NONINTERACTIVE EFFECTS OF DIAZEPAM AND AMYGDALOID-LESIONS IN 2 ANIMAL-MODELS OF ANXIETY

The role of the amygdala in mediating the anxiolytic effects of diazep am was examined in two models of rat anxiety. As in our previous exper iments, amygdaloid lesions by themselves did not increase rats' explor ation of the open arms of the elevated plus-maze or decrease rats' bur ying of an electrified probe in the shock-probe burying test. However, amygdaloid lesions did increase rats' shock-probe contacts. Diazepam (2 mg/kg) increased open-arm activity and decreased burying behavior t o an equal extent in sham-lesioned and amygdala-lesioned rats and had no significant effect on the facilitation of probe contacts induced by amygdaloid lesions. These results suggest that many of the anxiolytic effects of benzodiazepines are not mediated by the amygdala.