Abstract
This article reviewed the recent findings on nitric oxide (NO) related to laryngeal innervation.1) NADPH-diaphorase (NADPH-d) histochemistry is considered to be as reliable as immunohistochemistry using anti-nitric oxide synthase serum for demonstration of NO in the central and peripheral innervation system. 2) NADPH-d positive nerve fibers were mainly distributed around the laryngeal gland and vessels. These nerve fibers were considered to be cholinergic and originate from NADPH-d positive neurons in the intralaryngeal ganglia. There is a species difference in the participation of NO in the laryngeal sympathetic innervation. 3) A few NADPH-d positive nerve fibers are distributed in the laryngeal epithelium, possible sensory fibers. were a few. The possibility of participation of NO in the proprioception of intrinsic muscles was pointed out. 4) NO is not involved in normal motor innervation.
