Cardiovascular responses to electrical stimulation of the recurrent laryngeal nerve in conscious toads (Bufo marinus)

1986 ◽  
Vol 156 (3) ◽  
pp. 363-375 ◽  
Author(s):  
Bruce N. Van Vliet ◽  
Nigel H. West
1987 ◽  
Vol 96 (1) ◽  
pp. 38-42 ◽  
Author(s):  
Ira Sanders ◽  
Jonathan Aviv ◽  
Michael M. Racenstein ◽  
Warren M. Kraus ◽  
Hugh F. Biller

The recurrent laryngeal nerve (RLN) of four anesthetized adult Macaca fascicularis monkeys was stimulated by applying current with blunt electrodes placed unilaterally and bilaterally on the intact neck skin along the tracheoesophageal groove. The stimulus consisted of 2.5- to 4.0-mA cathodal pulses, each of 1-ms duration, beginning at a frequency of 10 Hz and increasing by 10-Hz increments to 100 Hz. Unilateral stimulation from 10 to 30 Hz resulted in a graded vocal cord abduction, with the maximal glottic aperture occurring at 30 Hz. Stimulation above 30 Hz produced a graded cord adduction, with nearly complete glottic closure at 100 Hz; bilateral stimulation yielded similar results, with total glottic closure at 100 Hz. Confirmation of the RLN as mediator of this frequency-dependent cord motion was achieved by surgically isolating it and attaining identical results with direct stimulation. No cardiopulmonary alterations were observed in any trial. Transcutaneous electrical stimulation of the RLN seems to be a relatively safe, reliable, and noninvasive method of controlling vocal cord position and thereby the glottic airway in monkeys.


1995 ◽  
Vol 78 (2) ◽  
pp. 441-448 ◽  
Author(s):  
T. C. Amis ◽  
A. Brancatisano ◽  
A. Tully

We measured lateral (outward) thyroid cartilage displacement (TCD) of the larynx in six supine anesthetized (intravenous chloralose) dogs. Combined left and right TCDs were measured with linear transducers attached by a thread to the thyroid alae. During tidal breathing via a tracheostomy, phasic inspiratory TCD occurred in all dogs [0.66 +/- 0.2 mm (mean +/- SE)] together with phasic inspiratory electromyographic activity in the cricothyroid (CT) and posterior cricoarytenoid (PCA) muscles. During brief tracheal occlusions, TCD increased significantly to 1.27 +/- 0.2 mm (P = 0.001), accompanied by an increase of 95–115% in the peak CT and PCA electromyograms. Bilateral supramaximal electrical stimulation of the external branches of the superior laryngeal nerve (ExSLN) produced a TCD of 9.9 +/- 0.8 mm; however, similar stimulation of the recurrent laryngeal nerve (RLN) produced a TCD of only 1.33 +/- 0.1 mm (P = 0.0001). Furthermore, bilateral section of the ExSLN in five dogs significantly reduced tidal TCD by 48.7 +/- 24.4% (P < 0.05), and bilateral section of both the ExSLN and RLN resulted in slight phasic inward TCD (-0.06 +/- 0.05 mm). Thus, it appears that the activities of both the CT and RLN-innervated muscles (probably the PCA muscle) contribute to tidal breathing TCD. These findings suggest that inspiratory dilation of the hypopharynx is mediated by contractions of CT and PCA muscles.


2014 ◽  
Vol 28 (4) ◽  
pp. 524.e1-524.e7 ◽  
Author(s):  
Alejandro Garcia Perez ◽  
Xochiquetzal Hernández López ◽  
Víctor Manuel Valadez Jiménez ◽  
Arturo Minor Martínez ◽  
Pablo Antonio Ysunza

1985 ◽  
Vol 63 (9) ◽  
pp. 1122-1132 ◽  
Author(s):  
J. A. Armour ◽  
W. C. Randall

Electrical stimulation of a canine vagosympathetic complex or a cardiopulmonary nerve can elicit a variety of negative chronotropic and inotropic cardiac responses, with or without alterations in systemic arterial pressure. In the period immediately following cessation of such a stimulation "rebound" tachycardia, increased inotropism above control values in one or more regions of the heart, and (or) elevation in systemic arterial pressure can occur. These "rebound" phenomena are abolished by propranolol or ipsilateral chronic sympathectomy. It is proposed that "vagal" poststimulation "rebound" of the canine cardiovascular system is primarily the result of activation of sympathetic neural elements present in the vagosympathetic complexes or cardiopulmonary nerves.


