Publications by authors named "Ana Carolina Luchiari"

23 Publications

  • Page 1 of 1

Embryonic ethanol exposure on zebrafish early development.

Brain Behav 2021 May 3:e02062. Epub 2021 May 3.

Physiology and Behavior Department, Federal University of Rio Grande do Norte, Natal, Brazil.

Introduction: Embryonic exposure to ethanol leads to a condition of physical, behavioral, and cognitive deficiencies named fetal alcohol spectrum disorders (FASD). The most severe variations are in fetal alcohol syndrome (FAS), which is easier to diagnose and not studied in animal models. On the other side, the pFAS (partial fetal alcohol syndrome) includes cases of alcohol-related congenital disabilities and neurodevelopmental disorder with an inconclusive diagnosis. In recent years, the zebrafish has become a valuable model to study FASD and its variations.

Methods: This study characterizes the zebrafish embryonic and larval development after low and moderate ethanol concentration exposure. Fish eggs were exposed to 0.0%, 0.25%, 0.5%, and 1.0% ethanol at 24 hr postfertilization, and embryonic development was observed every 8 hr up to 120 hpf. It evaluated movements, phenotypic abnormalities, hatching, cardiac function and heartbeat frequency, larvae length at 120 hpf, and the apoptotic cells' fluorescence stained with acridine orange.

Results: Embryonic exposure to 0.5% and 1% ethanol presented reduced body size, decreased heartbeat rate, higher numbers of apoptotic cells, and hatching time differences.

Conclusions: Our results suggest any ethanol exposure during embryogenesis can be harmful and reinforces zebrafish as a suitable model for fetal alcohol spectrum disorders (FASD).
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/brb3.2062DOI Listing
May 2021

Does early ethanol exposure increase seeking-like behavior in zebrafish?

Int J Dev Neurosci 2021 Apr 10. Epub 2021 Apr 10.

Departamento de Fisiologia e Comportamento, Universidade Federal do Rio Grande do Norte, Natal, Brazil.

Fetal alcohol spectrum disorder (FASD) is the most common cause of birth defects. The severe variations are in fetal alcohol syndrome (FAS) but the most frequent cases are alcohol-related neurodevelopmental disorder (ARND), which is of a difficult diagnosis. ARND characteristics include impaired social behavior, anxiety and depression prevalence, cognitive deficits, and an increased chance for drug addiction. Here, we aimed to test whether early alcohol exposure leads to later alcohol preference. We hypothesize that early alcohol exposure increases the reinforcing effects on later experiences, raising the chance of addiction in adult life. Lately, the zebrafish has been a valuable model on alcohol research, allowing embryonic exposure and the study of the ontogenetic effects. For this, embryos were exposed to three different alcohol treatments: 0.0%, 0.25% and 0.5%, for 2 hr, at 24-hr post-fertilization. Then we evaluated the effects of embryonic alcohol exposure on conditioned place preference in two developmental stage: fry (10 days post-fertilization (dpf)) and young (90 dpf) zebrafish. Results show that control fish presented alcohol associative learning, which means, changes in place preference due to alcohol exposure, at both ontogenetic phases. However, zebrafish exposed to 0.25 and 0.5% alcohol during embryogenesis did not show conditioning response at any evaluated stage. These results suggest perception and cognitive deficits due to embryonic alcohol exposure that can alter alcohol responsiveness throughout a lifetime. Although low alcohol doses do not provoke malformation, it has been shown to induce several neurological and behavioral changes that are termed as Alcohol-Related Neurodevelopmental Disorders. These results may contribute to future investigations on how embryonic exposure affects the neurocircuitry related to perception and associative learning processing.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/jdn.10112DOI Listing
April 2021

Editorial: Zebrafish Cognition and Behavior.

Front Behav Neurosci 2021 16;15:659501. Epub 2021 Mar 16.

