Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 50
Filtrar
Mais filtros

Tipo de documento
Intervalo de ano de publicação
1.
Brain ; 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38769595

RESUMO

Altered development and function of the prefrontal cortex (PFC) during adolescence is implicated in the origin of mental disorders. Deficits in the GABAergic system prominently contribute to these alterations. Nav1.1 is a voltage-gated Na+ channel critical for normal GABAergic activity. Here, we studied the role of Nav1.1 in PFC function and its potential relationship with the aetiology of mental disorders. Dysfunction of Nav1.1 activity in the medial PFC (mPFC) of adolescent mice enhanced the local excitation/inhibition ratio, resulting in epileptic activity, cognitive deficits and depressive-like behaviour in adulthood, along with a gene expression profile linked to major depressive disorder (MDD). Additionally, it reduced extracellular serotonin concentration in the dorsal raphe nucleus and brain-derived neurotrophic factor expression in the hippocampus, two MDD-related brain areas beyond the PFC. We also observed alterations in oscillatory activity and impaired hippocampal-mPFC coherence during sleep. Finally, we found reduced expression levels of SCN1A, the gene encoding Nav1.1, in post-mortem PFC samples from human MDD subjects. Collectively, our results provide a novel mechanistic framework linking adolescence-specific alterations in Nav1.1 function in the PFC to the pathogenesis of epilepsy and comorbidities such as cognitive impairment and depressive disorders.

2.
Int J Mol Sci ; 24(5)2023 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-36902322

RESUMO

The reciprocal connectivity between the medial prefrontal cortex (mPFC) and the dorsal raphe nucleus (DR) is involved in mood control and resilience to stress. The infralimbic subdivision (IL) of the mPFC is the rodent equivalent of the ventral anterior cingulate cortex, which is intimately related to the pathophysiology/treatment of major depressive disorder (MDD). Boosting excitatory neurotransmission in the IL-but not in the prelimbic cortex, PrL-evokes depressive-like or antidepressant-like behaviors in rodents, which are associated with changes in serotonergic (5-HT) neurotransmission. We therefore examined the control of 5-HT activity by both of the mPFC subdivisions in anesthetized rats. The electrical stimulation of IL and PrL at 0.9 Hz comparably inhibited 5-HT neurons (53% vs. 48%, respectively). However, stimulation at higher frequencies (10-20 Hz) revealed a greater proportion of 5-HT neurons sensitive to IL than to PrL stimulation (86% vs. 59%, at 20 Hz, respectively), together with a differential involvement of GABAA (but not 5-HT1A) receptors. Likewise, electrical and optogenetic stimulation of IL and PrL enhanced 5-HT release in DR in a frequency-dependent manner, with greater elevations after IL stimulation at 20 Hz. Hence, IL and PrL differentially control serotonergic activity, with an apparent superior role of IL, an observation that may help to clarify the brain circuits involved in MDD.


Assuntos
Transtorno Depressivo Maior , Núcleo Dorsal da Rafe , Ratos , Animais , Córtex Cerebral , Neurônios , Córtex Pré-Frontal/fisiologia
3.
Remote Sens Environ ; 280: 113198, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36090616

