Biology subjects

Dulac, C.

Publications and source records attributed to Dulac, C..

16 recordsLinked to original sources

bioRxiv2025

Cell Type-Specific Hormonal Signaling Configures Hypothalamic Circuits for Parenting

Parenting behavior emerges from hormonally sensitive circuits, but how distinct circuit components are affected by, and contribute to, sex and state dependent changes in infant caregiving remains unclear. Using cell type-specific approaches, we characterized two circuit nodes that are differentially configured by hormones to modulate infant-evoked behavior. An excitatory neuronal population in the anteroventral periventricular nucleus is only active in lactating mothers, increases virgin female caregiving when artificially stimulated and confers oxytocin sensitivity in mothers through a prolactin-STAT5b pathway. These neurons function upstream of another preoptic area population involved in male and female parenting, thus boosting caregiving by mothers. By contrast, androgen signaling in the latter preoptic population reshapes their intrinsic properties to promote pup-directed aggression, revealing cell type-specific tuning of social behavior circuits.

neuroscience↗

bioRxiv2025

Brain-immune interactions generate pathogen-specific sickness states

In nature, animals encounter diverse pathogens that trigger specific peripheral defense programs and elicit sickness behavior, a set of stereotyped physiological and behavioral changes thought to promote host fitness. Most studies to date have relied on one or a few mouse models of infection, limiting insights into pathogen-specific neuroimmune interactions that generate sickness. We hypothesized that different pathogens might elicit distinct sickness states by engaging different cell types and brain circuits. Using inflammatory models representing bacterial, viral, allergic, parasitic or colitis conditions, we assessed sickness across scales: organismal - behavior and physiology; cellular - brain-wide neural activity; and molecular - single-cell in situ transcriptomics in hypothalamus areas associated with social and homeostatic functions affected during sickness. Remarkably, immune challenges elicited unique repertoires of changes across all scales. Our findings reveal pathogen-specific sickness states encoded by the brain across scales, thereby broadening our understanding of how infections make us sick.

neuroscience↗

bioRxiv2025

A genetically-defined population of amygdalofugal neurons promotes suckling and early postnatal growth

Suckling by newborns is an instinctive behavior defining the mammalian class. Yet, due to experimental difficulty in assessing neural function in the very young, little is known about the neural control of this fundamental behavior. Here we develop molecular-genetic approaches to interrogate neuronal connectivity and function in newborn mice and used these tools to identify a population of pro-dynorphin (PDYN) and somatostatin (SST) expressing neurons in the central amygdala that are activated during suckling. CeAPDYN+SST+ neurons connect with brainstem areas mediating oral sensorimotor and reward function in adults, and their ablation in newborns decreases suckling vigor and impairs growth. These results uncover the crucial role of a specific neuronal population of the central amygdala in maintaining the infants propensity to suckle and thrive throughout infancy.

neuroscience↗

bioRxiv2025

Concerted actions of distinct serotonin neurons orchestrate female pup care behavior

In many mammalian species, female behavior towards infant conspecifics changes across reproductive stages. Sexually naive females interact minimally or aggressively with infants, whereas the same animals exhibit extensive care behavior, even towards unrelated infants, after parturition1-6. Here, we discovered that two distinct sets of serotonin neurons collectively mediate this dramatic transition in maternal behavior--serotonin neurons projecting to the medial preoptic area (mPOA) promote pup care in mothers, whereas those projecting to the bed nucleus of the stria terminalis (BNST) suppress pup interaction in virgin female mice. Disrupting serotonin synthesis in either of these subpopulations or stimulating either subpopulation is sufficient to toggle pup-directed behavior between that displayed by virgin females and that of lactating mothers. In virgin female mice, the first pup interaction triggers an increase in serotonin release in BNST but a decrease in mPOA. In mothers, serotonin activity becomes greatly elevated in mPOA during pup interactions. Acute interruption of serotonin signaling locally in either mPOA or BNST disrupts the stage-dependent switch in pup care. Together, these results highlight how functionally distinct serotonin subpopulations orchestrate social behaviors appropriate for a given reproductive state, and suggest a circuit logic for how a neuromodulator coordinates adaptive behavioral changes across life stages.