Department of Psychology, University of Toronto Mississauga, Mississauga, ON, Canada.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fnbeh.2021.659501DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8007767PMC
March 2021

Individual differences guide mate choice in the fighting fish (Betta splendens).

J Comp Psychol 2021 Jan 21. Epub 2021 Jan 21.

Physiology and Behavior Department.

Individual differences in behavior are observed in the variety of ways animals respond to environmental challenges, interact in a social group, take risks to access a resource, and so forth. In the present study, we investigated the behavioral reactions of male and female Siamese fighting fish () in different contexts and how they affect female mate choice. A total of 100 females and 50 males were classified according to boldness, sociability, and aggression, and then female mate choice was observed based on male profile and body color. Our results showed sex-related differences in Siamese fighting fish behavioral profiles: Males exhibited a higher correlation with aggression and females with boldness. Both male and female behavioral profile affected female mate choice. Females preferred bold red and nonaggressive red males. Sex-related differences in behavioral profiles may reflect ecological differences between male and female Siamese fighting fish. Female mate choice could be related to behavioral profiles that indicate better parental care, as male features may influence parental care decisions and the development of offspring behavioral profiles. (PsycInfo Database Record (c) 2021 APA, all rights reserved).
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1037/com0000267DOI Listing
January 2021

Early Mistreatment Contributes to Social Behavior Disorders in Zebrafish.

Front Behav Neurosci 2020 16;14:578242. Epub 2020 Oct 16.

Departamento de Fisiologia e Comportamento, Centro de Biociências, Universidade Federal do Rio Grande do Norte, Natal, Brazil.

Adverse experiences during childhood have been the focus of a series of studies due to the psychological damage observed in individuals who suffered abuse during their youth. Studies with model animals that can mimic these observations can significantly contribute to understanding the mechanisms behind this phenomenon. In our experiments, young zebrafish (20 dpf) were exposed to aggressive alcoholized male adults for 30 min for 10 days. At 30 dpf, the animals were tested for shoal formation, and at 60 dpf, locomotion and aggression were evaluated. Animals that suffered oppression from adults showed greater group cohesion and lower attack emission and higher distance from the image in the mirror test. Locomotor parameters were not changed. These results show that the stress caused by aggression exposure in the juvenile phase led to increased fear and avoidance behavior later in life. Moreover, we confirm the importance of the zebrafish as a sensitive tool for studies on the effects of early mistreatment and its consequences to adult behavior.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fnbeh.2020.578242DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7596165PMC
October 2020

Erythroxylum pungens Tropane Alkaloids: GC-MS Analysis and the Bioactive Potential of 3-(2-methylbutyryloxy)tropan-6,7-diol in Zebrafish (Danio rerio).

Planta Med 2021 Feb 11;87(1-02):177-186. Epub 2020 Nov 11.

Department of Pharmacy, Federal University of Rio Grande do Norte, Natal, RN, Brazil.

Tropane alkaloids are specialized plant metabolites mostly found in the Erythroxylaceae and Solanaceae families. Although tropane alkaloids have a high degree of structural similarity because of the tropane ring, their pharmacological actions are quite distinct. Brazil is one of the main hotspots of spp. diversity with 123 species (almost 66% of the species catalogued in tropical America). occurs in the Caatinga, a promising biome that provides bioactive compounds, including tropane alkaloids. As part of our efforts to investigate this species, 15 alkaloids in specimens harvested under different environmental conditions are presented herein. The occurrence of 3-(2-methylbutyryloxy)tropan-6,7-diol in the stem bark of plants growing in their natural habitat, greenhouse controlled conditions, and after a period of water restriction, suggests that it is a potential chemical marker for the species. This alkaloid was evaluated for several parameters in zebrafish () as a model organism. Regarding toxicity, teratogenic effects were observed at 19.5 µM and the lethal dose for embryos was 18.4 µM. No mortality was observed in adults, but a behavioral screen showed psychostimulatory action at 116.7 µM. Overall, the alkaloid was able to cause zebrafish behavioral changes, prompting further investigation of its potential as a new molecule in the treatment of depression-like symptoms. , targets involved in antidepressant pathways were identified by docking.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1055/a-1264-4302DOI Listing
February 2021

Zebrafish as an Emerging Model System in the Global South: Two Decades of Research in Brazil.

