The neurophysiological effects of iron in early life stages of zebrafish. (December 2020)

• Record Type: Journal Article
• Authors: Hassan, Ayaat T.; Kwong, Raymond W.M.
• Is Part Of: Environmental pollution. Volume 267(2020)
• Publication Date: 2020-12
• Subjects: Iron -- Neurophysiology -- Neurotoxicity -- Metal homeostasis -- Zebrafish; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2020.115625
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: Trace metal/ion homeostasis, neurophysiological performance, and molecular responses to iron (Fe) exposure were investigated in the model organism zebrafish ( Danio rerio ). The findings demonstrated that exposure to a sublethal concentration of ferric iron (Fe 3+ ) increased Fe contents in both the whole body and head region of developing zebrafish. Among the various trace metals and major ion examined, a dysregulation in manganese, zinc, nickel, and calcium balance was also observed in Fe-exposed larvae. Further biochemical assay and in-vivo imaging revealed that Fe exposure resulted in possible oxidative stress-induced damage, and an increased generation of reactive oxygen species in specific regions of the larvae. Using a droplet digital PCR (ddPCR) technology, it was found that the expression levels of various oxidative stress-responsive genes were temporally modulated by Fe exposure. Additionally, Fe-exposed larvae exhibited an impairment in escape response and a decrease in swimming activity. These larvae also appeared to exhibit a reduced anxiety-like behaviour. Together, our research suggested that larvae experiencing an increased Fe loading exhibited a dysregulation in metal homeostasis and a decrease in neurophysiological performance. These results suggested that neurophysiological assessments are sensitive methods to evaluate Fe toxicity in developing fish. Graphical abstract: Image 1 Highlights: Developing zebrafish are sensitive to sublethal level of Fe. Fe exposure disrupts metal homeostasis and induces oxidative stress responses. Fe exposure impairs the neurobehavioral performance of larvae.