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Nestler, E. J.

Publications and source records attributed to Nestler, E. J..

At least 19 recordsLinked to original sources

Protracted abstinence from heroin, but not cocaine, is associated with profound medial prefrontal cortex synaptic bioenergetic remodeling and lasting neural hypofunction

Relapse following prolonged abstinence is a primary challenge in the treatment of opioid and cocaine use disorders, driven in part by enduring dysfunction of medial prefrontal cortex (mPFC) circuits that impair inhibitory control over drug-seeking. The molecular substrates underlying this dysfunction, and whether they differ across drug classes, remain unknown. Here, we performed label-free quantitative proteomics of mPFC synaptosomes isolated from rats after 30-day abstinence following intravenous heroin or cocaine self-administration to profile synaptic adaptations that may contribute to relapse vulnerability. Heroin abstinence induced extensive synaptic proteomic remodeling characterized by coordinated downregulation of mitochondrial proteins involved in oxidative phosphorylation, including pyruvate dehydrogenase complex subunits that regulate carbon entry into mitochondrial metabolism. Targeted metabolomic profiling of whole mPFC revealed accumulation of upstream glycolytic and pentose phosphate pathway intermediates, consistent with altered pyruvate utilization and mitochondrial oxidation. Several bioenergetic metabolites also correlated positively with the severity of escalation of heroin intake. Consistent with the bioenergetic remodeling observed during protracted heroin abstinence, whole-cell patch-clamp recordings from layer V mPFC pyramidal neurons revealed lasting suppression of intrinsic excitability and a decreased spontaneous excitatory synaptic activity. Cocaine abstinence, by contrast, produced limited changes in synaptic bioenergetics while inducing a distinct cytoskeletal remodeling signature. Overall, these findings identify synaptic bioenergetic remodeling as a previously underappreciated feature of prolonged heroin abstinence and reveal a marked divergence in the molecular adaptations induced by heroin versus cocaine within the mPFC. These results implicate mitochondrial bioenergetic pathways as therapeutic targets for reducing relapse vulnerability specifically associated with opioid use disorder.

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Astrocytic D1 Dopamine-Signaling Regulates Synaptic Remodeling and Cocaine Seeking

D1-type receptor (D1R)-mediated dopaminergic signaling within the nucleus accumbens shell (NAcSh) is essential for forming adaptive circuit changes that embed persistent memories associated with drug seeking and craving. While D1R is expressed in both NAcSh neurons and astrocytes, the specific contribution of astrocytic D1R to drug-related circuit plasticity remains poorly understood. Here, we demonstrate in mouse NAcSh slices that D1R agonists increase astrocytic Ca2+ activity, an effect that is attenuated by astrocyte-specific D1R knockdown. Furthermore, selective knockdown of astrocytic D1R in the NAcSh prior to cocaine self-administration inhibits cocaine-induced generation of silent synapses, therefore hampering the associated remodeling of NAcSh circuits. Behaviorally, knockdown of NAcSh astrocytic D1R expedites the extinction of cocaine seeking and reduces cue-induced reinstatement. These results identify astrocytic D1R as a fundamental component of NAcSh dopamine signaling during cocaine experience that remodels synaptic connections and neural networks underlying drug seeking and relapse.

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A shared transcriptional network in the nucleus accumbens supports resilience to chronic stress across sex.

Although chronic stress increases the risk for depression, only a subset of exposed individuals develop psychiatric illness. The biological mechanisms that protect against depression remain incompletely understood, particularly at the molecular level. Here, we identify a transcriptional network in the nucleus accumbens (NAc), a central brain reward region, that supports stress resilience in both sexes and demonstrate the causal contribution of key hub genes. Using chronic social defeat stress, RNA-seq, and co-expression network analysis, we find sex-specific but overlapping gene modules linked to resilience, anchored by shared hub genes embedded within a common network architecture. Overexpression of these hub genes in stress-naive mice confers stress protection and induces a transcriptional state that is discrete from both susceptible and resilient profiles. These findings position resilience as a structured and targetable molecular phenotype and provide a basis for investigating sex-informed mechanisms of stress adaptation.

