Publications by authors named "Roberto F Almeida"

Major Depressive Disorder (MDD) is a severe and multifactorial psychiatric condition. Evidence has shown that environmental factors, such as stress, significantly explain MDD pathophysiology. Studies have hypothesized that changes in histone methylation patterns are involved in impaired glutamatergic signaling.

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Data recently reported by our group indicate that stimulation with a pool of immunogens capable of eliciting type 2 immune responses can restore the cognitive and behavioral dysfunctions recorded after a single episode of non-severe rodent malaria caused by ANKA. Here we explored the hypothesis that isolated immunization with one of the type 2 immune response-inducing immunogens, the human diphtheria-tetanus (dT) vaccine, may revert damages associated with malaria. To investigate this possibility, we studied the dynamics of cognitive deficits and anxiety-like phenotype following non-severe experimental malaria and evaluated the effects of immunization with both dT and of a pool of type 2 immune stimuli in reversing these impairments.

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Pyrrolizidine alkaloids (PAs) are secondary plant metabolites playing an important role as phytotoxins in the plant defense mechanisms and can be present as contaminant in the food of humans and animals. The PA monocrotaline (MCT), one of the major plant derived toxin that affect humans and animals, is present in a high concentration in Crotalaria spp. (Leguminosae) seeds and can induce toxicity after consumption, characterized mainly by hepatotoxicity and pneumotoxicity.

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Background: Autism spectrum disorder (ASD) is a neurodevelopmental condition associated with severe social communication, interaction, and sensory processing impairments. Efforts to understand its etiology and pathophysiology are crucial for improving treatment and prevention measures. Preclinical models of ASD are essential for investigating the biological mechanisms and should present translatability potential.

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Background: The effects of tobacco smoke on the central nervous system are usually studied with isolated nicotine, ignoring other compounds present in cigarette smoke. The few studies that use in vivo whole-body cigarette smoke exposure are usually performed in expensive commercial apparatus.

New Method: We presented a feasible, safe, and low-cost apparatus for cigarette smoke exposure in rodents.

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Glutamate removal from the extracellular space by high-affinity Na-dependent transporters is essential to ensure that the brain's intrinsic connectivity mechanisms work properly and homeostasis is maintained. The hippocampus is a unique brain structure that manages higher cognitive functions, and is the subject of several studies regarding neurologic diseases. The investigation of physiological and pathological mechanisms in rodent models can benefit from acute hippocampal slice (AHS) preparations.

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Major depressive disorder (MDD) leads to pervasive changes in the health of afflicted patients. Despite advances in the understanding of MDD and its treatment, profound innovation is needed to develop fast-onset antidepressants with higher effectiveness. When acutely administered, the endogenous nucleoside guanosine (GUO) shows fast-onset antidepressant-like effects in several mouse models, including the olfactory bulbectomy (OBX) rodent model.

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The immune system plays a role in the maintenance of healthy neurocognitive function. Different patterns of immune response triggered by distinct stimuli may affect nervous functions through regulatory or deregulatory signals, depending on the properties of the exogenous immunogens. Here, we investigate the effect of immune stimulation on cognitive-behavioural parameters in healthy mice and its impact on cognitive sequelae resulting from non-severe experimental malaria.

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Early life stressors, such as social isolation (SI), can disrupt brain development contributing to behavioral and neurochemical alterations in adulthood. Purinergic receptors and ectonucleotidases are key regulators of brain development in embryonic and postnatal periods, and they are involved in several psychiatric disorders, including schizophrenia. The extracellular ATP drives purinergic signaling by activating P2X and P2Y receptors and it is hydrolyzed by ectonucleotidases in adenosine, which activates P1 receptors.

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Ischemic stroke is a major cause of morbidity and mortality worldwide and only few affected patients are able to receive treatment, especially in developing countries. Detailed pathophysiology of brain ischemia has been extensively studied in order to discover new treatments with a broad therapeutic window and that are accessible to patients worldwide. The nucleoside guanosine (Guo) has been shown to have neuroprotective effects in animal models of brain diseases, including ischemic stroke.

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Methylmercury (MeHg) is known to be a chemical that poses a risk to public health. Exposure to MeHg and vitamin A (VitA) occurs through the ingestion of fish, present in the diet of most pregnant women. The absorption of these elements generates oxidative stress and can generate adaptations for future stressful events.

