Motor effects of rotenone in zebrafish as an animal model of Parkinson-like disease

Abstract

Objective: Analyze the induction of Parkinson-like disease symptoms in zebrafish by rotenone exposure. Methods: This is an experimental study conducted on adult zebrafish divided into three different groups, a control group exposed to 1% (v/v) DMSO and two groups exposed to 2 and 5 µg/L of rotenone for 28 consecutive days. The locomotor activity of the animals was evaluated in the following parameters: total distance, average speed, and stopped time. Non-motor parameters were evaluated in the light/dark preference test to observe behavioral changes. Results: Significant reductions between the groups exposed to rotenone (2 and 5 µg/L) compared to the control group were observed in the parameters of the total distance (14.97 and 18.84%), mean speed (15.05 and 18.39%), and the number of crossed lines (15.74 and 21.96%). An increase in downtime of 82.15% was observed only in the group exposed to 5 µg/L of rotenone. Changes in light/dark preference were not observed. The mortality rate was 15 and 35% for the 2 and 5 µg/L rotenone groups, respectively. Conclusion: The rotenone concentrations studied were able to produce negative effects on the locomotor activity of fish, causing Parkinson-like disease motor symptoms.