Relationship of brain levels of norepinephrine and dopamine to avoidance behavior in rats after intraventricular administration of 6-hydoxydopamine.

Rats trained on a discriminated avoidance procedure showed long-term decrements in performance after intraventricular administration of 6-hydroxydopamine. Biochemical assay showed that DA levels were correlated with avoidance performance no matter when behavior was measured, but NE levels were most highly correlated with avoidance behavior at those times when suppression of responding appeared to be the major influence on responding. The data are discussed in terms of possible separate roles for NE and DA in avoidance behavior.