Search

Household insecticide is largely used for insect and ectoparasite control, in city centers as well as in the countryside. The pyrethroids are the most used class of insecticide, these compounds in low doses have low toxicity for mammalians, in comparison to other compounds, with insecticide effects. The contact of these compounds in sublethal doses begins in early life and many cases, in intrauterine life. Considerable diseases still with undefined etiology, such as neurodegenerative conditions, and Huntington's Disease (HD) is one of them. HD is related to overexpression of Polyglutamine (PolyQ40), its aggregation, and non-solubilization, which leads to neural, behavioral, and cognitive damage. In our study, we evaluate the effect of two sublethal doses of a prallethrin-based insecticide (P-BI), in three different Caenorhabditis elegans life stages transgenerational, neonatal, and lifespan. We evaluated the Body bends and pharyngeal pumping rate, and social feeding as behavioral biomarkers. As well as acetylcholinesterase activity (AChE), PolyQ40 aggregation, antioxidant enzymes, and heat shock protein (HSP) expression. We observe that the toxic effect of P-BI is more pronounced on transgenerational and lifespan exposure. Both sublethal doses of P-BI decreased the AChE activity and retard the HSP expression as well as increased the PolyQ40 aggregates indicating a clear biomarker for possible effect in the progression of the HD, by the environmental contamination.

Highly toxic chemical compounds are present in rivers and lakes, endangering the survival of non-target species. To evaluate the effects of environmental contamination on non-target species, we used the zebrafish as an animal model. Environmental concentrations of the widely used pesticides, glyphosate (GBH) at 4.8 μg·L

The dopaminergic system of zebrafish is complex and the numerous pathways and receptors in the central nervous system (CNS) are being extensively studied. A critical factor for the synthesis, activation and release of catecholamines (CAs) is the presence of tyrosine hydroxylase, an enzyme which converts L-tyrosine into levodopa. Levodopa thus is the intermediary in the synthesis of dopamine (DA) and norepinephrine (NE) and promotes its release; therefore, CAs play an important role in the CNS with hormonal functions. Here, we use levodopa/carbidopa to clarify the involvement of the dopaminergic pathway in the stress response in zebrafish submitted to an acute stress challenge. Acute stress was induced by chasing fish with a net for 2 min and assessed by measuring whole-body cortisol levels. Two experiments were carried out, the first with exposure to levodopa/carbidopa and the second with exposure to AMPT and levodopa/carbidopa. Levodopa/carbidopa balances the stress response through its action on the zebrafish hypothalamic–pituitary–adrenal (HPA) axis. Changes in cortisol levels suggest that DA was related to the balance of the stress response and that NE decreased this response. These effects were specific to stress since levodopa/carbidopa did not induce changes in cortisol in non-stressed fish.

The harmful effects of heavy metals on organisms have not been fully described. At present, there is a close relationship between neurodegenerative diseases and copper toxicity. In addition, the copper effect on the central nervous system is followed by high levels of free radicals in different body tissues. An increase in free radical levels leads to aging-related diseases, resulting in the appearance of senile comorbidities. An increase in the consumption of natural compounds that could help to reduce this dangerous effect on organisms was observed. Pitaya (Hylocereus undatus) is a tropical fruit with great antioxidant potential and can help the organism with oxidative damage. This study evaluated the effect of H. undatus on zebrafish organisms in front of copper-induced toxicity. Therefore, the behavior, cholinergic system, antioxidant enzymes, and ALAD activity were evaluated as biomarkers. Our results highlight the great potential of Pitaya's pulp to reduce the levels of anxiety and aggressivity in fish and reduce cortisol levels. It could mediate the normal response of the cholinergic nervous system, antioxidant enzymes, and ALAD activity. Therefore, our data suggest that pitaya might improve the senile aging. PRACTICAL APPLICATIONS: The potential practical application of this study is related to the neuroprotective effect of the Hylocereus undatus microencapsulated pulp extract against metal-induced impairments. The results have shown that this extract is able to reduce the copper-induced damage modulating the antioxidant system and the cholinergic nervous system. One of the implicated potentials of use for this extract is the food supplementation to its fortification.

Pesticides reach water bodies through different routes, either owing to incorrect packaging disposal, direct application to control macrophytes, leaching from fields, or natural degradation processes. In the aquatic environment, adverse effects in non-target species that come in contact with these substances are poorly understood. Currently, the most used pesticides are glyphosate (GBH) and 2,4-dichlorophenoxyacetic acid-based herbicides (DBH), as its presence in water bodies is already known, we used environmental concentrations and our exposure time comprised the entire period of organogenesis (3-120 h post-fertilization). We evaluated the response of embryos in their early development with the parameters of mortality, hatching, spontaneous movement, and heart rate; and it's through behavior the open field test and aversive stimulus, as well as biochemical analyzes of acetylcholinesterase activity (AChE), catalase (CTL) and superoxide dismutase (SOD) as a possible mechanism of action. Exposure to GBH decreased survival, caused hypermobility and anxiolytic behavior, negatively affected the anti-predatory behavior of the larvae, and increases acetylcholinesterase activity, whereas exposure to DBH caused only slight hypermobility in the larvae and increases acetylcholinesterase activity. These changes may compromise the perpetuation of the species, the search for partners/food, and facilitate the action of predators, which can result in serious ecological consequences.