RESUMO

Remote detection and monitoring of the vegetation responses to stress became relevant for sustainable agriculture. Ongoing developments in optical remote sensing technologies have provided tools to increase our understanding of stress-related physiological processes. Therefore, this study aimed to provide an overview of the main spectral technologies and retrieval approaches for detecting crop stress in agriculture. Firstly, we present integrated views on: i) biotic and abiotic stress factors, the phases of stress, and respective plant responses, and ii) the affected traits, appropriate spectral domains and corresponding methods for measuring traits remotely. Secondly, representative results of a systematic literature analysis are highlighted, identifying the current status and possible future trends in stress detection and monitoring. Distinct plant responses occurring under shortterm, medium-term or severe chronic stress exposure can be captured with remote sensing due to specific light interaction processes, such as absorption and scattering manifested in the reflected radiance, i.e. visible (VIS), near infrared (NIR), shortwave infrared, and emitted radiance, i.e. solar-induced fluorescence and thermal infrared (TIR). From the analysis of 96 research papers, the following trends can be observed: increasing usage of satellite and unmanned aerial vehicle data in parallel with a shift in methods from simpler parametric approaches towards more advanced physically-based and hybrid models. Most study designs were largely driven by sensor availability and practical economic reasons, leading to the common usage of VIS-NIR-TIR sensor combinations. The majority of reviewed studies compared stress proxies calculated from single-source sensor domains rather than using data in a synergistic way. We identified new ways forward as guidance for improved synergistic usage of spectral domains for stress detection: (1) combined acquisition of data from multiple sensors for analysing multiple stress responses simultaneously (holistic view); (2) simultaneous retrieval of plant traits combining multi-domain radiative transfer models and machine learning methods; (3) assimilation of estimated plant traits from distinct spectral domains into integrated crop growth models. As a future outlook, we recommend combining multiple remote sensing data streams into crop model assimilation schemes to build up Digital Twins of agroecosystems, which may provide the most efficient way to detect the diversity of environmental and biotic stresses and thus enable respective management decisions.

4.
Int J Mol Sci ; 23(3)2022 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-35163729

RESUMO

The synuclein family consists of α-, ß-, and γ-Synuclein (α-Syn, ß-Syn, and γ-Syn) expressed in the neurons and concentrated in synaptic terminals. While α-Syn is at the center of interest due to its implication in the pathogenesis of Parkinson's disease (PD) and other synucleinopathies, limited information exists on the other members. The current study aimed at investigating the biological role of γ-Syn controlling the midbrain dopamine (DA) function. We generated two different mouse models with: (i) γ-Syn overexpression induced by an adeno-associated viral vector and (ii) γ-Syn knockdown induced by a ligand-conjugated antisense oligonucleotide, in order to modify the endogenous γ-Syn transcription levels in midbrain DA neurons. The progressive overexpression of γ-Syn decreased DA neurotransmission in the nigrostriatal and mesocortical pathways. In parallel, mice evoked motor deficits in the rotarod and impaired cognitive performance as assessed by novel object recognition, passive avoidance, and Morris water maze tests. Conversely, acute γ-Syn knockdown selectively in DA neurons facilitated forebrain DA neurotransmission. Importantly, modifications in γ-Syn expression did not induce the loss of DA neurons or changes in α-Syn expression. Collectively, our data strongly suggest that DA release/re-uptake processes in the nigrostriatal and mesocortical pathways are partially dependent on substantia nigra pars compacta /ventral tegmental area (SNc/VTA) γ-Syn transcription levels, and are linked to modulation of DA transporter function, similar to α-Syn.


Assuntos
Dopamina , Neurônios Dopaminérgicos , gama-Sinucleína , Animais , Dopamina/metabolismo , Neurônios Dopaminérgicos/metabolismo , Camundongos , Substância Negra/metabolismo , Transmissão Sináptica/genética , alfa-Sinucleína/genética , alfa-Sinucleína/metabolismo , gama-Sinucleína/genética , gama-Sinucleína/metabolismo
5.
Rev Argent Microbiol ; 54(1): 31-34, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-33838970

RESUMO

Human parechovirus (HPeV) is one of the members of the family Picornaviridae that has been associated with fever of unknown origin, gastroenteritis, clinical sepsis, meningitis, or encephalitis in very young infants. HPeV detection is not routinely performed in most clinical microbiology laboratories in Argentina and, therefore, its real prevalence is unknown. We here report three cases of HPeV CNS infection that presented to our hospital with different clinical features after the implementation of a multiplex PCR meningitis/encephalitis panel. Molecular diagnostic techniques could help improve patient care and understand the real prevalence of this infection in Argentina.


