Modification of avoidance behavior in 6-hydroxydopamine-treated rats by stimulation of central noradrenergic and dopaminergic receptors.
Rats showing reliable decrements in conditioned avoidance behavior after the intraventricular administration of 6-hydroxdopamine (6-HD) with pargyline pretreatment were given various dopaminergic and noradrenergic agonists. Intraventricular injections of DA or L-NE or intraperitoneal injections of apomorphine or L-DOPA reversed the avoidance decrements, often restoring performance to pre-6-HD-treatment levels. Furthermore, these agonists all produced behavior characteristic of activity in dopaminergic neurons. Clonidine, a noradrenergic agonist, also reversed avoidance decrements, but did not produce behavior characteristic of stimulation of dopaminergic neurons in the brain. Pretreatment with spiroperidol, a dopaminergic receptor blocker, prevented the recovery induced by all agonists, although clonidine-induced recovery was affected least. The results are discussed in terms of possible separate roles for dopaminergic and noradrenergic neurons in the brain in avoidance behavior.
D000818:Animals; D001058:Apomorphine / Q000494:pharmacology; D001362:Avoidance Learning / Q000187:drug effects / Q000502:physiology*; D001923:Brain Chemistry / Q000187:drug effects; D003000:Clonidine / Q000494:pharmacology; D004298:Dopamine / Q000032:analysis / Q000494:pharmacology / Q000502:physiology*; D006892:Hydroxydopamines / Q000494:pharmacology*; D007980:Levodopa / Q000494:pharmacology; D008297:Male; D009638:Norepinephrine / Q000032:analysis / Q000494:pharmacology / Q000502:physiology*; D010293:Pargyline / Q000494:pharmacology; D051381:Rats; D011955:Receptors, Drug / Q000187:drug effects*; D013134:Spiperone / Q000494:pharmacology
D006892:Hydroxydopamines; D011955:Receptors, Drug; D007980:Levodopa; D013134:Spiperone; D010293:Pargyline; D003000:Clonidine; D001058:Apomorphine; D004298:Dopamine; D009638:Norepinephrine