Modulation of the extrinsic tongue muscle activity in response to bronchopulmonary C-fiber activation following midcervical contusion in the rat

2020 ◽  
Vol 128 (5) ◽  
pp. 1130-1145
Author(s):  
Hsiao-Sen Chang ◽  
Kun-Ze Lee
Keyword(s):  
Spinal Cord ◽  
Muscle Activity ◽  
Cervical Spinal Cord ◽  
Upper Airway ◽  
Airway Patency ◽  
Tongue Muscle ◽  
Cord Injury ◽  
Burst Amplitude ◽  
C Fiber ◽  
Spinal Cord Contusion

Tongue muscle activity plays an important role in the regulation of upper airway patency. This study aimed to investigate the respiratory activity of the extrinsic tongue muscle in response to capsaicin-induced bronchopulmonary C-fiber activation following cervical spinal cord contusion. Midcervical spinal-contused animals exhibited a greater baseline preinspiratory burst amplitude of the extrinsic tongue muscle and were resistant to inhaled capsaicin-induced reduction of respiratory tongue muscle activity at the acute injured stage. However, inhalation of capsaicin caused a more severe attenuation of preinspiratory activity of the extrinsic tongue muscle at the chronic injured stage. These results suggest that the upper airway may be predisposed to collapse in response to bronchopulmonary C-fiber activation following chronic cervical spinal cord injury.

scholarly journals Tidal volume and diaphragm muscle activity in rats with cervical spinal cord injury

2015 ◽  
Vol 27 (3) ◽  
pp. 791-794 ◽  
Author(s):  
Hidetaka Imagita ◽  
Akira Nishikawa ◽  
Susumu Sakata ◽  
Yasue Nishii ◽  
Akira Minematsu ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Tidal Volume ◽  
Muscle Activity ◽  
Cervical Spinal Cord ◽  
Cervical Spinal Cord Injury ◽  
Diaphragm Muscle ◽  
Cord Injury

scholarly journals Surgical airway procedures in emergency surgical patients: Results of what has become a back-up procedure

2021 ◽  
Author(s):  
Gijs J. A. Willinge ◽  
Falco Hietbrink ◽  
Luke P. H. Leenen
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Functional Outcomes ◽  
Cervical Spinal Cord ◽  
Cervical Spinal Cord Injury ◽  
Surgical Patients ◽  
Trauma Patients ◽  
Airway Patency ◽  
Surgical Tracheostomy ◽  
Cord Injury

Abstract Background Cricothyroidotomy and surgical tracheostomy are methods to secure airway patency. In emergency surgery, these methods are nowadays mostly reserved for patients unsuited for percutaneous procedures. Detailed description of complications and functional outcomes following both procedures is underreported in current literature. The aim of this study was to evaluate outcomes following cricothyroidotomy and tracheostomy in this presumed complex population. Methods In this retrospective cohort study, adult emergency surgical patients treated with cricothyroidotomy and/or surgical tracheostomy were included. Postoperative complications and functional outcomes in trauma and non-trauma patients were evaluated. Results Forty-one trauma patients and 11 non-trauma emergency surgical patients (mainly after elective onco-abdominal or vascular surgery) were included. Of 52 patients, seven underwent cricothyroidotomy pre-tracheostomy. Mortality was higher in non-trauma patients (p = 0.04) following both procedures. Over half of patients (56%, n = 29) regained unsupported airway patency with a tendency toward increased tracheostomy removal in trauma patients. Among complications, only pneumonia occurred frequently (60%, n = 31), with no relation to patient type. Other complications included local infection (5.8%, n = 4) and wound dehiscence (1.9%, n = 1). Adverse functional outcomes were frequently observed and were mild and self-limiting. Cervical spinal cord injury reduced overall unsupported airway patency (p = 0.01); with high cervical spinal cord injury related to adverse functional outcomes and increased home ventilation need. Conclusions No major procedure-related complications or functional adverse events were encountered following cricothyroidotomy and surgical tracheostomy, even though only complex patients were included. Only mild, self-limiting functional problems occurred, especially in trauma patients with cervical injury who underwent early tracheostomy by longitudinal incision. This information can aid clinicians in making tailor-made decisions for individual patients.

scholarly journals Muscle activity and mood state during simulated plant factory work in individuals with cervical spinal cord injury

2016 ◽  
Vol 28 (3) ◽  
pp. 881-885 ◽  
Author(s):  
Satoshi Okahara ◽  
Masataka Kataoka ◽  
Kuniharu Okuda ◽  
Masato Shima ◽  
Keiko Miyagaki ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Muscle Activity ◽  
Mood State ◽  
Cervical Spinal Cord ◽  
Cervical Spinal Cord Injury ◽  
Cord Injury ◽  
Plant Factory

scholarly journals Altered modulation of sensorimotor rhythms with chronic paralysis

