Identifying the cellular and molecular defects that underlie brain diseases has been limited by the lack of appropriate models. Matigian et al. describe a new model based on cells of the human olfactory mucosa, the organ of smell, that can be used to identify disease-specific changes in cellular processes and in gene and protein expression. They report both known and novel alterations associated with schizophrenia and Parkinson’s disease, and it is likely that the model can also be applied to investigate defects underlying other brain diseases.
