Afferent connections to the bed nucleus of the stria terminalis.

A systematic analysis of the distribution of cells containing horseradish peroxidase (HRP) end-product following HRP injections in the bed nucleus of the stria terminalis (BNST) revealed a topographic distribution of input from the amygdala. The appearance of HRP cells in the medial amygdaloid nucleus was associated with HRP injections in all parts of the amygdala except its most lateral portion. Injections of HRP confined to the anterolateral portion of the BNST resulted in extensive HRP labeling of cells in the basolateral amygdala, the central nucleus, and the amygdala hippocampal area. Labeling of the amygdala hippocampal area was also associated with HRP injections in the caudodorsal BNST or the supracommissural portion of the stria terminalis. Injections that labeled the commissural division of the stria terminalis produced labeling of cells in the anterior basolateral amygdala and in the nucleus of the lateral olfactory tract. The cortical and basomedial amygdaloid nuclei appear to project only weakly to the BNST. Several other regions that provide afferents to the BNST are described although their input is minor relative to that of the amygdala.