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1.
Artigo em Inglês | MEDLINE | ID: mdl-33772638

RESUMO

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.

2.
Artigo em Inglês | MEDLINE | ID: mdl-32800866

RESUMO

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.

3.
Environ Sci Pollut Res Int ; 26(25): 26293-26303, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31286368

RESUMO

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.


Assuntos
Risperidona/toxicidade , Poluentes Químicos da Água/toxicidade , Peixe-Zebra , Animais , Comportamento Animal/efeitos dos fármacos , Ecotoxicologia/métodos , Embrião não Mamífero/efeitos dos fármacos , Feminino , Larva/efeitos dos fármacos , Masculino , Comportamento Predatório/efeitos dos fármacos , Peixe-Zebra/embriologia , Peixe-Zebra/fisiologia
4.
Arch Environ Contam Toxicol ; 77(3): 443-451, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31190101

RESUMO

Environmental contamination caused by the human occupancy and economic activities that generate a wide range of contaminated effluents that reach natural water resources, is a current reality. Residues of agrichemicals used in plant production were detected in different environments and in different countries. Among these agrochemicals, we studied a glyphosate-based herbicide (GBH), a fipronil-based insecticide (FBI), and their mixtures (GBH + FBI). Zebrafish exposed to 3 and 5 mg/L of GBH spend more time in the top zone and less time in the bottom zone. Fish exposed to 0.009 and 0.018 mg/L of FBI spent less time in the bottom zone, whereas zebrafish exposed to the three GBH + FBI mixtures spend more time in the top zone compared with unexposed control fish. This clear anxiolytic pattern, in an environmental context, can directly impair the ability of fish to avoid or evade predators. We concluded that both glyphosate-based herbicide and fipronil-based insecticide and their mixtures alter zebrafish behavior, which may result in significant repercussions on the maintenance of the species as well as on the food chain and the ecosystem.


Assuntos
Glicina/análogos & derivados , Praguicidas/toxicidade , Pirazóis/toxicidade , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/fisiologia , Animais , Comportamento Animal/efeitos dos fármacos , Ecossistema , Feminino , Glicina/toxicidade , Humanos , Masculino , Comportamento Predatório
5.
Sci Rep ; 8(1): 13908, 2018 09 17.
Artigo em Inglês | MEDLINE | ID: mdl-30224742

RESUMO

Here we show that the novel object recognition test can discriminate between high (HRN, neophobic) and low (LRN, neophilic) novelty responders in zebrafish populations. Especially when we observe the latency to the first entry in the novel object zone, zebrafish did not maintain these behavioral phenotypes in sequential tests and only the HRN group returned to their initial responsive behavior when exposed to fluoxetine. Our results have important implications for behavioral data analysis since such behavioral differences can potentially increase individual response variability and interfere with the outcomes obtained from various behavioral tasks. Our data reinforce the validity of personality determination in zebrafish since we show clear differences in behavior in response to fluoxetine.


Assuntos
Comportamento Animal/efeitos dos fármacos , Fluoxetina/farmacologia , Peixe-Zebra/fisiologia , Animais , Masculino
6.
Gen Comp Endocrinol ; 252: 236-238, 2017 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-28716505

RESUMO

In this article, we show that the tyrosine hydroxylase inhibitor α-Methyl-l-tyrosine (AMPT) decreased the responsiveness of the zebrafish stress axis to an acute stressful challenge. These effects were specific for responses to stimulation, since unstimulated (basal) cortisol levels were not altered by AMPT. Moreover, AMPT decreased the stress response 15min after stimulation, but not after that time period. To our knowledge, this is the first report about the effects of AMPT on the neuroendocrine axis of adult zebrafish in acute stress responses. Overall, these results suggest a mechanism of catecholamine-glucocorticoid interplay in neuroendocrine responses of fish, pointing an interesting avenue for physiological research, as well as an important endpoint that can be disrupted by environmental contamination. Further experiments will unravel the mechanisms by which AMPT blocked the cortisol response.


Assuntos
Inibidores Enzimáticos/farmacologia , Estresse Fisiológico/efeitos dos fármacos , Tirosina 3-Mono-Oxigenase/antagonistas & inibidores , Peixe-Zebra/fisiologia , alfa-Metiltirosina/farmacologia , Animais , Feminino , Hidrocortisona/sangue , Masculino , Tirosina 3-Mono-Oxigenase/metabolismo , Peixe-Zebra/sangue
7.
Arch Environ Contam Toxicol ; 71(3): 415-22, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27423874

RESUMO

In agriculture intensive areas, fishponds and natural water bodies located in close proximity to these fields receive water with variable amounts of agrichemicals. Consequently, toxic compounds reach nontarget organisms. For instance, aquatic organisms can be exposed to tebuconazole-based fungicides (TBF), glyphosate-based herbicides (GBH), and atrazine-based herbicides (ABH) that are potentially dangerous, which motivates the following question: Are these agrichemicals attractant or aversive to fish? To answer this question, adult zebrafish were tested in a chamber that allows fish to escape from or seek a lane of contaminated water. This attraction and aversion paradigm was evaluated with zebrafish in the presence of an acute contamination with these compounds. We showed that only GBH was aversive to fish, whereas ABH and TBF caused neither attraction nor aversion for zebrafish. Thus, these chemicals do not impose an extra toxic risk by being an attractant for fish, although TBF and ABH can be more deleterious, because they induce no aversive response. Because the uptake and bioaccumulation of chemicals in fish seems to be time- and dose-dependent, a fish that remains longer in the presence of these substances tends to absorb higher concentrations than one that escapes from contaminated sites.


Assuntos
Agroquímicos/toxicidade , Peixes/fisiologia , Poluentes Químicos da Água/toxicidade , Animais , Aprendizagem da Esquiva , Comportamento Animal , Testes de Toxicidade , Peixe-Zebra
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