Immunohistochemical Localization of Choline Acetyltransferase in External Branch of Superior Laryngeal Nerve in Cat

인하대학교 의과대학 이비인후과학교실 병리학교실 * 해부학교실 ** 김영모·한창준·조정일·정영석· 황태숙 * ·김대중 ** = Abstract = Existence of the external branch of the superior laryngeal nerve containing afferent fibers is much of concern. In this study, it is the aim to identify the component of fibers by immunohistochemistry using choline acetyltransferase, the specific marker of the cholinergic motor neuron. Both side of external branch of superior laryngeal nerve were excised from 4 adult cats, and also obtained the great auricular nerve and the hypoglossal nerve for sensory control and motor control specimen, respectively. There were no fibers with immune reaction in the great auricular nerve while all of the fibers in the hypoglossal nerve were strongly stained with rabbit anti-choline acetyltransferase antibody. In the external branch of the superior laryngeal nerve, 12.7% of the fibers were not stained with immune reaction product. They are smaller than stained nerve fibers in cross sectioned diameter and peripherally located in the same fascicle. The identification of unstained fiber group in the external branch of the superior laryngeal nerve suggest that it is a mixed nerve and not purely motor, possibly containing the sensory nerve fiber. (Korean J Otolaryngol 40:3, 1997