Abstract
Summary: The amygdaloid connections with the lower brain stem, particularly with the cardiovascular/autonomic regulatory regions- the parabrachial nuclei (PBN), nucleus of the solitary tract (NST), and dorsal motor nucleus of the vagus nerve (DMV)- were studied in the rat by means of anterograde and retrograde axonal transport of horseradish peroxidase. In the light microscope study, it was demonstrated that these regions received heavy projections from the medial subdivision of the central nucleus of the amygdala but only light projections from the lateral, and lateral capsular subdivisions. Additionally, it should be noted that the PBN had heavy projections to the lateral, and lateral capsular subdivisions of the central nucleus, while the solitary and vagal regions had light projections to the medial subdivision. In the electron microscope study, the direct amygdaloid projections to the PBN, NST and DMV were confirmed using the horseradish peroxidase technique.
