Separate populations of lumbar preganglionic neurons identified with the retrograde transport of horseradish peroxidase (HRP) and 4,6-diamidino-2-phenylindole (DAPI)

Horseradish peroxidase (HRP) was applied to the central cut end of the intermesenteric trunk or the caudal lumbar sympathetic trunk in golden hamsters. Preganglionic cells labeled from the intermesenteric trunk were located in the intermediolateral cell column, bilaterally, and in the dorsal commissural nucleus. The segmental distributions of the cells in these two nuclear groups were similar. Preganglionic neurons labeled from the lumbar sympathetic trunk were located mainly in the ipsilateral intermediolateral cell column. The simultaneous application of HRP to one trunk and 4,6-diamidino-2-phenylindole (DAPI) to the other delincated two separate preganglionic cell populations. Cells labeled from the two trunks were distributed as above. HRP-filled cells and DAPI-filled cells were intermixed in the intermediolateral cell column ipsilateral to the backfilled sympathetic trunk. No double labeled cells were present. The results show that the dorsal commissural nucleus in the lumbar cord preferentially innervates prevertebral ganglia, that lumbar paravertebral ganglia are innervated by cells located mainly in the ipsilateral intermediolateral cell column, and that paravertebral and prevertebral ganglia are innervated by non-overlapping sets of lumbar preganglionic neurons.