Alcohol and tobacco addiction are among the highest causes of preventable death worldwide (Mokdad et al., 2004) and the comorbidity of these two substance abuse disorders is striking (DiFranza and Guerrera, 1990; Batel et al., 1995; Falk et al., 2006). While the easy availability and low social stigma of alcohol and cigarettes provides an explanation of their high prevalence of dual dependence, strong neurobiological evidence suggests a common link between these two substances (de Fiebre et al., 1990; Smith et al., 1999; Gould et al., 2001; Marubio et al., 2003; Tizabi et al., 2007). Neuronal nicotinic acetylcholine receptors (nAChRs) are widely expressed throughout the brain (Gotti et al., 2007) and are suggested to be the common biological target of nicotine and ethanol (Tapper et al., 2004; Funk et al., 2006; Steensland et al., 2007; Bito-Onon et al., 2011). nAChRs are pentameric ligand-gated ion channels, consisting of various heteromeric or homomeric combinations of α (α2–α10) and β (β2–β4) subunits (Albuquerque et al., 2009; Gotti et al., 2009). Most neuronal nAChRs are heteromeric receptors with just two binding sites, but some subunits,
