Tonic striatal glutamate release and the reuptake rate (T80) of evoked striatal glutamate in 6-OHDA-treated and cNurr1DATCreER KO mice. A, Tonic extracellular glutamate concentrations in striatum of MFB 6-OHDA-treated mice were not affected by lesion or ropinirole administration. B, Tonic extracellular glutamate concentrations were not significantly affected in cNurr1DATCreER KO mice or by TAAR1 ligands. C, Local administration of AM251 significantly enhanced tonic glutamate concentrations in cNurr1DATCreER KO mice. D, T80 was prolonged in striatum of 6-OHDA-treated mice after ejection of KCl. Local application of ropinirole inhibited this effect. E, No T80 alterations were seen in striatum of cNurr1DATCreER KO mice compared with WT mice or mice after TAAR1 ligands, ropinirole, or AM251. Coadministration with RO5166017 attenuated the AM251-induced hyperglutamatergic state. *p < 0.05, **p < 0.01 by Fisher's LSD post hoc test.