3, MYD88, and TRPC6, in a cell-free system and in living mammalian cells. In vivo application of the technology to TRPC6 mRNA allowed us to prevent cardiac hypertrophy in transverse aortic constriction (TAC)-treated mice with no detectable off-target effects. This technology provides new insights into gene therapy after RNAi and antisense technologies.

molecular biology↗

A Prefrontal Neural Circuit for Maternal Behavioural Leaning in Mice

Maternal behaviors, which are crucial for the survival of mammalian infants, require the coordinated operation of multiple brain regions to process infant cues, make decisions, and execute motor plans. Although these processes likely demand higher cognitive functions, the prefrontal areas that regulate limbic parental programs remains poorly understood. Here, we show that the orbitofrontal cortex (OFC) excitatory projection neurons promote alloparental caregiving behaviors in female mice. By chronic microendoscopy, we observed robust yet adaptable representations of pup-directed anticipatory and motor-related activities within the OFC. Some of these plastic responses were significantly overlapped with those related to nonsocial reward signals. The inactivation of OFC output reduced the phasic activities of midbrain dopamine (DA) neurons specifically tied to pup retrieval and impaired the modulation of DA release to the ventral striatum during the acquisition of alloparental behaviors. These findings suggest that the OFC transiently boosts DA activity during the acquisition phase, thereby facilitating the manifestation of alloparental behaviors.

neuroscience↗

Dynamic Modulation of Pulsatile Activities of Oxytocin Neurons in Lactating Wild-type Mice

Breastfeeding, which is essential for the survival of mammalian infants, is critically mediated by pulsatile secretion of the pituitary hormone oxytocin from the central oxytocin neurons located in the paraventricular and supraoptic hypothalamic nuclei of mothers. Despite its importance, the molecular and neural circuit mechanisms of the milk ejection reflex remain poorly understood, in part because a mouse model to study lactation was only recently established. In our previous study, we successfully introduced fiber photometry-based chronic imaging of the pulsatile activities of oxytocin neurons during lactation. However, the necessity of Cre recombinase-based double knock-in mice substantially compromised the use of various Cre-dependent neuroscience toolkits. To overcome this obstacle, we developed a simple Cre-free method for monitoring oxytocin neurons by an adeno-associated virus vector driving GCaMP6s under a 2.6 kb mouse oxytocin mini-promoter. Using this method, we monitored calcium ion transients of oxytocin neurons in the paraventricular nucleus in wild-type C57BL/6N and ICR mothers without genetic crossing. By combining this method with video recordings of mothers and pups, we found that the pulsatile activities of oxytocin neurons require physical mother-pup contact for the milk ejection reflex. Notably, the frequencies of photometric signals were dynamically modulated by mother-pup reunions after isolation and during natural weaning stages. Collectively, the present study illuminates the temporal dynamics of pulsatile activities of oxytocin neurons in wild-type mice and provides a tool to characterize maternal oxytocin functions.

neuroscience↗