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1.
Nat Commun ; 11(1): 3996, 2020 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-32778725

RESUMO

Psychomotor stimulants increase dopamine levels in the striatum and promote locomotion; however, their effects on striatal pathway function in vivo remain unclear. One model that has been proposed to account for these motor effects suggests that stimulants drive hyperactivity via activation and inhibition of direct and indirect pathway striatal neurons, respectively. Although this hypothesis is consistent with the cellular actions of dopamine receptors and received support from optogenetic and chemogenetic studies, it has been rarely tested with in vivo recordings. Here, we test this model and observe that cocaine increases the activity of both pathways in the striatum of awake mice. These changes are linked to a dopamine-dependent cocaine-induced strengthening of upstream orbitofrontal cortex (OFC) inputs to the dorsomedial striatum (DMS) in vivo. Finally, depressing OFC-DMS pathway with a high frequency stimulation protocol in awake mice over-powers the cocaine-induced potentiation of OFC-DMS pathway and attenuates the expression of locomotor sensitization, directly linking OFC-DMS potentiation to cocaine-induced hyperactivity.


Assuntos
Estimulantes do Sistema Nervoso Central/farmacologia , Cocaína/farmacologia , Corpo Estriado/efeitos dos fármacos , Corpo Estriado/metabolismo , Hipercinese/metabolismo , Córtex Pré-Frontal/efeitos dos fármacos , Córtex Pré-Frontal/metabolismo , Animais , Comportamento Animal , Modelos Animais de Doenças , Dopamina , Feminino , Hipercinese/induzido quimicamente , Locomoção/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Optogenética
2.
Artigo em Russo | MEDLINE | ID: mdl-32790988

RESUMO

A systematic review of association studies on the role of single nucleotide variants (SNVs) of the dopaminergic system genes on the effectiveness of clozapine in schizophrenia has been perfromed. A search of literature was conducted in PubMed, MedLine, Web of Science Core Collection (Clarivate Analytics), Web of Science, Russian Science Citation Index, Scopus, Scientific Research, Google Scholar, Oxford Press, e-Library from 1995-2019. Association studies of 53 SNPs of genes encoding dopamine receptor isoforms (DRD1), dopamine transporter (SCL6A3) and catechol-O- methyltransferase (COMT), and the nature of their association with the therapeutic response to clozapine were analyzed. The results of SNPs studies of DRD1 and COMT genes are the most controversial. This can be explained by the heterogeneity of the samples and the lack of standardization of methods for evaluating the effectiveness of treatment in the context of association studies. The clear population specificity of the association of some SNPs of DRD1, DRD2 and DRD3 genes with the response to clozapine therapy has been shown. Most of the identified associations are haplotype specific. The obtained regularities of the effect of SNPs of dopaminergic system genes on the effectiveness of clozapine therapy should be considered in an individual approach to treatment of schizophrenia.


Assuntos
Clozapina , Esquizofrenia , Catecol O-Metiltransferase/genética , Dopamina , Genótipo , Humanos , Farmacogenética , Polimorfismo de Nucleotídeo Único , Federação Russa
3.
PLoS One ; 15(7): e0235407, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32649670

RESUMO

Fast scan cyclic voltammetry (FSCV) allows for real -time analysis of phasic neurotransmitter levels. Tryptophan (TRP) is an aromatic amino acid responsible for facilitating electron transfer kinetics in oxidoreductase enzymes. Previous work with TRP-modified electrodes showed increased sensitivity for cyclic voltammetry detection of dopamine (DA) when used with slower scan rates (0.05 V/s). Here, we outline an in vitro proof of concept for TRP-modified electrodes in FSCV detection of DA, and decreased sensitivity for ascorbic acid (AA). TRP-modified electrodes had a limit of detection (LOD) for DA of 2.480 ± 0.343 nM compared to 8.348 ± 0.405 nM for an uncoated electrode. Selectivity for DA/ascorbic acid (AA) was 1.107 ± 0.3643 for uncoated and 15.57 ± 4.184 for TRP-modified electrodes. Additionally, these TRP-modified electrodes demonstrated reproducibility when exposed to extended cycling. TRP-modified electrodes will provide an effective modification to increase sensitivity for DA.