Zebrafish 2020 12 20;17(6):412-425. Epub 2020 Oct 20.

Laboratory of Environmental Biotechnology and Ecotoxicology, Department of Biosciences and Technology, Institute of Tropical Pathology and Public Health, Federal University of Goiás, Goiânia, Brazil.

The zebrafish () is an emerging model system in several research areas worldwide, especially in the Global South. In this context, the present study revised the historical use and trends of zebrafish as experimental models in Brazil. The data concerning the bibliometric parameters, research areas, geographic distribution, experimental design, zebrafish strain, and reporter lines, as well as recent advances were revised. In addition, the comparative trends of Brazilian and global research were discussed. Revised data showed the rapid growth of Brazilian scientific production using zebrafish as a model, especially in three main research areas (Neuroscience &and Behavior, Pharmacology and Toxicology, and Environment/Ecology). Studies were conducted in 19 Brazilian states (70.37%), confirming the wide geographic distribution and importance of zebrafish research. Results indicated that research related to toxicological approaches are widespread in Global South countries such as Brazil. Studies were performed mainly using tests (89.58%) with adult fish (59.75%) and embryos (30.67%). Moreover, significant research gaps and recommendations for future research are presented. The present study shows that the zebrafish is a suitable vertebrate model system in the Global South.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1089/zeb.2020.1930DOI Listing
December 2020

Embryonic Exposure to Ethanol Increases Anxiety-Like Behavior in Fry Zebrafish.

Alcohol Alcohol 2020 Oct;55(6):581-590

Department of Physiology and Behavior, Universidade Federal do Rio Grande do Norte, Rio Grande do Norte, Brazil.

Aims: Fetal alcohol spectrum disorder (FASD) is an umbrella term to describe the effects of ethanol (Eth) exposure during embryonic development, including several conditions from malformation to cognitive deficits. Zebrafish (Danio rerio) are a translational model popularly applied in brain disorders and drug screening studies due to its genetic and physiology homology to humans added to its transparent eggs and fast development. In this study, we investigated how early ethanol exposure affects zebrafish behavior during the initial growth phase.

Methods: Fish eggs were exposed to 0.0 (control), 0.25 and 0.5% ethanol at 24 h post-fertilization. Later, fry zebrafish (10 days old) were tested in a novel tank task and an inhibitory avoidance protocol to inquire about morphology and behavioral alterations.

Results: Analysis of variance showed that ethanol doses of 0.25 and 0.5% do not cause morphological malformations and did not impair associative learning but increased anxiety-like behavior responses and lower exploratory behavior when compared to the control.

Conclusion: Our results demonstrate that one can detect behavioral abnormalities in the zebrafish induced by embryonic ethanol as early as 10 days post-fertilization and that alcohol increases anxious behavior during young development in zebrafish.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/alcalc/agaa087DOI Listing
October 2020

Damselfish face climate change: Impact of temperature and habitat structure on agonistic behavior.

PLoS One 2020 30;15(6):e0235389. Epub 2020 Jun 30.

Laboratório de Peixes, Departamento de Fisiologia e Comportamento, Centro de Biociências, Universidade Federal do Rio Grande do Norte, Natal, Brazil.

