Developmental iron exposure induces locomotor alterations in Drosophila: Exploring potential association with oxidative stress.

Prenatal iron (Fe) exposure has been associated with learning and cognitive impairments, which may be linked to oxidative stress resulting from elevated Fe levels and harm to the vulnerable brain. Drosophila melanogaster has contributed to our understanding of molecular mechanisms involved in neurological conditions. This study aims to explore Fe toxicity during D. melanogaster development, assessing oxidative stress and investigating behaviors in flies that are related to neurological conditions in humans. To achieve this goal, flies were exposed to Fe during the developmental period, and biochemical and behavioral analyses were conducted. The results indicated that 20 mM Fe decreased fly hatching by 50 %. At 15 mM, Fe exposure increased lipid peroxidation, and GSH levels decreased starting from 5 mM of Fe. Superoxide Dismutase activity was enhanced at 15 mM, while Glutathione S-Transferase activity was inhibited from 5 mM. Although chronic Fe exposure did not alter acetylcholinesterase (AChE) activity, flies exhibited reduced locomotion, increased grooming, and antisocial behavior from 5 mM of Fe. This research highlights potential Fe toxicity risks during development and underscores the utility of D. melanogaster in unraveling neurological disorders, emphasizing its relevance for future research.

Exposure to Mancozeb results in increased MAPK phosphorylation and locomotor deficits in zebrafish larvae.

Mancozeb is a widely used fungicide whose toxicity has been reported in non-target organisms, being considered to have high or very high acute toxicity to aquatic organisms. However, the toxicity of this compound is not well characterized in the developmental stages of fish. In this study, Danio rerio with 4-, 5-, and 6-days post fertilization (dpf) was exposed to MZ at non-lethal concentrations for 24, 48, or 72 h and subsequently, behavioral alterations, oxidative stress parameters and ERK, p38MAPK, and Akt phosphorylation were analyzed. MZ exposure during the larval period decreased motor performance evaluated by traveled distance, immobile time, and time spent in the peripheral area. In parallel, MZ induced ROS levels and increased the number of cells in apoptosis, causing severe DNA damage, inducing Acetylcholinesterase and Superoxide dismutase activities, and inhibiting Glutathione peroxidase and thioredoxin reductase. Additionally, phosphorylation levels of the proteins p38MAPK, ERK2, and Akt were stimulated. These findings are relevant considering the ecological implications of MZ exposure to fishes in different developmental stages and the role of the MAPK pathway in events like development and cell death.

Assessment of alcohol-induced aggressive behavior in zebrafish (Danio rerio): A practical class.

Ethanol (EtOH) is among the most consumed drugs in the world. The behavior of humans after ingestion of this drug is characteristic: At low doses it may be excitatory and at higher doses, it may induce depressant/sedative effects. Similar effects are observed in the zebrafish experimental model (Danio rerio), which has about 70% genetic similarity with humans and has been widely used in numerous research. With the objective of improving the learning of biochemistry students, this work aimed to develop a practical exercise in the laboratory for students to observe the behavioral repertoire of zebrafish under the effects of exposure to ethanol. Through this practical class, the students were able to observe the similarity of the behavior of the animal model with that of humans, showing its importance for the consolidation of knowledge, awakening in the students an interest in science and its applications in everyday life.