Projections from the Edinger-Westphal complex of monkeys as studied by means of retrograde axonal transport of horseradish peroxidase.

By means of retrograde axonal transport of horseradish peroxidase, an experimental study was made in the Japanese monkey of the projection from the anteromedian nucleus (AM) and Edinger-Westphal nucleus (EW) to the ciliary ganglon, cerebellar nuclei and spinal cord. Special attention was paid on the labeled cell forms. Neurons projecting to the cerebellar nuclei or the spinal cord were small (8-11 microns in diameter) and spindle-shaped, and they were located in almost the entire parts of both AM and EW. On the other hand, cells which gave off their axons to the ciliary ganglion were large (25-40 microns in diameter) and oval/round in shape. Their locations were confined to the medial parts of both AM and EW, except for the most caudal part of EW. In addition, a few cells in the "nucleus of Perlia" were found to project to the ciliary ganglion.