Abstract
The autonomic innervation of the larynx has been studied by fluorescence histochemistry and immunohistochemistry. In the laryngeal sympathetic nervous system, many problems has been solved using fluorescence histochemistry (Falck-Hillarp method) and immunohistochemistry for tyrosine hydroxylase. There are still many problems to be studied for the laryngeal parasympathetic nervous system. Advantages and disadvantages of the morphological techniques that have been used in this research field including ours were discussed in detail. Sympathetic nerve fibers were identified in the intrinsic laryngeal muscles and mucosa. In the intrinsic muscles, sympathetic nerve fiber running along the muscle fiber was observed. This finding suggests the existence of the direct sympathetic innervation of the intrinsic muscles. Using 5-hydroxydopamine technique, sympathetic innervation of the laryngeal gland was electron-microscopically clarified. Laryngeal nerves were also clarified to contain many sympathetic nerve fibers and the existence of the perivascular sympathetic innervation of the larynx was considered to be negative. CGRP immunore-activity in the laryngeal autonomic nervous system was also discussed.
