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1.
Anim Reprod Sci ; 225: 106669, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33360163

RESUMO

Anesthesia is a common practice used in fish research and aquaculture. It is important to understand anesthetic effects on the animal and tissues of interest to ensure validity of data and to improve animal welfare in research and fish production endeavors. The production of some captive fish species is only possible by imposing artificial reproduction procedures, and manipulation of fish for these purposes is a stressor. The purpose of this study, therefore, was to evaluate effects of different concentrations (100, 200, and 300 mg/L) of the anesthetic MS-222 (tricaine methanesulfonate) on cortisol concentrations and effects on sperm quality in Rhamdia quelen. After hormonal induction of gamete production, 28 sexually mature males were randomly assigned to treatments, and milt and blood samples were collected. Anesthesia induction time, motility rate, sperm concentration and morphology, plasma cortisol concentrations, and reproductive hormone concentrations (testosterone, 17-α-hydroxyprogesterone, and estradiol) were evaluated. Sperm motility was greater in the control than 300 mg/L treatment group but did not differ among the control, 100, and 200 mg/L groups. The estradiol concentration was greater in non- anesthetized than anesthetized Rhamdia quelen, but plasma cortisol concentrations did not differ among treatment groups (182.50 ±â€¯42.03 ng/mL). The anesthetic MS-222 at concentrations of 100, 200, and 300 mg/L did not inhibit the stress response due to handling of Rhamdia quelen males. In addition, treatment with MS-222 was not effective in inhibiting detrimental effects on sperm quality because this treatment was associated with impaired sperm motility and lesser concentrations of plasma estradiol.

2.
Front Behav Neurosci ; 14: 103, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32625070

RESUMO

Pyriproxyfen is one of the most used larvicides and insecticides; it acts as an analog of juvenile insect hormone (a growth regulator). It is highly toxic during all stages of mosquito development, suppresses metamorphosis, and interferes in insect reproduction and proliferation. Pyriproxyfen and its main metabolite have been shown to affect brain development in rodents. This compound is employed mainly to eliminate outbreaks of the genus Aedes, even in potable water. Despite the increasing number of toxicological studies about larvicides and insecticides-with an indication of continuous use-there have been few studies about the effects of pyriproxyfen in non-target species such as fish. This study evaluated the effects of pyriproxyfen on behavioral, cognitive, and endocrine parameters in zebrafish. We exposed adult zebrafish to different pyriproxyfen (Pestanal®) concentrations (0.125, 0.675, and 1.75 mg/l) for 96 h. We analyzed behavioral parameters, memory, cortisol levels, and gene expression of glucocorticoid receptor (gr) and corticotrophin-releasing factor (crf) after pyriproxyfen exposure. This exposure did not alter locomotion (distance or mean speed), anxiety-like behavior (latency to enter to the top zone of the tank or time in the top zone of the tank), and social or aggressive behavior. However, there was impaired inhibitory avoidance memory at all tested pyriproxyfen concentrations. Cortisol levels were reduced in exposed groups when compared to control or vehicle. However, gr and crf gene expression in pyriproxyfen-treated animals were unaltered when compared to control or vehicle groups. Taken together, these findings indicate that pyriproxyfen may induce cognitive impairment and altered cortisol levels in zebrafish, a non-target species.

3.
Neurobiol Learn Mem ; 155: 249-260, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30086397

RESUMO

This study aims to establish a protocol for evaluating the object recognition memory and object location tasks in zebrafish. We evaluated novel the object recognition memory and analyzed the exploration time of the objects during training and testing. Zebrafish explored more the new object in comparison to the familiar object (61% of exploration time during test session). We also tested the object location task and measured the exploration time of each object in the familiar and novel object location. There was a preference to explore the object in the novel location (63% of exploration time during test session). The effect of the non-competitive NMDA receptor antagonist MK-801 was investigated on the object recognition and object location memory. Control (water only) and treated animals (5 µM MK-801) presented a significant preference in exploring the familiar object in comparison to the new object (66 and 68% of exploration time, respectively, during test session); however, 10 µM MK-801-treated animals did not show differences in the exploration time of the objects. In the object location task, the animals treated with the 5 or 10 µM MK-801 did not show a preference for the familiar or novel location whereas the control group had a higher preference in exploring the object in the familiar location (64% of exploration time during test session). Considering the different responses of the control group between original task and in the regimen treatment, we evaluated the impact of habituation on cortisol levels of animals in three different protocols: (1) habituated at the experiment apparatus for 3 days (C1 condition), (2) habituated at the experiment apparatus for 3 days plus treatment tank exposure at fourth day (C2 condition), (3) habituated at the treatment tank and experiment apparatus for 3 days and exposed to treatment tank again at fourth day (C3 condition). The results showed higher levels of cortisol in animals submitted to C2 and C3 conditions compared to animals submitted to C1. When introduced to an acute stressor during C1 condition, we observed an increase in the cortisol levels and an absence of preference for the objects in comparison to control group, which had a preference for novel object and novel location. Fluoxetine treatment induced a decrease in cortisol levels and an absence of preference for the objects in C2 and C3 conditions in comparison to control group, which had a preference for familiar object. However, fluoxetine treatment induced a preference to the novel location in C2 and C3 conditions in comparison to control group, which had a preference for familiar location. These results indicate that treatment tank exposure induced a different performance in object recognition and object location memory due to stress responses. Therefore, these tasks are prone to evaluate memory in physiological and pathological conditions, but its use is limited due to sensitivity to stress caused by manipulation.


