title: Somatotopy of the neurons innervating the cricothyroid, posterior cricoarytenoid, and thyroarytenoid muscles of the rat's larynx.
abstract: Neurons innervating the intrinsic muscles of the larynx are located within the nucleus ambiguus but the precise distribution of the neurons for each muscle is still a matter for debate. The purpose of this study was to finely determine the position and the number of the neurons innervating the intrinsic laryngeal muscles cricothyroid, posterior cricoarytenoid, and thyroarytenoid in the rat. The study was carried out in a total of 28 Sprague Dawley rats. The B subunit of the cholera toxin was employed as a retrograde tracer to determine the locations, within the nucleus ambiguus, of the neurons of these intrinsic laryngeal muscles following intramuscular injection. The labelled neurons were found ipsilaterally in the nucleus ambiguus grouped in discrete populations with reproducible rostrocaudal and dorsoventral locations among the sample of animals. Neurons innervating the cricothyroid muscle were located the most rostral of the three populations, neurons innervating the posterior cricoarytenoid were found more caudal, though there was a region of rostrocaudal overlap between these two populations. The most caudal were the neurons innervating the thyroarytenoid muscle, presenting a variable degree of overlap with the posterior cricoarytenoid muscle. The mean number (±SD) of labelled neurons was found to be 41 ± 9 for the cricothyroid, 39 ± 10 for the posterior cricoarytenoid and 33 ± 12 for the thyroarytenoid.
authors: Department of Human Anatomy and Embryology I, Faculty of Medicine, Complutense University of Madrid, Spain.
authors: Ignacio
authors: I
authors: Hernández-Morato
authors: Arán
authors: A
authors: Pascual-Font
authors: Carlos
authors: C
authors: Ramírez
authors: Jorge
authors: J
authors: Matarranz-Echeverría
authors: Stephen
authors: S
authors: McHanwell
authors: Teresa
authors: T
authors: Vázquez
authors: Jose R
authors: JR
authors: Sañudo
authors: Francisco J
authors: FJ
authors: Valderrama-Canales
mesh_terms: D000818:Animals; D002452:Cell Count; D002772:Cholera Toxin / Q000008:administration & dosage; D007273:Injections, Intramuscular; D007821:Laryngeal Muscles / Q000294:innervation*; D008297:Male; D008526:Medulla Oblongata / Q000166:cytology*; D056347:Neuroanatomical Tract-Tracing Techniques; D056325:Neuronal Tract-Tracers / Q000008:administration & dosage; D051381:Rats; D017207:Rats, Sprague-Dawley; D011984:Sensory Receptor Cells
chemical_list: D056325:Neuronal Tract-Tracers; D002772:Cholera Toxin