Dissociating the anti-fear effects of septal and amygdaloid lesions using two pharmacologically validated models of rat anxiety.

Compared the effects of septal and amygdaloid lesions in 2 models of rat anxiety. Septal lesions decreased burying behavior in the shock-probe burying test and increased open-arm exploration in the elevated plus-maze test, whereas amygdaloid lesions produced neither of these anxiolytic effects. However, amygdaloid lesions increased rats' contacts of the electrified probe, an anxiolytic effect not produced by septal lesions. Each of these distinct, anxiolytic effects of septal or amygdaloid lesions were displayed together in animals with lesions of both structures. Furthermore, the magnitude of these anxiolytic effects after combined lesions were comparable to their magnitude after individual lesions. Taken together, these results suggest that the amygdala and the septum independently control the expression of different fear-related behaviors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)