Relation of emotional status to spontaneous hemorrhage in rats

Bilateral septal or amygdaloid lesions were produced in rats with an electrode placed by stereotaxis. Equal numbers of the following groups of rats, amygdaloid lesion, septal lesion, amygdaloid sham, septal sham, unoperated, were randomized for examinations. All animals were evaluated preoperatively and postoperatively with emotionality ratings by four independent observers. The animals then received phenylindanedione in their diet for 10 days, at the end of which prothrombin times were determined and autopsy examinations performed. Three observers independently rated the degree of spontaneous hemorrhage, and the location of the brain lesion was confirmed histologically. A positive correlation was found between the degree of observed spontaneous hemorrhage and the emotionality rating in animals receiving anticoagulants (r = 0.85). In animals not receiving anticoagulants, less evidence of spontaneous hemorrhage was observed in animals with amygdaloid lesions than in other groups.