Photoaged microplastics induce neurotoxicity via oxidative stress and abnormal neurotransmission in zebrafish larvae (Danio rerio)

The effects of environmental changes on the endocrine regulation of feeding in fishes

“…For example, MPs reduce digestive enzymes and cause hepatic dysfunction in Nothobranchius guentheri [ 119] , and induce tissue damage in the intestine of Girella laevifrons [120] and in liver and intestine of European sea bass [121] and goldfish larvae [122], thus impairing digestive performance. In zebrafish, exposure to MPs inhibits locomotion and increases neurotransmitter (5-HT, GABA, DA and acetylcholine) levels [123], downregulates the insulin receptor, and increases cortisol levels suggesting a dysregulation of metabolism, in particular glucose metabolism [124]. In adult marine medaka ( Oryzias melastigma ), exposure to MPs induce changes in the gut microbiota and a decrease in adipocyte leptin receptor mRNA expression levels [125], suggesting modifications in metabolism (and perhaps feeding).…”

Temperature- and chemical-induced neurotoxicity in zebrafish

“…In zebrafish, the impact of neurotoxic substances on oxidative stress can be studied by analysing the expression and the activity of these enzymes or other markers related to the oxidative stress ( Figure 2 ). For instance, neurotoxicity studies in zebrafish have analysed the gene expression of sod1 ( Powers et al, 2017 ; Cao et al, 2019 ; Ding et al, 2023 ; Zhu et al, 2023 ), sod2 ( Sarasamma et al, 2018 ; Cao et al, 2019 ; Wu et al, 2021 ; Ji et al, 2021 ; Patel et al, 2021 ; Haridevamuthu et al, 2022 ; Orozco-Hernandez et al, 2022 ), cat ( Gu et al, 2021 ; Ji et al, 2021 ; Haridevamuthu et al, 2022 ; Orozco-Hernandez et al, 2022 ; Kachot and Patel, 2023 ; Zhu et al, 2023 ) and gpx ( gpx1a and gpx4a ) ( Ji et al, 2021 ; Haridevamuthu et al, 2022 ; Orozco-Hernandez et al, 2022 ; Ding et al, 2023 ), gst ( Haridevamuthu et al, 2022 ), gsr ( Haridevamuthu et al, 2022 ), gclm ( Wu et al, 2021 ; Ji et al, 2021 ; Chian et al, 2022 ) and gsto2 ( Ji et al, 2021 ). For example, reduced sod expression was observed following treatment with cadmium chloride ( Pan et al, 2018 ), zinc chloride ( Sarasamma et al, 2018 ), mercury chloride ( Patel et al, 2021 ), fipronil ( Wu et al, 2021 ), acrylamide ( Haridevamuthu et al, 2022 ), while lead ( Ji et al, 2021 ) and fluoxetine ( Orozco-Hernandez et al, 2022 ) led to an increase in sod expression.…”

“…For example, reduced sod expression was observed following treatment with cadmium chloride ( Pan et al, 2018 ), zinc chloride ( Sarasamma et al, 2018 ), mercury chloride ( Patel et al, 2021 ), fipronil ( Wu et al, 2021 ), acrylamide ( Haridevamuthu et al, 2022 ), while lead ( Ji et al, 2021 ) and fluoxetine ( Orozco-Hernandez et al, 2022 ) led to an increase in sod expression. Additionally, enzyme activity analysis indicated a decrease in sod activity following treatment with photoaged polystyrene ( Ding et al, 2023 ), bisphenol A ( Gu et al, 2021 ), acrylamide ( Haridevamuthu et al, 2022 ), and AlCl3 ( Haridevamuthu et al, 2023 ). Conversely, other neurotoxicity studies reported an increase in sod activity following treatment with venlafaxine ( Alves et al, 2023 ), phenytoin ( Cardoso-Vera et al, 2022 ), and lincomycin hydrochloride ( Cheng et al, 2020 ).…”

“…The neurotoxic effects on the GABAergic system are typically investigated in zebrafish by analysing the expression of genes associated with the GABAergic pathway, such as GABA synthesizers [ gad1b ( Cheng et al, 2020 ; Shi et al, 2022 ; Yu et al, 2022 ; Ding et al, 2023 ; Xiang et al, 2023 ) and gad2 ( Ding et al, 2023 )], receptors ( gabra1 ( Shi et al, 2022 ; Liu et al, 2023 ; Ding et al, 2023 ), gabra6a ( Atzei et al, 2021 ), gabra6b ( Liu et al, 2023 ), gabrb3 ( Luo et al, 2023 ), gabrg2 ( Ding et al, 2023 ; Xiang et al, 2023 )), and transporters ( gat1 ( Cheng et al, 2020 ; Ding et al, 2023 ; Xiang et al, 2023 ), gat3 , vgat ). For example, exposure to lead has been shown to increase gad1b and gad2 expression and modulate the expression of gabra1 , gabbr1a , gat1 , gat3 , vgat expression ( Wirbisky et al, 2014 ) ( Supplementary Table S2 ).…”

“…The impact on the dopaminergic system can be investigated by analysing the morphology of dopaminergic neurons ( Cui et al, 2013 ; Yao et al, 2017 ; Jin et al, 2019a ; Wang et al, 2019 ), aided by the availability of zebrafish transgenic lines with GFP-labelled dopaminergic neurons. Analysis of dopamine levels ( Wang et al, 2015 ; Sheng et al, 2016 ; Soares et al, 2017 ; Wang et al, 2019 ; Han et al, 2021 ; Yang et al, 2022 ) and its metabolite, hydroxy-phenyl acetic acid, along with the expression of dopamine transporter ( dat ) genes ( Ji et al, 2021 ; Gyimah et al, 2022 ), dopamine receptors ( drd1b ( Li et al, 2019 ; Tran et al, 2021 ; Hong et al, 2022 ; Liu et al, 2023 ), drd2a ( Cao et al, 2019 ; Gyimah et al, 2022 ; Shi et al, 2022 ; Liu et al, 2023 ; Ding et al, 2023 ; Mahapatra et al, 2023 ; Torres-Ruiz et al, 2023 ; Xiang et al, 2023 ), drd2b [ Shi et al, 2022 ; Liu et al, 2023 ; Torres-Ruiz et al, 2023 )] and developmental genes correlated to dopamine such as manf ( Li et al, 2018 ; Qian et al, 2018 ; Li et al, 2020 ; Zhu et al, 2020 ; Tian et al, 2021 ; Hong et al, 2022 ; Heredia-García et al, 2023 ; Shi et al, 2023 ), otpa , otpb ( Wang et al, 2019 ), wnt1 ( Ho et al, 2013 ), wnt5b ( Ho et al, 2013 ), wnt10b ( Xu et al, 2022a ), wnt4a ( Xu et al, 2022a ), wnt3a , wnt5a ( Wang et al, 2019 ) can be analysed ( Supplementary Table S2 ). Treatment with lead in zebrafish larvae significantly reduced the number of dopaminergic neurons in the midbrain ( Jin et al, 2019b ).…”