Interparental Relationship Dynamics and Cardiac Vagal Functioning in Infancy

PubMed Central

Graham, Alice M.; Ablow, Jennifer C.; Measelle, Jeffrey R.

2010-01-01

This study examined associations between interparental relationship dynamics and vagus system functioning in infancy. The functioning of the vagus system, part of the parasympathetic nervous system, indexes emotional reactivity and regulation. Interparental avoidance and dyadic adjustment constitute the focus of this study in order to bring attention to relationship dynamics not subsumed under overt conflict. Infants’ baseline vagal tone and change in vagal tone in response to a novel toy were assessed at five months in a sample of high-risk mother-infant dyads (n = 77). Maternal report of interparental avoidance demonstrated an association with infants’ baseline vagal tone, while interparental dyadic adjustment was associated with change in infants’ vagal tone from baseline to the novel toy. Infant gender moderated these associations. Maternal sensitivity did not mediate interparental relationship dynamics and infants’ vagal functioning. Results are discussed in the context of emotional security theory. PMID:20727595

Central command: control of cardiac sympathetic and vagal efferent nerve activity and the arterial baroreflex during spontaneous motor behaviour in animals.

PubMed

Matsukawa, Kanji

2012-01-01

Feedforward control by higher brain centres (termed central command) plays a role in the autonomic regulation of the cardiovascular system during exercise. Over the past 20 years, workers in our laboratory have used the precollicular-premammillary decerebrate animal model to identify the neural circuitry involved in the CNS control of cardiac autonomic outflow and arterial baroreflex function. Contrary to the traditional idea that vagal withdrawal at the onset of exercise causes the increase in heart rate, central command did not decrease cardiac vagal efferent nerve activity but did allow cardiac sympathetic efferent nerve activity to produce cardiac acceleration. In addition, central command-evoked inhibition of the aortic baroreceptor-heart rate reflex blunted the baroreflex-mediated bradycardia elicited by aortic nerve stimulation, further increasing the heart rate at the onset of exercise. Spontaneous motor activity and associated cardiovascular responses disappeared in animals decerebrated at the midcollicular level. These findings indicate that the brain region including the caudal diencephalon and extending to the rostral mesencephalon may play a role in generating central command. Bicuculline microinjected into the midbrain ventral tegmental area of decerebrate rats produced a long-lasting repetitive activation of renal sympathetic nerve activity that was synchronized with the motor nerve discharge. When lidocaine was microinjected into the ventral tegmental area, the spontaneous motor activity and associated cardiovascular responses ceased. From these findings, we conclude that cerebral cortical outputs trigger activation of neural circuits within the caudal brain, including the ventral tegmental area, which causes central command to augment cardiac sympathetic outflow at the onset of exercise in decerebrate animal models.

Surgical and conservative methods for restoring impaired motor function - facial nerve, spinal accessory nerve, hypoglossal nerve (not including vagal nerve or swallowing)

PubMed Central

Laskawi, R.; Rohrbach, S.

2005-01-01

The present review gives a survey of rehabilitative measures for disorders of the motor function of the mimetic muscles (facial nerve), and muscles innervated by the spinal accessory and hypoglossal nerves. The dysfunction can present either as paralysis or hyperkinesis (hyperkinesia). Conservative and surgical treatment options aimed at restoring normal motor function and correcting the movement disorders are described. Static reanimation techniques are not dealt with. The final section describes the use of botulinum toxin in the therapy of dysphagia. PMID:22073058

Role of central vagal 5-HT3 receptors in gastrointestinal physiology and pathophysiology

PubMed Central

Browning, Kirsteen N.

2015-01-01

Vagal neurocircuits are vitally important in the co-ordination and modulation of GI reflexes and homeostatic functions. 5-hydroxytryptamine (5-HT; serotonin) is critically important in the regulation of several of these autonomic gastrointestinal (GI) functions including motility, secretion and visceral sensitivity. While several 5-HT receptors are involved in these physiological responses, the ligand-gated 5-HT3 receptor appears intimately involved in gut-brain signaling, particularly via the afferent (sensory) vagus nerve. 5-HT is released from enterochromaffin cells in response to mechanical or chemical stimulation of the GI tract which leads to activation of 5-HT3 receptors on the terminals of vagal afferents. 5-HT3 receptors are also present on the soma of vagal afferent neurons, including GI vagal afferent neurons, where they can be activated by circulating 5-HT. The central terminals of vagal afferents also exhibit 5-HT3 receptors that function to increase glutamatergic synaptic transmission to second order neurons of the nucleus tractus solitarius within the brainstem. While activation of central brainstem 5-HT3 receptors modulates visceral functions, it is still unclear whether central vagal neurons, i.e., nucleus of the tractus solitarius (NTS) and dorsal motor nucleus of the vagus (DMV) neurons themselves also display functional 5-HT3 receptors. Thus, activation of 5-HT3 receptors may modulate the excitability and activity of gastrointestinal vagal afferents at multiple sites and may be involved in several physiological and pathophysiological conditions, including distention- and chemical-evoked vagal reflexes, nausea, and vomiting, as well as visceral hypersensitivity. PMID:26578870

[Recent progress of mitochondrial quality control in ischemic heart disease and its role in cardio-protection of vagal nerve].

PubMed

Xue, Run-Qing; Xu, Man; Yu, Xiao-Jiang; Liu, Long-Zhu; Zang, Wei-Jin

2017-10-25

Ischemic heart disease (IHD) is the life-threatening cardiovascular disease. Mitochondria have emerged as key participants and regulators of cellular energy demands and signal transduction. Mitochondrial quality is controlled by a number of coordinated mechanisms including mitochondrial fission, fusion and mitophagy, which plays an important role in maintaining healthy mitochondria and cardiac function. Recently, dysfunction of each process in mitochondrial quality control has been observed in the ischemic hearts. This review describes the mechanism of mitochondrial dynamics and mitophagy as well as its performance linked to myocardial ischemia. Moreover, in combination with our study, we will discuss the effect of vagal nerve on mitochondria in cardio-protection.

Local opiate receptors in the sinoatrial node moderate vagal bradycardia.

PubMed

Farias, M; Jackson, K; Stanfill, A; Caffrey, J L

2001-02-20

Met-enkephalin-arg-phe (MEAP) interrupts vagal bradycardia when infused into the systemic circulation. This study was designed to locate the opiate receptors functionally responsible for this inhibition. Previous observations suggested that the receptors were most likely located in either intracardiac parasympathetic ganglia or the pre-junctional nerve terminals innervating the sinoatrial node. In this study 10 dogs were instrumented with a microdialysis probe inserted into the sinoatrial node. The functional position of the probe was tested by briefly introducing norepinephrine into the probe producing an increase in heart rate of more than 30 beats/min. Vagal stimulations were conducted at 0.5, 1.2 and 4 Hz during vehicle infusion (saline ascorbate). Cardiovascular responses during vagal stimulation were recorded on-line. MEAP was infused directly into the sinoatrial node via the microdialysis probe. The evaluation of vagal bradycardia was repeated during the nodal application of MEAP, diprenorphine (opiate antagonist), and diprenorphine co-infused with MEAP. MEAP introduced into the sinoatrial node via the microdialysis probe reduced vagal bradycardia by more than half. Simultaneous local nodal blockade of these receptors with the opiate antagonist, diprenorphine, eliminated the effect of MEAP demonstrating the participation by opiate receptors. Systemic infusions of MEAP produced a reduction in vagal bradycardia nearly identical to that observed during nodal administration. When local nodal opiate receptors were blocked with diprenorphine, the systemic effect of MEAP was eliminated. These data lead us to suggest that the opiate receptors responsible for the inhibition of vagal bradycardia are located within the sinoatrial node with few, if any, participating extra-nodal or ganglionic receptors.

Blood pressure control with selective vagal nerve stimulation and minimal side effects

NASA Astrophysics Data System (ADS)

Plachta, Dennis T. T.; Gierthmuehlen, Mortimer; Cota, Oscar; Espinosa, Nayeli; Boeser, Fabian; Herrera, Taliana C.; Stieglitz, Thomas; Zentner, Joseph

2014-06-01

Objective. Hypertension is the largest threat to patient health and a burden to health care systems. Despite various options, 30% of patients do not respond sufficiently to medical treatment. Mechanoreceptors in the aortic arch relay blood pressure (BP) levels through vagal nerve (VN) fibers to the brainstem and trigger the baroreflex, lowering the BP. Selective electrical stimulation of these nerve fibers reduced BP in rats. However, there is no technique described to localize and stimulate these fibers inside the VN without inadvertent stimulation of non-baroreceptive fibers causing side effects like bradycardia and bradypnea. Approach. We present a novel method for selective VN stimulation to reduce BP without the aforementioned side effects. Baroreceptor compound activity of rat VN (n = 5) was localized using a multichannel cuff electrode, true tripolar recording and a coherent averaging algorithm triggered by BP or electrocardiogram. Main results. Tripolar stimulation over electrodes near the barofibers reduced the BP without triggering significant bradycardia and bradypnea. The BP drop was adjusted to 60% of the initial value by varying the stimulation pulse width and duration, and lasted up to five times longer than the stimulation. Significance. The presented method is robust to impedance changes, independent of the electrode's relative position, does not compromise the nerve and can run on implantable, ultra-low power signal processors.

Putative roles of neuropeptides in vagal afferent signaling

PubMed Central

de Lartigue, Guillaume

2014-01-01

The vagus nerve is a major pathway by which information is communicated between the brain and peripheral organs. Sensory neurons of the vagus are located in the nodose ganglia. These vagal afferent neurons innervate the heart, the lung and the gastrointestinal tract, and convey information about peripheral signals to the brain important in the control of cardiovascular tone, respiratory tone, and satiation, respectively. Glutamate is thought to be the primary neurotransmitter involved in conveying all of this information to the brain. It remains unclear how a single neurotransmitter can regulate such an extensive list of physiological functions from a wide range of visceral sites. Many neurotransmitters have been identified in vagal afferent neurons and have been suggested to modulate the physiological functions of glutamate. Specifically, the anorectic peptide transmitters, cocaine and amphetamine regulated transcript (CART) and the orexigenic peptide transmitters, melanin concentrating hormone (MCH) are differentially regulated in vagal afferent neurons and have opposing effects on food intake. Using these two peptides as a model, this review will discuss the potential role of peptide transmitters in providing a more precise and refined modulatory control of the broad physiological functions of glutamate, especially in relation to the control of feeding. PMID:24650553

Vagal activation by sham feeding improves gastric motility in functional dyspepsia.

PubMed

Lunding, J A; Nordström, L M; Haukelid, A-O; Gilja, O H; Berstad, A; Hausken, T

2008-06-01

Antral hypomotility and impaired gastric accommodation in patients with functional dyspepsia have been ascribed to vagal dysfunction. We investigated whether vagal stimulation by sham feeding would improve meal-induced gastric motor function in these patients. Fourteen healthy volunteers and 14 functional dyspepsia patients underwent a drink test twice, once with and once without simultaneous sham feeding. After ingesting 500 mL clear meat soup (20 kcal, 37 degrees C) in 4 min, sham feeding was performed for 10 min by chewing a sugar-containing chewing gum while spitting out saliva. Using two- and three-dimensional ultrasound, antral motility index (contraction amplitude x frequency) and intragastric volumes were estimated. Without sham feeding, functional dyspepsia patients had lower motility index than healthy volunteers (area under curve 8.0 +/- 1.2 vs 4.4 +/- 1.0 min(-1), P = 0.04). In functional dyspepsia patients, but not in healthy volunteers, motility index increased and intragastric volume tended to increase by sham feeding (P = 0.04 and P = 0.06 respectively). The change in motility index was negatively correlated to the change in pain score (r = -0.59, P = 0.007). In functional dyspepsia patients, vagal stimulation by sham feeding improves antral motility in response to a soup meal. The result supports the view that impaired vagal stimulation is implicated in the pathogenesis of gastric motility disturbances in functional dyspepsia.

Modulation of experimental arthritis by vagal sensory and central brain stimulation.

PubMed

Bassi, Gabriel Shimizu; Dias, Daniel Penteado Martins; Franchin, Marcelo; Talbot, Jhimmy; Reis, Daniel Gustavo; Menezes, Gustavo Batista; Castania, Jaci Airton; Garcia-Cairasco, Norberto; Resstel, Leonardo Barbosa Moraes; Salgado, Helio Cesar; Cunha, Fernando Queiróz; Cunha, Thiago Mattar; Ulloa, Luis; Kanashiro, Alexandre

2017-08-01

Articular inflammation is a major clinical burden in multiple inflammatory diseases, especially in rheumatoid arthritis. Biological anti-rheumatic drug therapies are expensive and increase the risk of systemic immunosuppression, infections, and malignancies. Here, we report that vagus nerve stimulation controls arthritic joint inflammation by inducing local regulation of innate immune response. Most of the previous studies of neuromodulation focused on vagal regulation of inflammation via the efferent peripheral pathway toward the viscera. Here, we report that vagal stimulation modulates arthritic joint inflammation through a novel "afferent" pathway mediated by the locus coeruleus (LC) of the central nervous system. Afferent vagal stimulation activates two sympatho-excitatory brain areas: the paraventricular hypothalamic nucleus (PVN) and the LC. The integrity of the LC, but not that of the PVN, is critical for vagal control of arthritic joint inflammation. Afferent vagal stimulation suppresses articular inflammation in the ipsilateral, but not in the contralateral knee to the hemispheric LC lesion. Central stimulation is followed by subsequent activation of joint sympathetic nerve terminals inducing articular norepinephrine release. Selective adrenergic beta-blockers prevent the effects of articular norepinephrine and thereby abrogate vagal control of arthritic joint inflammation. These results reveals a novel neuro-immune brain map with afferent vagal signals controlling side-specific articular inflammation through specific inflammatory-processing brain centers and joint sympathetic innervations. Copyright © 2017 Elsevier Inc. All rights reserved.

Vagal activity is quadratically related to prosocial traits, prosocial emotions, and observer perceptions of prosociality.

PubMed

Kogan, Aleksandr; Oveis, Christopher; Carr, Evan W; Gruber, June; Mauss, Iris B; Shallcross, Amanda; Impett, Emily A; van der Lowe, Ilmo; Hui, Bryant; Cheng, Cecilia; Keltner, Dacher

2014-12-01

In the present article, we introduce the quadratic vagal activity-prosociality hypothesis, a theoretical framework for understanding the vagus nerve's involvement in prosociality. We argue that vagus nerve activity supports prosocial behavior by regulating physiological systems that enable emotional expression, empathy for others' mental and emotional states, the regulation of one's own distress, and the experience of positive emotions. However, we contend that extremely high levels of vagal activity can be detrimental to prosociality. We present 3 studies providing support for our model, finding consistent evidence of a quadratic relationship between respiratory sinus arrhythmia--the degree to which the vagus nerve modulates the heart rate--and prosociality. Individual differences in vagal activity were quadratically related to prosocial traits (Study 1), prosocial emotions (Study 2), and outside ratings of prosociality by complete strangers (Study 3). Thus, too much or too little vagal activity appears to be detrimental to prosociality. The present article provides the 1st theoretical and empirical account of the nonlinear relationship between vagal activity and prosociality.

Central vagal sensory and motor connections: human embryonic and fetal development.

PubMed

Cheng, Gang; Zhou, Xiangtian; Qu, Jia; Ashwell, Ken W S; Paxinos, G

2004-07-30

The embryonic and fetal development of the nuclear components and pathways of vagal sensorimotor circuits in the human has been studied using Nissl staining and carbocyanine dye tracing techniques. Eight fetal brains ranging from 8 to 28 weeks of development had DiI (1,1'-dioctadecyl-3,3,3',3' tetramethylindocarbocyanine perchlorate) inserted into either the thoracic vagus nerve at the level of the sternal angle (two specimens of 8 and 9 weeks of gestation) or into vagal rootlets at the surface of the medulla (at all other ages), while a further five were used for study of cytoarchitectural development. The first central labeling resulting from peripheral application of DiI to the thoracic vagus nerve was seen at 8 weeks. By 9 weeks, labeled bipolar cells at the ventricular surface around the sulcus limitans (sl) were seen after DiI application to the thoracic vagus nerve. Subnuclear organization as revealed by both Nissl staining and carbocyanine dye tracing was found to be advanced at a relatively early fetal age, with afferent segregation in the medial Sol apparent at 13 weeks and subnuclear organization of efferent magnocellular divisions of dorsal motor nucleus of vagus nerve noticeable at the same stage. The results of the present study also confirm that vagal afferents are distributed to the dorsomedial subnuclei of the human nucleus of the solitary tract, with particular concentrations of afferent axons in the gelatinosus subnucleus. These vagal afferents appeared to have a restricted zone of termination from quite early in development (13 weeks) suggesting that there is no initial exuberance in the termination field of vagal afferents in the developing human nucleus of the solitary tract. On the other hand, the first suggestion of afferents invading 10N from the medial Sol was not seen until 20 weeks and was not well developed until 24 weeks, suggesting that direct monosynaptic connections between the sensory and effector components of the vagal

Effect of selective vagal nerve stimulation on blood pressure, heart rate and respiratory rate in rats under metoprolol medication.

PubMed

Gierthmuehlen, Mortimer; Plachta, Dennis T T

2016-02-01

Selective vagal nerve stimulation (sVNS) has been shown to reduce blood pressure without major side effects in rats. This technology might be the key to non-medical antihypertensive treatment in patients with therapy-resistant hypertension. β-blockers are the first-line therapy of hypertension and have in general a bradycardic effect. As VNS itself can also promote bradycardia, it was the aim of this study to investigate the influence of the β1-selective blocker Metoprolol on the effect of sVNS especially with respect to the heart rate. In 10 male Wistar rats, a polyimide multichannel-cuff electrode was placed around the vagal nerve bundle to selectively stimulate the aortic depressor nerve fibers. The stimulation parameters were adapted to the thresholds of individual animals and were in the following ranges: frequency 30-50 Hz, amplitude 0.3-1.8 mA and pulse width 0.3-1.3 ms. Blood pressure responses were detected with a microtip transducer in the carotid artery, and electrocardiography was recorded with s.c. chest electrodes. After IV administration of Metoprolol (2 mg kg(-1) body weight), the animals' mean arterial blood pressure (MAP) and heart rate (HR) decreased significantly. Although the selective electrical stimulation of the baroreceptive fibers reduced MAP and HR, both effects were significantly alleviated by Metoprolol. As a side effect, the rate of stimulation-induced apnea significantly increased after Metoprolol administration. sVNS can lower the MAP under Metoprolol without causing severe bradycardia.

Breathing exercises with vagal biofeedback may benefit patients with functional dyspepsia.

PubMed

Hjelland, Ina E; Svebak, Sven; Berstad, Arnold; Flatabø, Geir; Hausken, Trygve

2007-09-01

Many patients with functional dyspepsia (FD) have postprandial symptoms, impaired gastric accommodation and low vagal tone. The aim of this study was to improve vagal tone, and thereby also drinking capacity, intragastric volume and quality of life, using breathing exercises with vagal biofeedback. Forty FD patients were randomized to either a biofeedback group or a control group. The patients received similar information and care. Patients in the biofeedback group were trained in breathing exercises, 6 breaths/min, 5 min each day for 4 weeks, using specially designed software for vagal biofeedback. Effect variables included maximal drinking capacity using a drink test (Toro clear meat soup 100 ml/min), intragastric volume at maximal drinking capacity, respiratory sinus arrhythmia (RSA), skin conductance (SC) and dyspepsia-related quality of life scores. Drinking capacity and quality of life improved significantly more in the biofeedback group than in the control group (p=0.02 and p=0.01) without any significant change in baseline autonomic activity (RSA and SC) or intragastric volume. After the treatment period, RSA during breathing exercises was significantly correlated to drinking capacity (r=0.6, p=0.008). Breathing exercises with vagal biofeedback increased drinking capacity and improved quality of life in FD patients, but did not improve baseline vagal tone.

Human sympathetic and vagal baroreflex responses to sequential nitroprusside and phenylephrine

NASA Technical Reports Server (NTRS)

Rudas, L.; Crossman, A. A.; Morillo, C. A.; Halliwill, J. R.; Tahvanainen, K. U.; Kuusela, T. A.; Eckberg, D. L.

1999-01-01

We evaluated a method of baroreflex testing involving sequential intravenous bolus injections of nitroprusside followed by phenylephrine and phenylephrine followed by nitroprusside in 18 healthy men and women, and we drew inferences regarding human sympathetic and vagal baroreflex mechanisms. We recorded the electrocardiogram, photoplethysmographic finger arterial pressure, and peroneal nerve muscle sympathetic activity. We then contrasted least squares linear regression slopes derived from the depressor (nitroprusside) and pressor (phenylephrine) phases with 1) slopes derived from spontaneous fluctuations of systolic arterial pressures and R-R intervals, and 2) baroreflex gain derived from cross-spectral analyses of systolic pressures and R-R intervals. We calculated sympathetic baroreflex gain from integrated muscle sympathetic nerve activity and diastolic pressures. We found that vagal baroreflex slopes are less when arterial pressures are falling than when they are rising and that this hysteresis exists over pressure ranges both below and above baseline levels. Although pharmacological and spontaneous vagal baroreflex responses correlate closely, pharmacological baroreflex slopes tend to be lower than those derived from spontaneous fluctuations. Sympathetic baroreflex slopes are similar when arterial pressure is falling and rising; however, small pressure elevations above baseline silence sympathetic motoneurons. Vagal, but not sympathetic baroreflex gains vary inversely with subjects' ages and their baseline arterial pressures. There is no correlation between sympathetic and vagal baroreflex gains. We recommend repeated sequential nitroprusside followed by phenylephrine doses as a simple, efficientmeans to provoke and characterize human vagal and sympathetic baroreflex responses.

Role of the vagus nerve in the development and treatment of diet‐induced obesity

PubMed Central

2016-01-01

Abstract This review highlights evidence for a role of the vagus nerve in the development of obesity and how targeting the vagus nerve with neuromodulation or pharmacology can be used as a therapeutic treatment of obesity. The vagus nerve innervating the gut plays an important role in controlling metabolism. It communicates peripheral information about the volume and type of nutrients between the gut and the brain. Depending on the nutritional status, vagal afferent neurons express two different neurochemical phenotypes that can inhibit or stimulate food intake. Chronic ingestion of calorie‐rich diets reduces sensitivity of vagal afferent neurons to peripheral signals and their constitutive expression of orexigenic receptors and neuropeptides. This disruption of vagal afferent signalling is sufficient to drive hyperphagia and obesity. Furthermore neuromodulation of the vagus nerve can be used in the treatment of obesity. Although the mechanisms are poorly understood, vagal nerve stimulation prevents weight gain in response to a high‐fat diet. In small clinical studies, in patients with depression or epilepsy, vagal nerve stimulation has been demonstrated to promote weight loss. Vagal blockade, which inhibits the vagus nerve, results in significant weight loss. Vagal blockade is proposed to inhibit aberrant orexigenic signals arising in obesity as a putative mechanism of vagal blockade‐induced weight loss. Approaches and molecular targets to develop future pharmacotherapy targeted to the vagus nerve for the treatment of obesity are proposed. In conclusion there is strong evidence that the vagus nerve is involved in the development of obesity and it is proving to be an attractive target for the treatment of obesity. PMID:26959077

Allergen challenge sensitizes TRPA1 in vagal sensory neurons and afferent C-fiber subtypes in guinea pig esophagus.

PubMed

Liu, Zhenyu; Hu, Youtian; Yu, Xiaoyun; Xi, Jiefeng; Fan, Xiaoming; Tse, Chung-Ming; Myers, Allen C; Pasricha, Pankaj J; Li, Xingde; Yu, Shaoyong

2015-03-15

Transient receptor potential A1 (TRPA1) is a newly defined cationic ion channel, which selectively expresses in primary sensory afferent nerve, and is essential in mediating inflammatory nociception. Our previous study demonstrated that TRPA1 plays an important role in tissue mast cell activation-induced increase in the excitability of esophageal vagal nodose C fibers. The present study aims to determine whether prolonged antigen exposure in vivo sensitizes TRPA1 in a guinea pig model of eosinophilic esophagitis (EoE). Antigen challenge-induced responses in esophageal mucosa were first assessed by histological stains and Ussing chamber studies. TRPA1 function in vagal sensory neurons was then studied by calcium imaging and by whole cell patch-clamp recordings in 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI)-labeled esophageal vagal nodose and jugular neurons. Extracellular single-unit recordings were performed in vagal nodose and jugular C-fiber neuron subtypes using ex vivo esophageal-vagal preparations with intact nerve endings in the esophagus. Antigen challenge significantly increased infiltrations of eosinophils and mast cells in the esophagus. TRPA1 agonist allyl isothiocyanate (AITC)-induced calcium influx in nodose and jugular neurons was significantly increased, and current densities in esophageal DiI-labeled nodose and jugular neurons were also significantly increased in antigen-challenged animals. Prolonged antigen challenge decreased esophageal epithelial barrier resistance, which allowed intraesophageal-infused AITC-activating nodose and jugular C fibers at their nerve endings. Collectively, these results demonstrated that prolonged antigen challenge sensitized TRPA1 in esophageal sensory neurons and afferent C fibers. This novel finding will help us to better understand the molecular mechanism underlying esophageal sensory and motor dysfunctions in EoE. Copyright © 2015 the American Physiological Society.

Allergen challenge sensitizes TRPA1 in vagal sensory neurons and afferent C-fiber subtypes in guinea pig esophagus

PubMed Central

Liu, Zhenyu; Hu, Youtian; Yu, Xiaoyun; Xi, Jiefeng; Fan, Xiaoming; Tse, Chung-Ming; Myers, Allen C.; Pasricha, Pankaj J.; Li, Xingde

2015-01-01

Transient receptor potential A1 (TRPA1) is a newly defined cationic ion channel, which selectively expresses in primary sensory afferent nerve, and is essential in mediating inflammatory nociception. Our previous study demonstrated that TRPA1 plays an important role in tissue mast cell activation-induced increase in the excitability of esophageal vagal nodose C fibers. The present study aims to determine whether prolonged antigen exposure in vivo sensitizes TRPA1 in a guinea pig model of eosinophilic esophagitis (EoE). Antigen challenge-induced responses in esophageal mucosa were first assessed by histological stains and Ussing chamber studies. TRPA1 function in vagal sensory neurons was then studied by calcium imaging and by whole cell patch-clamp recordings in 1,1′-dioctadecyl-3,3,3′,3′-tetramethylindocarbocyanine perchlorate (DiI)-labeled esophageal vagal nodose and jugular neurons. Extracellular single-unit recordings were performed in vagal nodose and jugular C-fiber neuron subtypes using ex vivo esophageal-vagal preparations with intact nerve endings in the esophagus. Antigen challenge significantly increased infiltrations of eosinophils and mast cells in the esophagus. TRPA1 agonist allyl isothiocyanate (AITC)-induced calcium influx in nodose and jugular neurons was significantly increased, and current densities in esophageal DiI-labeled nodose and jugular neurons were also significantly increased in antigen-challenged animals. Prolonged antigen challenge decreased esophageal epithelial barrier resistance, which allowed intraesophageal-infused AITC-activating nodose and jugular C fibers at their nerve endings. Collectively, these results demonstrated that prolonged antigen challenge sensitized TRPA1 in esophageal sensory neurons and afferent C fibers. This novel finding will help us to better understand the molecular mechanism underlying esophageal sensory and motor dysfunctions in EoE. PMID:25591867

Role of intrinsic nitrergic neurones on vagally mediated striated muscle contractions in the hamster oesophagus

PubMed Central

Izumi, Noriaki; Matsuyama, Hayato; Ko, Mifa; Shimizu, Yasutake; Takewaki, Tadashi

2003-01-01

Oesophageal peristalsis is controlled by vagal motor neurones, and intrinsic neurones have been identified in the striated muscle oesophagus. However, the effect(s) of intrinsic neurones on vagally mediated contractions of oesophageal striated muscles has not been defined. The present study was designed to investigate the role of intrinsic neurones on vagally evoked contractions of oesophageal striated muscles, using hamster oesophageal strips maintained in an organ bath. Stimulation (30 μs, 20 V) of the vagus nerve trunk produced twitch contractions. Piperine inhibited vagally evoked contractions, while capsaicin and NG-nitro-L-arginine methyl ester (L-NAME) abolished the inhibitory effect of piperine. The effect of L-NAME was reversed by subsequent addition of L-arginine, but not by D-arginine. L-NAME did not have any effect on the vagally mediated contractions and presumed 3H-ACh release. NONOate, a nitric oxide donor, and dibutyryl cyclic GMP inhibited twitch contractions. Inhibition of vagally evoked contractions by piperine and NONOate was fully reversed by ODQ, an inhibitor of guanylate cyclase. Immunohistochemical staining showed immunoreactivity for nitric oxide synthase (NOS) in nerve cell bodies and fibres in the myenteric plexus and the presence of choline acetyltransferase and NOS in the motor endplates. Only a few NOS-immunoreactive portions in the myenteric plexus showed vanilloid receptor 1 (VR1) immunoreactivity. Our results suggest that there is a local neural reflex that involves capsaicin-sensitive neurones, nitrergic myenteric neurones and vagal motor neurones. PMID:12813149

Vagus Nerve as Modulator of the Brain–Gut Axis in Psychiatric and Inflammatory Disorders

PubMed Central

Breit, Sigrid; Kupferberg, Aleksandra; Rogler, Gerhard; Hasler, Gregor

2018-01-01

The vagus nerve represents the main component of the parasympathetic nervous system, which oversees a vast array of crucial bodily functions, including control of mood, immune response, digestion, and heart rate. It establishes one of the connections between the brain and the gastrointestinal tract and sends information about the state of the inner organs to the brain via afferent fibers. In this review article, we discuss various functions of the vagus nerve which make it an attractive target in treating psychiatric and gastrointestinal disorders. There is preliminary evidence that vagus nerve stimulation is a promising add-on treatment for treatment-refractory depression, posttraumatic stress disorder, and inflammatory bowel disease. Treatments that target the vagus nerve increase the vagal tone and inhibit cytokine production. Both are important mechanism of resiliency. The stimulation of vagal afferent fibers in the gut influences monoaminergic brain systems in the brain stem that play crucial roles in major psychiatric conditions, such as mood and anxiety disorders. In line, there is preliminary evidence for gut bacteria to have beneficial effect on mood and anxiety, partly by affecting the activity of the vagus nerve. Since, the vagal tone is correlated with capacity to regulate stress responses and can be influenced by breathing, its increase through meditation and yoga likely contribute to resilience and the mitigation of mood and anxiety symptoms. PMID:29593576

Plasticity of gastro-intestinal vagal afferent endings.

PubMed

Kentish, Stephen J; Page, Amanda J

2014-09-01

Vagal afferents are a vital link between the peripheral tissue and central nervous system (CNS). There is an abundance of vagal afferents present within the proximal gastrointestinal tract which are responsible for monitoring and controlling gastrointestinal function. Whilst essential for maintaining homeostasis there is a vast amount of literature emerging which describes remarkable plasticity of vagal afferents in response to endogenous as well as exogenous stimuli. This plasticity for the most part is vital in maintaining healthy processes; however, there are increased reports of vagal plasticity being disrupted in pathological states, such as obesity. Many of the disruptions, observed in obesity, have the potential to reduce vagal afferent satiety signalling which could ultimately perpetuate the obese state. Understanding how plasticity occurs within vagal afferents will open a whole new understanding of gut function as well as identify new treatment options for obesity. Copyright © 2014 Elsevier Inc. All rights reserved.

Pharyngeal dysesthesia in refractory complex partial epilepsy: new seizure or adverse effect of vagal nerve stimulation?

PubMed

Akman, Cigdem; Riviello, James J; Madsen, Joseph R; Bergin, Ann M

2003-06-01

Sensory symptoms are commonly seen in association with focal epilepsy, but viscerosensory auras, such as pharyngeal dysesthesias, are rarely the main clinical manifestation. With the introduction of vagal nerve stimulation (VNS) for medically refractory epilepsy, viscerosensory symptoms commonly occur as an adverse effect of VNS. Voice alterations (hoarseness or tremulousness), local neck or throat pain, and cough are the most common adverse effects seen during active stimulation (on-time). Numbness of the throat, neck, or chin, as well as a tingling sensation of the neck and throat is directly related to stimulation intensity. We present a case in which recurrent pharyngeal sensations caused a diagnostic dilemma and in which monitoring the VNS artifact during video/EEG and correlating this with clinical symptoms helped determine the etiology of the recurrent sensory symptoms.

Vagal Nerve Stimulation Evoked Heart Rate Changes and Protection from Cardiac Remodeling.

PubMed

Agarwal, Rahul; Mokelke, Eric; Ruble, Stephen B; Stolen, Craig M

2016-02-01

This study investigated whether vagal nerve stimulation (VNS) leads to improvements in ischemic heart failure via heart rate modulation. At 7 ± 1 days post left anterior descending artery (LAD) ligation, 63 rats with myocardial infarctions (MI) were implanted with ECG transmitters and VNS devices (MI + VNS, N = 44) or just ECG transmitters (MI, N = 17). VNS stimulation was active from 14 ± 1 days to 8 ± 1 weeks post MI. The average left ventricular (LV) end diastolic volumes at 8 ± 1 weeks were MI = 672.40 μl and MI + VNS = 519.35 μl, p = 0.03. The average heart weights, normalized to body weight (± std) at 14 ± 1 weeks were MI = 3.2 ± 0.6 g*kg(-1) and MI + VNS = 2.9 ± 0.3 g*kg(-1), p = 0.03. The degree of cardiac remodeling was correlated with the magnitude of acute VNS-evoked heart rate (HR) changes. Further research is required to determine if the acute heart rate response to VNS activation is useful as a heart failure biomarker or as a tool for VNS therapy characterization.

Improvement of Olfactory Function With High Frequency Non-invasive Auricular Electrostimulation in Healthy Humans

PubMed Central

Maharjan, Ashim; Wang, Eunice; Peng, Mei; Cakmak, Yusuf O.

2018-01-01

In past literature on animal models, invasive vagal nerve stimulation using high frequencies has shown to be effective at modulating the activity of the olfactory bulb (OB). Recent advances in invasive vagal nerve stimulation in humans, despite previous findings in animal models, used low frequency stimulation and found no effect on the olfactory functioning. The present article aimed to test potential effects of non-invasive, high and low frequency vagal nerve stimulation in humans, with supplementary exploration of the orbitofrontal cortex using near-infrared spectroscopy (NIRS). Healthy, male adult participants (n = 18) performed two olfactory tests [odor threshold test (OTT) and supra-threshold test (STT)] before and after receiving high-, low frequency vagal nerve stimulation and placebo (no stimulation). Participant's olfactory functioning was monitored using NIRS, and assessed with two behavioral olfactory tests. NIRS data of separate stimulation parameters were statistically analyzed using repeated-measures ANOVA across different stages. Data from olfactory tests were analyzed using paired parametric and non-parametric statistical tests. Only high frequency, non-invasive vagal nerve stimulation was able to positively modulate the performance of the healthy participants in the STT (p = 0.021, Wilcoxon sign-ranked test), with significant differences in NIRS (p = 0.014, post-hoc with Bonferroni correction) recordings of the right hemispheric, orbitofrontal cortex. The results from the current article implore further exploration of the neurocircuitry involved under vagal nerve stimulation and the effects of non-invasive, high frequency, vagal nerve stimulation toward olfactory dysfunction which showcase in Parkinson's and Alzheimer's Diseases. Despite the sufficient effect size (moderate effect, correlation coefficient (r): 0.39 for the STT) of the current study, future research should replicate the current findings with a larger cohort. PMID:29740266

Improvement of Olfactory Function With High Frequency Non-invasive Auricular Electrostimulation in Healthy Humans.

PubMed

Maharjan, Ashim; Wang, Eunice; Peng, Mei; Cakmak, Yusuf O

2018-01-01

In past literature on animal models, invasive vagal nerve stimulation using high frequencies has shown to be effective at modulating the activity of the olfactory bulb (OB). Recent advances in invasive vagal nerve stimulation in humans, despite previous findings in animal models, used low frequency stimulation and found no effect on the olfactory functioning. The present article aimed to test potential effects of non-invasive, high and low frequency vagal nerve stimulation in humans, with supplementary exploration of the orbitofrontal cortex using near-infrared spectroscopy (NIRS). Healthy, male adult participants ( n = 18) performed two olfactory tests [odor threshold test (OTT) and supra-threshold test (STT)] before and after receiving high-, low frequency vagal nerve stimulation and placebo (no stimulation). Participant's olfactory functioning was monitored using NIRS, and assessed with two behavioral olfactory tests. NIRS data of separate stimulation parameters were statistically analyzed using repeated-measures ANOVA across different stages. Data from olfactory tests were analyzed using paired parametric and non-parametric statistical tests. Only high frequency, non-invasive vagal nerve stimulation was able to positively modulate the performance of the healthy participants in the STT ( p = 0.021, Wilcoxon sign-ranked test), with significant differences in NIRS ( p = 0.014, post-hoc with Bonferroni correction ) recordings of the right hemispheric, orbitofrontal cortex. The results from the current article implore further exploration of the neurocircuitry involved under vagal nerve stimulation and the effects of non-invasive, high frequency, vagal nerve stimulation toward olfactory dysfunction which showcase in Parkinson's and Alzheimer's Diseases. Despite the sufficient effect size (moderate effect, correlation coefficient (r): 0.39 for the STT) of the current study, future research should replicate the current findings with a larger cohort.

Peripheral functional organisation of vagally evoked gastric motor responses in the ferret.

PubMed Central

Andrews, P L; Lawes, I N; Bower, A J

1980-01-01

The aims of the present study were to determine the relative amplitudes of intragastric motor responses evoked by different vagal branches and to establish whether the effects of acute or chronic vagotomy could be predicted from these data. Intragastric pressure responses to electrical stimulation of the vagus were measured in urethane-anaesthetised ferrets and acute or chronic vagotomies were performed. The results show that the left and right cervical vagi were equipotential and fully overlaped each other. Their contributions to the dorsal trunk were equipotential and fully overlapping and so were their contributions to the ventral trunk. The dorsal trunk was more effective than the ventral trunk and there was total functional overlap between these two trunks. Vagal evoked gastric motor responses of the ferret are apparently organised in a different way from vagally induced acid secretion or hormone release in the cat. Acute removal of a trunk led to a reduction in evoked responses that was not linear function of the effect of stimulation of that trunk. In contrast, chronic removal caused a relative increase in evoked responses that ws inversely related to the decrease caused by acute removal. The implications of total functional overlap and neuromuscular reorganisation after chronic vagotomy are discussed. PMID:7439800

A substance P antagonist inhibits vagally induced increase in vascular permeability and bronchial smooth muscle contraction in the guinea pig

PubMed Central

Lundberg, J. M.; Saria, A.; Brodin, E.; Rosell, S.; Folkers, K.