Assuntos
Parechovirus , Infecções por Picornaviridae , Sepse , Argentina , Criança , Humanos , Lactente , Técnicas de Diagnóstico Molecular , Parechovirus/genética , Infecções por Picornaviridae/diagnóstico , Infecções por Picornaviridae/epidemiologia , Sepse/diagnóstico , Sepse/epidemiologia
6.
Int J Mol Sci ; 22(16)2021 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-34445375

RESUMO

Fast and sustained antidepressant effects of ketamine identified the mammalian target of rapamycin (mTOR) signaling pathway as the main modulator of its antidepressive effects. Thus, mTOR signaling has become integral for the preclinical evaluation of novel compounds to treat depression. However, causality between mTOR and depression has yet to be determined. To address this, we knocked down mTOR expression in mice using an acute intracerebral infusion of small interfering RNAs (siRNA) in the infralimbic (IL) or prelimbic (PrL) cortices of the medial prefrontal cortex (mPFC), and evaluated depressive- and anxious-like behaviors. mTOR knockdown in IL, but not PrL, cortex produced a robust depressive-like phenotype in mice, as assessed in the forced swimming test (FST) and the tail suspension test (TST). This phenotype was associated with significant reductions of mTOR mRNA and protein levels 48 h post-infusion. In parallel, decreased brain-derived neurotrophic factor (BDNF) expression was found bilaterally in both IL and PrL cortices along with a dysregulation of serotonin (5-HT) and glutamate (Glu) release in the dorsal raphe nucleus (DRN). Overall, our results demonstrate causality between mTOR expression in the IL cortex and depressive-like behaviors, but not in anxiety.


Assuntos
Depressão/psicologia , Córtex Pré-Frontal/metabolismo , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo , Animais , Fator Neurotrófico Derivado do Encéfalo/genética , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Depressão/genética , Depressão/metabolismo , Modelos Animais de Doenças , Núcleo Dorsal da Rafe/metabolismo , Técnicas de Silenciamento de Genes , Ácido Glutâmico/metabolismo , Elevação dos Membros Posteriores , Masculino , Camundongos , Serotonina/metabolismo , Natação
7.
Int J Mol Sci ; 22(6)2021 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-33805843

RESUMO

α-Synuclein (α-Syn) protein is involved in the pathogenesis of Parkinson's disease (PD). Point mutations and multiplications of the α-Syn, which encodes the SNCA gene, are correlated with early-onset PD, therefore the reduction in a-Syn synthesis could be a potential therapy for PD if delivered to the key affected neurons. Several experimental strategies for PD have been developed in recent years using oligonucleotide therapeutics. However, some of them have failed or even caused neuronal toxicity. One limiting step in the success of oligonucleotide-based therapeutics is their delivery to the brain compartment, and once there, to selected neuronal populations. Previously, we developed an indatraline-conjugated antisense oligonucleotide (IND-1233-ASO), that selectively reduces α-Syn synthesis in midbrain monoamine neurons of mice, and nonhuman primates. Here, we extended these observations using a transgenic male mouse strain carrying both A30P and A53T mutant human α-Syn (A30P*A53T*α-Syn). We found that A30P*A53T*α-Syn mice at 4-5 months of age showed 3.5-fold increases in human α-Syn expression in dopamine (DA) and norepinephrine (NE) neurons of the substantia nigra pars compacta (SNc) and locus coeruleus (LC), respectively, compared with mouse α-Syn levels. In parallel, transgenic mice exhibited altered nigrostriatal DA neurotransmission, motor alterations, and an anxiety-like phenotype. Intracerebroventricular IND-1233-ASO administration (100 µg/day, 28 days) prevented the α-Syn synthesis and accumulation in the SNc and LC, and recovered DA neurotransmission, although it did not reverse the behavioral phenotype. Therefore, the present therapeutic strategy based on a conjugated ASO could be used for the selective inhibition of α-Syn expression in PD-vulnerable monoamine neurons, showing the benefit of the optimization of ASO molecules as a disease modifying therapy for PD and related α-synucleinopathies.