2017 ◽  
Vol 118 (4) ◽  
pp. 2412-2420 ◽  
Author(s):  
Stephen T. Foldes ◽  
Douglas J. Weber ◽  
Jennifer L. Collinger
Keyword(s):  
Spinal Cord ◽  
Motor Imagery ◽  
Muscle Activity ◽  
Cervical Spinal Cord ◽  
The Other ◽  
Emg Activity ◽  
Cortical Oscillations ◽  
Cord Injury ◽  
Intact Muscle ◽  
Sensorimotor Rhythms

After paralysis, the disconnection between the cortex and its peripheral targets leads to neuroplasticity throughout the nervous system. However, it is unclear how chronic paralysis specifically impacts cortical oscillations associated with attempted movement of impaired limbs. We hypothesized that μ- (8–13 Hz) and β- (15–30 Hz) event-related desynchronization (ERD) would be less modulated for individuals with hand paralysis due to cervical spinal cord injury (SCI). To test this, we compared the modulation of ERD from magnetoencephalography (MEG) during attempted and imagined grasping performed by participants with cervical SCI ( n = 12) and able-bodied controls ( n = 13). Seven participants with tetraplegia were able to generate some electromyography (EMG) activity during attempted grasping, whereas the other five were not. The peak and area of ERD were significantly decreased for individuals without volitional muscle activity when they attempted to grasp compared with able-bodied subjects and participants with SCI,with some residual EMG activity. However, no significant differences were found between subject groups during mentally simulated tasks (i.e., motor imagery) where no muscle activity or somatosensory consequences were expected. These findings suggest that individuals who are unable to produce muscle activity are capable of generating ERD when attempting to move, but the characteristics of this ERD are altered. However, for people who maintain volitional muscle activity after SCI, there are no significant differences in ERD characteristics compared with able-bodied controls. These results provide evidence that ERD is dependent on the level of intact muscle activity after SCI. NEW & NOTEWORTHY Source space MEG was used to investigate sensorimotor cortical oscillations in individuals with SCI. This study provides evidence that individuals with cervical SCI exhibit decreased ERD when they attempt to grasp if they are incapable of generating muscle activity. However, there were no significant differences in ERD between paralyzed and able-bodied participants during motor imagery. These results have important implications for the design and evaluation of new therapies, such as motor imagery and neurofeedback interventions.

scholarly journals 5-HT7 Receptor Inhibition Transiently Improves Respiratory Function Following Daily Acute Intermittent Hypercapnic-Hypoxia in Rats With Chronic Midcervical Spinal Cord Contusion

2020 ◽  
Vol 34 (4) ◽  
pp. 333-343
Author(s):  
Ming-Jane Wu ◽  
Stéphane Vinit ◽  
Chun-Lin Chen ◽  
Kun-Ze Lee
Keyword(s):  
Spinal Cord ◽  
Tidal Volume ◽  
Dimethyl Sulfoxide ◽  
Respiratory Function ◽  
Cervical Spinal Cord ◽  
Daily Basis ◽  
Receptor Inhibition ◽  
Cord Injury ◽  
Hypercapnic Hypoxia ◽  
Spinal Cord Contusion

Background. Intermittent hypoxia can induce respiratory neuroplasticity to enhance respiratory motor outputs following hypoxic treatment. This type of respiratory neuroplasticity is primarily mediated by the activation of Gq-protein-coupled 5-HT2 receptors and constrained by Gs-protein-coupled 5-HT7 receptors. Objective. The present study hypothesized that the blockade of 5-HT7 receptors can potentiate the effect of intermittent hypercapnic-hypoxia on respiratory function after cervical spinal cord contusion injury. Methods. The ventilatory behaviors of unanesthetized rats with midcervical spinal cord contusions were measured before, during, and after daily acute intermittent hypercapnic-hypoxia (10 episodes of 5 minutes of hypoxia [10% O2, 4% CO2, 86% N2] with 5 minutes of normoxia intervals for 5 days) at 8 weeks postinjury. On a daily basis, 5 minutes before intermittent hypercapnic-hypoxia, rats received either a 5-HT7 receptor antagonist (SB269970, 4 mg/kg, intraperitoneal) or a vehicle (dimethyl sulfoxide). Results. Treatment with intermittent hypercapnic-hypoxia induced a similar increase in tidal volume between rats that received SB269970 and those that received dimethyl sulfoxide within 60 minutes post-hypoxia on the first day. However, after 2 to 3 days of daily acute intermittent hypercapnic-hypoxia, the baseline tidal volumes of rats treated with SB269970 increased significantly. Conclusions. These results suggest that inhibiting the 5-HT7 receptor can transiently improve daily intermittent hypercapnic-hypoxia–induced tidal volume increase in midcervical spinal contused animals. Therefore, combining pharmacological treatment with rehabilitative intermittent hypercapnic-hypoxia training may be an effective strategy for synergistically enhancing respiratory neuroplasticity to improve respiratory function following chronic cervical spinal cord injury.

