Effects of stimulation parameters on behavior elicited by stimulation of the hypothalamic defense area.

Elicited agonistic behavior by stimulating the ventromedial hypothalamus of 22 domestic cats. 12 different behavioral components were rated separately. Behavioral alerting, mydriasis, retraction of ears, piloerection, hissing, and protrusion of claws were the most characteristic components. The parameters of the stimulus were shown to be important determinants of the nature of the behavior. Results suggest that either discrete central neural circuits for the different components of agonistic behavior are diffusively organized within the ventromedial hypothalamus, or the components result from a general activation of neurons subserving discrete fixed-action patterns, the resultant behavior being determined by different factors, such as the intensity of the activation. (28 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)