RESUMEN
Repeated cocaine use produces adaptations in brain function that contribute to long-lasting behaviors associated with cocaine use disorder (CUD). In rodents, the activity-regulated cytoskeleton-associated protein (Arc) can regulate glutamatergic synaptic transmission, and cocaine regulates Arc expression and subcellular localization in multiple brain regions, including the nucleus accumbens (NAc)-a brain region linked to CUD-related behavior. We show here that repeated, non-contingent cocaine administration in global Arc KO male mice produced a dramatic hypersensitization of cocaine locomotor responses and drug experience-dependent sensitization of conditioned place preference (CPP). In contrast to the global Arc KO mice, viral-mediated reduction of Arc in the adult male, but not female, NAc (shArcNAc) reduced both CPP and cocaine-induced locomotor activity, but without altering basal miniature or evoked glutamatergic synaptic transmission. Interestingly, cell type-specific knockdown of Arc in D1 dopamine receptor-expressing NAc neurons reduced cocaine-induced locomotor sensitization, but not cocaine CPP; whereas, Arc knockdown in D2 dopamine receptor-expressing NAc neurons reduced cocaine CPP, but not cocaine-induced locomotion. Taken together, our findings reveal that global, developmental loss of Arc produces hypersensitized cocaine responses; however, these effects cannot be explained by Arc's function in the adult mouse NAc since Arc is required in a cell type- and sex-specific manner to support cocaine-context associations and locomotor responses.
Asunto(s)
Cocaína , Proteínas del Citoesqueleto , Proteínas del Tejido Nervioso , Núcleo Accumbens , Animales , Núcleo Accumbens/metabolismo , Núcleo Accumbens/efectos de los fármacos , Proteínas del Citoesqueleto/genética , Proteínas del Citoesqueleto/metabolismo , Masculino , Ratones , Femenino , Cocaína/farmacología , Proteínas del Tejido Nervioso/genética , Proteínas del Tejido Nervioso/metabolismo , Receptores de Dopamina D1/metabolismo , Receptores de Dopamina D1/genética , Locomoción/efectos de los fármacos , Trastornos Relacionados con Cocaína/metabolismo , Trastornos Relacionados con Cocaína/genética , Trastornos Relacionados con Cocaína/fisiopatología , Ratones Endogámicos C57BL , Neuronas/metabolismo , Neuronas/efectos de los fármacos , Transmisión SinápticaRESUMEN
Orchestrating complex behaviors, such as approaching and consuming food, is critical for survival. In addition to hypothalamus neuronal circuits, the nucleus accumbens (NAc) also controls appetite and satiety. However, specific neuronal subtypes of the NAc that are involved and how the humoral and neuronal signals coordinate to regulate feeding remain incompletely understood. Here we decipher the spatial diversity of neuron subtypes of the NAc shell (NAcSh) and define a dopamine receptor D1-expressing and Serpinb2-expressing subtype controlling food consumption in male mice. Chemogenetics and optogenetics-mediated regulation of Serpinb2+ neurons bidirectionally regulate food seeking and consumption specifically. Circuitry stimulation reveals that the NAcShSerpinb2âLHLepR projection controls refeeding and can overcome leptin-mediated feeding suppression. Furthermore, NAcSh Serpinb2+ neuron ablation reduces food intake and upregulates energy expenditure, resulting in reduced bodyweight gain. Our study reveals a neural circuit consisting of a molecularly distinct neuronal subtype that bidirectionally regulates energy homeostasis, providing a potential therapeutic target for eating disorders.
Asunto(s)
Metabolismo Energético , Conducta Alimentaria , Homeostasis , Neuronas , Núcleo Accumbens , Animales , Núcleo Accumbens/metabolismo , Ratones , Masculino , Neuronas/metabolismo , Ingestión de Alimentos/fisiología , Receptores Dopaminérgicos/metabolismo , Receptores de Dopamina D1/metabolismo , Receptores de Dopamina D1/genéticaRESUMEN
Recent work demonstrated that activation of spinal D1 and D5 dopamine receptors (D1/D5Rs) facilitates non-Hebbian long-term potentiation (LTP) at primary afferent synapses onto spinal projection neurons. However, the cellular localization of the D1/D5Rs driving non-Hebbian LTP in spinal nociceptive circuits remains unknown, and it is also unclear whether D1/D5R signaling must occur concurrently with sensory input in order to promote non-Hebbian LTP at these synapses. Here we investigate these issues using cell-type-selective knockdown of D1Rs or D5Rs from lamina I spinoparabrachial neurons, dorsal root ganglion (DRG) neurons, or astrocytes in adult mice of either sex using Cre recombinase-based genetic strategies. The LTP evoked by low-frequency stimulation of primary afferents in the presence of the selective D1/D5R agonist SKF82958 persisted following the knockdown of D1R or D5R in spinoparabrachial neurons, suggesting that postsynaptic D1/D5R signaling was dispensable for non-Hebbian plasticity at sensory synapses onto these key output neurons of the superficial dorsal horn (SDH). Similarly, the knockdown of D1Rs or D5Rs in DRG neurons failed to influence SKF82958-enabled LTP in lamina I projection neurons. In contrast, SKF82958-induced LTP was suppressed by the knockdown of D1R or D5R in spinal astrocytes. Furthermore, the data indicate that the activation of D1R/D5Rs in spinal astrocytes can either retroactively or proactively drive non-Hebbian LTP in spinoparabrachial neurons. Collectively, these results suggest that dopaminergic signaling in astrocytes can strongly promote activity-dependent LTP in the SDH, which is predicted to significantly enhance the amplification of ascending nociceptive transmission from the spinal cord to the brain.
