A) Representative recordings showing the effects of systemic administration of the D1/5 receptor agonist SKF (500 μg/kg, i.v.) delivered following intrastriatal infusion (120 min) of either aCSF, SCH (10 μM), or 7-NI (300 μM). Dotted line indicates time of SKF-81297 injection. B) Representative recordings showing the effects of systemic administration of the D1/5 receptor agonist SKF (500 μg/kg, i.v.) delivered following intrastriatal infusion of either KYN (100 nM), CPP (100 μM), or GLY (1 mM). Dotted line indicates time of SKF injection. C) The mean ± S.E.M. increase in NO efflux evoked by DA D1/5 receptor activation was significantly reduced following intrastriatal infusion of SCH, 7-NI, KYN, CPP (*p<0.05 as compared to SKF+aCSF group using ANOVA with Dunnett's post-hoc test, n=5–6 rats/group), but not GLY (p>0.05, n=4 rats).