Oceans absorb a huge part of the atmospheric heat, leading to the rise in water temperature. Reefs are among the most affected ecosystems, where the complex behavioral repertoire of fishes is usually an indicator of environmental impacts. Here, we examined whether temperature (28 and 34°C) and habitat complexity (high and low) interact to affect the agonistic behavior (mirror test) of the dusky damselfish (Stegastes fuscus), a key species in Brazilian reefs because of its gardening capacity and territorial behavior. Higher temperatures altered basal behavior in both high and low-complexity conditions. Fish kept at 28°C under the high-complexity condition were more aggressive than those at a higher temperature (34°C) and in a low-complexity condition, which also exhibited lower dispersion. Our data show that changes in behavior of coral reef fish is associated to fluctuations in environmental conditions. Thus, it is important to implement management or conservation strategies that could mitigate global change effects.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0235389PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7326182PMC
September 2020

Behavioral Screening of Alcohol Effects and Individual Differences in Zebrafish (Danio rerio).

Alcohol Alcohol 2020 Oct;55(6):591-597

Department of Physiology and Behavior, Bioscience Center, Federal University of Rio Grande do Norte, Natal, Brazil.

Aim: To better understand the individual differences that make up a population, this study aimed to evaluate the effects of different alcoholic concentrations on the behavioral profiles of zebrafish (Danio rerio).

Methods: For this purpose, adult animals were separated into two behavioral profiles: bold and shy, according to the emergence order. Bold and shy fish were individually tested for exploration after exposure to the drug. Acute exposure treatments were alcohol 0.00, 0.10, 0.25 and 0.50%. The behavioral parameters evaluated were speed while moving, maximum speed, total distance traveled and distance from the bottom of the tank.

Results: For the groups that did not receive alcohol, bold animals showed higher speed while moving. Shy 0.00% and shy 0.10% had the highest maximum speed compared with other concentrations and profiles. For the distance from the bottom tank, our results showed that the increase induced by the low acute dose (0.10%) was observed for both profiles.

Conclusions: Our results corroborate with previous findings that alcohol affects the behavioral profiles of zebrafish differently, with bold animals apparently more resistant to these changes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/alcalc/agaa046DOI Listing
October 2020

Individual Differences in Hatching Time Predict Alcohol Response in Zebrafish.

Front Behav Neurosci 2019 23;13:166. Epub 2019 Jul 23.

Departamento de Fisiologia e Comportamento, Centro de Biociências, Universidade Federal do Rio Grande do Norte, Natal, Brazil.

There are significant individual differences in response to alcohol: some people seem to exhibit higher alcohol sensitivity, while others are more resistant. These differences are related to alcohol metabolism, inherited traits, environmental/social pressure, personal habits and other indeterminate causes. In order to test how individual differences in hatching time are related to behavioral response to different alcohol concentrations, we separated zebrafish larvae into two categories according to egg emergence time: eggs hatched between 48 and 72 hours post-fertilization (hpf) were considered early emerging (EE), while those hatched from 72 to 96 hpf were considered late emerging (LE). On the 30th day post fertilization, EE and LE fish were exposed to four alcohol concentrations: 0.00% (control), 0.10%, 0.25% and 0.50%, and behavior was recorded for 60 min. We observed average and maximum swimming speed, distance traveled, and freezing time (immobility that indicates state of anxiety). For EE fish, 0.10% alcohol did not change behavior, while 0.25% and 0.50% increased freezing and decreased locomotion. By contrast, LE fish increased locomotion when exposed to both 0.10 and 0.25% alcohol, and increased freezing time at 0.50% alcohol. These results show that zebrafish behavioral profiles exhibit different sensitivities to alcohol, likely due to traits that can be tracked from early life stages and may indicate individuals' predisposition to alcohol tolerance and dependence.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fnbeh.2019.00166DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6664016PMC
July 2019

Coffee time: Low caffeine dose promotes attention and focus in zebrafish.

Learn Behav 2019 09;47(3):227-233

Department of Physiology and Behavior, Bioscience Center, Universidade Federal do Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil.

