CHRNA7 and Cognitive impairment: In contrast, it appears that α7nAChR selective agonists (e.g., PHA-543613) and galantamine may ameliorate Aβ-impaired working and reference memory, suggesting that α7 nAChR activation reduces Aβ-induced cognitive deficits, whereas receptor blockage increases Aβ toxicity and cognitive impairment [136].