rats were subjected to one of two experimental treatments : ( 1 ) intraventricular infusion of the catecholamine neurotoxin 6-hydroxydopamine ( 6-ohda ) , known to permanently reduce brain dopamine and norepinephrine levels , or ( 2 ) chronic administration of the irreversible acetylcholinesterase inhibitor diisopropylfluorophosphate ( dfp ) .
C0007412
catecholamine
C0028351
norepinephrine