Asunto(s)
Astrocitos , Potenciación a Largo Plazo , Receptores de Dopamina D1 , Receptores de Dopamina D5 , Sinapsis , Animales , Receptores de Dopamina D1/metabolismo , Receptores de Dopamina D1/agonistas , Receptores de Dopamina D1/genética , Potenciación a Largo Plazo/fisiología , Astrocitos/metabolismo , Astrocitos/fisiología , Ratones , Masculino , Receptores de Dopamina D5/metabolismo , Receptores de Dopamina D5/agonistas , Receptores de Dopamina D5/genética , Femenino , Sinapsis/fisiología , Sinapsis/metabolismo , Ganglios Espinales/citología , Asta Dorsal de la Médula Espinal/metabolismo , Asta Dorsal de la Médula Espinal/citología , Ratones Transgénicos , Ratones Endogámicos C57BLRESUMEN
Synaptic plasticity in the mesolimbic dopamine (DA) system contributes to the neural adaptations underlying addictive behaviors and relapse. However, the specific behavioral relevance of glutamatergic excitatory drive onto dopamine D1 receptor (D1R)-expressing neurons in mediating the reinforcing effect of cocaine remains unclear. Here, we investigated how midbrain AMPAR and NMDAR function modulate cocaine reward-related behavior using mutant mouse lines lacking the glutamate receptor genes Gria1 or Grin1 in D1R-expressing neurons (GluA1D1CreERT2 or GluN1D1CreERT2, respectively). We found that conditional genetic deletion of either GluA1 or GluN1 within this neuronal sub-population did not impact the ability of acute cocaine injection to increase intracranial self-stimulation (ICSS) ratio or reduced brain reward threshold compared to littermate controls. Additionally, our data demonstrate that deletion of GluA1 and GluN1 receptor subunits within D1R-expressing neurons did not affect cocaine reinforcement in an operant self-administration paradigm, as mutant mice showed comparable cocaine responses and intake to controls. Given the pivotal role of glutamate receptors in mediating relapse behavior, we further explored the impact of genetic deletion of AMPAR and NMDAR onto D1R-expressing neurons on cue-induced reinstatement following extinction. Surprisingly, deletion of AMPAR and NMDAR onto these neurons did not impair cue-induced reinstatement of cocaine-seeking behavior. These findings suggest that glutamatergic activity via NMDAR and AMPAR in D1R-expressing neurons may not exclusively mediate the reinforcing effects of cocaine and cue-induced reinstatement.
Asunto(s)
Cocaína , Receptores AMPA , Receptores de Dopamina D1 , Receptores de N-Metil-D-Aspartato , Recompensa , Autoadministración , Animales , Cocaína/farmacología , Cocaína/administración & dosificación , Receptores de N-Metil-D-Aspartato/genética , Receptores de N-Metil-D-Aspartato/metabolismo , Receptores AMPA/genética , Receptores AMPA/metabolismo , Receptores de Dopamina D1/genética , Receptores de Dopamina D1/metabolismo , Ratones , Masculino , Mesencéfalo/metabolismo , Mesencéfalo/efectos de los fármacos , Condicionamiento Operante/efectos de los fármacos , Condicionamiento Operante/fisiología , Neuronas/metabolismo , Neuronas/efectos de los fármacos , Ratones Noqueados , Inhibidores de Captación de Dopamina/farmacología , Ratones Endogámicos C57BL , Refuerzo en Psicología , Proteínas del Tejido NerviosoRESUMEN
Gap junctions are channels that allow for direct transmission of electrical signals between cells. However, the ability of one cell to be impacted or controlled by other cells through gap junctions remains unclear. In this study, heterocellular coupling between ON α retinal ganglion cells (α-RGCs) and displaced amacrine cells (ACs) in the mouse retina was used as a model. The impact of the extent of coupling of interconnected ACs on the synchronized firing between coupled ON α-RGC-AC pair was investigated using the dopamine 1 receptor (D1R) antagonist-SCH23390 and agonist-SKF38393. It was observed that the synchronized firing between the ON α-RGC-ACs pairs was increased by the D1R antagonist SCH23390, whereas it was eradicated by the agonist SKF38393. Subsequently, the signaling drive was investigated by infecting coupled ON α-RGC-AC pairs with the channelrhodopsin-2(ChR2) mutation L132C engineered to enhance light sensitivities. The results demonstrated that the spikes of ON α-RGCs (without ChR2) could be triggered by ACs (with ChR2) through the gap junction, and vice versa. Furthermore, it was observed that ON α-RGCs stimulated with 3-10 Hz currents by whole cell patch could elicit synchronous spikes in the coupled ACs, and vice versa. This provided direct evidence that the firing of one cell could be influenced by another cell through gap junctions. However, this phenomenon was not observed between OFF α-RGC pairs. The study implied that the synchronized firing between ON α-RGC-AC pairs could potentially be affected by the coupling of interconnected ACs. Additionally, one cell type could selectively control the firing of another cell type, thereby forcefully transmitting information. The key role of gap junctions in synchronizing firing and driving cells between α-RGCs and coupled ACs in the mouse retina was highlighted.NEW & NOTEWORTHY This study investigates the role of gap junctions in transmitting electrical signals between cells and their potential for cell control. Using ON α retinal ganglion cells (α-RGCs) and amacrine cells (ACs) in the mouse retina, the researchers find that the extent of coupling between ACs affects synchronized firing. Bidirectional signaling occurs between ACs and ON α-RGCs through gap junctions.