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 distrib...

Since behavior is the connection between the internal physiological processes of an animal and its interaction with the environment, a complete behavioral repertoire is crucial for fish survival and fitness, at both the individual and population levels. Thus, unintended exposure of non-target organisms to antipsychotic residues in the environment can impact their normal behavior, and some of these behavioral changes can be seen during the entire life of the animal and passed to subsequent generations. Although there are some reports related to transgenerational toxicology, little is known of the long-term consequences of exposure to pharmaceutical compounds such as risperidone. Here, we show that zebrafish exposed to risperidone (RISP) during embryonic and larval stages presented impaired anti-predatory behavior during adulthood, characterizing a persistent effect. We also show that some of these behavioral changes are present in the following generation, characterizing a transgenerational effect. This suggests that even short exposures to environmentally relevant concentrations, at essential stages of development, can persist throughout the whole life of the zebrafish, including its offspring. From an environmental perspective, our results suggested possible risks and long-term consequences associated with drug residues in water, which can affect aquatic life and endanger species that depend on appropriate behavioral responses for survival.

The consumption of progestins has increased considerably in recent decades, as has their disposal into the environment. These substances can negatively affect the reproduction, physiology, and behavior of non-target organisms, such as fish. We aimed to evaluate the effects of exposure to environmentally relevant concentrations of levonorgestrel-control birth based (1.3, 13.3, 133, and 1330 ng/L) on the development and behavior of zebrafish (Danio rerio) in terms of mortality, hatching, spontaneous movement, and larval and adult behavioral tests. Exposure caused anxiogenic-like behavior in larvae, which persisted in adults, as demonstrated by the light-dark test. In contrast, it caused anxiolytic-like behavior in the novel tank test. There was a high mortality rate at all tested concentrations and increases in the hormone cortisol at 13.3 ng/L that affected the sex ratio. These changes may lead to an ecological imbalance, emphasizing the risk of early exposure to progestins in the environment.

The zebrafish (Danio rerio) is widely used as a promising translational model organism for studying various brain disorders. Zebrafish are also commonly used in behavioral and drug screening assays utilizing individually tested (socially isolated) fish. Various sounds represent important exogenous factors that may affect fish behavior. Mounting evidence shows that musical/auditory environmental enrichment can improve welfare of laboratory animals, including fishes. Here, we show that auditory environmental enrichment mitigates anxiogenic-like effects caused by acute 24-h social isolation in adult zebrafish. Thus, auditory environmental enrichment may offer an inexpensive, feasible and simple tool to improve welfare of zebrafish stocks in laboratory facilities, reduce unwanted procedural stress, lower non-specific behavioral variance and, hence, collectively improve zebrafish data reliability and reproducibility.

Viticulture plays an important role in generating income for small farms globally. Historically, vineyards use large quantities of phytosanitary products, such as Bordeaux mixture [Ca(OH)2 + CuSO4], to control plant diseases. These products result in the accumulation of copper (Cu) in the soil and increases the risk of transfer to water bodies. Thus, it is important to evaluate whether the presence of Cu-bearing particles in water is toxic to aquatic fauna. This study conducted chemical, mineralogical, and particle size evaluations on water samples and sediments collected from a watershed predominantly cultivated with old vineyards. The proportion of Cu-rich nanoparticles (

The zebrafish (Danio rerio) is used as an emergent model organism to investigate the behavioral and physiological responses to stress. The anxiolytic-like effects of taurine in zebrafish support the existence of different mechanisms of action, which can play a role in preventing stress-related disorders (i.e., modulation of GABAA, strychnine-sensitive glycine, and NMDA receptors, as well as antioxidant properties). Herein, we investigate whether taurine modulates some behavioral and biochemical responses in zebrafish acutely submitted to chemical and mechanical stressors. We pretreated zebrafish for 1 h in beakers at 42, 150, and 400 mg/L taurine. Fish were later acutely exposed to a chemical stressor (conspecific alarm substance) or to a mechanical stressor (net chasing), which elicits escaping responses and aversive behaviors. Locomotion, exploration, and defensive-like behaviors were measured using the novel tank and the light–dark tests. Biochemical (brain oxidative stress-related parameters) and whole-body cortisol levels were also quantified. We showed that taurine prevents anxiety/fear-like behaviors and protein carbonylation and dampens the cortisol response following acute stress in zebrafish. In summary, our results demonstrate a protective role of taurine against stress-induced behavioral and biochemical changes, thereby reinforcing the growing utility of zebrafish models to investigate the neuroprotective actions of taurine in vertebrates.