In this study we investigated the ability of zebrafish to discriminate visual signs and associate them with a reward in an associative-learning protocol including distractors. Moreover, we studied the effects of caffeine on animal performance in the task. After being trained to associate a specific image pattern with a reward (food) in the presence of other, distractor images, the fish were challenged to locate the exact cue associated with the reward. The distractors were same-colored pattern images similar to the target. Both the target and distractors were continually moved around the tank. Fish were exposed to three caffeine concentrations for 14 days: 0 mg/L (control, n = 12), 10 mg/L (n = 14), and 50 mg/L (n = 14). Zebrafish spent most of the time close to the target (where the reward was offered) under the effects of 0 and 10 mg/L caffeine, and the shortest latency to reach the target was observed for the 10-mg/L caffeine group. Both caffeine treatments (10 and 50 mg/L) increased the average speed and distance traveled when compared to the control group. This study confirms previous results showing that zebrafish demonstrate conditioned learning ability; however, low-dose caffeine exposure seems to favor visual cue discrimination and to increase zebrafish performance in a multicue discrimination task, in which primarily focus and attention are required in order to obtain the reward.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3758/s13420-018-0369-3DOI Listing
September 2019

It's Tea Time: Interference of Ayahuasca Brew on Discriminative Learning in Zebrafish.

Front Behav Neurosci 2018 27;12:190. Epub 2018 Aug 27.

Departamento de Fisiologia, Centro de Biociências, Universidade Federal do Rio Grande do Norte, Natal, Brazil.

Ayahuasca is a psychoactive brew traditionally used in shamanistic and vegetalistic rituals and has recently received lot of attention due to potential cognitive benefits. Ayahuasca effects are caused by the synergistic interaction of β-carbolines (harmine, harmaline and tetrahydroarmine) contained in stalks combined with the N,N-dimethyltryptamine (DMT) from leaves, a potent agonist to serotonin (5-HT) receptors. The present study approaches the effects of chronic and acute exposure to two Ayahuasca concentrations (0.1 and 0.5 ml/L) on the cognitive ability to discriminate objects in a one-trial learning task in zebrafish. Based on the combination of concentrations and exposure regimens, we divided adult zebrafish in five treatment groups: acute 0.1 and 0.5 ml/L, chronic 0.1 and 0.5 ml/L, and control 0.0 ( = 20 for each group). Then we tested them in a memory task of object discrimination. Acute Ayahuasca exposed groups performed similarly to the control group, however chronically treated fish (13 days) presented both impaired discriminative performance and locomotor alterations. Overall, these results indicate that Ayahuasca is a potent psychoactive drug that, in chronic exposure, negatively affects mnemonic parameters in zebrafish. In single exposure it does not affects cognitive performance, but the higher concentration (0.5) affected locomotion. Moreover, we reinforce the importance of the zebrafish for behavioral pharmacological studies of drug screening, in special to psychedelic drug research.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fnbeh.2018.00190DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6119691PMC
August 2018

Sleep deprivation impairs cognitive performance in zebrafish: A matter of fact?

Behav Processes 2018 Dec 12;157:656-663. Epub 2018 Apr 12.

Departamento de Fisiologia, Centro de Biociências, Universidade Federal do Rio Grande do Norte, Av Sen Salgado Filho, 3000, Lagoa Nova, Natal, Brazil. Electronic address:

The zebrafish (Danio rerio) has become a valuable model organism for behavioral studies examining learning and memory. Its diurnal circadian rhythm and characterized sleep-like state make it comparable to mammals, features that have contributed to establishing this small vertebrate as a translational model for sleep research. Despite sleep being an evolutionarily conserved behavior, its mechanisms and functions are still debated. Sleep deprivation is commonly associated with decreased attention, reduced responsiveness to external stimuli, altered locomotor activity and impaired performance on cognitive tasks. In the current study, we examined the effects of partial and total sleep deprivation on zebrafish learning performance in an active avoidance conditioning paradigm. In addition, we examined the effects of two drugs known to alter sleep (alcohol and melatonin) on learning performance in sleep deprived animals. Our results suggest that although partial sleep deprivation did not alter learning performance, total sleep deprivation was found to significantly impair behavioral responses to the electric shock as well as avoidance learning. However, when sleep deprived fish were treated with alcohol the night before the learning task, learning performance was similar to the control group. In contrast, melatonin treatment did not alter learning performance in sleep deprived animals. We conclude that the zebrafish is a sensitive tool for investigating the effects of sleep deprivation on cognitive performance and may be a useful model for dissecting the mechanisms underlying learning and memory.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.beproc.2018.04.004DOI Listing
December 2018

"Not tonight zebrafish": the effects of Ruta graveolens on reproduction.

