2010). For example, it has been shown that allopregnanolone, while not altering the overall amount of ethanol consumed, at moderate to high doses reduced licking frequency and high doses reduced bout sizes in mice (Ford et al., 2008). Several of the examples in the text of Section 5 highlight differences in pharmacological efficacy across self-administration procedures (i.e., acquisition vs. maintenance vs. relapse of self-administration behavior) highlighting that very few studies have examined differences in treatment efficacy within the same subject (Table 4). A recent study not only examined pharmacological efficacy across high alcohol-consuming rat lines and test procedures but also employed multiple high resolution behavioral endpoints (Maccioni et al., in press). As noted in Section 6.4. below, this study (Maccioni et al., in press) found that GS39783, and to some extent baclofen, differentially affected – from almost no effect to virtually complete suppression – lever-responding for alcohol in P, sP, and AA rats (Maccioni et al., in press). These latter findings provide support for (a) heterogeneity in the efficacy of pharmacological manipulations on alcohol self-administration by different alcohol-preferring rat lines, (b) the hypothesis that these rats lines may represent models of different subtypes of alcoholics, and (c) the need for