1983-01-01

Electrical stimulation of the cervical vagus nerve in anesthetized guinea pigs induced a rapid increase in respiratory insufflation pressure, suggesting increased airway resistance. After intravenous administration of a substance P (SP) antagonist, [D-Arg1,D-Pro2,D-Trp7,9,Leu11]SP, the insufflation pressure response to vagal stimulation was reduced by 78% while the cardiovascular effects were unchanged. Histamine receptor-blocking agents were used to inhibit the effects of histamine release induced by the SP-antagonist. [D-Arg1,D-Pro2,D-Trp7,9,Leu11]SP also reduced the increase in insufflation pressure caused by intravenous SP or capsaicin. The long-lasting noncholinergic contraction of the main and hilus bronchi induced by field stimulation in vitro, as well as the contractile effects of SP and capsaicin, were also blocked by the SP antagonist. The cholinergic contractions and the noncholinergic tracheal relaxation on field stimulation in vitro were, however, not blocked by the antagonist. Vagal stimulation in vivo also increased vascular permeability in the respiratory tract and esophagus, causing a subepithelial edema as indicated by Evans blue extravasation. Previous treatment with [D-Arg1,D-Pro2,D-Trp7,9,Leu11]SP inhibited the permeability increase induced by both vagus nerve stimulation and exogenous SP. SP release from vagal sensory nerves was indirectly shown by reduction in the bronchial levels of SP after nerve stimulation in vivo. The data suggest that a major portion of the vagally or capsaicin-induced increase in smooth muscle tone is caused by SP release from sensory neurons. In addition, activation of vagal SP-containing sensory nerves induces local edema. Tracheobronchial afferent SP-containing C fibers may thus exert local control of smooth muscle tone and vascular permeability in normal and pathophysiological conditions. Images PMID:6189120

Modulation of the masseteric reflex by gastric vagal afferents.

PubMed

Pettorossi, V E

1983-04-01

Several investigations have shown that the vagal nerve can affect the reflex responses of the masticatory muscles acting at level either of trigeminal motoneurons or of the mesencephalic trigeminal nucleus (MTN). The present experiments have been devoted to establish the origin of the vagal afferent fibres involved in modulating the masseteric reflex. In particular, the gastric vagal afferents were taken into consideration and selective stimulations of such fibres were performed in rabbit. Conditioning electrical stimulation of truncus vagalis ventralis (TVV) reduced the excitability of the MTN cells as shown by a decrease of the antidromic response recorded from the semilunar ganglion and elicited by MTN single-shock electrical stimulation. Sympathetic and cardiovascular influences were not involved in these responses. Mechanical stimulation of gastric receptors, by means of gastric distension, clearly diminished the amplitude of twitch tension of masseteric reflex and inhibited the discharge frequency of proprioceptive MTN units. The effect was phasic and depended upon the velocity of distension. Thus the sensory volleys originating from rapid adapting receptors reach the brain stem through vagal afferents and by means of a polysynaptic connection inhibits the masseteric reflex at level of MTN cells.

Anti-inflammatory effects and mechanisms of vagal nerve stimulation combined with electroacupuncture in a rodent model of TNBS-induced colitis.

PubMed

Jin, Haifeng; Guo, Jie; Liu, Jiemin; Lyu, Bin; Foreman, Robert D; Yin, Jieyun; Shi, Zhaohong; Chen, Jiande D Z

2017-09-01

The purpose of this study was to determine the effects and mechanisms of vagal nerve stimulation (VNS) and additive effects of electroacupuncture (EA) on colonic inflammation in a rodent model of IBD. Chronic inflammation in rats was induced by intrarectal TNBS (2,4,6-trinitrobenzenesulfonic acid). The rats were then treated with sham ES (electrical stimulation), VNS, or VNS + EA for 3 wk. Inflammatory responses were assessed by disease activity index (DAI), macroscopic scores and histological scores of colonic tissues, plasma levels of TNFα, IL-1β, and IL-6, and myeloperoxidase (MPO) activity of colonic tissues. The autonomic function was assessed by the spectral analysis of heart rate variability (HRV) derived from the electrocardiogram. It was found that 1 ) the area under curve (AUC) of DAI was substantially decreased with VNS + EA and VNS, with VNS + EA being more effective than VNS ( P < 0.001); 2 ) the macroscopic score was 6.43 ± 0.61 in the sham ES group and reduced to 1.86 ± 0.26 with VNS ( P < 0.001) and 1.29 ± 0.18 with VNS + EA ( P < 0.001); 3 ) the histological score was 4.05 ± 0.58 in the sham ES group and reduced to 1.93 ± 0.37 with VNS ( P < 0.001) and 1.36 ± 0.20 with VNS + EA ( P < 0.001); 4 ) the plasma levels of TNFα, IL-1β, IL-6, and MPO were all significantly decreased with VNS and VNS + EA compared with the sham ES group; and 5 ) autonomically, both VNS + EA and VNS substantially increased vagal activity and decreased sympathetic activity compared with sham EA ( P < 0.001, P < 0.001, respectively). In conclusion, chronic VNS improves inflammation in TNBS-treated rats by inhibiting proinflammatory cytokines via the autonomic mechanism. Addition of noninvasive EA to VNS may enhance the anti-inflammatory effect of VNS. NEW & NOTEWORTHY This is the first study to address and compare the effects of vagal nerve stimulation (VNS), electrical acupuncture (EA) and VNS + EA on TNBS (2,4,6-trinitrobenzenesulfonic acid

Vagal tone during infant contingency learning and its disruption.

PubMed

Sullivan, Margaret Wolan

2016-04-01

This study used contingency learning to examine changes in infants' vagal tone during learning and its disruption. The heart rate of 160 five-month-old infants was recorded continuously during the first of two training sessions as they experienced an audiovisual event contingent on their pulling. Maternal reports of infant temperament were also collected. Baseline vagal tone, a measure of parasympathetic regulation of the heart, was related to vagal levels during the infants' contingency learning session, but not to their learner status. Vagal tone levels did not vary significantly over session minutes. Instead, vagal tone levels were a function of both individual differences in learner status and infant soothability. Vagal levels of infants who learned in the initial session were similar regardless of their soothability; however, vagal levels of infants who learned in a subsequent session differed as a function of soothability. Additionally, vagal levels during contingency disruption were significantly higher among infants in this group who were more soothable as opposed to those who were less soothable. The results suggest that contingency learning and disruption is associated with stable vagal tone in the majority of infants, but that individual differences in attention processes and state associated with vagal tone may be most readily observed during the disruption phase. © 2015 Wiley Periodicals, Inc.

Vagal Tone During Infant Contingency Learning and Its Disruption

PubMed Central

Sullivan, Margaret Wolan

2015-01-01

This study used contingency learning to examine changes in infants’ vagal tone during learning and its disruption. The heart rate of 160 five-month-old infants was recorded continuously during the first of two training sessions as they experienced an audiovisual event contingent on their pulling. Maternal reports of infant temperament were also collected. Baseline vagal tone, a measure of parasympathetic regulation of the heart, was related to vagal levels during the infants’ contingency learning session, but not to their learner status. Vagal tone levels did not vary significantly over session minutes. Instead, vagal tone levels were a function of both individual differences in learner status and infant soothability. Vagal levels of infants who learned in the initial session were similar regardless of their soothability; however, vagal levels of infants who learned in a subsequent session differed as a function of soothability. Additionally, vagal levels during contingency disruption were significantly higher among infants in this group who were more soothable as opposed to those who were less soothable. The results suggest that contingency learning and disruption is associated with stable vagal tone in the majority of infants, but that individual differences in attention processes and state associated with vagal tone may be most readily observed during the disruption phase. PMID:26517573

Age-specific associations between cardiac vagal activity and functional somatic symptoms: a population-based study.

PubMed

Tak, Lineke M; Janssens, Karin A M; Dietrich, Andrea; Slaets, Joris P J; Rosmalen, Judith G M

2010-01-01

Functional somatic symptoms (FSS) are symptoms not explained by underlying organic pathology. It has frequently been suggested that dysfunction of the autonomic nervous system (ANS) contributes to the development of FSS. We hypothesized that decreased cardiac vagal activity is cross-sectionally and prospectively associated with the number of FSS in the general population. This study was performed in a population-based cohort of 774 adults (45.1% male, mean age +/- SD 53.5 +/- 10.7 years). Participants completed the somatization section of the Composite International Diagnostic Interview surveying the presence of 43 FSS. ANS function was assessed by spectral analysis of heart rate variability in the high-frequency band (HRV-HF), reflecting cardiac vagal activity. Follow-up measurements of HRV-HF and FSS were performed approximately 2 years later. Linear regression analyses, with adjustments for gender, age, body mass index, anxiety, depression, smoking, alcohol use, and frequency of exercise, revealed an interaction of cardiac vagal activity with age: HRV-HF was negatively associated with FSS in adults 52 years (beta = 0.13, t = 2.51, p = 0.012). Longitudinal analysis demonstrated a similar pattern. Decreased cardiac vagal activity is associated with a higher number of FSS in adults aged vagal activity and FSS in adults aged >52 years needs further exploration. The role of age should be acknowledged in future studies on ANS function in the etiology of FSS. (c) 2010 S. Karger AG, Basel.

Central-peripheral neural network interactions evoked by vagus nerve stimulation: functional consequences on control of cardiac function.

PubMed

Ardell, Jeffrey L; Rajendran, Pradeep S; Nier, Heath A; KenKnight, Bruce H; Armour, J Andrew

2015-11-15

Using vagus nerve stimulation (VNS), we sought to determine the contribution of vagal afferents to efferent control of cardiac function. In anesthetized dogs, the right and left cervical vagosympathetic trunks were stimulated in the intact state, following ipsilateral or contralateral vagus nerve transection (VNTx), and then following bilateral VNTx. Stimulations were performed at currents from 0.25 to 4.0 mA, frequencies from 2 to 30 Hz, and a 500-μs pulse width. Right or left VNS evoked significantly greater current- and frequency-dependent suppression of chronotropic, inotropic, and lusitropic function subsequent to sequential VNTx. Bradycardia threshold was defined as the current first required for a 5% decrease in heart rate. The threshold for the right vs. left vagus-induced bradycardia in the intact state (2.91 ± 0.18 and 3.47 ± 0.20 mA, respectively) decreased significantly with right VNTx (1.69 ± 0.17 mA for right and 3.04 ± 0.27 mA for left) and decreased further following bilateral VNTx (1.29 ± 0.16 mA for right and 1.74 ± 0.19 mA for left). Similar effects were observed following left VNTx. The thresholds for afferent-mediated effects on cardiac parameters were 0.62 ± 0.04 and 0.65 ± 0.06 mA with right and left VNS, respectively, and were reflected primarily as augmentation. Afferent-mediated tachycardias were maintained following β-blockade but were eliminated by VNTx. The increased effectiveness and decrease in bradycardia threshold with sequential VNTx suggest that 1) vagal afferents inhibit centrally mediated parasympathetic efferent outflow and 2) the ipsilateral and contralateral vagi exert a substantial buffering capacity. The intact threshold reflects the interaction between multiple levels of the cardiac neural hierarchy. Copyright © 2015 the American Physiological Society.

Central-peripheral neural network interactions evoked by vagus nerve stimulation: functional consequences on control of cardiac function

PubMed Central

Rajendran, Pradeep S.; Nier, Heath A.; KenKnight, Bruce H.; Armour, J. Andrew

2015-01-01

Using vagus nerve stimulation (VNS), we sought to determine the contribution of vagal afferents to efferent control of cardiac function. In anesthetized dogs, the right and left cervical vagosympathetic trunks were stimulated in the intact state, following ipsilateral or contralateral vagus nerve transection (VNTx), and then following bilateral VNTx. Stimulations were performed at currents from 0.25 to 4.0 mA, frequencies from 2 to 30 Hz, and a 500-μs pulse width. Right or left VNS evoked significantly greater current- and frequency-dependent suppression of chronotropic, inotropic, and lusitropic function subsequent to sequential VNTx. Bradycardia threshold was defined as the current first required for a 5% decrease in heart rate. The threshold for the right vs. left vagus-induced bradycardia in the intact state (2.91 ± 0.18 and 3.47 ± 0.20 mA, respectively) decreased significantly with right VNTx (1.69 ± 0.17 mA for right and 3.04 ± 0.27 mA for left) and decreased further following bilateral VNTx (1.29 ± 0.16 mA for right and 1.74 ± 0.19 mA for left). Similar effects were observed following left VNTx. The thresholds for afferent-mediated effects on cardiac parameters were 0.62 ± 0.04 and 0.65 ± 0.06 mA with right and left VNS, respectively, and were reflected primarily as augmentation. Afferent-mediated tachycardias were maintained following β-blockade but were eliminated by VNTx. The increased effectiveness and decrease in bradycardia threshold with sequential VNTx suggest that 1) vagal afferents inhibit centrally mediated parasympathetic efferent outflow and 2) the ipsilateral and contralateral vagi exert a substantial buffering capacity. The intact threshold reflects the interaction between multiple levels of the cardiac neural hierarchy. PMID:26371171

Anterograde Tracing Method using DiI to Label Vagal Innervation of the Embryonic and Early Postnatal Mouse Gastrointestinal Tract

PubMed Central

Murphy, Michelle C.; Fox, Edward A.

2007-01-01

The mouse is an extremely valuable model for studying vagal development in relation to strain differences, genetic variation, gene manipulations, or pharmacological manipulations. Therefore, a method using 1, 1′-dioctadecyl-3,3,3′,3′-tetramethylindocarbocyanine perchlorate (DiI) was developed for labeling vagal innervation of the gastrointestinal (GI) tract in embryonic and postnatal mice. DiI labeling was adapted and optimized for this purpose by varying several facets of the method. For example, insertion and crushing of DiI crystals into the nerve led to faster DiI diffusion along vagal axons and diffusion over longer distances as compared with piercing the nerve with a micropipette tip coated with dried DiI oil. Moreover, inclusion of EDTA in the fixative reduced leakage of DiI out of nerve fibers that occurred with long incubations. Also, mounting labeled tissue in PBS was superior to glycerol with n-propyl gallate, which resulted in reduced clarity of DiI labeling that may have been due to DiI leaking out of fibers. Optical sectioning of flattened wholemounts permitted examination of individual tissue layers of the GI tract wall. This procedure aided identification of nerve ending types because in most instances each type innervates a different tissue layer. Between embryonic day 12.5 and postnatal day 8, growth of axons into the GI tract, formation and patterning of fiber bundles in the myenteric plexus and early formation of putative afferent and efferent nerve terminals were observed. Thus, the DiI tracing method developed here has opened up a window for investigation during an important phase of vagal development. PMID:17418900

Cardiac vagal regulation in infancy predicts executive function and social competence in preschool: Indirect effects through language.

PubMed

Whedon, Margaret; Perry, Nicole B; Calkins, Susan D; Bell, Martha Ann

2018-05-21

Parasympathetic nervous system functioning in infancy may serve a foundational role in the development of cognitive and socioemotional skills (Calkins, 2007). In this study (N = 297), we investigated the potential indirect effects of cardiac vagal regulation in infancy on children's executive functioning and social competence in preschool via expressive and receptive language in toddlerhood. Vagal regulation was assessed at 10 months during two attention conditions (social, nonsocial) via task-related changes in respiratory sinus arrhythmia (RSA). A path analysis revealed that decreased RSA from baseline in the nonsocial condition and increased RSA in the social condition were related to larger vocabularies in toddlerhood. Additionally, children's vocabulary sizes were positively related to their executive function and social competence in preschool. Indirect effects from vagal regulation in both contexts to both 4-year outcomes were significant, suggesting that early advances in language may represent a mechanism through which biological functioning in infancy impacts social and cognitive functioning in childhood. © 2018 Wiley Periodicals, Inc.

Motor evoked potential monitoring of the vagus nerve with transcranial electrical stimulation during skull base surgeries.

PubMed

Ito, Eiji; Ichikawa, Masahiro; Itakura, Takeshi; Ando, Hitoshi; Matsumoto, Yuka; Oda, Keiko; Sato, Taku; Watanabe, Tadashi; Sakuma, Jun; Saito, Kiyoshi

2013-01-01

Dysphasia is one of the most serious complications of skull base surgeries and results from damage to the brainstem and/or cranial nerves involved in swallowing. Here, the authors propose a method to monitor the function of the vagus nerve using endotracheal tube surface electrodes and transcranial electrical stimulation during skull base surgeries. Fifteen patients with skull base or brainstem tumors were enrolled. The authors used surface electrodes of an endotracheal tube to record compound electromyographic responses from the vocalis muscle. Motor neurons were stimulated using corkscrew electrodes placed subdermally on the scalp at C3 and C4. During surgery, the operator received a warning when the amplitude of the vagal motor evoked potential (MEP) decreased to less than 50% of the control level. After surgery, swallowing function was assessed clinically using grading criteria. In 5 patients, vagal MEP amplitude permanently deteriorated to less than 50% of the control level on the right side when meningiomas were dissected from the pons or basilar artery, or when a schwannoma was dissected from the vagal rootlets. These 5 patients had postoperative dysphagia. At 4 weeks after surgery, 2 patients still had dysphagia. In 2 patients, vagal MEPs of one side transiently disappeared when the tumors were dissected from the brainstem or the vagal rootlets. After surgery, both patients had dysphagia, which recovered in 4 weeks. In 7 patients, MEP amplitude was consistent, maintaining more than 50% of the control level throughout the operative procedures. After surgery all 7 patients were neurologically intact with normal swallowing function. Vagal MEP monitoring with transcranial electrical stimulation and endotracheal tube electrode recording was a safe and effective method to provide continuous real-time information on the integrity of both the supranuclear and infranuclear vagal pathway. This method is useful to prevent intraoperative injury of the brainstem

Plasticity of vagal brainstem circuits in the control of gastric function

PubMed Central

Browning, Kirsteen N.; Travagli, R. Alberto

2010-01-01

Background Sensory information from the viscera, including the gastrointestinal (GI) tract, is transmitted through the afferent vagus via a glutamatergic synapse to neurons of the nucleus tractus solitarius (NTS), which integrate this sensory information to regulate autonomic functions and homeostasis. The integrated response is conveyed to, amongst other nuclei, the preganglionic neurons of the dorsal motor nucleus of the vagus (DMV) using mainly GABA, glutamate and catecholamines as neurotransmitters. Despite being modulated by almost all the neurotransmitters tested so far, the glutamatergic synapse between NTS and DMV does not appear to be tonically active in the control of gastric motility and tone. Conversely, tonic inhibitory GABAergic neurotransmission from the NTS to the DMV appears critical in setting gastric tone and motility, yet, under basal conditions, this synapse appears resistant to modulation. Purpose Here, we review the available evidence suggesting that vagal efferent output to the GI tract is regulated, perhaps even controlled, in an “on-demand” and efficient manner in response to ever-changing homeostatic conditions. The focus of this review is on the plasticity induced by variations in the levels of second messengers in the brainstem neurons that form vago-vagal reflex circuits. Emphasis is placed upon the modulation of GABAergic transmission to DMV neurons and the modulation of afferent input from the GI tract by neurohormones/neurotransmitters and macronutrients. Derangement of this “on-demand” organization of brainstem vagal circuits may be one of the factors underlying the pathophysiological changes observed in functional dyspepsia or hyperglycemic gastroparesis. PMID:20804520

Relationship between vagal tone, cortisol, TNF-alpha, epinephrine and negative affects in Crohn's disease and irritable bowel syndrome.

PubMed

Pellissier, Sonia; Dantzer, Cécile; Mondillon, Laurie; Trocme, Candice; Gauchez, Anne-Sophie; Ducros, Véronique; Mathieu, Nicolas; Toussaint, Bertrand; Fournier, Alicia; Canini, Frédéric; Bonaz, Bruno

2014-01-01

Crohn's disease (CD) and irritable bowel syndrome (IBS) involve brain-gut dysfunctions where vagus nerve is an important component. The aim of this work was to study the association between vagal tone and markers of stress and inflammation in patients with CD or IBS compared to healthy subjects (controls). The study was performed in 73 subjects (26 controls, 21 CD in remission and 26 IBS patients). The day prior to the experiment, salivary cortisol was measured at 8:00 AM and 10:00 PM. The day of the experiment, subjects completed questionnaires for anxiety (STAI) and depressive symptoms (CES-D). After 30 min of rest, ECG was recorded for heart rate variability (HRV) analysis. Plasma cortisol, epinephrine, norepinephrine, TNF-alpha and IL-6 were measured in blood samples taken at the end of ECG recording. Compared with controls, CD and IBS patients had higher scores of state-anxiety and depressive symptomatology. A subgroup classification based on HRV-normalized high frequency band (HFnu) as a marker of vagal tone, showed that control subjects with high vagal tone had significantly lower evening salivary cortisol levels than subjects with low vagal tone. Such an effect was not observed in CD and IBS patients. Moreover, an inverse association (r =  -0.48; p<0.05) was observed between the vagal tone and TNF-alpha level in CD patients exclusively. In contrast, in IBS patients, vagal tone was inversely correlated with plasma epinephrine (r =  -0.39; p<0.05). No relationship was observed between vagal tone and IL-6, norepinephrine or negative affects (anxiety and depressive symptomatology) in any group. In conclusion, these data argue for an imbalance between the hypothalamus-pituitary-adrenal axis and the vagal tone in CD and IBS patients. Furthermore, they highlight the specific homeostatic link between vagal tone and TNF-alpha in CD and epinephrine in IBS and argue for the relevance of vagus nerve reinforcement interventions in those diseases.

The vagal nerve stimulation outcome, and laryngeal effect: Otolaryngologists roles and perspective.

PubMed

Al Omari, Ahmad I; Alzoubi, Firas Q; Alsalem, Mohammad M; Aburahma, Samah K; Mardini, Diala T; Castellanos, Paul F

Epilepsy is one of the most common neurologic disorders. Vagus nerve stimulation (VNS), first investigated in 1938 and subsequently studied as a potential therapy for epilepsy. The FDA approved the use of VNS in 1997 as an adjunctive non-pharmacologic symptomatic treatment option for refractory epilepsy for adults and adolescents over 12years. VNS can cause laryngeal and voice side effects that can be managed by otolaryngologists safely and effectively. This study is to review the outcomes of vagal nerve stimulator (VNS) implantation in terms of the surgical procedures, complications, seizure frequency, and the clinical effect on larynx and vocal folds motion. Series of thirty consecutive patients who had VNS implantation between 2007 and 2014 were recruited. Seizure-frequency outcome, surgical complications and device adverse effects of VNS were retrospectively reviewed. Additional evaluation included use of the Voice Handicap Index and Maximum Phonation Time (MPT) were conducted before and after the implantation. Videolaryngoscopy was used to evaluate the vocal fold mobility before and after the VNS implantation. Seizure frequency reduction over a minimum of 2years of follow up demonstrated: 100% in seizure frequency reduction in 1 patient, drastic reduction in seizure frequency (70-90%) in 9 patients, a good reduction in terms of seizure frequency (50%) in 8 patients, a 30% reduction in 5 patients, no response in 6 patients, and 1 patient had increased frequency. The most commonly reported adverse effects after VNS activation were coughing and voice changes with pitch breaks, as well as mild intermittent shortness of breath in 33% of patients. For those patients secondary supraglottic muscle tension and hyper function with reduced left vocal fold mobility were noticed on videolaryngoscopy, though none had aspiration problems. Surgical complications included a wound dehiscence in one patient (3%) which was surgically managed, minor intra-operative bleeding 3%; a

Effects of acute exercise on attenuated vagal baroreflex function during bed rest

NASA Technical Reports Server (NTRS)

Convertino, Victor A.; Doerr, Donald F.; Guell, Antonio; Marini, J.-F.

1992-01-01

We measured carotid baroreceptor-cardiac reflex responses in six healthy men, 24 h before and 24 h after a bout of leg exercise during 6 deg head-down bed rest to determine if depressed vagal baroreflex function associated with exposure to microgravity environments could be reversed by a single exposure to acute intense exercise. Baroreflex responses were measured before bed rest and on day 7 of bed rest. An exercise bout consisting of dynamic and isometric actions of the quadriceps at graded speeds and resistances was performed on day 8 of bed rest and measurements of baroreflex response were repeated 24 h later. Vagally-mediated cardiac responses were provoked with ramped neck pressure-suction sequences comprising pressure elevations to +40 mm Hg, followed by serial, R-wave triggered 15 mm Hg reductions, to -65 mm Hg. Baroreceptor stimulus-cardiac response relationships were derived by plotting each R-R interval as a function of systolic pressure less the neck chamber pressure applied during the interval. Compared with pre-bed rest baseline measurements, 7 d of bed rest decreased the gain (maximum slope) of the baroreflex stimulus-response relationship by 16.8 +/- 3.4 percent (p less than 0.05). On day 9 of bed rest, 24 h after exercise, the maximum slope of the baroreflex stimulus-response relationship was increased (p less than 0.05) by 10.7 +/- 3.7 percent above pre-bed rest levels and 34.3 +/- 7.9 percent above bed rest day 7. Our data verify that vagally-mediated baroreflex function is depressed by exposure to simulated microgravity and demonstrate that this effect can be acutely reversed by exposure to a single bout of intense exercise.

Modulation of gastrointestinal vagal neurocircuits by hyperglycemia

PubMed Central

Browning, Kirsteen N.

2013-01-01

Glucose sensing within autonomic neurocircuits is critical for the effective integration and regulation of a variety of physiological homeostatic functions including the co-ordination of vagally-mediated reflexes regulating gastrointestinal (GI) functions. Glucose regulates GI functions via actions at multiple sites of action, from modulating the activity of enteric neurons, endocrine cells, and glucose transporters within the intestine, to regulating the activity and responsiveness of the peripheral terminals, cell bodies and central terminals of vagal sensory neurons, to modifying both the activity and synaptic responsiveness of central brainstem neurons. Unsurprisingly, significant impairment in GI functions occurs in pathophysiological states where glucose levels are dysregulated, such as diabetes. A substantial obstacle to the development of new therapies to modify the disease, rather than treat the symptoms, are the gaps in our understanding of the mechanisms by which glucose modulates GI functions, particularly vagally-mediated responses and a more complete understanding of disease-related plasticity within these neurocircuits may open new avenues and targets for research. PMID:24324393

Relationship between Vagal Tone, Cortisol, TNF-Alpha, Epinephrine and Negative Affects in Crohn’s Disease and Irritable Bowel Syndrome

PubMed Central

Pellissier, Sonia; Dantzer, Cécile; Mondillon, Laurie; Trocme, Candice; Gauchez, Anne-Sophie; Ducros, Véronique; Mathieu, Nicolas; Toussaint, Bertrand; Fournier, Alicia; Canini, Frédéric; Bonaz, Bruno

2014-01-01

Crohn’s disease (CD) and irritable bowel syndrome (IBS) involve brain-gut dysfunctions where vagus nerve is an important component. The aim of this work was to study the association between vagal tone and markers of stress and inflammation in patients with CD or IBS compared to healthy subjects (controls). The study was performed in 73 subjects (26 controls, 21 CD in remission and 26 IBS patients). The day prior to the experiment, salivary cortisol was measured at 8∶00 AM and 10∶00 PM. The day of the experiment, subjects completed questionnaires for anxiety (STAI) and depressive symptoms (CES-D). After 30 min of rest, ECG was recorded for heart rate variability (HRV) analysis. Plasma cortisol, epinephrine, norepinephrine, TNF-alpha and IL-6 were measured in blood samples taken at the end of ECG recording. Compared with controls, CD and IBS patients had higher scores of state-anxiety and depressive symptomatology. A subgroup classification based on HRV-normalized high frequency band (HFnu) as a marker of vagal tone, showed that control subjects with high vagal tone had significantly lower evening salivary cortisol levels than subjects with low vagal tone. Such an effect was not observed in CD and IBS patients. Moreover, an inverse association (r = −0.48; p<0.05) was observed between the vagal tone and TNF-alpha level in CD patients exclusively. In contrast, in IBS patients, vagal tone was inversely correlated with plasma epinephrine (r = −0.39; p<0.05). No relationship was observed between vagal tone and IL-6, norepinephrine or negative affects (anxiety and depressive symptomatology) in any group. In conclusion, these data argue for an imbalance between the hypothalamus-pituitary-adrenal axis and the vagal tone in CD and IBS patients. Furthermore, they highlight the specific homeostatic link between vagal tone and TNF-alpha in CD and epinephrine in IBS and argue for the relevance of vagus nerve reinforcement interventions in those diseases. PMID

Exposure to a high fat diet during the perinatal period alters vagal motoneurone excitability, even in the absence of obesity

PubMed Central

Bhagat, Ruchi; Fortna, Samuel R; Browning, Kirsteen N

2015-01-01

The perinatal period is critically important to the development of autonomic neural circuits responsible for energy homeostasis. Vagal neurocircuits are vital to the regulation of upper gastrointestinal functions, including satiety. Diet-induced obesity modulates the excitability and responsiveness of both peripheral vagal afferents and central vagal efferents but less information is available regarding the effects of diet per se on vagal neurocircuit functions. The aims of this study were to investigate whether perinatal exposure to a high fat diet (HFD) dysregulated dorsal motor nucleus of the vagus (DMV) neurones, prior to the development of obesity. Whole cell patch clamp recordings were made from gastric-projecting DMV neurones in thin brainstem slices from rats that were exposed to either a control diet or HFD from pregnancy day 13. Our data demonstrate that following perinatal HFD: (i) DMV neurones had decreased excitability and input resistance with a reduced ability to fire action potentials; (ii) the proportion of DMV neurones excited by cholecystokinin (CCK) was unaltered but the proportion of neurones in which CCK increased excitatory glutamatergic synaptic inputs was reduced; (iii) the tonic activation of presynaptic group II metabotropic glutamate receptors on inhibitory nerve terminals was attenuated, allowing modulation of GABAergic synaptic transmission; and (iv) the size and dendritic arborization of gastric-projecting DMV neurones was increased. These results suggest that perinatal HFD exposure compromises the excitability and responsiveness of gastric-projecting DMV neurones, even in the absence of obesity, suggesting that attenuation of vago-vagal reflex signalling may precede the development of obesity. PMID:25556801

Sympathetic restraint of respiratory sinus arrhythmia: implications for vagal-cardiac tone assessment in humans

NASA Technical Reports Server (NTRS)

Taylor, J. A.; Myers, C. W.; Halliwill, J. R.; Seidel, H.; Eckberg, D. L.

2001-01-01

Clinicians and experimentalists routinely estimate vagal-cardiac nerve traffic from respiratory sinus arrhythmia. However, evidence suggests that sympathetic mechanisms may also modulate respiratory sinus arrhythmia. Our study examined modulation of respiratory sinus arrhythmia by sympathetic outflow. We measured R-R interval spectral power in 10 volunteers that breathed sequentially at 13 frequencies, from 15 to 3 breaths/min, before and after beta-adrenergic blockade. We fitted changes of respiratory frequency R-R interval spectral power with a damped oscillator model: frequency-dependent oscillations with a resonant frequency, generated by driving forces and modified by damping influences. beta-Adrenergic blockade enhanced respiratory sinus arrhythmia at all frequencies (at some, fourfold). The damped oscillator model fit experimental data well (39 of 40 ramps; r = 0.86 +/- 0.02). beta-Adrenergic blockade increased respiratory sinus arrhythmia by amplifying respiration-related driving forces (P < 0.05), without altering resonant frequency or damping influences. Both spectral power data and the damped oscillator model indicate that cardiac sympathetic outflow markedly reduces heart period oscillations at all frequencies. This challenges the notion that respiratory sinus arrhythmia is mediated simply by vagal-cardiac nerve activity. These results have important implications for clinical and experimental estimation of human vagal cardiac tone.

Disrupting vagal feedback affects birdsong motor control.

PubMed

Méndez, Jorge M; Dall'asén, Analía G; Goller, Franz

2010-12-15

Coordination of different motor systems for sound production involves the use of feedback mechanisms. Song production in oscines is a well-established animal model for studying learned vocal behavior. Whereas the online use of auditory feedback has been studied in the songbird model, very little is known about the role of other feedback mechanisms. Auditory feedback is required for the maintenance of stereotyped adult song. In addition, the use of somatosensory feedback to maintain pressure during song has been demonstrated with experimentally induced fluctuations in air sac pressure. Feedback information mediating this response is thought to be routed to the central nervous system via afferent fibers of the vagus nerve. Here, we tested the effects of unilateral vagotomy on the peripheral motor patterns of song production and the acoustic features. Unilateral vagotomy caused a variety of disruptions and alterations to the respiratory pattern of song, some of which affected the acoustic structure of vocalizations. These changes were most pronounced a few days after nerve resection and varied between individuals. In the most extreme cases, the motor gestures of respiration were so severely disrupted that individual song syllables or the song motif were atypically terminated. Acoustic changes also suggest altered use of the two sound generators and upper vocal tract filtering, indicating that the disruption of vagal feedback caused changes to the motor program of all motor systems involved in song production and modification. This evidence for the use of vagal feedback by the song system with disruption of song during the first days after nerve cut provides a contrast to the longer-term effects of auditory feedback disruption. It suggests a significant role for somatosensory feedback that differs from that of auditory feedback.

Disrupting vagal feedback affects birdsong motor control

PubMed Central

Méndez, Jorge M.; Dall'Asén, Analía G.; Goller, Franz

2010-01-01

Coordination of different motor systems for sound production involves the use of feedback mechanisms. Song production in oscines is a well-established animal model for studying learned vocal behavior. Whereas the online use of auditory feedback has been studied in the songbird model, very little is known about the role of other feedback mechanisms. Auditory feedback is required for the maintenance of stereotyped adult song. In addition, the use of somatosensory feedback to maintain pressure during song has been demonstrated with experimentally induced fluctuations in air sac pressure. Feedback information mediating this response is thought to be routed to the central nervous system via afferent fibers of the vagus nerve. Here, we tested the effects of unilateral vagotomy on the peripheral motor patterns of song production and the acoustic features. Unilateral vagotomy caused a variety of disruptions and alterations to the respiratory pattern of song, some of which affected the acoustic structure of vocalizations. These changes were most pronounced a few days after nerve resection and varied between individuals. In the most extreme cases, the motor gestures of respiration were so severely disrupted that individual song syllables or the song motif were atypically terminated. Acoustic changes also suggest altered use of the two sound generators and upper vocal tract filtering, indicating that the disruption of vagal feedback caused changes to the motor program of all motor systems involved in song production and modification. This evidence for the use of vagal feedback by the song system with disruption of song during the first days after nerve cut provides a contrast to the longer-term effects of auditory feedback disruption. It suggests a significant role for somatosensory feedback that differs from that of auditory feedback. PMID:21113000

Adverse Effects and Surgical Complications in Pediatric Patients Undergoing Vagal Nerve Stimulation for Drug-Resistant Epilepsy.

PubMed

Trezza, A; Landi, A; Grioni, D; Pirillo, D; Fiori, L; Giussani, C; Sganzerla, E P

2017-01-01

Vagal nerve stimulation (VNS) is an effective treatment for drug-resistant epilepsy that is not suitable for resective surgery, both in adults and in children. Few reports describe the adverse effects and complications of VNS. The aim of our study was to present a series of 33 pediatric patients who underwent VNS for drug-resistant epilepsy and to discuss the adverse effects and complications through a review of the literature.The adverse effects of VNS are usually transient and are dependent on stimulation of the vagus and its efferent fibers; surgical complications of the procedure may be challenging and patients sometimes require further surgery; generally these complications affect VNS efficacy; in addition, hardware complications also have to be taken into account.In our experience and according to the literature, adverse effects and surgical and hardware complications are uncommon and can usually be managed definitely. Careful selection of patients, particularly from a respiratory and cardiac point of view, has to be done before surgery to limit the incidence of some adverse effects.

Chronic implantation of cuff electrodes on the pelvic nerve in rats is well tolerated and does not compromise afferent or efferent fibre functionality

NASA Astrophysics Data System (ADS)

Crook, J. J.; Brouillard, C. B. J.; Irazoqui, P. P.; Lovick, T. A.

2018-04-01

Objective. Neuromodulation of autonomic nerve activity to regulate physiological processes is an emerging field. Vagal stimulation has received most attention whereas the potential of modulate visceral function by targeting autonomic nerves within the abdominal cavity remains under-exploited. Surgery to locate intra-abdominal targets is inherently more stressful than for peripheral nerves. Electrode leads risk becoming entrapped by intestines and loss of functionality in the nerve-target organ connection could result from electrode migration or twisting. Since nociceptor afferents are intermingled with similar-sized visceral autonomic fibres, stimulation may induce pain. In anaesthetised rats high frequency stimulation of the pelvic nerve can suppress urinary voiding but it is not known how conscious animals would react to this procedure. Our objective therefore was to determine how rats tolerated chronic implantation of cuff electrodes on the pelvic nerve, whether nerve stimulation would be aversive and whether nerve-bladder functionality would be compromised. Approach. We carried out a preliminary de-risking study to investigate how conscious rats tolerated chronic implantation of electrodes on the pelvic nerve, their responsiveness to intermittent high frequency stimulation and whether functionality of the nerve-bladder connection became compromised. Main results. Implantation of cuff electrodes was well-tolerated. The normal diurnal pattern of urinary voiding was not disrupted. Pelvic nerve stimulation (up to 4 mA, 3 kHz) for 30 min periods evoked mild alerting at stimulus onset but no signs of pain. Stimulation evoked a modest (<0.5 °C) increase in nerve temperature but the functional integrity of the nerve-bladder connection, reflected by contraction of the detrusor muscle in response to 10 Hz nerve stimulation, was not compromised. Significance. Chronic implantation of cuff electrodes on the pelvic nerve was found to be a well-tolerated procedure in

Radiofrequency Catheter Ablation for Atrial Fibrillation Elicited "Jackhammer Esophagus": A New Complication Due to Vagal Nerve Stimulation?

