Role of the bed nucleus of the stria terminalis (BST) in the expression of conditioned fear.

Male Sprague-Dawley rats were trained and tested in the fear-potentiated startle (FPS) paradigm to examine the involvement of the bed nucleus of the stria terminalis (BST) in the expression of conditioned fear. Studies were designed to (a) detect physiological changes in the BST that might correlate with different levels of FPS expression and (b) determine if chemical inactivation of the BST with muscimol (1 ng) had any effect on FPS expression. The data suggest that the BST plays a role in the expression of conditioned fear and that GABA-mediated inhibition at this level may influence the level of this expression.