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 (Fe³⁺) 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.

在模型生物斑马鱼（Danio rerio）中研究了痕量金属/离子稳态，神经生理性能以及对铁（Fe）暴露的分子响应。研究结果表明，暴露于亚致死浓度的三价铁（Fe ³⁺）增加了发育中的斑马鱼整个身体和头部的铁含量。在检查的各种痕量金属和主要离子中，在暴露于铁的幼虫中还观察到锰，锌，镍和钙平衡的失调。进一步的生化分析和体内成像显示，铁暴露可能导致氧化应激诱导的损害，并在幼虫的特定区域增加了活性氧的产生。使用液滴数字PCR（ddPCR）技术，发现各种氧化应激反应基因的表达水平受Fe暴露的影响。此外，铁暴露的幼虫表现出逃避反应的损害和游泳活动的减少。这些幼虫似乎也表现出减少的焦虑样行为。一起，我们的研究表明，Fe含量增加的幼虫表现出金属稳态失调和神经生理功能下降。这些结果表明，神经生理学评估是评估发育中鱼类铁毒性的灵敏方法。