The present invention concerns a novel .alpha.7 nicotinic receptor subunit isoform, .alpha.7-2. The .alpha.7-2 isoform contributes to novel acetylcholine receptors (AChRs) with pharmacological and biophysical properties distinct from those of wild-type .alpha.7-1-nAChRs and closely resembling those of .alpha.7-nAChRs found in intrinsic cardiac neurons and Type II .alpha.7-nAChRs of superior cervical ganglion neurons. Polynucleotides encoding the .alpha.7-2 isoform, vectors and genetically modified cells containing such polynucleotides are also provided. In addition, methods are provided for producing the .alpha.7-2 isoform as are methods of using such isoforms for screening compounds for activity at the nAChR.