Assuntos
Técnicas Biossensoriais , Dopamina/isolamento & purificação , Técnicas Eletroquímicas , Ácido Ascórbico/química , Carbono/química , Dopamina/química , Eletrodos , Cinética , Triptofano/química , Ácido Úrico/química
4.
Proc Biol Sci ; 287(1930): 20201069, 2020 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-32605517

RESUMO

Expression of adaptive reaction norms of life-history traits to spatio-temporal variation in food availability is crucial for individual fitness. Yet little is known about the neural signalling mechanisms underlying these reaction norms. Previous studies suggest a role for the dopamine system in regulating behavioural and morphological responses to food across a wide range of taxa. We tested whether this neural signalling system also regulates life-history reaction norms by exposing the zooplankton Daphnia magna to both dopamine and the dopamine reuptake inhibitor bupropion, an antidepressant that enters aquatic environments via various pathways. We recorded a range of life-history traits across two food levels. Both treatments induced changes to the life-history reaction norm slopes. These were due to the effects of the treatments being more pronounced at restricted food ration, where controls had lower somatic growth rates, higher age and larger size at maturation. This translated into a higher population growth rate (r) of dopamine and bupropion treatments when food was restricted. Our findings show that the dopamine system is an important regulatory mechanism underlying life-history trait responses to food abundance and that bupropion can strongly influence the life history of aquatic species such as D. magna. We discuss why D. magna do not evolve towards higher endogenous dopamine levels despite the apparent fitness benefits.


Assuntos
Daphnia/fisiologia , Dopamina/metabolismo , Animais , Evolução Biológica , Alimentos , Traços de História de Vida , Reprodução , Zooplâncton
5.
Life Sci ; 257: 118019, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32629002

RESUMO

Parkinson's disease (PD) is a disease of the human nervous system with an onset, in the sixth and seventh decades of the human life. Chiefly perceived as progressive degeneration of dopaminergic (DA) neurons in the substantia nigra pars compacta (SNpc) with the ensued loss of dopamine in the striatum and the presence of Lewy bodies, consisting of α-synuclein agglomeration. In which the neuronal bridge between substantia nigra and striatum plays an advent role in the motor system. Dilapidation of these neurons results in dopamine depletion which in-turn makes hay to PD. Eventually, the etiology and pathogenesis of PD were still on a hike of dilemma. Traditional Chinese medicine (TCM), including Chinese herbal remedies, acupuncture, and manipulative therapies, is commonly used as an adjunctive therapy in different diseases, particularly neurological diseases, in Asian countries. Additionally, TCM might improve the prognoses and the quality of life of patients with PD because it induces less adverse drug reactions. The present review describes research on the various neuroprotective components and herbal extracts from herbal medicines in the context of addressing the effects of PD.


Assuntos
Medicina Tradicional Chinesa/métodos , Doença de Parkinson/tratamento farmacológico , Doença de Parkinson/terapia , Animais , Encéfalo/metabolismo , Corpo Estriado/metabolismo , Modelos Animais de Doenças , Dopamina , Neurônios Dopaminérgicos/efeitos dos fármacos , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Fármacos Neuroprotetores/farmacologia , Parte Compacta da Substância Negra/metabolismo , Substância Negra/efeitos dos fármacos , Tirosina 3-Mono-Oxigenase/metabolismo , alfa-Sinucleína/metabolismo
6.
Life Sci ; 257: 118070, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32668327