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Cortical astrocytes control stress resilience

BackgroundChronic stress exposure is a risk factor for several psychiatric disorders, including post-traumatic stress disorder (PTSD) and major depression (MDD), with the prefrontal cortex (PFC) playing a key role in mediating this stress susceptibility. However, most individuals who are exposed to chronic stress are resilient and do not develop psychopathology. Recent evidence suggests that glial cells, especially astrocytes, play an important role in controlling stress-induced anxiety- and depression-like behavior, yet their role in contributing to stress resilience is not understood. MethodsUsing fiber photometry, chemogenetics, and RNA-sequencing in male mice, we establish a role for PFC astrocytes in stress resilience. ResultsWe demonstrate that stress-induced increases in astrocytic calcium activity are both necessary and sufficient for resilience. Bioinformatic analysis reveals robust transcriptional responses in PFC astrocytes that differ between susceptible vs. resilient mice and are unique when compared to astrocytic transcriptional changes in other limbic regions. Comparison with human RNA-sequencing data indicates that molecular changes observed in PFC astrocytes from susceptible mice converge with gene expression changes observed in MDD patients. ConclusionsTogether, these data support targeting astrocytes as a potential therapy for negative behavioral consequences following stress exposure and reveal potential molecular mechanisms within PFC astrocytes that could contribute to depressive-like behaviors.

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Sex-Specific Induction of H3K27me1 in the Prefrontal Cortex Mediates the Enduring Effects of Early Life Stress

Early life stress (ELS) is a strong risk factor for several neurodevelopmental and psychiatric disorders and is associated with persistent molecular alterations in corticolimbic regions, including the prefrontal cortex (PFC). Here, we combined unbiased proteomics profiling and viral-mediated gene transfer to characterize the enduring epigenetic changes in the PFC of male and female mice previously exposed to ELS. We found that ELS induced sex-specific and age-dependent accumulation of monomethylation of lysine 27 at histone H3 (H3K27me1), with a transient increase in adolescent females, and a delayed but enduring effect in adult males. ELS-induced H3K27me1 accumulation in the PFC involved changes of SUZ12, a subunit of the polycomb repressive complex 2 (PRC2), which controls H3K27 methylation patterns. Indeed, expression of the catalytic domain of SUZ12, VEFS, in PFC neurons during adolescence led to sex differences in social and cognitive alterations in adulthood. Together, our results demonstrate that H3K27me1 functions as a "chromatin scar" in the PFC, where it mediates lifelong susceptibility to ELS in a sex-specific manner.

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Epigenetic editing of Cartpt promotes acquisition and extinction of cocaine memory

In classic disease models, removing a pathological insult restores homeostasis. Yet, addiction persists far beyond the period of active drug use. Cocaine abstinence induces changes in gene expression and neuronal signaling in reward-related brain regions that limit recovery during abstinence. We found that 2 weeks of abstinence increased Cartpt (cocaine- and amphetamine-regulated transcript) in the mouse nucleus accumbens and decreased repressive H3K27me3 at the Cartpt locus. While endogenous CART peptide is best described for its anorexigenic function, it is also implicated in human addiction and dopamine homeostasis. To test the causal relevance of Cartpt chromatin remodeling, we used CRISPR-based epigenetic editing tools, dCas9-FOG1 and dCas9-JMJC-ZF, to manipulate H3K27me3 at Cartpt in vivo. Enriching H3K27me3 in D1 neurons repressed Cartpt expression and augmented acquisition and extinction of cocaine preference. These results show that CRISPR epigenetic editing can recapitulate endogenous chromatin states to modulate addiction-related behavior, highlighting broad therapeutic potential of both Cartpt and epigenetic editing. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=192 SRC="FIGDIR/small/689329v1_ufig1.gif" ALT="Figure 1"> View larger version (36K): org.highwire.dtl.DTLVardef@1b84229org.highwire.dtl.DTLVardef@1ffc2d7org.highwire.dtl.DTLVardef@50cf00org.highwire.dtl.DTLVardef@1462d10_HPS_FORMAT_FIGEXP M_FIG C_FIG

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Discovery of Small Molecules and a Druggable Groove That Regulate DNA Binding and Release of the AP1 Transcription Factor DeltaFOSB

