Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Mais filtros

Base de dados
Intervalo de ano de publicação
Artigo em Inglês | MEDLINE | ID: mdl-32800866


Methylphenidate (MPH) is a psychostimulant widely misused to increase wakefulness by drivers and students. Also, MPH can be found in dietary supplements in a clandestine manner aiming to burst performance of physical exercise practitioners. The abusive use of high doses of caffeine (CAF) in these contexts is equally already known. Here, we demonstrate the behavioral, oxidative and mitochondrial effects after acute exposure to high doses of MPH (80 mg/L) and CAF (150 mg/L), alone or associated (80 mg/L + 150 mg/L, respectively). We used zebrafish as animal model due to its high translational relevance. We evaluated the behavioral effects using the Novel Tank Test (NTT), Social Preference Test (SPT) and Y-maze Task and analyzed biomarkers of oxidative stress and activity of mitochondrial respiratory chain complexes. MPH alone induced antisocial behavior. MPH inhibited lipid peroxidation. The association of MPH + CAF presented memory impairment and anxiogenic behavior. In oxidative status, it inhibited lipid peroxidation, increased protein carbonylation and mitochondrial complex II, III and IV activity. Our results demonstrate that MPH and CAF alone negatively impact the typical behavioral of zebrafish. When associated, changes in cognition, memory, oxidative and mitochondrial status are more relevant.

Environ Toxicol Pharmacol ; 80: 103473, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32860936


Residual contamination of water with MPH represents a severe environmental issue because it can affect non-target animals. Here we describe the behavioral effects in zebrafish after chronic contamination of water containing residues of MPH (0.1875, 1.875 and 3 ug/L). These doses are environmentally relevant since they reflect those found in wastewaters. We evaluated the behavioral effect through the novel tank test (NTT) and social preference test (SPT), and after euthanasia we analyzed oxidative stress parameters. Zebrafish exposed to MPH presented a social impairment, avoiding the conspecifics segment in the social preference test. In addition, MPH in the lowest concentration provoked an anxiolytic effect in the novel tank test. Oxidative stress is not related to these changes. Since the maintenance of an intact behavioral repertoire is crucial for species survival and fitness, our results demonstrate that residual contamination of water by MPH can be a threat to zebrafish, impacting directly to its well-being and survival in the aquatic environment.

Physiol Behav ; 222: 112944, 2020 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-32407833


Zebrafish has become an animal model in research and articles have established ideal conditions for their maintenance. However, little is known regarding the influence of gender and other cues on zebrafish behavior. Thus, here we analyzed the exploratory and social behavior of different sexes (male and female, mixed or segregated) under different housing conditions with various types of stimuli (visual or/and chemical cues and structural environmental enrichment). Segregated females and males were more active than mixed individuals and females were more anxious. Fish that visualized and smelled the opposite sex presented higher activity and were less anxious than individuals that only smelled or visualized the opposite sex. Fish segregated by sex while being allowed to visualize and smell the opposite sex with the presence of structural environmental enrichment exhibited lower activity and anxiety-like behavior than fish without structural environmental enrichment. Thus, we emphasized that these variables should be taken into account in housing conditions and should be detailed for better replicability and reproducibility of experiments performed with zebrafish.

Stress ; : 1-6, 2020 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-32013653


We report the effects of acute and chronic stress on the expression of selective immune-related genes and markers of neuronal function in the brain of the zebrafish (Danio rerio). Fish were distributed into three groups: the non-stressed control group; the acute stress (AS) group, submitted to a single stressing episode; and the unpredictable chronic stress (UCS) group, submitted to two daily stressing episodes of alternating times and types of stress. The stressing protocols were applied for a period of 14 days. The UCS protocol triggered the expression of the pro-inflammatory cytokine genes IL-1ß and TNF-α, the anti-inflammatory cytokine IL-10 (negative feedback from the immune system), reduction in cFOS gene expression, and caused neuro-inflammation. The AS protocol had no effect on gene expression. Altered expression of cytokine genes, as observed in our study, correlates with several pathologies associated with neuro-inflammation, and the reduction of cFOS gene expression may indicate the occurrence of reduced neuronal plasticity. Our study further extends our knowledge about the interaction of the immune system and the different forms of stress.

Pharmacol Biochem Behav ; 189: 172841, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31893526


Environmental pollution caused by antipsychotic residues is a relevant ecological problem. Studies revealed that residues of these drugs are present in a wide range of different ecosystems and can have adverse effects on non-target organisms even in low environmental concentrations. Among these antipsychotic drugs, aripiprazole (APPZ) is a second-generation atypical antipsychotic that is a partial agonist of dopaminergic and serotoninergic receptors. APPZ is used to treat schizophrenia, bipolar disorder, autism, obsessive-compulsive disorder, and anxiety or panic disorders. Thus, in this study we posed the following question: "What will be the behavioral effects of waterborne APPZ on fish?" To answer this question, we exposed adult zebrafish to different APPZ concentrations (0.556, 5.56, and 556 ng/L) for 15 min and evaluated their exploratory, anxiety-like, social, and anti-predatory behaviors. Our results showed that, despite the apparent beneficial reversal of stress-induced social impairment and anxiety-like behavior, APPZ exposure impaired the anti-predatory reaction of adult zebrafish. Taken altogether, our results show that APPZ-exposed zebrafish may have a decreased perception of predators, even at concentrations lower than those already detected in the environment. A failure to exhibit an antipredatory response may favor the predator, decrease the fitness of the prey species, and, consequently, affect the food chain. Our results highlight the risks and consequences associated with APPZ residues in water, which may affect aquatic life and endanger species that depend on appropriate behavioral responses for survival.