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We aimed to investigate the electrocardiogram (ECG) features in persons with chronic disorders of consciousness (DOC, ≥ 29 days since injury, DSI) resulted from the most severe brain damages. The ECG data from 30 patients with chronic DOC and 18 healthy controls (HCs) were recorded during resting wakefulness state for about five minutes. The patients were classified into vegetative state (VS) and minimally conscious state (MCS). Eight ECG metrics were extracted for comparisons between the subject subgroups, and regression analysis of the metrics were conducted on the DSI (29-593 days). The DOC patients exhibit a significantly higher heart rate (HR, p = 0.009) and lower values for SDNN (p = 0.001), CVRR (p = 0.009), and T-wave amplitude (p < 0.001) compared to the HCs. However, there're no significant differences in QRS, QT, QTc, or ST amplitude between the two groups (p > 0.05). Three ECG metrics of the DOC patients-HR, SDNN, and CVRR-are significantly correlated with the DSI. The ECG abnormalities persist in chronic DOC patients. The abnormalities are mainly manifested in the rhythm features HR, SDNN and CVRR, but not the waveform features such as QRS width, QT, QTc, ST and T-wave amplitudes.
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The blood-brain barrier (BBB) protects the central nervous system from infections or harmful substances1; its impairment can lead to or exacerbate various diseases of the central nervous system2-4. However, the mechanisms of BBB disruption during infection and inflammatory conditions5,6 remain poorly defined. Here we find that activation of the pore-forming protein GSDMD by the cytosolic lipopolysaccharide (LPS) sensor caspase-11 (refs. 7-9), but not by TLR4-induced cytokines, mediates BBB breakdown in response to circulating LPS or during LPS-induced sepsis. Mice deficient in the LBP-CD14 LPS transfer and internalization pathway10-12 resist BBB disruption. Single-cell RNA-sequencing analysis reveals that brain endothelial cells (bECs), which express high levels of GSDMD, have a prominent response to circulating LPS. LPS acting on bECs primes Casp11 and Cd14 expression and induces GSDMD-mediated plasma membrane permeabilization and pyroptosis in vitro and in mice. Electron microscopy shows that this features ultrastructural changes in the disrupted BBB, including pyroptotic endothelia, abnormal appearance of tight junctions and vasculature detachment from the basement membrane. Comprehensive mouse genetic analyses, combined with a bEC-targeting adeno-associated virus system, establish that GSDMD activation in bECs underlies BBB disruption by LPS. Delivery of active GSDMD into bECs bypasses LPS stimulation and opens the BBB. In CASP4-humanized mice, Gram-negative Klebsiella pneumoniae infection disrupts the BBB; this is blocked by expression of a GSDMD-neutralizing nanobody in bECs. Our findings outline a mechanism for inflammatory BBB breakdown, and suggest potential therapies for diseases of the central nervous system associated with BBB impairment.
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Barrera Hematoencefálica , Encéfalo , Células Endoteliales , Gasderminas , Inflamación , Animales , Femenino , Humanos , Masculino , Ratones , Membrana Basal/metabolismo , Membrana Basal/ultraestructura , Barrera Hematoencefálica/metabolismo , Barrera Hematoencefálica/patología , Barrera Hematoencefálica/ultraestructura , Barrera Hematoencefálica/virología , Encéfalo/metabolismo , Encéfalo/patología , Encéfalo/ultraestructura , Caspasas Iniciadoras/metabolismo , Dependovirus , Células Endoteliales/metabolismo , Células Endoteliales/ultraestructura , Gasderminas/antagonistas & inhibidores , Gasderminas/metabolismo , Inflamación/patología , Inflamación/metabolismo , Klebsiella pneumoniae/fisiología , Receptores de Lipopolisacáridos/metabolismo , Lipopolisacáridos/sangre , Lipopolisacáridos/farmacología , Ratones Endogámicos C57BL , Piroptosis , Sepsis/metabolismo , Sepsis/patología , Sepsis/microbiología , Análisis de la Célula Individual , Uniones Estrechas/metabolismo , Uniones Estrechas/ultraestructuraRESUMEN
The pituitary represents an essential hub in the hypothalamus-pituitary-adrenal (HPA) axis. Pituitary hormone-producing cells (HPCs) release several hormones to regulate fundamental bodily functions under normal and stressful conditions. It is well established that the pituitary endocrine gland modulates the immune system by releasing adrenocorticotropic hormone (ACTH) in response to neuronal activation in the hypothalamus. However, it remains unclear how systemic inflammation regulates the transcriptomic profiles of pituitary HPCs. Here, we performed single-cell RNA-sequencing (scRNA-seq) of the mouse pituitary and revealed that upon inflammation, all major pituitary HPCs respond robustly in a cell type-specific manner, with corticotropes displaying the strongest reaction. Systemic inflammation also led to the production and release of noncanonical bioactive molecules, including Nptx2 by corticotropes, to modulate immune homeostasis. Meanwhile, HPCs up-regulated the gene expression of chemokines that facilitated the communication between the HPCs and immune cells. Together, our study reveals extensive interactions between the pituitary and immune system, suggesting multifaceted roles of the pituitary in mediating the effects of inflammation on many aspects of body physiology.
