title: Pituitary adenylatecyclase-activating polypeptide-immunoreactive nerve fibers in the rat epiglottis and pharynx.
abstract: The distribution of pituitary adenylatecyclase-activating polypeptide-immunoreactive (PACAP-IR) nerve fibers was studied in the rat epiglottis and pharynx. PACAP-IR nerve fibers were located beneath the mucous epithelium, and occasionally penetrated the epithelium. These nerve fibers were abundant on the laryngeal side of the epiglottis and in the dorsal and lateral border region between naso-oral and laryngeal parts of the pharynx. PACAP-IR nerve fibers were also detected in taste buds within the epiglottis and pharynx. In addition, many PACAP-IR nerve fibers were found around acinar cells and blood vessels. The double immunofluorescence method demonstrated that distribution of PACAP-IR nerve fibers was similar to that in CGRP-IR nerve fibers in the epithelium and taste bud. However, distributions of PACAP-IR and CGRP-IR nerve fibers innervating mucous glands and blood vessels were different. The retrograde tracing method also demonstrated that PACAP and CGRP were co-expressed by vagal and glossopharyngeal sensory neurons innervating the pharynx. These findings suggest that PACAP-IR nerve fibers in the epithelium and taste bud of the epiglottis and pharynx which originate from the vagal and glossopharyngeal sensory ganglia include nociceptors and chemoreceptors. The origin of PACAP-IR nerve fibers which innervate mucous glands and blood vessels may be the autonomic ganglion.
authors.affiliation: Division of Oral and Craniofacial Anatomy, Graduate School of Dentistry, Tohoku University, Sendai, Japan.
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Kano
authors.forename: Yoshinaka
authors.initials: Y
authors.lastname: Shimizu
authors.forename: Yujiro
authors.initials: Y
authors.lastname: Suzuki
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Furukawa
authors.forename: Hiroko
authors.initials: H
authors.lastname: Ishida
authors.forename: Miho
authors.initials: M
authors.lastname: Oikawa
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Kanetaka
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Ichikawa
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Suzuki
mesh_terms: D000818:Animals; D004825:Epiglottis / Q000294:innervation* / Q000378:metabolism*; D008297:Male; D009412:Nerve Fibers / Q000378:metabolism*; D010614:Pharynx / Q000294:innervation* / Q000378:metabolism*; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D051219:Pituitary Adenylate Cyclase-Activating Polypeptide