Asunto(s)
Potenciales de Acción , Células Amacrinas , Uniones Comunicantes , Células Ganglionares de la Retina , Animales , Células Amacrinas/metabolismo , Células Amacrinas/fisiología , Células Amacrinas/efectos de los fármacos , Células Ganglionares de la Retina/metabolismo , Células Ganglionares de la Retina/fisiología , Ratones , Uniones Comunicantes/metabolismo , Uniones Comunicantes/efectos de los fármacos , Potenciales de Acción/efectos de los fármacos , Ratones Endogámicos C57BL , Retina/metabolismo , Retina/fisiología , 2,3,4,5-Tetrahidro-7,8-dihidroxi-1-fenil-1H-3-benzazepina/farmacología , Receptores de Dopamina D1/metabolismo , Receptores de Dopamina D1/genética , Receptores de Dopamina D1/agonistas , Comunicación Celular/fisiología , Masculino , Channelrhodopsins/metabolismo , Channelrhodopsins/genéticaRESUMEN
Alloparenting refers to the practice of caring for the young by individuals other than their biological parents. The relationship between the dynamic changes in psychological functions underlying alloparenting and the development of specific neuroreceptors remains unclear. Using a classic 10-day pup sensitization procedure, together with a pup preference and pup retrieval test on the EPM (elevated plus maze), we showed that both male and female adolescent rats (24 days old) had significantly shorter latency than adult rats (65 days old) to be alloparental, and their motivation levels for pups and objects were also significantly higher. In contrast, adult rats retrieved more pups than adolescent rats even though they appeared to be more anxious on the EPM. Analysis of mRNA expression using real-time-PCR revealed a higher dopamine D2 receptor (DRD2) receptor expression in adult hippocampus, amygdala, and ventral striatum, along with higher dopamine D1 receptor (DRD1) receptor expression in ventral striatum compared to adolescent rats. Adult rats also showed significantly higher levels of 5-hydroxytryptamine receptor 2A (HTR2A) receptor expression in the medial prefrontal cortex, amygdala, ventral striatum, and hypothalamus. These results suggest that the faster onset of alloparenting in adolescent rats compared to adult rats, along with the psychological functions involved, may be mediated by varying levels of dopamine DRD1, DRD2, and HTR2A in different forebrain regions.
Asunto(s)
Prosencéfalo , ARN Mensajero , Receptor de Serotonina 5-HT2A , Receptores de Dopamina D1 , Receptores de Dopamina D2 , Animales , Receptores de Dopamina D2/metabolismo , Receptores de Dopamina D2/genética , Masculino , Ratas , Femenino , Receptores de Dopamina D1/metabolismo , Receptores de Dopamina D1/genética , ARN Mensajero/metabolismo , ARN Mensajero/genética , Receptor de Serotonina 5-HT2A/metabolismo , Receptor de Serotonina 5-HT2A/genética , Prosencéfalo/metabolismo , Empatía/fisiología , Factores de Edad , Caracteres Sexuales , Ratas Sprague-Dawley , Conducta Animal/fisiología , Amígdala del Cerebelo/metabolismoRESUMEN
Declining estrogen (E2) leads to physical inactivity and adipose tissue (AT) dysfunction. Mechanisms are not fully understood, but E2's effects on dopamine (DA) activity in the nucleus accumbens (NAc) brain region may mediate changes in mood and voluntary physical activity (PA). Our prior work revealed that loss of E2 robustly affected NAc DA-related gene expression, and the pattern correlated with sedentary behavior and visceral fat. The current study used a new transgenic mouse model (D1ERKO) to determine whether the abolishment of E2 receptor alpha (ERα) signaling within DA-rich brain regions affects PA and AT metabolism. Adult male and female wild-type (WT) and D1ERKO (KD) mice were assessed for body composition, energy intake (EE), spontaneous PA (SPA), and energy expenditure (EE); underwent glucose tolerance testing; and were assessed for blood biochemistry. Perigonadal white AT (PGAT), brown AT (BAT), and NAc brain regions were assessed for genes and proteins associated with DA, E2 signaling, and metabolism; AT sections were also assessed for uncoupling protein (UCP1). KD mice had greater lean mass and EE (genotype effects) and a visible change in BAT phenotype characterized by increased UCP1 staining and lipid depletion, an effect seen only among females. Female KD had higher NAc Oprm1 transcript levels and greater PGAT UCP1. This group tended to have improved glucose tolerance (p = 0.07). NAc suppression of Esr1 does not appear to affect PA, yet it may directly affect metabolism. This work may lead to novel targets to improve metabolic dysfunction following E2 loss, possibly by targeting the NAc.
