Brain Catecholamines: Relation to the Defense Reaction Evoked by Amygdaloid Stimulation in Cat.

Electrical stimulation of the amygdala of cats, evoking a defense reaction, was associated with a reduction in the noradrenalin content of the brain and adrenal glands but not in the dopamine content of the brain. When stimulation resulted in quieting or sleep, catecholamine concentrations were unaflected. Changes in brain noradrenalin, therefore, appear related to production of the defense response and not to nonspecific amygdalofugal pathway excitation.