Person: Vázquez Osorio, María Teresa
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First Name
María Teresa
Last Name
Vázquez Osorio
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Medicina
Department
Anatomía y Embriología
Area
Anatomía y Embriología Humana
Identifiers
3 results
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Item Reorganization of laryngeal motoneurons after crush injury in the recurrent laryngeal nerve of the rat(Journal of Anatomy, 2013) Hernandez-Morato, Ignacio; Valderrama-Canales, Francisco J; Berdugo, Gabriel; Arias, Gonzalo; McHanwell, Stephen; Pascual-Font, Arán; Sañudo Tejero, José Ramón; Vázquez Osorio, María TeresaMotoneurons innervating laryngeal muscles are located in the nucleus ambiguus (Amb), but there is no general agreement on the somatotopic representation and even less is known on how an injury in the recurrent laryngeal nerve (RLN) affects this pattern. This study analyzes the normal somatotopy of those motoneurons and describes its changes over time after a crush injury to the RLN. In the control group (control group 1, n = 9 rats), the posterior cricoarytenoid (PCA) and thyroarytenoid (TA) muscles were injected with cholera toxin-B. In the experimental groups the left RLN of each animal was crushed with a fine tip forceps and, after several survival periods (1, 2, 4, 8, 12 weeks; minimum six rats per time), the PCA and TA muscles were injected as described above. After each surgery, the motility of the vocal folds was evaluated. Additional control experiments were performed; the second control experiment (control group 2, n = 6 rats) was performed labeling the TA and PCA immediately prior to the section of the superior laryngeal nerve (SLN), in order to eliminate the possibility of accidental labeling of the cricothyroid (CT) muscle by spread from the injection site. The third control group (control group 3, n = 5 rats) was included to determine if there is some sprouting from the SLN into the territories of the RLN after a crush of this last nerve. One week after the crush injury of the RLN, the PCA and TA muscles were injected immediately before the section of the SLN. The results show that a single population of neurons represents each muscle with the PCA in the most rostral position followed caudalwards by the TA. One week post-RLN injury, both the somatotopy and the number of labeled motoneurons changed, where the labeled neurons were distributed randomly; in addition, an area of topographical overlap of the two populations was observed and vocal fold mobility was lost. In the rest of the survival periods, the overlapping area is larger, but the movement of the vocal folds tends to recover. After 12 weeks of survival, the disorganization within the Amb is the largest, but the number of motoneurons is similar to control, and all animals recovered the movement of the left vocal fold. Our additional controls indicate that no tracer spread to the CT muscle occurred, and that many of the labeled motoneurons from the PCA after 1 week post-RLN injury correspond to motoneurons whose axons travel in the SLN. Therefore, it seems that after RLN injury there is a collateral sprouting and collateral innervation. Although the somatotopic organization of the Amb is lost after a crush injury of the RLN and does not recover in the times studied here, the movement of the vocal folds as well as the number of neurons that supply the TA and the PCA muscles recovered within 8 weeks, indicating that the central nervous system of the rat has a great capacity of plasticity.Item Somatotopy of the Neurons Innervating the Cricothyroid, Posterior Cricoarytenoid, and Thyroarytenoid Muscles of the Rat’s Larynx(The Anatomical Record, 2013) Hernández-Morato, Ignacio; Pascual-Font, Arán; Ramírez, Carlos; Matarranz-Echeverría, Jorge; McHanwell, Stephen; Sañudo, Jorge R.; Valderrama-Canales, Francisco J.; Vázquez Osorio, María TeresaNeurons 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 innervat- ing 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 ros- tral of the three populations, neurons innervating the posterior cricoary- tenoid were found more caudal, though there was a region of rostrocaudal overlap between these two populations. The most caudal were the neu- rons innervating the thyroarytenoid muscle, presenting a variable degree of overlap with the posterior cricoarytenoid muscle. The mean number (6SD) of labelled neurons was found to be 41 6 9 for the cricothyroid, 39 6 10 for the posterior cricoarytenoid and 33 6 12 for the thyroarytenoid.Item Morphogenesis of the human laryngeal ventricles(Head & Neck, 2012) Pascual-Font, Arán; Rivas, Luis; Hernández-Morato, Ignacio; Rodriguez-Niedenführ, Marc; McHanwell, Stephen; Sañudo, José R.; Viejo Tirado, Fermín; Vázquez Osorio, María TeresaBackground: Two theories explain the origin of human laryngeal ventricles: (1) ventricles derive from the fifth pharyngeal pouches; (2) development independent from the pouches. Methods: In all, there were 21 serially sectioned human embryos from stages 15 to 23, and 11 fetuses of 9 to 18 weeks. Computer-aided 3-dimentional reconstructions were made. Results: The cranial part of the laryngeal sulcus and future vestibule expands from the pharyngeal floor between the third and fourth pharyngeal pouches during stages 15 and 16 (33-37 days). The primordia of the ventricles appeared at stage 18 (44 days) as 2 lateral swellings in the caudal end of the future vestibule, limited by the third pharyngeal pouches. Active epithelial expansion and subsequent canalization during late embryonic and early fetal periods finalizes their development. Conclusions: The laryngeal ventricles do not derive from the pharyngeal pouches but the median region of the pharyngeal floor between the third and fourth pharyngeal pouches and arches at the caudal end of the future vestibule.