Asunto(s)
Tejido Adiposo , Metabolismo Energético , Receptor alfa de Estrógeno , Núcleo Accumbens , Receptores de Dopamina D1 , Animales , Femenino , Masculino , Ratones , Tejido Adiposo/metabolismo , Tejido Adiposo Pardo/metabolismo , Encéfalo/metabolismo , Receptor alfa de Estrógeno/metabolismo , Receptor alfa de Estrógeno/genética , Técnicas de Silenciamiento del Gen , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Transgénicos , Núcleo Accumbens/metabolismo , Receptores de Dopamina D1/metabolismo , Receptores de Dopamina D1/genética , Proteína Desacopladora 1/metabolismo , Proteína Desacopladora 1/genéticaRESUMEN
Motherhood is a costly life-history transition accompanied by behavioral and neural plasticity necessary for offspring care. Motherhood in the monogamous prairie vole is associated with decreased pair bond strength, suggesting a trade-off between parental investment and pair bond maintenance. Neural mechanisms governing pair bonds and maternal bonds overlap, creating possible competition between the two. We measured mRNA expression of genes encoding receptors for oxytocin (oxtr), dopamine (d1r and d2r), mu-opioids (oprm1a), and kappa-opioids (oprk1a) within three brain areas processing salience of sociosensory cues (anterior cingulate cortex; ACC), pair bonding (nucleus accumbens; NAc), and maternal care (medial preoptic area; MPOA). We compared gene expression differences between pair bonded prairie voles that were never pregnant, pregnant (~day 16 of pregnancy), and recent mothers (day 3 of lactation). We found greater gene expression in the NAc (oxtr, d2r, oprm1a, and oprk1a) and MPOA (oxtr, d1r, d2r, oprm1a, and oprk1a) following the transition to motherhood. Expression for all five genes in the ACC was greatest for females that had been bonded for longer. Gene expression within each region was highly correlated, indicating that oxytocin, dopamine, and opioids comprise a complimentary gene network for social signaling. ACC-NAc gene expression correlations indicated that being a mother (oxtr and d1r) or maintaining long-term pair bonds (oprm1a) relies on the coordination of different signaling systems within the same circuit. Our study suggests the maternal brain undergoes changes that prepare females to face the trade-off associated with increased emotional investment in offspring, while also maintaining a pair bond.
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Arvicolinae , Conducta Materna , Núcleo Accumbens , Apareamiento , Receptores Opioides mu , Animales , Femenino , Arvicolinae/genética , Receptores Opioides mu/genética , Receptores Opioides mu/metabolismo , Conducta Materna/fisiología , Núcleo Accumbens/metabolismo , Embarazo , Receptores de Oxitocina/genética , Receptores de Oxitocina/metabolismo , Receptores Opioides kappa/genética , Receptores Opioides kappa/metabolismo , Giro del Cíngulo/metabolismo , Área Preóptica/metabolismo , Receptores de Dopamina D1/genética , Receptores de Dopamina D1/metabolismoRESUMEN
Loss-of-function mutations of the gene encoding the trafficking protein particle complex subunit 9 (Trappc9) cause autosomal recessive intellectual disability and obesity by unknown mechanisms. Genome-wide analysis links Trappc9 to nonalcoholic fatty liver disease (NAFLD). Trappc9-deficient mice have been shown to appear overweight shortly after weaning. Here, we analyzed serum biochemistry and histology of adipose and liver tissues to determine the incidence of obesity and NAFLD in Trappc9-deficient mice and combined transcriptomic and proteomic analyses, pharmacological studies, and biochemical and histological examinations of postmortem mouse brains to unveil mechanisms involved. We found that Trappc9-deficient mice presented with systemic glucose homeostatic disturbance, obesity, and NAFLD, which were relieved upon chronic treatment combining dopamine receptor D2 (DRD2) agonist quinpirole and DRD1 antagonist SCH23390. Blood glucose homeostasis in Trappc9-deficient mice was restored upon administering quinpirole alone. RNA-sequencing analysis of DRD2-containing neurons and proteomic study of brain synaptosomes revealed signs of impaired neurotransmitter secretion in Trappc9-deficient mice. Biochemical and histological studies of mouse brains showed that Trappc9-deficient mice synthesized dopamine normally, but their dopamine-secreting neurons had a lower abundance of structures for releasing dopamine in the striatum. Our study suggests that Trappc9 loss of function causes obesity and NAFLD by constraining dopamine synapse formation.
Asunto(s)
Dopamina , Ratones Noqueados , Animales , Ratones , Dopamina/metabolismo , Receptores de Dopamina D2/metabolismo , Receptores de Dopamina D2/genética , Obesidad/metabolismo , Obesidad/genética , Encéfalo/metabolismo , Encéfalo/patología , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Enfermedad del Hígado Graso no Alcohólico/genética , Enfermedad del Hígado Graso no Alcohólico/tratamiento farmacológico , Enfermedad del Hígado Graso no Alcohólico/patología , Masculino , Proteínas de Transporte Vesicular/genética , Proteínas de Transporte Vesicular/metabolismo , Benzazepinas/farmacología , Benzazepinas/uso terapéutico , Receptores de Dopamina D1/metabolismo , Receptores de Dopamina D1/genética , Modelos Animales de Enfermedad , Transmisión Sináptica/efectos de los fármacosRESUMEN
Spiny projection neurons (SPNs) of the striatum are critical in integrating neurochemical information to coordinate motor and reward-based behavior. Mutations in the regulatory transcription factors expressed in SPNs can result in neurodevelopmental disorders (NDDs). Paralogous transcription factors Foxp1 and Foxp2, which are both expressed in the dopamine receptor 1 (D1) expressing SPNs, are known to have variants implicated in NDDs. Utilizing mice with a D1-SPN-specific loss of Foxp1, Foxp2, or both and a combination of behavior, electrophysiology, and cell-type-specific genomic analysis, loss of both genes results in impaired motor and social behavior as well as increased firing of the D1-SPNs. Differential gene expression analysis implicates genes involved in autism risk, electrophysiological properties, and neuronal development and function. Viral-mediated re-expression of Foxp1 into the double knockouts is sufficient to restore electrophysiological and behavioral deficits. These data indicate complementary roles between Foxp1 and Foxp2 in the D1-SPNs.
