Biochemical and radioautographic evidence for dopaminergic afferents of the locus coeruleus originating in the ventral tegmental area.

The dopamine (DA) content of the locus coeruleus (LC) and the uptake of tritiated DA in the presence of desmethylimipramine into fresh vibratome sections of the LC-area were determined in control rats and in rats whose ventral tegmental area (VTA) had been destroyed by local application of 6-hydroxydopamine (6-OHDA). Destruction of the VTA reduced the DA content and the number of dopaminergic fibers visualized by radioautography in the LC area. This indicates that the DA containing afferents of the LC originate, at least partly, in the VTA.