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Hormona Liberadora de Corticotropina , Hipófisis , Ratones , Animales , Hormona Liberadora de Corticotropina/genética , Hipófisis/metabolismo , Hormona Adrenocorticotrópica/genética , Hormona Adrenocorticotrópica/metabolismo , Hormona Adrenocorticotrópica/farmacología , Inflamación/genética , Perfilación de la Expresión GénicaRESUMEN
Most animals require sleep, and sleep loss induces serious pathophysiological consequences, including death. Previous experimental approaches for investigating sleep impacts in mice have been unable to persistently deprive animals of both rapid eye movement sleep (REMS) and non-rapid eye movement sleep (NREMS). Here, we report a "curling prevention by water" paradigm wherein mice remain awake 96% of the time. After 4 days of exposure, mice exhibit severe inflammation, and approximately 80% die. Sleep deprivation increases levels of prostaglandin D2 (PGD2) in the brain, and we found that elevated PGD2 efflux across the blood-brain-barrier-mediated by ATP-binding cassette subfamily C4 transporter-induces both accumulation of circulating neutrophils and a cytokine-storm-like syndrome. Experimental disruption of the PGD2/DP1 axis dramatically reduced sleep-deprivation-induced inflammation. Thus, our study reveals that sleep-related changes in PGD2 in the central nervous system drive profound pathological consequences in the peripheral immune system.
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Privación de Sueño , Animales , Ratones , Citocinas/metabolismo , Inflamación , Prostaglandina D2 , Sueño/fisiología , Privación de Sueño/genética , Privación de Sueño/metabolismo , Síndrome , Humanos , Ratas , Línea Celular , Tormentas Ciclónicas , Neutrófilos/metabolismoRESUMEN
Anthocyanin is the main component of pigment in red-fleshed kiwifruit. 'Jinhongguan' is a new cultivar of Actinidia arguta with red peel and flesh after harvest. However, the specific types of anthocyanin in the 'Jinhongguan' fruit and its biosynthesis pathways remain largely unknown. Here, the total anthocyanin content in the fruit color conversion process was determined. The results showed that total anthocyanin content increased with the deepening color of the peel and flesh. To identify the genes related to anthocyanin biosynthesis and the types of anthocyanins in the 'Jinhongguan' fruit, a combined analysis of transcriptome and anthocyanin-targeted metabolome was carried out. A total of 5751 common differentially expressed genes (DEGs) at different stages of peel and flesh were identified, of which 2767 were common up-DEGs and 2976 were common down-DEGs. KEGG and GO enrichment analyses showed that the common up-DEGs were significantly enriched in anthocyanin synthesis-related pathways, suggesting some up-DEGs are involved in anthocyanin biosynthesis. In total, 29 metabolites were detected in the flesh by anthocyanin-targeted metabolome. Among these, nine were differential accumulation metabolites (DAMs) in comparison to red flesh vs green flesh. Six DAMs were up-regulated, with five of them were cyanidins. The content of cyanidin-3-O-galactoside was much higher than that of other DAMs, making it the main pigment in 'Jinhongguan'. Moreover, a total of 36 anthocyanin synthesis-related structural genes, 27 MYB transcription factors (TFs), 37 bHLH TFs and 9 WDR TFs were screened from the common DEGs. Correlation analysis of transcriptome and metabolome revealed that 9 structural genes, 6 MYB TFs, 6 bHLH TFs and 1 WDR TF were significantly associated with cyanidin-3-O-galactoside. Further, qRT-PCR analysis demonstrated that structural genes (AaPAL3, Aa4CL3, AaCHS2/3/8/9/11, AaDFR1/2, AaANR1, UFGT3a and UFGT6b) and TFs (MYB108, bHLH30, bHLH94-1 and WD43) play important roles in cyanidin biosynthesis. Overall, this study identified cyanidin-3-O-galactoside as the main anthocyanin type and revealed key candidate genes of red coloration of post-harvest fruit in Actinidia arguta. These findings provided new insights into the color formation mechanism of post-harvest fruit and offered a theoretical basis for color regulation in kiwifruit.