Asunto(s)
Cuerpo Estriado , Factores de Transcripción Forkhead , Animales , Factores de Transcripción Forkhead/metabolismo , Factores de Transcripción Forkhead/genética , Ratones , Cuerpo Estriado/metabolismo , Proteínas Represoras/metabolismo , Proteínas Represoras/genética , Ratones Noqueados , Receptores de Dopamina D1/metabolismo , Receptores de Dopamina D1/genética , Masculino , Neuronas/metabolismo , Ratones Endogámicos C57BL , Conducta SocialRESUMEN
As a global problem, fine particulate matter (PM2.5) really needs local fixes. Considering the increasing epidemiological relevance to anxiety and depression but inconsistent toxicological results, the most important question is to clarify whether and how PM2.5 causally contributes to these mental disorders and which components are the most dangerous for crucial mitigation in a particular place. In the present study, we chronically subjected male mice to a real-world PM2.5 exposure system throughout the winter heating period in a coal combustion area and revealed that PM2.5 caused anxiety and depression-like behaviors in adults such as restricted activity, diminished exploratory interest, enhanced repetitive stereotypy, and elevated acquired immobility, through behavioral tests including open field, elevated plus maze, marble-burying, and forced swimming tests. Importantly, we found that dopamine signaling was perturbed using mRNA transcriptional profile and bioinformatics analysis, with Drd1 as a potential target. Subsequently, we developed the Drd1 expression-directed multifraction isolating and nontarget identifying framework and identified a total of 209 compounds in PM2.5 organic extracts capable of reducing Drd1 expression. Furthermore, by applying hierarchical characteristic fragment analysis and molecular docking and dynamics simulation, we clarified that phenyl-containing compounds competitively bound to DRD1 and interfered with dopamine signaling, thereby contributing to mental disorders. Taken together, this work provides experimental evidence for researchers and clinicians to identify hazardous factors in PM2.5 and prevent adverse health outcomes and for local governments and municipalities to control source emissions for diminishing specific disease burdens.
Asunto(s)
Ansiedad , Depresión , Material Particulado , Receptores de Dopamina D1 , Animales , Material Particulado/toxicidad , Ratones , Masculino , Ansiedad/metabolismo , Depresión/metabolismo , Receptores de Dopamina D1/metabolismo , Receptores de Dopamina D1/genética , Contaminantes Atmosféricos/toxicidad , Conducta Animal/efectos de los fármacos , Simulación del Acoplamiento MolecularRESUMEN
BACKGROUND: Major depression and anxiety disorders are significant causes of disability and socioeconomic burden. Despite the prevalence and considerable impact of these affective disorders, their pathophysiology remains elusive. Thus, there is an urgent need to develop novel therapeutics for these conditions. We evaluated the role of SIRT1 in regulating dysfunctional processes of reward by using chronic social defeat stress to induce depression- and anxiety-like behaviors. Chronic social defeat stress induces physiological and behavioral changes that recapitulate depression-like symptomatology and alters gene expression programs in the nucleus accumbens, but cell type-specific changes in this critical structure remain largely unknown. METHODS: We examined transcriptional profiles of D1-expressing medium spiny neurons (MSNs) lacking deacetylase activity of SIRT1 by RNA sequencing in a cell type-specific manner using the RiboTag line of mice. We analyzed differentially expressed genes using gene ontology tools including SynGO and EnrichR and further demonstrated functional changes in D1-MSN-specific SIRT1 knockout (KO) mice using electrophysiological and behavioral measurements. RESULTS: RNA sequencing revealed altered transcriptional profiles of D1-MSNs lacking functional SIRT1 and showed specific changes in synaptic genes including glutamatergic and GABAergic (gamma-aminobutyric acidergic) receptors in D1-MSNs. These molecular changes may be associated with decreased excitatory and increased inhibitory neural activity in Sirt1 KO D1-MSNs, accompanied by morphological changes. Moreover, the D1-MSN-specific Sirt1 KO mice exhibited proresilient changes in anxiety- and depression-like behaviors. CONCLUSIONS: SIRT1 coordinates excitatory and inhibitory synaptic genes to regulate the GABAergic output tone of D1-MSNs. These findings reveal a novel signaling pathway that has potential for the development of innovative treatments for affective disorders.
