Parkinson's disease(PD) is a neurodegenerative disease that affects millions of individuals worldwide. There does not appear to be one simple cause of PD; rather, it likely develops from complex genetic and environmental interactions, which ultimately result in the loss of dopaminergic neurons in the substantia nigra.

Several studies have indicated that exposure to large-scale industrial pesticides, such as Paraquat and Maneb, is associated with increased risk of Parkinson's disease (Ritz, 2009). Additionally, research has been conducted on the link between increased exposure to Ziram in zebrafish embryos and neurodegeneration in their dopaminergic neurons (Lulla, 2016).

The purpose of this experiment is to determine if a phenylpyrazole pesticide, Fipronil, causes neurodegeneration in the motor neurons of Caenorhabditis elegans. If Fipronil increases the risk of Parkinson's disease, C. elegans exposed to a 0.001 mM Fipronil solution will exhibit more neurodegeneration in their motor neurons than C. elegans exposed to distilled water or to a solution of 0.2% Ethanol. Fipronil is commonly found in households (a common treatment for eradication of fleas on household pets), therefore people are more likely to be exposed to it than to Ziram or Paraquat, which are industrial pesticides.

For this experiment, wild type C. elegans will be grown on Nematode Growth Medium Petri dishes with K-12 E. coli. The nematodes will be age synchronized using a hypochlorite alkaline solution. They will be exposed to 0.001 mM Fipronil for 5 days, from when they hatch until two days after they reach maturity. Their motor neurons will be dyed using the fluorescent Dil and analyzed using the ImageJ software. The less fluorescent the neuron, the more neurodegeneration has occurred.

This study found that exposure to Fipronil causes a visible negative effect on the motor neurons of C. elegans. The mean Correct Total Cell Fluorescence value for neurons exposed to Fipronil was 9451807,544 photons, while the mean value for the nematodes exposed to 0.2% ethanol was 254164217.482 photons and 424568446.412 photons for the group exposed to distilled water. This signifies that Fipronil contributed on average to a loss of 40% of the total photons. The p-value corresponding to the F-statistic of one-way ANOVA is lower than 0.05, suggesting that the results from the three exposure groups are statistically significant.

Based on the change in neuron fluorescence of C. elegans exposed to Fipronil compared to the control groups, there is an indication that exposure to Fipronil causes degeneration of motor neurons. This signals that exposure to this pesticides can lead to an increased risk of developing Parkinson' disease.