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1.
Artigo em Russo | MEDLINE | ID: mdl-31851173

RESUMO

AIM: To study an effect of cabergoline on dopamine and noradrenaline concentration and BDNF mRNA level in the rat midbrain and hypothalamus. MATERIAL AND METHODS: Twenty adult male Wistar rats were used in a single treatment paradigm: animals of the treatment group (n=10) received cabergoline (i.p., 0.5 mg/kg) and the control group (n=10) received an equivalent volume of the solvent. Quantitative analysis for the dopamine (DA) and noradrenaline (NA) was carried out using high-performance liquid chromatography (HPLC) coupled with electrochemical detection. BDNF mRNA levels were studied using quantitative RT-PCR. RESULTS AND CONCLUSION: Cabergoline significantly increases NA concentration in the midbrain 24 hours after injection: 639.2±64.5 ng/g in the treatment group versus 398.0±66.0 ng/g in the control group (p<0.05), while mean content of DA is not significantly changed (211.4±16.3 ng/g vs 169.7±54.6 ng/g, respectively). Cabergoline does not affect hypothalamic DA and NA levels. The drug increases BDNF mRNA levels by 2-times in the midbrain, but not in the hypothalamus, 24 hours after injection.


Assuntos
Fator Neurotrófico Derivado do Encéfalo , Cabergolina , Catecolaminas , Receptores de Dopamina D2 , Animais , Fator Neurotrófico Derivado do Encéfalo/efeitos dos fármacos , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Cabergolina/farmacologia , Catecolaminas/metabolismo , Ergolinas , Hipotálamo/efeitos dos fármacos , Hipotálamo/metabolismo , Masculino , Mesencéfalo/efeitos dos fármacos , Mesencéfalo/metabolismo , RNA Mensageiro , Ratos , Ratos Wistar , Receptores de Dopamina D2/agonistas
2.
Folia Neuropathol ; 57(2): 196-204, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31556578

RESUMO

INTRODUCTION: Exposure to acrylamide is increasing worldwide as a result of its heavy use in industry and formation in carbohydrate-rich food cooked at high temperature. Despite its neurotoxicity, no studies have shown its toxic effects on dopaminergic neurons yet. Therefore, the current study was carried out to show whether acrylamide adversely affects primary cultured dopaminergic neurons. MATERIAL AND METHODS: Acrylamide (0.001, 0.01, 0.1, 1, 2 mM) was added to two different groups of primary mesencephalic cell cultures on the 9th day in vitro for 24 and 48 h, respectively. Moreover, a group of cultures was treated with lower concentrations of acrylamide (0.01, 0.05, 0.1, 0.5 mM) on the 6th day in vitro for 5 consecutive days to investigate its long-term effects on dopaminergic neurons. Following each treatment, culture media were obtained for measuring lactate dehydrogenase, and cultured cells were stained immunocytochemically against tyrosine hydroxylase and neuronal nuclear antigens. RESULTS: Treatment of cultures with acrylamide for 48 h significantly reduced the number of dopaminergic neurons, adversely altered the morphology of the surviving neurons and increased levels of lactate dehydrogenase in the culture media. Similar treatment of cultures with acrylamide also resulted in lower numbers of total neuronal cells as shown by a reduced expression of the neuronal nuclear antigen. Prolonged treatment of cultures with lower concentrations of acrylamide slightly reduced the survival of dopaminergic neurons but increased the release of lactate dehydrogenase into the culture media as well. CONCLUSIONS: The current study shows, for the first time, neurotoxicity of acrylamide on dopaminergic neurons in the primary mesencephalic cell culture.


Assuntos
Acrilamida/toxicidade , Morte Celular/efeitos dos fármacos , Neurônios Dopaminérgicos/efeitos dos fármacos , Mesencéfalo/efeitos dos fármacos , Animais , Células Cultivadas , Neurônios Dopaminérgicos/citologia , L-Lactato Desidrogenase/análise , Mesencéfalo/citologia , Camundongos
3.
Drug Resist Updat ; 44: 15-25, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-31202081

RESUMO

Diffuse midline gliomas (DMG) are rapidly fatal tumors of the midbrain in children, characterized by a diffuse growing pattern and high levels of intrinsic resistance to therapy. The location of these tumors, residing behind the blood-brain barrier (BBB), and the limited knowledge about the biology of these tumors, has hindered the development of effective treatment strategies. However, the introduction of diagnostic biopsies and the implementation of autopsy protocols in several large centers world-wide has allowed for a detailed characterization of these rare tumors. This has resulted in the identification of novel therapeutic targets, as well as major advances in understanding the biology of DMG in relation to therapy resistance. We here provide an overview of the cellular pathways and tumor-specific aberrations that have been targeted in preclinical DMG research, and discuss the advantages and limitations of these therapeutic strategies in relation to therapy resistance and BBB-penetration. Therewith, we aim to provide researchers with a framework for successful preclinical therapy development.


