CHRNA7 and Alzheimer disease: Interestingly, exposure of cultured rat primary astrocytes to aggregated Aβ1–42 (0.1–100 nM, but not 1 μM) for 48 h resulted in elevated α7nAChR mRNA and protein levels [235] suggesting the increased expression of α7nAChR in astrocytes in the AD brain may be a response to Aβ exposure.