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Reward devaluation adaptively controls reward intake. It remains unclear how cortical circuits causally encode reward devaluation in healthy and depressed states. Here, we show that the neural pathway from the anterior cingulate cortex (ACC) to the basolateral amygdala (BLA) employs a dynamic inhibition code to control reward devaluation and depression. Fiber photometry and imaging of ACC pyramidal neurons reveal reward-induced inhibition, which weakens during satiation and becomes further attenuated in depression mouse models. Ablating or inhibiting these neurons desensitizes reward devaluation, causes reward intake increase and ultimate obesity, and ameliorates depression, whereas activating the cells sensitizes reward devaluation, suppresses reward consumption, and produces depression-like behaviors. Among various ACC neuron subpopulations, the BLA-projecting subset bidirectionally regulates reward devaluation and depression-like behaviors. Our study thus uncovers a corticoamygdalar circuit that encodes reward devaluation via blunted inhibition and suggests that enhancing inhibition within this circuit may offer a therapeutic approach for treating depression.
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Complejo Nuclear Basolateral , Condicionamiento Operante , Animales , Ratones , Condicionamiento Operante/fisiología , Depresión , Recompensa , Complejo Nuclear Basolateral/fisiología , Saciedad/fisiologíaRESUMEN
The expression of defensive responses to alerting sensory cues requires both general arousal and a specific arousal state associated with defensive emotions. However, it remains unclear whether these two forms of arousal can be regulated by common brain regions. We discovered that the medial sector of the auditory thalamus (ATm) in mice is a thalamic hub controlling both general and defensive arousal. The spontaneous activity of VGluT2-expressing ATm (ATmVGluT2+) neurons was correlated with and causally contributed to wakefulness. In sleeping mice, sustained ATmVGluT2+ population responses were predictive of sensory-induced arousal, the likelihood of which was markedly decreased by inhibiting ATmVGluT2+ neurons or multiple downstream pathways. In awake mice, ATmVGluT2+ activation led to heightened arousal accompanied by excessive anxiety and avoidance behavior. Notably, blocking their neurotransmission abolished alerting stimuli-induced defensive behaviors. These findings may shed light on the comorbidity of sleep disturbances and abnormal sensory sensitivity in specific brain disorders.
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Nivel de Alerta , Tálamo , Ratones , Animales , Nivel de Alerta/fisiología , Tálamo/fisiología , Vigilia/fisiología , Neuronas/fisiología , Transmisión SinápticaRESUMEN
Transition metal carbides show remarkable catalysis for MgH2, and the addition of carbon materials can attach excellent cycling stability. In this paper, Mg-doped with transition metal carbides (TiC) and graphene (G) composite (denoted as Mg-TiC-G) is designed to assess the influence of TiC and graphene on the hydrogen storage performance of MgH2. The as-prepared Mg-TiC-G samples showed favorable dehydrogenation kinetics compared to the pristine Mg system. After adding TiC and graphene, the dehydrogenation activation energy of MgH2decreases from 128.4 to 111.2 kJ mol-1. The peak desorption temperature of MgH2doped with TiC and graphene is 326.5 °C, which is 26.3 °C lower than the pure Mg. The improved dehydrogenation performance of Mg-TiC-G composites is attributed to synergistic effects between catalysis and confinement.
