Abstract: | Using a retrograde tracer technique with horseradish peroxidase, we have revealed some afferent projections to the locus coeruleus complex from the contralateral pontine tegmentum, raphe nuclei, substantia nigra, nucleus of the solitory tract, dorsal motor nucleus of the vagus and other regions of the ponto-bulbar reticular formation as well as from hypothalamic and preoptic areas. |