Assuntos
Comportamento Exploratório/fisiologia , Habituação Psicofisiológica/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Receptores de N-Metil-D-Aspartato/fisiologia , Reconhecimento Psicológico/fisiologia , Comportamento Espacial , Estresse Psicológico/psicologia , Animais , Maleato de Dizocilpina , Hidrocortisona/análise , Percepção Espacial/fisiologia , Peixe-Zebra
4.
PeerJ ; 5: e3739, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28890851

RESUMO

Chemical communication relating to predation risk is a trait common among fish species. Prey fish under threat of predation can signal risk to conspecific fish, which then exhibit defensive responses. Fish also assess predation risk by visual cues and change their behavior accordingly. Here, we explored whether these behavioral changes act as visual alarm signals to conspecific fish that are not initially under risk. We show that shoals of zebrafish (Danio rerio) visually exposed to a predator display antipredator behaviors. In addition, these defensive maneuvers trigger antipredator reactions in conspecifics and, concomitantly, stimulate the hypothalamus-pituitary-interrenal axis, leading to cortisol increase. Thus, we conclude that zebrafish defensive behaviors act as visual alarm cues that induce antipredator and stress response in conspecific fish.

5.
Artigo em Inglês | MEDLINE | ID: mdl-27778069

RESUMO

In fish, defensive reactions are induced by different chemical cues that emanate from sense-related stresses [physical, chemical, and visual (visual contact with predator)] or food stresses (acute fasting and chronic food restriction). Using a shuttle box with a two-chamber unmixed laminar flow that allowed fish to remain or flee from a chemical cue, we showed that the avoidance response depended on the type of the chemical cue. We show that zebrafish (Danio rerio) retreated from water conditioned with chemical cues released by chemically or physically stressed fish and acutely fasted fish, but not from water with cues from fish experiencing visual contact with predatory fish or fish suffering from chronic food restriction. Our data reinforced the hypothesis that fish use a combination of information and the context of the situation to determine their evasion strategy.


Assuntos
Água/química , Peixe-Zebra , Animais , Aprendizagem da Esquiva/fisiologia , Comportamento de Escolha , Sinais (Psicologia) , Privação de Alimentos/fisiologia , Comportamento Predatório/fisiologia , Estresse Fisiológico/fisiologia , Natação , Percepção Visual , Peixe-Zebra/fisiologia
6.
Sci Rep ; 6: 28986, 2016 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-27351465

RESUMO

Here we provide evidence that both pharmacological and environmental manipulations similarly blunt the cortisol release in response to an acute stressor in adult zebrafish. Different groups of fish were maintained isolated or group-housed in barren or enriched tanks, and then exposed or not to diazepam or fluoxetine. Acute stress increased cortisol levels in group-housed zebrafish maintained in barren environment. Single-housed zebrafish displayed a blunted cortisol response to stress. Environmental enrichment also blunted the stress response and this was observed in both isolated and group-housed fish. The same blunting effect was observed in zebrafish exposed to diazepam or fluoxetine. We highlighted environmental enrichment as an alternative and/or complimentary therapeutic for reducing stress and as a promoter of animal welfare.