Assuntos
Neoplasias Encefálicas/tratamento farmacológico , Epigênese Genética , Regulação Neoplásica da Expressão Gênica , Glioma/tratamento farmacológico , Terapia de Alvo Molecular/métodos , Proteínas de Neoplasias/genética , Antineoplásicos/uso terapêutico , Barreira Hematoencefálica/efeitos dos fármacos , Barreira Hematoencefálica/metabolismo , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/genética , Criança , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Glioma/genética , Glioma/metabolismo , Glioma/patologia , Histona Desacetilases/genética , Histona Desacetilases/metabolismo , Histonas/genética , Histonas/metabolismo , Humanos , Mesencéfalo/efeitos dos fármacos , Mesencéfalo/metabolismo , Mesencéfalo/patologia , Proteínas de Neoplasias/antagonistas & inibidores , Proteínas de Neoplasias/metabolismo , Transdução de Sinais
4.
Psychopharmacology (Berl) ; 236(9): 2687-2697, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31053935

RESUMO

RATIONALE: Antipsychotics exert therapeutic effects by modulating various cellular signalling pathways and several types of receptors, including PKA- and GSK3ß-mediated signalling pathways, and NMDA receptors. The ventral midbrain, mainly containing the ventral tegmental area (VTA) and substantia nigra (SN), are the nuclei with dopamine origins in the brain, which are also involved in the actions of antipsychotics. Whether antipsychotics can modulate these cellular pathways in the ventral midbrain is unknown. OBJECTIVE: This study aims to investigate the effects of antipsychotics, including aripiprazole (a dopamine D2 receptor (D2R) partial agonist), bifeprunox (a D2R partial agonist), and haloperidol (a D2R antagonist) on the PKA- and GSK3ß-mediated pathways and NMDA receptors in the ventral midbrain. METHODS: Male rats were orally administered aripiprazole (0.75 mg/kg, t.i.d. (ter in die)), bifeprunox (0.8 mg/kg, t.i.d.), haloperidol (0.1 mg/kg, t.i.d.) or vehicle for either 1 week or 10 weeks. The levels of PKA, p-PKA, Akt, p-Akt, GSK3ß, p-GSK3ß, Dvl-3, ß-catenin, and NMDA receptor subunits in the ventral midbrain were assessed by Western Blots. RESULTS: The results showed that chronic antipsychotic treatment with aripiprazole selectively increased PKA activity in the VTA. Additionally, all three drugs elevated the activity of the Akt-GSK3ß signalling pathway in a time-dependent manner, while only aripiprazole stimulated the Dvl-3-GSK3ß-ß-catenin signalling pathway in the SN. Furthermore, chronic administration with both aripiprazole and haloperidol decreased the expression of NMDA receptors. CONCLUSION: This study suggests that activating PKA- and GSK3ß-mediated pathways and downregulating NMDA receptor expression in the ventral midbrain might contribute to the clinical effects of antipsychotics.


Assuntos
Antipsicóticos/administração & dosagem , Proteínas Quinases Dependentes de AMP Cíclico/biossíntese , Glicogênio Sintase Quinase 3 beta/biossíntese , Mesencéfalo/efeitos dos fármacos , Mesencéfalo/metabolismo , Receptores de N-Metil-D-Aspartato/biossíntese , Animais , Antipsicóticos/farmacologia , Ativação Enzimática/efeitos dos fármacos , Ativação Enzimática/fisiologia , Masculino , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Receptores de N-Metil-D-Aspartato/antagonistas & inibidores , Receptores de N-Metil-D-Aspartato/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia , Área Tegmentar Ventral/efeitos dos fármacos , Área Tegmentar Ventral/metabolismo
5.
Bull Exp Biol Med ; 166(6): 709-713, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31020579

RESUMO

An original concept of a two-stage mechanism of positive reinforcement is proposed. The first stage, "virtual" reinforcement, is formed in parallel with the action result acceptor when the result is still not achieved. At this stage, the importance of the planned result and the probability of its achievement are assessed. The greater are these indices, the stronger is "virtual" reinforcement. Hypothetically, the "virtual" reinforcement is mediated by dopamine release from nerve terminals in the mesencephalon. The "real" reinforcement (the second stage) occurs after achievement of the result. Probably, an important role in the mechanisms of the "real" reinforcement is given to endogenous opioids, cannabinoids, and GABA. Based on the advanced hypothesis on interaction between the central and peripheral subdivisions of the corresponding neurochemical systems, the review focuses on possibility of pharmacological intervention into the mechanisms of positive reinforcement by modifying activity of the peripheral opioid and dopamine receptors with the ligands that cannot cross blood-brain barrier.


Assuntos
Retroalimentação Fisiológica/fisiologia , Mesencéfalo/fisiologia , Receptores Dopaminérgicos/fisiologia , Receptores Opioides/fisiologia , Analgésicos Opioides/metabolismo , Analgésicos Opioides/farmacologia , Animais , Canabinoides/metabolismo , Canabinoides/farmacologia , Humanos , Mesencéfalo/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Neurônios/fisiologia , Satisfação Pessoal , Ácido gama-Aminobutírico/metabolismo , Ácido gama-Aminobutírico/farmacologia
6.
Neuroscience ; 406: 278-289, 2019 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-30885640

RESUMO

Methamphetamine (MA), neurotoxic drug of abuse, causes cell death in vitro and in vivo via several mechanisms such as mitochondrial dysfunction. In this study we evaluated the effect of MA on cell viability and mitochondrial biogenesis in primary midbrain culture. Primary mesencephalon cells prepared from E14.5 rat embryo were treated with 0.2-5 mM MA concentrations for 24, 48, and 72 h. Morphological changes of the cells were observed under light microscope. Cell viability and cell death following MA were assessed using MTT assay and immunocytochemistry. Gene expressions of mitochondrial biogenesis-involved factors (PGC1α, NRF1 and TFAM), and neuronal and glial markers were measured by qPCR. Low to moderate MA concentrations elevated cell viability in all time points, while higher concentrations and longer incubation times (48 and 72 h) decreased it. Sphered cell bodies and neurites degeneration were observed following exposure to high MA concentrations. MA at 5 mM concentration decreased the number of ß3-tubulin-, TH-, GFAP- and Iba1-positive cells, and their corresponding mRNA levels; however, 1 mM MA reduced α-synuclein mRNA. Unexpectedly, gene expression of PGC1α, NRF1 and TFAM was increased in response to 5 mM MA, with no changes following 1 mM MA. The results indicated that MA effect on cell viability occurs in a dose-dependent manner. While moderate concentrations increased cell viability, the higher ones reduced it and caused cell death. Mitochondrial biogenesis activation, as a compensatory mechanism, did not prevent neuronal and glial cell death following high MA concentration.