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Depresión , Ratones Noqueados , Núcleo Accumbens , Sirtuina 1 , Animales , Núcleo Accumbens/metabolismo , Sirtuina 1/genética , Sirtuina 1/metabolismo , Ratones , Masculino , Depresión/genética , Depresión/metabolismo , Ratones Endogámicos C57BL , Estrés Psicológico/metabolismo , Estrés Psicológico/genética , Ansiedad/genética , Ansiedad/metabolismo , Receptores de Dopamina D1/genética , Receptores de Dopamina D1/metabolismo , Derrota Social , Regulación de la Expresión Génica/genética , Conducta Animal/fisiología , Neuronas/metabolismo , Modelos Animales de EnfermedadRESUMEN
l-DOPA-induced dyskinesia (LID) is a debilitating motor side effect arising from chronic dopamine (DA) replacement therapy with l-DOPA for the treatment of Parkinson's disease. LID is associated with supersensitivity of striatal dopaminergic signaling and fluctuations in synaptic DA following each l-DOPA dose, shrinking the therapeutic window. The heterogeneous composition of the striatum, including subpopulations of medium spiny output neurons (MSNs), interneurons, and supporting cells, complicates the identification of cell(s) underlying LID. We used single-nucleus RNA sequencing (snRNA-seq) to establish a comprehensive striatal transcriptional profile during LID development. Male hemiparkinsonian mice were treated with vehicle or l-DOPA for 1, 5, or 10â d, and striatal nuclei were processed for snRNA-seq. Analyses indicated a limited population of DA D1 receptor-expressing MSNs (D1-MSNs) formed three subclusters in response to l-DOPA treatment and expressed cellular markers of activation. These activated D1-MSNs display similar transcriptional changes previously associated with LID; however, their prevalence and transcriptional behavior were differentially influenced by l-DOPA experience. Differentially expressed genes indicated acute upregulation of plasticity-related transcription factors and mitogen-activated protein kinase signaling, while repeated l-DOPA-induced synaptic remodeling, learning and memory, and transforming growth factor-ß (TGF-ß) signaling genes. Notably, repeated l-DOPA sensitized Inhba, an activin subunit of the TGF-ß superfamily, in activated D1-MSNs, and its pharmacological inhibition impaired LID development, suggesting that activin signaling may play an essential role in LID. These data suggest distinct subsets of D1-MSNs become differentially l-DOPA-responsive due to aberrant induction of molecular mechanisms necessary for neuronal entrainment, similar to processes underlying hippocampal learning and memory.
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Cuerpo Estriado , Discinesia Inducida por Medicamentos , Levodopa , Ratones Endogámicos C57BL , Animales , Levodopa/efectos adversos , Levodopa/toxicidad , Discinesia Inducida por Medicamentos/metabolismo , Masculino , Ratones , Cuerpo Estriado/metabolismo , Cuerpo Estriado/efectos de los fármacos , Receptores de Dopamina D1/metabolismo , Receptores de Dopamina D1/genética , Antiparkinsonianos/efectos adversos , Antiparkinsonianos/farmacología , Neuronas/efectos de los fármacos , Neuronas/metabolismoRESUMEN
Dopamine (DA) acts in various key neurological and physiological processes as both a neurotransmitter and circulating hormone. Over the past several decades, the DA signaling network has been shown to regulate the progression of several types of solid tumors, and considerable evidence has shown it is a druggable pathway in the cancer cell context. However, the specific activity and effect of these pathway components appears to be tissue-type and cell-context-dependent. In the present study, expression and methylation of dopamine receptor D1 (DRD1) were measured using RNA sequencing (RNAseq) and reverse transcription polymerase chain reaction (RT-PCR) in non-small cell lung cancer (NSCLC) samples, and validated using publicly available datasets, including The Cancer Genome Atlas (TCGA). In vitro and in vivo functional experiments were performed for cell proliferation and tumor growth, respectively. Mechanistic analyses of the transcriptome and kinome in DRD1-modulated cells informed further experiments, which characterized the effects on the epidermal growth factor receptor (EGFR) pathway and programmed cell death 1 ligand 1 (PD-L1) proteins. Through these experiments, we identified the DRD1 gene as a negative regulator of disease progression in NSCLC. We show that DRD1, as well as other DA pathway components, are expressed in normal human lung tissue, and that loss of DRD1 expression through promoter hypermethylation is a common feature in NSCLC patients and is associated with worse survival. At the cellular level, DRD1 affects proliferation by inhibiting the activation of EGFR and mitogen-activated protein kinase 1/2 (ERK1/2). Interestingly, we also found that DRD1 regulates the expression of PD-L1 in lung cancer cells. Taken together, these results suggest that DRD1 methylation may constitute a biomarker of poor prognosis in NSCLC patients while other components of this pathway could be targeted to improve response to EGFR- and PD-L1-targeted therapies.
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Antígeno B7-H1 , Carcinoma de Pulmón de Células no Pequeñas , Proliferación Celular , Receptores ErbB , Regulación Neoplásica de la Expresión Génica , Neoplasias Pulmonares , Receptores de Dopamina D1 , Carcinoma de Pulmón de Células no Pequeñas/genética , Carcinoma de Pulmón de Células no Pequeñas/patología , Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Humanos , Neoplasias Pulmonares/patología , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Proliferación Celular/genética , Receptores ErbB/metabolismo , Receptores ErbB/genética , Receptores de Dopamina D1/metabolismo , Receptores de Dopamina D1/genética , Línea Celular Tumoral , Animales , Antígeno B7-H1/metabolismo , Antígeno B7-H1/genética , Ratones , Metilación de ADN/genética , Ratones Desnudos , Femenino , Transducción de Señal/genéticaRESUMEN
Trace amine-associated receptor 1 (TAAR1) is an intracellular expressed G-protein-coupled receptor that is widely expressed in major dopaminergic areas and plays a crucial role in modulation of central dopaminergic neurotransmission and function. Pharmacological studies have clarified the roles of dopamine D1 receptor (D1R) in the medial prefrontal cortex (mPFC) in cognitive function and social behaviors, and chronic stress can inhibit D1R expression due to its susceptibility. Recently, we identified TAAR1 in the mPFC as a potential target for treating chronic stress-induced cognitive and social dysfunction, but whether D1R is involved in mediating the effects of TAAR1 agonist remains unclear. Combined genomics and transcriptomic studies revealed downregulation of D1R in the mPFC of TAAR1-/- mice. Molecular dynamics simulation showed that hydrogen bond, salt bridge, and Pi-Pi stacking interactions were formed between TAAR1 and D1R indicating a stable TAAR1-D1R complex structure. Using pharmacological interventions, we found that D1R antagonist disrupted therapeutic effect of TAAR1 partial agonist RO5263397 on stress-related cognitive and social dysfunction. Knockout TAAR1 in D1-type dopamine receptor-expressing neurons reproduced adverse effects of chronic stress, and TAAR1 conditional knockout in the mPFC led to similar deficits, along with downregulation of D1R expression, all of these effects were ameliorated by viral overexpression of D1R in the mPFC, suggesting the functional interaction between TAAR1 and D1R. Collectively, our data elucidate the possible molecular mechanism that D1R in the mPFC mediates the effects of TAAR1 activation on chronic stress-induced cognitive and social deficits.
