RT Journal Article SR Electronic T1 EFFECTS OF 6-HYDROXYDOPAMINE TREATMENTS ON ACTIVE AVOIDANCE RESPONDING: EVIDENCE FOR INVOLVEMENT OF BRAIN DOPAMINE JF Journal of Pharmacology and Experimental Therapeutics JO J Pharmacol Exp Ther FD American Society for Pharmacology and Experimental Therapeutics SP 358 OP 370 VO 185 IS 2 A1 BARRETT R. COOPER A1 GEORGE R. BREESE A1 LESTER D. GRANT A1 JAMES L. HOWARD YR 1973 UL http://jpet.aspetjournals.org/content/185/2/358.abstract AB Rats treated with pargyline prior to intracisternal injection of 6-hydroxydopamine (6-OHDA) failed to display acquisition of either a shuttle-box avoidance response or a one-way active avoidance response, even when tested as long as 72 days after injection. This treatment had no effect, however, on acquisition of a passive avoidance response. 6-OHDA also caused a significant decrement in performance by rats previously trained in the shuttle-box. When methods of 6-OHDA treatment were employed in which norepinephrine (NE) or dopamine (DA) was preferentially reduced in brain, animals depleted of NE displayed facilitated acquisition of the shuttle-box response, whereas depletion of DA by a single 6-OHDA treatment had little effect. Administration of α-methyltyrosine or reserpine to these preferentially depleted rats performing in the shuttle-box caused a marked decrement in performance by the DA-depleted rats but had little effect on rats depleted of NE. Two injections of 6-OHDA after desipramine treatment, which reduced DA by 85% and NE by 24%, suppressed acquisition of the avoidance response. The data, therefore, suggest that the deficit in avoidance behavior observed in 6-OHDA-treated rats is due mainly to a reduction in brain dopamine and support the view that brain catecholamines are important for the maintenance of conditioned avoidance responding. © 1973 by The Williams & Wilkins Co.