Assuntos
Mesencéfalo/efeitos dos fármacos , Metanfetamina/farmacologia , Mitocôndrias/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Animais , Morte Celular/efeitos dos fármacos , Feminino , Mesencéfalo/metabolismo , Mitocôndrias/metabolismo , Neuritos/efeitos dos fármacos , Neuritos/metabolismo , Neurônios/metabolismo , Síndromes Neurotóxicas/tratamento farmacológico , Biogênese de Organelas , Ratos Wistar , alfa-Sinucleína/efeitos dos fármacos , alfa-Sinucleína/metabolismo
7.
Neuroimage ; 194: 120-127, 2019 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-30914385

RESUMO

Insulin modulates dopamine neuron activity in midbrain and affects processes underlying food intake behaviour, including impulsivity and reward processing. Here, we used intranasal administration and task-free functional MRI in humans to assess time- and dose-dependent effects of insulin on functional connectivity of the dopaminergic midbrain - and how these effects varied depending on systemic insulin sensitivity as measured by HOMA-IR. Specifically, we used a repeated-measures design with factors dose (placebo, 40 IU, 100 IU, 160 IU), time (7 time points during a 90 min post-intervention interval), and group (low vs. high HOMA-IR). A factorial analysis identified a three-way interaction (with whole-brain significance) with regard to functional connectivity between midbrain and the ventromedial prefrontal cortex. This interaction demonstrates that systemic insulin sensitivity modulates the temporal course and dose-dependent effects of intranasal insulin on midbrain functional connectivity. It suggests that altered insulin sensitivity may impact on dopaminergic projections of the midbrain and might underlie the dysregulation of reward-related and motivational behaviour in obesity and diabetes. Perhaps most importantly, the time courses of midbrain functional connectivity we present may provide useful guidance for the design of future human studies that utilize intranasal insulin administration.


Assuntos
Hipoglicemiantes/administração & dosagem , Insulina/administração & dosagem , Mesencéfalo/efeitos dos fármacos , Administração Intranasal , Adulto , Relação Dose-Resposta a Droga , Humanos , Resistência à Insulina/fisiologia , Imagem por Ressonância Magnética , Masculino , Sobrepeso
8.
Int J Mol Sci ; 20(3)2019 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-30704073

RESUMO

In previous studies, we found regional differences in the induction of antioxidative molecules in astrocytes against oxidative stress, postulating that region-specific features of astrocytes lead region-specific vulnerability of neurons. We examined region-specific astrocytic features against dopaminergic neurotoxin 6-hydroxydopamine (6-OHDA) as an oxidative stress using co-culture of mesencephalic neurons and mesencephalic or striatal astrocytes in the present study. The 6-OHDA-induced reduction of mesencephalic dopamine neurons was inhibited by co-culturing with astrocytes. The co-culture of midbrain neurons with striatal astrocytes was more resistant to 6-OHDA than that with mesencephalic astrocytes. Furthermore, glia conditioned medium from 6-OHDA-treated striatal astrocytes showed a greater protective effect on the 6-OHDA-induced neurotoxicity and oxidative stress than that from mesencephalic astrocytes. The cDNA microarray analysis showed that the number of altered genes in both mesencephalic and striatal astrocytes was fewer than that changed in either astrocyte. The 6-OHDA treatment, apparently up-regulated expressions of Nrf2 and some anti-oxidative or Nrf2-regulating phase II, III detoxifying molecules related to glutathione synthesis and export in the striatal astrocytes but not mesencephalic astrocytes. There is a profound regional difference of gene expression in astrocytes induced by 6-OHDA. These results suggest that protective features of astrocytes against oxidative stress are more prominent in striatal astrocytes, possibly by secreting humoral factors in striatal astrocytes.


Assuntos
Astrócitos/efeitos dos fármacos , Astrócitos/metabolismo , Oxidopamina/farmacologia , Animais , Células Cultivadas , Técnicas de Cocultura , Meios de Cultivo Condicionados , Neurônios Dopaminérgicos/efeitos dos fármacos , Neurônios Dopaminérgicos/metabolismo , Mesencéfalo/citologia , Mesencéfalo/efeitos dos fármacos , Neuroproteção/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley
9.
Neuropsychopharmacology ; 44(2): 344-355, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30054584

RESUMO

Astrocytes are ubiquitous CNS cells that support tissue homeostasis through ion buffering, neurotransmitter recycling, and regulation of CNS vasculature. Yet, despite the essential functional roles they fill, very little is known about the physiology of astrocytes in the ventral midbrain, a region that houses dopamine-releasing neurons and is critical for reward learning and motivated behaviors. Here, using a combination of whole-transcriptome sequencing, histology, slice electrophysiology, and calcium imaging, we performed the first functional and molecular profiling of ventral midbrain astrocytes and observed numerous differences between these cells and their telencephalic counterparts, both in their gene expression profile and in their physiological properties. Ventral midbrain astrocytes have very low membrane resistance and inward-rectifying potassium channel-mediated current, and are extensively coupled to surrounding oligodendrocytes through gap junctions. They exhibit calcium responses to glutamate but are relatively insensitive to norepinephrine. In addition, their calcium activity can be dynamically modulated by dopamine D2 receptor signaling. Taken together, these data indicate that ventral midbrain astrocytes are physiologically distinct from astrocytes in cortex and hippocampus. This work provides new insights into the extent of functional astrocyte heterogeneity within the adult brain and establishes the foundation for examining the impact of regional astrocyte differences on dopamine neuron function and susceptibility to degeneration.


