Mercury Levels in the Worldwide Farmed Fish: A Systematic Review.

Aquaculture, specifically farmed fish, contributes to global aquatic fish stuff production. The present study systematically reviewed mercury levels in farmed fish. One hundred two scientific articles were found in four databases.

Baseline polycyclic aromatic hydrocarbon maternal transfer data in Lesser Numbfish Narcine brasiliensis (Elasmobranchii: Batoidea) from an impacted estuary in Southeastern Brazil.

Maternal offloading of polycyclic aromatic hydrocarbons (PAHs) poses a significant exposure route for developing embryos, with implications for subsequent generations. Despite known developmental effects regarding fish physiology and behavior, maternal PAH transfer assessments in elasmobranchii are still lacking. This study investigated PAH contamination and maternal transfer in one female Lesser Numbfish (Narcine brasiliensis) electric ray and seven embryos for the first time.

Human health risks assessment of the fluctuations in mercury levels in seafood from different key regions of Rio de Janeiro, Brazil.

Mercury (Hg) contamination on the Brazilian southeast coast has been highlighted, especially in relation to species of commercial importance. This study aimed to quantify the Hg concentration in species of mussels, fish, and crabs obtained from fishing colonies on the beaches of the west and south of the city of Rio de Janeiro, investigate the possible effect of seasonality, sex, and location sampling, and finally, the risk to consumer health in four different age groups. The difference between cooked and raw commercially available mussel samples was also verified.

Levels of Total Mercury and Health Risk Assessment of Consuming Freshwater Stingrays (Chondrichthyes: Potamotrygoninae) of the Brazilian Amazon.

Mercury is an element with potential risk to fish and those who consume it. Thus, this study aimed to determine the levels of total mercury (THg), carry out a health risk assessment related to the consumption of the freshwater stingrays , and determine the physical and chemical properties of the water where stingrays occur. Stingrays of the species were obtained from the Amazon River, and samples of the animals' musculature were collected to determine THg levels.

A systematic review on polycyclic aromatic hydrocarbon contamination in elasmobranchs and associated human health risks.

Polycyclic aromatic hydrocarbon (PAH) contamination is ubiquitous and comprises a significant worldwide concern in ecological and Public Health frameworks. Many aquatic biota representatives have been reported as contaminated by these toxic compounds, including one of the most threatened vertebrate groups, elasmobranchs (sharks and rays). Although elasmobranchs play important ecological roles and provide significant ecosystem services, they are highly consumed and comprise a cheap source of protein for humans globally.

Mercury contamination in seafood from an aquatic environment impacted by anthropic activity: seasonality and human health risk.

Petroleum activity and the dumping of domestic and industrial sewage are important sources of mercury (Hg) contamination in the aquatic environment. Thus, this article aimed to biomonitor the Hg concentration in fish, mussels, and swimming crabs of commercial importance in southeastern Brazil. The quantifications were carried out over a year to verify the influence of seasonality.

Social and asocial learning in zebrafish are encoded by a shared brain network that is differentially modulated by local activation.

Group living animals use social and asocial cues to predict the presence of reward or punishment in the environment through associative learning. The degree to which social and asocial learning share the same mechanisms is still a matter of debate. We have used a classical conditioning paradigm in zebrafish, in which a social (fish image) or an asocial (circle image) conditioned stimulus (CS) have been paired with an unconditioned stimulus (US=food), and we have used the expression of the immediate early gene c-fos to map the neural circuits associated with each learning type.

Food safety concerns on polycyclic aromatic hydrocarbon contamination in fish products from estuarine bays throughout the American continent.

Estuarine environments are highly productive ecosystems exhibiting high fish biodiversity and richness. Estuarine bays yield significant fisheries catches, making them the target of extractive activities by both artisanal and industrial fisheries. These areas, however, are highly vulnerable to chemical contamination, such as polycyclic aromatic hydrocarbons (PAH) associated with oil spills and other anthropogenic activities, which can jeopardize animal health and consumer welfare.

The Role of the Ecotoxicology Applied to Seafood as a Tool for Human Health Risk Assessments Concerning Polycyclic Aromatic Hydrocarbons.

Background: Polycyclic aromatic hydrocarbons (PAHs) are persistent pollutants routinely detected in aquatic ecosystems. It is, therefore, necessary to assess the link between deleterious marine biota PAH effects, especially in commercialized and consumed animals, environmental health status, and potential human health risks originating from the consumption of contaminated seafood products. Thus, this review seeks to verify the relationships of ecotoxicological studies in determining effect and safety concentrations on animals routinely consumed by humans.

Innate chemical, but not visual, threat cues have been co-opted as unconditioned stimulus for social fear learning in zebrafish.

Animals can use social information to detect threat in the environment. In particular, social learning allows animals to learn about dangers without incurring in the costs of trial-and-error learning. In zebrafish, both chemical and visual social cues elicit an innate alarm response, which consists of erratic movement followed by freezing behavior.

Actin remodeling, the synaptic tag and the maintenance of synaptic plasticity.

Activity-dependent plasticity of synaptic connections is a hallmark of the mammalian brain and represents a key mechanism for rewiring neural circuits during development, experience-dependent plasticity, and brain disorders. Cellular models of memory, such as long-term potentiation and long-term depression, share common principles to memory consolidation. As for memory, the maintenance of synaptic plasticity is dependent on the synthesis of de novo protein synthesis.

Enhanced LTP in aged rats: Detrimental or compensatory?

Age-dependent memory deterioration has been well documented and yet an increase in rat hippocampal LTP upon aging has been reported. This poses the question of whether the enhanced LTP is a cause or an attempt to compensate the memory deficits described in aged rats. Hippocampal slices from young, adult and aged Wistar rats were pre-incubated, with an NMDA receptor (NMDAR) antagonist, memantine (1 μM, 4 h), and hippocampal LTP was evaluated.