CHRNA4 and Cognitive impairment: Functional analysis, using S286L-TG, which bears an S286L-mutation in the rat Chrna4 gene encoding the α4 subunit of the nicotinic acetylcholine (ACh) receptor (nAChR) corresponding to the S284L-mutation in the human CHRNA4 gene of ADSHE, demonstrated several important functional abnormalities associated with ADSHE and its comorbidity of cognitive deficit [6,7,8,12].