RESUMO

AIMS: Several studies suggested that ATP-sensitive potassium channels (KATP) are potential therapeutic targets for protection against various neurodegenerative disorders, yet, there is an ongoing controversy regarding their role in Parkinson's disease (PD). Thus, the aim of the current study is to investigate the protective effect of KATP blockade and activation in the mice rotenone model of PD. MAIN METHODS: PD has been induced by 9 subcutaneous injections of rotenone (1.5 mg/kg; 3 times/week) in adult male Swiss albino mice. For 3 consecutive weeks, parkinsonian mice were either untreated or treated with L-dopa (25 mg/kg), the KATP channel blocker glibenclamide (3 mg/kg) or the KATP channel opener nicorandil (6 mg/kg). KEY FINDINGS: Glibenclamide significantly improved motor performance in the wire hanging and stair tests and halted the decline in striatal dopamine content as well as dopaminergic neurons' density. In addition, it reduced the rotenone-induced apoptosis as portrayed in the immunohistopathological examination via increasing Bcl-2 and decreasing caspases-3, -8, -9 contents. Furthermore, through its anti-inflammatory potential, glibenclamide reduced tumor necrosis factor-alpha level. On the other hand, nicorandil failed to mitigate the rotenone-induced neurodegenerative consequences. SIGNIFICANCE: KATP channel blockade by glibenclamide has neuroprotective effect against rotenone-induced neurotoxicity, that was mediated by its anti-inflammatory effect along with hindering apoptosis through extrinsic and intrinsic pathways.


Assuntos
Glibureto/farmacologia , Canais KATP/antagonistas & inibidores , Fármacos Neuroprotetores/farmacologia , Transtornos Parkinsonianos/tratamento farmacológico , Bloqueadores dos Canais de Potássio/farmacologia , Animais , Apoptose/efeitos dos fármacos , Dopamina/metabolismo , Neurônios Dopaminérgicos/metabolismo , Canais KATP/metabolismo , Levodopa/farmacologia , Masculino , Camundongos , Nicorandil/farmacologia , Transtornos Parkinsonianos/fisiopatologia , Rotenona/toxicidade
7.
PLoS Comput Biol ; 16(7): e1008078, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32701987

RESUMO

Animals remember temporal links between their actions and subsequent rewards. We previously discovered a synaptic mechanism underlying such reward learning in D1 receptor (D1R)-expressing spiny projection neurons (D1 SPN) of the striatum. Dopamine (DA) bursts promote dendritic spine enlargement in a time window of only a few seconds after paired pre- and post-synaptic spiking (pre-post pairing), which is termed as reinforcement plasticity (RP). The previous study has also identified underlying signaling pathways; however, it still remains unclear how the signaling dynamics results in RP. In the present study, we first developed a computational model of signaling dynamics of D1 SPNs. The D1 RP model successfully reproduced experimentally observed protein kinase A (PKA) activity, including its critical time window. In this model, adenylate cyclase type 1 (AC1) in the spines/thin dendrites played a pivotal role as a coincidence detector against pre-post pairing and DA burst. In particular, pre-post pairing (Ca2+ signal) stimulated AC1 with a delay, and the Ca2+-stimulated AC1 was activated by the DA burst for the asymmetric time window. Moreover, the smallness of the spines/thin dendrites is crucial to the short time window for the PKA activity. We then developed a RP model for D2 SPNs, which also predicted the critical time window for RP that depended on the timing of pre-post pairing and phasic DA dip. AC1 worked for the coincidence detector in the D2 RP model as well. We further simulated the signaling pathway leading to Ca2+/calmodulin-dependent protein kinase II (CaMKII) activation and clarified the role of the downstream molecules of AC1 as the integrators that turn transient input signals into persistent spine enlargement. Finally, we discuss how such timing windows guide animals' reward learning.


Assuntos
Sinalização do Cálcio , Corpo Estriado/fisiologia , Proteínas Quinases Dependentes de AMP Cíclico/fisiologia , Dopamina/fisiologia , Aprendizagem , Plasticidade Neuronal , Animais , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/fisiologia , Simulação por Computador , Dendritos/fisiologia , Espinhas Dendríticas/fisiologia , Cinética , Camundongos , Neurônios/fisiologia , Receptores de Dopamina D2 , Recompensa
8.
Proc Natl Acad Sci U S A ; 117(29): 17296-17307, 2020 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-32631998