Assuntos
Glicoconjugados/genética , Oligonucleotídeos Antissenso/administração & dosagem , Doença de Parkinson/terapia , Mutação Puntual , alfa-Sinucleína/antagonistas & inibidores , alfa-Sinucleína/genética , Substituição de Aminoácidos , Animais , Corpo Estriado/metabolismo , Corpo Estriado/patologia , Modelos Animais de Doenças , Dopamina/metabolismo , Neurônios Dopaminérgicos/metabolismo , Neurônios Dopaminérgicos/patologia , Glicoconjugados/administração & dosagem , Glicoconjugados/metabolismo , Humanos , Indanos/administração & dosagem , Indanos/química , Indanos/metabolismo , Injeções Intraventriculares , Locus Cerúleo/metabolismo , Locus Cerúleo/patologia , Masculino , Mesencéfalo/metabolismo , Mesencéfalo/patologia , Metilaminas/administração & dosagem , Metilaminas/química , Metilaminas/metabolismo , Camundongos , Camundongos Transgênicos , Norepinefrina/metabolismo , Oligonucleotídeos Antissenso/genética , Oligonucleotídeos Antissenso/metabolismo , Doença de Parkinson/genética , Doença de Parkinson/metabolismo , Doença de Parkinson/patologia , Parte Compacta da Substância Negra/metabolismo , Parte Compacta da Substância Negra/patologia , Transmissão Sináptica , alfa-Sinucleína/metabolismo
8.
Rev Gastroenterol Peru ; 40(1): 73-76, 2020.
Artigo em Espanhol | MEDLINE | ID: mdl-32369470

RESUMO

The glycogen storage diseases contain a range of diseases that are characterized by the abnormal storage or utilization of glycogen, the organs most affected being muscle and / or liver. Hepatomegaly may be a clinical sign that could guide to the diagnosis. We describe a 15-year-old patient with hepatomegaly, hypertransaminasemia and growth retardation. He was diagnosed with a glycogen storage disease by liver biopsy.


Assuntos
Doença de Depósito de Glicogênio/diagnóstico , Hepatopatias/diagnóstico , Adolescente , Doença de Depósito de Glicogênio/fisiopatologia , Hepatomegalia/diagnóstico , Hepatomegalia/etiologia , Humanos , Hepatopatias/fisiopatologia , Masculino
10.
Emerg Infect Dis ; 24(5): 935-937, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29664378

RESUMO

We report identification of an Oropouche virus strain in a febrile patient from Ecuador by using metagenomic sequencing and real-time reverse transcription PCR. Virus was isolated from patient serum by using Vero cells. Phylogenetic analysis of the whole-genome sequence showed the virus to be similar to a strain from Peru.


Assuntos
Infecções por Bunyaviridae/virologia , Orthobunyavirus/isolamento & purificação , Adulto , Animais , Infecções por Bunyaviridae/epidemiologia , Chlorocebus aethiops , Equador/epidemiologia , Humanos , Masculino , Orthobunyavirus/genética , Filogenia , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Células Vero
12.
Langmuir ; 31(33): 8961-79, 2015 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-25805058

RESUMO

Two important and unsolved problems in the food industry and also fundamental questions in colloid chemistry are how to measure molecular distributions, especially antioxidants (AOs), and how to model chemical reactivity, including AO efficiency in opaque emulsions. The key to understanding reactivity in organized surfactant media is that reaction mechanisms are consistent with a discrete structures-separate continuous regions duality. Aggregate structures in emulsions are determined by highly cooperative but weak organizing forces that allow reactants to diffuse at rates approaching their diffusion-controlled limit. Reactant distributions for slow thermal bimolecular reactions are in dynamic equilibrium, and their distributions are proportional to their relative solubilities in the oil, interfacial, and aqueous regions. Our chemical kinetic method is grounded in thermodynamics and combines a pseudophase model with methods for monitoring the reactions of AOs with a hydrophobic arenediazonium ion probe in opaque emulsions. We introduce (a) the logic and basic assumptions of the pseudophase model used to define the distributions of AOs among the oil, interfacial, and aqueous regions in microemulsions and emulsions and (b) the dye derivatization and linear sweep voltammetry methods for monitoring the rates of reaction in opaque emulsions. Our results show that this approach provides a unique, versatile, and robust method for obtaining quantitative estimates of AO partition coefficients or partition constants and distributions and interfacial rate constants in emulsions. The examples provided illustrate the effects of various emulsion properties on AO distributions such as oil hydrophobicity, emulsifier structure and HLB, temperature, droplet size, surfactant charge, and acidity on reactant distributions. Finally, we show that the chemical kinetic method provides a natural explanation for the cut-off effect, a maximum followed by a sharp reduction in AO efficiency with increasing alkyl chain length of a particular AO. We conclude with perspectives and prospects.

