CHRNA7 and early-onset autosomal dominant Alzheimer disease: For example, during early stages of Alzheimer's disease, α7 nAChRs are upregulated in response to chronic exposure to amyloid-β1-42 (Aβ), which may contribute to hyperexcitability (Liu et al. 2013; Dineley et al. 2002; Rennie 2025).