Somatostatinergic projections from the amygdala to the bed nucleus of the stria terminalis and medial preoptic-hypothalamic region.

Somatostatinergic projections of the amygdala to the bed nucleus of the stria terminalis (BST) and medial preoptic-hypothalamic region were examined using a technique that combines retrograde axonal transport with peroxidase-antiperoxidase immunohistochemistry. With injections of wheat germ agglutinin-conjugated horseradish peroxidase (WGA-HRP) into either the BST or medial preoptic-hypothalamic region numerous double-labeled cells exhibiting both retrograde labeling and somatostatin-like immunoreactivity were observed in the medial amygdaloid nucleus and intra-amygdaloid portion of the BST. Additional cells were seen in the central nucleus, basomedial nucleus and anterior amygdaloid area. Although WGA-HRP labeled neurons and somatostatin-positive cells were observed in the lateral and basolateral amygdaloid nuclei, few double-labeled neurons were found.