{Delta}FOSB, a member of the AP1 family of transcription factors, mediates long-term neuroadaptations underlying drug addiction, seizure-related cognitive decline, dyskinesias, and several other chronic conditions. AP1 transcription factors are notoriously difficult to modulate pharmacologically due to the absence of well-defined binding pockets. Here, we identify a novel site on {Delta}FOSB, located outside the DNA-binding cleft, that accommodates small molecules. We show that sulfonic acid-containing compounds bind to this site via an induced-fit mechanism, reorienting side chains critical for DNA binding, and that they may hinder the {Delta}FOSB bZIP -helix from binding to the major groove of DNA. In vivo, direct administration of one such compound, JPC0661, into the brain reduces {Delta}FOSB occupancy at genomic AP1 consensus sites by approximately 60% as determined by CUT&RUN-sequencing. These findings suggest that DNA binding and release by AP1 transcription factors can be controlled via small molecules that dock into a novel site that falls outside of the DNA-binding cleft. Minimal sequence conservation across 29 bZIP domain-containing transcription factors in this druggable groove suggests that it can be exploited to develop AP1-subunit-selective compounds. Our studies thus reveal a novel strategy to design small-molecule inhibitors of {Delta}FOSB and other members of the bZIP transcription factor family.

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Efficient in vivo pharmacological inhibition of deltaFOSB, an AP1 transcription factor, in brain

{Delta}FOSB, an unusually stable member of the AP1 family of transcription factors, mediates long-term maladaptations that play a key role in the pathogenesis of drug addiction, cognitive decline, dyskinesias, and several other chronic neurological and psychiatric conditions. We have recently identified that 2-phenoxybenzenesulfonic acid-containing compounds disrupt the binding of {Delta}FOSB to DNA in vitro in cell-based assays, and one such compound, JPC0661, disrupts {Delta}FOSB binding to genomic DNA in vivo in mouse brain with partial efficiency. JPC0661 binds to a groove outside of the DNA-binding cleft of the {Delta}FOSB/JUND bZIP heterodimer in the co-crystal structure. Here, we generated a panel of analogs of JPC0661 with the goal of establishing structure-activity relationships and improving its in vivo efficacy by replacing the amino-pyrazolone cap moiety with various substituents. We show that one such analog, YL0441, disrupts the binding of {Delta}FOSB to DNA in vitro and in vivo, and suppresses {Delta}FOSB-function in cell-based assays. Importantly, infusion of YL0441 into the hippocampus of APP mice (a mouse model for Alzheimers disease) leads to virtually complete loss of {Delta}FOSB bound to genomic DNA by CUT&RUN sequencing. Our findings corroborate that DNA binding/release of AP1 transcription factors can be controlled via small molecules, even by analogs of a compound that binds to a groove outside of the DNA-binding cleft, and that our lead can be optimized via medicinal chemistry to yield a highly efficacious inhibitor of {Delta}FOSB function in vivo. These findings define a strategy to design small-molecule inhibitors for other AP1- and AP1-related transcription factors. IN BRIEFWe demonstrate the creation of a highly effective inhibitor, YL0441, of {Delta}FOSB, an AP1 transcription factor, which decreases the number of {Delta}FOSB-bound sites to genomic DNA by [~]94% upon in vivo infusion to the hippocampus of APP mice, a mouse model for Alzheimers disease. This work generates a highly novel probe compound to assess the therapeutic value of {Delta}FOSB in vivo, a transcription factor with a critical role in mediating long-term changes in gene expression in several neuropsychiatric disorders in addition to Alzheimers disease, including drug addiction, seizure-related cognitive decline, and dyskinesias.

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{triangleup}FOSB in the nucleus accumbens core is required for increased anxiety, but not decreased social motivation, following estrogen withdrawal in female mice

During pregnancy, estrogen levels rise dramatically, but quickly drop to prepartum levels following birth, and remain suppressed until ovulation resumes. This "postpartum estrogen withdrawal" state has been linked to changes in the brain and behavior in humans and rodents. Previous research has demonstrated that following a hormone-simulated pseudopregnancy (HSP), an experimental model of postpartum estrogen withdrawal, female mice show increased anxiety-like behaviors and decreased social motivation. Further, these behavioral changes occur concurrently with an increase in {Delta}FOSB, a transcription factor associated with stable long-term plasticity, in the nucleus accumbens core. To test whether this increase in {Delta}FOSB is required for these behavioral changes, we used a viral-mediated gene transfer approach to prevent {Delta}FOSB-mediated transcription in the NAcC during HSP and found that it reduced the high-anxiety behavioral phenotype in estrogen-withdrawn females. However, preventing {Delta}FOSB-mediated transcription had little effect on social motivation. Together, these results suggest that postpartum estrogen withdrawal increases {Delta}FOSB in the NAc core to impact anxiety-like behaviors, but not social motivation, following estrogen withdrawal.

