Using Zebrafish as a Model for Investigating the Neuropathophysiology of Iron Overload During Development

In this research, we used larval zebrafish (Danio rerio) to examine the effects of iron (Fe) exposure on neurophysiological performance and oxidative-stress responses during development. Our findings demonstrated that exposure to elevated Fe levels from 0 to 5 days post-fertilization (dpf) increased iron levels in the larvae. These Fe-exposed fish exhibited delays in touch-evoked escape response and decreased swimming activity, indicating impairments in sensory-motor function. Results from the reactive oxygen species (ROS) assay suggested that the impairment was likely associated with the increased ROS generation after iron exposure. mRNA expression levels of major iron transport genes (e.g., DMT1, IREG1) were not decreased by iron exposure until 5 dpf. Interestingly, the expression levels of various oxidative stress-responsive genes (e.g., SOD2, CAT, GST) were differentially modulated by iron exposure. Overall, our research suggested that exposure to elevated iron resulted in oxidative stress, which led to neurophysiological dysfunction in developing zebrafish.