Biology subjects

Emoto, K.

Publications and source records attributed to Emoto, K..

10 recordsLinked to original sources

bioRxiv2026

A post-inflammatory C3-high astrocyte state persists after inflammatory stimulus withdrawal and is attenuated by JAK inhibition

Reactive astrocytes contribute to neuroinflammation and synaptic dysfunction, but it remains unclear whether transient inflammatory stimulation causes a persistent reactive state after the initial inflammatory stimulus is removed. Here, we investigated whether transient exposure to a defined inflammatory cytokine/complement cocktail induces a persistent reactive astrocyte state and examined the signaling mechanism underlying its maintenance. Human astrocytes were exposed to the inflammatory stimulus and subsequently subjected to stimulus washout, followed by time-course analyses to compare the reversibility of inflammatory gene expression after stimulus removal. Following washout, the expression of several inflammatory response genes, including CXCL10 and NF-{kappa}B-associated genes such as NFKBIA, TNFAIP3, and RELB, returned toward baseline levels. In contrast, C3 expression remained elevated, indicating persistence of a post-inflammatory C3-high astrocyte state after withdrawal of the inflammatory stimulus. Pharmacological inhibition of JAK signaling reduced persistent C3 expression to near-baseline levels, supporting the involvement of JAK-dependent signaling in maintenance of this persistent state. Together, these findings suggest that transient inflammatory stimulation induces a post-inflammatory persistent C3-high astrocyte state that is maintained even after broader inflammatory gene responses have subsided. This persistent C3-high component is pharmacologically attenuated by JAK inhibition, identifying JAK-dependent pathways as modulators of persistent astrocyte inflammatory reactivity.

neuroscience↗

bioRxiv2026

A neural substrate for resistance to change in the ventral hippocampus

Strong prior beliefs can render individuals resistant to change, even when outcomes contradict expectations, yet the neural mechanisms supporting such stability remain poorly understood. Here we show that the ventral hippocampus (vCA1) actively stabilizes inferred contextual state (belief) during aversive memory extinction in a behavior-dependent manner. Using in vivo calcium imaging, we identify a subset of vCA1 neurons that exhibit selective reductions in activity when expected aversive outcomes do not occur during extinction. Axonal calcium imaging further reveals that reduced signals are broadcast to basal amygdala, nucleus accumbens, and medial prefrontal cortex. Optogenetic manipulations demonstrate that these signals actively suppress extinction learning and promote persistence of defensive response. Computational modeling indicates that vCA1 omission-related signals reflect discrepancies between beliefs and observed omission of the expected outcome, thereby maintaining the aversive belief. Crucially, convergent evidence from calcium imaging, modelling, and closed-loop optogenetic manipulations reveals that vCA1 omission-related signals are specific to the period during which animals execute defensive behavior driven by their inferred aversive state. These findings identify a novel mechanism in vCA1 that stabilizes inferred aversive state despite changes in stimulus contingencies and suggest a key role of vCA1 in belief-based control of learning.

neuroscience↗

bioRxiv2025

Dopaminergic Neurons in the Brain Orchestrates Cardiac and Behavioral Threat Responses

Heartbeat and behavior are tightly coordinated during defensive states, yet the neuronal mechanisms linking threat processing to cardiac modulation--and the potential contribution of cardiac dynamics to behavioral output--remain poorly understood. Here we show in Drosophila that mechanical threat triggers locomotion together with cardiac deceleration. We identify two pairs of dopaminergic neurons, termed DA-WED neurons, that mediate this cardiac response: silencing these neurons markedly attenuates threat-induced cardiac deceleration, whereas optogenetic activation induces cardiac deceleration in the absence of threat. Calcium imaging further shows that DA-WED neurons are activated by mechanical threat. Linking cardiac dynamics to behavior, direct optogenetic manipulation of cardiomyocytes that quantitatively reproduces threat-evoked cardiac deceleration is accompanied by increased locomotion. Together, these results identify a dopaminergic descending pathway that links threat processing to cardiac modulation and suggest that cardiac dynamics may contribute to shaping defensive behavior.

neuroscience↗

bioRxiv2025

Human-specific NOTCH2NL promotes astrogenesis by expanding proliferative glial progenitor states