RESUMO

Mutations in leucine-rich repeat kinase 2 (LRRK2) are the most common cause of late-onset, autosomal-dominant familial Parkinson's disease (PD). LRRK2 functions as both a kinase and GTPase, and PD-linked mutations are known to influence both enzymatic activities. While PD-linked LRRK2 mutations can commonly induce neuronal damage in culture models, the mechanisms underlying these pathogenic effects remain uncertain. Rodent models containing familial LRRK2 mutations often lack robust PD-like neurodegenerative phenotypes. Here, we develop a robust preclinical model of PD in adult rats induced by the brain delivery of recombinant adenoviral vectors with neuronal-specific expression of human LRRK2 harboring the most common G2019S mutation. In this model, G2019S LRRK2 induces the robust degeneration of substantia nigra dopaminergic neurons, a pathological hallmark of PD. Introduction of a stable kinase-inactive mutation or administration of the selective kinase inhibitor, PF-360, attenuates neurodegeneration induced by G2019S LRRK2. Neuroprotection provided by pharmacological kinase inhibition is mediated by an unusual mechanism involving the robust destabilization of human LRRK2 protein in the brain relative to endogenous LRRK2. Our study further demonstrates that G2019S LRRK2-induced dopaminergic neurodegeneration critically requires normal GTPase activity, as hypothesis-testing mutations that increase GTP hydrolysis or impair GTP-binding activity provide neuroprotection although via distinct mechanisms. Taken together, our data demonstrate that G2019S LRRK2 induces neurodegeneration in vivo via a mechanism that is dependent on kinase and GTPase activity. Our study provides a robust rodent preclinical model of LRRK2-linked PD and nominates kinase inhibition and modulation of GTPase activity as promising disease-modifying therapeutic targets.


Assuntos
Neurônios Dopaminérgicos/metabolismo , GTP Fosfo-Hidrolases/metabolismo , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina/metabolismo , Doença de Parkinson/metabolismo , Animais , Encéfalo/metabolismo , Encéfalo/patologia , Linhagem Celular , Modelos Animais de Doenças , Dopamina/metabolismo , Feminino , Humanos , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina/genética , Camundongos , Camundongos Knockout , Mutação , Doenças Neurodegenerativas/tratamento farmacológico , Doenças Neurodegenerativas/metabolismo , Doença de Parkinson/patologia , Fenótipo , Projetos Piloto , Inibidores de Proteínas Quinases/farmacologia , Ratos , Ratos Wistar , Substância Negra
9.
Nat Commun ; 11(1): 3369, 2020 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-32632153

RESUMO

Induced pluripotent stem cell (iPSC)-derived dopaminergic (DA) neurons are an expected source for cell-based therapies for Parkinson's disease (PD). The regulatory criteria for the clinical application of these therapies, however, have not been established. Here we show the results of our pre-clinical study, in which we evaluate the safety and efficacy of dopaminergic progenitors (DAPs) derived from a clinical-grade human iPSC line. We confirm the characteristics of DAPs by in vitro analyses. We also verify that the DAP population include no residual undifferentiated iPSCs or early neural stem cells and have no genetic aberration in cancer-related genes. Furthermore, in vivo studies using immunodeficient mice reveal no tumorigenicity or toxicity of the cells. When the DAPs are transplanted into the striatum of 6-OHDA-lesioned rats, the animals show behavioral improvement. Based on these results, we started a clinical trial to treat PD patients in 2018.


Assuntos
Neurônios Dopaminérgicos/citologia , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Neurais/transplante , Doença de Parkinson/terapia , Transplante de Células-Tronco/métodos , Animais , Diferenciação Celular/genética , Linhagem Celular , Modelos Animais de Doenças , Dopamina/metabolismo , Neurônios Dopaminérgicos/metabolismo , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Macaca fascicularis , Masculino , Camundongos Endogâmicos NOD , Camundongos Knockout , Camundongos SCID , Células-Tronco Neurais/citologia , Células-Tronco Neurais/metabolismo , Avaliação de Resultados em Cuidados de Saúde/métodos , Avaliação de Resultados em Cuidados de Saúde/estatística & dados numéricos , Ratos Nus , Transplante Heterólogo
10.
Nat Commun ; 11(1): 3460, 2020 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-32651365

RESUMO

The learning of stimulus-outcome associations allows for predictions about the environment. Ventral striatum and dopaminergic midbrain neurons form a larger network for generating reward prediction signals from sensory cues. Yet, the network plasticity mechanisms to generate predictive signals in these distributed circuits have not been entirely clarified. Also, direct evidence of the underlying interregional assembly formation and information transfer is still missing. Here we show that phasic dopamine is sufficient to reinforce the distinctness of stimulus representations in the ventral striatum even in the absence of reward. Upon such reinforcement, striatal stimulus encoding gives rise to interregional assemblies that drive dopaminergic neurons during stimulus-outcome learning. These assemblies dynamically encode the predicted reward value of conditioned stimuli. Together, our data reveal that ventral striatal and midbrain reward networks form a reinforcing loop to generate reward prediction coding.