PubMed

Tolone, Salvatore; Savarino, Edoardo; Docimo, Ludovico

2015-10-01

Radiofrequency catheter ablation (RFCA) is a potentially curative method for treatment of highly symptomatic and drug-refractory atrial fibrillation (AF). However, this technique can provoke esophageal and nerve lesion, due to thermal injury. To our knowledge, there have been no reported cases of a newly described motor disorder, the Jackhammer esophagus (JE) after RFCA, independently of GERD. We report a case of JE diagnosed by high-resolution manometry (HRM), in whom esophageal symptoms developed 2 weeks after RFCA, in absence of objective evidence of GERD. A 65-year-old male with highly symptomatic, drug-refractory paroxysmal AF was candidate to complete electrical pulmonary vein isolation with RFCA. Prior the procedure, the patient underwent HRM and impedance-pH to rule out GERD or hiatal hernia presence. All HRM parameters, according to Chicago classification, were within normal limits. No significant gastroesophageal reflux was documented at impedance pH monitoring. Patient underwent RFCA with electrical disconnection of pulmonary vein. After two weeks, patient started to complain of dysphagia for solids, with acute chest-pain. The patient repeated HRM and impedance-pH monitoring 8 weeks after RFCA. HRM showed in all liquid swallows the typical spastic hypercontractile contractions consistent with the diagnosis of JE, whereas impedance-pH monitoring resulted again negative for GERD. Esophageal dysmotility can represent a possible complication of RFCA for AF, probably due to a vagal nerve injury, and dysphagia appearance after this procedure must be timely investigated by HRM.

Deletion of neurturin impairs development of cholinergic nerves and heart rate control in postnatal mouse hearts.

PubMed

Downs, Anthony M; Jalloh, Hawa B; Prater, Kayla J; Fregoso, Santiago P; Bond, Cherie E; Hampton, Thomas G; Hoover, Donald B

2016-05-01

The neurotrophic factor neurturin is required for normal cholinergic innervation of adult mouse heart and bradycardic responses to vagal stimulation. Our goals were to determine effects of neurturin deletion on development of cardiac chronotropic and dromotropic functions, vagal baroreflex response, and cholinergic nerve density in nodal regions of postnatal mice. Experiments were performed on postnatal C57BL/6 wild-type (WT) and neurturin knockout (KO) mice. Serial electrocardiograms were recorded noninvasively from conscious pups using an ECGenie apparatus. Mice were treated with atenolol to evaluate and block sympathetic effects on heart rate (HR) and phenylephrine (PE) to stimulate the baroreflex. Immunohistochemistry was used to label cholinergic nerves in paraffin sections. WT and KO mice showed similar age-dependent increases in HR and decreases in PR interval between postnatal days (P) 2.5 and 21. Treatment with atenolol reduced HR significantly in WT and KO pups at P7.5. PE caused a reflex bradycardia that was significantly smaller in KO pups. Cholinergic nerve density was significantly less in nodal regions of P7.5 KO mice. We conclude that cholinergic nerves have minimal influence on developmental changes in HR and PR, QRS, and QTc intervals in mouse pups. However, cholinergic nerves mediate reflex bradycardia by 1 week postnatally. Deletion of neurturin impairs cholinergic innervation of the heart and the vagal efferent component of the baroreflex early during postnatal development. © 2016 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

Different role of TTX-sensitive voltage-gated sodium channel (NaV 1) subtypes in action potential initiation and conduction in vagal airway nociceptors.

PubMed

Kollarik, M; Sun, H; Herbstsomer, R A; Ru, F; Kocmalova, M; Meeker, S N; Undem, B J

2018-04-15

The action potential initiation in the nerve terminals and its subsequent conduction along the axons of afferent nerves are not necessarily dependent on the same voltage-gated sodium channel (Na V 1) subunits. The action potential initiation in jugular C-fibres within airway tissues is not blocked by TTX; nonetheless, conduction of action potentials along the vagal axons of these nerves is often dependent on TTX-sensitive channels. This is not the case for nodose airway Aδ-fibres and C-fibres, where both action potential initiation and conduction is abolished by TTX or selective Na V 1.7 blockers. The difference between the initiation of action potentials within the airways vs. conduction along the axons should be considered when developing Na V 1 blocking drugs for topical application to the respiratory tract. The action potential (AP) initiation in the nerve terminals and its subsequent AP conduction along the axons do not necessarily depend on the same subtypes of voltage-gated sodium channels (Na V 1s). We evaluated the role of TTX-sensitive and TTX-resistant Na V 1s in vagal afferent nociceptor nerves derived from jugular and nodose ganglia innervating the respiratory system. Single cell RT-PCR was performed on vagal afferent neurons retrogradely labelled from the guinea pig trachea. Almost all of the jugular neurons expressed the TTX-sensitive channel Na V 1.7 along with TTX-resistant Na V 1.8 and Na V 1.9. Tracheal nodose neurons also expressed Na V 1.7 but, less frequently, Na V 1.8 and Na V 1.9. Na V 1.6 were expressed in ∼40% of the jugular and 25% of nodose tracheal neurons. Other Na V 1 α subunits were only rarely expressed. Single fibre recordings were made from the vagal nodose and jugular nerve fibres innervating the trachea or lung in the isolated perfused vagally-innervated preparations that allowed for selective drug delivery to the nerve terminal compartment (AP initiation) or to the desheathed vagus nerve (AP conduction). AP initiation in

Plasticity of gastrointestinal vagal afferent satiety signals.

PubMed

Page, A J; Kentish, S J

2017-05-01

The vagal link between the gastrointestinal tract and the central nervous system (CNS) has numerous vital functions for maintaining homeostasis. The regulation of energy balance is one which is attracting more and more attention due to the potential for exploiting peripheral hormonal targets as treatments for conditions such as obesity. While physiologically, this system is well tuned and demonstrated to be effective in the regulation of both local function and promoting/terminating food intake the neural connection represents a susceptible pathway for disruption in various disease states. Numerous studies have revealed that obesity in particularly is associated with an array of modifications in vagal afferent function from changes in expression of signaling molecules to altered activation mechanics. In general, these changes in vagal afferent function in obesity further promote food intake instead of the more desirable reduction in food intake. It is essential to gain a comprehensive understanding of the mechanisms responsible for these detrimental effects before we can establish more effective pharmacotherapies or lifestyle strategies for the treatment of obesity and the maintenance of weight loss. © 2016 John Wiley & Sons Ltd.

Coexistence of calbindin D-28k and NADPH-diaphorase in vagal and glossopharyngeal sensory neurons of the rat.

PubMed

Ichikawa, H; Helke, C J

1996-10-07

The presence and coexistence of calbindin D-28k-immunoreactivity (ir) and nicotinamide adenosine dinucleotide phosphate (NADPH)-diaphorase activity (a marker of neurons that are presumed to convert L-arginine to L-citrulline and nitric oxide) were examined in the glossopharyngeal and vagal sensory ganglia (jugular, petrosal and nodose ganglia) of the rat. Calbindin D-28k-ir nerve cells were found in moderate and large numbers in the petrosal and nodose ganglia, respectively. Some calbindin D-28k-ir nerve cells were also observed in the jugular ganglion. NADPH-diaphorase positive nerve cells were localized to the jugular and nodose ganglia and were rare in the petrosal ganglion. A considerable portion (33-51%) of the NADPH-diaphorase positive neurons in these ganglia colocalized calbindin D-28k-ir. The presence and colocalization of calbindin D-28k-ir and NADPH-diaphorase activity in neurotransmitter-identified subpopulations of visceral sensory neurons were also studied. In all three ganglia, calcitonin gene-related peptide (CGRP)-ir was present in many NADPH-diaphorase positive neurons, a subset of which also contained calbindin D-28k-ir. In the nodose ganglion, many (42%) of tyrosine hydroxylase (TH)-ir neurons also contained NADPH diaphorase activity but did not contain calbindin D-28k-ir. These data are consistent with a potential co-operative role for calbindin D-28k and NADPH-diaphorase in the functions of a subpopulation of vagal and glossopharyngeal sensory neurons.

Effect of vagal stimulation on gastric mucosal barrier in albino rats.

PubMed

Somasundaram, K; Ganguly, A K

1987-01-01

To study the influence of vagus nerves on gastric mucosal barrier in albino rats, gastric adherent mucus and mucosal epithelial neutral glycoproteins were quantitatively assessed after vagal stimulation at the cardio-esophageal region by a specially designed circular electrode. Gastric adherent mucus and epithelial mucus were studied from oxyntic and pyloric gland areas by Alcian blue binding and periodic acid Schiff's (PAS) staining method respectively. The results when compared with sham operated control animals showed increase in the visible mucus concurrent with decrease in PAS positive materials. The stimulation at the cardio-esophageal region of vagotomized animals did not produce these effects. This study indicates that in an acute condition, increased vagal influence is important in increasing mucus secretion and strengthening the first line of defence of the mucosal barrier.

Cardiac vagal control and children’s adaptive functioning: A meta-analysis

PubMed Central

Graziano, Paulo; Derefinko, Karen

2014-01-01

Polyvagal theory has influenced research on the role of cardiac vagal control, indexed by respiratory sinus arrhythmia withdrawal (RSA-W) during challenging states, in children’s self-regulation. However, it remains unclear how well RSA-W predicts adaptive functioning (AF) outcomes and whether certain caveats of measuring RSA (e.g., respiration) significantly impact these associations. A meta-analysis of 44 studies (n = 4,996 children) revealed small effect sizes such that greater levels of RSA-W were related to fewer externalizing, internalizing, and cognitive/academic problems. In contrast, RSA-W was differentially related to children’s social problems according to sample type (community vs. clinical/at-risk). The relations between RSA-W and children’s AF outcomes were stronger among studies that co-varied baseline RSA and in Caucasian children (no effect was found for respiration). Children from clinical/at-risk samples displayed lower levels of baseline RSA and RSA-W compared to children from community samples. Theoretical/practical implications for the study of cardiac vagal control are discussed. PMID:23648264

Influence of microgravity on astronauts' sympathetic and vagal responses to Valsalva's manoeuvre

NASA Technical Reports Server (NTRS)

Cox, James F.; Tahvanainen, Kari U O.; Kuusela, Tom A.; Levine, Benjamin D.; Cooke, William H.; Mano, Tadaaki; Iwase, Satoshi; Saito, Mitsuru; Sugiyama, Yoshiki; Ertl, Andrew C.;

Exposure to a high fat diet during the perinatal period alters vagal motoneurone excitability, even in the absence of obesity.

PubMed

Bhagat, Ruchi; Fortna, Samuel R; Browning, Kirsteen N

2015-01-01

Obesity is recognized as being multifactorial in origin, involving both genetic and environmental factors. The perinatal period is known to be critically important in the development of neural circuits responsible for energy homeostasis and the integration of autonomic reflexes. Diet-induced obesity alters the biophysical, pharmacological and morphological properties of vagal neurocircuits regulating upper gastrointestinal tract functions, including satiety. Less information is available, however, regarding the effects of a high fat diet (HFD) itself on the properties of vagal neurocircuits. The present study was designed to test the hypothesis that exposure to a HFD during the perinatal period alters the electrophysiological, pharmacological and morphological properties of vagal efferent motoneurones innervating the stomach. Our data indicate that perinatal HFD decreases the excitability of gastric-projecting dorsal motor nucleus neurones and dysregulates neurotransmitter release from synaptic inputs and that these alterations occur prior to the development of obesity. These findings represent the first direct evidence that exposure to a HFD modulates the processing of central vagal neurocircuits even in the absence of obesity. The perinatal period is critically important to the development of autonomic neural circuits responsible for energy homeostasis. Vagal neurocircuits are vital to the regulation of upper gastrointestinal functions, including satiety. Diet-induced obesity modulates the excitability and responsiveness of both peripheral vagal afferents and central vagal efferents but less information is available regarding the effects of diet per se on vagal neurocircuit functions. The aims of this study were to investigate whether perinatal exposure to a high fat diet (HFD) dysregulated dorsal motor nucleus of the vagus (DMV) neurones, prior to the development of obesity. Whole cell patch clamp recordings were made from gastric-projecting DMV neurones in thin

Resection of cervical vagal schwannoma via a post-auricular approach.

PubMed

Roh, Jong-Lyel

2006-03-01

Cervical vagal schwannomas are extremely rare and gross total resection is the standard treatment modality. However, because the conventional cervical approach leaves an incision scar in a visible area, other approaches need to be developed for young women who want the postoperative scar to be invisible. A 28-year-old female underwent complete resection of a 4x4 cm tumor in her right upper neck via a post-auricular approach using an inverted V-shaped incision along the post-auricular sulcus and hairline. The tumor was a schwannoma originating from the right cervical vagus nerve. Postoperatively, right vocal cord paralysis developed despite careful dissection but completely recovered within 6 months after surgery. The patient was satisfied with an invisible external scar which was hidden by her auricle and hair. A cervical vagal schwannoma can be successfully removed by making an incision in a potentially invisible area.

Pulmonary vein region ablation in experimental vagal atrial fibrillation: role of pulmonary veins versus autonomic ganglia.

PubMed

Lemola, Kristina; Chartier, Denis; Yeh, Yung-Hsin; Dubuc, Marc; Cartier, Raymond; Armour, Andrew; Ting, Michael; Sakabe, Masao; Shiroshita-Takeshita, Akiko; Comtois, Philippe; Nattel, Stanley

2008-01-29

Pulmonary vein (PV) -encircling radiofrequency ablation frequently is effective in vagal atrial fibrillation (AF), and there is evidence that PVs may be particularly prone to cholinergically induced arrhythmia mechanisms. However, PV ablation procedures also can affect intracardiac autonomic ganglia. The present study examined the relative role of PVs versus peri-PV autonomic ganglia in an experimental vagal AF model. Cholinergic AF was studied under carbachol infusion in coronary perfused canine left atrial PV preparations in vitro and with cervical vagal stimulation in vivo. Carbachol caused dose-dependent AF promotion in vitro, which was not affected by excision of all PVs. Sustained AF could be induced easily in all dogs during vagal nerve stimulation in vivo both before and after isolation of all PVs with encircling lesions created by a bipolar radiofrequency ablation clamp device. PV elimination had no effect on atrial effective refractory period or its responses to cholinergic stimulation. Autonomic ganglia were identified by bradycardic and/or tachycardic responses to high-frequency subthreshold local stimulation. Ablation of the autonomic ganglia overlying all PV ostia suppressed the effective refractory period-abbreviating and AF-promoting effects of cervical vagal stimulation, whereas ablation of only left- or right-sided PV ostial ganglia failed to suppress AF. Dominant-frequency analysis suggested that the success of ablation in suppressing vagal AF depended on the elimination of high-frequency driver regions. Intact PVs are not needed for maintenance of experimental cholinergic AF. Ablation of the autonomic ganglia at the base of the PVs suppresses vagal responses and may contribute to the effectiveness of PV-directed ablation procedures in vagal AF.

Effects of gastric distension and infusion of umami and bitter taste stimuli on vagal afferent activity.

PubMed

Horn, Charles C; Murat, Chloé; Rosazza, Matthew; Still, Liz

2011-10-24

Until recently, sensory nerve pathways from the stomach to the brain were thought to detect distension and play little role in nutritional signaling. Newer data have challenged this view, including reports on the presence of taste receptors in the gastrointestinal lumen and the stimulation of multi-unit vagal afferent activity by glutamate infusions into the stomach. However, assessing these chemosensory effects is difficult because gastric infusions typically evoke a distension-related vagal afferent response. In the current study, we recorded gastric vagal afferent activity in the rat to investigate the possibility that umami (glutamate, 150 mM) and bitter (denatonium, 10 mM) responses could be dissociated from distension responses by adjusting the infusion rate and opening or closing the drainage port in the stomach. Slow infusions of saline (5 ml over 2 min, open port) produced no significant effects on vagal activity. Using the same infusion rate, glutamate or denatonium solutions produced little or no effects on vagal afferent activity. In an attempt to reproduce a prior report that showed distention and glutamate responses, we produced a distension response by closing the exit port. Under this condition, response to the infusion of glutamate or denatonium was similar to saline. In summary, we found little or no effect of gastric infusion of glutamate or denatonium on gastric vagal afferent activity that could be distinguished from distension responses. The current results suggest that sensitivity to umami or bitter stimuli is not a common property of gastric vagal afferent fibers. Copyright © 2011 Elsevier B.V. All rights reserved.

Therapeutic effects of selective atrioventricular node vagal stimulation in atrial fibrillation and heart failure.

PubMed

Zhang, Youhua; Popović, Zoran B; Kusunose, Kenya; Mazgalev, Todor N

2013-01-01

Atrial fibrillation (AF) and heart failure (HF) frequently coexist. We have previously demonstrated that selective atrioventricular node (AVN) vagal stimulation (AVN-VS) can be used to control ventricular rate during AF. Due to withdrawal of vagal activity in HF, the therapeutic effects of AVN-VS may be compromised in the combined condition of AF and HF. Accordingly, this study was designed to evaluate the therapeutic effects of AVN-VS to control ventricular rate in AF and HF. A combined model of AF and HF was created by implanting a dual chamber pacemaker in 24 dogs. A newly designed bipolar electrode was inserted into the ganglionic AVN fat pad and connected to a nerve stimulator for delivering AVN-VS. In all dogs, HF was induced by high rate ventricular pacing at 220 bpm for 4 weeks. AF was then induced and maintained by rapid atrial pacing at 600 bpm after discontinuation of ventricular pacing. These HF + AF dogs were randomized into control (n = 9) and AVN-VS (n = 15) groups. In the latter group, vagal stimulation (310 μs, 20 Hz, 3-7 mA) was delivered continuously for 6 months. Compared with the control, AVN-VS had a consistent effect on ventricular rate slowing (by >50 bpm, all P < 0.001) during the entire 6-month observation period that was associated with left ventricular functional improvement. Moreover, AVN-VS was well tolerated by the treated animals. AVN-VS achieved consistent rate slowing, which was associated with improved ventricular function in a canine AF and HF model. Thus, AVN-VS may be a novel, effective therapeutic option in the combined condition of AF and HF. © 2012 Wiley Periodicals, Inc.

Chronic Sarpogrelate Treatment Reveals 5-HT7 Receptor in the Serotonergic Inhibition of the Rat Vagal Bradycardia.

PubMed

García-Pedraza, José Ángel; García, Mónica; Martín, María Luisa; Eleno, Nélida; Morán, Asunción

2017-01-01

5-Hydroxytryptamine (5-HT) modulates the cardiac parasympathetic neurotransmission, inhibiting the bradyarrhythmia by 5-HT2 receptor activation. We aimed to determine whether the chronic selective 5-HT2 blockade (sarpogrelate) could modify the serotonergic modulation on vagal cardiac outflow in pithed rat. Bradycardic responses in rats treated with sarpogrelate (30 mg·kg·d; orally) were obtained by electrical stimulation of the vagal fibers (3, 6, and 9 Hz) or intravenous (IV) injections of acetylcholine (1, 5, and 10 μg/kg). 5-HT7 receptor expression was quantified by Western blot in vagus nerve and right atrium. The IV administration of 5-HT (10-200 μg/kg) dose dependently decreased the vagally induced bradycardia, and agonists 5-CT (5-HT1/7), 8-OH-DPAT (5-HT1A), or AS-19 (5-HT7) (50 μg/kg each) mimicked the 5-HT-induced inhibitory effect. Neither agonists CGS-12066B (5-HT1B), L-694,247 (5-HT1D), nor 1-phenylbiguanide (5-HT3) modified the electrically-induced bradycardic responses. Moreover, SB-258719 (5-HT7 antagonist) abolished the 5-HT-, 5-CT-, 8-OH-DPAT-, and AS-19-induced bradycardia inhibition; 5-HT or AS-19 did not modify the bradycardia induced by IV acetylcholine; and 5-HT7 receptor was expressed in both the vagus nerve and the right atrium. Our outcomes suggest that blocking chronically 5-HT2 receptors modifies the serotonergic influence on cardiac vagal neurotransmission exhibiting 5-HT as an exclusively inhibitory agent via prejunctional 5-HT7 receptor.

The role of the vagus nerve in the generation of cardiorespiratory interactions in a neotropical fish, the pacu, Piaractus mesopotamicus.

PubMed

Leite, Cleo Alcantara Costa; Taylor, E W; Guerra, C D R; Florindo, L H; Belão, T; Rantin, F T

2009-08-01

The role of the vagus nerve in determining heart rate (f(H)) and cardiorespiratory interactions was investigated in a neotropical fish, Piaractus mesopotamicus. During progressive hypoxia f(H) initially increased, establishing a 1:1 ratio with ventilation rate (f(R)). Subsequently there was a hypoxic bradycardia. Injection of atropine abolished a normoxic inhibitory tonus on the heart and the f(H) adjustments during progressive hypoxia, confirming that they are imposed by efferent parasympathetic inputs via the vagus nerve. Efferent activity recorded from the cardiac vagus in lightly anesthetized normoxic fish included occasional bursts of activity related to spontaneous changes in ventilation amplitude, which increased the cardiac interval. Restricting the flow of aerated water irrigating the gills resulted in increased respiratory effort and bursts of respiration-related activity in the cardiac vagus that seemed to cause f(H) to couple with f(R). Cell bodies of cardiac vagal pre-ganglionic neurons were located in two distinct groups within the dorsal vagal motor column having an overlapping distribution with respiratory motor-neurons. A small proportion of cardiac vagal pre-ganglionic neurons (2%) was in scattered positions in the ventrolateral medulla. This division of cardiac vagal pre-ganglionic neurons into distinct motor groups may relate to their functional roles in determining cardiorespiratory interactions.

The modulatory effects of noradrenaline on vagal control of heart rate in the dogfish, Squalus acanthias.

PubMed

Agnisola, Claudio; Randall, David J; Taylor, Edwin W

2003-01-01

The possible interactions between inhibitory vagal control of the heart and circulating levels of catecholamines in dogfish (Squalus acanthias) were studied using an in situ preparation of the heart, which retained intact its innervation from centrally cut vagus nerves. The response to peripheral vagal stimulation typically consisted of an initial cardiac arrest, followed by an escape beat, leading to renewed beating at a mean heart rate lower than the prestimulation rate (partial recovery). Cessation of vagal stimulation led to a transient increase in heart rate, above the prestimulation rate. This whole response was completely abolished by 10(-4) M atropine (a muscarinic cholinergic antagonist). The degree of vagal inhibition was evaluated in terms of both the initial, maximal cardiac interval and the mean heart rate during partial recovery, both expressed as a percentage of the prestimulation heart rate. The mean prestimulation heart rate of this preparation (36+/-4 beats min(-1)) was not affected by noradrenaline but was significantly reduced by 10(-4) M nadolol (a beta-adrenergic receptor antagonist), suggesting the existence of a resting adrenergic tone arising from endogenous catecholamines. The degree of vagal inhibition of heart rate varied with the rate of stimulation and was increased by the presence of 10(-8) M noradrenaline (the normal in vivo level in routinely active fish), while 10(-7) M noradrenaline (the in vivo level measured in disturbed or deeply hypoxic fish) reduced the cardiac response to vagal stimulation. In the presence of 10(-7) M noradrenaline, 10(-4) M nadolol further reduced the vagal response, while 10(-4) M nadolol + 10(-4) M phentolamine had no effect, indicating a complex interaction between adrenoreceptors, possibly involving presynaptic modulation of vagal inhibition.

Sensation, mechanoreceptor, and nerve fiber function after nerve regeneration.

PubMed

Krarup, Christian; Rosén, Birgitta; Boeckstyns, Michel; Ibsen Sørensen, Allan; Lundborg, Göran; Moldovan, Mihai; Archibald, Simon J

2017-12-01

Sensation is essential for recovery after peripheral nerve injury. However, the relationship between sensory modalities and function of regenerated fibers is uncertain. We have investigated the relationships between touch threshold, tactile gnosis, and mechanoreceptor and sensory fiber function after nerve regeneration. Twenty-one median or ulnar nerve lesions were repaired by a collagen nerve conduit or direct suture. Quantitative sensory hand function and sensory conduction studies by near-nerve technique, including tactile stimulation of mechanoreceptors, were followed for 2 years, and results were compared to noninjured hands. At both repair methods, touch thresholds at the finger tips recovered to 81 ± 3% and tactile gnosis only to 20 ± 4% (p < 0.001) of control. The sensory nerve action potentials (SNAPs) remained dispersed and areas recovered to 23 ± 2% and the amplitudes only to 7 ± 1% (P < 0.001). The areas of SNAPs after tactile stimulation recovered to 61 ± 11% and remained slowed. Touch sensation correlated with SNAP areas (p < 0.005) and was negatively related to the prolongation of tactile latencies (p < 0.01); tactile gnosis was not related to electrophysiological parameters. The recovered function of regenerated peripheral nerve fibers and reinnervated mechanoreceptors may differentially influence recovery of sensory modalities. Touch was affected by the number and function of regenerated fibers and mechanoreceptors. In contrast, tactile gnosis depends on the input and plasticity of the central nervous system (CNS), which may explain the absence of a direct relation between electrophysiological parameters and poor recovery. Dispersed maturation of sensory nerve fibers with desynchronized inputs to the CNS also contributes to the poor recovery of tactile gnosis. Ann Neurol 2017. Ann Neurol 2017;82:940-950. © 2017 American Neurological Association.

High Ulnar Nerve Injuries: Nerve Transfers to Restore Function.

PubMed

Patterson, Jennifer Megan M

2016-05-01

Peripheral nerve injuries are challenging problems. Nerve transfers are one of many options available to surgeons caring for these patients, although they do not replace tendon transfers, nerve graft, or primary repair in all patients. Distal nerve transfers for the treatment of high ulnar nerve injuries allow for a shorter reinnervation period and improved ulnar intrinsic recovery, which are critical to function of the hand. Copyright © 2016 Elsevier Inc. All rights reserved.

Evidence for a vagal pathophysiology for bulimia nervosa and the accompanying depressive symptoms.

PubMed

Faris, Patricia L; Eckert, Elke D; Kim, Suck-Won; Meller, William H; Pardo, Jose V; Goodale, Robert L; Hartman, Boyd K

2006-05-01

The bilateral vagus nerves (Cranial X) provide both afferent and efferent connections between the viscera and the caudal medulla. The afferent branches increasingly are being recognized as providing significant input to the central nervous system for modulation of complex behaviors. In this paper, we review evidence from our laboratory that increases in vagal afferent activity are involved in perpetuating binge-eating and vomiting in bulimia nervosa. Preliminary findings are also presented which suggest that a subgroup of depressions may have a similar pathophysiology. Two main approaches were used to study the role of vagal afferents. Ondansetron (ONDAN), a 5-HT3 antagonist, was used as a pharmacological tool for inhibiting or reducing vagal afferent neurotransmission. Second, somatic pain detection thresholds were assessed for monitoring a physiological process known to be modulated by vagal afferents, including the gastric branches involved in meal termination and satiety. High levels of vagal activity result in an increase in pain detection thresholds. Depressive symptoms were assessed using the Beck Depression Inventory (BDI). Positron Emission Tomography (PET) was used to identify higher cortical brain areas activated by vagal stimulation produced by proximal gastric distention in normal eating subjects. Double-blind treatment of severe bulimia nervosa subjects with ONDAN resulted in a rapid and significant decrease in binge-eating and vomiting compared to placebo controls. The decrease in abnormal eating episodes was accompanied by a return of normal satiety. Pain detection thresholds measured weekly over the course of the treatment protocol were found to dynamically fluctuate in association with bulimic episodes. Thresholds were the most elevated during periods of short-term abstinence from the behaviors, suggesting that not engaging in a binge/vomit episode is accompanied by an increase in vagal activity. ONDAN also resulted in abolition of the

Functions of the Renal Nerves.

ERIC Educational Resources Information Center

Koepke, John P.; DiBona, Gerald F.

1985-01-01

Discusses renal neuroanatomy, renal vasculature, renal tubules, renin secretion, renorenal reflexes, and hypertension as related to renal nerve functions. Indicates that high intensitites of renal nerve stimulation have produced alterations in several renal functions. (A chart with various stimulations and resultant renal functions and 10-item,…

Vagal Flexibility: A Physiological Predictor of Social Sensitivity

PubMed Central

Muhtadie, Luma; Akinola, Modupe; Koslov, Katrina; Mendes, Wendy Berry

2015-01-01

This research explores vagal flexibility— dynamic modulation of cardiac vagal control—as an individual-level physiological index of social sensitivity. In 4 studies, we test the hypothesis that individuals with greater cardiac vagal flexibility, operationalized as higher cardiac vagal tone at rest and greater cardiac vagal withdrawal (indexed by a decrease in respiratory sinus arrhythmia) during cognitive or attentional demand, perceive social-emotional information more accurately and show greater sensitivity to their social context. Study 1 sets the foundation for this investigation by establishing that vagal flexibility can be elicited consistently in the laboratory and reliably over time. Study 2 demonstrates that vagal flexibility has different associations with psychological characteristics than does vagal tone, and that these characteristics are primarily social in nature. Study 3 links individual differences in vagal flexibility with accurate detection of social and emotional cues depicted in still facial images. Study 4 demonstrates that individuals with greater vagal flexibility respond to dynamic social feedback in a more context-sensitive manner than do individuals with less vagal flexibility. Specifically, compared with their less flexible counterparts, individuals with greater vagal flexibility, when assigned to receive negative social feedback, report more shame, show more pronounced blood pressure responses, and display less sociable behavior, but when receiving positive social feedback display more sociable behavior. Taken together, these findings suggest that vagal flexibility is a useful individual difference physiological predictor of social sensitivity, which may have implications for clinical, developmental, and health psychologists. PMID:25545841

Reduced cardiac vagal activity in obese children and adolescents.

PubMed

Dangardt, Frida; Volkmann, Reinhard; Chen, Yun; Osika, Walter; Mårild, Staffan; Friberg, Peter

2011-03-01

  Obese children present with various cardiovascular risk factors affecting their future health. In adults, cardiac autonomic function is a major risk factor, predicting cardiovascular morbidity and mortality. We hypothesized that obese children and adolescents had a lower cardiac vagal activity than lean subjects. We measured cardiac spontaneous baroreflex sensitivity (BRS), reflecting the dynamic regulation of cardiac vagal function, in large groups of obese and lean young individuals.   Cardiac BRS, using the sequence approach, was assessed in 120 obese (59 girls), 43 overweight (23 girls) and 148 lean subjects (78 girls). Obese subjects showed a decreased BRS compared to both overweight and lean subjects [16±7 versus 21±9 (P<0·01) and 22±10 ms per mmHg (P<0·0001), respectively]. The differences remained after correcting for age, gender and pubertal status.   Children with obesity had low vagal activity at rest, and there was no gender difference. © 2010 The Authors. Clinical Physiology and Functional Imaging © 2010 Scandinavian Society of Clinical Physiology and Nuclear Medicine.

Monitoring of the posterior cricoarytenoid muscle represents another option for neural monitoring during thyroid surgery: Normative vagal and recurrent laryngeal nerve posterior cricoarytenoid muscle electromyographic data.

PubMed

Liddy, Whitney; Barber, Samuel R; Lin, Brian M; Kamani, Dipti; Kyriazidis, Natalia; Lawson, Bradley; Randolph, Gregory W

2018-01-01

Intraoperative neural monitoring (IONM) of laryngeal nerves using electromyography (EMG) is routinely performed using endotracheal tube surface electrodes adjacent to the vocalis muscles. Other laryngeal muscles such as the posterior cricoarytenoid muscle (PCA) are indirectly monitored. The PCA may be directly and reliably monitored through an electrode placed in the postcricoid region. Herein, we describe the method and normative data for IONM using PCA EMG. Retrospective review. Data were reviewed retrospectively for thyroid and parathyroid surgery patients with IONM of laryngeal nerves from January to August 2016. Recordings of vocalis and PCA EMG amplitudes and latencies with stimulation of laryngeal nerves were obtained using endotracheal (ET) tube-based and postcricoid surface electrodes. Data comprised EMG responses in vocalis and PCA recording channels with stimulation of the vagus, recurrent laryngeal nerve (RLN), and external branch of the superior laryngeal nerve from 20 subjects (11 left, 9 right), as well as PCA EMG threshold data with RLN stimulation from 17 subjects. Mean EMG amplitude was 725.69 ± 108.58 microvolts (µV) for the ipsilateral vocalis and 329.44 ± 34.12 µV for the PCA with vagal stimulation, and 1,059.75 ± 140.40 µV for the ipsilateral vocalis and 563.88 ± 116.08 µV for the PCA with RLN stimulation. There were no statistically significant differences in mean latency. For threshold cutoffs of the PCA with RLN stimulation, mean minimum and maximum threshold intensities were 0.37 milliamperes (mA) and 0.84 mA, respectively. This study shows robust and reliable PCA EMG waveforms with direct nerve stimulation. Further studies will evaluate feasibility and application of the PCA electrode as a complementary quantitative tool in IONM. 4. Laryngoscope, 128:283-289, 2018. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

Interganglionic segregation of distinct vagal afferent fibre phenotypes in guinea-pig airways.

PubMed Central

Ricco, M M; Kummer, W; Biglari, B; Myers, A C; Undem, B J

1996-01-01

1. The present study addressed the hypothesis that jugular and nodose vagal ganglia contain the somata of functionally and anatomically distinct airway afferent fibres. 2. Anatomical investigations were performed by injecting guinea-pig airways with the neuronal tracer Fast Blue. The animals were killed 7 days later, and the ganglia were removed and immunostained with antisera against substance P (SP) and neurofilament protein (NF). In the nodose ganglion, NF-immunoreactive neurones accounted for about 98% of the Fast Blue-labelled cells while in the jugular ganglion they accounted for approximately 48%. SP and NF immunoreactivity was never (n = 100) observed in the same cell suggesting that the antisera labelled distinct populations. 3. Electrophysiological investigations were performed using an in vitro guinea-pig tracheal and bronchial preparation with intact afferent vagal pathways, including nodose and jugular ganglia. Action potentials arriving from single airway afferent nerve endings were monitored extracellularly using a glass microelectrode positioned near neuronal cell bodies in either ganglion. 4. The nodose ganglion contained the somata of mainly fast-conducting tracheal A delta fibres whereas the jugular ganglion contained equal numbers of C fibre and A delta fibre tracheal afferent somata. The nodose A delta neurones adapted rapidly to mechanical stimulation, had relatively low mechanical thresholds, were not activated by capsaicin and adapted rapidly to a hyperosmotic stimulus. By contrast, jugular A delta and C fibres adapted slowly to mechanical stimulation, were often activated by capsaicin, had higher mechanical thresholds and displayed a slow adaptation to a hyperosmotic stimulus. 5. The anatomical, physiological and pharmacological data provide evidence to support the contention that the vagal ganglionic source of the fibre supplying the airways ultimately dictates its neurochemical and physiological phenotype. Images Figure 1 PMID:8910234

Vagus nerve is involved in the changes in body temperature induced by intragastric administration of 1,8-cineole via TRPM8 in mice.

PubMed

Urata, Tomomi; Mori, Noriyuki; Fukuwatari, Tsutomu

2017-05-22

Transient Receptor Potential Melastatin 8 (TRPM8) is a cold receptor activated by mild cold temperature (<28°C). TRPM8 expressed in cutaneous sensory nerves is involved in cold sensation and thermoregulation. TRPM8 mRNA is detected in various tissues, including the gastrointestinal mucosa, and in the vagal afferent nerve. The relationship between vagal afferent nerve-specific expression of TRPM8 and thermoregulation remains unclear. In this study, we aimed to investigate whether TRPM8 expression in the vagal afferent nerve is involved in autonomic thermoregulation. We found that intragastric administration of 1,8-cineole, a TRPM8 agonist, increased intrascapular brown adipose tissue and colonic temperatures, and M8-B-treatment (TRPM8 antagonist) inhibited these responses. Intravenous administration of 1,8-cineole also showed similar effects. In vagotomized mice, the responses induced by intragastric administration of 1,8-cineole were attenuated. These results suggest that TRPM8 expressed in tissues apart from cutaneous sensory nerves are involved in autonomic thermoregulation response. Copyright © 2017 Elsevier B.V. All rights reserved.

Experimental studies of gastric dysfunction in motion sickness: The effect of gastric and vestibular stimulation on the vagal and splanchnic gastric efferents

NASA Technical Reports Server (NTRS)

Niijima, A.; Jiang, Z. Y.; Daunton, Nancy G.; Fox, Robert A.

1991-01-01

The experiments were conducted in anaesthetized rats. In the first part of the experiments, the effect of CuSO4 on the afferent activity in the gastric branch of the vagus nerve was investigated. Gastric perfusion of CuSO4 solution (0.04 percent and 0.08 percent) provoked an increase in afferent activity. In the second part of the experiments, the reflex effects of gastric perfusion of CuSO4 solution, repetitive stimulation of the gastric vagus nerve, and caloric stimulation of the right vestibular apparatus (5-18 C water) on gastric autonomic outflow were investigated. The results of these experiments showed that these three different types of stimulation caused an inhibition in efferent activity of the gastric vagus nerve and a slight activation of the splanchnic gastric efferents. The summation of the effect of each stimulation was also observed. These results, therefore, provide evidence for a possible integrative inhibitory function of the vagal gastric center as well as an excitatory function of gastric sympathetic motoneurons in relation to motion sickness.

A novel surgical procedure of vagal nerve, lower esophageal sphincter, and pyloric sphincter-preserving nearly total gastrectomy reconstructed by single jejunal interposition, and postoperative quality of life.

