es7b03937_si_001.pdf (474.58 kB)
Chronic Dietary Selenomethionine Exposure Induces Oxidative Stress, Dopaminergic Dysfunction, and Cognitive Impairment in Adult Zebrafish (Danio rerio)
journal contribution
posted on 2017-10-05, 00:00 authored by Mohammad Naderi, Arash Salahinejad, Ankur Jamwal, Douglas P. Chivers, Som NiyogiThe present study was designed to
investigate the effects of chronic
dietary exposure to selenium (Se) on zebrafish cognition and also
to elucidate possible mechanism(s) by which Se exerts its neurotoxicity.
To this end, adult zebrafish were exposed to different concentrations
of dietary l-selenomethionine (control, 2.3, 9.7, 32.5, or
57.7 μg Se/g dry weight) for 30 days. Cognitive performance
of fish was tested using a latent learning paradigm in a complex maze.
In addition, we also evaluated oxidative stress biomarkers and the
expression of genes involved in dopaminergic neurotransmission in
the zebrafish brain. Fish treated with higher dietary Se doses (32.5
and 57.5 μg Se/g) exhibited impaired performance in the latent
learning task. The impaired learning was associated with the induction
of oxidative stress and altered mRNA expression of dopamine receptors,
tyrosine hydroxylase, and dopamine transporter genes in the zebrafish
brain. Collectively, our results illustrate that cognitive impairment
in zebrafish could be associated with Se-induced oxidative stress
and altered dopaminergic neurotransmission in the brain.