In vivo evidence for a differential contribution of striatal and nigral D1 and D2 receptors to l-DOPA induced dyskinesia and the accompanying surge of nigral amino acid levels

► l-DOPA evokes GABA and GLU levels in substantia nigra while causing dyskinesia. ► Striatal D1 but not D2 receptor blockade prevents dyskinesia and amino acid surge. ► Nigral D1 and D2 receptor blockade attenuates dyskinesia. ► Nigral D1 but not D2 receptor blockade attenuates the GABA surge.