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Obesity is a health problem that has been associated with neuroinflammation, decreased cognitive functions and development of neurodegenerative diseases. Parkinson's disease (PD) is a chronic neurodegenerative condition characterized by motor and non-motor abnormalities, increased brain inflammation, -synuclein protein aggregation and dopaminergic neuron loss that is associated with decreased levels of tyrosine hydroxylase (TH) in the brain. Diet-induced obesity is a global epidemic and its role as a risk factor for PD is not clear.

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Taurine is an amino acid usually added to energy drinks. In rodents, acute taurine administration decreases voluntary alcohol intake, and subchronic administration restores different behavioral features impaired by alcohol withdrawal. In the present study, we evaluated the effects of chronic taurine treatment on voluntary alcohol consumption and changes in behavioral parameters in rats.

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The treatment of major depressive disorder (MDD) is still a challenge. In the search for novel antidepressants, glutamatergic neuromodulators have been investigated as possible fast-acting antidepressants. Innovative studies suggest that the purine cycle and/or the purinergic signaling can be dysregulated in MDD, and the endogenous nucleoside guanosine has gained attention due to its extracellular effects.

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Objective: Exposure to artificial sweeteners, such as aspartame, during childhood and adolescence has been increasing in recent years. However, the safe use of aspartame has been questioned owing to its potentially harmful effects on the developing brain. The aim of this study was to test whether the chronic consumption of aspartame during adolescence leads to a depressive-like phenotype and to investigate the possible mechanisms underlying these behavioral changes.

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Interactions on neurotransmitter systems in the reward pathways may explain the high frequency of combined use of alcohol and cigarettes in humans. In this study, we evaluated some behavioral and neurochemical changes promoted by chronic exposure to alcohol and cigarette smoke in rats. Adult rats were administered with 2 g/kg alcohol (v.

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Methylmercury (MeHg) is an organic bioaccumulated mercury derivative that strongly affects the environment and represents a public health problem primarily to riparian communities in South America. Our objective was to investigate the hepatic and neurological effects of MeHg exposure during the phases foetal and breast-feeding and adult in Wistar rats. Wistar rats (n = 10) were divided into 3 groups.

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Longitudinal and some experimental studies have showed the potential of caffeine to counteract some depressive behaviors and synaptic dysfunctions. In this study, we investigated the potential of caffeine in preventing behavioral outcomes, neurodegeneration and synaptic proteins alterations in a mice model of agitated depression by bilateral olfactory bulbectomy (OB). For this purpose, bulbectomized mice received caffeine (0.

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Astrocytes are a unique and dynamic subtype of glial cells in the central nervous system (CNS). Understanding their biochemical reactions and their influence in the surrounding cells is extremely important in the neuroscience field. They exert important influence in the neurotransmission, ionic homeostasis and also release neuroactive molecules termed gliotransmitters.

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Carvacrol (CARV) presents valuable biological properties such as anti-inflammatory and antioxidant activities. However, pharmacological uses of CARV are largely limited due to disadvantages related to solubility, bioavailability, preparation and storage processes. The complexation of monoterpenes with β-cyclodextrin (β-CD) increases their stability, solubility and oral bioavailability.

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Autism spectrum disorder (ASD) refers to a group of heterogeneous brain-based neurodevelopmental disorders with different levels of symptom severity. Given the challenges, the clinical diagnosis of ASD is based on information gained from interviews with patients' parents. The heterogeneous pathogenesis of this disorder appears to be driven by genetic and environmental interactions, which also plays a vital role in predisposing individuals to ASD with different commitment levels.

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Guanosine (GUO) has neuroprotective effects in experimental models of brain diseases involving glutamatergic excitotoxicity in male animals; however, its effects in female animals are poorly understood. Thus, we investigated the influence of gender and GUO treatment in adult male and female Wistar rats submitted to focal permanent cerebral ischemia in the motor cortex brain. Female rats were subdivided into non-estrogenic and estrogenic phase groups by estrous cycle verification.

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Background: Cerebral malaria, the main complication of Plasmodium falciparum infection in humans, is associated with persistent neurocognitive sequels both in human disease and the murine experimental model. In recent years, cognitive deficits related to uncomplicated (non-cerebral) malaria have also been reported in chronically exposed residents of endemic areas, but not in some murine experimental models of non-cerebral malaria. This study aimed at evaluating the influence of uncomplicated malaria on different behavioural paradigms associated with memory and anxiety-like parameters in a murine model that has the ability to develop cerebral malaria.

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