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Oxidation of ΔFOSB at Cys172 Controls Hippocampal Gene Targets and Learning

Imbalance of reduction/oxidation (redox) in the brain is associated with numerous diseases including Alzheimers disease (AD), substance abuse disorders, and stroke. Moreover, cognitive decline can be caused by neuronal dysfunction that precedes cell death, and this dysfunction is in part produced by altered gene expression. However, the mechanisms by which redox state controls gene expression in neurons are not well understood. {Delta}FOSB is a neuronally enriched transcription factor critical for orchestrating gene expression underlying memory, mood, and motivated behaviors. It is dysregulated in many conditions including AD. We showed recently that {Delta}FOSB forms a redox-sensitive disulfide bond between cysteine 172 (C172) of {Delta}FOSB and C279 of its preferred binding partner JUND. This bond works as a redox switch to control DNA-binding, based on studies of recombinant proteins in vitro. Here, we show that this redox control of {Delta}FOSB function in vitro is conserved in vivo. We show that {Delta}FOSB C172 forms a redox-sensitive disulfide bond with JUND that regulates the stability of this AP1-transcription factor complex and its binding to DNA in cells. We also validate the formation of {Delta}FOSB-containing complexes held together via disulfide bonds in mouse brain in vivo. We show that exogenous oxidative stress reduces {Delta}FOSB binding to gene targets in mouse brain and that Fosb C172S knock-in mice, which lack a functional {Delta}FOSB redox switch, are insensitive to this oxidation-dependent reduction in target gene binding, demonstrating that {Delta}FOSB is regulated by a redox switch that modulates binding to target genes in the hippocampus. Finally, we demonstrate that FosB C172S knock-in mice are less sensitive to cognitive dysfunction induced by oxidative stress. This evidence supports {Delta}FOSB as an important mediator of oxidative stress-driven changes in gene expression and cognition and implicates {Delta}FOSB as a possible therapeutic target for diseases associated with oxidative stress in the brain, including AD.

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Astrocytic CREB regulates transcriptional, neuronal, and behavioral responses to cocaine

Drug addiction is characterized by neuronal adaptations that support a shift from goal-directed behaviors to habitual, compulsive drug-seeking with persistent effects on cognition and decision-making. Emerging evidence increasingly indicates that astrocytes are also involved in nervous system disorders, including addiction, but the cocaine-induced astrocyte-specific transcriptome has not yet been investigated. We utilized whole cell sorting of astrocytes, RNA-sequencing, and bioinformatic approaches to characterize the astrocyte transcriptome in the nucleus accumbens (NAc), a key brain region involved in reward-processing, following cocaine self-administration, prolonged abstinence, and "relapse" in male mice. We found that astrocytes exhibit robust and contextually-specific transcriptional signatures that converge strongly with human cocaine use disorder. Bioinformatic analysis revealed CREB as a highly ranked predicted upstream regulator of cocaine-induced transcriptional regulation in NAc astrocytes, and CUT&RUN-sequencing mapped increased CREB binding across the astrocyte genome in response to cocaine. Viral-mediated manipulation of CREB activity selectively in NAc astrocytes, in combination with several measures of addiction-related behaviors including conditioned place preference and self-administration, revealed that astrocytic CREB increases the rewarding and reinforcing properties of cocaine. This effect is sex-specific, with no change in astrocytic CREB activity or CPP found in females. Subsequent experiments identify potential molecular mechanisms of astrocytic CREBs influence through modulating astrocytic Ca2+ signaling in response to cocaine. Finally, we show that astrocytic CREB selectively modulates D1-type medium spiny neurons in NAc to control cocaine-related behaviors. Together, these data demonstrate that the astrocyte transcriptome responds robustly to cocaine and that CREB mediates cocaines effects on gene expression in astrocytes, with consequent effects on neuronal activity and rewarding responses to the drug.

