title: The sensory innervation of the human pharynx: searching for mechanoreceptors.
abstract: The coordinate neural regulation of the upper airways muscles is basic to control airway size and resistance. The superior constrictor pharyngeal muscle (SCPM) forms the main part of the lateral and posterior walls of the pharynx and typically is devoid of muscle spindles, the main type of proprioceptor. Because proprioception arising from SCPM is potentially important in the physiology of the upper airways, we have investigated if there are mechanical sensory nerve endings substitute for the muscle spindles. Samples of human pharynx were analyzed using immunohistochemistry associated to general axonic and Schwann cells markers (NSE, PGP 9.5, RT-97, and S100P), intrafusal muscle fiber markers, and putative mechanical sense proteins (TRPV4 and ASIC2). Different kinds of sensory corpuscles were observed in the pharynx walls (Pacini-like corpuscles, Ruffini-like corpuscles, spiral-wharves nerve structures, and others) which are supplied by sensory nerves and express putative mechanoproteins. No evidence of muscle spindles was observed. The present results demonstrate the occurrence of numerous and different morphotypes of sensory corpuscles/mechanoreceptors in human pharynx that presumably detect mechanical changes in the upper airways and replace muscle spindles for proprioception. Present findings are of potential interest for the knowledge of pathologies of the upper airways with supposed sensory pathogenesis.
authors.affiliation: Departamento de Cirugía y Especialidades Médicos-Quirúrgicas, Universidad de Oviedo, Oviedo, Spain; Instituto Asturiano de Odontología, Oviedo, Spain.
authors.forename: F
authors.initials: F
authors.lastname: de Carlos
authors.forename: J
authors.initials: J
authors.lastname: Cobo
authors.forename: E
authors.initials: E
authors.lastname: Macías
authors.forename: J
authors.initials: J
authors.lastname: Feito
authors.forename: T
authors.initials: T
authors.lastname: Cobo
authors.forename: M G
authors.initials: MG
authors.lastname: Calavia
authors.forename: O
authors.initials: O
authors.lastname: García-Suárez
authors.forename: J A
authors.initials: JA
authors.lastname: Vega
mesh_terms: D062565:Acid Sensing Ion Channels / Q000378:metabolism; D000328:Adult; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008465:Mechanoreceptors / Q000166:cytology* / Q000378:metabolism; D008875:Middle Aged; D010614:Pharynx / Q000294:innervation*; D011984:Sensory Receptor Cells / Q000166:cytology* / Q000378:metabolism; D050916:TRPV Cation Channels / Q000378:metabolism
chemical_list: C568424:ASIC2 protein, human; D062565:Acid Sensing Ion Channels; D050916:TRPV Cation Channels; C416986:TRPV4 protein, human
keywords: human; immunohistochemistry; mechanoproteins; mechanoreceptors; pharynx; superior constrictor pharyngeal muscle