A chimeric receptor comprising a ligand binding domain from an α7 nicotinic acetylcholine receptor fused to a transmembrane domain from a ligand-gated ion channel protein, wherein the ligand binding domain comprises an amino acid sequence from the ligand binding domain of a wild-type α7 nicotinic acetylcholine receptor with at least one mutation at positions 77, 79, 139, or 141, wherein said mutation confers selective binding to a compound having the structure of formula I: or a pharmaceutically acceptable salt thereof, wherein: A is one of: wherein, each of R 1, R 4, and R 5 is independently selected from the group of hydrogen, halo, C 1 -C 6 alkyl, C 1 -C 6 alkoxy, C 1 -C 6 thioalkyl, C 1 -C 6 haloalkyl, C 1 -C 6 thiohaloalkyl, C 1 -C 6 haloalkoxy, amino, alkylamino, dialkylamino, alkylsulfonyl, aryl and heteroaryl, wherein said aryl and heteroaryl are optionally substituted with halo, C 1 -C 6 alkyl, C 1 -C 6 alkoxyC 1 -C 6 thioalkyl, C 1 -C 6 haloalkyl, C 1 -C 6 thiohaloalkyl, C 1 -C 6 haloalkoxy, amino, alkylamino, dialkylamino or alkylsulfonyl; each of R 2 and R 3 is independently selected from the group of hydrogen, halo, C 1 -C 6 alkyl, C 1 -C 6 alkoxy, C 1 -C 6 thioalkyl, C 1 -C 6 haloalkyl, C 1 -C 6 thiohaloalkyl, C 1 -C 6 haloalkoxy, amino, alkylamino, dialkylamino, alkylsulfonyl, aryl and heteroaryl, wherein said aryl and heteroaryl are optionally substituted with halo, C 1 -C 6 alkyl, C 1 -C 6 alkoxy, C 1 -C 6 thioalkyl, C 1 -C 6 haloalkyl, C 1 -C 6 thiohaloalkyl, C 1 -C 6 haloalkoxy, amino, alkylamino, dialkylamino or alkylsulfonyl; or R 2 and R 3, together with the carbon atoms to which they are attached, form a 5 or 6-membered carbocyclic or heterocyclic ring optionally substituted with halo, C 1 -C 6 alkyl, C 1 -C 6 alkoxy, C 1 -C 6 thioalkyl, C 1 -C 6 haloalkyl, C 1 -C 6 thiohaloalkyl, C 1 -C 6 haloalkoxy, amino, alkylamino, dialkylamino, alkylsulfonyl; with the provisos that: (a) at least one of R 1, R 2, R 3, R 4 and R 5 is not hydrogen; and (b) if neither of R 1 and R 5 is C 1 -C 6 alkoxy, then R 3 is present and is not hydrogen. A is one of: wherein, each of R 1, R 4, and R 5 is independently selected from the group of hydrogen, halo, C 1 -C 6 alkyl, C 1 -C 6 alkoxy, C 1 -C 6 thioalkyl, C 1 -C 6 haloalkyl, C 1 -C 6 thiohaloalkyl, C 1 -C 6 haloalkoxy, amino, alkylamino, dialkylamino, alkylsulfonyl, aryl and heteroaryl, wherein said aryl and heteroaryl are optionally substituted with halo, C 1 -C 6 alkyl, C 1 -C 6 alkoxyC 1 -C 6 thioalkyl, C 1 -C 6 haloalkyl, C 1 -C 6 thiohaloalkyl, C 1 -C 6 haloalkoxy, amino, alkylamino, dialkylamino or alkylsulfonyl; each of R 2 and R 3 is independently selected from the group of hydrogen, halo, C 1 -C 6 alkyl, C 1 -C 6 alkoxy, C 1 -C 6 thioalkyl, C 1 -C 6 haloalkyl, C 1 -C 6 thiohaloalkyl, C 1 -C 6 haloalkoxy, amino, alkylamino, dialkylamino, alkylsulfonyl, aryl and heteroaryl, wherein said aryl and heteroaryl are optionally substituted with halo, C 1 -C 6 alkyl, C 1 -C 6 alkoxy, C 1 -C 6 thioalkyl, C 1 -C 6 haloalkyl, C 1 -C 6 thiohaloalkyl, C 1 -C 6 haloalkoxy, amino, alkylamino, dialkylamino or alkylsulfonyl; or R 2 and R 3, together with the carbon atoms to which they are attached, form a 5 or 6-membered carbocyclic or heterocyclic ring optionally substituted with halo, C 1 -C 6 alkyl, C 1 -C 6 alkoxy, C 1 -C 6 thioalkyl, C 1 -C 6 haloalkyl, C 1 -C 6 thiohaloalkyl, C 1 -C 6 haloalkoxy, amino, alkylamino, dialkylamino, alkylsulfonyl; with the provisos that: (a) at least one of R 1, R 2, R 3, R 4 and R 5 is not hydrogen; and (b) if neither of R 1 and R 5 is C 1 -C 6 alkoxy, then R 3 is present and is not hydrogen.