Projections of stellate ganglion sympathetic neutrons in cats.

Retrograde axonal transport of horseradish peroxidase (HRP) was used in this study to localize neurons in the cat stellate ganglion. The enzyme was applied to different nerves originating from the ganglion. Regardless of the site of HRP application labeled neurons in the stellate ganglion were located in the zone adjacent to the emergence from the ganglion of the nerves under study. However, neurons of a thoracic part of the sympathetic trunk were never labeled following exposure to HRP. The boundaries of the ganglion areas filled with labeled neurons after HRP application to different nerves did not completely overlap. The neurons labeled following HRP application to the vertebral nerve and the anastomosis of the stellate ganglion with the vagus nerve occupied the largest area. We conclude that neurons in the stellate ganglion of the cat are organized on a topical basis.