Another commonly used type of animal model involves selectively bred lines. Starting in the late 1940s, researchers in Chile bred rats that preferred to drink alcohol-containing solutions as well as rats that avoided alcohol (Mardones and Segovia-Riquelme 1983). Such selective breeding has been repeated numerous times with rats and mice, resulting in pairs of animal lines that differ with respect to a particular alcohol-related trait. A list of currently available rodent selected lines is shown in table 1. Studies with the high- and low-drinking selected lines in particular have been a major focus of NIAAA-sponsored research efforts (for a review, see Crabbe et al. 2010; other reviews were published in a special issue of Addiction Biology, Vol. 11[3–4], 2006). Animals have been selected for many alcohol-related traits, including preference for alcohol, tolerance or sensitivity to alcohol’s effects, and withdrawal severity. New selection projects also are emerging; for example, researchers are breeding mice that exhibit binge-like drinking (Crabbe et al. 2009).
