Biology subjects

Marcon, M.

Publications and source records attributed to Marcon, M..

6 recordsLinked to original sources

bioRxiv2021

What do zebrafish prefer? Directional and color preferences in maze tasks

Studies regarding the animals innate preferences help elucidate and avoid probable sources of bias and serve as a reference to improve and develop new behavioral tasks. In zebrafish research, the results of innate directional and color preferences are often not replicated between research groups or even inside the same laboratory raising huge concerns on the replicability and reproducibility. Thus, this study aimed to investigate the male and female zebrafish innate directional and color preferences in the plus-maze and T-maze behavioral tasks. As revealed by the percentage of time spent in each zone of the maze, our results showed that males and females zebrafish demonstrated no difference in directional preference in the plus-maze task. Surprisingly, male and female zebrafish showed color preference differences in the plus-maze task; males did not show any color preference, while female zebrafish demonstrated a red preference compared to white, blue, and yellow colors. Moreover, both male and female zebrafish demonstrated a strong black color preference compared to the white color in the T-maze task. Thus, our results demonstrate the importance of innate preference assays involved with the directionality of the apparatus or the application of colors as a screening process conducting behavioral tests (e.g., anxiety, learning and memory assessment, locomotion, and preference) and highlight the need to analyze sex differences.

neuroscience↗

bioRxiv2021

Ochratoxin A induces behavioral and neurochemical changes in adult zebrafish

Ochratoxin A (OTA) is a mycotoxin produced by species of filamentous fungi widely found as a contaminant in food and with high toxic potential. Studies have shown that this toxin cause kidney and liver damage, however, data on the effects of exposure to OTA on the central nervous system are still scarce. Zebrafish (Danio rerio) is a teleost often used in translational research due to its physiological, genetic, and behavioral homology with mammals, in addition to being useful as an environmental bioindicator. Thus, this study aimed to investigate the effects of exposure to OTA on behavioral and neurochemical parameters in adult zebrafish. The animals were treated with different doses of OTA (1.38, 2.77, and 5.53 mg/kg) and submitted to behavioral evaluations in the open tank and social interaction tests. Subsequently, they were euthanized, and the brains were used to assess markers associated with oxidative status. In the open tank test OTA induced changes in distance, absolute turn angle, mean speed, and time-freezing. However, no significant effects were observed in the social interaction test. Moreover, OTA also induced alterations in neurochemical parameters with changes in non-protein thiols (NPSH), glutathione peroxidase (GPx), glutathione-S-transferase (GST), and glutathione reductase (GR). This study showed that OTA can affect neurobiological aspects in zebrafish even at low doses.

neuroscience↗

bioRxiv2021

Non-micronized and micronized curcumin do not prevent the behavioral and neurochemical effects induced by acute stress in zebrafish

Curcumin, a polyphenol extracted from the rhizome of Curcuma longa L. (Zingiberaceae), presents neuroprotective properties and can modulate neuronal pathways related to mental disorders. However, curcumin has low bioavailability, which can compromise its use. The micronization process can reduce the mean particle diameter and improve this compounds bioavailability and therapeutic potential. In this study, we compared the behavioral (in the open tank test, OTT) and neurochemical (thiobarbituric acid reactive substances (TBARS) and non-protein thiols (NPSH) levels) effects of non-micronized curcumin (CUR, 10 mg/kg, i.p.) and micronized curcumin (MC, 10 mg/kg, i.p.) in adult zebrafish subjected to 90-minute acute restraint stress (ARS). ARS increased the time spent in the central area and the number of crossings and decreased the immobility time of the animals. These results suggest an increase in locomotor activity and a decrease in thigmotaxis behavior in the OTT. Furthermore, ARS also induced oxidative damage by increasing TBARS and decreasing NPSH levels. ARS-induced behavioral and biochemical effects were not blocked by any curcumin preparation. Therefore, we suppose that curcumin does not have anti-stress effects on the ARS in zebrafish.

neuroscience↗

bioRxiv2021

Curcumin micronization by supercritical fluid: in vitro and in vivo biological relevance