PubMed

Tomita, Ryouichi

2005-01-01

For early gastric cancer total gastrectomy (TG) has so far been essentially unavoidable. We performed the nearly TG reconstructed by single jejunal interposition preservation of the vagal nerve, lower esophageal sphincter (LES) and pyloric sphincter (D1 or D2 lymph node dissection, curability A) as a function-preserving surgical technique (i.e. NTG) to improve postoperative quality of life (QOL). In this report, the application criteria and points of the technique are outlined. QOL in patients after NTG was also compared with those after TG. Sixteen subjects who underwent NTG (12 men and 4 women subjects at age 30 to 70 years, mean 55.6 years) were interviewed to inquire about abdominal symptoms and compared with 20 patients after conventional TG (excision with D2 lymph node, radical curability A) reconstructed by single jejunal interposition without preserving the vagal nerve, LES, and pyloric sphincter (i.e. TGI; 14 men and 6 women at age 26 to 70 years, mean 54.8 years). The former was named group A and the latter group B. Included were cases with early cancer localizing at the upper third and middle stomach, 2cm or further in distance from oral-side margin of the cancer to esophagogastric mucosal junction; and 3.5cm or further in distance from anal-side margin of the cancer to the pyloric sphincter. In excision with the lymph node, hepatic and celiac branches were preserved. To preserve LES, the abdominal esophagus was completely preserved. The pyloric antrum was also preserved at 1.5cm from the pyloric sphincter. The substitute stomach was created as a 30-cm-long single jejunal segment having orthodromic peristaltic movement. The operative procedure in group A significantly improved postoperative gastrointestinal symptoms such as appetite loss (p=0.0004), weight loss (p=0.0369), reflux esophagitis (RE) (p=0.0163), early dumping syndrome (p=0.0163), endoscopic RE (p=0.0311), and postgastrectomy cholecystolithiasis (p=0.0163) compared with group B. Oral intake

Vagal afferents contribute to exacerbated airway responses following ozone and allergen challenge

PubMed Central

Schelegle, Edward S.; Walby, William F.

2012-01-01

Brown-Norway rats (n = 113) sensitized and challenged with nDer f 1 allergen were used to examine the contribution of lung sensory nerves to ozone (O3) exacerbation of asthma. Prior to their third challenge rats inhaled 1.0 ppm O3 for 8 hours. There were three groups: 1) control; 2) vagus perineural capsaicin treatment (PCT) with or without hexamethonium; and 3) vagotomy. O3 inhalation resulted in a significant increase in lung resistance (RL) and an exaggerated response to subsequent allergen challenge. PCT abolished the O3-induced increase in RL and significantly reduced the increase in RL induced by a subsequent allergen challenge, while hexamethonium treatment reestablished bronchoconstriction induced by allergen challenge. Vagotomy resulted in a significant increase in the bronchoconstriction induced by O3 inhalation and subsequent challenge with allergen. In this model of O3 exacerbation of asthma, vagal C-fibers initiate reflex bronchoconstriction, vagal myelinated fibers initiate reflex bronchodilation, and mediators released within the airway initiate bronchoconstriction. PMID:22525484

Gut vagal afferents are necessary for the eating-suppressive effect of intraperitoneally administered ginsenoside Rb1 in rats.

PubMed

Shen, Ling; Wang, David Q-H; Lo, Chunmin C; Arnold, Myrtha; Tso, Patrick; Woods, Stephen C; Liu, Min

2015-12-01

Ginsenoside Rb1 (Rb1) reduces food intake in both lean and high-fat diet induced-obese rats; however, the sites and/or mediation of the eating-suppressive effect of Rb1 have not previously been identified. We hypothesized that intraperitoneally (ip) administered Rb1 exerts its anorectic action by enhancing sensitivity to satiation signals, such as cholecystokinin (CCK), and/or that it acts through vagal afferent nerves that relay the satiating signaling to the hindbrain. To test these hypotheses, we gave ip bolus doses of Rb1 (2.5-10.0mg/kg) and CCK-8 (0.125-4.0μg/kg) alone or in combination and assessed food intake in rats. Low doses of Rb1 (2.5mg/kg) or CCK-8 (0.125μg/kg) alone had no effect on food intake whereas higher doses did. When these subthreshold doses of Rb1 and CCK-8 were co-administered, the combination significantly reduced food intake relative to saline controls, and this effect was attenuated by lorglumide, a selective CCK1-receptor antagonist. Interestingly, lorglumide blocked food intake induced by an effective dose of CCK-8 alone, but not by Rb1 alone, suggesting that Rb1's anorectic effect is independent of the CCK1 receptor. To determine whether peripherally administered Rb1 suppresses feeding via abdominal vagal nerves, we evaluated the effect of ip Rb1 injection in subdiaphragmatic vagal deafferentation (SDA) and control rats. Rb1's effect on food intake was significantly attenuated in SDA rats, compared with that in SHAM controls. These data indicate that the vagal afferent system is the major pathway conveying peripherally administered Rb1's satiation signal. Copyright © 2015 Elsevier Inc. All rights reserved.

Acute ivabradine treatment reduces heart rate without increasing atrial fibrillation inducibility irrespective of underlying vagal activity in dogs.

PubMed

Uemura, Kazunori; Inagaki, Masashi; Zheng, Can; Kawada, Toru; Li, Meihua; Fukumitsu, Masafumi; Sugimachi, Masaru

2017-04-01

Ivabradine, a bradycardic agent, has been shown to stably reduce patient's heart rate (HR) in the setting of acute cardiac care. However, an association between atrial fibrillation (AF) risk and acute ivabradine treatment remains a controversial clinical issue, and has not been thoroughly investigated. Bradycardia and abnormal atrial refractoriness induced by ivabradine treatment may enhance vulnerability to AF induction, especially when vagal nerve is concurrently activated. We aimed to experimentally investigate the effects of acute ivabradine treatment with/without concurrent vagal activation on AF inducibility. In 16 anesthetized dogs, cervical vagal nerves were prepared for electrical stimulation (VS). AF induction rate (AFIR) was determined by atrial burst pacing. HR, atrial action potential duration (APD), atrial effective refractory period (ERP), and AFIR were obtained consecutively at baseline, during delivery of VS (VS alone), after intravenous injection of ivabradine 0.5 mg/kg (n = 8, ivabradine group) or saline (n = 8, saline group), and again during VS delivery (drug+VS). In the ivabradine group, ivabradine alone significantly lowered HR compared to baseline, while ivabradine+VS significantly lowered HR compared to VS alone. Contrary to expectations, there were no significant differences in trends of APD, temporal dispersion of APD, ERP, and AFIR between ivabradine and saline groups. Irrespective of whether ivabradine or saline was injected, VS significantly shortened APD and ERP, and increased AFIR. Interestingly, although bradycardia in response to ivabradine injection was more intense than that to VS alone, AFIR was significantly lower after ivabradine injection than during VS alone. We conclude that, despite its intense bradycardic effect, acute ivabradine treatment does not increase AF inducibility irrespective of underlying vagal activity. This study may constitute support for the safety of using ivabradine in the setting of acute cardiac

Evidence that antidromically stimulated vagal afferents activate inhibitory neurones innervating guinea-pig trachealis.

PubMed Central

Canning, B J; Undem, B J

1994-01-01

1. We recently described a capsaicin-sensitive vagal pathway mediating non-adrenergic, non-cholinergic (NANC) relaxations of an isolated, innervated rostral guinea-pig tracheal preparation. These afferent fibres are carried by the superior laryngeal nerves and relaxations elicited by their activation are insensitive to autonomic ganglion blockers such as hexamethonium. In the present study this vagal relaxant pathway was further characterized. 2. Relaxations of the trachealis elicited by electrical stimulation of capsaicin-sensitive vagal afferents were mimicked by bath application of capsaicin. Relaxations elicited by both methods were abolished when the tissue between the trachea and the adjacent oesophagus was disrupted. Indeed, separating the trachea from the oesophagus uncovered a contractile effect of capsaicin administration on the trachealis. 3. Capsaicin-induced, oesophagus-dependent relaxations of the trachealis were blocked by pretreatment with the fast sodium channel blocker tetrodotoxin (TTX). By contrast, capsaicin-induced contractions of the trachealis (obtained in the absence of the oesophagus) were unaffected by tetrodotoxin. 4. Substance P, neurokinin A (NKA) and neurokinin B (NKB) also elicited NANC relaxations of precontracted trachealis that were abolished by separating the trachea from the oesophagus or by TTX pretreatment. Like capsaicin, the tachykinins elicited only contractions of the trachealis following TTX pretreatment or separation of the trachea from the adjacent oesophagus. 5. Relaxations elicited by stimulation of the capsaicin-sensitive nerves were unaffected by a concentration of the tachykinin NK2 receptor-selective antagonist, SR 48968, that is selective for NK2 receptor blockade and were not mimicked by the NK2 receptor-selective agonist [beta-Ala8]-NKA(4-10). This suggests that NK2 receptors are not responsible for these relaxations. By contrast, the NK3 receptor-selective agonist, senktide analogue, and the NK1 receptor

MEAL PARAMETERS AND VAGAL GASTROINTESTINAL AFFERENTS IN MICE THAT EXPERIENCED EARLY POSTNATAL OVERNUTRITION

PubMed Central

Biddinger, Jessica E.; Fox, Edward A.

2010-01-01

Early postnatal overnutrition results in a predisposition to develop obesity due in part to hypothalamic and sympathetic dysfunction. Potential involvement of another major regulatory system component - the vagus nerve - has not been examined. Moreover, feeding disturbances have rarely been investigated prior to development of obesity when confounds due to obesity are minimized. To examine these issues, litters were culled on the day of birth to create small litters (SL; overnutrition), or normal-size litters (NL; normal nutrition). Body weight, fat pad weight, meal patterns, and vagal sensory duodenal innervation were compared between SL and NL adult mice prior to development of obesity. Meal patterns were studied 18 hour/day for 3 weeks using a balanced diet. Then vagal mechanoreceptors were labeled using anterograde transport of wheatgerm agglutinin-horseradish peroxidase injected into the nodose ganglion and their density and morphology were examined. Between postnatal day 1 and weaning, body weight of SL mice was greater than for NL mice. By young adulthood it was similar in both groups, whereas SL fat pad weight was greater in males, suggesting postnatal overnutrition produced a predisposition to obesity. SL mice exhibited increased food intake, decreased satiety ratio, and increased first meal rate (following mild food deprivation) compared to NL mice, suggesting postnatal overnutrition disrupted satiety. The density and structure of intestinal IGLEs appeared similar in SL and NL mice. Thus, although a vagal role cannot be excluded, our meal parameter and anatomical findings provided no evidence for significant postnatal overnutrition effects on vagal gastrointestinal afferents. PMID:20403369

Meal parameters and vagal gastrointestinal afferents in mice that experienced early postnatal overnutrition.

PubMed

Biddinger, Jessica E; Fox, Edward A

2010-08-04

Early postnatal overnutrition results in a predisposition to develop obesity due in part to hypothalamic and sympathetic dysfunction. Potential involvement of another major regulatory system component--the vagus nerve--has not been examined. Moreover, feeding disturbances have rarely been investigated prior to development of obesity when confounds due to obesity are minimized. To examine these issues, litters were culled on the day of birth to create small litters (SL; overnutrition), or normal size litters (NL; normal nutrition). Body weight, fat pad weight, meal patterns, and vagal sensory duodenal innervation were compared between SL and NL adult mice prior to development of obesity. Meal patterns were studied 18 h/day for 3 weeks using a balanced diet. Then vagal mechanoreceptors were labeled using anterograde transport of wheatgerm agglutinin-horseradish peroxidase injected into the nodose ganglion and their density and morphology were examined. Between postnatal day 1 and weaning, body weight of SL mice was greater than for NL mice. By young adulthood it was similar in both groups, whereas SL fat pad weight was greater in males, suggesting postnatal overnutrition produced a predisposition to obesity. SL mice exhibited increased food intake, decreased satiety ratio, and increased first meal rate (following mild food deprivation) compared to NL mice, suggesting postnatal overnutrition disrupted satiety. The density and structure of intestinal IGLEs appeared similar in SL and NL mice. Thus, although a vagal role cannot be excluded, our meal parameter and anatomical findings provided no evidence for significant postnatal overnutrition effects on vagal gastrointestinal afferents. Copyright 2010 Elsevier Inc. All rights reserved.

Prolactin-releasing peptide affects gastric motor function in rat by modulating synaptic transmission in the dorsal vagal complex.

PubMed

Grabauskas, Gintautas; Zhou, Shi-Yi; Das, Sudipto; Lu, Yuanxu; Owyang, Chung; Moises, Hylan C

2004-12-15

. Superfusion of brain slices with PrRP (100-300 nm) produced a small depolarization and increased spontaneous firing in 10 of 30 retrogradely labelled gastric-projecting DMV neurones. The excitatory effects were blocked by administration of TTX (2 mum) or specific glutamate receptor antagonists, indicating that they resulted from interactions of PrRP at a presynaptic site. Congruent with this, PrRP increased the amplitude of excitatory postsynaptic currents (EPSCs, 154 +/- 33%, 12 of 25 neurones) evoked by electrical stimulation in mNTS or comNTS. In addition, administration of PrRP decreased the paired-pulse ratio of EPSCs evoked by two identical stimuli delivered 100 ms apart (from 0.95 +/- 0.08 to 0.71 +/- 0.11, P < 0.05), whereas it did not affect the amplitude of inward currents evoked by exogenous application of L-glutamate to the slice. The frequency, but not amplitude of spontaneous EPSCs and action potential-independent miniature EPSCs was also increased by administration of PrRP, suggesting that the peptide was acting at least in part at receptors on presynaptic nerve terminals to enhance glutamatergic transmission. In recordings obtained from a separate group of slices, we did not observe any direct effects of PrRP on spontaneous discharge or postsynaptic excitability in either mNTS or comNTS neurones (n = 31). These data indicate that PrRP may act within the DVC to regulate gastric motor function by modulating the efficacy of conventional excitatory synaptic inputs from the NTS onto gastric-projecting vagal motor neurones.

Prolactin-releasing peptide affects gastric motor function in rat by modulating synaptic transmission in the dorsal vagal complex

PubMed Central

Grabauskas, Gintautas; Zhou, Shi-Yi; Das, Sudipto; Lu, Yuanxu; Owyang, Chung; Moises, Hylan C

2004-01-01

. Superfusion of brain slices with PrRP (100–300 nm) produced a small depolarization and increased spontaneous firing in 10 of 30 retrogradely labelled gastric-projecting DMV neurones. The excitatory effects were blocked by administration of TTX (2 μm) or specific glutamate receptor antagonists, indicating that they resulted from interactions of PrRP at a presynaptic site. Congruent with this, PrRP increased the amplitude of excitatory postsynaptic currents (EPSCs, 154 ± 33%, 12 of 25 neurones) evoked by electrical stimulation in mNTS or comNTS. In addition, administration of PrRP decreased the paired-pulse ratio of EPSCs evoked by two identical stimuli delivered 100 ms apart (from 0.95 ± 0.08 to 0.71 ± 0.11, P < 0.05), whereas it did not affect the amplitude of inward currents evoked by exogenous application of l-glutamate to the slice. The frequency, but not amplitude of spontaneous EPSCs and action potential-independent miniature EPSCs was also increased by administration of PrRP, suggesting that the peptide was acting at least in part at receptors on presynaptic nerve terminals to enhance glutamatergic transmission. In recordings obtained from a separate group of slices, we did not observe any direct effects of PrRP on spontaneous discharge or postsynaptic excitability in either mNTS or comNTS neurones (n = 31). These data indicate that PrRP may act within the DVC to regulate gastric motor function by modulating the efficacy of conventional excitatory synaptic inputs from the NTS onto gastric-projecting vagal motor neurones. PMID:15486017

Peripheral oxytocin activates vagal afferent neurons to suppress feeding in normal and leptin-resistant mice: a route for ameliorating hyperphagia and obesity.

PubMed

Iwasaki, Yusaku; Maejima, Yuko; Suyama, Shigetomo; Yoshida, Masashi; Arai, Takeshi; Katsurada, Kenichi; Kumari, Parmila; Nakabayashi, Hajime; Kakei, Masafumi; Yada, Toshihiko

2015-03-01

Oxytocin (Oxt), a neuropeptide produced in the hypothalamus, is implicated in regulation of feeding. Recent studies have shown that peripheral administration of Oxt suppresses feeding and, when infused subchronically, ameliorates hyperphagic obesity. However, the route through which peripheral Oxt informs the brain is obscure. This study aimed to explore whether vagal afferents mediate the sensing and anorexigenic effect of peripherally injected Oxt in mice. Intraperitoneal Oxt injection suppressed food intake and increased c-Fos expression in nucleus tractus solitarius to which vagal afferents project. The Oxt-induced feeding suppression and c-Fos expression in nucleus tractus solitarius were blunted in mice whose vagal afferent nerves were blocked by subdiaphragmatic vagotomy or capsaicin treatment. Oxt induced membrane depolarization and increases in cytosolic Ca(2+) concentration ([Ca(2+)]i) in single vagal afferent neurons. The Oxt-induced [Ca(2+)]i increases were markedly suppressed by Oxt receptor antagonist. These Oxt-responsive neurons also responded to cholecystokinin-8 and contained cocaine- and amphetamine-regulated transcript. In obese diabetic db/db mice, leptin failed to increase, but Oxt increased [Ca(2+)]i in vagal afferent neurons, and single or subchronic infusion of Oxt decreased food intake and body weight gain. These results demonstrate that peripheral Oxt injection suppresses food intake by activating vagal afferent neurons and thereby ameliorates obesity in leptin-resistant db/db mice. The peripheral Oxt-regulated vagal afferent neuron provides a novel target for treating hyperphagia and obesity. Copyright © 2015 the American Physiological Society.

Nerve Transfers to Restore Shoulder Function.

PubMed

Leechavengvongs, Somsak; Malungpaishorpe, Kanchai; Uerpairojkit, Chairoj; Ng, Chye Yew; Witoonchart, Kiat

2016-05-01

The restoration of shoulder function after brachial plexus injury represents a significant challenge facing the peripheral nerve surgeons. This is owing to a combination of the complex biomechanics of the shoulder girdle, the multitude of muscles and nerves that could be potentially injured, and a limited number of donor options. In general, nerve transfer is favored over tendon transfer, because the biomechanics of the musculotendinous units are not altered. This article summarizes the surgical techniques and clinical results of nerve transfers for restoration of shoulder function. Copyright © 2016 Elsevier Inc. All rights reserved.

Chronic cuffing of cervical vagus nerve inhibits efferent fiber integrity in rat model

NASA Astrophysics Data System (ADS)

Somann, Jesse P.; Albors, Gabriel O.; Neihouser, Kaitlyn V.; Lu, Kun-Han; Liu, Zhongming; Ward, Matthew P.; Durkes, Abigail; Robinson, J. Paul; Powley, Terry L.; Irazoqui, Pedro P.

2018-06-01

Objective. Numerous studies of vagal nerve stimulation (VNS) have been published showing it to be a potential treatment for chronic inflammation and other related diseases and disorders. Studies in recent years have shown that electrical stimulation of the vagal efferent fibers can artificially modulate cytokine levels and reduce systematic inflammation. Most VNS research in the treatment of inflammation have been acute studies on rodent subjects. Our study tested VNS on freely moving animals by stimulating and recording from the cervical vagus with nerve cuff electrodes over an extended period of time. Approach. We used methods of electrical stimulation, retrograde tracing (using Fluorogold) and post necropsy histological analysis of nerve tissue, flow cytometry to measure plasma cytokine levels, and MRI scanning of gastric emptying. This novel combination of methods allowed examination of physiological aspects of VNS previously unexplored. Main results. Through our study of 53 rat subjects, we found that chronically cuffing the left cervical vagus nerve suppressed efferent Fluorogold transport in 43 of 44 animals (36 showed complete suppression). Measured cytokine levels and gastric emptying rates concurrently showed nominal differences between chronically cuffed rats and those tested with similar acute methods. Meanwhile, results of electrophysiological and histological tests of the cuffed nerves revealed them to be otherwise healthy, consistent with previous literature. Significance. We hypothesize that due to these unforeseen and unexplored physiological consequences of the chronically cuffed vagus nerve in a rat, that inflammatory modulation and other vagal effects by VNS may become unreliable in chronic studies. Given our findings, we submit that it would benefit the VNS community to re-examine methods used in previous literature to verify the efficacy of the rat model for chronic VNS studies.

Miconazole enhances nerve regeneration and functional recovery after sciatic nerve crush injury.

PubMed

Lin, Tao; Qiu, Shuai; Yan, Liwei; Zhu, Shuang; Zheng, Canbin; Zhu, Qingtang; Liu, Xiaolin

2018-05-01

Improving axonal outgrowth and remyelination is crucial for peripheral nerve regeneration. Miconazole appears to enhance remyelination in the central nervous system. In this study we assess the effect of miconazole on axonal regeneration using a sciatic nerve crush injury model in rats. Fifty Sprague-Dawley rats were divided into control and miconazole groups. Nerve regeneration and myelination were determined using histological and electrophysiological assessment. Evaluation of sensory and motor recovery was performed using the pinprick assay and sciatic functional index. The Cell Counting Kit-8 assay and Western blotting were used to assess the proliferation and neurotrophic expression of RSC 96 Schwann cells. Miconazole promoted axonal regrowth, increased myelinated nerve fibers, improved sensory recovery and walking behavior, enhanced stimulated amplitude and nerve conduction velocity, and elevated proliferation and neurotrophic expression of RSC 96 Schwann cells. Miconazole was beneficial for nerve regeneration and functional recovery after peripheral nerve injury. Muscle Nerve 57: 821-828, 2018. © 2017 Wiley Periodicals, Inc.

Effect of mCOUP-TF1 deficiency on the glossopharyngeal and vagal sensory ganglia.

PubMed

Ichikawa, H; Lin, S-C; Tsai, S Y; Tsai, M-J; Sugimoto, T

2004-07-16

Immunohistochemistry for calcitonin gene-related peptide (CGRP), tyrosine hydroxylase and calbindin D-28k was performed on the glossopharyngeal and vagal ganglia in mCOUP-TFI knockout mice to know the effect of its deficiency on different types of primary sensory neurons. In wild type and heterozygous mice, the glossopharyngeal and vagal ganglia contained abundant CGRP-, tyrosine hydroxylase- and calbindin D-28k-immunoreactive (IR) neurons. In the ganglia of mCOUP-TFI knockout mice, a 38% decrease of CGRP-IR neurons was detected. However, the number of tyrosine hydroxylase- or calbindin D-28k-neurons was not altered by the mCOUP-TFI deficiency. In the tongue of knockout mice, the number of CGRP-IR nerve fibers decreased compared to wild-type and heterozygous mice. The development of CGRP-IR petrosal neurons, which supply innervation of the tongue, may depend on mCOUP-TFI.

Domestic Violence and Vagal Reactivity to Peer Provocation

PubMed Central

Katz, Lynn Fainsilber

2007-01-01

This paper examined whether individual differences in children’s vagal reactivity to peer provocation was related to domestic violence within the family. It also examined the question of whether conduct-problem children who show vagal augmentation to peer provocation come from families with high levels of domestic violence. During the peer provocation, children were expecting to interact with a difficult peer while vagal reactivity was assessed. Groups were divided into children who showed vagal augmentation and vagal suppression to the stressful peer interaction. Findings indicated that conduct-problem children who showed vagal augmentation to interpersonal challenge came from families with the highest levels of domestic violence. Vagal augmentation was also associated with a greater number of conduct-related problems for those children exposed to high levels of domestic violence. Discussion highlights the role of individual differences in physiological reactivity in understanding children’s behavior problems in relation to domestic violence. PMID:17118516

Factors Regulating Vagal Sensory Development: Potential Role in Obesities of Developmental Origin

PubMed Central

Fox, Edward A.; Murphy, Michelle C.

2008-01-01

Contributors to increased obesity in children may include perinatal under- or overnutrition. Humans and rodents raised under these conditions develop obesity, which like obesities of other etiologies has been associated with increased meal size. Since vagal sensory innervation of the gastrointestinal (GI) tract transmits satiation signals that regulate meal size, one mechanism through which abnormal perinatal nutrition could increase meal size is by altering vagal development, possibly by causing changes in the expression of factors that control it. Therefore, we have begun to characterize development of vagal innervation of the GI tract and the expression patterns and functions of the genes involved in this process. Important events in development of mouse vagal GI innervation occurred between midgestation and the second postnatal week, suggesting they could be vulnerable to effects of abnormal nutrition preor postnatally. One gene investigated was brain- derived neurotrophic factor (BDNF), which regulates survival of a subpopulation of vagal sensory neurons. BDNF was expressed in some developing stomach wall tissues innervated by vagal afferents. At birth, mice deficient in BDNF exhibited a 50% reduction of putative intraganglionic laminar ending mechanoreceptor precursors, and a 50% increase in axons that had exited fiber bundles. Additionally, BDNF was required for patterning of individual axons and fiber bundles in the antrum and differentiation of intramuscular array mechanoreceptors in the forestomach. It will be important to determine whether abnormal perinatal environments alter development of vagal sensory innervation of the GI tract, involving effects on expression of BDNF, or other factors regulating vagal development. PMID:18234244

Vagal Activity During Physiological Sexual Arousal in Women With and Without Sexual Dysfunction.

PubMed

Stanton, Amelia M; Pulverman, Carey S; Meston, Cindy M

2017-01-02

Recently, heart rate variability (HRV) level has been found to be a risk factor for female sexual dysfunction. Low HRV was a significant predictor of female sexual arousal dysfunction and overall sexual dysfunction. Building upon this finding, the present study examined whether differences in vagal activity between sexually functional and sexually dysfunctional women may be driving the association between low HRV and female sexual dysfunction. Specifically, respiratory sinus arrhythmia (RSA) was assessed before, during, and after physiological sexual arousal in 84 women, aged 18 to 47, to examine potential differences in vagal activity between sexually functional and sexually dysfunctional women. Significant differences in vagal activity between these two groups were observed (p =.02). These findings provide additional specificity to the recently established relationship between HRV and female sexual function while also proposing a mechanism to target during treatments for sexual dysfunction.

Gut vagal afferents differentially modulate innate anxiety and learned fear.

PubMed

Klarer, Melanie; Arnold, Myrtha; Günther, Lydia; Winter, Christine; Langhans, Wolfgang; Meyer, Urs

2014-05-21

Vagal afferents are an important neuronal component of the gut-brain axis allowing bottom-up information flow from the viscera to the CNS. In addition to its role in ingestive behavior, vagal afferent signaling has been implicated modulating mood and affect, including distinct forms of anxiety and fear. Here, we used a rat model of subdiaphragmatic vagal deafferentation (SDA), the most complete and selective vagal deafferentation method existing to date, to study the consequences of complete disconnection of abdominal vagal afferents on innate anxiety, conditioned fear, and neurochemical parameters in the limbic system. We found that compared with Sham controls, SDA rats consistently displayed reduced innate anxiety-like behavior in three procedures commonly used in preclinical rodent models of anxiety, namely the elevated plus maze test, open field test, and food neophobia test. On the other hand, SDA rats exhibited increased expression of auditory-cued fear conditioning, which specifically emerged as attenuated extinction of conditioned fear during the tone re-exposure test. The behavioral manifestations in SDA rats were associated with region-dependent changes in noradrenaline and GABA levels in key areas of the limbic system, but not with functional alterations in the hypothalamus-pituitary-adrenal grand stress. Our study demonstrates that innate anxiety and learned fear are both subjected to visceral modulation through abdominal vagal afferents, possibly via changing limbic neurotransmitter systems. These data add further weight to theories emphasizing an important role of afferent visceral signals in the regulation of emotional behavior. Copyright © 2014 the authors 0270-6474/14/347067-10$15.00/0.

Vagal afferents contribute to exacerbated airway responses following ozone and allergen challenge.

PubMed

Schelegle, Edward S; Walby, William F

2012-05-31

Brown-Norway rats (n=113) sensitized and challenged with nDer f 1 allergen were used to examine the contribution of lung sensory nerves to ozone (O(3)) exacerbation of asthma. Prior to their third challenge rats inhaled 1.0ppm O(3) for 8h. There were three groups: (1) control; (2) vagus perineural capsaicin treatment (PCT) with or without hexamethonium; and (3) vagotomy. O(3) inhalation resulted in a significant increase in lung resistance (R(L)) and an exaggerated response to subsequent allergen challenge. PCT abolished the O(3)-induced increase in R(L) and significantly reduced the increase in R(L) induced by a subsequent allergen challenge, while hexamethonium treatment reestablished bronchoconstriction induced by allergen challenge. Vagotomy resulted in a significant increase in the bronchoconstriction induced by O(3) inhalation and subsequent challenge with allergen. In this model of O(3) exacerbation of asthma, vagal C-fibers initiate reflex bronchoconstriction, vagal myelinated fibers initiate reflex bronchodilation, and mediators released within the airway initiate bronchoconstriction. Copyright © 2012 Elsevier B.V. All rights reserved.

Vagal nerve stimulation modulates the dendritic cell profile in posthemorrhagic shock mesenteric lymph.

PubMed

Morishita, Koji; Costantini, Todd W; Eliceiri, Brian; Bansal, Vishal; Coimbra, Raul

2014-03-01

Previous studies have established that posthemorrhagic shock mesenteric lymph (PHSML) contains proinflammatory mediators, while the cellular basis of PHSML is less well characterized in acute models of injury. CD103 dendritic cells (DCs) have been identified in the mesenteric lymph (ML) in models of chronic intestinal inflammation, suggesting an important role in the gut response to injury. We have previously demonstrated the ability of vagal nerve stimulation (VNS) to prevent gut barrier failure after trauma/hemorrhagic shock (T/HS); however, the ability of VNS to alter ML DCs is unknown. We hypothesized that the CD103 MHC-II DC population would change in PHSML and that VNS would prevent injury-induced changes in this population in PHSML. Male Sprague-Dawley rats were randomly assigned to trauma/sham shock or T/HS. T/HS was induced by midline laparotomy and 60 minutes of HS (blood pressure, 35 mm Hg), followed by fluid resuscitation. A separate cohort of animals underwent cervical VNS after the HS phase. Gut tissue was harvested at 2 hours after injury for histologic analysis. ML was collected during the pre-HS, HS, and post-HS phase. For flow cytometric analysis, ML cells were subjected to staining with CD103 and MHC-II antibodies, and this cell population was compared in the pre-HS and post-HS phase from the same animal. The CD4Foxp3 cell (T reg) population in the ML node (MLN) was also tested to determine effects of CD103 DC modulation in the ML. VNS reduced histologic gut injury and ML flow seen after injury. The CD103 MHC-II DC population in the PHSML was significantly decreased compared with pre-HS and was associated with decreased T reg expression in the MLN. VNS prevented the injury-induced decrease in the CD103 MHC-II+ DC population in the ML and restored the T reg population in the MLN. These findings suggest that VNS mediates the inflammatory responses in ML DCs and MLN T reg cells by affecting the set point of T/HS responsiveness.

Structural and functional cardiac cholinergic deficits in adult neurturin knockout mice.

PubMed

Mabe, Abigail M; Hoover, Donald B

2009-04-01

Previous work provided indirect evidence that the neurotrophic factor neurturin (NRTN) is required for normal cholinergic innervation of the heart. This study used nrtn knockout (KO) and wild-type (WT) mice to determine the effect of nrtn deletion on cardiac cholinergic innervation and function in the adult heart. Immunohistochemistry, confocal microscopy, and quantitative image analysis were used to directly evaluate intrinsic cardiac neuronal development. Atrial acetylcholine (ACh) levels were determined as an indirect index of cholinergic innervation. Cholinergic function was evaluated by measuring negative chronotropic responses to right vagal nerve stimulation in anaesthetized mice and responses of isolated atria to muscarinic agonists. KO hearts contained only 35% the normal number of cholinergic neurons, and the residual cholinergic neurons were 15% smaller than in WT. Cholinergic nerve density at the sinoatrial node was reduced by 87% in KOs, but noradrenergic nerve density was unaffected. Atrial ACh levels were substantially lower in KO mice (0.013 +/- 0.004 vs. 0.050 +/- 0.011 pmol/microg protein; P < 0.02) as expected from cholinergic neuron and nerve fibre deficits. Maximum bradycardia evoked by vagal stimulation was reduced in KO mice (38 +/- 6% vs. 69 +/- 3% decrease at 20 Hz; P < 0.001), and chronotropic responses took longer to develop and fade. In contrast to these deficits, isolated atria from KO mice had normal post-junctional sensitivity to carbachol and bethanechol. These findings demonstrate that NRTN is essential for normal cardiac cholinergic innervation and cholinergic control of heart rate. The presence of residual cardiac cholinergic neurons and vagal bradycardia in KO mice suggests that additional neurotrophic factors may influence this system.

An implantable nerve cooler for the exercising dog.

PubMed

Borgdorff, P; Versteeg, P G

1984-01-01

An implantable nerve cooler has been constructed to block cervical vago-sympathetic activity in the exercising dog reversibly. An insulated gilt brass container implanted around the nerve is perfused with cooled alcohol via silicone tubes. The flow of alcohol is controlled by an electromagnetic valve to keep nerve temperature at the required value. Nerve temperature is measured by a thermistor attached to the housing and in contact with the nerve. It is shown that, during cooling, temperature at this location differs less than 2 degrees C from nerve core temperature. Measurement of changes in heart rate revealed that complete vagal block in the conscious animal is obtained at a nerve temperature of 2 degrees C and can be achieved within 50 s. During steady-state cooling in the exercising animal nerve temperature varied less than 0.5 degree C. When the coolers after 2 weeks of implantation were removed they showed no oxydation and could be used again.

[Changes in the electrical activity of the rabbit proximal colon in vivo by stimulation of the vagus and splanchnic nerves].

PubMed

Julé, Y

1975-05-01

1. Using extracellular electrodes placed on the serosa, we recorded the modifications of the electrical activity of the colonic muslce fibers caused by the stimulation of vagal and splanchnic nerve fibers. 2. Vagal stimulation produces two types of junction potentials: excitatory junction potentials (EJPs) and inhibitory junction potentials (IJPs). The IJPs are elicited by stimulation of vagal fibers which innervate intramural non-adrenergic inhibitory neurons. 3. The conduction velocity of the nerve impulse along the vagal pre-ganglionic fibers is 1.01 m/sec for excitatory fibers and 0.5. m/sec for inhibitory fibers. 4. Splanchnic fiber stimulation causes EJP disappearance, blocking transmission between preganglionic fibers and intramural excitatory neurons, and a decrease in IJP amplitude that most likely indicates a previous hyperpolarization of the smooth muscle. 5. IJP persistence during splanchnic stimulation proves that sympathetic inhibition does not modify the transmission of the vagal influx onto the non-adrenergic inhibitory neurons of the intramural plexuses. 6. Through a comparative study of proximal and distal colonic innervation, we are able to show that there is a similar organization of both regions, that is a double inhibitory innervation: an adrenergic one of a sympathetic origin, and a non adrenergic one of a parasympathetic origin.

Resting Vagal Tone and Vagal Response to Stress: Associations with Anxiety, Aggression and Perceived Anxiety Control among Youth

PubMed Central

Scott, Brandon G.; Weems, Carl F.

2014-01-01

This study tested the associations of both resting vagal tone and vagal response to stress with anxiety control beliefs, anxiety, and aggression among 80 youth (aged 11-17 years). Measures included physiological assessments of emotion regulation along with youth self-report of anxiety control beliefs, anxiety, and aggression and caregiver reports of their child's anxiety and aggression. Resting vagal tone was positively related to anxiety control beliefs, but negatively associated with anxiety. Conversely, higher levels of anxiety and aggression were associated with increased vagal tone during a cognitive stress task. Findings suggest associations between physiological and self-report of emotion regulation (anxiety control beliefs) and that anxiety and aggression may have specific and non-specific relations with physiological indices of emotion regulation. PMID:24708059

TRP channel functions in the gastrointestinal tract.

PubMed

Yu, Xiaoyun; Yu, Mingran; Liu, Yingzhe; Yu, Shaoyong

2016-05-01

Transient receptor potential (TRP) channels are predominantly distributed in both somatic and visceral sensory nervous systems and play a crucial role in sensory transduction. As the largest visceral organ system, the gastrointestinal (GI) tract frequently accommodates external inputs, which stimulate sensory nerves to initiate and coordinate sensory and motor functions in order to digest and absorb nutrients. Meanwhile, the sensory nerves in the GI tract are also able to detect potential tissue damage by responding to noxious irritants. This nocifensive function is mediated through specific ion channels and receptors expressed in a subpopulation of spinal and vagal afferent nerve called nociceptor. In the last 18 years, our understanding of TRP channel expression and function in GI sensory nervous system has been continuously improved. In this review, we focus on the expressions and functions of TRPV1, TRPA1, and TRPM8 in primary extrinsic afferent nerves innervated in the esophagus, stomach, intestine, and colon and briefly discuss their potential roles in relevant GI disorders.

Police work stressors and cardiac vagal control.

PubMed

Andrew, Michael E; Violanti, John M; Gu, Ja K; Fekedulegn, Desta; Li, Shengqiao; Hartley, Tara A; Charles, Luenda E; Mnatsakanova, Anna; Miller, Diane B; Burchfiel, Cecil M

2017-09-10

This study examines relationships between the frequency and intensity of police work stressors and cardiac vagal control, estimated using the high frequency component of heart rate variability (HRV). This is a cross-sectional study of 360 officers from the Buffalo New York Police Department. Police stress was measured using the Spielberger police stress survey, which includes exposure indices created as the product of the self-evaluation of how stressful certain events were and the self-reported frequency with which they occurred. Vagal control was estimated using the high frequency component of resting HRV calculated in units of milliseconds squared and reported in natural log scale. Associations between police work stressors and vagal control were examined using linear regression for significance testing and analysis of covariance for descriptive purposes, stratified by gender, and adjusted for age and race/ethnicity. There were no significant associations between police work stressor exposure indices and vagal control among men. Among women, the inverse associations between the lack of support stressor exposure and vagal control were statistically significant in adjusted models for indices of exposure over the past year (lowest stressor quartile: M = 5.57, 95% CI 5.07 to 6.08, and highest stressor quartile: M = 5.02, 95% CI 4.54 to 5.51, test of association from continuous linear regression of vagal control on lack of support stressor β = -0.273, P = .04). This study supports an inverse association between lack of organizational support and vagal control among female but not male police officers. © 2017 Wiley Periodicals, Inc.

Vagal gustatory reflex circuits for intraoral food sorting behavior in the goldfish: cellular organization and neurotransmitters.

