title: Noradrenergic agonists and antagonists: effects on avoidance behaviour in rats.
abstract: The effects of various agonists and antagonists of both alpha and beta adrenoceptors on the acquisition of avoidance behaviour were investigated in the rat. Clonidine, a selective agonist of alpha 2 adrenoceptors depressed avoidance acquisition whilst yohimbine, an antagonist of these receptors produced an opposite effect. Prazosin which showed postsynaptic alpha 1 adrenoceptor blocking activity reduced avoidance behaviour. A similar effect was produced by propranolol, a non-selective antagonist of beta adrenoceptors. On the other hand, salbutamol preferentially stimulating beta 2 adrenoceptors facilitated avoidance behaviour. In general, the results show a fairly good correlation between avoidance acquisition and efficacy of noradrenergic neurotransmission.
mesh_terms: D000322:Adrenergic Agonists / Q000494:pharmacology*; D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects* / Q000502:physiology; D001921:Brain / Q000502:physiology*; D008297:Male; D009638:Norepinephrine / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D011941:Receptors, Adrenergic / Q000187:drug effects / Q000502:physiology*; D013565:Sympatholytics / Q000494:pharmacology*
chemical_list: D000322:Adrenergic Agonists; D011941:Receptors, Adrenergic; D013565:Sympatholytics; D009638:Norepinephrine