The human cerebral cortex contains an unusually large number of glial cells, particularly astrocytes, yet the developmental and genetic mechanisms underlying their expansion remain poorly understood. While human-specific genes have been shown to promote neuronal production during cortical development, whether such genes also regulate gliogenesis has remained unclear. Here, we identify a previously unrecognized role for the human-specific gene family NOTCH2NL in promoting astrocyte-lineage expansion. Reanalysis of human fetal single-cell transcriptomic datasets revealed that NOTCH2NL is robustly expressed along the gliogenic trajectory, from glial intermediate progenitor cells to astrocytes. Functional perturbations in a human astrocyte culture system demonstrated that NOTCH2NL is both required and sufficient for astrocyte proliferation. In vivo overexpression of NOTCH2NLB in the developing mouse cortex shifted progenitor output toward the astrocyte lineage, increasing the astrocyte-to-neuron ratio from the early postnatal period through adulthood. This phenotype was associated with an expansion of proliferative glial progenitors around birth. Single-nucleus transcriptomic profiling further showed that NOTCH2NLB suppresses neuronal gene programs while activating transcriptional modules related to cell proliferation and cellular homeostasis during gliogenesis. Together, these findings indicate that human-specific NOTCH2NL acts at a conserved developmental decision point to amplify astrocyte production. Our study extends the function of NOTCH2NL beyond neurogenesis and suggests that human lineage-specific gene duplications can modulate gliogenesis, providing a developmental mechanism that may have contributed to the coordinated expansion of neuronal and glial populations in the human cortex.

developmental biology↗

bioRxiv2025

Repeated stress persistently suppressesthe central node in the courtship circuitry in Drosophila

Stress caused by external stressors, such as painful stimulation, can elicit a drastic set of behavioral responses. Such stress responses normally decay soon after the stressor disappears, but can become persistent when the stressor becomes longer and/or repeated. The neuronal mechanism underlying the persistence of stress responses, however, remains elusive. Here, we discovered that repeated electric shocks persistently suppress male Drosophilas courtship behavior. We comprehensively evaluated the physiological changes in the genetically defined courtship circuitry, and found that a courtship-triggering node of the circuitry, called P1 neurons, is preferentially and persistently suppressed following electric shocks. Our data uncovers in a comprehensively defined courtship circuitry that repeated stress persistently suppresses a critical node of the circuitry in a targeted fashion to alter behavior.

neuroscience↗

bioRxiv2025

Heat-off responses of epidermal cells sensitize Drosophila larvae to noxious inputs

Perception of external thermal stimuli is critical to animal survival, and although an animals skin is the largest contact surface for thermal inputs, contributions of skin cells to noxious temperature sensing have not been extensively explored. Here, we show that exposure to heat transiently sensitizes Drosophila larvae to subsequent noxious stimuli. This sensitization is induced by prior stimulation of epidermal cells but not nociceptors, suggesting that epidermal cells modulate nociceptor function in response to heat exposure. Indeed, we found that Drosophila epidermal cells are intrinsically thermosensitive, exhibiting robust heat-off responses following warming to noxious temperatures as well as responses to cooling below comfortable temperatures. Further, we found that epidermal heat-off calcium responses involve influx of extracellular calcium and require the store-operated calcium channel Orai and its activator Stim. Finally, epidermal heat-off responses and heat-evoked nociceptive sensitization exhibit similar temperature dependencies, and we found that Stim and Orai are required in epidermal cells for heat-evoked nociceptive sensitization. Hence, epidermal thermosensory responses provide a form of adaptive sensitization to facilitate noxious heat avoidance.

neuroscience↗

bioRxiv2025

Non-uniform temporal scaling of neurogenesis for species-specific dosing of cortical excitatory subtypes

