Sympathetic nerve fibers in rat orofacial and cerebral tissues as revealed by the HRP-WGA tracing technique: a light and electron microscopic study

Horseradish peroxidase-wheat germ agglutinin injected into the superior cerical ganglion is taken up by the neuronal perikarya and transported anterogradely in large quantities into peripheral fibers and axonal terminals in a variety of orofacial and cerebral tissues, including the iris, cornea, pineal gland, facial skin and the adventia of cerebral and facial blood vessels. Subsequent histochemical processing according to the tetramethylbenzidine procedure produces a unique, highly visible intraaxonal marker that makes the identification and 3-dimensional tracing of the sympathetic nerve fibers clear and unambiguous at both the light and electron microscopic levels.