Curcumin, a polyphenol extracted from the rhizome of Curcuma longa L. (Zingiberaceae), is shown to have antioxidant, anti-inflammatory, neuroprotective, anxiolytic, and antidepressant properties in both preclinical and clinical studies. However, its low bioavailability is a limitation for its potential adoption as a therapeutic agent. The process of micronization can overcome this barrier by reducing the particle size and increasing the dissolution rate, potentially improving the bioavailability of the compounds of interest. In this study, we compared the in vitro antioxidant effects of curcumin (CUR) and micronized curcumin (MC) and studied their effects on behavioral and neurochemical parameters in zebrafish submitted to unpredictable chronic stress (UCS). MC (1 g/L) presented higher antioxidant activity in vitro as compared to CUR, as measured by iron-reducing antioxidant power (FRAP), 1,1-diphenyl-2-2-picyryl-hydrazyl radical removal (DPPH), and deoxyribose tests. UCS increased total distance traveled in the social interaction test (SI), while decreased crossings, time, and entries to the top area in the novel tank test (NTT). No effects of UCS were observed in the open tank test (OTT). The behavioral effects induced by UCS were not blocked by any curcumin preparation. UCS also decreased non-protein thiols (NPSH) levels, while increased glutathione reductase (GR) activity and thiobarbituric acid reactive substances (TBARS) levels on zebrafish brain. MC presented superior antioxidant properties than CUR in vivo, blocking the stress-induced neurochemical effects. Although this study did not measure the concentration of curcumin on the zebrafish brain, our results suggest that micronization increases the bioavailability of curcumin, potentiating its antioxidant activity both in vitro and in vivo. Our study also demonstrates that counteracting the oxidative imbalance induced by UCS is not sufficient to block its behavioral effects.

neuroscience↗

bioRxiv2021

Anti-stress effects of the glucagon-like peptide-1 receptor agonist liraglutide in zebrafish

Stress-related disorders are extremely harmful and cause significant impacts on the individual and society. Despite the limited evidence regarding glucagon-like peptide-1 receptor (GLP-1R) and mental disorders, a few clinical and preclinical studies suggest that modulating this system could improve symptoms of stress-related disorders. This study aimed to investigate the effects of liraglutide, a GLP-1R agonist, on neurobehavioral phenotypes and brain oxidative status in adult zebrafish. Acute liraglutide promoted anxiolytic-like effects in the light/dark test, while chronic treatment blocked the impact of unpredictable chronic stress on behavioral and physiological parameters. Taken together, our study demonstrates that liraglutide is active on zebrafish brain and may counteract some of the effects induced by stress. More studies are warranted to further elucidate the potential of GLP-1R agonists for the management of brain disorders.

pharmacology and toxicology↗

bioRxiv2020

How do zebrafish respond to MK-801 and amphetamine? Relevance for assessing schizophrenia-relevant endophenotypes in alternative model organisms

Background and PurposeSchizophrenia pathophysiology has been associated with dopaminergic hyperactivity, loss of parvalbumin-positive GABAergic interneurons, NMDA receptor hypofunction, and redox dysregulation. Most behavioral assays and animal models to study this condition were developed in rodents, leaving room for species-specific biases that could be avoided by cross-species approaches. As MK-801 and amphetamine are largely used in mice and rats to mimic schizophrenia features, this study aimed to investigate the effects of these drugs in zebrafish. Experimental ApproachAdult zebrafish were exposed to MK-801 (1, 5, and 10 M) or amphetamine (0.625, 2.5, and 10 mg{middle dot}L-1) and observed in paradigms of locomotor activity and social behavior. Oxidative parameters relevant to schizophrenia were quantified in brain tissue. Key ResultsMK-801 disrupted social interaction, an effect that resembles the negative symptoms of schizophrenia. It also altered locomotion in a context-dependent manner, with hyperactivity when fish were tested in the presence of social cues and hypoactivity when tested alone. On the other hand, exposure to amphetamine was devoid of effects on locomotion and social behavior, while increased lipid peroxidation in the brain. Conclusion and ImplicationsKey outcomes induced by MK-801 in rodents were replicated in zebrafish, which suggests this species is suitable as an alternative model animal to study psychotic disorders. More studies are necessary to further develop preclinical paradigms with this species and ultimately optimize the screening of potential novel treatments.

neuroscience↗