13.
Org Biomol Chem ; 13(3): 876-85, 2015 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-25408193

RESUMO

Knowledge on the driving force for the hydrophobic effect that partitions antioxidants (AOs) between the oil (O), aqueous (W) and interfacial (I) regions of food emulsions is crucial to predict their efficiency in inhibiting lipid oxidation and to preserve the organoleptic properties of lipid-based foods. Here, we have investigated the effects of temperature and surfactant volume fraction (ΦI) on the distribution of two representative AOs, the water insoluble α-tocopherol (TOC) and the oil insoluble caffeic acid (CA), in a model food emulsion composed of stripped corn oil, acidic water and the nonionic surfactant Tween 20. The distribution of the AOs is assessed in the intact emulsions by employing a well-established kinetic method based on the reaction between a hydrophobic arenediazonium ion and the AOs. The variations of the observed rate constant, kobs, with ΦI are interpreted on the grounds of the pseudophase kinetic model, which provides values for the interfacial rate constant kI and the partition constants between the aqueous-interfacial (P) and oil-interfacial (P) regions of the emulsions. From the variations of P, P and kI at a series of temperatures, we determined the Gibbs free energy, enthalpy and entropy values for the transfer of CA from the water to the interfacial (W → I) region and of TOC from the oil to the interfacial (O → I) regions of the emulsions, and the activation parameters for the reaction in the interfacial region. Activation energy values are in line with those expected for a bimolecular reaction. Results show that the W → I and O → I transfer processes are spontaneous and entropy driven.


Assuntos
Antioxidantes/química , Ácidos Cafeicos/química , alfa-Tocoferol/química , Óleo de Milho/química , Emulsões , Interações Hidrofóbicas e Hidrofílicas , Cinética , Polissorbatos/química , Propriedades de Superfície , Tensoativos/química , Temperatura , Termodinâmica , Água/química
14.
Pediatr Diabetes ; 15(1): 67-72, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23914949

RESUMO

Recently, bi-allelic mutations in the transcription factor RFX6 were described as the cause of a rare condition characterized by neonatal diabetes with pancreatic and biliary hypoplasia and duodenal/jejunal atresia. A male infant developed severe hyperglycemia (446 mg/dL) within 24 h of birth. Acute abdominal concerns by day five necessitated exploratory surgery that revealed duodenal atresia, gallbladder agenesis, annular pancreas and intestinal malrotation. He also exhibited chronic diarrhea and feeding intolerance, cholestatic jaundice, and subsequent liver failure. He died of sepsis at four months old while awaiting liver transplantation. The phenotype of neonatal diabetes with intestinal atresia and biliary agenesis clearly pointed to RFX6 as the causative gene; indeed, whole exome sequencing revealed a novel homozygous RFX6 mutation c.779A>C; p.Lys260Thr (K260T). This missense mutation also changes the consensus 5' splice donor site before intron 7 and is thus predicted to cause disruption in splicing. Both parents, who were not known to be related, were heterozygous carriers. Targeted genetic testing based on consideration of phenotypic features may reveal a cause among the many genes now associated with heterogeneous forms of monogenic neonatal diabetes. Our study demonstrates the feasibility of using modern sequencing technology to identify one such rare cause. Continued research is needed to determine the possible cost-effectiveness of this approach, especially when clear phenotypic clues are absent. Further study of patients with RFX6 mutations should clarify its role in pancreatic, intestinal and enteroendocrine cellular development and explain features such as the diarrhea exhibited in our case.


