scholarly journals Impact of cervical spinal cord contusion on the breathing pattern across the sleep-wake cycle in the rat

2019 ◽  
Vol 126 (1) ◽  
pp. 111-123 ◽  
Author(s):  
Kun-Ze Lee
Keyword(s):  
Spinal Cord ◽  
Tidal Volume ◽  
Spinal Injury ◽  
Cervical Spinal Cord ◽  
Minute Ventilation ◽  
Respiratory Frequency ◽  
Breathing Patterns ◽  
Cord Injury ◽  
Spinal Contusion ◽  
Cervical Spinal Injury

The present study was designed to investigate breathing patterns across the sleep-wake state following a high cervical spinal injury in rats. The breathing patterns (e.g., respiratory frequency, tidal volume, and minute ventilation), neck electromyogram, and electroencephalography of unanesthetized adult male rats were measured at the acute (i.e., 1 day), subchronic (i.e., 2 wk), and/or chronic (i.e., 6 wk) injured stages after unilateral contusion of the second cervical spinal cord. Cervical spinal cord injury caused a long-term reduction in the tidal volume but did not influence the sleep-wake cycle duration. The minute ventilation during sleep was usually lower than that during the wake period in uninjured animals due to a decrease in respiratory frequency. However, this sleep-induced reduction in respiratory frequency was not observed in contused animals at the acute injured stage. By contrast, the tidal volume was significantly lower during sleep in contused animals but not uninjured animals from the acute to the chronic injured stage. Moreover, the frequency of sigh and postsigh apnea was elevated in acutely contused animals. These results indicated that high cervical spinal contusion is associated with exacerbated sleep-induced attenuation of the tidal volume and higher occurrence of sleep apnea, which may be detrimental to respiratory functional recovery after cervical spinal cord injury. NEW & NOTEWORTHY Cervical spinal injury is usually associated with sleep-disordered breathing. The present study investigated breathing patterns across sleep-wake state following cervical spinal injury in the rat. Unilateral cervical spinal contusion significantly impacted sleep-induced alteration of breathing patterns, showing a blunted frequency response and exacerbated attenuated tidal volume and occurrence of sleep apnea. The result enables us to investigate effects of cervical spinal injury on the pathogenesis of sleep-disordered breathing and evaluate potential therapies to improve respiration.

Effects of serotonergic agents on respiratory recovery after cervical spinal injury

2015 ◽  
Vol 119 (10) ◽  
pp. 1075-1087 ◽  
Author(s):  
Shih-Hui Hsu ◽  
Kun-Ze Lee
Keyword(s):  
Spinal Cord ◽  
Tidal Volume ◽  
Spinal Injury ◽  
Cervical Spinal Cord ◽  
Serotonergic System ◽  
Chronic Injury ◽  
Adult Rats ◽  
Respiratory Impairment ◽  
Cord Injury ◽  
Cervical Spinal Injury

Unilateral cervical spinal cord hemisection (i.e., C2Hx) usually interrupts the bulbospinal respiratory pathways and results in respiratory impairment. It has been demonstrated that activation of the serotonin system can promote locomotor recovery after spinal cord injury. The present study was designed to investigate whether serotonergic activation can improve respiratory function during the chronic injury state. Bilateral diaphragm electromyogram and tidal volume were measured in anesthetized and spontaneously breathing adult rats at 8 wk post-C2Hx or C2laminectomy. A bolus intravenous injection of a serotonin precursor [5-hydroxytryptophan (5-HTP), 10 mg/kg], a serotonin reuptake inhibitor (fluoxetine, 10 mg/kg), or a potent agonist for serotonin 2A receptors (TCB-2, 0.05 mg/kg) was used to activate the serotonergic system. Present results demonstrated that 5-HTP and TCB-2, but not fluoxetine, significantly increased the inspiratory activity of the diaphragm electromyogram ipsilateral to the lesion for at least 30 min in C2Hx animals, but not in animals that received sham surgery. However, the tidal volume was not increased after administration of 5-HTP or TCB-2, indicating that the enhancement of ipsilateral diaphragm activity is not associated with improvement of the tidal volume. These results suggest that exogenous activation of the serotonergic system can specifically enhance the ipsilateral diaphragmatic motor outputs, but this approach may not be sufficient to improve respiratory functional recovery following chronic cervical spinal 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

Cervical spinal cord injury alters the pattern of breathing in anesthetized rats

2001 ◽  
Vol 91 (6) ◽  
pp. 2451-2458 ◽  
Author(s):  
Francis J. Golder ◽  
Paul J. Reier ◽  
Paul W. Davenport ◽  
Donald C. Bolser
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Respiratory Function ◽  
Cervical Spinal Cord ◽  
Minute Ventilation ◽  
Cervical Spinal Cord Injury ◽  
Respiratory Pattern ◽  
Time Intervals ◽  
Cord Injury ◽  
Bilateral Vagotomy