PubMed

Ikenaga, Takanori; Ogura, Tatsuya; Finger, Thomas E

2009-09-20

The sense of taste is crucial in an animal's determination as to what is edible and what is not. This gustatory function is especially important in goldfish, who utilize a sophisticated oropharyngeal sorting mechanism to separate food from substrate material. The computational aspects of this detection are carried out by the medullary vagal lobe, which is a large, laminated structure combining elements of both the gustatory nucleus of the solitary tract and the nucleus ambiguus. The sensory layers of the vagal lobe are coupled to the motor layers via a simple reflex arc. Details of this reflex circuit were investigated with histology and calcium imaging. Biocytin injections into the motor layer labeled vagal reflex interneurons that have radially directed dendrites ramifying within the layers of primary afferent terminals. Axons of reflex interneurons extend radially inward to terminate onto both vagal motoneurons and small, GABAergic interneurons in the motor layer. Functional imaging shows increases in intracellular Ca++ of vagal motoneurons following electrical stimulation in the sensory layer. These responses were suppressed under Ca(++)-free conditions and by interruption of the axons bridging between the sensory and motor layers. Pharmacological experiments showed that glutamate acting via (+/-)-alpha-amino-3-hydroxy- 5-ethylisoxazole-4-propioinc acid (AMPA)/kainate and N-methyl-D-aspartic acid (NMDA) receptors mediate neurotransmission between reflex interneurons and vagal motoneurons. Thus, the vagal gustatory portion of the viscerosensory complex is linked to branchiomotor neurons of the pharynx via a glutamatergic interneuronal system.

Vagal gustatory reflex circuits for intraoral food sorting behavior in the goldfish Cellular organization and neurotransmitters

PubMed Central

Ikenaga, Takanori; Ogura, Tatsuya; Finger, Thomas E.

2009-01-01

The sense of taste is crucial in an animal’s determination as to what is edible and what is not. This gustatory function is especially important in goldfish who utilize a sophisticated oropharyngeal sorting mechanism to separate food from substrate material. The computational aspects of this detection are carried out by the medullary vagal lobe which is a large, laminated structure combining elements of both the gustatory nucleus of the solitary tract and the nucleus ambiguus. The sensory layers of the vagal lobe are coupled to the motor layers via a simple reflex arc. Details of this reflex circuit were investigated with histology and calcium imaging. Biocytin injections into the motor layer labeled vagal reflex interneurons which have radially-directed dendrites ramifying within the layers of primary afferent terminals. Axons of reflex interneurons extend radially inward to terminate onto both vagal motoneurons and small, GABAergic interneurons in the motor layer. Functional imaging shows increases in intracellular Ca++ of vagal motoneurons following electrical stimulation in the sensory layer. These responses were suppressed under Ca++-free conditions and by interruption of the axons bridging between the sensory and motor layers. Pharmacological experiments showed that glutamate acting via (±)-α-amino-3-hydroxy-5-ethylisoxazole-4-propioinc acid (AMPA)/kainate and N-methyl-D-aspartic acid (NMDA) receptors mediates neurotransmission between reflex interneurons and vagal motoneurons. Thus the vagal gustatory portion of the viscerosensory complex is linked to branchiomotor neurons of the pharynx via a glutamatergic interneuronal system. PMID:19598285

Moderate Baseline Vagal Tone Predicts Greater Prosociality in Children

PubMed Central

Miller, Jonas G.; Kahle, Sarah; Hastings, Paul D.

2016-01-01

Vagal tone is widely believed to be an important physiological aspect of emotion regulation and associated positive behaviors. However, there is inconsistent evidence for relations between children’s baseline vagal tone and their helpful or prosocial responses to others (Hastings & Miller, 2014). Recent work in adults suggests a quadratic association (inverted U-shape curve) between baseline vagal tone and prosociality (Kogan et al., 2014). The present research examined whether this nonlinear association was evident in children. We found consistent evidence for a quadratic relation between vagal tone and prosociality across 3 samples of children using 6 different measures. Compared to low and high vagal tone, moderate vagal tone in early childhood concurrently predicted greater self-reported prosociality (Study 1), observed empathic concern in response to the distress of others and greater generosity toward less fortunate peers (Study 2), and longitudinally predicted greater self-, mother-, and teacher-reported prosociality 5.5 years later in middle childhood (Study 3). Taken together, our findings suggest that moderate vagal tone at rest represents a physiological preparedness or tendency to engage in different forms of prosociality across different contexts. Early moderate vagal tone may reflect an optimal balance of regulation and arousal that helps prepare children to sympathize, comfort, and share with others. PMID:27819463

Extracellular pH monitoring for use in closed-loop vagus nerve stimulation

NASA Astrophysics Data System (ADS)

Cork, Simon C.; Eftekhar, Amir; Mirza, Khalid B.; Zuliani, Claudio; Nikolic, Konstantin; Gardiner, James V.; Bloom, Stephen R.; Toumazou, Christofer

2018-02-01

Objective. Vagal nerve stimulation (VNS) has shown potential benefits for obesity treatment; however, current devices lack physiological feedback, which limit their efficacy. Changes in extracellular pH (pHe) have shown to be correlated with neural activity, but have traditionally been measured with glass microelectrodes, which limit their in vivo applicability. Approach. Iridium oxide has previously been shown to be sensitive to fluctuations in pH and is biocompatible. Iridium oxide microelectrodes were inserted into the subdiaphragmatic vagus nerve of anaesthetised rats. Introduction of the gut hormone cholecystokinin (CCK) or distension of the stomach was used to elicit vagal nerve activity. Main results. Iridium oxide microelectrodes have sufficient pH sensitivity to readily detect changes in pHe associated with both CCK and gastric distension. Furthermore, a custom-made Matlab script was able to use these changes in pHe to automatically trigger an implanted VNS device. Significance. This is the first study to show pHe changes in peripheral nerves in vivo. In addition, the demonstration that iridium oxide microelectrodes are sufficiently pH sensitive as to measure changes in pHe associated with physiological stimuli means they have the potential to be integrated into closed-loop neurostimulating devices.

Vagal Sensory Innervation of the Gastric Sling Muscle and Antral Wall: Implications for GERD?

PubMed Central

Powley, Terry L.; Gilbert, Jared M.; Baronowsky, Elizabeth A.; Billingsley, Cherie N.; Martin, Felecia N.; Phillips, Robert J.

2012-01-01

Background The gastric sling muscle has not been investigated for possible sensory innervation, in spite of the key roles the structure plays in lower esophageal sphincter (LES) function and gastric physiology. Thus, the present experiment used tracing techniques to label vagal afferents and survey their projections in the lesser curvature. Methods Sprague Dawley rats received injections of dextran biotin into the nodose ganglia. Fourteen days post-injection, animals were euthanized and their stomachs were processed to visualize the vagal afferent innervation. In different cases, neurons, muscle cells, or interstitial cells of Cajal were counterstained. Key Results The sling muscle is innervated throughout its length by vagal afferent intramuscular arrays (IMAs) associated with interstitial cells of Cajal. In addition, the distal antral attachment site of the sling muscle is innervated by a novel vagal afferent terminal specialization, an antral web ending. The muscle wall of the distal antrum is also innervated by conventional IMAs and intraganglionic laminar endings (IGLEs), the two types of mechanoreceptors found throughout stomach smooth muscle. Conclusions & Inferences The innervation of sling muscle by IMAs, putative stretch receptors, suggests that sling sensory feedback may generate vago-vagal or other reflexes with vagal afferent limbs. The restricted distribution of afferent web endings near the antral attachments of sling fibers suggests the possibility of specialized mechanoreceptor functions linking antral and pyloric activity to the operation of the LES. Dysfunctional sling afferents could generate LES motor disturbances, or normative compensatory sensory feedback from the muscle could compromise therapies targeting only effectors. PMID:22925069

The electrophysiology of thyroid surgery: electrophysiologic and muscular responses with stimulation of the vagus nerve, recurrent laryngeal nerve, and external branch of the superior laryngeal nerve.

PubMed

Liddy, Whitney; Barber, Samuel R; Cinquepalmi, Matteo; Lin, Brian M; Patricio, Stephanie; Kyriazidis, Natalia; Bellotti, Carlo; Kamani, Dipti; Mahamad, Sadhana; Dralle, Henning; Schneider, Rick; Dionigi, Gianlorenzo; Barczynski, Marcin; Wu, Che-Wei; Chiang, Feng Yu; Randolph, Gregory

2017-03-01

Correlation of physiologically important electromyographic (EMG) waveforms with demonstrable muscle activation is important for the reliable interpretation of evoked waveforms during intraoperative neural monitoring (IONM) of the vagus nerve, recurrent laryngeal nerve (RLN), and external branch of the superior laryngeal nerve (EBSLN) in thyroid surgery. Retrospective chart review. Data were reviewed retrospectively for thyroid surgery patients with laryngeal nerve IONM from January to December, 2015. EMG responses to monopolar stimulation of the vagus/RLN and EBSLN were recorded in bilateral vocalis, cricothyroid (CTM), and strap muscles using endotracheal tube-based surface and intramuscular hook electrodes, respectively. Target muscles for vagal/RLN and EBSLN stimulation were the ipsilateral vocalis and CTM, respectively. All other recording channels were nontarget muscles. Fifty surgical sides were identified in 37 subjects. All target muscle mean amplitudes were significantly higher than in nontarget muscles. With vagal/RLN stimulation, target ipsilateral vocalis mean amplitude was 1,095.7 μV (mean difference range = -814.1 to -1,078 μV, P < .0001). For EBSLN stimulation, target ipsilateral CTM mean amplitude was 6,379.3 μV (mean difference range = -6,222.6 to -6,362.3 μV, P < .0001). Target muscle large-amplitude EMG responses correlated with meaningful visual or palpable muscular responses, whereas nontarget EMG responses showed no meaningful muscle activation. Target and nontarget laryngeal muscles are differentiated based on divergence of EMG response directly correlating with presence or absence of visual and palpable muscle activation. Low-amplitude EMG waveforms in nontarget muscles with neural stimulation can be explained by the concept of far-field artifactual waveforms and do not correspond to a true muscular response. The surgeon should be aware of these nonphysiologic waveforms when interpreting and applying IONM during thyroid surgery. 4

Psychoactive bacteria Lactobacillus rhamnosus (JB-1) elicits rapid frequency facilitation in vagal afferents.

PubMed

Perez-Burgos, Azucena; Wang, Bingxian; Mao, Yu-Kang; Mistry, Bhavik; McVey Neufeld, Karen-Anne; Bienenstock, John; Kunze, Wolfgang

2013-01-15

Mounting evidence supports the influence of the gut microbiome on the local enteric nervous system and its effects on brain chemistry and relevant behavior. Vagal afferents are involved in some of these effects. We previously showed that ingestion of the probiotic bacterium Lactobacillus rhamnosus (JB-1) caused extensive neurochemical changes in the brain and behavior that were abrogated by prior vagotomy. Because information can be transmitted to the brain via primary afferents encoded as neuronal spike trains, our goal was to record those induced by JB-1 in vagal afferents in the mesenteric nerve bundle and thus determine the nature of the signals sent to the brain. Male Swiss Webster mice jejunal segments were cannulated ex vivo, and serosal and luminal compartments were perfused separately. Bacteria were added intraluminally. We found no evidence for translocation of labeled bacteria across the epithelium during the experiment. We recorded extracellular multi- and single-unit neuronal activity with glass suction pipettes. Within minutes of application, JB-1 increased the constitutive single- and multiunit firing rate of the mesenteric nerve bundle, but Lactobacillus salivarius (a negative control) or media alone were ineffective. JB-1 significantly augmented multiunit discharge responses to an intraluminal distension pressure of 31 hPa. Prior subdiaphragmatic vagotomy abolished all of the JB-1-evoked effects. This detailed exploration of the neuronal spike firing that encodes behavioral signaling to the brain may be useful to identify effective psychoactive bacteria and thereby offer an alternative new perspective in the field of psychiatry and comorbid conditions.

Renal dopamine containing nerves. What is their functional significance?

PubMed

DiBona, G F

1990-06-01

Biochemical and morphological studies indicate that there are nerves within the kidney that contain dopamine and that various structures within the kidney contain dopamine receptors. However, the functional significance of these renal dopamine containing nerves in relation to renal dopamine receptors is unknown. The functional significance could be defined by demonstrating that an alteration in one or more renal functions occurring in response to reflex or electrical activation of efferent renal nerves is dependent on release of dopamine as the neurotransmitter from the renal nerve terminals acting on renal dopamine receptors. Thus, the hypothesis becomes: reflex or electrical activation of efferent renal nerves causes alterations in renal function (eg, renal blood flow, water and solute handling) that are inhibited by specific and selective dopamine receptor antagonists. As reviewed herein, the published experimental data do not support the hypothesis. Therefore, the view that alterations in one or more renal functions occurring in response to reflex or electrical activation of efferent renal nerves are dependent on release of dopamine as the neurotransmitter from the renal nerve terminals acting on renal dopamine receptors remains unproven.

Effects of vagal deafferentation on oesophageal motility and transit in the sheep.

PubMed Central

Falempin, M; Madhloum, A; Rousseau, J P

1986-01-01

Effects of vagal deafferentation on oesophageal motility and transit were studied in conscious sheep by recording the electromyographic activity of different parts of oesophagus during swallowing of saliva, or balloons inflated with 20 ml of air. Surgical isolation and subsequent sectioning of the nodose ganglion, leaving the bundles of motor fibres intact, can be performed in sheep. Division of both ganglia led to immediate death of sheep. However, vagal deafferentation of the thoracic oesophagus could be achieved by sectioning the thoracic vagus nerve in association with sectioning the contralateral nodose ganglion. The sectioning of one vagus nerve did not affect primary oesophageal peristalsis during swallowing of saliva or of a bolus. Balloons inflated in the pharyngeal cavity and left free to move caudally, failed to pass into the stomach within the normal time of 2-2.3 s in only 4-16% of the tests. In these cases, they were always stopped in the thoracic oesophagus. Following total deafferentation of the thoracic oesophagus, balloons were prevented from being propelled into the stomach in each test. They were stopped for several minutes at the beginning of the deafferented part of the oesophagus. Electromyographic activity recorded from the deafferented part was reduced during swallowing of balloons or saliva. Deafferentation was confirmed by the failure of the presumed deafferented segment of oesophagus to respond to distension. These experiments provide direct evidence that the vagus carries information from the oesophagus which influences the central pattern generator during swallowing of a bolus or saliva. In sheep, this feed-back is essential for the effective swallowing of a bolus although not for saliva. PMID:3723412

Dopamine Mediates the Vagal Modulation of the Immune System by Electroacupuncture

PubMed Central

Torres-Rosas, Rafael; Yehia, Ghassan; Peña, Geber; Mishra, Priya; del Rocio Thompson-Bonilla, Maria; Moreno-Eutimio, Mario Adán; Arriaga-Pizano, Lourdes Andrea; Isibasi, Armando; Ulloa, Luis

2014-01-01

Previous anti-inflammatory strategies against sepsis, a leading cause of death in hospitals, had limited efficacy in clinical trials, in part because they targeted single cytokines and the experimental models failed to mimic clinical settings1-3. Neuronal networks represent physiological mechanisms selected by evolution to control inflammation that can be exploited for the treatment of inflammatory and infectious disorders3. Here, we report that sciatic nerve activation with electroacupuncture controls systemic inflammation and rescues mice from polymicrobial peritonitis. Electroacupuncture at the sciatic nerve controls systemic inflammation by inducing a vagal activation of DOPA decarboxylase leading to the production of dopamine in the adrenal medulla. Experimental models with adrenolectomized animals mimic clinical adrenal insufficiency4, increase the susceptibility to sepsis, and prevent the anti-inflammatory potential of electroacupuncture. Dopamine inhibits cytokine production via dopaminergic type-1 receptors. Dopaminergic D1-agonists suppress systemic inflammation and rescue mice from polymicrobial peritonitis in animals with adrenal insufficiency. Our results suggest a novel anti-inflammatory mechanism mediated by the sciatic and the vagus nerves modulating the production of catecholamines in the adrenal glands. From a pharmacological perspective, selective dopaminergic agonists mimic the anti-inflammatory potential of electroacupuncture and can provide therapeutic advantages to control inflammation in infectious and inflammatory disorders. PMID:24562381

Physiology and Functioning: Parents' Vagal Tone, Emotion Socialization, and Children's Emotion Knowledge

ERIC Educational Resources Information Center

Perlman, Susan B.; Camras, Linda A.; Pelphrey, Kevin A.

2008-01-01

This study examined relationships among parents' physiological regulation, their emotion socialization behaviors, and their children's emotion knowledge. Parents' resting cardiac vagal tone was measured, and parents provided information regarding their socialization behaviors and family emotional expressiveness. Their 4- or 5-year-old children (N…

Hippocampal-Brainstem Connectivity Associated with Vagal Modulation after an Intense Exercise Intervention in Healthy Men

PubMed Central

Bär, Karl-Jürgen; Herbsleb, Marco; Schumann, Andy; de la Cruz, Feliberto; Gabriel, Holger W.; Wagner, Gerd

2016-01-01

Regular physical exercise leads to increased vagal modulation of the cardiovascular system. A combination of peripheral and central processes has been proposed to underlie this adaptation. However, specific changes in the central autonomic network have not been described in human in more detail. We hypothesized that the anterior hippocampus known to be influenced by regular physical activity might be involved in the development of increased vagal modulation after a 6 weeks high intensity intervention in young healthy men (exercise group: n = 17, control group: n = 17). In addition to the determination of physical capacity before and after the intervention, we used resting state functional magnetic resonance imaging and simultaneous heart rate variability assessment. We detected a significant increase of the power output at the anaerobic threshold of 11.4% (p < 0.001), the maximum power output Pmax of 11.2% (p < 0.001), and VO2max adjusted for body weight of 4.7% (p < 0.001) in the exercise group (EG). Comparing baseline (T0) and post-exercise (T1) values of parasympathetic modulation of the exercise group, we observed a trend for a decrease in heart rate (p < 0.06) and a significant increase of vagal modulation as indicated by RMSSD (p < 0.026) during resting state. In the whole brain analysis, we found that the connectivity pattern of the right anterior hippocampus (aHC) was specifically altered to the ventromedial anterior cortex, the dorsal striatum and to the dorsal vagal complex (DVC) in the brainstem. Moreover, we observed a highly significant negative correlation between increased RMSSD after exercise and decreased functional connectivity from the right aHC to DVC (r = −0.69, p = 0.003). This indicates that increased vagal modulation was associated with functional connectivity between aHC and the DVC. In conclusion, our findings suggest that exercise associated changes in anterior hippocampal function might be involved in increased vagal modulation. PMID

Neurotrophin expression and laryngeal muscle pathophysiology following recurrent laryngeal nerve transection

PubMed Central

WANG, BAOXIN; YUAN, JUNJIE; XU, JIAFENG; XIE, JIN; WANG, GUOLIANG; DONG, PIN

2016-01-01

Laryngeal palsy often occurs as a result of recurrent laryngeal or vagal nerve injury during oncological surgery of the head and neck, affecting quality of life and increasing economic burden. Reinnervation following recurrent laryngeal nerve (RLN) injury is difficult despite development of techniques, such as neural anastomosis, nerve grafting and creation of a laryngeal muscle pedicle. In the present study, due to the limited availability of human nerve tissue for research, a rat model was used to investigate neurotrophin expression and laryngeal muscle pathophysiology in RLN injury. Twenty-five male Sprague-Dawley rats underwent right RLN transection with the excision of a 5-mm segment. Vocal fold movements, vocalization, histology and immunostaining were evaluated at different time-points (3, 6, 10 and 16 weeks). Although vocalization was restored, movement of the vocal fold failed to return to normal levels following RLN injury. The expression of brain-derived neurotrophic factor and glial cell line-derived neurotrophic factor differed in the thyroarytenoid (TA) and posterior cricoarytenoid muscles. The number of axons did not increase to baseline levels over time. Furthermore, normal muscle function was unlikely with spontaneous reinnervation. During regeneration following RLN injury, differences in the expression levels of neurotrophic factors may have resulted in preferential reinnervation of the TA muscles. Data from the present study indicated that neurotrophic factors may be applied for restoring the function of the laryngeal nerve following recurrent injury. PMID:26677138

Neurotrophin expression and laryngeal muscle pathophysiology following recurrent laryngeal nerve transection.

PubMed

Wang, Baoxin; Yuan, Junjie; Xu, Jiafeng; Xie, Jin; Wang, Guoliang; Dong, Pin

2016-02-01

Laryngeal palsy often occurs as a result of recurrent laryngeal or vagal nerve injury during oncological surgery of the head and neck, affecting quality of life and increasing economic burden. Reinnervation following recurrent laryngeal nerve (RLN) injury is difficult despite development of techniques, such as neural anastomosis, nerve grafting and creation of a laryngeal muscle pedicle. In the present study, due to the limited availability of human nerve tissue for research, a rat model was used to investigate neurotrophin expression and laryngeal muscle pathophysiology in RLN injury. Twenty-five male Sprague-Dawley rats underwent right RLN transection with the excision of a 5-mm segment. Vocal fold movements, vocalization, histology and immunostaining were evaluated at different time-points (3, 6, 10 and 16 weeks). Although vocalization was restored, movement of the vocal fold failed to return to normal levels following RLN injury. The expression of brain‑derived neurotrophic factor and glial cell line-derived neurotrophic factor differed in the thyroarytenoid (TA) and posterior cricoarytenoid muscles. The number of axons did not increase to baseline levels over time. Furthermore, normal muscle function was unlikely with spontaneous reinnervation. During regeneration following RLN injury, differences in the expression levels of neurotrophic factors may have resulted in preferential reinnervation of the TA muscles. Data from the present study indicated that neurotrophic factors may be applied for restoring the function of the laryngeal nerve following recurrent injury.

Respiratory modulation of human autonomic function: long-term neuroplasticity in space.

PubMed

Eckberg, Dwain L; Diedrich, André; Cooke, William H; Biaggioni, Italo; Buckey, Jay C; Pawelczyk, James A; Ertl, Andrew C; Cox, James F; Kuusela, Tom A; Tahvanainen, Kari U O; Mano, Tadaaki; Iwase, Satoshi; Baisch, Friedhelm J; Levine, Benjamin D; Adams-Huet, Beverley; Robertson, David; Blomqvist, C Gunnar

2016-10-01

We studied healthy astronauts before, during and after the Neurolab Space Shuttle mission with controlled breathing and apnoea, to identify autonomic changes that might contribute to postflight orthostatic intolerance. Measurements included the electrocardiogram, finger photoplethysmographic arterial pressure, respiratory carbon dioxide levels, tidal volume and peroneal nerve muscle sympathetic activity. Arterial pressure fell and then rose in space, and drifted back to preflight levels after return to Earth. Vagal metrics changed in opposite directions: vagal baroreflex gain and two indices of vagal fluctuations rose and then fell in space, and descended to preflight levels upon return to Earth. Sympathetic burst frequencies (but not areas) were greater than preflight in space and on landing day, and astronauts' abilities to modulate both burst areas and frequencies during apnoea were sharply diminished. Spaceflight triggers long-term neuroplastic changes reflected by reciptocal sympathetic and vagal motoneurone responsiveness to breathing changes. We studied six healthy astronauts five times, on Earth, in space on the first and 12th or 13th day of the 16 day Neurolab Space Shuttle mission, on landing day, and 5-6 days later. Astronauts followed a fixed protocol comprising controlled and random frequency breathing and apnoea, conceived to perturb their autonomic function and identify changes, if any, provoked by microgravity exposure. We recorded the electrocardiogram, finger photoplethysmographic arterial pressure, tidal carbon dioxide concentrations and volumes, and peroneal nerve muscle sympathetic activity on Earth (in the supine position) and in space. (Sympathetic nerve recordings were made during three sessions: preflight, late mission and landing day.) Arterial pressure changed systematically from preflight levels: pressure fell during early microgravity exposure, rose as microgravity exposure continued, and drifted back to preflight levels after return

Respiratory modulation of human autonomic function: long‐term neuroplasticity in space

PubMed Central

Diedrich, André; Cooke, William H.; Biaggioni, Italo; Buckey, Jay C.; Pawelczyk, James A.; Ertl, Andrew C.; Cox, James F.; Kuusela, Tom A.; Tahvanainen, Kari U.O.; Mano, Tadaaki; Iwase, Satoshi; Baisch, Friedhelm J.; Levine, Benjamin D.; Adams‐Huet, Beverley; Robertson, David; Blomqvist, C. Gunnar

2016-01-01

Key points We studied healthy astronauts before, during and after the Neurolab Space Shuttle mission with controlled breathing and apnoea, to identify autonomic changes that might contribute to postflight orthostatic intolerance.Measurements included the electrocardiogram, finger photoplethysmographic arterial pressure, respiratory carbon dioxide levels, tidal volume and peroneal nerve muscle sympathetic activity.Arterial pressure fell and then rose in space, and drifted back to preflight levels after return to Earth.Vagal metrics changed in opposite directions: vagal baroreflex gain and two indices of vagal fluctuations rose and then fell in space, and descended to preflight levels upon return to Earth.Sympathetic burst frequencies (but not areas) were greater than preflight in space and on landing day, and astronauts’ abilities to modulate both burst areas and frequencies during apnoea were sharply diminished.Spaceflight triggers long‐term neuroplastic changes reflected by reciptocal sympathetic and vagal motoneurone responsiveness to breathing changes. Abstract We studied six healthy astronauts five times, on Earth, in space on the first and 12th or 13th day of the 16 day Neurolab Space Shuttle mission, on landing day, and 5–6 days later. Astronauts followed a fixed protocol comprising controlled and random frequency breathing and apnoea, conceived to perturb their autonomic function and identify changes, if any, provoked by microgravity exposure. We recorded the electrocardiogram, finger photoplethysmographic arterial pressure, tidal carbon dioxide concentrations and volumes, and peroneal nerve muscle sympathetic activity on Earth (in the supine position) and in space. (Sympathetic nerve recordings were made during three sessions: preflight, late mission and landing day.) Arterial pressure changed systematically from preflight levels: pressure fell during early microgravity exposure, rose as microgravity exposure continued, and drifted back to preflight

Evaluation of phrenic nerve and diaphragm function with peripheral nerve stimulation and M-mode ultrasonography in potential pediatric phrenic nerve or diaphragm pacing candidates.

PubMed

Skalsky, Andrew J; Lesser, Daniel J; McDonald, Craig M

2015-02-01

Assessing phrenic nerve function in the setting of diaphragmatic paralysis in diaphragm pacing candidates can be challenging. Traditional imaging modalities and electrodiagnostic evaluations are technically difficult. Either modality alone is not a direct measure of the function of the phrenic nerve and diaphragm unit. In this article, the authors present their method for evaluating phrenic nerve function and the resulting diaphragm function. Stimulating the phrenic nerve with transcutaneous stimulation and directly observing the resulting movement of the hemidiaphragm with M-mode ultrasonography provides quantitative data for predicting the success of advancing technologies such as phrenic nerve pacing and diaphragm pacing. Copyright © 2015 Elsevier Inc. All rights reserved.

Importance of vagal input in maintaining gastric tone in the dog.

PubMed Central

Azpiroz, F; Malagelada, J R

1987-01-01

1. Using a gastric barostat to quantify variations in gastric tone, we had previously demonstrated that food ingestion or intestinal nutrient perfusion induces gastric relaxation. These data suggested a basal tonic contraction of the stomach during fasting. 2. To determine the role of vagal input in maintaining fasting gastric tone, we prepared two chronic canine models, either isolating both cervical vagal trunks in a cutaneous tunnel or including the supradiaphragmatic vagi within an implanted cooling jacket. In the fasted conscious dogs, we then studied the effect, on gastric tone, of acute and reversible vagal blockade by cooling. 3. Cervical vagal cooling produced a reversible gastric relaxation and increased the heart rate. Supradiaphragmatic vagal cooling produced a similar gastric relaxation without the cardiac effect. 4. Adrenergic blockade did not change either the base-line gastric tone or the cooling-induced relaxation. Adrenaline decreased gastric tone, but vagal cooling still produced a significant relaxation. 5. Atropine alone or combined with adrenergic antagonists produced a gastric relaxation that was not further increased by vagal cooling. Bethanechol increased gastric tone, an effect unchanged by vagal cooling. 6. We conclude that gastric tone during fasting is maintained by a cholinergic input, which is vagally mediated at both the cervical and the supradiaphragmatic levels. Images Fig. 1 PMID:2888879

The Role of Baseline Vagal Tone in Dealing with a Stressor during Face to Face and Computer-Based Social Interactions.

PubMed

Rigoni, Daniele; Morganti, Francesca; Braibanti, Paride

2017-01-01

Facing a stressor involves a cardiac vagal tone response and a feedback effect produced by social interaction in visceral regulation. This study evaluated the contribution of baseline vagal tone and of social engagement system (SES) functioning on the ability to deal with a stressor. Participants ( n = 70) were grouped into a minimized social interaction condition (procedure administered through a PC) and a social interaction condition (procedure administered by an experimenter). The State Trait Anxiety Inventory, the Social Interaction Anxiety Scale, the Emotion Regulation Questionnaire and a debriefing questionnaire were completed by the subjects. The baseline vagal tone was registered during the baseline, stressor and recovery phases. The collected results highlighted a significant effect of the baseline vagal tone on vagal suppression. No effect of minimized vs. social interaction conditions on cardiac vagal tone during stressor and recovery phases was detected. Cardiac vagal tone and the results of the questionnaires appear to be not correlated. The study highlighted the main role of baseline vagal tone on visceral regulation. Some remarks on SES to be deepen in further research were raised.

The Role of Baseline Vagal Tone in Dealing with a Stressor during Face to Face and Computer-Based Social Interactions

PubMed Central

Rigoni, Daniele; Morganti, Francesca; Braibanti, Paride

2017-01-01

Facing a stressor involves a cardiac vagal tone response and a feedback effect produced by social interaction in visceral regulation. This study evaluated the contribution of baseline vagal tone and of social engagement system (SES) functioning on the ability to deal with a stressor. Participants (n = 70) were grouped into a minimized social interaction condition (procedure administered through a PC) and a social interaction condition (procedure administered by an experimenter). The State Trait Anxiety Inventory, the Social Interaction Anxiety Scale, the Emotion Regulation Questionnaire and a debriefing questionnaire were completed by the subjects. The baseline vagal tone was registered during the baseline, stressor and recovery phases. The collected results highlighted a significant effect of the baseline vagal tone on vagal suppression. No effect of minimized vs. social interaction conditions on cardiac vagal tone during stressor and recovery phases was detected. Cardiac vagal tone and the results of the questionnaires appear to be not correlated. The study highlighted the main role of baseline vagal tone on visceral regulation. Some remarks on SES to be deepen in further research were raised. PMID:29234291

Activation of vagus nerve by semapimod alters substance P levels and decreases breast cancer metastasis.

PubMed

Erin, Nuray; Duymuş, Ozlem; Oztürk, Saffet; Demir, Necdet

2012-11-10

Chronic inflammation is involved in initiation as well as in progression of cancer. Semapimod, a tetravalent guanylhydrazon and formerly known as CNI-1493, inhibits the release of inflammatory cytokines from activated macrophages and this effect is partly mediated by the vagus nerve. Our previous findings demonstrated that inactivation of vagus nerve activity as well sensory neurons enhanced visceral metastasis of 4THM breast carcinoma. Hence semapimod by activating vagus nerve may inhibit breast cancer metastasis. Here, effects of semapimod on breast cancer metastasis, the role of vagal sensory neurons on this effect and changes in mediators of the neuroimmune connection, such as substance P (SP) as well as neprilysin-like activity, were examined. Vagotomy was performed on half of the control animals that were treated with semapimod following orthotopic injection of 4THM breast carcinoma cells. Semapimod decreased lung and liver metastases in control but not in vagotomized animals with an associated increased SP levels in sensory nerve endings. Semapimod also increased neprilysin-like activity in lung tissue of control animals but not in tumor-bearing animals. This is the first report demonstrating that semapimod enhances vagal sensory nerve activity and may have anti-tumoral effects under in-vivo conditions. Further studies, however, are required to elucidate the conditions and the mechanisms involved in anti-tumoral effects of semapimod. Copyright © 2012 Elsevier B.V. All rights reserved.

Lentiviral-mediated transfer of CDNF promotes nerve regeneration and functional recovery after sciatic nerve injury in adult rats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cheng, Lei; Liu, Yi; Zhao, Hua

Highlights: •CDNF was successfully transfected by a lentiviral vector into the distal sciatic nerve. •CDNF improved S-100, NF200 expression and nerve regeneration after sciatic injury. •CDNF improved the remyelination and thickness of the regenerated sciatic nerve. •CDNF improved gastrocnemius muscle weight and sciatic functional recovery. -- Abstract: Peripheral nerve injury is often followed by incomplete and unsatisfactory functional recovery and may be associated with sensory and motor impairment of the affected limb. Therefore, a novel method is needed to improve the speed of recovery and the final functional outcome after peripheral nerve injuries. This report investigates the effect of lentiviral-mediatedmore » transfer of conserved dopamine neurotrophic factor (CDNF) on regeneration of the rat peripheral nerve in a transection model in vivo. We observed notable overexpression of CDNF protein in the distal sciatic nerve after recombinant CDNF lentiviral vector application. We evaluated sciatic nerve regeneration after surgery using light and electron microscopy and the functional recovery using the sciatic functional index and target muscle weight. HE staining revealed better ordered structured in the CDNF-treated group at 8 weeks post-surgery. Quantitative analysis of immunohistochemistry of NF200 and S-100 in the CDNF group revealed significant improvement of axonal and Schwann cell regeneration compared with the control groups at 4 weeks and 8 weeks after injury. The thickness of the myelination around the axons in the CDNF group was significantly higher than in the control groups at 8 weeks post-surgery. The CDNF group displayed higher muscle weights and significantly increased sciatic nerve index values. Our findings suggest that CDNF gene therapy could provide durable and stable CDNF protein concentration and has the potential to enhance peripheral nerve regeneration, morphological and functional recovery following nerve injury, which

Effects of short and prolonged transcutaneous vagus nerve stimulation on heart rate variability in healthy subjects.

PubMed

De Couck, M; Cserjesi, R; Caers, R; Zijlstra, W P; Widjaja, D; Wolf, N; Luminet, O; Ellrich, J; Gidron, Y

2017-03-01

The vagus nerve is strategically located in the body, and has multiple homeostatic and health-promoting effects. Low vagal activity predicts onset and progression of diseases. These are the reasons to activate this nerve. This study examined the effects of transcutaneous vagus nerve stimulation (t-VNS) on a main index of vagal activity, namely heart rate variability (HRV). In Study 1, we compared short (10min) left versus right ear t-VNS versus sham (no stimulation) in a within-subjects experimental design. Results revealed significant increases in only one HRV parameter (standard deviation of the RR intervals (SDNN)) following right-ear t-VNS. Study 2 examined the prolonged effects of t-VNS (1h) in the right ear. Compared to baseline, right-t-VNS significantly increased the LF and LF/HF components of HRV, and SDNN in women, but not in men. These results show limited effects of t-VNS on HRV, and are discussed in light of neuroanatomical and statistical considerations and future directions are proposed. Copyright © 2016 Elsevier B.V. All rights reserved.

Vagal sensory innervation of the gastric sling muscle and antral wall: implications for gastro-esophageal reflux disease?

PubMed

Powley, T L; Gilbert, J M; Baronowsky, E A; Billingsley, C N; Martin, F N; Phillips, R J

2012-10-01

The gastric sling muscle has not been investigated for possible sensory innervation, in spite of the key roles the structure plays in lower esophageal sphincter (LES) function and gastric physiology. Thus, the present experiment used tracing techniques to label vagal afferents and survey their projections in the lesser curvature. Sprague-Dawley rats received injections of dextran biotin into the nodose ganglia. Fourteen days postinjection, animals were euthanized and their stomachs were processed to visualize the vagal afferent innervation. In different cases, neurons, muscle cells, or interstitial cells of Cajal (ICC) were counterstained. The sling muscle is innervated throughout its length by vagal afferent intramuscular arrays (IMAs) associated with ICC. In addition, the distal antral attachment site of the sling muscle is innervated by a novel vagal afferent terminal specialization, an antral web ending. The muscle wall of the distal antrum is also innervated by conventional IMAs and intraganglionic laminar endings, the two types of mechanoreceptors found throughout stomach smooth muscle. The innervation of sling muscle by IMAs, putative stretch receptors, suggests that sling sensory feedback may generate vago-vagal or other reflexes with vagal afferent limbs. The restricted distribution of afferent web endings near the antral attachments of sling fibers suggests the possibility of specialized mechanoreceptor functions linking antral and pyloric activity to the operation of the LES. Dysfunctional sling afferents could generate LES motor disturbances, or normative compensatory sensory feedback from the muscle could compromise therapies targeting only effectors. © 2012 Blackwell Publishing Ltd.

The role of precisely matching fascicles in the quick recovery of nerve function in long peripheral nerve defects

PubMed Central

Yan, Liwei; Yao, Zhi; Lin, Tao; Zhu, Qingtang; Qi, Jian; Gu, Liqiang; Fang, Jintao; Zhou, Xiang

2017-01-01

Peripheral nerve injury therapy in the clinic remains less than satisfactory. The gold standard of treatment for long peripheral nerve defects is autologous nerve grafts; however, numerous clinical complications are associated with this treatment. As tissue engineering has developed, tissue-engineered nerve grafts (TENGs) have shown potential applications as alternatives to autologous nerve grafts. To verify the important role of the biomimetic pathway of fascicle design in TENGs, we designed an animal model to study the role of the precise matching of fascicles in the effectiveness of nerve function recovery. 24 Sprague-Dawley rats were divided randomly into three groups (eight/group) that corresponded to 100% fascicle matching (100%FM), 50%FM and 0%FM. We selected Sprague–Dawley rat long-gap (15 mm) sciatic nerve defects. In the 6 weeks after surgery, we found that the 100%FM group showed the most effective functional recovery among the three groups. The 100%FM group showed better functional recovery on the basis of the sciatic functional index than the 50%FM and 0%FM groups. According to histological evaluation, the 100%FM group showed more regenerating nerve fibres. Moreover, in terms of the prevention of muscle atrophy, the 100%FM group showed excellent physiological outcomes. The 100%FM as tissue-engineered scaffolds can enhance nerve regeneration and effective functional recovery after the repair of large nerve defects. The results of this study provide a theoretical basis for future TENG designs including biomimetic fascicle pathways for repairing long nerve defects. PMID:28914740

Curcumin promotes nerve regeneration and functional recovery after sciatic nerve crush injury in diabetic rats.

