Since the internal segment of the globus pallidus, homologous to the entopeduncular nucleus in rodents, seems to be involved in the etiopathology of l‐DOPA‐induced dyskinesia, we investigated whether the entopeduncular nucleus is modulated by the 5‐HT1A receptor partial and full agonists, buspirone, and 8‐hydroxy‐2‐(di‐n‐propylamino)‐tetralin (8‐OH‐DPAT) in control and 6‐hydroxydopamine (6‐OHDA)‐lesioned rats with or without long‐term l‐DOPA treatment. The gene discussed is HTR1A; the disease is drug-induced dyskinesia.