Zinc nanoparticles induced brain lesions and behavioral changes in two tilapia species

In this study, we investigated the induced behavioral changes and neuropathology of prolonged exposure to high doses of Zn-NPs in two species of tilapia, T. nilotica and T. zilli. Fish that were treated with 2000 µg Zn-NPs /L showed severe degenerative changes and vacuolation in the neuropil, particularly of the optic tectum, with congestion of the blood vessels of both the cerebral cortex and the meninx primitive. Loss of the Purkinje cell layer of the cerebellum was noticed as well. Fish showed behavioral changes that included loss of equilibrium, slower movement and swimming sideways. No significant differences were observed between T. nilotica and T. zilli in behavioral or pathological changes. Our results highlight the Zn-NPs neurotoxicity and its accompanied neuropathology and related behavioral changes in fish. More caution is needed during the usage of Zn-NPs to avoid possible deleterious impacts on human and animal health.