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The purinergic signaling molecule adenosine (Ado) modulates many physiological and pathological functions in the brain. However, the exact source of extracellular Ado remains controversial. Here, utilizing a newly optimized genetically encoded GPCR-Activation-Based Ado fluorescent sensor (GRABAdo), we discovered that the neuronal activity-induced extracellular Ado elevation is due to direct Ado release from somatodendritic compartments of neurons, rather than from the axonal terminals, in the hippocampus. Pharmacological and genetic manipulations reveal that the Ado release depends on equilibrative nucleoside transporters but not the conventional vesicular release mechanisms. Compared with the fast-vesicular glutamate release, the Ado release is slow (~40 s) and requires calcium influx through L-type calcium channels. Thus, this study reveals an activity-dependent second-to-minute local Ado release from the somatodendritic compartments of neurons, potentially serving modulatory functions as a retrograde signal.
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Adenosina , Neuronas , Adenosina/farmacología , Proteínas de Transporte de Nucleósidos/genética , Transducción de Señal/fisiología , Factores de Intercambio de Guanina Nucleótido/metabolismoRESUMEN
Oxytocin (OT), a peptide hormone and neuromodulator, is involved in diverse physiological and pathophysiological processes in the central nervous system and the periphery. However, the regulation and functional sequences of spatial OT release in the brain remain poorly understood. We describe a genetically encoded G-protein-coupled receptor activation-based (GRAB) OT sensor called GRABOT1.0. In contrast to previous methods, GRABOT1.0 enables imaging of OT release ex vivo and in vivo with suitable sensitivity, specificity and spatiotemporal resolution. Using this sensor, we visualize stimulation-induced OT release from specific neuronal compartments in mouse brain slices and discover that N-type calcium channels predominantly mediate axonal OT release, whereas L-type calcium channels mediate somatodendritic OT release. We identify differences in the fusion machinery of OT release for axon terminals versus somata and dendrites. Finally, we measure OT dynamics in various brain regions in mice during male courtship behavior. Thus, GRABOT1.0 provides insights into the role of compartmental OT release in physiological and behavioral functions.
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Neuronas , Oxitocina , Masculino , Ratones , Animales , Oxitocina/genética , Encéfalo , Transducción de Señal , Sistema Nervioso CentralRESUMEN
Neural activities can be modulated by leveraging light-responsive nanomaterials as interfaces for exerting photothermal, photoelectrochemical or photocapacitive effects on neurons or neural tissues. Here we show that bioresorbable thin-film monocrystalline silicon pn diodes can be used to optoelectronically excite or inhibit neural activities by establishing polarity-dependent positive or negative photovoltages at the semiconductor/solution interface. Under laser illumination, the silicon-diode optoelectronic interfaces allowed for the deterministic depolarization or hyperpolarization of cultured neurons as well as the upregulated or downregulated intracellular calcium dynamics. The optoelectronic interfaces can also be mounted on nerve tissue to activate or silence neural activities in peripheral and central nervous tissues, as we show in mice with exposed sciatic nerves and somatosensory cortices. Bioresorbable silicon-based optoelectronic thin films that selectively excite or inhibit neural tissue may find advantageous biomedical applicability.
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Nanoestructuras , Silicio , Ratones , Animales , Silicio/química , Implantes Absorbibles , Luz , Nanoestructuras/química , Nervio CiáticoRESUMEN
Kiwifruit (Actinidia chinensis Planch.) is a functionally dioecious plant, which displays diverse morphology in male and female flowers. MADS-box is an ancient and huge gene family that plays a key role in plant floral organ differentiation. In this study, we have identified 89 MADS-box genes from A. chinensis Red 5 genome. These genes are distributed on 26 chromosomes and are classified into type I (21 genes) and type II (68 genes). Overall, type II AcMADS-box genes have more complex structures than type I with more exons, protein domains, and motifs, indicating that type II genes may have more diverse functions. Gene duplication analysis showed that most collinearity occurred in type II AcMADS-box genes, which was consistent with a large number of type II genes. Analysis of cis-acting elements in promoters showed that AcMADS-box genes are mainly associated with light and phytohormone responsiveness. The expression profile of AcMADS-box genes in different tissues showed that most genes were highly expressed in flowers. Further, the qRT-PCR analysis of the floral organ ABCDE model-related genes in male and female flowers revealed that AcMADS4, AcMADS56, and AcMADS70 were significantly expressed in female flowers. It indicated that those genes may play an important role in the sex differentiation of kiwifruit. This work provided a comprehensive analysis of the AcMADS-box genes and may help facilitate our understanding of the sex differentiation regulatory mechanism in kiwifruit.
