The utility of genetics for predicting alcoholism and alcohol-related disorders islimited given environmental variance and a finite understanding of all geneticcontributors. This has led to interest in phenotypic markers that can be used forclassifying individuals at heightened risk for developing alcoholism and alcohol-relateddisorders. One such marker is the P300, an event-related potential (ERP) observed tohave an attenuated amplitude and increased latency in both humans and animals whohave a genetic predisposition to alcohol use. To study the utility of the P300 as abiomarker for alcohol use disorders (AUDs), we examined its characteristic in alcoholpreferring (P) and non-preferring (NP) rats naïve to alcohol using an auditory oddballtask. Electroencephalography (EEG) was measured using a novel, noninvasive methodafter rats were trained to press a lever for food in response to the rare “target” tone, butnot after the more frequent “standard” tone. The amplitude of the N2-P3 complexrevealed a significant line x tone interaction (F(1,37)=4.365, p=.044, η2p=.106). Post-hoc analysis revealed an approaching significant attenuation in the N2-P3 amplitude for the P(versus NP) rats only for the target tone (p=.077, η2p= .078). These results support theprevious findings reporting a decrease in P300 amplitude in those with a geneticpredisposition to alcohol and adds support to the utility of the P300 as a endophenotypicmarker of alcoholism