Mammals share a laminar cerebral cortex, with excitatory neuron subtypes organized in distinct layers. Although this framework is conserved, subtype balance varies markedly between species due to unknown mechanisms. This study shows that species-specific neuronal composition arises from non-uniform scaling of the temporal dynamics of neurogenesis. Comparative histology of eight mammalian species revealed a significant, rat-specific expansion of the cortical deeper layer (DL). This species difference results from a specific extension of the early neurogenetic phase for DL neuron production before transitioning to the upper layer (UL) in rats, as confirmed by birthdating and single-cell transcriptomics. The duration of DL neuron production is regulated by a genetic program controlling progenitor aging, including canonical Wnt signaling. Comparative single-cell transcriptomics revealed that cortical progenitors in rats exhibit significantly elevated Wnt ligand expression. Thus, while sequential cortical neurogenesis is conserved, its progression is non-uniformly scaled in each species. Such precise heterochronic fine-tuning allows evolutionary refinement of cellular configuration without drastic remodeling of the conserved corticogenesis program. TeaserDifferential temporal progression of neural progenitor program contributes to species-specific cellular composition of mammalian cerebral cortex

developmental biology↗

bioRxiv2025

Neuropeptidergic circuit modulation of developmental sleep in Drosophila

Sleep-wakefulness regulation dynamically evolves along development in a wide range of organisms. While the mechanism regulating sleep in adults are relatively well understood, little is known about its counterpart in early developmental stages. Here we report a neuropeptidergic circuitry that modulates sleep in developing Drosophila larvae. Through an unbiased screen, we identified the neuropeptide Hugin and its receptor PK2-R1 as critical regulators of larval sleep. Our genetic and behavioral data suggest that HugPC neurons secrete Hugin peptides to activate Insulin-producing cells (IPCs), which expresses a Hugin receptor PK2-R1. IPCs, in turn, release insulin-like peptides (Dilps) to regulate sleep. We further show that the Hugin/PK2-R1 axis is dispensable for adult sleep. Our findings thus reveal the neuromodulatry circuit that regulates developmental sleep in larvae, and highlight differential impacts of the same modulatory axis on early-life sleep and adult sleep.

neuroscience↗

bioRxiv2024

Flow zoometry of Drosophila

Drosophila serves as a highly valuable model organism across numerous fields including genetics, immunology, neuroscience, cancer biology, and developmental biology. Central to Drosophila-based biological research is the ability to perform comprehensive genetic or chemical screens. However, this research is often limited by its dependence on laborious manual handling and analysis, making it prone to human error and difficult to discern statistically significant or rare events amid the noise of individual variations resulting from genetic and environmental factors. In this article we present flow zoometry, a whole-animal equivalent of flow cytometry for large-scale, individual-level, high-content screening of Drosophila. Our flow zoometer automatically clears the tissues of Drosophila melanogaster, captures three-dimensional (3D) multi-color fluorescence tomograms of single flies with single-cell volumetric resolution at an unprecedented throughput of over 1,000 animals within 48 hours (24 hr for clearing; 24 hr for imaging), and performs AI-enhanced data-driven analysis - a task that would traditionally take months or years with manual techniques. To demonstrate its broad applications, we employed the flow zoometer in various laborious screening assays, including those in toxicology, genotyping, and tumor screening. Flow zoometry represents a pivotal evolution in high-throughput screening technology: previously from molecules to cells, now from cells to whole animals. This advancement serves as a foundational platform for "statistical spatial biology", to improve empirical precision and enable serendipitous discoveries across various fields of biology.

bioengineering↗

bioRxiv2022

Drosophila epidermal cells are intrinsically mechanosensitive and drive nociceptive behavioral outputs

Somatosensory neurons (SSNs) that detect and transduce mechanical, thermal, and chemical stimuli densely innervate an animals skin. However, although epidermal cells provide the first point of contact for sensory stimuli. our understanding of roles that epidermal cells play in SSN function, particularly nociception, remains limited. Here, we show that stimulating Drosophila epidermal cells elicits activation of SSNs including nociceptors and triggers a variety of behavior outputs, including avoidance and escape. Further, we find that epidermal cells are intrinsically mechanosensitive and that epidermal mechanically evoked calcium responses require the store-operated calcium channel Orai. Epidermal cell stimulation augments larval responses to acute nociceptive stimuli and promotes prolonged hypersensitivity to subsequent mechanical stimuli. Hence, epidermal cells are key determinants of nociceptive sensitivity and sensitization, acting as primary sensors of noxious stimuli that tune nociceptor output and drive protective behaviors.

neuroscience↗