Considerable progress has been made to develop mouse and rat models that simulate several relevant human endophenotypic behavioral traits associated with alcohol-related problems. Our initial electrophysiological studies found that ERP responses that distinguish high-alcohol preferring B6 mice from low-alcohol preferring D2 mice (decreased N1 and P3 amplitudes) differ from the ERP responses that distinguish HAP-1 from LAP-1 mice (increased P1 amplitude) (Ehlers and Somes, 2002, Slawecki et al., 2003). The present study extended our initial analyses in these genetic mouse models and found that the decrease in P3 amplitudes previously shown in B6 mice, compared to D2 mice, is related to reductions in evoked delta ERO energy and delta and theta phase locking. We found no evidence supporting our hypothesis that reductions in theta ERO energy are associated with reduced P3 amplitudes in B6 and D2 mice. Our data also suggest that the increase in P1 amplitudes reported in HAP-1 mice, compared to LAP mice, is associated with increases in evoked theta ERO energy, not in alpha/beta ERO energy. These studies suggest that differences in delta and theta ERO measures
