To model a slow and sustained excitotoxic process as it may occur in PD, we exposed midbrain cultures to PDC, a structural analog of glutamate that does not act as an agonist of glutamate receptors on its own but does generate a toxic build‐up of the neurotransmitter in the extracellular milieu (Maki et al. The gene discussed is PDC; the disease is Parkinson disease.