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Transcriptional Profiles in Nucleus Accumbens of Antidepressant Resistance in Chronically Stressed Mice

Treatment-resistant depression (TRD), defined by unsuccessful response to multiple antidepressants, affects approximately one-third of individuals with major depressive disorder, yet its underlying molecular mechanisms remain poorly understood. Here, we developed a preclinical model of TRD in which mice exposed to chronic social defeat stress were sequentially treated with fluoxetine (FLX) and ketamine (KET), allowing behavioral stratification into antidepressant responsive and non-responsive mice. RNA sequencing of the nucleus accumbens (NAc) and prefrontal cortex (PFC) revealed transcriptional signatures associated with treatment outcomes. Prior exposure to FLX exerted a priming effect that facilitated molecular and behavioral responsiveness to KET in a subset of animals in both the NAc and PFC. However, this priming effect was absent in non-responders, despite identical treatment regimes, suggesting a transcriptional divergence underlying differential outcomes. Gene co-expression network analysis identified modules enriched for differentially expressed genes unique to stress-susceptible and FLX-KET nonresponsive mice, as well as modules overlapping with both stress susceptibility and antidepressant resistance. These findings suggest that failed antidepressant treatment can shape the brains molecular landscape in a way that influences subsequent treatment outcomes, and that resistance arises not simply from treatment failure but from an absence of adaptive molecular priming. This work provides insight into the gene networks contributing to antidepressant non-response and highlights a mechanistic framework for modeling TRD in preclinical systems. By identifying molecular correlates of sequential pharmacological resistance, our findings may inform the development of novel therapeutic strategies for individuals with TRD.

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A meta-analysis of the effects of early life stress on the prefrontal cortex transcriptome suggests long-term effects on myelin

BackgroundEarly life stress (ELS) refers to exposure to negative childhood experiences, such as neglect, disaster, and physical, mental, or emotional abuse. ELS can permanently alter the brain, leading to cognitive impairment, increased sensitivity to future stressors, and mental health risks. The prefrontal cortex (PFC) is a key brain region implicated in the effects of ELS. MethodsTo better understand the effects of ELS on the PFC, we ran a meta-analysis of publicly available transcriptional profiling datasets. We identified five datasets (GSE89692, GSE116416, GSE14720, GSE153043, GSE124387) that characterized the long-term effects of multi-day postnatal ELS paradigms (maternal separation, limited nesting/bedding) in male and female laboratory rodents (rats, mice). The outcome variable was gene expression in the PFC later in adulthood as measured by microarray or RNA-Seq. To conduct the meta-analysis, preprocessed gene expression data were extracted from the Gemma database. Following quality control, the final sample size was n=89: n=42 controls & n=47 ELS: GSE116416 n=23 (no outliers); GSE116416 n=44 (2 outliers); GSE14720 n=7 (no outliers); GSE153043 n=9 (1 outlier), and GSE124387 n=6 (no outliers). Differential expression was calculated using the limma pipeline followed by an empirical Bayes correction. For each gene, a random effects meta-analysis model was then fit to the ELS vs. Control effect sizes (Log2 Fold Changes) from each study. ResultsOur meta-analysis yielded stable estimates for 11,885 genes, identifying five genes with differential expression following ELS (false discovery rate< 0.05): transforming growth factor alpha (Tgfa), IQ motif containing GTPase activating protein 3 (Iqgap3), collagen, type XI, alpha 1 (Col11a1), claudin 11 (Cldn11) and myelin associated glycoprotein (Mag), all of which were downregulated. Broadly, gene sets associated with oligodendrocyte differentiation, myelination, and brain development were downregulated following ELS. In contrast, genes previously shown to be upregulated in Major Depressive Disorder patients were upregulated following ELS. ConclusionThese findings suggest that ELS during critical periods of development may produce long-term effects on the efficiency of transmission in the PFC and drive changes in gene expression similar to those underlying depression. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=101 SRC="FIGDIR/small/624315v1_ufig1.gif" ALT="Figure 1"> View larger version (22K): org.highwire.dtl.DTLVardef@1619926org.highwire.dtl.DTLVardef@8da510org.highwire.dtl.DTLVardef@14feffcorg.highwire.dtl.DTLVardef@114aae3_HPS_FORMAT_FIGEXP M_FIG C_FIG Key PointsO_LIEarly life stress (ELS) can have long-term effects on the prefrontal cortex (PFC) and its related cognitive and emotional functions. C_LIO_LITo elucidate these long-term effects, we conducted a meta-analysis of five publicly available PFC transcriptional profiling datasets from adult rodents that had previously experienced ELS. C_LIO_LIThis meta-analysis revealed a consistent downregulation of myelin-related genes in the PFC following ELS, and an upregulation of genes related to Major Depressive Disorder. C_LI Plain Language SummaryEarly life stress refers to exposure to negative childhood experiences, such as neglect, disaster, and physical, mental, or emotional abuse. Early life stress can permanently alter the brain, including the prefrontal cortex, which can lead to cognitive and emotional dysfunction that lasts into adulthood. We performed a meta-analysis using five public datasets to identify consistent long-term effects of early life stress on gene expression (mRNA) in the prefrontal cortex of adult rodents. In these studies, rodents that had experienced early life stress consistently showed a decreased amount of mRNA for genes related to myelin. Myelin is the fatty layer that insulates the axons of neurons, allowing them to transmit electrical signals more efficiently. These gene expression changes may suggest long-term effects of early life stress on the efficiency of prefrontal neurotransmission, disrupting cognitive and emotional processing.

