CHRNA7 and Cognitive impairment: Although varenicline is also a full agonist of α7 receptors, their impact on the restitutive effect of varenicline on impaired plasticity might be less relevant as (1) its affinity to α7 is 4000 to 5000 fold lower as compared to α4β224, (2) an α7 nAChR agonist failed to reduce nicotine withdrawal-associated cognitive deficits, as opposed to an α4β2 agonist, in another study60 and (3) in knockout mice nicotine withdrawal-related deficits in contextual fear conditioning involve β2, but not α7 subunit-containing nAChRs61.