Biomedicines ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 369
Author(s):  
Kaori Iimura ◽  
Nobuhiro Watanabe ◽  
Philip Milliken ◽  
Yee-Hsee Hsieh ◽  
Stephen J. Lewis ◽  
...  

Electrical stimulation of myelinated afferent fibers of the superior laryngeal nerve (SLN) facilitates calcitonin secretion from the thyroid gland in anesthetized rats. In this study, we aimed to quantify the electrical SLN stimulation-induced systemic calcitonin release in conscious rats and to then clarify effects of chronic SLN stimulation on bone mineral density (BMD) in a rat ovariectomized disease model of osteoporosis. Cuff electrodes were implanted bilaterally on SLNs and after two weeks recovery were stimulated (0.5 ms, 90 microampere) repetitively at 40 Hz for 8 min. Immunoreactive calcitonin release was initially measured and quantified in systemic venous blood plasma samples from conscious healthy rats. For chronic SLN stimulation, stimuli were applied intermittently for 3–4 weeks, starting at five weeks after ovariectomy (OVX). After the end of the stimulation period, BMD of the femur and tibia was measured. SLN stimulation increased plasma immunoreactive calcitonin concentration by 13.3 ± 17.3 pg/mL (mean ± SD). BMD in proximal metaphysis of tibia (p = 0.0324) and in distal metaphysis of femur (p = 0.0510) in chronically SLN-stimulated rats was 4–5% higher than that in sham rats. Our findings demonstrate chronic electrical stimulation of the SLNs produced enhanced calcitonin release from the thyroid gland and partially improved bone loss in OVX rats.


2018 ◽  
Vol 31 (Supplement_1) ◽  
pp. 103-103
Author(s):  
Fumiaki Kawano ◽  
Shinsuke Takeno ◽  
Kousei Tashiro ◽  
Rouko Hamada ◽  
Yasuyuki Miyazaki ◽  
...  

Abstract Background Recurrent laryngeal nerve paralysis in esophagectomy is one of the most concerned complications. In recent years, intraoperative neurostimulation monitoring system (IONM) in thyroid surgery have been widespread for identification of recurrent laryngeal nerve and assessment of soundness. Therefore, IONM is often used during esophagectomy in Japan. In this study, we examined the efficacy of IONM in the patients undergoing esophagectomy. Methods Of 66 patients underwent esophagectomy since April 2015 until December 2017, IONM used in 27 patients in the surgery for the examination of recurrent nerve paralysis. We retrospectively reviewed these cases for intraoperative findings, neurostimulation monitoring findings and their outcomes. Results Of 27 patients, 25 were male and two were female, and the median age at operation was 66 years old. Although IONM was used in cervical lymph node dissection, there were no vocal cord responses in 5 patients (left side in 4 and right side in 1) with stimulation of the vagus nerve. Because all patients had no vocal cord paralysis due to stimulation of the cervical recurrent laryngeal nerve, it was diagnosed that there was the recurrent laryngeal nerve injury due to thoracic para recurrent nerve lymph node dissection. IONM was able to facilitate the identification and preservation of cervical recurrent nerve in all patients. Three out of 5 patients with no vocal cord response by IONM were confirmed recurrent laryngeal nerve paralysis in postoperative endoscope. In patients with vocal cord paralysis by IONM, it was possible to carefully performed postoperative management. On the other hand, in patients without paralysis, extubation on the operation day seemed possible without the concern for aspiration. Conclusion By using IONM in esophagectomy, we were able to evaluate the damage of the recurrent laryngeal nerve in real-time. Confirming the intraoperative recurrent nerve injuries is important for postoperative management or prediction of postoperative aspiration pneumonia. IONM in esophagectomy was useful not only in terms of surgical procedures but also in the evaluation of postoperative management. Disclosure All authors have declared no conflicts of interest.


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