It has been postulated that the development of tolerance to alcohol-induced effects is positively associated with a propensity to consume high levels of alcohol [e.g. (Koob et al. 1998); (Le, Mayer 1996)]. We found some support for this hypothesis in the animal literature, as it relates to motor impairment. High-drinking AA (Nikander, Pekkanen 1977;Le, Kiianmaa 1988;Rusi et al. 1977), HAD-1 (Suwaki et al. 2001), P (Rodd et al. 2004;Bell et al. 2001), and UChB (Tampier, Mardones 1999) rats have lower sensitivity and/or develop quicker tolerance to the motor impairing effects of alcohol than their low-drinking ANA, LAD-1, NP, and UChA counterparts. Contrary to this hypothesized association are the findings that HAD-2 rats do not differ from LAD-2 rats in this regard (Suwaki et al. 2001) and HARF rats display greater alcohol-induced motor impairment than LARF rats (Shram et al. 2004). In addition, findings with the selected HAP and LAP mouse lines did not support the hypothesis, with the observation that these lines did not differ in initial sensitivity or the development of tolerance to alcohol-induced motor ataxia (Grahame et al.