neuroscience↗

bioRxiv2025

Molecular and Spatial Organization of the Primary Olfactory System and its Responses to Social Odors

The detection of olfactory cues is essential to signal food, predators, and social encounters. To determine how the sensory detection of physiologically relevant odors is systematically mapped into the mouse primary olfactory system, we used Multiplexed Error Robust Fluorescent In Situ Hybridization (MERFISH) to construct a molecular atlas of odorant receptor (OR) expression in the main olfactory epithelium (MOE) and olfactory bulb (OB). We comprehensively quantified the expression of the mouse OR repertoire and uncovered stereotypical gradients of sensory neuron distribution in the MOE along two, central-to-peripheral and basal-to-apical, axes. Projections of sensory neurons mirror MOE gradients along the dorsal-ventral and anterior-posterior axes of the OB, respectively. Integration with sequencing data revealed candidate signaling molecules underlying this spatial organization. Co-imaging OR and activity marker expression identified distinct spatial domains of sensory responses in the MOE and OB, providing a topographical basis for olfactory responses to ethologically relevant odors.

neuroscience↗

bioRxiv2024

A platform for multimodal in vivo pooled genetic screens reveals regulators of liver function

Organ function requires coordinated activities of thousands of genes in distinct, spatially organized cell types. Understanding the basis of emergent tissue function requires approaches to dissect the genetic control of diverse cellular and tissue phenotypes in vivo. Here, we develop paired imaging and sequencing methods to construct large-scale, multi-modal genotype-phenotypes maps in tissue with pooled genetic perturbations. Using imaging, we identify genetic perturbations in individual cells while simultaneously measuring their gene expression and subcellular morphology. Using single-cell sequencing, we measure transcriptomic responses to the same genetic perturbations. We apply this approach to study hundreds of genetic perturbations in the mouse liver. Our study reveals regulators of hepatocyte zonation and liver unfolded protein response, as well as distinct pathways that cause hepatocyte steatosis. Our approach enables new ways of interrogating the genetic basis of complex cellular and organismal physiology and provides crucial training data for emerging machine-learning models of cellular function.

genomics↗

bioRxiv2024

Sensory Input, Sex, and Function Shape Hypothalamic Cell Type Development

Mammalian behavior and physiology undergo dramatic changes in early life. Young animals rely on conspecifics to meet their homeostatic needs, until weaning and puberty initiate nutritional independence and sex-specific social interactions, respectively. How neuronal populations regulating homeostatic functions and social behaviors develop and mature during these transitions remains unclear. We used paired transcriptomic and chromatin accessibility profiling to examine the developmental trajectories of neuronal populations in the hypothalamic preoptic region, where cell types with key roles in physiological and behavioral control have been identified1-6. These data reveal a remarkable diversity of developmental trajectories shaped by the sex of the animal, and the location and behavioral or physiological function of the corresponding cell types. We identify key stages of preoptic development, including the perinatal emergence of sex differences, postnatal maturation and subsequent refinement of signaling networks, and nonlinear transcriptional changes accelerating at the time of weaning and puberty. We assessed preoptic development in various sensory mutants and find a major role for vomeronasal sensing in the timing of preoptic cell type maturation. These results provide novel insights into the development of neurons controlling homeostatic functions and social behaviors and lay ground for examining the dynamics of these functions in early life.

neuroscience↗

bioRxiv2023

Three-dimensional single-cell transcriptome imaging of thick tissues

Multiplexed error-robust fluorescence in-situ hybridization (MERFISH) allows genome-scale imaging of RNAs in individual cells in intact tissues. To date, MERFISH has been applied to image thin tissue samples of [~]10-{micro}m thickness. Here, we present a thick-tissue three-dimensional (3D) MERFISH imaging method, which uses confocal microscopy for optical sectioning, deep learning for increasing imaging speed and quality, as well as sample preparation and imaging protocol optimized for image registration of thick samples. We demonstrated 3D MERFISH on mouse brain tissue sections of up to 200 {micro}m thickness with high detection efficiency and accuracy. We anticipate that 3D thick-tissue MERFISH imaging will broaden the scope of questions that can be addressed by spatial genomics.

