In view of the evidence from human studies of the link between alcohol dependence and ERO energy (Porjesz et al., 2005), characterizing the relationship between an ethanol preference phenotype and changes in EROs, translating this information to an animal model may provide valuable information on the mechanisms underlying these measures. The present study extended our initial analyses of neurophysiological endophenotypes in P and NP rats to EROs generated in cortical sites in response to an auditory oddball paradigm (standard, rare and noise tones). In this study, we investigated oscillatory activity in the delta, theta, and alpha/beta frequency ranges in the parietal cortex of P and NP rats within the temporal window of the P3 ERP response. ERO and PL analyses were accomplished from the same datasets that were used to generate the ERP data reported in a previous publication (Ehlers et al., 1999). We hypothesize that differences in hippocampal P3 amplitudes previously reported in P and NP rats (Ehlers et al., 1999) are associated to differences in delta and theta ERO oscillatory activity.
