Raphe pallidus and raphe obscurus projections to the intermediolateral cell column in the rat.

The descending spinal projections from the raphe pallidus and raphe obscurus nuclei were studied by the anterograde autoradiographic technique in the rat. Both regions project to the intermediolateral cell columns. These pathways were destroyed by intraventricular injections of 5,7-dihydroxytryptamine, a neurotoxin relatively specific for serotonergic cells.