PubMed

Ma, Junxiong; Yu, Hailong; Liu, Jun; Chen, Yu; Wang, Qi; Xiang, Liangbi

2016-01-01

Curcumin is capable of promoting peripheral nerve regeneration in normal condition. However, it is unclear whether its beneficial effect on nerve regeneration still exists under diabetic mellitus. The present study was designed to investigate such a possibility. Diabetes in rats was developed by a single dose of streptozotocin at 50 mg/kg. Immediately after nerve crush injury, the diabetic rats were intraperitoneally administrated daily for 4 weeks with curcumin (50 mg/kg, 100 mg/kg and 300 mg/kg), or normal saline, respectively. The axonal regeneration was investigated by morphometric analysis and retrograde labeling. The functional recovery was evaluated by electrophysiological studies and behavioral analysis. Axonal regeneration and functional recovery was significantly enhanced by curcumin, which were significantly better than those in vehicle saline group. In addition, high doses of curcumin (100 mg/kg and 300 mg/kg) achieved better axonal regeneration and functional recovery than low dose (50 mg/kg). In conclusion, curcumin is capable of promoting nerve regeneration after sciatic nerve crush injury in diabetes mellitus, highlighting its therapeutic values as a neuroprotective agent for peripheral nerve injury repair in diabetes mellitus. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Vagal tone as an index of mental state

NASA Technical Reports Server (NTRS)

Porges, Stephen W.

1988-01-01

The utility of monitoring oscillations in the heart rate pattern as a window to the brain is discussed as an index of general central nervous system status. Quantification of the amplitude of respiratory sinus arrhythmia provides an accurate index of cardiac vagal tone. A number of studies have demonstrated the validity of this measure; the relationship between flight performance and vagal tone has also been studied. In general, the vagal tone index appears to monitor global states of the central nervous system and may be useful in screening the general state of pilots.

Cardiac Vagal Regulation and Early Peer Status

ERIC Educational Resources Information Center

Graziano, Paulo A.; Keane, Susan P.; Calkins, Susan D.

2007-01-01

A sample of 341 5 1/2-year-old children participating in an ongoing longitudinal study was the focus of a study on the relation between cardiac vagal regulation and peer status. To assess cardiac vagal regulation, resting measures of respiratory sinus arrhythmia (RSA) and RSA change (suppression) to 3 cognitively and emotionally challenging tasks…

Influence of cigarette smoking on human autonomic function

NASA Technical Reports Server (NTRS)

Niedermaier, O. N.; Smith, M. L.; Beightol, L. A.; Zukowska-Grojec, Z.; Goldstein, D. S.; Eckberg, D. L.

1993-01-01

BACKGROUND. Although cigarette smoking is known to lead to widespread augmentation of sympathetic nervous system activity, little is known about the effects of smoking on directly measured human sympathetic activity and its reflex control. METHODS AND RESULTS. We studied the acute effects of smoking two research-grade cigarettes on muscle sympathetic nerve activity and on arterial baroreflex-mediated changes of sympathetic and vagal neural cardiovascular outflows in eight healthy habitual smokers. Measurements were made during frequency-controlled breathing, graded Valsalva maneuvers, and carotid baroreceptor stimulation with ramped sequences of neck pressure and suction. Smoking provoked the following changes: Arterial pressure increased significantly, and RR intervals, RR interval spectral power at the respiratory frequency, and muscle sympathetic nerve activity decreased. Plasma nicotine levels increased significantly, but plasma epinephrine, norepinephrine, and neuropeptide Y levels did not change. Peak sympathetic nerve activity during and systolic pressure overshoots after Valsalva straining increased significantly in proportion to increases of plasma nicotine levels. The average carotid baroreceptor-cardiac reflex relation shifted rightward and downward on arterial pressure and RR interval axes; average gain, operational point, and response range did not change. CONCLUSIONS. In habitual smokers, smoking acutely reduces baseline levels of vagal-cardiac nerve activity and completely resets vagally mediated arterial baroreceptor-cardiac reflex responses. Smoking also reduces muscle sympathetic nerve activity but augments increases of sympathetic activity triggered by brief arterial pressure reductions. This pattern of autonomic changes is likely to influence smokers' responses to acute arterial pressure reductions importantly.

Profiling of G protein-coupled receptors in vagal afferents reveals novel gut-to-brain sensing mechanisms.

PubMed

Egerod, Kristoffer L; Petersen, Natalia; Timshel, Pascal N; Rekling, Jens C; Wang, Yibing; Liu, Qinghua; Schwartz, Thue W; Gautron, Laurent

2018-06-01

G protein-coupled receptors (GPCRs) act as transmembrane molecular sensors of neurotransmitters, hormones, nutrients, and metabolites. Because unmyelinated vagal afferents richly innervate the gastrointestinal mucosa, gut-derived molecules may directly modulate the activity of vagal afferents through GPCRs. However, the types of GPCRs expressed in vagal afferents are largely unknown. Here, we determined the expression profile of all GPCRs expressed in vagal afferents of the mouse, with a special emphasis on those innervating the gastrointestinal tract. Using a combination of high-throughput quantitative PCR, RNA sequencing, and in situ hybridization, we systematically quantified GPCRs expressed in vagal unmyelinated Na v 1.8-expressing afferents. GPCRs for gut hormones that were the most enriched in Na v 1.8-expressing vagal unmyelinated afferents included NTSR1, NPY2R, CCK1R, and to a lesser extent, GLP1R, but not GHSR and GIPR. Interestingly, both GLP1R and NPY2R were coexpressed with CCK1R. In contrast, NTSR1 was coexpressed with GPR65, a marker preferentially enriched in intestinal mucosal afferents. Only few microbiome-derived metabolite sensors such as GPR35 and, to a lesser extent, GPR119 and CaSR were identified in the Na v 1.8-expressing vagal afferents. GPCRs involved in lipid sensing and inflammation (e.g. CB1R, CYSLTR2, PTGER4), and neurotransmitters signaling (CHRM4, DRD2, CRHR2) were also highly enriched in Na v 1.8-expressing neurons. Finally, we identified 21 orphan GPCRs with unknown functions in vagal afferents. Overall, this study provides a comprehensive description of GPCR-dependent sensing mechanisms in vagal afferents, including novel coexpression patterns, and conceivably coaction of key receptors for gut-derived molecules involved in gut-brain communication. Copyright © 2018 The Authors. Published by Elsevier GmbH.. All rights reserved.

Functional restoration of the paralyzed diaphragm in high cervical quadriplegia via phrenic nerve neurotization utilizing the functional spinal accessory nerve.

PubMed

Yang, Ming-liang; Li, Jian-jun; Zhang, Shao-cheng; Du, Liang-jie; Gao, Feng; Li, Jun; Wang, Yu-ming; Gong, Hui-ming; Cheng, Liang

2011-08-01

The authors report a case of functional improvement of the paralyzed diaphragm in high cervical quadriplegia via phrenic nerve neurotization using a functional spinal accessory nerve. Complete spinal cord injury at the C-2 level was diagnosed in a 44-year-old man. Left diaphragm activity was decreased, and the right diaphragm was completely paralyzed. When the level of metabolism or activity (for example, fever, sitting, or speech) slightly increased, dyspnea occurred. The patient underwent neurotization of the right phrenic nerve with the trapezius branch of the right spinal accessory nerve at 11 months postinjury. Four weeks after surgery, training of the synchronous activities of the trapezius muscle and inspiration was conducted. Six months after surgery, motion was observed in the previously paralyzed right diaphragm. The lung function evaluation indicated improvements in vital capacity and tidal volume. This patient was able to sit in a wheelchair and conduct outdoor activities without assisted ventilation 12 months after surgery.

Microscale Electrode Implantation during Nerve Repair: Effects on Nerve Morphology, Electromyography, and Recovery of Muscle Contractile Function

PubMed Central

Urbanchek, Melanie G; Wei, Benjamin; Egeland, Brent M; Abidian, Mohammad R; Kipke, Daryl R; Cederna, Paul S

2011-01-01

Background Our goal is to develop a peripheral nerve electrode with long-term stability and fidelity for use in nerve-machine interfaces. Microelectromechanical systems (MEMS) use silicon probes that contain multi-channel actuators, sensors, and electronics. We tested the null hypothesis that implantation of MEMS probes do not have a detrimental effect on peripheral nerve function or regeneration. Methods A rat hindlimb, peroneal nerve model was utilized in all experimental groups: a) intact nerve (Control, n= 10); b) nerve division and repair (Repair, n= 9); and c) Nerve division, insertion of MEMS probe, and repair (Repair + Probe, n=9). Nerve morphology, nerve to muscle compound action potential (CMAP) studies, walking tracks, and extensor digitorum longus (EDL) muscle function tests were evaluated following an 80 day recovery. Results Repair and Repair + Probe showed no differences in axon count, axon size, percent non-neural area, CMAP amplitude, latency, muscle mass, muscle force, or walking track scores. Though there was some local fibrosis around each MEMS probe, this did not lead to measurable detrimental effects in any anatomic or functional outcome measurements. Conclusions The lack of a significant difference between Repair and Repair + Probe groups in histology, CMAP, walking tracks, and muscle force suggests that MEMS electrodes are compatible with regenerating axons and show promise for establishing chemical and electrical interfaces with peripheral nerves. PMID:21921739

Role of the vagal afferents in substance P-induced respiratory responses in anaesthetized rabbits.

PubMed

Prabhakar, N R; Runold, M; Yamamoto, Y; Lagercrantz, H; Cherniack, N S; von Euler, C

1987-09-01

Since substance P (SP)-like immunoreactivity has been demonstrated in vagal sensory fibres of bronchopulmonary origin, it was considered of interest to (1) characterize the pattern of responses to SP injected into the pulmonary as well as the systemic arterial system, and (2) assess the types of vagal afferents that are affected by SP. Experiments were performed on 15 pentobarbital-anaesthetized, spontaneously breathing rabbits. Efferent phrenic nerve activity was monitored as an index of central respiratory neural output. Intra-atrial injections of SP into the pulmonary circulation (100 ng kg-1) increased the respiratory rate, and peak integrated phrenic amplitude by 47 +/- 8 and 40 +/- 4%, respectively, above the controls. In addition, SP elicited augmented breaths (ABs) within 2-3 s in 67% of the trials. In contrast to right atrial injections, no ABs and no significant changes in respiratory rate were observed in response to intra-aortic injections of SP (100 ng kg-1). Tidal phrenic activity rise after aortic injections of SP was significantly less as compared with right atrial administrations of SP. Since both routes of administration decreased the arterial blood pressure to the same extent, these respiratory responses were not likely secondary to cardiovascular changes. After administration of an SP antagonist (D-Arg-D-Trp7,9, Leu11, SP), respiratory responses to SP were significantly attenuated. Also, the rate of occurrence of ABs elicited by releasing the tracheal occlusions was reduced (control 95 vs. 14% SP antagonist). Bilateral vagotomy abolished the tachypnoeic response and reduced the magnitude of the phrenic nerve increments caused by right atrial injection of SP.(ABSTRACT TRUNCATED AT 250 WORDS)

Less Empathic and More Reactive: The Different Impact of Childhood Maltreatment on Facial Mimicry and Vagal Regulation

PubMed Central

Ardizzi, Martina; Umiltà, Maria Alessandra; Evangelista, Valentina; Di Liscia, Alessandra; Ravera, Roberto; Gallese, Vittorio

2016-01-01

Facial mimicry and vagal regulation represent two crucial physiological responses to others’ facial expressions of emotions. Facial mimicry, defined as the automatic, rapid and congruent electromyographic activation to others’ facial expressions, is implicated in empathy, emotional reciprocity and emotions recognition. Vagal regulation, quantified by the computation of Respiratory Sinus Arrhythmia (RSA), exemplifies the autonomic adaptation to contingent social cues. Although it has been demonstrated that childhood maltreatment induces alterations in the processing of the facial expression of emotions, both at an explicit and implicit level, the effects of maltreatment on children’s facial mimicry and vagal regulation in response to facial expressions of emotions remain unknown. The purpose of the present study was to fill this gap, involving 24 street-children (maltreated group) and 20 age-matched controls (control group). We recorded their spontaneous facial electromyographic activations of corrugator and zygomaticus muscles and RSA responses during the visualization of the facial expressions of anger, fear, joy and sadness. Results demonstrated a different impact of childhood maltreatment on facial mimicry and vagal regulation. Maltreated children did not show the typical positive-negative modulation of corrugator mimicry. Furthermore, when only negative facial expressions were considered, maltreated children demonstrated lower corrugator mimicry than controls. With respect to vagal regulation, whereas maltreated children manifested the expected and functional inverse correlation between RSA value at rest and RSA response to angry facial expressions, controls did not. These results describe an early and divergent functional adaptation to hostile environment of the two investigated physiological mechanisms. On the one side, maltreatment leads to the suppression of the spontaneous facial mimicry normally concurring to empathic understanding of others�

Human sinus arrhythmia as an index of vagal cardiac outflow

NASA Technical Reports Server (NTRS)

Eckberg, D. L.

1983-01-01

The human central vagal mechanisms were investigated by measuring the intervals between heartbeats during controlled breathing (at breathing intervals of 2.5-10 s and nominal tidal volumes of 1000 and 1500 ml) in six young men and women. It was found that as the breathing interval increased, the longest heart periods became longer, the shortest heart periods became shorter, and the peak-valley P-P intervals increased asymptotically. Peak-valley intervals also increased in proportion to tidal volume, although this influence was small. The phase angles between heart period changes and respiration were found to vary as linear functions of breathing interval. Heart period shortening began in inspiration at short breathing intervals and in expiration at long breathing intervals, while heart period lengthening began in early expiration at all breathing intervals studied. It is concluded that a close relationship exists between variations of respiratory depth and interval and the quantity, periodicity, and timing of vagal cardiac outflow in conscious humans. The results indicate that at usual breathing rates, phasic respiration-related changes of vagal motoneuron activity begin in expiration, progress slowly, and are incompletely expressed at fast breathing ratges.

Exercise training preserves vagal preganglionic neurones and restores parasympathetic tonus in heart failure.

PubMed

Ichige, Marcelo H A; Santos, Carla R; Jordão, Camila P; Ceroni, Alexandre; Negrão, Carlos E; Michelini, Lisete C

2016-11-01

Heart Failure (HF) is accompanied by reduced ventricular function, activation of compensatory neurohormonal mechanisms and marked autonomic dysfunction characterized by exaggerated sympathoexcitation and reduced parasympathetic activity. With 6 weeks of exercise training, HF-related loss of choline acetyltransferase (ChAT)-positive vagal preganglionic neurones is avoided, restoring the parasympathetic tonus to the heart, and the immunoreactivity of dopamine β-hydroxylase-positive premotor neurones that drive sympathetic outflow to the heart is reduced. Training-induced correction of autonomic dysfunction occurs even with the persistence of abnormal ventricular function. Strong positive correlation between improved parasympathetic tonus to the heart and increased ChAT immunoreactivity in vagal preganglionic neurones after training indicates this is a crucial mechanism to restore autonomic function in heart failure. Exercise training is an efficient tool to attenuate sympathoexcitation, a hallmark of heart failure (HF). Although sympathetic modulation in HF is widely studied, information regarding parasympathetic control is lacking. We examined the combined effects of sympathetic and vagal tonus to the heart in sedentary (Sed) and exercise trained (ET) HF rats and the contribution of respective premotor and preganglionic neurones. Wistar rats submitted to coronary artery ligation or sham surgery were assigned to training or sedentary protocols for 6 weeks. After haemodynamic, autonomic tonus (atropine and atenolol i.v.) and ventricular function determinations, brains were collected for immunoreactivity assays (choline acetyltransferase, ChATir; dopamine β-hydroxylase, DBHir) and neuronal counting in the dorsal motor nucleus of vagus (DMV), nucleus ambiguus (NA) and rostroventrolateral medulla (RVLM). HF-Sed vs. SHAM-Sed exhibited decreased exercise capacity, reduced ejection fraction, increased left ventricle end diastolic pressure, smaller positive and negative

Optogenetic probing of nerve and muscle function after facial nerve lesion in the mouse whisker system

NASA Astrophysics Data System (ADS)

Bandi, Akhil; Vajtay, Thomas J.; Upadhyay, Aman; Yiantsos, S. Olga; Lee, Christian R.; Margolis, David J.

2018-02-01

Optogenetic modulation of neural circuits has opened new avenues into neuroscience research, allowing the control of cellular activity of genetically specified cell types. Optogenetics is still underdeveloped in the peripheral nervous system, yet there are many applications related to sensorimotor function, pain and nerve injury that would be of great benefit. We recently established a method for non-invasive, transdermal optogenetic stimulation of the facial muscles that control whisker movements in mice (Park et al., 2016, eLife, e14140)1. Here we present results comparing the effects of optogenetic stimulation of whisker movements in mice that express channelrhodopsin-2 (ChR2) selectively in either the facial motor nerve (ChAT-ChR2 mice) or muscle (Emx1-ChR2 or ACTA1-ChR2 mice). We tracked changes in nerve and muscle function before and up to 14 days after nerve transection. Optogenetic 460 nm transdermal stimulation of the distal cut nerve showed that nerve degeneration progresses rapidly over 24 hours. In contrast, the whisker movements evoked by optogenetic muscle stimulation were up-regulated after denervation, including increased maximum protraction amplitude, increased sensitivity to low-intensity stimuli, and more sustained muscle contractions (reduced adaptation). Our results indicate that peripheral optogenetic stimulation is a promising technique for probing the timecourse of functional changes of both nerve and muscle, and holds potential for restoring movement after paralysis induced by nerve damage or motoneuron degeneration.

Vagal innervation of the aldosterone-sensitive HSD2 neurons in the NTS

PubMed Central

Shin, Jung-Won; Geerling, Joel C.; Loewy, Arthur D.

2009-01-01

The nucleus of the solitary tract (NTS) contains a unique subpopulation of aldosterone-sensitive neurons. These neurons express the enzyme 11-β-hydroxysteroid dehydrogenase type 2 (HSD2) and are activated by sodium deprivation. They are located in the caudal NTS, a region which is densely innervated by the vagus nerve, suggesting that they could receive direct viscerosensory input from the periphery. To test this possibility, we injected the highly sensitive axonal tracer biotinylated dextran amine (BDA) into the left nodose ganglion in rats. Using confocal microscopy, we observed a sparse input from the vagus to most HSD2 neurons. Roughly 80% of the ipsilateral HSD2 neurons exhibited at least one close contact with a BDA-labeled vagal bouton, although most of these cells received only a few total contacts. Most of these contacts were axo-dendritic (~80%), while ~20% were axo-somatic. In contrast, the synaptic vesicular transporters VGLUT2 or GAD7 labeled much larger populations of boutons contacting HSD2-labeled dendrites and somata, suggesting that direct input from the vagus may only account for a minority of the information integrated by these neurons. In summary, the aldosterone-sensitive HSD2 neurons in the NTS appear to receive a small amount of direct viscerosensory input from the vagus nerve. The peripheral sites of origin and functional significance of this projection remain unknown. Combined with previously-identified central sources of input to these cells, the present finding indicates that the HSD2 neurons integrate humoral information with input from a variety of neural afferents. PMID:19010311

Expression of Sex Steroid Hormone Receptors in Vagal Motor Neurons Innervating the Trachea and Esophagus in Mouse

PubMed Central

Mukudai, Shigeyuki; Ichi Matsuda, Ken; Bando, Hideki; Takanami, Keiko; Nishio, Takeshi; Sugiyama, Yoichiro; Hisa, Yasuo; Kawata, Mitsuhiro

2016-01-01

The medullary vagal motor nuclei, the nucleus ambiguus (NA) and dorsal motor nucleus of the vagus (DMV), innervate the respiratory and gastrointestinal tracts. We conducted immunohistochemical analysis of expression of the androgen receptor (AR) and estrogen receptor α (ERα), in relation to innervation of the trachea and esophagus via vagal motor nuclei in mice. AR and ERα were expressed in the rostral NA and in part of the DMV. Tracing experiments using cholera toxin B subunit demonstrated that neurons of vagal motor nuclei that innervate the trachea and esophagus express AR and ERα. There was no difference in expression of sex steroid hormone receptors between trachea- and esophagus-innervating neurons. These results suggest that sex steroid hormones may act on vagal motor nuclei via their receptors, thereby regulating functions of the trachea and esophagus. PMID:27006520

Assessment of recurrent laryngeal nerve function during thyroid surgery.

PubMed

Smith, J; Douglas, J; Smith, B; Dougherty, T; Ayshford, C

2014-03-01

There is disparity in the reported incidence of temporary and permanent recurrent laryngeal nerve (RLN) palsy following thyroidectomy. Much of the disparity is due to the method of assessing vocal cord function. We sought to identify the incidence and natural history of temporary and permanent vocal cord palsy following thyroid surgery. The authors wanted to establish whether intraoperative nerve monitoring and stimulation aids in prognosis when managing vocal cord palsy. Prospective data on consecutive thyroid operations were collected. Intraoperative nerve monitoring and stimulation, using an endotracheal tube mounted device, was performed in all cases. Endoscopic examination of the larynx was performed on the first postoperative day and at three weeks. Data on 102 patients and 123 nerves were collated. Temporary and permanent RLN palsy rates were 6.1% and 1.7%. Most RLN palsies were identified on the first postoperative day with all recognised at the three-week review. No preoperative clinical risk factors were identified. Although dysphonia at the three-week follow-up visit was the only significant predictor of vocal cord palsy, only two-thirds of patients with cord palsies were dysphonic. Intraoperative nerve monitoring and stimulation did not predict outcome in terms of vocal cord function. Temporary nerve palsy rates were consistent with other series where direct laryngoscopy is used to assess laryngeal function. Direct laryngoscopy is the only reliable measure of cord function, with intraoperative monitoring being neither a reliable predictor of cord function nor a predictor of eventual laryngeal function. The fact that all temporary palsies recovered within four months has implications for staged procedures.

Pyridostigmine protects against cardiomyopathy associated with adipose tissue browning and improvement of vagal activity in high-fat diet rats.

PubMed

Lu, Yi; Wu, Qing; Liu, Long-Zhu; Yu, Xiao-Jiang; Liu, Jin-Jun; Li, Man-Xiang; Zang, Wei-Jin

2018-04-01

Obesity, a major contributor to the development of cardiovascular diseases, is associated with an autonomic imbalance characterized by sympathetic hyperactivity and diminished vagal activity. Vagal activation plays important roles in weight loss and improvement of cardiac function. Pyridostigmine is a reversible acetylcholinesterase inhibitor, but whether it ameliorates cardiac lipid accumulation and cardiac remodeling in rats fed a high-fat diet has not been determined. This study investigated the effects of pyridostigmine on high-fat diet-induced cardiac dysfunction and explored the potential mechanisms. Rats were fed a normal or high-fat diet and treated with pyridostigmine. Vagal discharge was evaluated using the BL-420S system, and cardiac function by echocardiograms. Lipid deposition and cardiac remodeling were determined histologically. Lipid utility was assessed by qPCR. A high-fat diet led to a significant reduction in vagal discharge and lipid utility and a marked increase in lipid accumulation, cardiac remodeling, and cardiac dysfunction. Pyridostigmine improved vagal activity and lipid metabolism disorder and cardiac remodeling, accompanied by an improvement of cardiac function in high-fat diet-fed rats. An increase in the browning of white adipose tissue in pyridostigmine-treated rats was also observed and linked to the expression of UCP-1 and CIDEA. Additionally, pyridostigmine facilitated activation of brown adipose tissue via activation of the SIRT-1/AMPK/PGC-1α pathway. In conclusion, a high-fat diet resulted in cardiac lipid accumulation, cardiac remodeling, and a significant decrease in vagal discharge. Pyridostigmine ameliorated cardiomyopathy, an effect related to reduced cardiac lipid accumulation, and facilitated the browning of white adipose tissue while activating brown adipose tissue. Copyright © 2018 Elsevier B.V. All rights reserved.

Length of nerve gap defects correlates with incidence of nerve regeneration but not with recovery of taste function in patients with severed chorda tympani nerve.

PubMed

Saito, Takehisa; Narita, Norihiko; Yamada, Takechiyo; Ogi, Kazuhiro; Kanno, Masafumi; Manabe, Yasuhiro; Ito, Tetsufumi

2011-10-01

To evaluate the relationship between the length of nerve gap defects, incidence of nerve regeneration, and recovery of gustatory function after severing the chorda tympani nerve (CTN). Retrospective study. University hospital. Eighty-eight consecutive patients whose CTNs were severed during primary surgery and who underwent secondary surgery were included. Proximal and distal stumps of severed nerves were readapted or approximated during surgery. Therapeutic. Before and after surgery, the taste function was periodically evaluated using electrogustometry. Nerve gaps were classified into 4 groups: readaptation (Group 1), 1 to 3 mm (Group 2), 4 to 6 mm (Group 3), and more than 7 mm (Group 4). Regenerated nerves in the tympanic segment were detected in 36 (41%) of the 88 patients during secondary surgery. The incidence of nerve regeneration was 100% (10/10) in Group 1, 45% (10/22) in Group 2, 47% (9/19) in Group 3, and 19% (7/37) in Group 4. There was a significant difference between the length of nerve gap defects and incidence of nerve regeneration (p < 0.001). In the 36 patients with a regenerated CTN, the incidence of gustatory function recovery was 60% (6/10) in Group 1, 50% (5/10) in Group 2, 56% (5/9) in Group 3, and 43% (3/7) in Group 4. There was no significant difference between the length of nerve gap defects and incidence of taste function recovery. Reconstruction of a severed CTN is very important for regeneration. However, the regenerated CTN in the tympanic segment does not always reinnervate the fungiform papillae.

The EMPOWER study: randomized, prospective, double-blind, multicenter trial of vagal blockade to induce weight loss in morbid obesity.

PubMed

Sarr, Michael G; Billington, Charles J; Brancatisano, Roy; Brancatisano, Anthony; Toouli, James; Kow, Lilian; Nguyen, Ninh T; Blackstone, Robin; Maher, James W; Shikora, Scott; Reeds, Dominic N; Eagon, J Christopher; Wolfe, Bruce M; O'Rourke, Robert W; Fujioka, Ken; Takata, Mark; Swain, James M; Morton, John M; Ikramuddin, Sayeed; Schweitzer, Michael; Chand, Bipan; Rosenthal, Raul

2012-11-01

Intermittent, reversible intraabdominal vagal blockade (VBLOC® Therapy) demonstrated clinically important weight loss in feasibility trials. EMPOWER, a randomized, double-blind, prospective, controlled trial was conducted in USA and Australia. Five hundred three subjects were enrolled at 15 centers. After informed consent, 294 subjects were implanted with the vagal blocking system and randomized to the treated (n = 192) or control (n = 102) group. Main outcome measures were percent excess weight loss (percent EWL) at 12 months and serious adverse events. Subjects controlled duration of therapy using an external power source; therapy involved a programmed algorithm of electrical energy delivered to the subdiaphragmatic vagal nerves to inhibit afferent/efferent vagal transmission. Devices in both groups performed regular, low-energy safety checks. Data are mean ± SEM. Study subjects consisted of 90 % females, body mass index of 41 ± 1 kg/m(2), and age of 46 ± 1 years. Device-related complications occurred in 3 % of subjects. There was no mortality. 12-month percent EWL was 17 ± 2 % for the treated and 16 ± 2 % for the control group. Weight loss was related linearly to hours of device use; treated and controls with ≥ 12 h/day use achieved 30 ± 4 and 22 ± 8 % EWL, respectively. VBLOC® therapy to treat morbid obesity was safe, but weight loss was not greater in treated compared to controls; clinically important weight loss, however, was related to hours of device use. Post-study analysis suggested that the system electrical safety checks (low charge delivered via the system for electrical impedance, safety, and diagnostic checks) may have contributed to weight loss in the control group.

Increased Vagal Tone and Sleep Apnea Syndrome.

PubMed

Ahmed, Tosaddak

2016-01-01

It has been observed that atrial overdrive pacing abolishes sleep apnea syndrome, but how it does so has not been explained. There is a possibility that it sends a retrograde inhibitory impulse to the vagal center in the brainstem, which in turn reduces the vagal tone, and thus prevents sleep apnea. Therefore, medical vagolytics such as atropine type of drugs should have the same effect. This is a case report of such an attempt.

Assessment of recurrent laryngeal nerve function during thyroid surgery

PubMed Central

Douglas, J; Smith, B; Dougherty, T; Ayshford, C

2014-01-01

Introduction There is disparity in the reported incidence of temporary and permanent recurrent laryngeal nerve (RLN) palsy following thyroidectomy. Much of the disparity is due to the method of assessing vocal cord function. We sought to identify the incidence and natural history of temporary and permanent vocal cord palsy following thyroid surgery. The authors wanted to establish whether intraoperative nerve monitoring and stimulation aids in prognosis when managing vocal cord palsy. Methods Prospective data on consecutive thyroid operations were collected. Intraoperative nerve monitoring and stimulation, using an endotracheal tube mounted device, was performed in all cases. Endoscopic examination of the larynx was performed on the first postoperative day and at three weeks. Results Data on 102 patients and 123 nerves were collated. Temporary and permanent RLN palsy rates were 6.1% and 1.7%. Most RLN palsies were identified on the first postoperative day with all recognised at the three-week review. No preoperative clinical risk factors were identified. Although dysphonia at the three-week follow-up visit was the only significant predictor of vocal cord palsy, only two-thirds of patients with cord palsies were dysphonic. Intraoperative nerve monitoring and stimulation did not predict outcome in terms of vocal cord function. Conclusions Temporary nerve palsy rates were consistent with other series where direct laryngoscopy is used to assess laryngeal function. Direct laryngoscopy is the only reliable measure of cord function, with intraoperative monitoring being neither a reliable predictor of cord function nor a predictor of eventual laryngeal function. The fact that all temporary palsies recovered within four months has implications for staged procedures. PMID:24780671

Processing of central and reflex vagal drives by rat cardiac ganglion neurones: an intracellular analysis

PubMed Central

McAllen, Robin M; Salo, Lauren M; Paton, Julian F R; Pickering, Anthony E

2011-01-01

Abstract Cardiac vagal tone is an important indicator of cardiovascular health, and its loss is an independent risk factor for arrhythmias and mortality. Several studies suggest that this loss of vagal tone can occur at the cardiac ganglion but the factors affecting ganglionic transmissionin vivoare poorly understood. We have employed a novel approach allowing intracellular recordings from functionally connected cardiac vagal ganglion cells in the working heart–brainstem preparation. The atria were stabilisedin situpreserving their central neural connections, and ganglion cells (n = 32) were impaled with sharp microelectrodes. Cardiac ganglion cells with vagal synaptic inputs (spontaneous, n = 10; or electrically evoked from the vagus, n = 3) were identified as principal neurones and showed tonic firing responses to current injected to their somata. Cells lacking vagal inputs (n = 19, presumed interneurones) were quiescent but showed phasic firing responses to depolarising current. In principal cells the ongoing action potentials and EPSPs exhibited respiratory modulation, with peak frequency in post-inspiration. Action potentials arose from unitary EPSPs and autocorrelation of those events showed that each ganglion cell received inputs from a single active preganglionic source. Peripheral chemoreceptor, arterial baroreceptor and diving response activation all evoked high frequency synaptic barrages in these cells, always from the same single preganglionic source. EPSP amplitudes showed frequency dependent depression, leading to more spike failures at shorter inter-event intervals. These findings indicate that rather than integrating convergent inputs, cardiac vagal postganglionic neurones gate preganglionic inputs, so regulating the proportion of central parasympathetic tone that is transmitted on to the heart. PMID:22005679

Effect of vagotomy and vagal cooling on bronchoconstrictor response to substance P in sheep.

PubMed

Corcoran, B M; Haigh, A L

1995-10-01

The bronchoconstrictor effect of intravenous substance P can be antagonised by atropine pre-treatment in several species, and we have previously reported this finding in anaesthetised sheep. In the present study, we have assessed the effect of cooling the right vagus after sectioning the left vagus (n = 6), and bilateral vagotomy (n = 7) on the bronchoconstrictor response to a single intravenous dose of substance P (SP) (0.3-1.0 mumol/kg) in anaesthetized female sheep aged 6 to 12 months. Respiratory parameters including tidal volume, flow and transpulmonary pressure pressure were measured, from which pulmonary resistance (RL; cmH2O.1(-1).s) and dynamic compliance (CDyn; ml.cmH2O(-1) were calculated. Systemic arterial pressures were also measured. Vagal cooling significantly attenuated the bronchoconstrictor response to SP at 7 degrees C (RL P < 0.01; Cdyn P < 0.001). A further reduction in the response to SP occurred at 3 degrees C, but this was not statistically significantly different from the response at 7 degrees C. Vagotomy abolished the response to SP. SP caused mild, but statistically insignificant, hypotension (119.7 vs. 107.7 mmHg). These results suggest SP causes bronchoconstriction in the anaesthetised sheep by vagal reflex mechanisms, involving stimulation of myelinated nerve fibre endings.

The vagal ganglia transcriptome identifies candidate therapeutics for airway hyperreactivity.

PubMed

Reznikov, Leah R; Meyerholz, David K; Abou Alaiwa, Mahmoud H; Kuan, Shin-Ping; Liao, Yan-Shin J; Bormann, Nicholas L; Bair, Thomas B; Price, Margaret; Stoltz, David A; Welsh, Michael J

2018-04-05

Mainstay therapeutics are ineffective in some people with asthma, suggesting a need for additional agents. In the current study, we used vagal ganglia transcriptome profiling and connectivity mapping to identify compounds beneficial for alleviating airway hyperreactivity. As a comparison, we also utilized previously published transcriptome data from sensitized mouse lungs and human asthmatic endobronchial biopsies. All transcriptomes revealed agents beneficial for mitigating airway hyperreactivity; however, only the vagal ganglia transcriptome identified agents used clinically to treat asthma (flunisolide, isoetarine). We also tested one compound identified by vagal ganglia transcriptome profiling that had not previously been linked to asthma and found that it had bronchodilator effects in both mouse and pig airways. These data suggest that transcriptome profiling of the vagal ganglia might be a novel strategy to identify potential asthma therapeutics.

Moderate Baseline Vagal Tone Predicts Greater Prosociality in Children

ERIC Educational Resources Information Center

Miller, Jonas G.; Kahle, Sarah; Hastings, Paul D.

2017-01-01

Vagal tone is widely believed to be an important physiological aspect of emotion regulation and associated positive behaviors. However, there is inconsistent evidence for relations between children's baseline vagal tone and their helpful or prosocial responses to others (Hastings & Miller, 2014). Recent work in adults suggests a quadratic…

Neuroendocrine responses to stimulation of the vagus nerves in bursts in conscious calves.

PubMed

Adrian, T E; Bloom, S R; Edwards, A V

1983-11-01

Effects of stimulation of the peripheral ends of the vagus nerves below the heart at 4 Hz continuously, and at 40 Hz for 1 s at 10 s intervals, have been compared in conscious calves below behavioural threshold. Neither pattern of stimulation caused any significant change in mean aortic blood pressure or heart rate but both invariably produced a substantial increase in the flow of intestinal lymph. Each form of stimulation provoked release of glucagon, insulin and pancreatic polypeptide from the pancreas and produced a small but significant rise in mean arterial plasma glucose concentration. The release of gastric inhibitory peptide- and bombesin-like molecules from the gastrointestinal tract was not affected by vagal stimulation whereas release of vasoactive intestinal peptide was observed in response to both patterns of vagal stimulation. Evidence was obtained to suggest that gastrin-like peptides are preferentially released into the bloodstream whereas cholecystokinin-like peptides are not. Vagal stimulation releases somatostatin from the gastrointestinal tract but discontinuous stimulation seems to inhibit the release of somatostatin into the general circulation. The results that have been obtained, employing this particular protocol, suggest that the pattern of the stimulus that is applied to the vagal splanchnic innervation has relatively little effect on neuroendocrine response in this species.

Neuroendocrine responses to stimulation of the vagus nerves in bursts in conscious calves.

PubMed Central

Adrian, T E; Bloom, S R; Edwards, A V

1983-01-01

Effects of stimulation of the peripheral ends of the vagus nerves below the heart at 4 Hz continuously, and at 40 Hz for 1 s at 10 s intervals, have been compared in conscious calves below behavioural threshold. Neither pattern of stimulation caused any significant change in mean aortic blood pressure or heart rate but both invariably produced a substantial increase in the flow of intestinal lymph. Each form of stimulation provoked release of glucagon, insulin and pancreatic polypeptide from the pancreas and produced a small but significant rise in mean arterial plasma glucose concentration. The release of gastric inhibitory peptide- and bombesin-like molecules from the gastrointestinal tract was not affected by vagal stimulation whereas release of vasoactive intestinal peptide was observed in response to both patterns of vagal stimulation. Evidence was obtained to suggest that gastrin-like peptides are preferentially released into the bloodstream whereas cholecystokinin-like peptides are not. Vagal stimulation releases somatostatin from the gastrointestinal tract but discontinuous stimulation seems to inhibit the release of somatostatin into the general circulation. The results that have been obtained, employing this particular protocol, suggest that the pattern of the stimulus that is applied to the vagal splanchnic innervation has relatively little effect on neuroendocrine response in this species. PMID:6361233

The role of nerve monitoring to predict postoperative recurrent laryngeal nerve function in thyroid and parathyroid surgery.

PubMed

Eid, Issam; Miller, Frank R; Rowan, Stephanie; Otto, Randal A

2013-10-01

To determine the role and efficacy of intraoperative recurrent laryngeal nerve (RLN) stimulation in the prediction of early and permanent postoperative nerve function in thyroid and parathyroid surgery. A retrospective review of thyroid and parathyroid surgeries was performed with calculation of sensitivity and specificity of the response of intraoperative stimulation for different pathological groups. Normal electromyography (EMG) response with 0.5 mAmp stimulation was considered a positive stimulation response with postoperative function determined by laryngoscopy. No EMG response at >1-2 mAmps was considered a negative response. The rates of early and permanent paralysis, as well as sensitivity, specificity, and positive and negative predictive values for postoperative nerve function were calculated for separate pathological groups. The number of nerves at risk analyzed was 909. The overall early and permanent paralysis rates were 3.1% and 1.2%, respectively, with the highest rate being for Grave's disease cases. The overall sensitivity was 98.4%. The specificity was lower at 62.5% but acceptable in thyroid carcinoma and Grave's disease patients. The majority of nerves with a positive stimulation result and postoperative paralysis on laryngoscopy recovered function in 3 to 12 weeks, showing positive stimulation to be a good predictor of eventual recovery. Stimulation of the RLN during thyroid and parathyroid surgery is a useful tool in predicting postoperative RLN function. The sensitivity of stimulation is high, showing positive stimulation to be an excellent predictor of normal nerve function. Negative stimulation is more predictive of paralysis in cases of thyroid carcinoma and Grave's disease. 2b. Copyright © 2013 The American Laryngological, Rhinological and Otological Society, Inc.

