CHRNA4 and Alzheimer disease: For example, nicotine and other nAChR agonists with differential subtype selectivity have been identified as potential cognition-enhancing therapeutic drugs, particularly for the treatment of Alzheimer’s disease (AD) (Bencherif and Schmitt 2002; Buccafusco 2004; Levin 2002; Moaddel et al. 2007; Picciotto and Zoli 2002).