neuroscience↗

bioRxiv2023

A Hypothalamic Circuit Underlying the Dynamic Control of Social Homeostasis

Social grouping increases survival in many species, including humans1,2. By contrast, social isolation generates an aversive state (loneliness) that motivates social seeking and heightens social interaction upon reunion3-5. The observed rebound in social interaction triggered by isolation suggests a homeostatic process underlying the control of social drive, similar to that observed for physiological needs such as hunger, thirst or sleep3,6. In this study, we assessed social responses in multiple mouse strains and identified the FVB/NJ line as exquisitely sensitive to social isolation. Using FVB/NJ mice, we uncovered two previously uncharacterized neuronal populations in the hypothalamic preoptic nucleus that are activated during social isolation and social rebound and that orchestrate the behavior display of social need and social satiety, respectively. We identified direct connectivity between these two populations of opposite function and with brain areas associated with social behavior, emotional state, reward, and physiological needs, and showed that animals require touch to assess the presence of others and fulfill their social need, thus revealing a brain-wide neural system underlying social homeostasis. These findings offer mechanistic insight into the nature and function of circuits controlling instinctive social need and for the understanding of healthy and diseased brain states associated with social context.

neuroscience↗

bioRxiv2022

Mapping the cellular and molecular organization of mouse cerebral aging by single-cell transcriptome imaging

The cellular diversity and complex organization of the brain have hindered systematic characterization of age-related changes in its cellular and molecular architecture, limiting our ability to understand the mechanisms underlying its functional decline during aging. Here we generated a high-resolution cell atlas of brain aging within the frontal cortex and striatum using spatially resolved single-cell transcriptomics and quantified the changes in gene expression and spatial organization of major cell types in these brain regions over the lifespan of mice. We observed substantially more pronounced changes in the composition, gene expression and spatial organization of non-neuronal cells over neurons. Our data revealed molecular and spatial signatures of glial and immune cell activation during aging, particularly enriched in subcortical white matter, and identified both similarities and notable differences in cell activation patterns induced by aging and systemic inflammatory challenge. These results provide critical insights into age-related decline and inflammation in the brain.

neuroscience↗

bioRxiv2022

Three-dimensional Interrogation of Cell Types and Instinctive Behavior in the Periaqueductal Gray

The periaqueductal gray (PAG) is a critical midbrain hub that relays information from the forebrain to motor and autonomic brainstem centers to orchestrate instinctive behaviors. The current organization of the PAG into four main radial columns lacks the resolution needed to account for the vast range of PAG functions. Using spatially resolved single-cell transcriptomic measurements, we uncovered widespread transcriptional heterogeneity in the PAG with >100 excitatory and inhibitory neuronal populations, which further assemble into 19 spatial metaclusters. We explored the transcriptional and spatial logic of PAG function during instinctive behaviors and demonstrated the regional recruitment of cell types for distinct behaviors. Unexpectedly, certain behaviors trigger differential spatial activation patterns within given cell types, illustrating the complexity of PAG molecular and functional 3D organization. The newly uncovered spatial motifs and high precision cellular map of instinctive behavior in the PAG open new avenues for a mechanistic understanding of PAG function.

neuroscience↗

bioRxiv2021

Multi-animal pose estimation and tracking with DeepLabCut

Estimating the pose of multiple animals is a challenging computer vision problem: frequent interactions cause occlusions and complicate the association of detected keypoints to the correct individuals, as well as having extremely similar looking animals that interact more closely than in typical multi-human scenarios. To take up this challenge, we build on DeepLabCut, a popular open source pose estimation toolbox, and provide high-performance animal assembly and tracking--features required for robust multi-animal scenarios. Furthermore, we integrate the ability to predict an animals identity directly to assist tracking (in case of occlusions). We illustrate the power of this framework with four datasets varying in complexity, which we release to serve as a benchmark for future algorithm development.

