Sympathetic projections to the epithalamus

Injections of horseradish peroxidase were made into surgically exposed superior cervical ganglia of Sprague-Dawley rats weighing 250 to 320 g. Anterogradely labeled postganglionic fibers were observed in the nervus conarii, pineal gland, pineal stalk, and the choroid plexus. Terminal fields were identified in lamina intercalaris and the medial habenular nuclei. These findings support a previous study indicating that the sole innervation of the pineal gland is via the postganglionic sympathetics.