Pharm Biol 2018 Dec;56(1):60-66

c Departamento de Fisiologia, Centro de Biociências , Universidade Federal do Rio Grande do Norte , Natal , RN , Brazil.

Context: There is growing interest in the pharmacological evaluation of Rue due to its potential to treat a variety of clinical diseases. The plant seems to present potent endocrine disrupting effects, and its excretion and disposal are not a concern.

Objective: The effects of Ruta graveolens L. (Rutaceae) ethanol extract (RE) on reproductive behaviour, fertility, and steroid and thyroid hormone levels in zebrafish were investigated.

Material And Methods: We exposed subjects to varying concentrations of RE, and one-tenth the LC concentration (2.37 ppm) was established as the sublethal dose. After 2 weeks exposure, reproductive behaviour, cumulative number of eggs laid, percentage of fertilized eggs, and whole body steroid and thyroid hormones were measured.

Results: Reproductive association behaviour did not differ between control and RE-exposed animals, but spawning attempts were reduced in RE exposed animals. Cumulative egg production between days 9 to 14, RE exposed fish laid 672 eggs while control fish laid 1242 eggs. Also, percentage of fertilized eggs was higher for the control than for the RE exposed fish. Estradiol-17β (E2) levels were reduced in females exposed to RE and testosterone (T) was statistically lower in both males and females treated with RE. Furthermore, thyroid hormones (T3 and T4) declined in fish treated with RE.

Conclusion: RE has endocrine disrupting potential in fish, which has important implications for studying the effects of unintentional pharmaceutical exposure. Moreover, the results demonstrate that drug exposure may affect more than just the overall level of behaviour, emphasizing the relevance of examining the effects of individual exposure. We reinforce the use of zebrafish as a model organism in physiology and behaviour, and raise concerns about the toxic effects of RE in non-target organisms such as aquatic vertebrates, which may ultimately affect human health.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/13880209.2017.1421234DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6130722PMC
December 2018

Effects of Alcohol on Inhibitory Avoidance Learning in Zebrafish (Danio rerio).

Zebrafish 2017 10 17;14(5):430-437. Epub 2017 Jul 17.

Departamento de Fisiologia, Universidade Federal do Rio Grande do Norte , Natal, Brazil .

The zebrafish (Danio rerio) can be used in studies addressing the effects of drugs on learning, memory, and anxiety. In the present study, we investigated the effect of different alcohol treatments (chronic and acute) on the learning and anxiety response of zebrafish in an inhibitory avoidance paradigm. Zebrafish were initially exposed to different alcohol treatments and submitted to an inhibitory avoidance protocol, where an electroshock was applied to the fish as they swam from the white to the black side of a shuttle box tank (naturally preferred environment of zebrafish). Animals from the control and 0.5% acute alcohol groups exhibited high latency to enter the black side of the tank after the first exposure to electroshock, in addition to higher freezing and a shorter distance from the bottom of the tank, suggesting acute alcohol exposure did not affect aversive learning in zebrafish. However, chronic exposure and alcohol withdrawal impaired the fish's capacity to properly respond to the aversive stimulus. Overall, our results show the harmful effects of chronic alcohol exposure, both continued intake and its cessation, but avoidance behavior persisted and anxiety increased following acute alcohol exposure.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1089/zeb.2017.1438DOI Listing
October 2017

Good night, sleep tight: The effects of sleep deprivation on spatial associative learning in zebrafish.

