This assay serves as a foundation for the design of engineered PC12 cell lines expressing specific human nAChR isoforms to enable the study of lead compounds for the treatment of neurological diseases in which non-rα3β2-nAChR isoforms are implicated (e.g., Parkinson’s, schizophrenia, and Alzheimer’s). This evidence concerns the gene CHRNA4 and Parkinsonism.