Origins of spinal noradrenergic pathways demonstrated by retrograde transport of antibody to dopamine-beta-hydroxylase.

Retrograde transport of antibody to dopamine-beta-hydroxylase (DBH) was used to locate the cells of origin of descending noradrenergic (and possibly adrenergic) pathways to the spinal cord. Following injections of DBH antibody into various spinal cord levels, cell bodies were immunocytochemically localized in brainstem nuclei known to contain noradrenergic neurons. These cell groups included the nucleus locus coeruleus, the nucleus subcoeruleus, the medial and lateral parabrachial nuclei, the Kölliker-Fuse nucleus, and the region dorsal and lateral to the superior olivary nucleus. Caudally, none of the noradrenergic cell groups of the medulla contained retrogradely labeled neurons. These findings indicate that the sources of spinal cord noradrenergic input are derived exclusively from the cells of the pons.