Assuntos
Astrócitos/fisiologia , Córtex Cerebral/metabolismo , Mesencéfalo/metabolismo , Receptores de Dopamina D2/metabolismo , Animais , Astrócitos/citologia , Astrócitos/efeitos dos fármacos , Cálcio/metabolismo , Forma Celular/fisiologia , Córtex Cerebral/citologia , Córtex Cerebral/efeitos dos fármacos , Feminino , Junções Comunicantes/metabolismo , Ácido Glutâmico/farmacologia , Masculino , Mesencéfalo/citologia , Mesencéfalo/efeitos dos fármacos , Camundongos , Norepinefrina/farmacologia
10.
Pharmacol Biochem Behav ; 178: 19-29, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-29782942

RESUMO

Different timing and light phases are critical factors in behavioural neuroscience, which can greatly affect the experimental outcomes of the performed tests. Despite the fact that time of testing is one of the most common factors that varies across behavioural laboratories, knowledge about the consequences of testing time on behavioural readouts is limited. Thus, in this study we systematically assessed the effect of this factor on the readout of a variety of elementary and recurrent behavioural paradigms in C57Bl/6 mice. Furthermore, we investigated potential neuronal correlates of this phenomenon by analysing how testing time influences the expression pattern of genes relevant for neuronal activation functions and the control of brain circadian rhythms. We show that animals tested in the light phase display reduced social approach behaviour and sensorimotor gating and increased locomotor activity, whereas anxiety-related behaviour and working memory are not affected. In addition, animals tested in the light phase also exhibit increased locomotor response to systemic amphetamine treatment, which is paralleled by alterations in the expression patterns of tyrosine hydroxylase (TH) and dopamine transporter (DAT) in the Nucleus Accumbens (NAc) and/or Midbrain (Mid). Lastly, we observed that neuronal activation, indexed by the gene expression levels of cFos, was increased in the NAc and Mid of animals tested during the light phase. Our data thus suggest that daily alterations in gene expression in mesolimbic brain structures might be involved in the different behavioural responses of mice tested in the light- versus the dark-phase. At the same time, our study adds further weight to the notion that the specific timing of testing can indeed strongly affect the readout of a given test. As comparison and reproducibility of findings is pivotal in science, experimental protocols should be clarified in detail to allow appropriate data comparison across different laboratories.


Assuntos
Comportamento Animal/fisiologia , Ritmo Circadiano/fisiologia , Fotoperíodo , Anfetamina/administração & dosagem , Anfetamina/farmacologia , Animais , Ansiedade/psicologia , Estudos de Coortes , Proteínas da Membrana Plasmática de Transporte de Dopamina/genética , Feminino , Expressão Gênica/efeitos dos fármacos , Locomoção/efeitos dos fármacos , Masculino , Memória de Curto Prazo , Mesencéfalo/efeitos dos fármacos , Mesencéfalo/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Núcleo Accumbens/efeitos dos fármacos , Núcleo Accumbens/metabolismo , Proteínas Proto-Oncogênicas c-fos/genética , Reflexo de Sobressalto , Comportamento Social , Tirosina 3-Mono-Oxigenase/genética
11.
Hum Exp Toxicol ; 38(2): 173-184, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30001633

RESUMO

Parkinson's disease (PD) is the second most common age-related neurodegenerative disease after Alzheimer's disease, characterized by loss of dopaminergic neurons in substantia nigra pars compacta, accompanied by motor and nonmotor symptoms. The neuropathological hallmarks of PD are well reported, but the etiology of the disease is still undefined; several studies assume that oxidative stress, mitochondrial defects, and neuroinflammation play vital roles in the progress of the disease. The current study was established to investigate the neuroprotective effect of agmatine on a rotenone (ROT)-induced experimental model of PD. Adult male Sprague Dawley rats were subcutaneously injected with ROT at a dose of 2 mg/kg body weight for 35 days. Agmatine was injected intraperitoneally at 50 and 100 mg/kg body weight, 1 h prior to ROT administration. ROT-treated rats that received agmatine showed better performance on beam walking and an elevated number of rears within the cylinder test. In addition, agmatine reduced midbrain malondialdehyde as an indication of lipid peroxidation, pro-inflammatory cytokines including tumor necrosis factor alpha and interleukin-1ß, and glial fibrillary acidic protein. Moreover, agmatine was responsible for preventing loss of tyrosine hydroxylase-positive neurons. In conclusion, our study showed that agmatine possesses a dose-dependent neuroprotective effect through its antioxidant and anti-inflammatory activities. These findings need further clinical investigations of agmatine as a promising neuroprotective agent for the future treatment of PD.


Assuntos
Agmatina/uso terapêutico , Fármacos Neuroprotetores/uso terapêutico , Doença de Parkinson Secundária/tratamento farmacológico , Agmatina/farmacologia , Animais , Citocinas/metabolismo , Modelos Animais de Doenças , Proteína Glial Fibrilar Ácida/metabolismo , Glutationa/metabolismo , Masculino , Malondialdeído/metabolismo , Mesencéfalo/efeitos dos fármacos , Mesencéfalo/metabolismo , Fármacos Neuroprotetores/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Doença de Parkinson Secundária/induzido quimicamente , Doença de Parkinson Secundária/metabolismo , Ratos Sprague-Dawley , Rotenona , Tirosina 3-Mono-Oxigenase/metabolismo
12.
Neuroscience ; 396: 108-118, 2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-30439538

