Our findings demonstrate that a dose of vilazodone that suppresses all major subtypes of L-DOPA-induced dyskinesia in this PD model inhibited L-DOPA-induced increases in dynorphin, zif268, and 5-HT1B expression, but did not affect enkephalin expression, in the dopamine-depleted striatum, or either gene in the intact striatum. The gene discussed is PDYN; the disease is drug-induced dyskinesia.