Assuntos
Dopamina/metabolismo , Neurônios Dopaminérgicos/efeitos dos fármacos , Neurônios Dopaminérgicos/metabolismo , Tubérculo Olfatório/efeitos dos fármacos , Animais , Dopamina/farmacologia , Masculino , Mesencéfalo/citologia , Camundongos , Modelos Teóricos , Estriado Ventral/efeitos dos fármacos , Estriado Ventral/metabolismo
12.
Front Immunol ; 11: 1472, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32655579

RESUMO

Severe acute respiratory syndrome coronavirus 2 has spread rapidly around the globe. However, despite its high pathogenicity and transmissibility, the severity of the associated disease, COVID-19, varies widely. While the prognosis is favorable in most patients, critical illness, manifested by respiratory distress, thromboembolism, shock, and multi-organ failure, has been reported in about 5% of cases. Several studies have associated poor COVID-19 outcomes with the exhaustion of natural killer cells and cytotoxic T cells, lymphopenia, and elevated serum levels of D-dimer. In this article, we propose a common pathophysiological denominator for these negative prognostic markers, endogenous, angiotensin II toxicity. We hypothesize that, like in avian influenza, the outlook of COVID-19 is negatively correlated with the intracellular accumulation of angiotensin II promoted by the viral blockade of its degrading enzyme receptors. In this model, upregulated angiotensin II causes premature vascular senescence, leading to dysfunctional coagulation, and immunity. We further hypothesize that angiotensin II blockers and immune checkpoint inhibitors may be salutary for COVID-19 patients with critical illness by reversing both the clotting and immune defects (Graphical Abstract).


Assuntos
Angiotensina II/sangue , Betacoronavirus/metabolismo , Infecções por Coronavirus/sangue , Infecções por Coronavirus/fisiopatologia , Pneumonia Viral/sangue , Pneumonia Viral/fisiopatologia , Regulação para Cima , Fatores Etários , Antagonistas de Receptores de Angiotensina/uso terapêutico , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Encéfalo/imunologia , Encéfalo/metabolismo , Senescência Celular/efeitos dos fármacos , Infecções por Coronavirus/tratamento farmacológico , Infecções por Coronavirus/virologia , Estado Terminal , Citocinas/metabolismo , Dopamina/metabolismo , Regulação para Baixo , Humanos , Imunoterapia/métodos , Mitocôndrias/metabolismo , Pandemias , Peptidil Dipeptidase A/metabolismo , Pneumonia Viral/tratamento farmacológico , Pneumonia Viral/virologia , Prognóstico , Sistema Renina-Angiotensina/imunologia
13.
Yonsei Med J ; 61(7): 644-646, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32608210

RESUMO

A weight-holding tremor is a rare type of hand tremor that occurs only when someone holds some weight. Here we report three cases of isolated weight-holding tremors, of which one patient was diagnosed with Parkinson's disease (PD) and the others as a variant of essential tremor (ET). A 68-year-old woman presented with a left-hand tremor that appeared only when she held objects with some weight. Her tremor was reminiscent of the re-emergent tremor of PD, and dopamine transporter imaging revealed reduced uptake at the right posterior putamen. A 21-year-old man and a 71-year-old woman also presented with similar weight-holding tremors. However, these tremors were not re-emergent, and no signs of parkinsonism were observed during follow-up. Although the underlying etiologies of these tremors differed, all three tremors worsened as the held weight increased. These tremors could be isolated isometric tremors, but further research is needed to clarify the nature of this rare tremor.


