Effect of exogenous catecholamines in the amygdala of a 'rage' cat

Minute amounts of epinephrine or norepinephrine alter the behavior of 'rage' cats (prepared by ventromedial hypothalamotomy) when these substances are focally instilled into both amygdalae via chronic brain cannulae capped with a silastic membrane. Hyperactive defense reactions are replaced by lethargy and placidity. Similar injections of epinephrine or norepinephrine into the amygdalae of normally placid cats who had not been subjected to ventromedial hypothalamotomy did not appreciably alter their behavior.