Timeline: exorcizing the animal spirits: Jan Swammerdam on nerve function.

PubMed

Cobb, M

2002-05-01

For more than 1,500 years, nerves were thought to function through the action of 'animal spirits'. In the seventeenth century, René Descartes conceived of these 'spirits' as liquids or gases, and used the idea to explain reflex action. But he was rapidly proven wrong by a young Dutchman, Jan Swammerdam. Swammerdam's elegant experiments pioneered the frog nerve muscle preparation and laid the foundation of our modern understanding of nerve function.

Sensory and motor peripheral nerve function and incident mobility disability.

PubMed

Ward, Rachel E; Boudreau, Robert M; Caserotti, Paolo; Harris, Tamara B; Zivkovic, Sasa; Goodpaster, Bret H; Satterfield, Suzanne; Kritchevsky, Stephen B; Schwartz, Ann V; Vinik, Aaron I; Cauley, Jane A; Simonsick, Eleanor M; Newman, Anne B; Strotmeyer, Elsa S

2014-12-01

To assess the relationship between sensorimotor nerve function and incident mobility disability over 10 years. Prospective cohort study with longitudinal analysis. Two U.S. clinical sites. Population-based sample of community-dwelling older adults with no mobility disability at 2000/01 examination (N = 2,148 [Corrected]; mean age ± SD 76.5 ± 2.9, body mass index 27.1 ± 4.6; 50.2% female, 36.6% black, 10.7% with diabetes mellitus). Motor nerve conduction amplitude (poor <1 mV) and velocity (poor <40 m/s) were measured on the deep peroneal nerve. Sensory nerve function was measured using 10- and 1.4-g monofilaments and vibration detection threshold at the toe. Lower extremity symptoms included numbness or tingling and aching or burning pain. Incident mobility disability assessed semiannually over 8.5 years (interquartile range 4.5-9.6 years) was defined as two consecutive self-reports of a lot of difficulty or inability to walk one-quarter of a mile or climb 10 steps. Nerve impairments were detected in 55% of participants, and 30% developed mobility disability. Worse motor amplitude (HR = 1.29 per SD, 95% CI = 1.16-1.44), vibration detection threshold (HR = 1.13 per SD, 95% CI = 1.04-1.23), symptoms (HR = 1.65, 95% CI = 1.26-2.17), two motor impairments (HR = 2.10, 95% CI = 1.43-3.09), two sensory impairments (HR = 1.91, 95% CI = 1.37-2.68), and three or more nerve impairments (HR = 2.33, 95% CI = 1.54-3.53) predicted incident mobility disability after adjustment. Quadriceps strength mediated relationships between certain nerve impairments and mobility disability, although most remained significant. Poor sensorimotor nerve function independently predicted mobility disability. Future work should investigate modifiable risk factors and interventions such as strength training for preventing disability and improving function in older adults with poor nerve function. © 2014, Copyright the Authors Journal compilation © 2014, The American Geriatrics Society.

The effect of vagal afferent on total vascular compliance in rats.

PubMed

Kinoshita, T

1993-04-01

This study was designed to investigate the effect of vagal afferent stimulation on total vascular compliance (TVC). Rats were anesthetized with sodium pentobarbital and artificially ventilated, TVC was determined together with stressed and unstressed blood volumes by measuring mean circulatory filling pressure (Pmcf) at three different levels of circulating blood volume. Measurements was repeated with the intact vagus, after vagotomy and during stimulation of vagal afferents. Vagotomy caused no change in TVC, Pmcf, and stressed and unstressed blood volumes. On the other hand, electrical stimulation of the vagal afferents for 30 sec increased TVC from 3.03 +/- 0.51 to 3.39 +/- 0.44 ml.mmHg(-1).kg(-1) (P < 0.05) and decreased Pmcf from 7.83 +/- 1.40 to 7.22 +/- 1.21 mmHg (P < 0.05). Neither stressed nor unstressed blood volume was changed by vagal stimulation. These results indicate that excitation of vagal afferent causes venodilation and increases TVC without changing stressed and unstressed blood volumes.

Alcohol and vagal tone as triggers for paroxysmal atrial fibrillation.

PubMed

Mandyam, Mala C; Vedantham, Vasanth; Scheinman, Melvin M; Tseng, Zian H; Badhwar, Nitish; Lee, Byron K; Lee, Randall J; Gerstenfeld, Edward P; Olgin, Jeffrey E; Marcus, Gregory M

2012-08-01

Alcohol and vagal activity may be important triggers for paroxysmal atrial fibrillation (PAF), but it remains unknown if these associations occur more often than would be expected by chance alone because of the lack of a comparator group in previous studies. We compared self-reported frequency of these triggers in patients with PAF to those with other supraventricular tachycardias (SVTs). Consecutive consenting patients presenting for electrophysiology procedures at a single university medical center underwent a structured interview regarding arrhythmia triggers. Two hundred twenty-three patients with a documented arrhythmia (133 with PAF and 90 with SVT) completed the survey. After multivariable adjustment, patients with PAF had a 4.42 greater odds (95% confidence interval [CI] 1.35 to 14.44) of reporting alcohol consumption (p = 0.014) and a 2.02 greater odds (95% CI 1.02 to 4.00) of reporting vagal activity (p = 0.044) as an arrhythmia trigger compared to patients with SVT. In patients with PAF, drinking primarily beer was associated with alcohol as a trigger (odds ratio [OR] 4.49, 95% CI 1.41 to 14.28, p = 0.011), whereas younger age (OR 0.68, 95% CI 0.49 to 0.95, p = 0.022) and a family history of AF (OR 5.73, 95% CI 1.21 to 27.23, p = 0.028) each were independently associated with having vagal activity provoke an episode. Patients with PAF and alcohol triggers were more likely to have vagal triggers (OR 10.32, 95% CI 1.05 to 101.42, p = 0.045). In conclusion, alcohol consumption and vagal activity elicit PAF significantly more often than SVT. Alcohol and vagal triggers often were found in the same patients with PAF, raising the possibility that alcohol may precipitate AF by vagal mechanisms. Copyright © 2012 Elsevier Inc. All rights reserved.

An Implantable Neuroprosthetic Device to Normalize Bladder Function after SCI

DTIC Science & Technology

2012-10-01

Billington, K.S. Tweden, R.R. Wilson, F.G. Moody, “Selection of electrical algorithms to treat obesity with intermittent vagal block using an...C.J., Tweden, K.S., Wilson, R.R., Moody, F.G. (2009). Selection of electrical algorithms to treat obesity with intermittent vagal block using an...only one cuff electrode was implanted on the left pudendal nerve. Therefore, voiding induced by intermittent stimulation was tested but pudendal

Long-term functional recovery after facial nerve transection and repair in the rat.

PubMed

Banks, Caroline A; Knox, Christopher; Hunter, Daniel A; Mackinnon, Susan E; Hohman, Marc H; Hadlock, Tessa A

2015-03-01

The rodent model is commonly used to study facial nerve injury. Because of the exceptional regenerative capacity of the rodent facial nerve, it is essential to consider the timing when studying facial nerve regeneration and functional recovery. Short-term functional recovery data following transection and repair of the facial nerve has been documented by our laboratory. However, because of the limitations of the head fixation device, there is a lack of long-term data following facial nerve injury. The objective of this study was to elucidate the long-term time course and functional deficit following facial nerve transection and repair in a rodent model. Adult rats were divided into group 1 (controls) and group 2 (experimental). Group 1 animals underwent head fixation, followed by a facial nerve injury, and functional testing was performed from day 7 to day 70. Group 2 animals underwent facial nerve injury, followed by delayed head fixation, and then underwent functional testing from months 6 to 8. There was no statistical difference between the average whisking amplitudes in group 1 and group 2 animals. Functional whisking recovery 6 months after facial nerve injury is comparable to recovery within 1 to 4 months of transection and repair, thus the ideal window for evaluating facial nerve recovery falls within the 4 months after injury. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Serotonin and cholecystokinin synergistically stimulate rat vagal primary afferent neurones

PubMed Central

Li, Y; Wu, X Y; Owyang, C

2004-01-01

Recent studies indicate that cholecystokinin (CCK) and serotonin (5-hydroxytryptamine, 5-HT) act via vagal afferent fibres to mediate gastrointestinal functions. In the present study, we characterized the interaction between CCK and 5-HT in the vagal primary afferent neurones. Single neuronal discharges of vagal primary afferent neurones innervating the duodenum were recorded from rat nodose ganglia. Two groups of nodose ganglia neurones were identified: group A neurones responded to intra-arterial injection of low doses of cholecystokinin octapeptide (CCK-8; 10–60 pmol); group B neurones responded only to high doses of CCK-8 (120–240 pmol), and were also activated by duodenal distention. CCK-JMV-180, which acts as an agonist in high-affinity states and as an antagonist in low-affinity states, dose dependently stimulated group A neurones, but inhibited the effect of the high doses of CCK-8 on group B neurones. Duodenal perfusion of 5-HT evoked dose-dependent increases in nodose neuronal discharges. Some neurones that responded to 5-HT showed no response to either high or low doses of CCK-8. A separate group of nodose neurones that possessed high-affinity CCK type A (CCK-A) receptors also responded to luminal infusion of 5-HT. Further, a subthreshold dose of CCK-8 (i.e. 5 pmol) produced no measurable electrophysiological effects but it augmented the neuronal responses to 5-HT. This potentiation effect of CCK-8 was eliminated by CR 1409. From these results we concluded that the vagal nodose ganglion contains neurones that may possess only high- or low-affinity CCK-A receptors or 5-HT3 receptors. Some neurones that express high-affinity CCK-A receptors also express 5-HT3 receptors. Pre-exposure to luminal 5-HT may augment the subsequent response to a subthreshold dose of CCK. PMID:15235095

Dual Nerve Transfers for Restoration of Shoulder Function After Brachial Plexus Avulsion Injury.

PubMed

Chu, Bin; Wang, Huan; Chen, Liang; Gu, Yudong; Hu, Shaonan

2016-06-01

The purpose of this study was to investigate the effectiveness of shoulder function restoration by dual nerve transfers, spinal accessory nerve to the suprascapular nerve and 2 intercostal nerves to the anterior branch of the axillary nerve, in patients with shoulder paralysis that resulted from brachial plexus avulsion injury. It was a retrospective analysis to assess the impact of a variety of factors on reanimation of shoulder functions with dual nerve transfers. A total of 19 patients were included in this study. Most of these patients sustained avulsions of C5, C6, and C7 nerve roots (16 patients). Three of them had avulsions of C5 and C6 roots only. Through a posterior approach, direct coaptation of the intercostal nerves and the anterior branch of the axillary nerve was performed, along with accessory nerve transfer to the suprascapular nerve. Satisfactory shoulder function recovery (93.83° of shoulder abduction and 54.00° of external rotation on average) was achieved after a 62-month follow-up. This dual nerve transfer procedure provided us with a reliable and effective method for shoulder function reconstruction after brachial plexus root avulsion, especially C5/C6/C7 avulsion. The level of evidence is therapeutic IV.

Infants' and Mothers' Vagal Reactivity in Response to Anger

ERIC Educational Resources Information Center

Moore, Ginger A.

2009-01-01

Background: Exposure to anger in the family is a risk factor for disruptive behavior disorders characterized by ineffective vagal regulation. Effects of anger on developing vagal regulation may be due to direct exposure or to effects on parents' regulation of emotion as parents support infants' regulation. Little is known about the impact of anger…

Laryngeal and tracheal afferent nerve stimulation evokes swallowing in anaesthetized guinea pigs

PubMed Central

Tsujimura, Takanori; Udemgba, Chioma; Inoue, Makoto; Canning, Brendan J

2013-01-01

We describe swallowing reflexes evoked by laryngeal and tracheal vagal afferent nerve stimulation in anaesthetized guinea pigs. The swallowing reflexes evoked by laryngeal citric acid challenges were abolished by recurrent laryngeal nerve (RLN) transection and mimicked by electrical stimulation of the central cut ends of an RLN. By contrast, the number of swallows evoked by upper airway/pharyngeal distensions was not significantly reduced by RLN transection but they were virtually abolished by superior laryngeal nerve transection. Laryngeal citric acid-evoked swallowing was mimicked by laryngeal capsaicin challenges, implicating transient receptor potential vanilloid 1 (TRPV1)-expressing laryngeal afferent nerves arising from the jugular ganglia. The swallowing evoked by citric acid and capsaicin and evoked by electrical stimulation of either the tracheal or the laryngeal mucosa occurred at stimulation intensities that were typically subthreshold for evoking cough in these animals. Swallowing evoked by airway afferent nerve stimulation also desensitized at a much slower rate than cough. We speculate that swallowing is an essential component of airway protection from aspiration associated with laryngeal and tracheal afferent nerve activation. PMID:23858010

Ventricular tachyarrhythmia-related basal cardiomyopathy in rabbits with vagal stimulation--a novel experimental model for inverted Takotsubo-like cardiomyopathy.

PubMed

Takato, Tetsuya; Ashida, Terunao; Seko, Yoshinori; Fujii, Jun; Kawai, Sachio

2010-07-01

Electrical stimulation of the intact (unsectioned) cervical vagus in rabbits frequently provokes ventricular tachyarrhythmias that are often accompanied by mitral regurgitation. Unique pathological lesions often arise on the mitral valve, papillary muscles, and mitral annulus (mitral complex), the latter two of which become swollen and stiffened. These lesions are reversible in nature. Previous studies have essentially ignored the basal portion except for the mitral annulus. Therefore, the present study examined pathological lesions on the left ventricular basal portion in rabbits. The intact right vagal nerves of 20 anesthetized rabbits were repeatedly electrically stimulated under electrocardiographic monitoring. Colloidal carbon (lml) was injected intravenously immediately after the end of the stimulation and all animals were killed 1 week later. Pathological lesions were identified as carbon deposits visible at gross examination. Ventricular bigeminy was induced after vagal stimulation in 15 (75%) of the 20 rabbits. Pathological lesions were evident on the basal portion in 16 (80%) and on the mitral valve and papillary muscles of 15 (75%) of the 20 rabbits. Ventricular bigeminy was closely associated with the development of the pathological lesions, which were rarely observed on the ventricular apex. Cardiomyopathic lesions involving the basal portion and mitral complex were frequently induced in rabbits by vagal stimulation. These lesions bear a close similarity in distribution and reversibility to inverted Takotsubo cardiomyopathy. Copyright 2010 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

High-resolution measurement of electrically-evoked vagus nerve activity in the anesthetized dog

NASA Astrophysics Data System (ADS)

Yoo, Paul B.; Lubock, Nathan B.; Hincapie, Juan G.; Ruble, Stephen B.; Hamann, Jason J.; Grill, Warren M.

2013-04-01

Objective. Not fully understanding the type of axons activated during vagus nerve stimulation (VNS) is one of several factors that limit the clinical efficacy of VNS therapies. The main goal of this study was to characterize the electrical recruitment of both myelinated and unmyelinated fibers within the cervical vagus nerve. Approach. In anesthetized dogs, recording nerve cuff electrodes were implanted on the vagus nerve following surgical excision of the epineurium. Both the vagal electroneurogram (ENG) and laryngeal muscle activity were recorded in response to stimulation of the right vagus nerve. Main results. Desheathing the nerve significantly increased the signal-to-noise ratio of the ENG by 1.2 to 9.9 dB, depending on the nerve fiber type. Repeated VNS following nerve transection or neuromuscular block (1) enabled the characterization of A-fibers, two sub-types of B-fibers, and unmyelinated C-fibers, (2) confirmed the absence of stimulation-evoked reflex compound nerve action potentials in both the ipsilateral and contralateral vagus nerves, and (3) provided evidence of stimulus spillover into muscle tissue surrounding the stimulating electrode. Significance. Given the anatomical similarities between the canine and human vagus nerves, the results of this study provide a template for better understanding the nerve fiber recruitment patterns associated with VNS therapies.

An Implantable Neuroprosthetic Device to Normalize Bladder Function after SCI

DTIC Science & Technology

2014-12-01

intermittent vagal block using an implantable medical device. Surgery for Obesity and Related Diseases 5, 224-230. 8. Frankenhaeuser B (1960...of vagal blockade to induce weight loss in morbid obesity . Obes Surg 2012;22:1771–1782. 15. Waataja JJ, Tweden KS, Honda CN. Effects of high-frequency...and Rosenblueth 1939; Rosenblueth and Reboul 1939). Recently this nerve block method has been applied to treat obesity (Camilleri et al. 2009; Wattaja

The Mid-Term Changes of Pulmonary Function Tests After Phrenic Nerve Transfer.

PubMed

Yavari, Masoud; Hassanpour, Seyed Esmail; Khodayari, Mohammad

2016-03-01

In the restoration of elbow flexion, the phrenic nerve has proven to be a good donor, but considering the role of the phrenic nerve in respiratory function, we cannot disregard the potential dangers of this method. In the current study, we reviewed the results of pulmonary function tests (PFT) in four patients who underwent phrenic nerve transfer. We reviewed the results of serial spirometry tests, which were performed before and after phrenic nerve transfer surgery. All patients regained Biceps power to M3 strength or above. None of our patients experienced pulmonary problems or respiratory complaints, but a significant reduction of spirometric parameters occurred after surgery. This study highlights the close link between the role of the phrenic nerve and pulmonary function, such that the use of this nerve as a transfer donor leads to spirometric impairments.

Slower nerve conduction velocity in individuals with functional ankle instability.

PubMed

Simon, J; Docherty, C

2014-08-01

The purpose of this study is to quantify nerve conduction velocity differences in individuals with functional ankle instability compared to a "healthy" population. 38 participants ages 18-30 were recruited from a large university with approximately 43,000 students. 19 subjects (9 men and 10 women; age=21.0±1.4 years; height=172.0±9.3 cm; mass=74.4±1 2.4 kg) with symptoms of functional ankle instability were in the functional ankle instability group. 19 subjects (10 men, 9 women; age=22.0±2.6 years; height=169.8±9.1 cm; mass=69.0±14.8 kg) with "healthy" ankles were in the control group. Nerve conduction velocity was conducted using one trial at 2 different sites: posterior to the fibular head (fibular), and 10 cm superior/posterior of the first site (popliteal). Nerve conduction velocity (m/sec) was assessed using a SierraWave II system (Cadwell Laboratories; Kennewick, WA). A MANCOVA was performed on the two dependent variables (fibular and popliteal). Covariates included surface temperature of the leg, body mass index, and age. The independent variable was group (functional ankle instability and control). The effect of group was significantly related to nerve conduction velocity at the fibular site (F(1, 27) =16.49, p=0.01) and popliteal site (F(1, 27)=4.51, p=0.01), with responses significantly faster for individuals in the control group than the functional ankle instability group. These results indicate that patients with functional ankle instability might have damage to the peroneal nerve which results in slower peroneal nerve conduction velocity. © Georg Thieme Verlag KG Stuttgart · New York.

Mechanical ventilation increases substance P concentration in the vagus, sympathetic, and phrenic nerves.

PubMed

Balzamo, E; Joanny, P; Steinberg, J G; Oliver, C; Jammes, Y

1996-01-01

Substance P (SP), a neurotransmitter localized to primary sensory neurons, is found in the vagus nerve, nodose ganglion, sympathetic chain, and phrenic nerve in various animal species. However, the changes in endogeneous SP concentration under various circumstances that involve the participation of cardiorespiratory afferent nerves are still unexplored. In the present study, attention was focused on the variations in SP content measured by radioimmunoassay (RIA) in respiratory afferent nerves (vagus nerve, cervical sympathetic chain, phrenic nerve) and respiratory muscles (diaphragm, intercostal muscles) during positive inspiratory pressure (PIP) breathing alone or PIP with an expiratory threshold load (ETL) in rabbits. SP was found in all sampled structures in spontaneously breathing control animals, prevailing in the nodose ganglion. Left-versus right-sided differences were noticed in nerves. As compared with that in control animals, the SP concentration was markedly higher in vagal and sympathetic nervous structures during PIP or PIP with ETL, and also in the phrenic nerve during ETL breathing. The SP content did not vary in respiratory muscles. These observations suggest that two very common circumstances of mechanical ventilation are associated with an increased SP concentration in nervous structures participating in the control of breathing.

Diagnosis and surgical outcomes of intraparotid facial nerve schwannoma showing normal facial nerve function.

PubMed

Lee, D W; Byeon, H K; Chung, H P; Choi, E C; Kim, S-H; Park, Y M

2013-07-01

The findings of intraparotid facial nerve schwannoma (FNS) using preoperative diagnostic tools, including ultrasonography (US)-guided fine needle aspiration biopsy, computed tomography (CT) scan, and magnetic resonance imaging (MRI), were analyzed to determine if there are any useful findings that might suggest the presence of a lesion. Treatment guidelines are suggested. The medical records of 15 patients who were diagnosed with an intraparotid FNS were retrospectively analyzed. US and CT scans provide clinicians with only limited information; gadolinium enhanced T1-weighted images from MRI provide more specific findings. Tumors could be removed successfully with surgical exploration, preserving facial nerve function at the same time. Gadolinium-enhanced T1-weighted MRI showed more characteristic findings for the diagnosis of intraparotid FNS. Intraparotid FNS without facial palsy can be diagnosed with MRI preoperatively, and surgical exploration is a suitable treatment modality which can remove the tumor and preserve facial nerve function. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Low Vagal Tone Magnifies the Association Between Psychosocial Stress Exposure and Internalizing Psychopathology in Adolescents

PubMed Central

McLaughlin, Katie A.; Rith-Najarian, Leslie; Dirks, Melanie A.; Sheridan, Margaret A.

2014-01-01

Vagal tone is a measure of cardiovascular function that facilitates adaptive responses to environmental challenge. Low vagal tone is associated with poor emotional and attentional regulation in children and has been conceptualized as a marker of sensitivity to stress. We investigated whether the associations of a wide range of psychosocial stressors with internalizing and externalizing psychopathology were magnified in adolescents with low vagal tone. Resting heart period data were collected from a diverse community sample of adolescents (ages 13–17; N =168). Adolescents completed measures assessing internalizing and externalizing psychopathology and exposure to stressors occurring in family, peer, and community contexts. Respiratory sinus arrhythmia (RSA) was calculated from the interbeat interval time series. We estimated interactions between RSA and stress exposure in predicting internalizing and externalizing symptoms and evaluated whether interactions differed by gender. Exposure to psychosocial stressors was associated strongly with psychopathology. RSA was unrelated to internalizing or externalizing problems. Significant interactions were observed between RSA and child abuse, community violence, peer victimization, and traumatic events in predicting internalizing but not externalizing symptoms. Stressors were positively associated with internalizing symptoms in adolescents with low RSA but not in those with high RSA. Similar patterns were observed for anxiety and depression. These interactions were more consistently observed for male than female individuals. Low vagal tone is associated with internalizing psychopathology in adolescents exposed to high levels of stressors. Measurement of vagal tone in clinical settings might provide useful information about sensitivity to stress in child and adolescent clients. PMID:24156380

Learning by heart-the relationship between resting vagal tone and metacognitive judgments: a pilot study.

PubMed

Meessen, Judith; Sütterlin, Stefan; Gauggel, Siegfried; Forkmann, Thomas

2018-05-23

Metacognitive awareness and resting vagally mediated heart rate variability (HRV) as a physiological trait marker of cognitive inhibitory control capacities are both associated with better well-being and seem to share a common neural basis. Executive functioning which is considered a prerequisite for delivering prospective metacognitive judgments has been found to be correlated with HRV. This pilot study addresses the question, whether metacognitive awareness and resting vagally mediated HRV are positively associated. A sample of 20 healthy participants was analyzed that completed a typical Judgment of Learning task after an electrocardiogram had been recorded. The root-mean-squares of successive differences were used to calculate vagally mediated HRV. Metacognitive awareness was measured by comparing the judgments of learning with the actual memory performance, yielding a deviation score. HRV was found to be positively correlated with metacognitive awareness. Results suggest that metacognitive abilities might relate to physiological trait markers of cognitive inhibitory control capacities. Further experimental studies are needed to investigate causal relations.

A Transactional Analysis of the Relation between Maternal Sensitivity and Child Vagal Regulation

ERIC Educational Resources Information Center

Perry, Nicole B.; Mackler, Jennifer S.; Calkins, Susan D.; Keane, Susan P.

2014-01-01

A transactional model examining the longitudinal association between vagal regulation (as indexed by vagal withdrawal) and maternal sensitivity from age 2.5 to age 5.5 was assessed. The sample included 356 children (171 male, 185 female) and their mothers who participated in a laboratory visit at age 2.5, 4.5, and 5.5. Cardiac vagal tone was…

Electrophysiologic alterations in the excitability of the sciatic and vagus nerves during early stages of sepsis.

PubMed

Diniz, Lúcio Ricardo Leite; Portella, Viviane Gomes; da Silva Alves, Kerly Shamira; Araújo, Pâmella Cristina da Costa; de Albuquerque Júnior, Ricardo Luiz Cavalcanti; Cavalcante de Albuquerque, Aline Alice; Coelho-de-Souza, Andrelina Noronha; Leal-Cardoso, José Henrique

2018-01-01

Nonspecific and delayed diagnosis of neurologic damage contributes to the development of neuropathies in patients with severe sepsis. The present study assessed the electrophysiologic parameters related to the excitability and conductibility of sciatic and vagus nerves during early stages of sepsis. Twenty-four hours after sepsis induced by cecal ligation and puncture (CLP) model, sciatic and vagus nerves of septic (CLP group) and control (sham group) rats were removed, and selected electric stimulations were applied to measure the parameters of the first and second components of the compound action potential. The first component originated from fibers with motor and sensory functions (Types A α and A β fibers) with a large conduction velocity (70-120 m/s), and the second component originated from fibers (Type A γ ) with sensorial function. To evaluate the presence of sensorial alterations, the sensitivity to non-noxious mechanical stimuli was measured by using the von Frey test. Hematoxylin and eosin staining of the nerves was performed. We observed an increase of rheobase followed by a decrease in the first component amplitude and a higher paw withdrawal threshold in response to the application of von Frey filaments in sciatic nerves from the CLP group compared to the sham group. Differently, a decrease in rheobase and an increase in the first component amplitude of vagal C fibers from CLP group were registered. No significant morphologic alteration was observed. Our data showed that the electrophysiologic alterations in peripheral nerves vary with the fiber type and might be identified in the first 24 h of sepsis, before clinical signs of neuromuscular disorders.

Low-Level Laser Irradiation Improves Functional Recovery and Nerve Regeneration in Sciatic Nerve Crush Rat Injury Model

PubMed Central

Wang, Chau-Zen; Chen, Yi-Jen; Wang, Yan-Hsiung; Yeh, Ming-Long; Huang, Mao-Hsiung; Ho, Mei-Ling; Liang, Jen-I; Chen, Chia-Hsin

2014-01-01

The development of noninvasive approaches to facilitate the regeneration of post-traumatic nerve injury is important for clinical rehabilitation. In this study, we investigated the effective dose of noninvasive 808-nm low-level laser therapy (LLLT) on sciatic nerve crush rat injury model. Thirty-six male Sprague Dawley rats were divided into 6 experimental groups: a normal group with or without 808-nm LLLT at 8 J/cm2 and a sciatic nerve crush injury group with or without 808-nm LLLT at 3, 8 or 15 J/cm2. Rats were given consecutive transcutaneous LLLT at the crush site and sacrificed 20 days after the crush injury. Functional assessments of nerve regeneration were analyzed using the sciatic functional index (SFI) and hindlimb range of motion (ROM). Nerve regeneration was investigated by measuring the myelin sheath thickness of the sciatic nerve using transmission electron microscopy (TEM) and by analyzing the expression of growth-associated protein 43 (GAP43) in sciatic nerve using western blot and immunofluorescence staining. We found that sciatic-injured rats that were irradiated with LLLT at both 3 and 8 J/cm2 had significantly improved SFI but that a significant improvement of ROM was only found in rats with LLLT at 8 J/cm2. Furthermore, the myelin sheath thickness and GAP43 expression levels were significantly enhanced in sciatic nerve-crushed rats receiving 808-nm LLLT at 3 and 8 J/cm2. Taken together, these results suggest that 808-nm LLLT at a low energy density (3 J/cm2 and 8 J/cm2) is capable of enhancing sciatic nerve regeneration following a crush injury. PMID:25119457

Nerve Transfers for Improved Hand Function Following Cervical Spinal Cord Injury

DTIC Science & Technology

the cervical spine resulting in diminished or complete loss of arm and/or hand function. Cervical SCI patients consistently rank hand function as the...most desired function above bowel and bladder function, sexual function, standing, and pain control. The overall goal of the proposed study is to...evaluate the efficacy of nerve transfers to treat patients with cervical SCIs. Over the last decade, nerve transfers have been used with increasing

Functional characterization of optimized acellular peripheral nerve graft in a rat sciatic nerve injury model.

PubMed

Nagao, Ryan J; Lundy, Scott; Khaing, Zin Z; Schmidt, Christine E

2011-07-01

Acellular grafts are a viable option for use in nerve reconstruction surgeries. Recently, our lab created a novel optimized decellularization procedure that removes immunological material while leaving the majority of the extracellular matrix structure intact. The optimized acellular (OA) graft has been shown to elicit an immune response equal to or less than that elicited by the isograft, the analog of the autograft in the rat model. We investigated the performance of the OA graft to provide functional recovery in a long-term study. We performed a long-term functional regeneration evaluation study using the sciatic functional index to quantify recovery of Lewis rats at regular time intervals for up to 52 weeks after graft implantation following 1 cm sciatic nerve resection. OA grafts were compared against other decellularized methods (Sondell treatment and thermal decellularization), as well as the isograft and primary neurorrhaphy. The OA graft supported comparable functional recovery to the isograft and superior regeneration to thermal and Sondell decellularization methods. Furthermore, the OA graft promoted early recovery to a greater degree compared to acellular grafts obtained using either the thermal or the Sondell methods. Equivalent functional recovery to the isograft suggests that the OA nerve graft may be a future clinical alternative to the current autologous tissue graft.

FOOD-INTAKE DYSREGULATION IN TYPE 2 DIABETIC GOTO-KAKIZAKI RATS: HYPOTHESIZED ROLE OF DYSFUNCTIONAL BRAINSTEM THYROTROPIN-RELEASING HORMONE AND IMPAIRED VAGAL OUTPUT

PubMed Central

Zhao, K.; Ao, Y.; Harper, R.M.; Go, V. L.W.; Yang, H.

2013-01-01

Thyrotropin-releasing hormone (TRH), a neuropeptide contained in neural terminals innervating brainstem vagal motor neurons, enhances vagal outflow to modify multisystemic visceral functions and food intake. Type 2 diabetes (T2D) and obesity are accompanied by impaired vagal functioning. We examined the possibility that impaired brainstem TRH action may contribute to the vagal dysregulation of food intake in Goto-Kakizaki (GK) rats, a T2D model with hyperglycemia and impaired central vagal activation by TRH. Food intake induced by intracisternal injection of TRH analog was reduced significantly by 50% in GK rats, compared to Wistar rats. Similarly, natural food intake in the dark phase or food intake after an overnight fast was reduced by 56–81% in GK rats. Fasting (48 h) and refeeding (2 h)-associated changes in serum ghrelin, insulin, peptide YY, pancreatic polypeptide and leptin, and the concomitant changes in orexigenic or anorexigenic peptide expression in the brainstem and hypothalamus, all apparent in Wistar rats, were absent or markedly reduced in GK rats, with hormone release stimulated by vagal activation, such as ghrelin and pancreatic polypeptide, decreased substantially. Fasting-induced Fos expression accompanying endogenous brainstem TRH action decreased by 66% and 91%, respectively, in the nucleus tractus solitarius (NTS) and the dorsal motor nucleus of the vagus (DMV) in GK rats, compared to Wistar rats. Refeeding abolished fasting-induced Fos-expression in the NTS, while that in the DMV remained in Wistar but not GK rats. These findings indicate that dysfunctional brainstem TRH-elicited vagal impairment contributes to the disturbed food intake in T2D GK rats, and may provide a pathophysiological mechanism which prevents further weight gain in T2D and obesity. PMID:23701881

Food-intake dysregulation in type 2 diabetic Goto-Kakizaki rats: hypothesized role of dysfunctional brainstem thyrotropin-releasing hormone and impaired vagal output.

PubMed

Zhao, K; Ao, Y; Harper, R M; Go, V L W; Yang, H

2013-09-05

Thyrotropin-releasing hormone (TRH), a neuropeptide contained in neural terminals innervating brainstem vagal motor neurons, enhances vagal outflow to modify multisystemic visceral functions and food intake. Type 2 diabetes (T2D) and obesity are accompanied by impaired vagal functioning. We examined the possibility that impaired brainstem TRH action may contribute to the vagal dysregulation of food intake in Goto-Kakizaki (GK) rats, a T2D model with hyperglycemia and impaired central vagal activation by TRH. Food intake induced by intracisternal injection of TRH analog was reduced significantly by 50% in GK rats, compared to Wistar rats. Similarly, natural food intake in the dark phase or food intake after an overnight fast was reduced by 56-81% in GK rats. Fasting (48h) and refeeding (2h)-associated changes in serum ghrelin, insulin, peptide YY, pancreatic polypeptide and leptin, and the concomitant changes in orexigenic or anorexigenic peptide expression in the brainstem and hypothalamus, all apparent in Wistar rats, were absent or markedly reduced in GK rats, with hormone release stimulated by vagal activation, such as ghrelin and pancreatic polypeptide, decreased substantially. Fasting-induced Fos expression accompanying endogenous brainstem TRH action decreased by 66% and 91%, respectively, in the nucleus tractus solitarius (NTS) and the dorsal motor nucleus of the vagus (DMV) in GK rats, compared to Wistar rats. Refeeding abolished fasting-induced Fos-expression in the NTS, while that in the DMV remained in Wistar but not GK rats. These findings indicate that dysfunctional brainstem TRH-elicited vagal impairment contributes to the disturbed food intake in T2D GK rats, and may provide a pathophysiological mechanism which prevents further weight gain in T2D and obesity. Published by Elsevier Ltd.

Lymphocyte responses to stress in postpartum women: relationship to vagal tone.

PubMed

Redwine, L S; Altemus, M; Leong, Y M; Carter, C S

2001-04-01

Although women spend their lives in various phases of the reproductive cycle, including menstrual, pregnancy, postpartum, lactation and menopause, few studies have examined immune responses to stress in women as a function of events associated with reproduction. The objective of this study was to evaluate differential effects of breastfeeding (n = 16), bottlefeeding (n = 10) and non-postpartum (n = 10) status on lymphocyte responses to stressful tasks (public speaking and mental arithmetic). To measure cellular immune responses, lymphocyte proliferation to plant lectins, poke weed mitogen (PWM) and phytohemagglutinin (PHA) were used. The autonomic measures, heart rate, vagal tone, blood pressure and the hormones of the HPA axis, ACTH and cortisol, were measured and their possible roles in mediating lymphocyte proliferation responses were examined. Recently parturient women who were breastfeeding or bottlefeeding had attenuated stress-induced change in lymphocyte responses to PWM compared with non-postpartum women, tested in the follicular phase of their cycle (P < 0.05). Also, lymphocyte responses to PHA were higher in the breastfeeding group compared with non-postpartum controls (P < 0.05). Regression analyses revealed that an index of cardiac vagal tone, but not other autonomic or endocrine measures, was positively predictive of lymphocyte proliferation to PWM. To summarize, these findings suggest that lactation and parturition can influence lymphocyte proliferation and that activity in the vagal system may influence lymphocyte responses to stress.

[Changes in facial nerve function, morphology and neurotrophic factor III expression following three types of facial nerve injury].

PubMed

Zhang, Lili; Wang, Haibo; Fan, Zhaomin; Han, Yuechen; Xu, Lei; Zhang, Haiyan

2011-01-01

To study the changes in facial nerve function, morphology and neurotrophic factor III (NT-3) expression following three types of facial nerve injury. Changes in facial nerve function (in terms of blink reflex (BF), vibrissae movement (VM) and position of nasal tip) were assessed in 45 rats in response to three types of facial nerve injury: partial section of the extratemporal segment (group one), partial section of the facial canal segment (group two) and complete transection of the facial canal segment lesion (group three). All facial nerves specimen were then cut into two parts at the site of the lesion after being taken from the lesion site on 1st, 7th, 21st post-surgery-days (PSD). Changes of morphology and NT-3 expression were evaluated using the improved trichrome stain and immunohistochemistry techniques ,respectively. Changes in facial nerve function: In group 1, all animals had no blink reflex (BF) and weak vibrissae movement (VM) at the 1st PSD; The blink reflex in 80% of the rats recovered partly and the vibrissae movement in 40% of the rats returned to normal at the 7th PSD; The facial nerve function in 600 of the rats was almost normal at the 21st PSD. In group 2, all left facial nerve paralyzed at the 1st PSD; The blink reflex partly recovered in 40% of the rats and the vibrissae movement was weak in 80% of the rats at the 7th PSD; 8000 of the rats'BF were almost normal and 40% of the rats' VM completely recovered at the 21st PSD. In group 3, The recovery couldn't happen at anytime. Changes in morphology: In group 1, the size of nerve fiber differed in facial canal segment and some of myelin sheath and axons degenerated at the 7th PSD; The fibres' degeneration turned into regeneration at the 21st PSD; In group 2, the morphologic changes in this group were familiar with the group 1 while the degenerated fibers were more and dispersed in transection at the 7th PSD; Regeneration of nerve fibers happened at the 21st PSD. In group 3, most of the fibers

Tachycardia, reduced vagal capacity, and age-dependent ventricular dysfunction arising from diminished expression of the presynaptic choline transporter.

