Adrenergic control of motor activity: effects of PNMT inhibition upon open field behavior in the rat

Two inhibitors of brain PNMT were given to rats in doses which caused equivalent reductions in enzyme activity. Each drug produced similar and dose-related decreases in ambulation, rearing and defecation during open field behavioral testing. Central adrenergic (epinephrine containing) system may be necessary for normal open field behavior. This may reflect an interaction with other monoamines, particularly dopamine.