Pharmacol Biochem Behav 2017 08 23;159:36-47. Epub 2017 Jun 23.

Departamento de Fisiologia, Centro de Biociências, Universidade Federal do Rio Grande do Norte, Natal, Brazil. Electronic address:

Learning and memory are vital to an animal's survival, and numerous factors can disrupt cognitive performance. Sleep is an evolutionarily conserved physiological process known to be important for the consolidation of learning and memory. The zebrafish has emerged as a powerful model organism sharing organizational and functional characteristics with other vertebrates, providing great translational relevance. In our study, we used a simple spatial associative learning task to quantify the effects of sleep deprivation (partial vs. total) on learning performance in zebrafish, using an animated conspecific shoal image as a reward. Control animals maintained on a regular light:dark cycle were able to acquire the association between the unconditioned and conditioned stimulus, reinforcing zebrafish as a valid and reliable model for appetitive conditioning tasks. Notably, sleep deprivation did not alter the perception of and response to the conspecific image. In contrast, although partial sleep deprivation did not impair cognitive performance, total sleep deprivation significantly impaired performance on the associative learning task. Our results suggest that sleep is important for learning and memory, and that the effects of sleep deprivation on these processes can be investigated in zebrafish.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.pbb.2017.06.011DOI Listing
August 2017

Time place learning and activity profile under constant light and constant dark in zebrafish (Danio rerio).

Behav Processes 2017 May 20;138:49-57. Epub 2017 Feb 20.

Departamento de Fisiologia, Centro de Biociências, Universidade Federal do Rio Grande do Norte, Natal, RN, Brazil. Electronic address:

The ability to learn about the signs of variability in space and time is known as time place learning (TPL). To adjust their circadian rhythms, animals use stimuli that change regularly, such as the light-dark cycle, temperature, food availability or even social stimuli. Because light-dark cycle is the most important environmental temporal cue, we asked how a diurnal animal would perform TPL if this cue was removed. Zebrafish has been extensively studied in the chronobiology area due to it diurnal chronotype, thus, we studied the effects of constant light and constant dark on the time-place learning and activity profile in zebrafish. Our data show that while under constant light and dark condition zebrafish was not able of TPL, after 30days under the constant conditions, constant light led to higher activity level and less significant (robust) 24h rhythm.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.beproc.2017.02.015DOI Listing
May 2017

Sleep deprivation effects on object discrimination task in zebrafish (Danio rerio).

Anim Cogn 2017 Mar 19;20(2):159-169. Epub 2016 Sep 19.

Departamento de Fisiologia, Centro de Biociências, Universidade Federal do Rio Grande do Norte, PO BOX 1511, Natal, Rio Grande do Norte, 59078-970, Brazil.

The zebrafish is an ideal vertebrate model for neurobehavioral studies with translational relevance to humans. Many aspects of sleep have been studied, but we still do not understand how and why sleep deprivation alters behavioral and physiological processes. A number of hypotheses suggest its role in memory consolidation. In this respect, the aim of this study was to analyze the effects of sleep deprivation on memory in zebrafish (Danio rerio), using an object discrimination paradigm. Four treatments were tested: control, partial sleep deprivation, total sleep deprivation by light pulses, and total sleep deprivation by extended light. The control group explored the new object more than the known object, indicating clear discrimination. The partially sleep-deprived group explored the new object more than the other object in the discrimination phase, suggesting a certain degree of discriminative performance. By contrast, both total sleep deprivation groups equally explored all objects, regardless of their novelty. It seems that only one night of sleep deprivation is enough to affect discriminative response in zebrafish, indicating its negative impact on cognitive processes. We suggest that this study could be a useful screening tool for cognitive dysfunction and a better understanding of the effect of sleep-wake cycles on cognition.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10071-016-1034-xDOI Listing
March 2017

Time-place learning in the zebrafish (Danio rerio).

Behav Processes 2016 Jul 14;128:64-9. Epub 2016 Apr 14.