scholarly journals Laryngeal and swallow dysregulation following acute cervical spinal cord injury

2021 ◽  
Author(s):  
Teresa Pitts ◽  
Kimberly E Iceman ◽  
Alyssa Huff ◽  
M Nicholas Musselwhite ◽  
Michael L Frazure ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Cervical Spinal Cord ◽  
Upper Airway ◽  
Emg Activity ◽  
Post Injury ◽  
Percent Change ◽  
Cord Injury ◽  
Posterior Cricoarytenoid ◽  
Diaphragm Activity

Proper function of the larynx is vital to airway protection, including swallow. While the swallow reflex is controlled by the brainstem, patients with cervical spinal cord injuries (cSCI) are likely at increased risk of disordered swallow (dysphagia) and pneumonia, and the underlying mechanisms are unknown. We aimed to determine if acute spinal cord injury would disrupt swallow function in animal models. We hypothesized that 1) loss of descending efferent information to the diaphragm would affect swallow and breathing differently, and that 2) loss of ascending spinal afferent information would alter central swallow regulation to change motor drive to the upper airway. We recorded amplitudes of laryngeal and inspiratory muscle electromyograms (EMGs), submental and pharyngeal muscle EMGs, and cardiorespiratory measures in freely breathing pentobarbital-anesthetized cats and rats. First, we assessed the effect of a lateral hemisection at the second cervical level (C2) in cats during breathing. Posterior cricoarytenoid (laryngeal abductor) EMG activity during inspiration increased nearly two-fold, indicating that inspiratory laryngeal drive increased following cSCI. Ipsilateral to the injury, the crural diaphragm EMG was significantly reduced during breathing (62 ± 25 percent change post-injury), but no animal had a complete termination of all activity; 75% of animals had an increase in contralateral diaphragm recruitment after cSCI, but this did not reach significance. Next, we assessed the effect of C2 lateral hemisection in cats during swallow. The thyroarytenoid (laryngeal adductor) and thyropharyngeus (pharyngeal constrictor) both increased EMG activity during swallow, indicating increased upper airway drive during swallow following cSCI. There was no change in the number of swallows stimulated per trial. We also found that diaphragm activity during swallow (schluckatmung) was bilaterally suppressed after lateral C2 hemisection, which was unexpected because this injury did not suppress contralateral diaphragm activity during breathing. Swallow-breathing coordination was also affected by cSCI, with more post-injury swallows occurring during early expiration. Finally, because we wanted to determine if the chest wall is a major source of feedback for laryngeal regulation, we performed T1 total transections in rats. As in the cat C2 lateral hemisection, a similar increase in inspiratory laryngeal activity (posterior cricoarytenoid) was the first feature noted after rat T1 complete spinal cord transection. In contrast to the cat C2 lateral hemisection, diaphragmatic respiratory drive increased after T1 transection in every rat (215 ± 63 percent change), and this effect was significant. Overall, we found that spinal cord injury alters laryngeal drive during swallow and breathing, and alters swallow-related diaphragm activity. Our results show behavior-specific effects, suggesting that swallow may be more affected than breathing is by cSCI, and emphasizing the need for additional studies on laryngeal function during breathing and swallow after spinal cord injury.

Attenuation of the pulmonary chemoreflex following acute cervical spinal cord injury

2014 ◽  
Vol 116 (7) ◽  
pp. 757-766 ◽  
Author(s):  
I-Lun Tsai ◽  
Kun-Ze Lee
Keyword(s):  
Spinal Cord ◽  
Spinal Injury ◽  
Cervical Spinal Cord ◽  
Respiratory Response ◽  
Sprague Dawley ◽  
C Fibers ◽  
Cord Injury ◽  
Respiratory Airflow ◽  
C Fiber ◽  
Spontaneously Breathing