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Decoding the transcriptomic signatures of psychological trauma in human cortex and amygdala

Psychological trauma has profound effects on brain function and precipitates psychiatric disorders in vulnerable individuals, however, the molecular mechanisms linking trauma with psychiatric risk remain incompletely understood. Using RNA-seq data postmortem brain tissue of a cohort of 304 donors (N=136 with trauma exposure), we investigated transcriptional signatures of trauma exposures in two cortical regions (dorsolateral prefrontal cortex, and dorsal anterior cingulate cortex) and two amygdala regions (medial amygdala and basolateral amygdala) associated with stress processing and regulation. We focused on dissecting heterogeneity of traumatic experiences in these transcriptional signatures by investigating exposure to several trauma types (childhood, adulthood, complex, single acute, combat, and interpersonal traumas) and interactions with sex. Overall, amygdala regions were more vulnerable to childhood traumas, whereas cortical regions were more vulnerable to adulthood trauma (regardless of childhood experience). Using cell-type-specific expression imputation, we identified a strong transcriptional response of medial amygdala excitatory neurons to childhood trauma, which coincided with dysregulation observed in a human induced pluripotent stem cell (hiPSC)-derived glutamatergic neurons exposed to hydrocortisone. We resolved multiscale coexpression networks for each brain region and identified modules enriched in trauma signatures and whose connectivity was altered with trauma. Trauma-associated coexpression modules provide insight into coordinated functional dysregulation with different traumas and point to potential gene targets for further dissection. Together, these data provide a characterization of the long-lasting human encoding of traumatic experiences in corticolimbic regions of human brain.

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Temporal Dynamics of Nucleus Accumbens Neurons in Male Mice During Reward Seeking

The nucleus accumbens (NAc) regulates reward-motivated behavior, but the temporal dynamics of NAc neurons that enable "free-willed" animals to obtain rewards remain elusive. Here, we recorded Ca2+ activity from individual NAc neurons when mice performed self-paced lever-presses for sucrose. NAc neurons exhibited three temporally-sequenced clusters, defined by times at which they exhibited increased Ca2+ activity: approximately 0, -2.5 or -5 sec relative to the lever-pressing. Dopamine D1 receptor (D1)-expressing neurons and D2-neurons formed the majority of the -5-sec versus -2.5-sec clusters, respectively, while both neuronal subtypes were represented in the 0-sec cluster. We found that pre-press activity patterns of D1- or D2-neurons could predict subsequent lever-presses. Inhibiting D1-neurons at -5 sec or D2-neurons at -2.5 sec, but not at other timepoints, reduced sucrose-motivated lever-pressing. We propose that the time-specific activity of D1- and D2-neurons mediate key temporal features of the NAc through which reward motivation initiates reward-seeking behavior.