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Ratones Endogámicos C57BL , Ratones Noqueados , Corteza Prefrontal , Receptores de Dopamina D1 , Receptores Acoplados a Proteínas G , Estrés Psicológico , Animales , Corteza Prefrontal/metabolismo , Corteza Prefrontal/efectos de los fármacos , Receptores Acoplados a Proteínas G/metabolismo , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/agonistas , Estrés Psicológico/metabolismo , Masculino , Receptores de Dopamina D1/metabolismo , Receptores de Dopamina D1/agonistas , Receptores de Dopamina D1/genética , Ratones , Disfunción Cognitiva/metabolismo , Disfunción Cognitiva/etiología , Conducta SocialRESUMEN
Accumulating evidence points to dysregulations of the Nucleus Accumbens (NAc) in eating disorders (ED), however its precise contribution to ED symptomatic dimensions remains unclear. Using chemogenetic manipulations in male mice, we found that activity of dopamine D1 receptor-expressing neurons of the NAc core subregion facilitated effort for a food reward as well as voluntary exercise, but decreased food intake, while D2-expressing neurons have opposite effects. These effects are congruent with D2-neurons being more active than D1-neurons during feeding while it is the opposite during running. Chronic manipulations of each subpopulations had limited effects on energy balance. However, repeated activation of D1-neurons combined with inhibition of D2-neurons biased behavior toward activity-related energy expenditure, whilst the opposite manipulations favored energy intake. Strikingly, concomitant activation of D1-neurons and inhibition of D2-neurons precipitated weight loss in anorexia models. These results suggest that dysregulations of NAc dopaminoceptive neurons might be at the core of EDs.
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Núcleo Accumbens , Receptores de Dopamina D2 , Ratones , Masculino , Animales , Núcleo Accumbens/metabolismo , Receptores de Dopamina D2/genética , Receptores de Dopamina D2/metabolismo , Neuronas/metabolismo , Receptores de Dopamina D1/genética , Receptores de Dopamina D1/metabolismo , Metabolismo EnergéticoRESUMEN
The ventral pallidum (VP) is a central hub in the reward circuitry with diverse projections that have different behavioral roles attributed mostly to the connectivity with the downstream target. However, different VP projections may represent, as in the striatum, separate neuronal populations that differ in more than just connectivity. In this study, we performed in mice of both sexes a multimodal dissection of four major projections of the VP-to the lateral hypothalamus (VPâLH), ventral tegmental area (VPâVTA), lateral habenula (VPâLHb), and mediodorsal thalamus (VPâMDT)-with physiological, anatomical, genetic, and behavioral tools. We also tested for physiological differences between VP neurons receiving input from nucleus accumbens medium spiny neurons (MSNs) that express either the D1 (D1-MSNs) or the D2 (D2-MSNs) dopamine receptor. We show that each VP projection (1) when inhibited during a cocaine conditioned place preference (CPP) test affects performance differently, (2) receives a different pattern of inputs using rabies retrograde labeling, (3) shows differentially expressed genes using RNA sequencing, and (4) has projection-specific characteristics in excitability and synaptic input characteristics using whole-cell patch clamp. VPâLH and VPâVTA projections have different effects on CPP and show low overlap in circuit tracing experiments, as VPâVTA neurons receive more striatal input, while VPâLH neurons receive more olfactory input. Additionally, VPâVTA neurons are less excitable, while VPâLH neurons are more excitable than the average VP neuron, a difference driven mainly by D2-MSN-responding neurons. Thus, VPâVTA and VPâLH neurons may represent largely distinct populations of VP neurons.
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Prosencéfalo Basal , Cocaína , Vías Nerviosas , Recompensa , Animales , Ratones , Prosencéfalo Basal/fisiología , Masculino , Cocaína/farmacología , Cocaína/administración & dosificación , Femenino , Vías Nerviosas/fisiología , Ratones Endogámicos C57BL , Receptores de Dopamina D1/metabolismo , Receptores de Dopamina D1/genética , Receptores de Dopamina D2/metabolismo , Receptores de Dopamina D2/genética , Área Tegmental Ventral/fisiología , Área Tegmental Ventral/citologíaRESUMEN
Dopamine can exert effects in the mammalian heart via five different dopamine receptors. There is controversy whether dopamine receptors increase contractility in the human heart. Therefore, we have generated mice that overexpress the human D1-dopamine receptor in the heart (D1-TG) and hypothesized that dopamine increases force of contraction and beating rate compared to wild-type mice (WT). In D1-TG hearts, we ascertained the presence of D1-dopamine receptors by autoradiography using [3H]SKF 38393. The mRNA for human D1-dopamine receptors was present in D1-TG hearts and absent in WT. We detected by in-situ-hybridization mRNA for D1-dopamine receptors in atrial and ventricular D1-TG cardiomyocytes compared to WT but also in human atrial preparations. We noted that in the presence of 10 µM propranolol (to antagonize ß-adrenoceptors), dopamine alone and the D1- and D5-dopamine receptor agonist SKF 38393 (0.1-10 µM cumulatively applied) exerted concentration- and time-dependent positive inotropic effects and positive chronotropic effects in left or right atrial preparations from D1-TG. The positive inotropic effects of SKF 38393 in left atrial preparations from D1-TG led to an increased rate of relaxation and accompanied by and probably caused by an augmented phosphorylation state of the inhibitory subunit of troponin. In the presence of 0.4 µM propranolol, 1 µM dopamine could increase left ventricular force of contraction in isolated perfused hearts from D1-TG. In this model, we have demonstrated a positive inotropic and chronotropic effect of dopamine. Thus, in principle, the human D1-dopamine receptor can couple to contractility in the mammalian heart.
