Electrophysiological differences between the rat lines have also been demonstrated (Breen and Morzorati, 1996; Ehlers et al., 1991, 1992, 1999; Morzorati et al., 1994; Robledo et al., 1993, 1994). The study of neurophysiological endophenotypes in P and NP rats with well-differentiated ethanol-related phenotypes could be an additional tool for identifying susceptibility genes for ethanol dependence. We have previously characterized the electrophysiological profile of P and NP rats and found that P rats have significantly lower amplitude of the P3 component of the event-related potential (ERP), when compared to NP rats (Ehlers et al., 1999). This finding is similar to what has been reported for human subjects at differing risk for ethanol dependence (for review, see Porjesz et al., 2005).