Departamento de Fisiologia, Centro de Biociências, Universidade Federal do Rio Grande do Norte, Natal, RN, Brazil. Electronic address:

Animals exhibit activity cycles that repeat over days. The most noteworthy cyclical behaviors are related to forraging, which generally occur at the same times and locations. The synchronization of animal activities via the association of different places at different times for the occurrence of relevant biological events is known as time-place learning (TPL). In the present study, we used zebrafish (Danio rerio) to test time-place learning based on a different stimulus: social reinforcement. Fish were not only able to associate time and place of the social stimulus, but also displayed anticipatory activity prior to the arrival of the stimulus. Furthermore, we show that the group of conspecifics is an relevant stimulus for time-place learning tasks, while other studies have only used food.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.beproc.2016.04.007DOI Listing
July 2016

Physical exercise improves learning in zebrafish, Danio rerio.

Behav Processes 2013 Nov 7;100:44-7. Epub 2013 Aug 7.

Departamento de Fisiologia, Centro de Biociências, Universidade Federal do Rio Grande do Norte, PO Box 1510, 59078-970 Natal, Rio Grande do Norte, Brazil. Electronic address:

Zebrafish is an ideal vertebrate model for neuroscience studies focusing on learning and memory. Although genetic manipulation of zebrafish is available, behavioral protocols are often lacking. In this study we tested whether physical activity can facilitate zebrafish's learning process in an associative conditioning task. Learning was inferred by the approach of the feeding area just after the conditioned stimulus (light). Unexercised zebrafish showed conditioning response from the 5th testing day while fish previously submitted to swim against the water current showed learning by the 3rd day of testing. It seems that physical activity may accelerate associative learning response in zebrafish, indicating the benefits of exercise for cognitive processes. We suggest that this preliminary work could be useful for high throughput screening.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.beproc.2013.07.020DOI Listing
November 2013

Time-place learning in individually reared angelfish, but not in pearl cichlid.

Behav Processes 2006 Nov 10;73(3):367-72. Epub 2006 Jun 10.

Departamento de Fisiologia, Instituto de Biociências, UNESP, Rabião Jr. s/n, Botucatu 18618-000, SP, Brazil.

Time-place learning based on food association was investigated in the cichlids angelfish (Pterophyllum scalare) and pearl cichlid (Geophagus brasiliensis) reared in isolation, therefore eliminating social influence on foraging. During a 30-day period, food was placed in one side of the aquarium (containing three compartments) in the morning and in the opposite side in the afternoon. Learning was inferred by the number of correct side choices of all fish in each day of test (15th and 30th). During the test day fish were not fed. The angelfish learned to switch sides at the correct day period in order to get food, suggesting this species has time-place learning ability when individually reared. On the other hand, the same was not observed for pearl cichlid.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.beproc.2006.06.001DOI Listing
November 2006

Ventilatory frequency indicates visual recognition of an allopatric predator in nai;ve Nile tilapia.

Behav Processes 2003 Jan;60(3):235-239

Departamento de Fisiologia, Instituto de Biociências, UNESP, 18618-000, SP, Botucatu, Brazil

Perceiving a possible predator may promote physiological changes to support prey 'fight or flight'. In this case, an increase in ventilatory frequency (VF) may be expected, because this is a way to improve oxygen uptake for escape tasks. Therefore, changes in VF may be used as a behavioral tool to evaluate visual recognition of a predator threat. Thus, we tested the effects of predator visual exposure on VF in the fish Nile tilapia, Oreochromis niloticus. For this, we measured tilapia VF before and after the presentation of three stimuli: an aquarium with a harmless fish or a predator or water (control). Nile tilapia VF increased significantly in the group visually exposed to a predator compared with the other two, which were similar to each other. Hence, we conclude that Nile tilapia may recognize an allopatric predator; consequently VF is an effective tool to indicate visual recognition of predator threat in fish.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/s0376-6357(02)00127-4DOI Listing
January 2003