The dopaminergic system of zebrafish is complex and the numerous pathways and receptors in the central nervous system (CNS) are being extensively studied. A critical factor for the synthesis, activation and release of catecholamines (CAs) is the presence of tyrosine hydroxylase, an enzyme which converts L-tyrosine into levodopa. Levodopa thus is the intermediary in the synthesis of dopamine (DA) and norepinephrine (NE) and promotes its release; therefore, CAs play an important role in the CNS with hormonal functions. Here, we use levodopa/carbidopa to clarify the involvement of the dopaminergic pathway in the stress response in zebrafish submitted to an acute stress challenge. Acute stress was induced by chasing fish with a net for 2 min and assessed by measuring whole-body cortisol levels. Two experiments were carried out, the first with exposure to levodopa/carbidopa and the second with exposure to AMPT and levodopa/carbidopa. Levodopa/carbidopa balances the stress response through its action on the zebrafish hypothalamic-pituitary-adrenal (HPA) axis. Changes in cortisol levels suggest that DA was related to the balance of the stress response and that NE decreased this response. These effects were specific to stress since levodopa/carbidopa did not induce changes in cortisol in non-stressed fish.

Estrogen is considered to be an endocrine disrupter and is becoming increasingly more prevalent in the daily life of humans. In some cases, estrogen is not fully metabolized by organisms and may be excreted in either its original form or in organic complex forms, into water residue systems reaching concentrations of 0.05 ng.L

Made available in DSpace on 2020-12-12T01:30:00Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-01-01 Due to human activities, there is an increasing presence of agrochemicals residues in water bodies, which could be attributed to an increased use of these chemicals, incorrect disposal of packaging materials, and crop leaching. The effects of these residues on prey-predator relationship of aquatic animals are poorly known. Here, we show that fish acutely exposed to glyphosate, 2,4-D, and methylbenzoate-based agrichemicals have their anti-predatory responses impaired. We exposed zebrafish to sub-lethal concentrations of agrichemicals and evaluated their behavioral reaction against a simulated bird predatory strike. We observed that agrichemical-exposed fish spent more time in a risky area, suggesting that the pesticides interfered with their ability of risk perception. Our results highlight the impairment and environmental consequences of agrochemical residues, which can affect aquatic life and crucial elements for life (food web) such as the prey-predator relationship. Programa de Pós-Graduação em Ciências Ambientais Universidade de Passo Fundo (UPF), BR 285, São José Programa de Pós-Graduação em Bioexperimentação Universidade de Passo Fundo (UPF), BR 285, São José Programa de Pós-Graduação em Farmacologia Universidade Federal de Santa Maria (UFSM), Av. Roraima, 1000, Cidade Universitária, Camobi Curso de Medicina Veterinária Faculdades Integradas do Vale do Iguaçu (Uniguaçu), Rua Padre Saporiti, 717, Rio D’Areia Curso de Medicina Veterinária Universidade de Passo Fundo (UPF), BR 285, São José Department of Structural and Functional Biology Institute of Biosciences of Botucatu CAUNESP UNESP Department of Structural and Functional Biology Institute of Biosciences of Botucatu CAUNESP UNESP

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.

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. CAF alone caused a social impairment, increase in mitochondrial energy metabolism and nitric oxide. MPH alone induced antisocial behavior. Despite MPH inhibited lipid peroxidation, it increased protein carbonylation. 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.

Made available in DSpace on 2020-12-10T17:35:39Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-08-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) FAPERGS University of Passo Fundo (UPF) Fundacao de Amparo a Pesquisa do Estado do Rio Grande do Sul (FAPERGS) 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. Univ Fed Santa Maria, Programa Posgrad Farmacol, Santa Maria, RS, Brazil Univ Passo Fundo, Programa Posgrad Bioexpt, Passo Fundo, RS, Brazil Univ Passo Fundo, Curso Med Vet, Passo Fundo, RS, Brazil Univ Estadual Paulista, Dept Biociencias, Botucatu, SP, Brazil Univ Passo Fundo, Programa Posgrad Ciencias Ambientais, Passo Fundo, RS, Brazil Univ Estadual Paulista, Dept Biociencias, Botucatu, SP, Brazil CAPES: 001 Fundacao de Amparo a Pesquisa do Estado do Rio Grande do Sul (FAPERGS): 18/2551-0000-493-6 Fundacao de Amparo a Pesquisa do Estado do Rio Grande do Sul (FAPERGS): 19/2551-0001-873-8 CNPq: 303263/2018-0