Bronchopulmonary C fibers are the primary chemosensitive afferents in the lung. The activation of bronchopulmonary C fibers evokes the pulmonary chemoreflex, which is characterized by apnea, hypotension, and bradycardia and is a critical reflex that modulates cardiorespiratory responses under physiological and pathological conditions. The present study was designed to investigate whether the pulmonary chemoreflex is altered following acute cervical spinal injury. A unilateral hemisection (Hx) or laminectomy (uninjured) in the second cervical spinal cord was performed in adult male Sprague-Dawley rats. The pulmonary chemoreflex induced by intrajugular capsaicin administration was evaluated by measuring respiratory airflow in spontaneously breathing rats and phrenic nerve activity in mechanically ventilated rats. Capsaicin treatment evoked a cessation of respiratory airflow and phrenic bursting in uninjured animals, but not in C2Hx animals. To clarify whether the attenuation of the pulmonary chemoreflex in C2Hx animals is restricted to capsaicin-induced stimuli, or generally applied to other stimuli that excite bronchopulmonary C fibers, another bronchopulmonary C-fiber stimulant (phenylbiguanide) was used to evoke the pulmonary chemoreflex in spontaneously breathing rats. We observed that phenylbiguanide-induced apnea was also blunted in C2Hx animals, suggesting that the respiratory response induced by bronchopulmonary C-fiber activation was attenuated following acute cervical spinal Hx. The blunted inhibitory respiratory response may represent a compensatory respiratory plasticity to preserve the breathing capacity and may also reduce the capability of preventing inhaled irritants in this injured condition.

scholarly journals Impact of glutamatergic and serotonergic neurotransmission on diaphragm muscle activity after cervical spinal hemisection

2017 ◽  
Vol 118 (3) ◽  
pp. 1732-1738 ◽  
Author(s):  
Carlos B. Mantilla ◽  
Heather M. Gransee ◽  
Wen-Zhi Zhan ◽  
Gary C. Sieck
Keyword(s):  
Spinal Cord ◽  
Nmda Receptor ◽  
Muscle Activity ◽  
Spontaneous Recovery ◽  
Cervical Spinal Cord ◽  
Diaphragm Muscle ◽  
Emg Activity ◽  
Emg Amplitude ◽  
Cord Injury ◽  
Phrenic Motoneuron

Incomplete cervical spinal cord hemisection at C2 (SH) disrupts descending excitatory drive to phrenic motoneurons, paralyzing the ipsilateral diaphragm muscle. Spontaneous recovery over time is associated with increased phrenic motoneuron expression of glutamatergic N-methyl-d-aspartate (NMDA) and serotonergic 5-HT2A receptors. We hypothesized that NMDA and 5-HT2A receptor-mediated neurotransmission play a role in ipsilateral diaphragm muscle activity post-SH. Adult male Sprague-Dawley rats were implanted with bilateral diaphragm EMG electrodes for chronic EMG recordings up to 28 days post-SH (SH 28D). The extent of recovery was calculated by peak root-mean-square (RMS) EMG amplitude. In all animals, absence of ipsilateral activity was verified at 3 days post-SH. Diaphragm EMG activity was also recorded during exposure to hypoxia-hypercapnia (10% O2-5% CO2). In SH animals displaying recovery of ipsilateral diaphragm EMG activity at SH 28D, cervical spinal cord segments containing the phrenic motor nucleus (C3–C5) were surgically exposed and either the NMDA receptor antagonist d-2-amino-5-phosphonovalerate (d-AP5; 100 mM, 30 μl) or 5-HT2A receptor antagonist ketanserin (40 mM, 30 μl) was instilled intrathecally. Following d-AP5, diaphragm EMG amplitude was reduced ipsilaterally, during both eupnea (42% of pre-d-AP5 value; P = 0.007) and hypoxia-hypercapnia (31% of pre-d-AP5 value; P = 0.015), with no effect on contralateral EMG activity or in uninjured controls. Treatment with ketanserin did not change ipsilateral or contralateral RMS EMG amplitude in SH animals displaying recovery at SH 28D. Our results suggest that spinal glutamatergic NMDA receptor-mediated neurotransmission plays an important role in ipsilateral diaphragm muscle activity after cervical spinal cord injury. NEW & NOTEWORTHY Spontaneous recovery following C2 spinal hemisection (SH) is associated with increased phrenic motoneuron expression of glutamatergic and serotonergic receptors. In this study, we show that pharmacological inhibition of glutamatergic N-methyl-d-aspartate (NMDA) receptors blunts ipsilateral diaphragm activity post-SH. In contrast, pharmacological inhibition of serotonergic 5-HT2A receptors does not change diaphragm EMG activity post-SH. Our results suggest that NMDA receptor-mediated glutamatergic neurotransmission plays an important role in enhancing rhythmic respiratory-related diaphragm activity after spinal cord injury.

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