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Monosynaptic viral tracers are essential tools for dissecting neuronal connectomes and for targeted delivery of molecular sensors and effectors. Viral toxicity and complex multi-injection protocols are major limiting application barriers. To overcome these barriers, we developed an anterograde monosynaptic H129Amp tracer system based on HSV-1 strain H129. The H129Amp tracer system consists of two components: an H129-dTK-T2-pacFlox helper which assists H129Amp tracer's propagation and transneuronal monosynaptic transmission. The shared viral features of tracer/helper allow for simultaneous single-injection and subsequent high expression efficiency from multiple-copy of expression cassettes in H129Amp tracer. These improvements of H129Amp tracer system shorten experiment duration from 28-day to 5-day for fast-bright monosynaptic tracing. The lack of toxic viral genes in the H129Amp tracer minimizes toxicity in postsynaptic neurons, thus offering the potential for functional anterograde mapping and long-term tracer delivery of genetic payloads. The H129Amp tracer system is a powerful tracing tool for revealing neuronal connectomes.
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Conectoma , Red Nerviosa , Herpesvirus Humano 1/genética , NeuronasRESUMEN
As the resident immune cells in the central nervous system (CNS), microglia orchestrate immune responses and dynamically sculpt neural circuits in the CNS. Microglial dysfunction and mutations of microglia-specific genes have been implicated in many diseases of the CNS. Developing effective and safe vehicles for transgene delivery into microglia will facilitate the studies of microglia biology and microglia-associated disease mechanisms. Here, we report the discovery of adeno-associated virus (AAV) variants that mediate efficient in vitro and in vivo microglial transduction via directed evolution of the AAV capsid protein. These AAV-cMG and AAV-MG variants are capable of delivering various genetic payloads into microglia with high efficiency, and enable sufficient transgene expression to support fluorescent labeling, Ca2+ and neurotransmitter imaging and genome editing in microglia in vivo. Furthermore, single-cell RNA sequencing shows that the AAV-MG variants mediate in vivo transgene delivery without inducing microglia immune activation. These AAV variants should facilitate the use of various genetically encoded sensors and effectors in the study of microglia-related biology.
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Dependovirus , Microglía , Dependovirus/genética , Técnicas de Transferencia de Gen , Terapia Genética/métodos , Vectores Genéticos/genética , Transducción GenéticaRESUMEN
Shenqi pill (SQP), a famous traditional Chinese medicine (TCM) herbal formula derived from Jinguiyaolue (Synopsis of Prescriptions of the Golden Chamber), has long been used to treat kidney yang deficiency syndrome. According to the TCM treatment principle that the liver and kidney are homologies, the clinical use of SQP in the treatment of nonalcoholic steatohepatitis (NASH) has achieved a good effect. However, the active targeted genes and underlying mechanism remain unclear. In this study, we aimed to explore the treatment mechanism of SQP in NASH rats, which may further contribute to the in-depth exploration of SQP in clinical applications. Network pharmacology analysis was used to screen the target genes of SQP for NASH treatment based on public databases. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis, and protein-protein interaction (PPI) analysis were used to search for crucial target genes and mechanisms. UPLC-MS/MS was used to verify the active compounds of the SQP screened. The hepatic pathology and biochemical indicators of rats were used to judge the modeling results and the curative effect of SQP. Western blotting and qRT-PCR were used to verify the expression of crucial target genes at the protein and RNA levels, respectively. Network pharmacology analysis and bioinformatics analysis showed that PTGS2, JUN, MYC, and CDKN1A might be crucial target genes in the primary mechanism of SQP in treating NASH and improving the inflammatory response. The UPLC-MS/MS results confirmed that the hub active compound, quercetin, screened out through the TCMSP database, is indeed present in SQP. Hepatic injury and lipid metabolism indicators of NASH rats were significantly improved after SQP treatment. The results of WB and qRT-PCR showed that the expression of PTGS2, JUN, MYC, and CDKN1A was higher in NASH rats than in normal rats and decreased after SQP treatment. The expression of inflammatory cytokines (IL-1ß, IL-6, TNF-α) was reduced after SQP treatment, which confirmed that SQP could improve hepatic inflammation in rats. These results suggested that SQP could ameliorate NASH in rats, and that quercetin may be the critical active compound that exerts the therapeutic effect.