Assuntos
Tremor Essencial/diagnóstico , Doença de Parkinson/complicações , Tomografia por Emissão de Pósitrons/métodos , Tremor/diagnóstico por imagem , Tremor/etiologia , Adulto , Idoso , Peso Corporal , Dopamina/metabolismo , Proteínas da Membrana Plasmática de Transporte de Dopamina/metabolismo , Tremor Essencial/fisiopatologia , Feminino , Humanos , Masculino , Tremor/classificação , Tremor/fisiopatologia
14.
Nature ; 584(7819): 125-129, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32528175

RESUMO

The D2 dopamine receptor (DRD2) is a therapeutic target for Parkinson's disease1 and antipsychotic drugs2. DRD2 is activated by the endogenous neurotransmitter dopamine and synthetic agonist drugs such as bromocriptine3, leading to stimulation of Gi and inhibition of adenylyl cyclase. Here we used cryo-electron microscopy to elucidate the structure of an agonist-bound activated DRD2-Gi complex reconstituted into a phospholipid membrane. The extracellular ligand-binding site of DRD2 is remodelled in response to agonist binding, with conformational changes in extracellular loop 2, transmembrane domain 5 (TM5), TM6 and TM7, propagating to opening of the intracellular Gi-binding site. The DRD2-Gi structure represents, to our knowledge, the first experimental model of a G-protein-coupled receptor-G-protein complex embedded in a phospholipid bilayer, which serves as a benchmark to validate the interactions seen in previous detergent-bound structures. The structure also reveals interactions that are unique to the membrane-embedded complex, including helix 8 burial in the inner leaflet, ordered lysine and arginine side chains in the membrane interfacial regions, and lipid anchoring of the G protein in the membrane. Our model of the activated DRD2 will help to inform the design of subtype-selective DRD2 ligands for multiple human central nervous system disorders.


Assuntos
Microscopia Crioeletrônica , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/química , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/ultraestrutura , Lipídeos de Membrana/metabolismo , Membranas Artificiais , Receptores de Dopamina D2/química , Receptores de Dopamina D2/ultraestrutura , Bromocriptina/química , Bromocriptina/metabolismo , Dopamina/química , Dopamina/metabolismo , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/metabolismo , Humanos , Lipídeos de Membrana/química , Modelos Moleculares , Conformação Proteica , Receptores de Dopamina D2/agonistas , Receptores de Dopamina D2/metabolismo , Transdução de Sinais
15.
Beijing Da Xue Xue Bao Yi Xue Ban ; 52(3): 438-443, 2020 Jun 18.
Artigo em Chinês | MEDLINE | ID: mdl-32541975

RESUMO

OBJECTIVE: To analyze the effect of benzopyrene on the decrease of dopaminergic neurons, and the increase and aggregation of α-synuclein, which are the pathological features of Parkinson's disease, and to explore its possible mechanisms. METHODS: Eight-month-old transgenic mice with human SNCA gene were randomly divided into a BaP-exposed group and a control group. BaP and solvent corn oil were injected intraperitoneally to BaP-exposed group and control group respectively, once a day for 60 days. The motor dysfunction of mice was tested by rotarod test. The effects of BaP on the decrease of dopaminergic neurons and increase and aggregation of α-synuclein were observed by immunohistochemistry and Western blot experiments respectively, and the expression of related mRNA was detected by quantitative real-time PCR (qRT-PCR). Twenty genes were tested in the study, mainly related to neurotransmitter transporter (2 genes), neurotransmitter receptor function (10 genes), cellular autophagy (5 genes), and α-synuclein aggregation and degradation (3 genes). RESULTS: After BaP exposure, the movement time of the mice in the rotarod test was significantly reduced (P<0.05). The substantia nigra dopami-nergic neurons in the mice were significantly reduced, which was 62% of the control group (P<0.05), and the expression of α-synuclein in the midbrain increased, which was 1.36 times that of the control group (P<0.05). After BaP exposure, mRNA expressions of 14 genes in the midbrain of the mice were significantly down-regulated (P<0.05). Alpha-synuclein degradation and cell autophagy (5 genes), neuron transporters (2 genes), and neurotransmitter receptor functions (5 genes) were involved. The expression of one gene, Synphilin-1, was significantly up-regulated (P<0.01), which was related to α-synuclein aggregation. CONCLUSION: BaP exposure not only inhibited function of neurotransmitter receptor and dopamine transporter, but also interfered cell autophagy, thereby hindering the degradation of α-synuclein, which could lead to decrease of dopaminergic neurons in substantia nigra and increase and aggregation of α-synuclein in midbrain, as the significant pathology of Parkinson's disease. Therefore, BaP exposure may increase the risk of Parkinson's disease.


