On the Origin and Course of Sympathetic Nerve Fibers in the Fungiform Papillae of the Frog's Tongue

The precise origin and course of sympathetic nerve fibers in the fungiform papillae of the frog's tongue were investigated by the fluorescence method. Fluorescent nerve fibers were seen accompanying the blood vessels in the fungiform papillae. These fluorescent nerve fibers disappeared after cutting the glossopharyngeal nerve, but were not altered by cutting the hypoglossal nerve. Following ligation of the glossopharyngeal nerve, accumulation of yellowish green fluorescent material was found in the proximal portion of the ligated nerve. Accumulation of yellowish green fluorescent material was not observed after sympathectomy. These results suggest that sympathetic nerve fibers reach the fungiform papillae along the glossopharyngeal nerve.