Assessment of neurobehavioral parameters in zebrafish larvae in a rotenone-induced Parkinson’s-like disease model

The development of animal models that mimic the behavioral and symptomatic aspects of Parkinson’s Disease (PD) is essential for advancing new therapies. This study aimed to assessment of neurobehavioral parameters in zebrafish larvae in a rotenone-induced Parkinson’s-like disease model. Zebrafish larvae at 72 hours post-fertilization, when dopaminergic projections are fully developed, were exposed to rotenone (RT: 5.00–15.00 µg/L), a compound known to selectively damage dopaminergic neurons, thus inducing PD-like symptoms. Levodopa treatment was also evaluated. Survival and neurobehavioral endpoints were evaluated using a series of tests: thigmotaxis, touch sensitivity, optomotor response (OMR), and bouncing balls. Larval survival significantly decreased at RT concentrations above 12.00 µg/L. Thigmotaxis and touch sensitivity were impaired at concentrations greater than 11.00 µg/L. In the OMR test, all measured parameters showed significant changes from 10.00 µg/L onward. Similarly, RT at concentrations above 10.00 µg/L reduced permanence in the non-stimulated area, while the clustering response of larvae was notably affected starting at 11.00 µg/L. These findings demonstrate that RT exposure induces specific and measurable neurobehavioral alterations in zebrafish larvae. The neurobehavioral parameters in this study is both detailed and reproducible, providing a valuable tool for future research and the screening of potential therapeutic compounds targeting Parkinson’s Disease.