Assuntos
Exposição Ambiental , Estresse Fisiológico/efeitos dos fármacos , Peixe-Zebra/fisiologia , Animais , Diazepam/metabolismo , Fluoxetina/metabolismo , Abrigo para Animais , Hidrocortisona/metabolismo
7.
Environ Toxicol Pharmacol ; 41: 89-94, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26667671

RESUMO

The contamination of rivers and other natural water bodies, including underground waters, is a current reality. Human occupation and some economic activities generate a wide range of contaminated effluents that reach these water resources, including psychotropic drug residues. Here we show that fluoxetine, diazepam and risperidone affected the initial development of zebrafish. All drugs increased mortality rate and heart frequency and decreased larvae length. In addition, risperidone and fluoxetine decreased egg hatching. The overall results points to a strong potential of these drugs to cause a negative impact on zebrafish initial development and, since the larvae viability was reduced, promote adverse effects at the population level. We hypothesized that eggs and larvae absorbed the drugs that exert its effects in the central nervous system. These effects on early development may have significant environmental implications.


Assuntos
Embrião não Mamífero/efeitos dos fármacos , Desenvolvimento Embrionário/efeitos dos fármacos , Psicotrópicos/toxicidade , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/crescimento & desenvolvimento , Animais , Diazepam/toxicidade , Feminino , Fluoxetina/toxicidade , Larva/efeitos dos fármacos , Masculino , Mortalidade , Risperidona/toxicidade , Peixe-Zebra/embriologia
8.
Artigo em Inglês | MEDLINE | ID: mdl-26325205

RESUMO

Psychotropic medications are widely used, and their prescription has increased worldwide, consequently increasing their presence in aquatic environments. Therefore, aquatic organisms can be exposed to psychotropic drugs that may be potentially dangerous, raising the question of whether these drugs are attractive or aversive to fish. To answer this question, adult zebrafish were tested in a chamber that allows the fish to escape or seek a lane of contaminated water. These attraction and aversion paradigms were evaluated by exposing the zebrafish to the presence of acute contamination with these compounds. The zebrafish were attracted by certain concentrations of diazepam, fluoxetine, risperidone and buspirone, which were most likely detected by olfaction, because this behavior was absent in anosmic fish. These findings suggest that despite their deleterious effects, certain psychoactive drugs attract fish.


Assuntos
Aprendizagem da Esquiva/efeitos dos fármacos , Psicotrópicos/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Aprendizagem da Esquiva/fisiologia , Relação Dose-Resposta a Droga , Feminino , Masculino , Atividade Motora/efeitos dos fármacos , Atividade Motora/fisiologia , Peixe-Zebra
9.
PLoS One ; 10(10): e0140800, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26473477

RESUMO

The presence of drugs and their metabolites in surface waters and municipal effluents has been reported in several studies, but its impacts on aquatic organisms are not yet well understood. This study investigated the effects of acute exposure to the antipsychotic risperidone on the stress and behavioral responses in zebrafish. It became clear that intermediate concentration of risperidone inhibited the hypothalamic-pituitary-interrenal axis and displayed anxiolytic-like effects in zebrafish. The data presented here suggest that the presence of this antipsychotic in aquatic environments can alter neuroendocrine and behavior profiles in zebrafish.


Assuntos
Ansiolíticos/efeitos adversos , Sistema Hipotálamo-Hipofisário/metabolismo , Sistema Hipófise-Suprarrenal/metabolismo , Risperidona/efeitos adversos , Poluentes Químicos da Água/efeitos adversos , Peixe-Zebra/metabolismo , Animais , Ansiolíticos/farmacologia , Comportamento Animal/efeitos dos fármacos , Sistema Hipotálamo-Hipofisário/patologia , Sistema Hipófise-Suprarrenal/patologia , Risperidona/farmacologia , Poluentes Químicos da Água/farmacologia
10.
Environ Toxicol Pharmacol ; 40(3): 704-7, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26414864

RESUMO

The presence of fluoxetine in aquatic environments has been reported for decades. Here, we investigate the effects of exposure to fluoxetine on the stress response and osmoregulation in zebrafish. We show that stress response alters osmoregulation and that fluoxetine inhibits these stress-related changes in osmoregulation. The results suggest that the presence of fluoxetine in aquatic ecosystems can cause changes in response to stress and osmoregulation in fish.


Assuntos
Fluoxetina/toxicidade , Osmorregulação/efeitos dos fármacos , Estresse Fisiológico/efeitos dos fármacos , Animais , Feminino , Masculino , Poluentes Químicos da Água/toxicidade , Peixe-Zebra
11.
Physiol Behav ; 139: 182-7, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25449397

RESUMO

Here, we show that individually housed zebrafish presented a reduced cortisol response to an acute stressor (persecution with a pen net for 120 s) compared to zebrafish housed in groups of 10. We hypothesized that the cortisol response to stress was reduced in individually housed zebrafish because they depend solely on their own perceptions of the stressor, whereas among grouped zebrafish, the stress response might be augmented by chemical and/or behavioral cues from the other members of the shoal. This hypothesis was based on previous described chemical communication of stress in fish as well on individual variation in stressor perception and potential individual differences in fish personality.