RESUMO

Panic disorder (PD), a prevalent anxiety disorder, is characterized by unexpected panic attacks, persistent anxiety and avoidance of panic contexts. Selective serotonin reuptake inhibitors (SSRIs) are effective in treating PD; however, the mechanisms underlying SSRI efficacy are poorly understood. Using CO2-inhalation, a PD-relevant translational paradigm, we examined the effect of chronic SSRI (fluoxetine) treatment on unconditioned and context-conditioned defensive behaviors, as well as respiratory responses, in mice. In addition, cFos expression was evaluated as a measure of the functional activity and interregional correlation matrices were used to explore the neurocircuitry recruited in CO2-conditioned behavior and SSRI treatment response. Chronic fluoxetine attenuated CO2-induced passive (freezing) behavior during inhalation and active (rearing) behavior on re-exposure to context, in addition to reducing CO2-evoked respiratory responses. Brain mapping in CO2-context-conditioned mice revealed altered regional neuronal activation within and correlations across midbrain regions subserving defensive behaviors (periaqueductal gray (PAG) and raphe nuclei) and forebrain emotional and contextual processing loci (medial prefrontal cortex, insular cortex and hippocampus). Importantly, fluoxetine treatment normalized these alterations. Collectively, our results provide novel information on fluoxetine modulation of panic-relevant defensive behaviors and neurocircuitry, facilitating increased understanding of panic neurobiology in the context of treatment response.


Assuntos
Dióxido de Carbono/metabolismo , Fluoxetina/farmacologia , Mesencéfalo/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Prosencéfalo/efeitos dos fármacos , Respiração/efeitos dos fármacos , Administração por Inalação , Animais , Resposta de Imobilidade Tônica/efeitos dos fármacos , Masculino , Mesencéfalo/citologia , Camundongos , Atividade Motora/efeitos dos fármacos , Neurônios/metabolismo , Prosencéfalo/citologia , Proteínas Proto-Oncogênicas c-fos/metabolismo
13.
Neuroscience ; 396: 79-93, 2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-30458220

RESUMO

Prenatal exposure to the antiepileptic valproic acid (VPA) is associated with an increased risk of autism spectrum disorder (ASD) in humans and is used as an animal model of ASD. The majority of individuals with ASD exhibit adverse reactions to sensory stimuli and auditory dysfunction. Previous studies of animals exposed to VPA reveal abnormal neuronal responses to sound and mapping of sound frequency in the cerebral cortex and hyperactivation, hypoplasia and abnormal neuronal morphology in the cochlear nuclei (CN) and superior olivary complex (SOC). Herein, we examine the neuronal populations in the lateral lemniscus and inferior colliculus in animals exposed in utero to VPA. We used a combination of morphometric techniques, histochemistry and immunofluorescence to examine the nuclei of the lateral lemniscus (NLL) and the central nucleus of the inferior colliculus (CNIC). We found that the VPA exposure resulted in larger neurons in the CNIC and the dorsal nucleus of the lateral lemniscus (DNLL). However, we found that there were significantly fewer neurons throughout all nuclei examined in the auditory brainstem of VPA-exposed animals. Additionally, we found significantly fewer calbindin-immunopositive neurons in the DNLL. VPA exposure had no impact on the proportions of perineuronal nets in the NLL or CNIC. Finally, consistent with our observations in the CN and SOC, VPA exposure resulted in fewer dopaminergic terminals in the CNIC. Together, these results indicate that in utero VPA exposure significantly impacts structure and function of nearly the entire central auditory pathway.


Assuntos
Vias Auditivas/efeitos dos fármacos , Mesencéfalo/efeitos dos fármacos , Mesencéfalo/patologia , Neurônios/efeitos dos fármacos , Neurônios/patologia , Efeitos Tardios da Exposição Pré-Natal/induzido quimicamente , Efeitos Tardios da Exposição Pré-Natal/patologia , Ácido Valproico/efeitos adversos , Animais , Transtorno do Espectro Autista/patologia , Calbindinas/metabolismo , Contagem de Células , Neurônios Dopaminérgicos/patologia , Feminino , Colículos Inferiores/efeitos dos fármacos , Colículos Inferiores/patologia , Masculino , Neurônios/metabolismo , Gravidez , Ratos
14.
Neurochem Res ; 44(2): 412-420, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30488363

RESUMO

We studied Ang II receptor localization in different nuclei of the auditory system, by means of binding autoradiography, during brain development. The inferior colliculus (IC), a large midbrain structure which serves as an obligatory synaptic station in both the ascending and descending auditory pathways, exhibited high Ang II AT2 binding at all ages (P0, P8, P15, P30), being maximal at P15. These observations were confirmed by in situ hybridization and immunofluorescence at P15, demonstrating that AT2 receptor mRNA localized at the same area recognized by AT2 antibodies and anti ß III-tubulin suggesting the neuronal nature of the reactive cells. Ang II AT1 receptors were absent at early developmental ages (P0) in all nuclei of the auditory system and a low level was observed in the IC at the age P8. AT2 receptors were present at ventral cochlear nucleus and superior olivary complex, being higher at P15 and P8, respectively. We also explored the effect of prenatal administration of Ang II or PD123319 (AT2 antagonist) on binding of Ang II receptors at P0, P8, P15. Both treatments increased significantly the level of AT2 receptors at P0 and P8 in the IC. Although total binding in the whole IC from P15 animals showed no difference between treatments, the central nucleus of the IC exhibited higher binding. Our results supports a correlation between the timing of the higher expression of Ang II AT2 receptors in different nuclei, the onset of audition and the establishment of neuronal circuits of the auditory pathway.