Assuntos
Neurônios Dopaminérgicos , Animais , Benzo(a)pireno , Encéfalo , Dopamina , Humanos , Camundongos , alfa-Sinucleína
16.
Artigo em Russo | MEDLINE | ID: mdl-32490630

RESUMO

Restless legs syndrome (RLS) is a sensorimotor disorder characterized by complaints of a strong desire to move legs during periods of rest or inactivity, which is relieved by movement (most pronounced in the evening or at night). Multiple studies have reported drug-induced RLS caused by antipsychotics, antidepressants and antiepileptic medications. Risk factors for drug-induced RLS include older age, gastrointestinal diseases, high medication dose, simultaneous use of ≥2 drugs. The mechanism of drug-induced RLS is most often associated with the effect of medications on various receptors and neurotransmitter systems, in particular, the dopamine system. Drug-induced RLS treatment includes identification and withdrawal of a drug that caused RLS or a decrease in its dosage. Prevention of drug-induced RLS is based on compliance with the principles of rational pharmacotherapy.


Assuntos
Síndrome das Pernas Inquietas , Idoso , Dopamina , Agonistas de Dopamina , Humanos , Movimento
17.
Nature ; 582(7811): 246-252, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32499648

RESUMO

A wealth of specialized neuroendocrine command systems intercalated within the hypothalamus control the most fundamental physiological needs in vertebrates1,2. Nevertheless, we lack a developmental blueprint that integrates the molecular determinants of neuronal and glial diversity along temporal and spatial scales of hypothalamus development3. Here we combine single-cell RNA sequencing of 51,199 mouse cells of ectodermal origin, gene regulatory network (GRN) screens in conjunction with genome-wide association study-based disease phenotyping, and genetic lineage reconstruction to show that nine glial and thirty-three neuronal subtypes are generated by mid-gestation under the control of distinct GRNs. Combinatorial molecular codes that arise from neurotransmitters, neuropeptides and transcription factors are minimally required to decode the taxonomical hierarchy of hypothalamic neurons. The differentiation of γ-aminobutyric acid (GABA) and dopamine neurons, but not glutamate neurons, relies on quasi-stable intermediate states, with a pool of GABA progenitors giving rise to dopamine cells4. We found an unexpected abundance of chemotropic proliferation and guidance cues that are commonly implicated in dorsal (cortical) patterning5 in the hypothalamus. In particular, loss of SLIT-ROBO signalling impaired both the production and positioning of periventricular dopamine neurons. Overall, we identify molecular principles that shape the developmental architecture of the hypothalamus and show how neuronal heterogeneity is transformed into a multimodal neural unit to provide virtually infinite adaptive potential throughout life.


Assuntos
Regulação da Expressão Gênica no Desenvolvimento , Hipotálamo/citologia , Hipotálamo/embriologia , Morfogênese , Animais , Diferenciação Celular , Linhagem da Célula , Dopamina/metabolismo , Neurônios Dopaminérgicos/citologia , Neurônios Dopaminérgicos/metabolismo , Ectoderma/citologia , Ectoderma/metabolismo , Feminino , Neurônios GABAérgicos/citologia , Neurônios GABAérgicos/metabolismo , Redes Reguladoras de Genes , Estudo de Associação Genômica Ampla , Ácido Glutâmico/metabolismo , Hipotálamo/metabolismo , Masculino , Camundongos , Morfogênese/genética , Proteínas do Tecido Nervoso/metabolismo , Neuroglia/citologia , Neuroglia/metabolismo , Neuropeptídeos/metabolismo , Neurotransmissores/metabolismo , Receptores Imunológicos/metabolismo , Regulon/genética , Transdução de Sinais , Fatores de Transcrição/metabolismo , Ácido gama-Aminobutírico/metabolismo
18.
Proc Natl Acad Sci U S A ; 117(24): 13771-13782, 2020 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-32487727