Assuntos
Hidrocortisona/metabolismo , Comportamento Social , Isolamento Social , Estresse Psicológico/fisiopatologia , Peixe-Zebra/fisiologia , Animais , Feminino , Abrigo para Animais , Masculino , Percepção , Isolamento Social/psicologia
12.
PLoS One ; 9(7): e103232, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25054216

RESUMO

The presence of pharmaceutical products in the aquatic environment has been reported in several studies. However, the impact of these drugs on living organisms is still uncharacterized. Here, we investigated the effects of acute exposure to either diazepam or fluoxetine on the stress response in Danio rerio. We showed that diazepam and fluoxetine inhibited the stress axis in zebrafish. Intermediate concentrations of diazepam suppressed the stress response as measured by cortisol levels, whereas fluoxetine inhibited cortisol increase at concentrations similar to those found in the environment. These data suggest that the presence of psychoactive drugs in aquatic ecosystems could cause neuroendocrine dysfunction in fish.


Assuntos
Ansiolíticos/farmacologia , Antidepressivos de Segunda Geração/farmacologia , Diazepam/farmacologia , Fluoxetina/farmacologia , Estresse Fisiológico/efeitos dos fármacos , Poluentes Químicos da Água/farmacologia , Peixe-Zebra/fisiologia , Animais , Feminino , Masculino
13.
Chemosphere ; 112: 85-91, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25048892

RESUMO

We studied the stress response of Rhamdia quelen fingerlings at 45, 90, 135 and 180 d following acute exposure to agrichemicals. Herein, we report the novel observation that acute exposure of fingerling-aged fish to a methyl parathion-based insecticide (MPBI) and to a tebuconazole-based fungicide (TBF) induced chronic inhibition of the stress response. In contrast, fish exposed to an atrazine-simazine-based herbicide (ASBH) recovered the stress response on day 45, and fish exposed to a glyphosate-based herbicide (GBH) did not present stress response inhibition. Additionally, fish exposed to MPBI, GBH and ASBH showed lower survival rates and attained lower final weights. In the case of TBF, the presence of the stressful stimulus more strongly influenced the changes in the performance parameters than did the agrichemical exposure itself. An impairment of the cortisol response may seriously hamper the adaptive response and the ability to promote the necessary metabolic and ionic adjustments to respond to environmental stress.


Assuntos
Peixes-Gato/fisiologia , Hidrocortisona/antagonistas & inibidores , Praguicidas/toxicidade , Estresse Fisiológico/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Metil Paration/toxicidade , Taxa de Sobrevida , Fatores de Tempo
14.
PLoS One ; 8(10): e74499, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24098336

RESUMO

In southern South America and other parts of the world, aquaculture is an activity that complements agriculture. Small amounts of agrichemicals can reach aquaculture ponds, which results in numerous problems caused by oxidative stress in non-target organisms. Substances that can prevent or reverse agrichemical-induced oxidative damage may be used to combat these effects. This study includes four experiments. In each experiment, 96 mixed-sex, 6-month-old Rhamdia quelen (118±15 g) were distributed into eight experimental groups: a control group that was not exposed to contaminated water, three groups that were exposed to various concentrations of bee products, three groups that were exposed to various concentrations of bee products plus tebuconazole (TEB; Folicur 200 CE™) and a group that was exposed to 0.88 mg L(-1) of TEB alone (corresponding to 16.6% of the 96-h LC50). We show that waterborne bee products, including royal jelly (RJ), honey (H), bee pollen (BP) and propolis (P), reversed the oxidative damage caused by exposure to TEB. These effects were likely caused by the high polyphenol contents of these bee-derived compounds. The most likely mechanism of action for the protective effects of bee products against tissue oxidation and the resultant damage is that the enzymatic activities of superoxide dismutase (SOD), catalase (CAT) and glutathione-S-transferase (GST) are increased.


Assuntos
Antioxidantes/farmacologia , Abelhas/metabolismo , Peixes-Gato/metabolismo , Fungicidas Industriais/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Triazóis/toxicidade , Animais , Mel/análise , Pólen/metabolismo
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