Assuntos
Angiotensina II/efeitos dos fármacos , Vias Auditivas/efeitos dos fármacos , Vias Auditivas/metabolismo , Imidazóis/farmacologia , Piridinas/farmacologia , Receptor Tipo 1 de Angiotensina/efeitos dos fármacos , Fatores Etários , Angiotensina II/metabolismo , Animais , Autorradiografia/métodos , Feminino , Mesencéfalo/efeitos dos fármacos , Mesencéfalo/metabolismo , Gravidez , Ratos Wistar , Receptor Tipo 1 de Angiotensina/metabolismo
15.
Nat Commun ; 9(1): 4815, 2018 11 16.
Artigo em Inglês | MEDLINE | ID: mdl-30446643

RESUMO

Common disorders, including diabetes and Parkinson's disease, are caused by a combination of environmental factors and genetic susceptibility. However, defining the mechanisms underlying gene-environment interactions has been challenging due to the lack of a suitable experimental platform. Using pancreatic ß-like cells derived from human pluripotent stem cells (hPSCs), we discovered that a commonly used pesticide, propargite, induces pancreatic ß-cell death, a pathological hallmark of diabetes. Screening a panel of diverse hPSC-derived cell types we extended this observation to a similar susceptibility in midbrain dopamine neurons, a cell type affected in Parkinson's disease. We assessed gene-environment interactions using isogenic hPSC lines for genetic variants associated with diabetes and Parkinson's disease. We found GSTT1-/- pancreatic ß-like cells and dopamine neurons were both hypersensitive to propargite-induced cell death. Our study identifies an environmental chemical that contributes to human ß-cell and dopamine neuron loss and validates a novel hPSC-based platform for determining gene-environment interactions.


Assuntos
Cicloexanos/toxicidade , Diabetes Mellitus/induzido quimicamente , Neurônios Dopaminérgicos/efeitos dos fármacos , Interação Gene-Ambiente , Células Secretoras de Insulina/efeitos dos fármacos , Praguicidas/toxicidade , Animais , Morte Celular/efeitos dos fármacos , Morte Celular/genética , Diferenciação Celular , Diabetes Mellitus/genética , Diabetes Mellitus/patologia , Neurônios Dopaminérgicos/citologia , Neurônios Dopaminérgicos/enzimologia , Glutationa Transferase/deficiência , Glutationa Transferase/genética , Humanos , Células Secretoras de Insulina/citologia , Células Secretoras de Insulina/enzimologia , Mesencéfalo/citologia , Mesencéfalo/efeitos dos fármacos , Mesencéfalo/enzimologia , Camundongos , Modelos Biológicos , Doença de Parkinson/etiologia , Doença de Parkinson/genética , Doença de Parkinson/patologia , Células-Tronco Pluripotentes/citologia , Células-Tronco Pluripotentes/enzimologia
16.
Proc Natl Acad Sci U S A ; 115(43): 11078-11083, 2018 10 23.
Artigo em Inglês | MEDLINE | ID: mdl-30297409

RESUMO

In the descending analgesia pathway, opioids are known to disinhibit the projections from the periaqueductal gray (PAG) to the rostral ventromedial medulla (RVM), leading to suppression of pain signals at the spinal cord level. The locus coeruleus (LC) has been proposed to engage in the descending pathway through noradrenergic inputs to the spinal cord. Nevertheless, how the LC is integrated in the descending analgesia circuit has remained unknown. Here, we show that the opioidergic analgesia pathway is bifurcated in structure and function at the PAG. A knockout as well as a PAG-specific knockdown of phospholipase C ß4 (PLCß4), a signaling molecule for G protein-coupled receptors, enhanced swim stress-induced and morphine-induced analgesia in mice. Immunostaining after simultaneous retrograde labeling from the RVM and the LC revealed two mutually exclusive neuronal populations at the PAG, each projecting either to the LC or the RVM, with PLCß4 expression only in the PAG-LC projecting cells that provide a direct synaptic input to LC-spinal cord (SC) projection neurons. The PAG-LC projection neurons in wild-type mice turned quiescent in response to opiates, but remained active in the PLCß4 mutant, suggesting a possibility that an increased adrenergic function induced by the persistent PAG-LC activity underlies the enhanced opioid analgesia in the mutant. Indeed, the enhanced analgesia in the mutant was reversed by blocking α2-noradrenergic receptors. These findings indicate that opioids suppress descending analgesia through the PAG-LC pathway, while enhancing it through the PAG-RVM pathway, i.e., two distinct pathways with opposing effects on opioid analgesia. These results point to a therapeutic target in pain control.


Assuntos
Analgesia/métodos , Mesencéfalo/fisiopatologia , Manejo da Dor/métodos , Analgésicos Opioides/farmacologia , Animais , Masculino , Mesencéfalo/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Morfina/farmacologia , Vias Neurais/efeitos dos fármacos , Vias Neurais/fisiologia , Neurônios/efeitos dos fármacos , Neurônios/fisiologia , Dor/fisiopatologia , Medula Espinal/efeitos dos fármacos , Medula Espinal/fisiologia , Yin-Yang
17.
J Neurosci ; 38(47): 10080-10092, 2018 11 21.
Artigo em Inglês | MEDLINE | ID: mdl-30282729