The mechanisms by which chronic cervical spinal cord injury alters respiratory function and plasticity are not well understood. We speculated that spinal hemisection at C2 would alter the respiratory pattern controlled by vagal mechanisms. Expired volume (Ve) and respiratory rate (RR) were measured in anesthetized control and C2-hemisected rats at 1 and 2 mo postinjury. C2 hemisection altered the pattern of breathing at both postinjury time intervals. Injured rats utilized a higher RR and lower Ve to maintain the same minute ventilation as control rats. After bilateral vagotomy, the pattern of breathing in injured rats was not different from controls. The frequency of augmented breaths was higher in injured rats at 2 mo postinjury before vagotomy; however, the Ve of augmented breaths was not different between groups. In conclusion, C2 hemisection alters the pattern of breathing at 1 and 2 mo postinjury via vagal mechanisms.

scholarly journals Cervical Epidural Electrical Stimulation Restores Voluntary Arm Control In Paralyzed Monkeys

2020 ◽  
Author(s):  
Marco Capogrosso ◽  
Beatrice Barra ◽  
Sara Conti ◽  
Matthew Perich ◽  
Katie Zhuang ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Electrical Stimulation ◽  
Motor Control ◽  
Spinal Injury ◽  
Cervical Spinal Cord ◽  
Three Dimensional ◽  
Sensory Afferents ◽  
Reach And Grasp ◽  
Cervical Spinal Injury ◽  
Stimulation Of

Abstract Regaining arm motor control is critical for people with paralysis. Despite promising results on grasping, no technology could restore effective arm control. Here, we show that electrical stimulation of the cervical spinal cord enabled three monkeys with cervical spinal injury to execute functional arm movements. We designed an epidural interface that engaged surviving spinal circuits via the recruitment of large sensory afferents to produce movement. Simple stimulation bursts produced sustained joint movements which, triggered by movement-related intracortical signals, enabled monkeys with arm paralysis to perform an unconstrained, three-dimensional reach and grasp task. This restoration of voluntary motor control was enabled by the synergistic integration of spared descending commands and electrical stimulation within the spinal cord. The simplicity of this technology promises realistic clinical translation.

scholarly journals Multivariate Analysis of Acute Magnetic Resonance Imaging Predicts Neurological Improvements in Patients With Cervical Spinal Cord Injury After Early Surgical Decompression

Neurosurgery ◽  
2019 ◽  
Vol 66 (Supplement_1) ◽  
Author(s):  
Tomoo Inoue ◽  
Toshiki Endo ◽  
Shinsuke Suzuki ◽  
Hiroshi Uenohara ◽  
Teiji Tominaga
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Magnetic Resonance ◽  
Mr Imaging ◽  
Spinal Injury ◽  
Cervical Spinal Cord ◽  
Principal Component ◽  
Surgical Decompression ◽  
Cervical Spinal Cord Injury ◽  
Cord Injury

Abstract INTRODUCTION Patients with cervical spinal cord injury (SCI) show different clinical outcomes. There is a significant association between the acute magnetic resonance (MR) imaging of cervical SCI and neurological recovery of cervical SCI. We speculated that principal component analysis (PCA), a dimension reduction procedure, would detect clinically predictive patterns in complex MR imaging and predict neurological improvements assessed by the American Spinal Injury Association Impairment Scale (AIS) and Japanese Orthopaedic Association (JOA) score. METHODS We performed a retrospective analysis of 50 patients with cervical SCI who underwent early surgical decompression less than 48 h after the trauma. We analyzed 7 types of MR imaging assessments: axial grade assessed by the Brain and Spinal Injury Center score (BASIC), longitudinal intramedurallry lesion length, spinal cord signal intensity on T1 and T2 weighted image, maximum canal compromise, maximum spinal cord compression, Subaxial Cervical Spine Injury Classification System. PCA was applied on these multivariate data to identify factors that contribute to recovery after cervical SCI following surgery. AIS conversion was evaluated at 6 mo. RESULTS Nonlinear principal component (PC) evaluation detected 2 features of MR imaging. PCA revealed PC 1 (40.6%) explaining the intramedullary signal abnormalities that were negatively associated with postoperative AIS conversion. PC2 (18.5%) suggested extrinsic morphological variables, but did not predict outcomes. The BASIC score revealed the significant overall predictive value for AIS conversion at six months (AUC 0.86). This result suggested that the intramedullary signal abnormalities reflect delayed neurological improvements even after early surgical decompressions in patients with cervical SCI. CONCLUSION PCA could be a useful data-mining tool to show the complex relationships between acute MR imaging findings in cervical SCI. This study emphasized the importance of multivariable intramedullary MR imaging as clinical outcome predictors.

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.

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