title: Long-term exposure to paraquat alters behavioral parameters and dopamine levels in adult zebrafish (Danio rerio).
abstract: Chronic exposure to paraquat (Pq), a toxic herbicide, can result in Parkinsonian symptoms. This study evaluated the effect of the systemic administration of Pq on locomotion, learning and memory, social interaction, tyrosine hydroxylase (TH) expression, dopamine and 3,4-dihydroxyphenylacetic acid (DOPAC) levels, and dopamine transporter (DAT) gene expression in zebrafish. Adult zebrafish received an i.p. injection of either 10 mg/kg (Pq10) or 20 mg/kg (Pq20) of Pq every 3 days for a total of six injections. Locomotion and distance traveled decreased at 24 h after each injection in both treatment doses. In addition, both Pq10- and Pq20-treated animals exhibited differential effects on the absolute turn angle. Nonmotor behaviors were also evaluated, and no changes were observed in anxiety-related behaviors or social interactions in Pq-treated zebrafish. However, Pq-treated animals demonstrated impaired acquisition and consolidation of spatial memory in the Y-maze task. Interestingly, dopamine levels increased while DOPAC levels decreased in the zebrafish brain after both treatments. However, DAT expression decreased in the Pq10-treated group, and there was no change in the Pq20-treated group. The amount of TH protein showed no significant difference in the treated group. Our study establishes a new model to study Parkinson-associated symptoms in zebrafish that have been chronically treated with Pq.
authors.affiliation: 1 Programa de Pós-Graduação em Biologia Celular e Molecular, Laboratório de Neuroquímica e Psicofarmacologia, Faculdade de Biociências, Pontifícia Universidade Católica do Rio Grande do Sul , Porto Alegre, Brazil .
authors.forename: Josiane W
authors.initials: JW
authors.lastname: Bortolotto
authors.forename: Giana P
authors.initials: GP
authors.lastname: Cognato
authors.forename: Raissa R
authors.initials: RR
authors.lastname: Christoff
authors.forename: Laura N
authors.initials: LN
authors.lastname: Roesler
authors.forename: Carlos E
authors.initials: CE
authors.lastname: Leite
authors.forename: Luiza W
authors.initials: LW
authors.lastname: Kist
authors.forename: Mauricio R
authors.initials: MR
authors.lastname: Bogo
authors.forename: Monica R
authors.initials: MR
authors.lastname: Vianna
authors.forename: Carla D
authors.initials: CD
authors.lastname: Bonan
mesh_terms: D015102:3,4-Dihydroxyphenylacetic Acid / Q000378:metabolism; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D004298:Dopamine / Q000378:metabolism*; D050483:Dopamine Plasma Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism; D029941:Fish Proteins / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects*; D006540:Herbicides / Q000633:toxicity*; D010269:Paraquat / Q000633:toxicity*; D016133:Polymerase Chain Reaction; D014446:Tyrosine 3-Monooxygenase / Q000235:genetics / Q000378:metabolism; D015027:Zebrafish / Q000235:genetics / Q000502:physiology*; D029961:Zebrafish Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D050483:Dopamine Plasma Membrane Transport Proteins; D029941:Fish Proteins; D006540:Herbicides; C546868:SLC6A3 protein, zebrafish; D029961:Zebrafish Proteins; D015102:3,4-Dihydroxyphenylacetic Acid; D014446:Tyrosine 3-Monooxygenase; D010269:Paraquat; D004298:Dopamine