RESUMO

Sleep-wake behavior is controlled by a wide range of neuronal populations in the mammalian brain. Although the ventral midbrain/pons (VMP) area is suggested to participate in sleep-wake regulation, the neuronal mechanisms have remained unclear. Here, we found that nonspecific cell ablation or selective ablation of GABAergic neurons by expressing diphtheria toxin fragment A in the VMP in male mice induced a large increase in wakefulness that lasted at least 4 weeks. In contrast, selective ablation of dopaminergic neurons in the VMP had little effect on wakefulness. Chemogenetic inhibition of VMP GABAergic neurons also markedly increased wakefulness. The wake-promoting effect of the VMP GABAergic neuron ablation or inhibition was attenuated to varying degrees by the administration of dopamine D1 or D2/3 receptor antagonists and abolished by the administration of both antagonists together. In contrast, chemogenetic activation of VMP GABAergic neurons very strongly increased slow-wave sleep and reduced wakefulness. These findings suggest that VMP GABAergic neurons regulate dopaminergic actions in the sleep-wake behavior of mice.SIGNIFICANCE STATEMENT Current understanding of the neuronal mechanisms and populations that regulate sleep-wake behavior is incomplete. Here, we identified a GABAergic ventral midbrain/pons area that is necessary for controlling the daily amount of sleep and wakefulness in mice. We also found that these inhibitory neurons control wakefulness by suppressing dopaminergic systems. Surprisingly, activation of these neurons strongly induced slow-wave sleep while suppressing wakefulness. Our study reveals a new brain mechanism critical for sleep-wake regulation.


Assuntos
Neurônios GABAérgicos/fisiologia , Mesencéfalo/fisiologia , Ponte/fisiologia , Sono/fisiologia , Vigília/fisiologia , Animais , Antagonistas de Dopamina/farmacologia , Eletroencefalografia/métodos , Neurônios GABAérgicos/efeitos dos fármacos , Masculino , Mesencéfalo/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Ponte/efeitos dos fármacos , Sono/efeitos dos fármacos , Vigília/efeitos dos fármacos
18.
JAMA Psychiatry ; 75(11): 1107-1117, 2018 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-30167644

RESUMO

Importance: Cannabidiol (CBD) has antipsychotic effects in humans, but how these are mediated in the brain remains unclear. Objective: To investigate the neurocognitive mechanisms that underlie the therapeutic effects of CBD in psychosis. Design, Setting, and Participants: In this parallel-group, double-blind, placebo-controlled randomized clinical trial conducted at the South London and Maudsley NHS Foundation Trust in London, United Kingdom, 33 antipsychotic medication-naive participants at clinical high risk (CHR) of psychosis and 19 healthy control participants were studied. Data were collected from July 2013 to October 2016 and analyzed from November 2016 to October 2017. Interventions: A total of 16 participants at CHR of psychosis received a single oral dose of 600 mg of CBD, and 17 participants at CHR received a placebo. Control participants were not given any drug. All participants were then studied using functional magnetic resonance imaging (fMRI) while performing a verbal learning task. Main Outcomes and Measures: Brain activation during verbal encoding and recall, indexed using the blood oxygen level-dependent hemodynamic response fMRI signal. Results: Of the 16 participants in the CBD group, 6 (38%) were female, and the mean (SD) age was 22.43 (4.95) years; of 17 in the placebo group, 10 (59%) were female, and the mean (SD) age was 25.35 (5.24) years; and of 19 in the control group, 8 (42%) were female, and the mean (SD) age was 23.89 (4.14) years. Brain activation (indexed using the median sum of squares ratio of the blood oxygen level-dependent hemodynamic response effects model component to the residual sum of squares) was analyzed in 15 participants in the CBD group, 16 in the placebo group, and 19 in the control group. Participants receiving placebo had reduced activation relative to controls in the right caudate during encoding (placebo: median, -0.027; interquartile range [IQR], -0.041 to -0.016; control: median, 0.020; IQR, -0.022 to 0.056; P < .001) and in the parahippocampal gyrus and midbrain during recall (placebo: median, 0.002; IQR, -0.016 to 0.010; control: median, 0.035; IQR, 0.015 to 0.039; P < .001). Within these 3 regions, activation in the CBD group was greater than in the placebo group but lower than in the control group (parahippocampal gyrus/midbrain: CBD: median, -0.013; IQR, -0.027 to 0.002; placebo: median, -0.007; IQR, -0.019 to 0.008; control: median, 0.034; IQR, 0.005 to 0.059); the level of activation in the CBD group was thus intermediate to that in the other 2 groups. There were no significant group differences in task performance. Conclusions and Relevance: Cannabidiol may partially normalize alterations in parahippocampal, striatal, and midbrain function associated with the CHR state. As these regions are critical to the pathophysiology of psychosis, the influence of CBD at these sites could underlie its therapeutic effects on psychotic symptoms. Trial Registration: isrctn.org Identifier: ISRCTN46322781.


Assuntos
Canabidiol/farmacologia , Corpo Estriado/efeitos dos fármacos , Rememoração Mental/efeitos dos fármacos , Mesencéfalo/efeitos dos fármacos , Transtornos Psicóticos/tratamento farmacológico , Adulto , Canabidiol/administração & dosagem , Corpo Estriado/diagnóstico por imagem , Método Duplo-Cego , Feminino , Humanos , Análise dos Mínimos Quadrados , Imagem por Ressonância Magnética , Masculino , Mesencéfalo/diagnóstico por imagem , Giro Para-Hipocampal/diagnóstico por imagem , Giro Para-Hipocampal/efeitos dos fármacos , Transtornos Psicóticos/prevenção & controle , Adulto Jovem
19.
Free Radic Biol Med ; 129: 73-87, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30176346