Assuntos
Anormalidades Múltiplas/genética , Proteínas de Ligação a DNA/genética , Diabetes Mellitus Tipo 1/congênito , Doenças do Recém-Nascido/genética , Fatores de Transcrição/genética , Anormalidades Congênitas , Anormalidades do Sistema Digestório , Obstrução Duodenal , Evolução Fatal , Vesícula Biliar/anormalidades , Humanos , Lactente , Recém-Nascido , Atresia Intestinal , Volvo Intestinal , Masculino , Pâncreas/anormalidades , Pancreatopatias , Fatores de Transcrição de Fator Regulador X
15.
Pediatr Diabetes ; 15(3): 252-6, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24138066

RESUMO

Neonatal diabetes mellitus is known to have over 20 different monogenic causes. A syndrome of permanent neonatal diabetes along with primary microcephaly with simplified gyral pattern associated with severe infantile epileptic encephalopathy was recently described in two independent reports in which disease-causing homozygous mutations were identified in the immediate early response-3 interacting protein-1 (IER3IP1) gene. We report here an affected male born to a non-consanguineous couple who was noted to have insulin-requiring permanent neonatal diabetes, microcephaly, and generalized seizures. He was also found to have cortical blindness, severe developmental delay and numerous dysmorphic features. He experienced a slow improvement but not abrogation of seizure frequency and severity on numerous anti-epileptic agents. His clinical course was further complicated by recurrent respiratory tract infections and he died at 8 years of age. Whole exome sequencing was performed on DNA from the proband and parents. He was found to be a compound heterozygote with two different mutations in IER3IP1: p.Val21Gly (V21G) and a novel frameshift mutation p.Phe27fsSer*25. IER3IP1 is a highly conserved protein with marked expression in the cerebral cortex and in beta cells. This is the first reported case of compound heterozygous mutations within IER3IP1 resulting in neonatal diabetes. The triad of microcephaly, generalized seizures, and permanent neonatal diabetes should prompt screening for mutations in IER3IP1. As mutations in genes such as NEUROD1 and PTF1A could cause a similar phenotype, next-generation sequencing approaches-such as exome sequencing reported here-may be an efficient means of uncovering a diagnosis in future cases.


Assuntos
Proteínas de Transporte/genética , Diabetes Mellitus/genética , Epilepsia Generalizada/etiologia , Mutação da Fase de Leitura , Doenças do Recém-Nascido/genética , Proteínas de Membrana/genética , Microcefalia/etiologia , Mutação Puntual , Substituição de Aminoácidos , Cegueira Cortical/etiologia , Deficiências do Desenvolvimento/etiologia , Diabetes Mellitus/fisiopatologia , Diabetes Mellitus/terapia , Epilepsia Generalizada/fisiopatologia , Epilepsia Generalizada/terapia , Evolução Fatal , Heterozigoto , Humanos , Recém-Nascido , Doenças do Recém-Nascido/fisiopatologia , Masculino , Microcefalia/fisiopatologia , Microcefalia/terapia , Manifestações Neurológicas , Índice de Gravidade de Doença
16.
Artigo em Inglês | MEDLINE | ID: mdl-38992345

RESUMO

Neuropsychiatric and neurodegenerative disorders are frequently associated with gastrointestinal (GI) co-pathologies. Although the central and enteric nervous systems (CNS and ENS, respectively) have been studied separately, there is increasing interest in factors that may contribute to conditions affecting both systems. There is compelling evidence that serotonin (5-HT) may play an important role in several gut-brain disorders. It is well known that 5-HT is essential for the development and functioning of the CNS. However, most of the body's 5-HT is produced in the GI tract. A deeper understanding of the specific effects of enteric 5-HT on gut-brain disorders may provide the basis for the development of new therapeutic targets. This review summarizes current data focusing on the important role of 5-HT in ENS development and motility, with particular emphasis on novel aspects of 5-HT signaling in conditions where CNS and ENS comorbidities are common, such as Parkinson's disease and depressive disorders.