animal behavior and cognition↗

bioRxiv2020

Evaluating single-cell cluster stability using the Jaccard similarity index

MotivationOne major goal of single-cell RNA sequencing (scRNAseq) experiments is to identify novel cell types. With increasingly large scRNAseq datasets, unsupervised clustering methods can now produce detailed catalogues of transcriptionally distinct groups of cells in a sample. However, the interpretation of these clusters is challenging for both technical and biological reasons. Popular clustering algorithms are sensitive to parameter choices, and can produce different clustering solutions with even small changes in the number of principal components used, the k nearest neighbor, and the resolution parameters, among others. ResultsHere, we present a set of tools to evaluate cluster stability by subsampling, which can guide parameter choice and aid in biological interpretation. The R package scclusteval and the accompanying Snakemake workflow implement all steps of the pipeline: subsampling the cells, repeating the clustering with Seurat, and estimation of cluster stability using the Jaccard similarity index. The Snakemake workflow takes advantage of high-performance computing clusters and dispatches jobs in parallel to available CPUs to speed up the analysis. The scclusteval package provides functions to facilitate the analysis of the output, including a series of rich visualizations. AvailabilityR package scclusteval: https://github.com/crazyhottommy/scclusteval Snakemake workflow: https://github.com/crazyhottommy/pyflow_seuratv3_parameter Contacttsackton@g.harvard.edu, tangming2005@gmail.com Supplementary informationSupplementary data are available at Bioinformatics online.

bioinformatics↗

bioRxiv2019

Molecular and Circuit Architecture of Social Hierarchy

Social hierarchy is a common organizational structure of animal groups, in which an individuals social status generates an adaptive behavioral state that facilitates interactions with other group members. Although generally stable, the social status of an animal can change, underscoring the plasticity of the underlying neural circuits. Here, we uncover the molecular and biophysical properties of a cortico-thalamic circuit that supports the emergence of hierarchy in mice. We established a robust behavioral paradigm to explore the establishment of hierarchy among groups of unfamiliar males, and identified the mediodorsal thalamus (MDT) and the caudal part of anterior cingulate area (cACC) as brain areas that are differentially activated between dominants and subordinates. Glutamatergic MDT neurons project to inhibitory parvalbumin interneurons of the cACC, and activity levels of both cell types control competitive performance. Synaptic inputs and excitability of MDT neurons undergo dramatic changes according to the animal social status, and single nucleus sequencing identified increased transcription of the voltage gated ion channel Trpm3 in dominant mice, leading to enhanced excitatory transmission in the MDT-cACC circuit. Our data suggest a model in which cellular, molecular and biophysical plasticity in a thalamocortical circuit controls the expression of social status.

neuroscience↗

bioRxiv2019

Perifornical Area Urocortin-3 Neurons Promote Infant-directed Neglect and Aggression

While recent studies have uncovered dedicated neural pathways mediating the positive control of parenting, the regulation of infant-directed aggression and how it relates to adult-adult aggression is poorly understood. Here we show that urocortin-3 (Ucn3)-expressing neurons in the hypothalamic perifornical area (PeFAUcn3) are activated during infant-directed attacks in males and females, but not other behaviors. Functional manipulations of PeFAUcn3 neurons demonstrate the role of this population in the negative control of parenting in both sexes. PeFAUcn3 neurons receive input from areas associated with vomeronasal sensing, stress, and parenting, and send projections to hypothalamic and limbic areas. Optogenetic activation of PeFAUcn3 axon terminals in these regions triggers various aspects of infant-directed agonistic responses, such as neglect, repulsion and aggression. Thus, PeFAUcn3 neurons emerge as a dedicated circuit component controlling infant-directed neglect and aggression, providing a new framework to understand the positive and negative regulation of parenting in health and disease.

neuroscience↗

bioRxiv2017

Oxytocin Signaling in the Medial Amygdala is required for Sex Discrimination of Social Cues

The neural control of social behaviors in rodents requires the encoding of pheromonal cues by the vomeronasal system. Here we show that the typical preference of male mice for females is eliminated in mutants lacking oxytocin, a neuropeptide modulating social behaviors in many species. Ablation of the oxytocin receptor in aromatase expressing neurons of the medial amygdala (MeA) fully recapitulates the elimination of female preference in males. Further, single unit recording in the MeA uncovered significant changes in the sensory representation of conspecific cues in the absence of oxytocin signaling. Finally, acute manipulation of oxytocin signaling in adults is sufficient to alter social interaction preferences in males as well as responses of MeA neurons to chemosensory cues. These results uncover the critical role of oxytocin signaling in a molecularly defined neuronal population in order to modulate the behavioral and physiological responses of male mice to females on a moment-to-moment basis.

neuroscience↗