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Medicamentos Herbarios Chinos , Enfermedad del Hígado Graso no Alcohólico , Animales , Cromatografía Liquida , Ciclooxigenasa 2 , Medicamentos Herbarios Chinos/química , Medicamentos Herbarios Chinos/farmacología , Medicamentos Herbarios Chinos/uso terapéutico , Medicina Tradicional China , Farmacología en Red , Enfermedad del Hígado Graso no Alcohólico/tratamiento farmacológico , Enfermedad del Hígado Graso no Alcohólico/genética , Quercetina , Ratas , Espectrometría de Masas en TándemRESUMEN
Gq-coupled receptors regulate numerous physiological processes by activating enzymes and inducing intracellular Ca2+ signals. There is a strong need for an optogenetic tool that enables powerful experimental control over Gq signaling. Here, we present chicken opsin 5 (cOpn5) as the long sought-after, single-component optogenetic tool that mediates ultra-sensitive optical control of intracellular Gq signaling with high temporal and spatial resolution. Expressing cOpn5 in HEK 293T cells and primary mouse astrocytes enables blue light-triggered, Gq-dependent Ca2+ release from intracellular stores and protein kinase C activation. Strong Ca2+ transients were evoked by brief light pulses of merely 10 ms duration and at 3 orders lower light intensity of that for common optogenetic tools. Photostimulation of cOpn5-expressing cells at the subcellular and single-cell levels generated fast intracellular Ca2+ transition, thus demonstrating the high spatial precision of cOpn5 optogenetics. The cOpn5-mediated optogenetics could also be applied to activate neurons and control animal behavior in a circuit-dependent manner. cOpn5 optogenetics may find broad applications in studying the mechanisms and functional relevance of Gq signaling in both non-excitable cells and excitable cells in all major organ systems.
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Optogenética , Transducción de Señal , Animales , Luz , Ratones , Neuronas/fisiología , Transducción de Señal/fisiologíaRESUMEN
Drug addiction is characterized by relapse when addicts are re-exposed to drug-associated environmental cues, but the neural mechanisms underlying cue-induced relapse are unclear. In the present study we investigated the role of a specific dopaminergic (DA) pathway from ventral tegmental area (VTA) to nucleus accumbens core (NAcore) in mouse cue-induced relapse. Optical intracranial self-stimulation (oICSS) was established in DAT-Cre transgenic mice. We showed that optogenetic excitation of DA neurons in the VTA or their projection terminals in NAcore, NAshell or infralimbic prefrontal cortex (PFC-IL) was rewarding. Furthermore, activation of the VTA-NAcore pathway alone was sufficient and necessary to induce reinstatement of oICSS. In cocaine self-administration model, cocaine-associated cues activated VTA DA neurons as assessed by intracellular GCaMP signals. Cue-induced reinstatement of cocaine-seeking was triggered by optogenetic stimulation of the VTA-NAcore pathway, and inhibited by chemogenetic inhibition of this pathway. Together, these results demonstrate that cue-induced reinstatement of reward seeking is in part mediated by activation of the VTA-NAcore DA pathway.
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Cocaína , Dopamina , Animales , Cocaína/farmacología , Señales (Psicología) , Comportamiento de Búsqueda de Drogas , Ratones , Ratones Transgénicos , Núcleo Accumbens/fisiología , Ratas , Ratas Sprague-Dawley , Recurrencia , Recompensa , AutoadministraciónRESUMEN
Optogenetic methods provide efficient cell-specific modulations, and the ability of simultaneous neural activation and inhibition in the same brain region of freely moving animals is highly desirable. Here we report bidirectional neuronal activity manipulation accomplished by a wireless, dual-color optogenetic probe in synergy with the co-expression of two spectrally distinct opsins (ChrimsonR and stGtACR2) in a rodent model. The flexible probe comprises vertically assembled, thin-film microscale light-emitting diodes with a lateral dimension of 125 × 180 µm2, showing colocalized red and blue emissions and enabling chronic in vivo operations with desirable biocompatibilities. Red or blue irradiations deterministically evoke or silence neurons co-expressing the two opsins. The probe interferes with dopaminergic neurons in the ventral tegmental area of mice, increasing or decreasing dopamine levels. Such bidirectional regulations further generate rewarding and aversive behaviors and interrogate social interactions among multiple mice. These technologies create numerous opportunities and implications for brain research.
