Effects of 6-hydroxydopamine and reserpine on aggressive behavior induced by cholinomimetic and anticholinesterase injections into cerebral ventricles of conscious cats: Dissociation of biting attack from snarling and hissing

Abstract

To further examine the role of central catecholamine and 5-hydroxytryptamine neurones on affective-type aggressive behavior, the effects of carbachol, muscarine, eserine, and neostigmine on 6-hydroxydopamine-and reserpine-treated cats were examined. Carbachol, muscarine, eserine, and neostigmine, injected into the cerebral ventricles of control conscious cats, evoked emotional behavior with aggression, autonomic, and motor phenomena with clonic-tonic convulsions. The most impressive feature of the gross behavioral effects of intraventricular cholinominetics and anticholinesterase was affective-type aggression. Intraventricular 6-hydroxydopamine and reserpine, as well as parenterally administered reserpine, carbachol, muscarine, eserine, and neostigmine, elicited aggression, autonomic, and motor phenomena with clonic-tonic convulsions. Of affective-aggressive behavior, the biting attack was the most apparent, while hissing and snarling (i.e., vocalization) were depressed or absent. The most resistent to 6-hydroxydopamine and reserpine were the manifestations of affective-aggressive behavior caused by muscarine. The autonomic phenomena were of mild intensity. We conclude that intact central catecholamine and 5-hydroxytryptamine networks are required for expression of emotional behavior, especially vocalization (hissing and snarling), in affective-type aggression. However, intact central catecholamine and 5-hydroxytryptamine pathways are not needed for the performance of attack and biting phenomena.