“The ability of the dopamine D1 antagonist, SCH ….0 mg/kg) or the D2 antagonist, metoclopramide (1.0, 10.0, 20.0 mg/… with either the nonselective dopamine agonist, amphetamine (2.0 mg/kg), the D1 agonist, SKF 38393 (10.…, quinpirole (1.0 mg/kg), was evaluated in rats.”