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Ratones Transgénicos , Contracción Miocárdica , Receptores de Dopamina D1 , Animales , Receptores de Dopamina D1/metabolismo , Receptores de Dopamina D1/genética , Humanos , Contracción Miocárdica/efectos de los fármacos , Masculino , Dopamina/metabolismo , Ratones , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/efectos de los fármacos , Agonistas de Dopamina/farmacología , Miocardio/metabolismo , 2,3,4,5-Tetrahidro-7,8-dihidroxi-1-fenil-1H-3-benzazepina/farmacología , ARN Mensajero/metabolismo , ARN Mensajero/genética , Atrios Cardíacos/metabolismo , Atrios Cardíacos/efectos de los fármacos , Corazón/efectos de los fármacos , Corazón/fisiología , Ratones Endogámicos C57BL , Frecuencia Cardíaca/efectos de los fármacosRESUMEN
Exercise has been recommended as a nonpharmaceutical therapy to treat insulin resistance (IR). Previous studies showed that dopamine D1-like receptor agonists, such as fenoldopam, could improve peripheral insulin sensitivity, while antipsychotics, which are dopamine receptor antagonists, increased susceptibility to Type 2 diabetes mellitus (T2DM). Meanwhile, exercise has been proved to stimulate dopamine receptors. However, whether the dopamine D1 receptor (D1R) is involved in exercise-mediated amelioration of IR remains unclear. We found that the D1-like receptor antagonist, SCH23390, reduced the effect of exercise on lowering blood glucose and insulin in insulin-resistant mice and inhibited the contraction-induced glucose uptake in C2C12 myotubes. Similarly, the opposite was true for the D1-like receptor agonist, fenoldopam. Furthermore, the expression of D1R was decreased in skeletal muscles from streptozotocin (STZ)- and high-fat intake-induced T2DM mice, accompanied by increased D1R phosphorylation, which was reversed by exercise. A screening study showed that G protein-coupled receptor kinase 4 (GRK4) may be the candidate kinase for the regulation of D1R function, because, in addition to the increased GRK4 expression in skeletal muscles of T2DM mice, GRK4 transgenic T2DM mice exhibited lower insulin sensitivity, accompanied by higher D1R phosphorylation than control mice, whereas the AAV9-shGRK4 mice were much more sensitive to insulin than AAV9-null mice. Mechanistically, the up-regulation of GRK4 expression caused by increased reactive oxygen species (ROS) in IR was ascribed to the enhanced expression of c-Myc, a transcriptional factor of GRK4. Taken together, the present study shows that exercise, via regulation of ROS/c-Myc/GRK4 pathway, ameliorates D1R dysfunction and improves insulin sensitivity.
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Diabetes Mellitus Tipo 2 , Resistencia a la Insulina , Animales , Ratones , Fenoldopam , Insulina , Músculo Esquelético , Especies Reactivas de Oxígeno , Receptores de Dopamina D1/genéticaRESUMEN
Attention-deficit hyperactivity disorder (ADHD) is a highly heritable neurodevelopmental disorder that affects approximately 5.3% of children and approximately 2.5% of adults. There is an intimate relationship between ADHD and sleep disturbance. Specifically, individuals carry a mutation in the core circadian gene CRY1 (c. 1657 + 3A > C), which results in the deletion of exon 11 expression in the CRY1 protein (CRY1Δ11), causing them to exhibit typical ADHD symptoms. However, the underlying mechanism is still elusive. In this study, we demonstrate that Cry1Δ11 (c. 1717 + 3A > C) mice showed ADHD-like symptoms, including hyperactivity, impulsivity, and deficits in learning and memory. A hyperactive cAMP signaling pathway was found in the nucleus accumbens (NAc) of Cry1Δ11 mice. We further demonstrated that upregulated c-Fos was mainly localized in dopamine D1 receptor-expressing medium spiny neurons (DRD1-MSNs) in the NAc. Neuronal excitability of DRD1-MSNs in the NAc of Cry1Δ11 mice was significantly higher than that of WT controls. Mechanistically, the CRY1Δ11 protein, in contrast to the WT CRY1 protein, failed to interact with the Gαs protein and inhibit DRD1 signaling. Finally, the DRD1 antagonist SCH23390 normalized most ADHD-like symptoms in Cry1Δ11 mice. Thus, our results reveal hyperactive DRD1 signaling as an underlying mechanism and therapeutic target for ADHD induced by the highly prevalent CRY1Δ11 mutation.