Author(s): Hayoung Kim
Mentor(s): Anne Gibson
Institution Westminster
Nicotine and ethanol are the two most-commonly abused substances in the U.S.. However, effective treatments for these drugs are still not found, and the interdependence between these two drugs are not well publicized. This study investigates how ethanol exposure influences nicotine preference in C. elegans using a chemotaxis preference assay. We hypothesized that ethanol exposure would increase nicotine preference. One group of C. elegans was exposed to ethanol for 30 minutes at the L1 stage (3 days from birth), while another group experienced 300mM ethanol exposure from birth until the L1 stage. These groups helped determine if nicotine preference was dependent on the duration of ethanol exposure. Post-ethanol treatment, C. elegans were placed in a preference assay with nicotine (4 µL) in one zone and water (4 µL) in another in a 6-well plate. Each pair of 6-well plates had different concentrations of nicotine, from 0 mM, 15 mM, 30 mM to 50mM (total of eight 6-well plates), to see if nicotine concentration influenced the preference index. Imaging occurred after 30 minutes of exposure to testing zone to calculate the preference index: (# of C. elegans in the nicotine zone)/(# in both zones). A two-way ANOVA assessed the effect of ethanol on nicotine preference. A 30-minute ethanol exposure showed no significant difference in nicotine preference, whereas lifelong exposure resulted in an increasing trend of nicotine preference at low dosages (~30 mM). These results suggest further experiments are needed to refine the data. This study aims to expand the body of knowledge between ethanol and nicotine addiction, and contribute to better treatment strategies.