17.
iScience ; 27(5): 109787, 2024 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-38711453

RESUMO

Depression is a devastating mood disorder that causes significant disability worldwide. Current knowledge of its pathophysiology remains modest and clear biological markers are lacking. Emerging evidence from human and animal models reveals persistent alterations in endoplasmic reticulum (ER) homeostasis, suggesting that ER stress-related signaling pathways may be targets for prevention and treatment. However, the neurobiological basis linking the pathways involved in depression-related ER stress remains unknown. Here, we report that an induced model of ER stress in mouse serotonin (5-HT) neurons is associated with reduced Egr1-dependent 5-HT cellular activity and 5-HT neurotransmission, resulting in neuroplasticity deficits in forebrain regions and a depressive-like phenotype. Ketamine administration engages downstream eIF2α signaling to trigger rapid neuroplasticity events that rescue the depressive-like effects. Collectively, these data identify ER stress in 5-HT neurons as a cellular pathway involved in the pathophysiology of depression and show that eIF2α is critical in eliciting ketamine's fast antidepressant effects.

18.
Eur J Pharmacol ; 953: 175802, 2023 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-37295763

RESUMO

Antipsychotic drugs of different chemical/pharmacological families show preferential dopamine (DA) D2 receptor (D2-R) vs. D1 receptor (D1-R) affinity, with the exception of clozapine, the gold standard of schizophrenia treatment, which shows a comparable affinity for both DA receptors. Here, we examined the ability of Lu AF35700 (preferential D1-R>D2-R antagonist), to reverse the alterations in thalamo-cortical activity induced by phencyclidine (PCP), used as a pharmacological model of schizophrenia. Lu AF35700 reversed the PCP-induced alteration of neuronal discharge and low frequency oscillation (LFO, 0.15-4 Hz) in thalamo-cortical networks. Likewise, Lu AF35700 prevented the increased c-fos mRNA expression induced by PCP in thalamo-cortical regions of awake rats. We next examined the contribution of D1-R and D2-R to the antipsychotic reversal of PCP effects. The D2-R antagonist haloperidol reversed PCP effects on thalamic discharge rate and LFO. Remarkably, the combination of sub-effective doses of haloperidol and SCH-23390 (DA D1-R antagonist) fully reversed the PCP-induced fall in thalamo-cortical LFO. However, unlike with haloperidol, SCH-23390 elicited different degrees of potentiation of the effects of low clozapine and Lu AF35700 doses. Overall, the present data support a synergistic interaction between both DA receptors to reverse the PCP-induced alterations of oscillatory activity in thalamo-cortical networks, possibly due to their simultaneous blockade in direct and indirect pathways of basal ganglia. The mild potentiation induced by SCH-23390 in the case of clozapine and Lu AF35700 suggests that, at effective doses, these agents reverse PCP effects through the simultaneous blockade of both DA receptors.


Assuntos
Antipsicóticos , Clozapina , Ratos , Animais , Fenciclidina/farmacologia , Clozapina/farmacologia , Haloperidol/farmacologia , Dopamina , Antipsicóticos/farmacologia , Antagonistas de Dopamina/farmacologia , Receptores de Dopamina D1
19.
Artigo em Inglês | MEDLINE | ID: mdl-35840289

RESUMO

OBJECTIVE: Recently, we reported on a new MDD-like mouse model based on a regionally selective knockdown of astroglial glutamate transporters, GLAST/GLT-1, in infralimbic cortex (IL) which evokes widespread changes in mouse brain associated with the typical alterations found in MDD patients. To further characterize this new MDD-like mouse model, here we examine some transcriptional elements of glutamatergic/GABAergic neurotransmission and neuroplasticity in forebrain regions in the GLT-1 knockdown mice. Furthermore, we assess the acute ketamine effects on these transcriptional processes. MATERIAL AND METHODS: We used a small interfering RNA (siRNA) pool targeting GLT-1 mRNA to disrupt the GLT-1 transcription in mouse IL. Histological assays were performed to examine postsynaptic density protein-95 (PSD95), neuritin (NRN), glutamine acid descarboxilase-65 (GAD65), and GLT-1 mRNA expression in IL and hippocampus. RESULTS: Knockdown of GLT-1 in mouse IL leads to decreased expression of PSD95 and NRN neuroplasticity mRNAs in IL and hippocampus, which was reversed by an acute dose of ketamine antidepressant. Likewise, a single dose of ketamine also increased the mRNA levels of GAD65 and GLT-1 in IL of GLT-1 knockdown mice, reaching the basal values of control mice. CONCLUSIONS: The glutamatergic neuronal hyperactivity and deficits in the GABA system resulting from siRNA-induced astroglial glutamate transporter knockdown in IL can compromise the integrity/plasticity of neurocircuits affected in MDD. Suitable depressive-like animal models to address the neurobiological changes in MDD are an unmet need and the development of the GLAST/GLT-1 knockdown mouse model may represent a better option to understand the rapid-acting antidepressant effects of ketamine.