RESUMO

Wnts and the components of Wnt/ß-catenin signaling are widely expressed in midbrain and required to control the fate specification of dopaminergic (DAergic) neurons, a neuronal population that specifically degenerate in Parkinson's disease (PD). Accumulating evidence suggest that mitochondrial dysfunction plays a key role in pathogenesis of PD. Axin-2, a negative regulator of Wnt/ß-catenin signaling affects mitochondrial biogenesis and death/birth of new DAergic neurons is not fully explored. We investigated the functional role of Axin-2/Wnt/ß-catenin signaling in mitochondrial biogenesis and DAergic neurogenesis in 6-hydroxydopamine (6-OHDA) induced rat model of PD-like phenotypes. We demonstrate that single unilateral injection of 6-OHDA into the medial forebrain bundle (MFB) potentially dysregulates Wnt/ß-catenin signaling in substantia nigra pars compacta (SNpc). We used shRNA lentiviruses to genetically knockdown Axin-2 to up-regulate Wnt/ß-catenin signaling in SNpc in parkinsonian rats. Genetic knockdown of Axin-2 up-regulates Wnt/ß-catenin signaling by destabilizing the ß-catenin degradation complex in SNpc in parkinsonian rats. Axin-2 shRNA mediated activation of Wnt/ß-catenin signaling improved behavioural functions and protected the nigral DAergic neurons by increasing mitochondrial functionality in parkinsonian rats. Axin-2 shRNA treatment reduced apoptotic signaling, autophagy and ROS generation and improved mitochondrial membrane potential which promotes mitochondrial biogenesis in SNpc in parkinsonian rats. Interestingly, Axin-2 shRNA-mediated up-regulation of Wnt/ß-catenin signaling enhanced net DAergic neurogenesis by regulating proneural genes (Nurr-1, Pitx-3, Ngn-2, and NeuroD1) and mitochondrial biogenesis in SNpc in parkinsonian rats. Therefore, our data suggest that pharmacological/genetic manipulation of Wnt signaling that enhances the endogenous regenerative capacity of DAergic neurons may have implication for regenerative approaches in PD.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas de Transporte/genética , Neurônios Dopaminérgicos/metabolismo , Neurogênese/genética , Doença de Parkinson Secundária/genética , Proteínas Wnt/genética , Via de Sinalização Wnt , beta Catenina/genética , Proteínas Adaptadoras de Transdução de Sinal/antagonistas & inibidores , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Proteínas de Transporte/antagonistas & inibidores , Proteínas de Transporte/metabolismo , Neurônios Dopaminérgicos/efeitos dos fármacos , Neurônios Dopaminérgicos/patologia , Regulação da Expressão Gênica , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Injeções Intraventriculares , Masculino , Feixe Prosencefálico Mediano/efeitos dos fármacos , Feixe Prosencefálico Mediano/metabolismo , Feixe Prosencefálico Mediano/patologia , Mesencéfalo/efeitos dos fármacos , Mesencéfalo/metabolismo , Mesencéfalo/patologia , Mitocôndrias/genética , Mitocôndrias/metabolismo , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Membro 2 do Grupo A da Subfamília 4 de Receptores Nucleares/genética , Membro 2 do Grupo A da Subfamília 4 de Receptores Nucleares/metabolismo , Biogênese de Organelas , Oxidopamina/administração & dosagem , Doença de Parkinson Secundária/induzido quimicamente , Doença de Parkinson Secundária/metabolismo , Doença de Parkinson Secundária/patologia , Parte Compacta da Substância Negra/efeitos dos fármacos , Parte Compacta da Substância Negra/metabolismo , Parte Compacta da Substância Negra/patologia , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Ratos , Ratos Sprague-Dawley , Técnicas Estereotáxicas , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteínas Wnt/metabolismo , beta Catenina/metabolismo
20.
Mol Pharmacol ; 94(4): 1220-1231, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30115672

RESUMO

Recent meta-analyses found an association between prenatal exposure to the antidepressant fluoxetine (FLX) and an increased risk of autism in children. This developmental disorder has been related to dysfunctions in the brains' rewards circuitry, which, in turn, has been linked to dysfunctions in dopaminergic (DA) signaling. The present study investigated if FLX affects processes involved in dopaminergic neuronal differentiation. Mouse neuronal precursors were differentiated into midbrain dopaminergic precursor cells (mDPCs) and concomitantly exposed to clinically relevant doses of FLX. Subsequently, dopaminergic precursors were evaluated for expression of differentiation and stemness markers using quantitative polymerase chain reaction. FLX treatment led to increases in early regional specification markers orthodenticle homeobox 2 (Otx2) and homeobox engrailed-1 and -2 (En1 and En2). On the other hand, two transcription factors essential for midbrain dopaminergic (mDA) neurogenesis, LIM homeobox transcription factor 1 α (Lmx1a) and paired-like homeodomain transcription factor 3 (Pitx3) were downregulated by FLX treatment. The stemness marker nestin (Nes) was increased, whereas the neuronal differentiation marker ß3-tubulin (Tubb3) decreased. Additionally, we observed that FLX modulates the expression of several genes associated with autism spectrum disorder and downregulates the estrogen receptors (ERs) α and ß Further investigations using ERß knockout (BERKO) mDPCs showed that FLX had no or even opposite effects on several of the genes analyzed. These findings suggest that FLX affects differentiation of the dopaminergic system by increasing production of dopaminergic precursors, yet decreasing their maturation, partly via interference with the estrogen system.


Assuntos
Diferenciação Celular/efeitos dos fármacos , Neurônios Dopaminérgicos/efeitos dos fármacos , Fluoxetina/farmacologia , Mesencéfalo/efeitos dos fármacos , Animais , Transtorno do Espectro Autista/metabolismo , Células Cultivadas , Dopamina/metabolismo , Neurônios Dopaminérgicos/metabolismo , Regulação para Baixo/efeitos dos fármacos , Receptor alfa de Estrogênio/metabolismo , Receptor beta de Estrogênio/metabolismo , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Proteínas de Homeodomínio/metabolismo , Mesencéfalo/metabolismo , Camundongos , Neurogênese/efeitos dos fármacos , Fatores de Transcrição Otx/metabolismo , Transdução de Sinais/efeitos dos fármacos , Fatores de Transcrição/metabolismo , Tubulina (Proteína)/metabolismo
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