RESUMO

The nucleus accumbens (NAc), a central component of the midbrain dopamine reward circuit, exhibits disturbed circadian rhythms in the postmortem brains of depressed patients. We hypothesized that normal mood regulation requires proper circadian timing in the NAc, and that mood disorders are associated with dysfunctions of the NAc cellular circadian clock. In mice exhibiting stress-induced depression-like behavior (helplessness), we found altered circadian clock function and high nighttime expression of the core circadian clock component CRYPTOCHROME (CRY) in the NAc. In the NAc of helpless mice, we found that higher expression of CRY is associated with decreased activation of dopamine 1 receptor-expressing medium spiny neurons (D1R-MSNs). Furthermore, D1R-MSN-specific CRY-knockdown in the NAc reduced susceptibility to stress-induced helplessness and increased NAc neuronal activation at night. Finally, we show that CRY inhibits D1R-induced G protein activation, likely by interacting with the Gs protein. Altered circadian rhythms and CRY expression were also observed in human fibroblasts from major depressive disorder patients. Our data reveal a causal role for CRY in regulating the midbrain dopamine reward system, and provide a mechanistic link between the NAc circadian clock and vulnerability to depression.


Assuntos
Relógios Circadianos , Criptocromos/metabolismo , Depressão/metabolismo , Núcleo Accumbens/metabolismo , Animais , Comportamento Animal , Depressão/genética , Depressão/fisiopatologia , Depressão/psicologia , Dopamina/metabolismo , Feminino , Desamparo Aprendido , Humanos , Masculino , Camundongos , Neurônios/metabolismo , Receptores Dopaminérgicos/genética , Receptores Dopaminérgicos/metabolismo
19.
Neuron ; 106(5): 703-704, 2020 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-32497503

RESUMO

In this issue of Neuron, Fernandes et al. (2020) compare intra-gastric sugar and non-caloric sweetener to investigate how post-ingestive effects can be reinforcing, revealing a role for the hepatic vagus nerve in transforming sugar sensing by the gut into behavioral reinforcement via midbrain dopamine neuron responses.


Assuntos
Dopamina , Neurônios Dopaminérgicos , Ingestão de Alimentos , Mesencéfalo , Nervo Vago
20.
Chem Biol Interact ; 327: 109164, 2020 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-32524992

RESUMO

General anaesthetics are some of the most widely used and essential therapeutic agents. However, despite over a century of research, the molecular mechanisms of general anaesthesia in the central nervous system remain elusive. Ketamine (ketamine hydrochloride) has been approved for use in general anaesthesia either alone or in combination with other medications. It is a superb drug for use in short-term medical procedures that do not require skeletal muscle relaxation, and it has approval for the induction of general anaesthesia as a pre-anaesthetic to other general anaesthetic agents. However, Several questions remain unsolved, including the exact identification of the neural substrate of consciousness and its components, the pharmacodynamic interactions between anaesthetic agents, the mechanisms of cognitive alterations that follow an anaesthetic procedure, the identification of an eventual unitary mechanism of anaesthesia-induced alteration of consciousness, the relationship between network effects and the biochemical targets of anaesthetic agents, leading to difficulties in between-studies comparisons. Thus, the glutamate and dopamine systems play distinct roles in terms of neuronal signalling, yet both have proposed to contribute significantly to the pathophysiology of neuropsychiatric diseases. Imaging of the glutamate system and other aspects of research on the dopamine system have produced less consistent findings, potentially due to methodological limitations and the heterogeneity of the disorder. In this review, we discuss the neural circuits through which the two systems interact and how their disruption may cause psychotic symptoms. We also summarize from a molecular perspective of mechanisms of action of ketamine as general anaesthetics on ligand-gated ion channels mediated modulation of dopamine in the brain region.


Assuntos
Anestésicos Dissociativos/farmacologia , Dopamina/metabolismo , Ácido Glutâmico/metabolismo , Ketamina/farmacologia , Anestesia/efeitos adversos , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Neurônios Dopaminérgicos/efeitos dos fármacos , Humanos , Transtornos Psicóticos/fisiopatologia , Receptores de N-Metil-D-Aspartato/antagonistas & inibidores , Receptores de N-Metil-D-Aspartato/metabolismo , Esquizofrenia/fisiopatologia
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