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Cell-Type-Specific Regulation of Cocaine Reward by the E2F3a Transcription Factor in Nucleus Accumbens

The development of drug addiction is characterized by molecular changes in brain reward regions that lead to the transition from recreational to compulsive drug use. These neurobiological processes in brain reward regions, such as the nucleus accumbens (NAc), are orchestrated in large part by transcriptional regulation. Our group recently identified the transcription factor E2F3a as a novel regulator of cocaines rewarding effects and gene expression regulation in the NAc of male mice. Despite this progress, no information is available about the role of E2F3a in regulating cocaine reward at the sex- and cell-specific levels. Here, we used male and female mice expressing Cre-recombinase in either D1- or D2-type medium spiny neurons (MSNs) combined with viral-mediated gene transfer to bidirectionally control levels of E2F3a in a cell-type-specific manner in the NAc during conditioned place preference (CPP) to cocaine. Our findings show that selective overexpression of E2F3a in D1-MSNs increased cocaine CPP in both male and female mice, whereas opposite effects were observed under knockdown conditions. In contrast, equivalent E2F3a manipulations in D2-MSNs had no significant effects. To further explore the role of E2F3a in sophisticated operant and motivated behaviors, we performed viral manipulations of all NAc neurons in combination with cocaine self-administration and behavioral economics procedures in rats and demonstrated that E2F3a regulates sensitivity aspects of cocaine seeking and taking. These results confirm E2F3a as a central substrate of cocaine reward and demonstrate that this effect is mediated in D1-MSNs, thereby providing increased knowledge of cocaine action at the transcriptional level.

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Cocaine-Induced Gene Regulation in D1 and D2 Neuronal Ensembles of the Nucleus Accumbens Revealed by Single-Cell RNA Sequencing

Cocaine use disorder is characterized by persistent drug-seeking behavior and a high risk of relapse, driven by lasting molecular and circuit adaptations in the nucleus accumbens. To explore the transcriptomic changes underlying these alterations, we employed fluorescence-activated nucleus sorting coupled with single-nucleus RNA sequencing to analyze D1 and D2 medium spiny neurons in this brain region of male mice subjected to acute cocaine exposure or to prolonged withdrawal from repeated cocaine exposure without or with an acute cocaine rechallenge. This approach allowed us to precisely delineate and contrast transcriptionally distinct neuronal subpopulations[boxh]or ensembles - across various treatment conditions. We identified significant heterogeneity within both D1 and D2 MSNs, revealing distinct clusters with unique transcriptional profiles. Notably, we identified a discrete D1 MSN population characterized by the upregulation of immediate early genes, as well as another group of D1 MSNs linked to prolonged withdrawal, uncovering novel regulators of withdrawal-related transcriptome dynamics. Our findings provide a high-resolution transcriptomic map of D1 and D2 MSNs, illustrating the dynamic changes induced by cocaine exposure and withdrawal. These insights into the molecular mechanisms underlying cocaine use disorder highlight potential targets for therapeutic intervention aimed at preventing relapse.

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Activity-dependent FosB gene expression negatively regulates mast cell functions.

Mast cells are innate immune cells that regulate physiological processes by releasing pre-stored and newly synthesized mediators in response to allergens, infection, and other stimuli. Dysregulated mast cell activity can lead to multisystemic pathologies, but the underlying regulatory mechanisms remain poorly understood. We found that FOSB and {Delta}FOSB, transcription factors encoded by the FosB gene, are robustly expressed in mast cells following IgE-antigen stimulation, suggesting a role in modulating stimulus-induced mast cell functions. Using phenotypic, gene binding, and gene expression analyses in wild-type and mast cell-specific FosB knockout male mice, we demonstrate that FOSB/{Delta}FOSB modulates mast cell functions by limiting reactivity to allergen-like stimuli both in vitro and in vivo. These effects seem to be mediated, at least in part, by FOSB/{Delta}FOSB-driven enhanced expression of DUSP4, a dual-specificity phosphatase that attenuates MAPK signaling. These findings highlight FOSB/{Delta}FOSB as critical regulators of mast cell activity and potential targets for therapeutic intervention. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=118 SRC="FIGDIR/small/592755v2_ufig1.gif" ALT="Figure 1"> View larger version (48K): org.highwire.dtl.DTLVardef@190be2corg.highwire.dtl.DTLVardef@1b53f9borg.highwire.dtl.DTLVardef@631997org.highwire.dtl.DTLVardef@250bc7_HPS_FORMAT_FIGEXP M_FIG C_FIG

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