is also a full agonist of α7 and a partial agonist of α3β4* receptors, which have been shown to display higher efficacy (maximal release) than α4β2* receptors (Mihalak et al. 2006). Moreover, the antidepressant Bupropion, which alters brain reward circuits influenced by nicotine and is used as an anti-tobacco agent, has been shown to act as a nAChR antagonist, including the α3β4* subtypes (Fryer and Lukas 1999; Slemmer et al. 2000; Cheverud 2001, 2007; Mansvelder et al. 2007). The role of α3β4* nAChRs in the habenula and interpeduncular nucleus has been studied using an alkaloid, ibogaine, and its derivative, 18-Methoxycoronaridine (MC-18) (Glick et al. 2001). Importantly, in rodents, MC-18 leads to decreased self-administration not only of nicotine and alcohol, but also of morphine, cocaine and methamphetamine (Maisonneuve and Glick 2003). Thus, there is evidence from animal models that these particular subunits, and their corresponding genes, are likely to be involved in multiple substance-related behaviors, including behaviors related to substances other than nicotine and alcohol.