Assuntos
Astrócitos , Ketamina , Plasticidade Neuronal , Sistema X-AG de Transporte de Aminoácidos/metabolismo , Animais , Antidepressivos/farmacologia , Antidepressivos/uso terapêutico , Astrócitos/metabolismo , Depressão/genética , Depressão/metabolismo , Transportador 2 de Aminoácido Excitatório/efeitos dos fármacos , Transportador 2 de Aminoácido Excitatório/genética , Humanos , Ketamina/metabolismo , Ketamina/farmacologia , Ketamina/uso terapêutico , Camundongos , Plasticidade Neuronal/efeitos dos fármacos , Plasticidade Neuronal/genética , RNA Mensageiro/metabolismo , RNA Interferente Pequeno/metabolismo
20.
Arch Argent Pediatr ; 120(5): 336-339, 2022 10.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-36190218

RESUMO

Stopping the spread of coronavirus disease 2019 (COVID-19) is critical and can be achieved through rapid and effective detection techniques. Our objective was to compare the diagnostic accuracy of rapid antigen tests (RAgT) and reverse transcriptionquantitative polymerase chain reaction (RT-qPCR) and to describe amplification cycle thresholds (Cts). Participants were children aged 1 month to 11 years with symptoms for less than 7 days, who did not have a detectable result in the past 90 days, and were immunocompetent. A total of 1855 patients were included; the prevalence of COVID-19 was 4.7%. For the RAgT, overall sensitivity was 60.2% and specificity, 99.8%; in children older than 5 years, values were 69.8% and 99.8%, respectively. Ct values for discordant samples were higher. To conclude, the diagnostic accuracy indicated that the specificity of RAgT is similar to that of RT-qPCR, but its sensitivity is notably lower, especially in children younger than 5 years.


Frenar la propagación de la enfermedad por el coronavirus 2019 (COVID-19, por su sigla en inglés) es fundamental, y se puede realizar mediante técnicas de detección rápidas y efectivas. El objetivo fue comparar la precisión diagnóstica de un test rápido de antígeno (TRAg,) con la reacción en cadena de polimerasa con retrotranscripción (RT-qPCR, por su sigla en inglés) y describir los umbrales de amplificación (Ct, por su sigla en inglés). Participaron niños de 1 mes a 11 años que tuvieran menos de 7 días de síntomas, sin resultado detectable en los últimos 90 días, e inmunocompetentes. Se incluyeron 1855 pacientes con una prevalencia de COVID-19 del 4,7 %. La sensibilidad global del TRAg fue del 60,2 % y su especificidad, del 99,8 %; en niños mayores de 5 años los valores fueron de 69,8 % y 99,8 %, respectivamente. Los valores de Ct de las muestras discordantes fueron más altos. En conclusión, la precisión diagnóstica muestra que TRAg tiene una especificidad similar a la RT-qPCR, pero una sensibilidad considerablemente menor, sobre todo en niños de menos de 5 años.


Assuntos
COVID-19 , SARS-CoV-2 , COVID-19/diagnóstico , Teste para COVID-19 , Criança , Pré-Escolar , Técnicas de Laboratório Clínico/métodos , Humanos , Reação em Cadeia da Polimerase em Tempo Real , Sensibilidade e Especificidade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA