Genetic variations in the CHRNA7 gene, or the altered expression and function of α7 nAChR have been associated with AD [41,160,171,172] and PD [173,174], and in the case of AD, the reduced α7 expression is correlated with beta-amyloid (Aβ) plaque deposition and cognitive impairments [41,160,175]. This evidence concerns the gene CHRNA7 and Alzheimer disease.