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Conducta Animal , Optogenética/instrumentación , Optogenética/métodos , Tecnología Inalámbrica , Animales , Encéfalo/diagnóstico por imagen , Encéfalo/fisiología , Dopamina , Neuronas Dopaminérgicas , Masculino , Ratones , Ratones Endogámicos C57BL , Opsinas , Área Tegmental Ventral , Tecnología Inalámbrica/instrumentaciónRESUMEN
GABAB receptors in habenula cholinergic neurons mediate strong presynaptic excitation and control aversive memory expression. K+ channel tetramerization domain (KCTD) proteins are key interacting partners of GABAB receptors; it remains unclear whether and how KCTDs contribute to GABAB excitatory signaling. Here, we show that KCTD8 and KCTD12 in these neurons facilitate the GABAB receptors expression in axonal terminals and contribute to presynaptic excitation by GABAB receptors. Genetically knocking out KCTD8/12/16 or KCTD8/12, but not other combinations of the three KCTD isoforms, substantially reduced GABAB receptors-mediated potentiation of glutamate release and presynaptic Ca2+ entry in response to axonal stimulation, whereas they had no effect on GABAB-mediated inhibition in the somata of cholinergic neurons within the habenulo-interpeduncular pathway in mice of either sex. The physiological phenotypes were associated with a significant decrease in the GABAB expression within the axonal terminals but not the somata. Overexpressing either KCTD8 or KCTD12 in the KCTD8/12/16 triple knock-out mice reversed the changes in axonal GABAB expression and presynaptic excitation. In mice lacking the KCTDs, aversion-predicting cues produced stronger neuronal activation in the interpeduncular nucleus, and the infusion of GABAB agonist in this nucleus produced a weaker effect on fear extinction. Collectively, our results reveal isoform-specific roles of KCTD proteins in enriching the axonal expression of GABAB receptors, facilitating their presynaptic signaling, and modulating aversion-related memory processes.SIGNIFICANCE STATEMENT GABAB receptors represent the principal inhibitory neurotransmitter receptor, but they mediate strong presynaptic excitation in the habenulo-interpeduncular pathway and modulate aversion memory expression. KCTD proteins are integral constituents of GABAB receptors. By analyzing the physiological, neuroanatomical, and behavioral phenotypes of multiple KCTD knock-out mouse lines, we show that KCTD8 and KCTD12 facilitate the axonal expression and hence presynaptic excitation of GABAB receptors in habenula cholinergic neurons and control cued-aversion memory formation and expression in the habenulo-interpeduncular pathway. These results expand the physiological and behavioral functions of KCTDs in modulating the brain neural circuits.
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Axones , Neuronas Colinérgicas , Habénula , Péptidos y Proteínas de Señalización Intracelular , Receptores de GABA-B , Receptores de GABA , Animales , Axones/metabolismo , Neuronas Colinérgicas/metabolismo , Extinción Psicológica , Miedo/fisiología , Habénula/metabolismo , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Ratones , Ratones Noqueados , Receptores de GABA/metabolismo , Receptores de GABA-B/genética , Receptores de GABA-B/metabolismo , Ácido gamma-Aminobutírico/metabolismoRESUMEN
Licking behavior is important for water intake. The deep mesencephalic nucleus (DpMe) has been implicated in instinctive behaviors. However, whether the DpMe is involved in licking behavior and the precise neural circuit behind this behavior remains unknown. Here, we found that the activity of the DpMe decreased during water intake. Inhibition of vesicular glutamate transporter 2-positive (VGLUT2+) neurons in the DpMe resulted in increased water intake. Somatostatin-expressing (SST+), but not protein kinase C-δ-expressing (PKC-δ+), GABAergic neurons in the central amygdala (CeA) preferentially innervated DpMe VGLUT2+ neurons. The SST+ neurons in the CeA projecting to the DpMe were activated at the onset of licking behavior. Activation of these CeA SST+ GABAergic neurons, but not PKC-δ+ GABAergic neurons, projecting to the DpMe was sufficient to induce licking behavior and promote water intake. These findings redefine the roles of the DpMe and reveal a novel CeASST-DpMeVGLUT2 circuit that regulates licking behavior and promotes water intake.