PubMed

English, Brett A; Appalsamy, Martin; Diedrich, Andre; Ruggiero, Alicia M; Lund, David; Wright, Jane; Keller, Nancy R; Louderback, Katherine M; Robertson, David; Blakely, Randy D

2010-09-01

Healthy cardiovascular function relies on a balanced and responsive integration of noradrenergic and cholinergic innervation of the heart. High-affinity choline uptake by cholinergic terminals is pivotal for efficient ACh production and release. To date, the cardiovascular impact of diminished choline transporter (CHT) expression has not been directly examined, largely due to the transporter's inaccessibility in vivo. Here, we describe findings from cardiovascular experiments using transgenic mice that bear a CHT genetic deficiency. Whereas CHT knockout (CHT(-/-)) mice exhibit early postnatal lethality, CHT heterozygous (CHT(+/-)) mice survive, grow, and reproduce normally and exhibit normal spontaneous behaviors. However, the CHT(+/-) mouse heart displays significantly reduced levels of high-affinity choline uptake accompanied by significantly reduced levels of ACh. Telemeterized recordings of cardiovascular function in these mice revealed tachycardia and hypertension at rest. After treadmill exercise, CHT(+/-) mice exhibited slower heart rate recovery, consistent with a diminished cholinergic reserve, a contention validated through direct vagal nerve stimulation. Echocardiographic and histological experiments revealed an age-dependent decrease in fractional shortening, increased left ventricular dimensions, and increased ventricular fibrosis, consistent with ventricular dysfunction. These cardiovascular phenotypes of CHT(+/-) mice encourage an evaluation of humans bearing reduced CHT expression for their resiliency in maintaining proper heart function as well as risk for cardiovascular disease.

Neurotransmission to parasympathetic cardiac vagal neurons in the brain stem is altered with left ventricular hypertrophy-induced heart failure.

PubMed

Cauley, Edmund; Wang, Xin; Dyavanapalli, Jhansi; Sun, Ke; Garrott, Kara; Kuzmiak-Glancy, Sarah; Kay, Matthew W; Mendelowitz, David

2015-10-01

Hypertension, cardiac hypertrophy, and heart failure (HF) are widespread and debilitating cardiovascular diseases that affect nearly 23 million people worldwide. A distinctive hallmark of these cardiovascular diseases is autonomic imbalance, with increased sympathetic activity and decreased parasympathetic vagal tone. Recent device-based approaches, such as implantable vagal stimulators that stimulate a multitude of visceral sensory and motor fibers in the vagus nerve, are being evaluated as new therapeutic approaches for these and other diseases. However, little is known about how parasympathetic activity to the heart is altered with these diseases, and this lack of knowledge is an obstacle in the goal of devising selective interventions that can target and selectively restore parasympathetic activity to the heart. To identify the changes that occur within the brain stem to diminish the parasympathetic cardiac activity, left ventricular hypertrophy was elicited in rats by aortic pressure overload using a transaortic constriction approach. Cardiac vagal neurons (CVNs) in the brain stem that generate parasympathetic activity to the heart were identified with a retrograde tracer and studied using patch-clamp electrophysiological recordings in vitro. Animals with left cardiac hypertrophy had diminished excitation of CVNs, which was mediated both by an augmented frequency of spontaneous inhibitory GABAergic neurotransmission (with no alteration of inhibitory glycinergic activity) as well as a diminished amplitude and frequency of excitatory neurotransmission to CVNs. Opportunities to alter these network pathways and neurotransmitter receptors provide future targets of intervention in the goal to restore parasympathetic activity and autonomic balance to the heart in cardiac hypertrophy and other cardiovascular diseases. Copyright © 2015 the American Physiological Society.

Influencing Factors Analysis of Facial Nerve Function after the Microsurgical Resection of Acoustic Neuroma

PubMed Central

Hong, WenMing; Cheng, HongWei; Wang, XiaoJie; Feng, ChunGuo

2017-01-01

Objective To explore and analyze the influencing factors of facial nerve function retainment after microsurgery resection of acoustic neurinoma. Methods Retrospective analysis of our hospital 105 acoustic neuroma cases from October, 2006 to January 2012, in the group all patients were treated with suboccipital sigmoid sinus approach to acoustic neuroma microsurgery resection. We adopted researching individual patient data, outpatient review and telephone followed up and the House-Brackmann grading system to evaluate and analyze the facial nerve function. Results Among 105 patients in this study group, complete surgical resection rate was 80.9% (85/105), subtotal resection rate was 14.3% (15/105), and partial resection rate 4.8% (5/105). The rate of facial nerve retainment on neuroanatomy was 95.3% (100/105) and the mortality rate was 2.1% (2/105). Facial nerve function when the patient is discharged from the hospital, also known as immediate facial nerve function which was graded in House-Brackmann: excellent facial nerve function (House-Brackmann I–II level) cases accounted for 75.2% (79/105), facial nerve function III–IV level cases accounted for 22.9% (24/105), and V–VI cases accounted for 1.9% (2/105). Patients were followed up for more than one year, with excellent facial nerve function retention rate (H-B I–II level) was 74.4% (58/78). Conclusion Acoustic neuroma patients after surgery, the long-term (≥1 year) facial nerve function excellent retaining rate was closely related with surgical proficiency, post-operative immediate facial nerve function, diameter of tumor and whether to use electrophysiological monitoring techniques; while there was no significant correlation with the patient’s age, surgical approach, whether to stripping the internal auditory canal, whether there was cystic degeneration, tumor recurrence, whether to merge with obstructive hydrocephalus and the length of the duration of symptoms. PMID:28264236

Auricular vagal nerve stimulation in peripheral arterial disease patients.

PubMed

Hackl, Gerald; Prenner, Andreas; Jud, Philipp; Hafner, Franz; Rief, Peter; Seinost, Gerald; Pilger, Ernst; Brodmann, Marianne

2017-10-01

Auricular nerve stimulation has been proven effective in different diseases. We investigated if a conservative therapeutic alternative for claudication in peripheral arterial occlusive disease (PAD) via electroacupuncture of the outer ear can be established. In this prospective, double-blinded trial an ear acupuncture using an electroacupuncture device was carried out in 40 PAD patients in Fontaine stage IIb. Twenty patients were randomized to the verum group using a fully functional electroacupuncture device, the other 20 patients received a sham device (control group). Per patient, eight cycles (1 cycle = 1 week) of electroacupuncture were performed. The primary endpoint was defined as a significantly more frequent doubling of the absolute walking distance after eight cycles in the verum group compared to controls in a standardized treadmill testing. Secondary endpoints were a significant improvement of the total score of the Walking Impairment Questionnaire (WIQ) as well as improvements in health related quality of life using the Short Form 36 Health Survey (SF-36). There were no differences in baseline characteristics between the two groups. The initial walking distance significantly increased in both groups (verum group [means]: 182 [95 % CI 128-236] meters to 345 [95 % CI 227-463] meters [+ 90 %], p < 0.01; control group [means]: 159 [95 % CI 109-210] meters to 268 [95 % CI 182-366] meters [+ 69 %], p = 0.01). Twelve patients (60 %) in the verum group and five patients (25 %) in controls reached the primary endpoint of doubling walking distance (p = 0.05). The total score of WIQ significantly improved in the verum group (+ 22 %, p = 0.01) but not in controls (+ 8 %, p = 0.56). SF-36 showed significantly improvements in six out of eight categories in the verum group and only in one of eight in controls. Electroacupuncture of the outer ear seems to be an easy-to-use therapeutic option in an age of increasingly invasive and mechanically complex treatments for

Preservation of Facial Nerve Function Repaired by Using Fibrin Glue-Coated Collagen Fleece for a Totally Transected Facial Nerve during Vestibular Schwannoma Surgery

PubMed Central

Choi, Kyung-Sik; Kim, Min-Su; Jang, Sung-Ho

2014-01-01

Recently, the increasing rates of facial nerve preservation after vestibular schwannoma (VS) surgery have been achieved. However, the management of a partially or completely damaged facial nerve remains an important issue. The authors report a patient who was had a good recovery after a facial nerve reconstruction using fibrin glue-coated collagen fleece for a totally transected facial nerve during VS surgery. And, we verifed the anatomical preservation and functional outcome of the facial nerve with postoperative diffusion tensor (DT) imaging facial nerve tractography, electroneurography (ENoG) and House-Brackmann (HB) grade. DT imaging tractography at the 3rd postoperative day revealed preservation of facial nerve. And facial nerve degeneration ratio was 94.1% at 7th postoperative day ENoG. At postoperative 3 months and 1 year follow-up examination with DT imaging facial nerve tractography and ENoG, good results for facial nerve function were observed. PMID:25024825

Recovery of laryngeal function after intraoperative injury to the recurrent laryngeal nerve

PubMed Central

Hydman, Jonas; Svensson, Mikael

2015-01-01

Loss of function in the recurrent laryngeal nerve (RLN) during thyroid/parathyroid surgery, despite a macroscopically intact nerve, is a challenge which highlights the sensitivity and complexity of laryngeal innervation. Furthermore, the uncertain prognosis stresses a lack of capability to diagnose the reason behind the impaired function. There is a great deal of literature considering risk factors, surgical technique and mechanisms outside the nerve affecting the incidence of RLN paresis during surgery. To be able to prognosticate recovery in cases of laryngeal dysfunction and voice changes after thyroid surgery, the surgeon would first need to define the presence, location, and type of laryngeal nerve injury. There is little data describing the events within the nerve and the neurobiological reasons for the impaired function related to potential recovery and prognosis. In addition, very little data has been presented in order to clarify any differences between the transient and permanent injury of the RLN. This review aims, from an anatomical and neurobiological perspective, to provide an update on the current understandings of surgically-induced injury to the laryngeal nerves. PMID:25713777

Longitudinal relations between child vagal tone and parenting behavior: 2 to 4 years.

PubMed

Kennedy, Amy E; Rubin, Kenneth H; Hastings, Paul D; Maisel, Beth

2004-07-01

The longitudinal relations between physiological markers of child emotion regulation and maternal parenting practices were examined from 2 to 4 years of age. At Time 1, cardiac vagal tone was assessed for one hundred four 2-year-olds (54 females); their mothers completed an assessment of parenting styles. Two years later, at Time 2, 84 of the original participants were reassessed on measures of cardiac vagal tone and parenting style. Results indicated both baseline cardiac vagal tone and maternal parenting practices to be stable from 2 to 4 years of age. Children's cardiac vagal tone predicted specific parenting practices from the toddler to preschool years. Further, child cardiac vagal tone moderated maternal restrictive-parenting practices from 2 to 4 years of age; mothers of children who were highly or moderately physiologically dysregulated were more likely to report restrictive parenting practices at both 2 and 4 years of age. Copyright 2004 Wiley Periodicals, Inc.

Lower Cardiac Vagal Tone in Non-Obese Healthy Men with Unfavorable Anthropometric Characteristics

PubMed Central

Ramos, Plínio S.; Araújo, Claudio Gil S.

2010-01-01

OBJECTIVES: to determine if there are differences in cardiac vagal tone values in non-obese healthy, adult men with and without unfavorable anthropometric characteristics. INTRODUCTION: It is well established that obesity reduces cardiac vagal tone. However, it remains unknown if decreases in cardiac vagal tone can be observed early in non-obese healthy, adult men presenting unfavorable anthropometric characteristics. METHODS: Among 1688 individuals assessed between 2004 and 2008, we selected 118 non-obese (BMI <30 kg/m2), healthy men (no known disease conditions or regular use of relevant medications), aged between 20 and 77 years old (42 ± 12-years-old). Their evaluation included clinical examination, anthropometric assessment (body height and weight, sum of six skinfolds, waist circumference and somatotype), a 4-second exercise test to estimate cardiac vagal tone and a maximal cardiopulmonary exercise test to exclude individuals with myocardial ischemia. The same physician performed all procedures. RESULTS: A lower cardiac vagal tone was found for the individuals in the higher quintiles – unfavorable anthropometric characteristics - of BMI (p=0.005), sum of six skinfolds (p=0.037) and waist circumference (p<0.001). In addition, the more endomorphic individuals also presented a lower cardiac vagal tone (p=0.023), while an ectomorphic build was related to higher cardiac vagal tone values as estimated by the 4-second exercise test (r=0.23; p=0.017). CONCLUSIONS: Non-obese and healthy adult men with unfavorable anthropometric characteristics tend to present lower cardiac vagal tone levels. Early identification of this trend by simple protocols that are non-invasive and risk-free, using select anthropometric characteristics, may be clinically useful in a global strategy to prevent cardiovascular disease. PMID:20126345

The central nucleus of the amygdala modulates gut-related neurons in the dorsal vagal complex in rats

PubMed Central

Zhang, Xueguo; Cui, Jinjuan; Tan, Zhenjun; Jiang, Chunhui; Fogel, Ronald

2003-01-01

Using retrograde tract-tracing and electrophysiological methods, we characterized the anatomical and functional relationship between the central nucleus of the amygdala and the dorsal vagal complex. Retrograde tract-tracing techniques revealed that the central nucleus of the amygdala projects to the dorsal vagal complex with a topographic distribution. Following injection of retrograde tracer into the vagal complex, retrogradely labelled neurons in the central nucleus of the amygdala were clustered in the central portion at the rostral level and in the medial part at the middle level of the nucleus. Few labelled neurons were seen at the caudal level. Electrical stimulation of the central nucleus of the amygdala altered the basal firing rates of 65 % of gut-related neurons in the nucleus of the solitary tract and in the dorsal motor nucleus of the vagus. Eighty-one percent of the neurons in the nucleus of the solitary tract and 47 % of the neurons in the dorsal motor nucleus were inhibited. Electrical stimulation of the central nucleus of the amygdala also modulated the response of neurons in the dorsal vagal complex to gastrointestinal stimuli. The predominant effect on the neurons of the nucleus of the solitary tract was inhibition. These results suggest that the central nucleus of the amygdala influences gut-related neurons in the dorsal vagal complex and provides a neuronal circuitry that explains the regulation of gastrointestinal activity by the amygdala. PMID:14555729

IN VITRO RESEARCH OF THE ALTERATION OF NEURONS IN VAGAL CORE IN MEDULLA OBLONGATA AT ASPHYXIC DEATHS

PubMed Central

Haliti, Naim; Islami, Hilmi; Elezi, Nevzat; Shabani, Ragip; Abdullahu, Bedri; Dragusha, Gani

2010-01-01

The aim of this study was to research the morphological changes of neurons in the vagus nerve nuclei in medulla oblongata in asphyxia related death cases. Morphological changes that were investigated were mainly in the dorsal motor respiratory center (DMRC), nucleus tractus solitarius (nTS) and nucleus ambigus (nA) in the medulla oblongata. In our research, the autopsy material from asphyxia related death cases was used from various etiologies: monoxide carbon (CO), liquid drowning, strangulation, electricity, clinical-pathological death, firing weapon, explosive weapon, sharp and blunt objects and death cases due to accident. The material selected for research was taken from medulla oblongata and lungs from all lobes. The material from the medulla oblongata and lungs was fixed in a 10% solution of buffered formalin. Special histochemical methods for central nervous system (CNS) were employed like: Cresyl echt violet, toluidin blue, Sevier-Munger modification and Grimelius. For stereometrical analysis of the quantitative density of the neurons the universal testing system Weibel M42 was used. The acquired results show that in sudden asphyxia related death cases, there are alterations in the nuclei of vagal nerve in form of: central chromatolysis, axonal retraction, axonal fragmentation, intranuclear vacuolization, cytoplasmic vacuolization, edema, condensation and dispersion of substance of Nissl, proliferation of oligodendrocytes, astrocytes and microglia. The altered population of vagus nerve neurons does not show an important statistica! significarne compared to the overall quantity of the neurons in the nuclei of the vagus nerve (p<0,05). PMID:20846134

Placebo-controlled vagus nerve stimulation paired with tones in a patient with refractory tinnitus: a case report.

PubMed

De Ridder, Dirk; Kilgard, Michael; Engineer, Navzer; Vanneste, Sven

2015-04-01

Classical neuromodulation consists of applying electrical or magnetic stimuli to the nervous system to modulate ongoing activity and connectivity. However, recently, an exciting novel neuromodulation technique was developed in which stimulation of the vagal nerve was paired with simultaneous presentation of tones, demonstrating that it reverses a tinnitus percept in noise-exposed rats. To determine whether this therapy could also be effective in humans, we delivered a similar therapy in a patient with chronic tinnitus unresponsive to previous therapies. In this report, we describe the case of a 59-year-old man who suffered from bilateral tinnitus for 14 years that arose after a cervical fusion operation. Pharmacotherapy, transcranial magnetic stimulation, transcranial direct current stimulation, neurofeedback, and bilateral auditory cortex stimulation via implanted electrodes did not improve the tinnitus. After implanting the vagal nerve stimulator, the patient received daily vagus nerve stimulation tone pairings for 4 weeks in a non-placebo-controlled way. At the end of therapy, the patient experienced a significant reduction in tinnitus symptoms that lasted for 2 months after treatment. Tinnitus Handicap Inventory and Tinnitus Reaction Questionnaire were reduced by 48% and 68%, respectively. Symptoms of depression were also improved by 40%, as quantified by the Beck Depression Inventory. Three months after ending therapy, placebo stimulation was performed consisting of only tone presentation without the simultaneous electrical stimuli. This resulted in further continuation of the gradual relapse to the baseline state, without renewed improvement. Our results suggest that vagus nerve stimulation paired with tones could become an effective therapy for the treatment of tinnitus.

Electrical stimulation accelerates motor functional recovery in autograft-repaired 10 mm femoral nerve gap in rats.

PubMed

Huang, Jinghui; Hu, Xueyu; Lu, Lei; Ye, Zhengxu; Wang, Yuqing; Luo, Zhuojing

2009-10-01

Electrical stimulation has been shown to enhance peripheral nerve regeneration after nerve injury. However, the impact of electrical stimulation on motor functional recovery after nerve injuries, especially over long nerve gap lesions, has not been investigated in a comprehensive manner. In the present study, we aimed to determine whether electrical stimulation (1 h, 20 Hz) is beneficial for motor functional recovery after a 10 mm femoral nerve gap lesion in rats. The proximal nerve stump was electrically stimulated for 1 h at 20 Hz frequency prior to nerve repair with an autologous graft. The rate of motor functional recovery was evaluated by single frame motion analysis and electrophysiological studies, and the nerve regeneration was investigated by double labeling and histological analysis. We found that brief electrical stimulation significantly accelerated motor functional recovery and nerve regeneration. Although the final outcome, both in functional terms and morphological terms, was not improved by electrical stimulation, the observed acceleration of functional recovery and axon regeneration may be of therapeutic importance in clinical setting.

Vagal Afferent Innervation of the Lower Esophageal Sphincter

PubMed Central

Powley, Terry L.; Baronowsky, Elizabeth A.; Gilbert, Jared M.; Hudson, Cherie N.; Martin, Felecia N.; Mason, Jacqueline K.; McAdams, Jennifer L.; Phillips, Robert J.

2013-01-01

To supply a fuller morphological characterization of the vagal afferents innervating the lower esophageal sphincter (LES), specifically to label vagal terminals in the tissues forming the LES in the gastroesophageal junction, the present experiment employed injections of dextran biotin into the nodose ganglia of rats. Four types of vagal afferents innervated the LES. Clasp and sling muscle fibers were directly and prominently innervated by intramuscular arrays (IMAs). Individual IMA terminals subtended about 16° of arc of the esophageal circumference, and, collectively, the terminal fields were distributed within the muscle ring to establish a 360° annulus of mechanoreceptors in the sphincter wall. 3D morphometry of the terminals established that, compared to sling muscle IMAs, clasp muscle IMAs had more extensive arbors and larger receptive fields. In addition, at the cardia, local myenteric ganglia between smooth muscle sheets and striated muscle bundles were innervated by intraganglionic laminar endings (IGLEs), in a pattern similar to the innervation of the myenteric plexus throughout the stomach and esophagus. Finally, as previously described, the principle bundle of sling muscle fibers that links LES sphincter tissue to the antropyloric region of the lesser curvature was innervated by exceptionally long IMAs as well as by unique web ending specializations at the distal attachment of the bundle. Overall, the specialized varieties of densely distributed vagal afferents innervating the LES underscore the conclusion that these sensory projections are critically involved in generating LES reflexes and may be promising targets for managing esophageal dysfunctions. PMID:23583280

Innervation of the human cricopharyngeal muscle by the recurrent laryngeal nerve and external branch of the superior laryngeal nerve.

PubMed

Uludag, Mehmet; Aygun, Nurcihan; Isgor, Adnan

2017-06-01

The major component of the upper esophageal sphincter is the cricopharyngeal muscle (CPM). We assessed the contribution of the laryngeal nerves to motor innervation of the CPM. We performed an intraoperative electromyographic study of 27 patients. The recurrent laryngeal nerve (RLN), vagus nerve, external branch of the superior laryngeal nerve (EBSLN), and pharyngeal plexus (PP) were stimulated. Responses were evaluated by visual observation of CPM contractions and electromyographic examination via insertion of needle electrodes into the CPM. In total, 46 CPMs (24 right, 22 left) were evaluated. PP stimulation produced both positive visual contractions and electromyographic (EMG) responses in 42 CPMs (2080 ± 1583 μV). EBSLN stimulation produced visual contractions of 28 CPMs and positive EMG responses in 35 CPMs (686 ± 630 μV). Stimulation of 45 RLNs produced visible contractions of 37 CPMs and positive EMG activity in 41 CPMs (337 ± 280 μV). Stimulation of 42 vagal nerves resulted in visible contractions of 36 CPMs and positive EMG responses in 37 CPMs (292 ± 229 μV). Motor activity was noted in 32 CPMs by both RLN and EBSLN stimulation, 9 CPMs by RLN stimulation, and 3 CPMs by EBSLN stimulation; 2 CPMs exhibited no response. This is the first study to show that the EBSLN contributes to motor innervation of the human CPM. The RLN, EBSLN, or both of the nerves innervate the 90, 75, and 70 % of the CPMs ipsilaterally, respectively.

Electrophysiologic alterations in the excitability of the sciatic and vagus nerves during early stages of sepsis

PubMed Central

Diniz, Lúcio Ricardo Leite; Portella, Viviane Gomes; da Silva Alves, Kerly Shamira; Araújo, Pâmella Cristina da Costa; de Albuquerque Júnior, Ricardo Luiz Cavalcanti; Cavalcante de Albuquerque, Aline Alice; Coelho-de-Souza, Andrelina Noronha; Leal-Cardoso, José Henrique

2018-01-01

Background Nonspecific and delayed diagnosis of neurologic damage contributes to the development of neuropathies in patients with severe sepsis. The present study assessed the electrophysiologic parameters related to the excitability and conductibility of sciatic and vagus nerves during early stages of sepsis. Materials and methods Twenty-four hours after sepsis induced by cecal ligation and puncture (CLP) model, sciatic and vagus nerves of septic (CLP group) and control (sham group) rats were removed, and selected electric stimulations were applied to measure the parameters of the first and second components of the compound action potential. The first component originated from fibers with motor and sensory functions (Types Aα and Aβ fibers) with a large conduction velocity (70–120 m/s), and the second component originated from fibers (Type Aγ) with sensorial function. To evaluate the presence of sensorial alterations, the sensitivity to non-noxious mechanical stimuli was measured by using the von Frey test. Hematoxylin and eosin staining of the nerves was performed. Results We observed an increase of rheobase followed by a decrease in the first component amplitude and a higher paw withdrawal threshold in response to the application of von Frey filaments in sciatic nerves from the CLP group compared to the sham group. Differently, a decrease in rheobase and an increase in the first component amplitude of vagal C fibers from CLP group were registered. No significant morphologic alteration was observed. Conclusion Our data showed that the electrophysiologic alterations in peripheral nerves vary with the fiber type and might be identified in the first 24 h of sepsis, before clinical signs of neuromuscular disorders. PMID:29731661

Is peroneal nerve injury associated with worse function after knee dislocation?

PubMed

Krych, Aaron J; Giuseffi, Steven A; Kuzma, Scott A; Stuart, Michael J; Levy, Bruce A

2014-09-01

Peroneal nerve palsy is a frequent and potentially disabling complication of multiligament knee dislocation, but little information exists on the degree to which patients recover motor or sensory function after this injury, and whether having this nerve injury--with or without complete recovery--is a predictor of inferior patient-reported outcome scores. The purposes of this study were to (1) report on motor and sensory recovery as well as patient-reported outcomes scores of patients with peroneal nerve injury from multiligament knee dislocation; (2) compare those endpoints between patients who had partial versus complete nerve injuries; and (3) compare patient-reported outcomes among patients who sustained peroneal nerve injuries after knee dislocation with a matched cohort of multiligament knee injuries without nerve injury. Thirty-two patients were identified, but five did not have 2-year followup and are excluded (16% lost to followup). Twenty-seven patients (24 male, three female) with peroneal nerve injury underwent multiligament knee reconstruction and were followed for 6.3 years (range, 2-18 years). Motor grades were assessed by examination and outcomes by International Knee Documentation Committee (IKDC) and Lysholm scores. Retrospectively, patients were divided into complete (n = 9) and partial nerve palsy (n = 18). Treatment for complete nerve palsy included an ankle-foot orthosis for all patients, nonoperative (one), neurolysis (two), tendon transfer (three), nerve transfer (one), and combined nerve/tendon transfer (one). Treatment for partial nerve palsy included nonoperative (12), neurolysis (four), nerve transfer (one), and combined nerve/tendon transfer (one). Furthermore, patients without nerve injury were matched by Schenck classification, age, and sex. Data were analyzed using univariate and multivariate models. Overall, 18 patients (69%) regained antigravity ankle dorsiflexion after treatment (three complete nerve palsy [38%] versus 15 partial

Sensory and motor peripheral nerve function and longitudinal changes in quadriceps strength.

PubMed

Ward, Rachel E; Boudreau, Robert M; Caserotti, Paolo; Harris, Tamara B; Zivkovic, Sasa; Goodpaster, Bret H; Satterfield, Suzanne; Kritchevsky, Stephen; Schwartz, Ann V; Vinik, Aaron I; Cauley, Jane A; Newman, Anne B; Strotmeyer, Elsa S

2015-04-01

Poor peripheral nerve function is common in older adults and may be a risk factor for strength decline, although this has not been assessed longitudinally. We assessed whether sensorimotor peripheral nerve function predicts strength longitudinally in 1,830 participants (age = 76.3 ± 2.8, body mass index = 27.2 ± 4.6kg/m(2), strength = 96.3 ± 34.7 Nm, 51.0% female, 34.8% black) from the Health ABC study. Isokinetic quadriceps strength was measured semiannually over 6 years. Peroneal motor nerve conduction amplitude and velocity were recorded. Sensory nerve function was assessed with 10-g and 1.4-g monofilaments and average vibration detection threshold at the toe. Lower-extremity neuropathy symptoms were self-reported. Worse vibration detection threshold predicted 2.4% lower strength in men and worse motor amplitude and two symptoms predicted 2.5% and 8.1% lower strength, respectively, in women. Initial 10-g monofilament insensitivity predicted 14.2% lower strength and faster strength decline in women and 6.6% lower strength in men (all p < .05). Poor nerve function predicted lower strength and faster strength decline. Future work should examine interventions aimed at preventing declines in strength in older adults with impaired nerve function. © The Author 2014. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Recurrent laryngeal nerve injury with incomplete loss of electromyography signal during monitored thyroidectomy-evaluation and outcome.

PubMed

Wu, Che-Wei; Hao, Min; Tian, Mengzi; Dionigi, Gianlorenzo; Tufano, Ralph P; Kim, Hoon Yub; Jung, Kwang Yoon; Liu, Xiaoli; Sun, Hui; Lu, I-Cheng; Chang, Pi-Ying; Chiang, Feng-Yu

2017-06-01

During monitored thyroidectomy, a partially or completely disrupted point of nerve conduction on the exposed recurrent laryngeal nerve (RLN) indicates true electrophysiologic nerve injury. Complete loss of signal (LOS; absolute threshold value <100 μV) at the end of operation often indicates a postoperative vocal cord (VC) palsy. However, the evaluation for the injured RLN with incomplete LOS and its functional outcome has not been well described. Three hundred twenty-three patients with 522 RLNs at risk who underwent standardized monitored thyroidectomy were enrolled. The RLN was routinely stimulated at the most proximal (R 2p signal) and distal (R 2d signal) ends of exposure after thyroid resection to determine if there was an injured point on the RLN. Pre- and postoperative VC function was routinely examined. Twenty-nine RLNs (5.6 %) were detected with an injury point. Five nerves had complete LOS and other 24 nerves had incomplete LOS where the R 2p /R 2d reduction (% of amplitude reduction compared with proximal to distal RLN stimulation) ranged from 22 to 79 %. Postoperative temporary VC palsy was noted in those five RLNs with complete LOS (final vagal signal, V 2  < 100 μV) and four RLNs with incomplete LOS (R 2p /R 2d reduction 62-79 %; V 2 181-490 μV). In the remaining 20 nerves with R 2p /R 2d reduction ≤53 % (V 2 373-1623 μV), all showed normal VC mobility. Overall, false negative results were found in two RLNs (0.4 %) featuring unchanged V 2 and R 2p /R 2d but developed VC palsy. Testing and comparing the R 2p /R 2d signal is a simple and useful procedure to evaluate RLN injury after its dissection and predict functional outcome. When the relative threshold value R 2p /R 2d reduction reaches over 60 %, surgeon should consider the possibility of postoperative VC palsy.

CNS BOLD fMRI effects of sham-controlled transcutaneous electrical nerve stimulation in the left outer auditory canal - a pilot study.

PubMed

Kraus, Thomas; Kiess, Olga; Hösl, Katharina; Terekhin, Pavel; Kornhuber, Johannes; Forster, Clemens

2013-09-01

It has recently been shown that electrical stimulation of sensory afferents within the outer auditory canal may facilitate a transcutaneous form of central nervous system stimulation. Functional magnetic resonance imaging (fMRI) blood oxygenation level dependent (BOLD) effects in limbic and temporal structures have been detected in two independent studies. In the present study, we investigated BOLD fMRI effects in response to transcutaneous electrical stimulation of two different zones in the left outer auditory canal. It is hypothesized that different central nervous system (CNS) activation patterns might help to localize and specifically stimulate auricular cutaneous vagal afferents. 16 healthy subjects aged between 20 and 37 years were divided into two groups. 8 subjects were stimulated in the anterior wall, the other 8 persons received transcutaneous vagus nervous stimulation (tVNS) at the posterior side of their left outer auditory canal. For sham control, both groups were also stimulated in an alternating manner on their corresponding ear lobe, which is generally known to be free of cutaneous vagal innervation. Functional MR data from the cortex and brain stem level were collected and a group analysis was performed. In most cortical areas, BOLD changes were in the opposite direction when comparing anterior vs. posterior stimulation of the left auditory canal. The only exception was in the insular cortex, where both stimulation types evoked positive BOLD changes. Prominent decreases of the BOLD signals were detected in the parahippocampal gyrus, posterior cingulate cortex and right thalamus (pulvinar) following anterior stimulation. In subcortical areas at brain stem level, a stronger BOLD decrease as compared with sham stimulation was found in the locus coeruleus and the solitary tract only during stimulation of the anterior part of the auditory canal. The results of the study are in line with previous fMRI studies showing robust BOLD signal decreases in

Tachycardia, reduced vagal capacity, and age-dependent ventricular dysfunction arising from diminished expression of the presynaptic choline transporter

PubMed Central

English, Brett A.; Appalsamy, Martin; Diedrich, Andre; Ruggiero, Alicia M.; Lund, David; Wright, Jane; Keller, Nancy R.; Louderback, Katherine M.; Robertson, David

2010-01-01

Healthy cardiovascular function relies on a balanced and responsive integration of noradrenergic and cholinergic innervation of the heart. High-affinity choline uptake by cholinergic terminals is pivotal for efficient ACh production and release. To date, the cardiovascular impact of diminished choline transporter (CHT) expression has not been directly examined, largely due to the transporter's inaccessibility in vivo. Here, we describe findings from cardiovascular experiments using transgenic mice that bear a CHT genetic deficiency. Whereas CHT knockout (CHT−/−) mice exhibit early postnatal lethality, CHT heterozygous (CHT+/−) mice survive, grow, and reproduce normally and exhibit normal spontaneous behaviors. However, the CHT+/− mouse heart displays significantly reduced levels of high-affinity choline uptake accompanied by significantly reduced levels of ACh. Telemeterized recordings of cardiovascular function in these mice revealed tachycardia and hypertension at rest. After treadmill exercise, CHT+/− mice exhibited slower heart rate recovery, consistent with a diminished cholinergic reserve, a contention validated through direct vagal nerve stimulation. Echocardiographic and histological experiments revealed an age-dependent decrease in fractional shortening, increased left ventricular dimensions, and increased ventricular fibrosis, consistent with ventricular dysfunction. These cardiovascular phenotypes of CHT+/− mice encourage an evaluation of humans bearing reduced CHT expression for their resiliency in maintaining proper heart function as well as risk for cardiovascular disease. PMID:20601463

The antiarrhythmic effect of vagal stimulation after acute coronary occlusion: Role of the heart rate.

PubMed

Manati, Waheed; Pineau, Julien; Doñate Puertas, Rosa; Morel, Elodie; Quadiri, Timour; Bui-Xuan, Bernard; Chevalier, Philippe

2018-01-03

Strong evidence suggests a causal link between autonomic disturbances and ventricular arrhythmias. However, the mechanisms underlying the antiarrhythmic effect of vagal stimulation are poorly understood. The vagal antiarrhythmic effect might be modulated by a decrease in heart rate. the proximal anterior interventricular artery was occluded in 16 pigs by clamping under general anaesthesia. Group 1: heart rates remained spontaneous (n = 6; 12 occlusions); Group 2: heart rates were fixed at 190 beats per minute (bpm) with atrial electrical stimulation (n = 10; 20 occlusions). Each pig received two occlusions, 30 min apart, one without and one with vagal stimulation (10 Hz, 2 ms, 5-20 mA). The antiarrhythmic effect of vagal activation was defined as the time to the appearance of ventricular fibrillation (VF) after occlusion. In Group 1, vagal stimulation triggered a significant decrease in basal heart rate (132 ± 4 vs. 110 ± 17 bpm, p < 0.05), and delayed the time to VF after coronary occlusion (1102 ± 85 vs. 925 ± 41 s, p < 0.05). In Group 2, vagal stimulation did not modify the time to VF (103 ± 39 vs. 91 ± 20 s). Analyses revealed that heart rate and the time to VF were positively linearly related. Maintaining a constant heart rate with atrial electrical stimulation in pigs prevented vagal stimulation from modifying the time to VF after acute coronary occlusion.

Voluntary control of breathing does not alter vagal modulation of heart rate

NASA Technical Reports Server (NTRS)

Patwardhan, A. R.; Evans, J. M.; Bruce, E. N.; Eckberg, D. L.; Knapp, C. F.

1995-01-01

Variations in respiratory pattern influence the heart rate spectrum. It has been suggested, hence, that metronomic respiration should be used to correctly assess vagal modulation of heart rate by using spectral analysis. On the other hand, breathing to a metronome has been reported to increase heart rate spectral power in the high- or respiratory frequency region; this finding has led to the suggestion that metronomic respiration enhances vagal tone or alters vagal modulation of heart rate. To investigate whether metronomic breathing complicates the interpretation of heart rate spectra by altering vagal modulation, we recorded the electrocardiogram and respiration from eight volunteers during three breathing trials of 10 min each: 1) spontaneous breathing (mean rate of 14.4 breaths/min); 2) breathing to a metronome at the rate of 15, 18, and 21 breaths/min for 2, 6, and 2 min, respectively; and 3) breathing to a metronome at the rate of 18 breaths/min for 10 min. Data were also collected from eight volunteers who breathed spontaneously for 20 min and breathed metronomically at each subject's mean spontaneous breathing frequency for 20 min. Results from the three 10-min breathing trials showed that heart rate power in the respiratory frequency region was smaller during metronomic breathing than during spontaneous breathing. This decrease could be explained fully by the higher breathing frequencies used during trials 2 and 3 of metronomic breathing. When the subjects breathed metronomically at each subject's mean breathing frequency, the heart rate powers during metronomic breathing were similar to those during spontaneous breathing. Our results suggest that vagal modulation of heart rate is not altered and vagal tone is not enhanced during metronomic breathing.

Biomechanical and functional variation in rat sciatic nerve following cuff electrode implantation

PubMed Central

2014-01-01

Background Nerve cuff electrodes are commonly and successfully used for stimulating peripheral nerves. On the other hand, they occasionally induce functional and morphological changes following chronic implantation, for reasons not always clear. We hypothesize that restriction of nerve mobility due to cuff implantation may alter nerve conduction. Methods We quantified acute changes in nerve-muscle electrophysiology, using electromyography, and nerve kinematics in anesthetized Sprague Dawley rat sciatic nerves during controlled hindlimb joint movement. We compared electrophysiological and biomechanical response in uncuffed nerves and those secured within a cuff electrode using analysis of variance (ANOVA) and regression analysis. Results Tethering resulting from cuff implantation resulted in altered nerve strain and a complex biomechanical environment during joint movement. Coincident with biomechanical changes, electromyography revealed significantly increased variability in the response of conduction latency and amplitude in cuffed, but not free, nerves following joint movement. Conclusion Our findings emphasize the importance of the mechanical interface between peripheral nerves and their devices on neurophysiological performance. This work has implications for nerve device design, implantation, and prediction of long-term efficacy. PMID:24758405

Development and Functional Organization of the Cranial Nerves in Lampreys.

PubMed

Pombal, Manuel A; Megías, Manuel

2018-04-16

Lampreys, together with hagfishes, are the only extant representatives of the oldest branch of vertebrates, the agnathans, which are the sister group of gnathostomes; therefore, studies on these animals are of great evolutionary significance. Lampreys exhibit a particular life cycle with remarkable changes in their behavior, concomitant, in part, with important modifications in the head and its musculature, which might influence the development of the cranial nerves. In this context, some cranial nerves such as the optic nerve and the ocular motor nerves, which develop slowly during an extremely long larval period lasting more than five years, have been more thoroughly investigated; however, much less experimental information is available about others, such as the facial or the hypoglossal nerves. In addition, the possible existence of a "true" accessory nerve in these animals is still a matter of conjecture. Although growing in last decades, investigations on the physiology of the lamprey cranial nerves is scanty. This review focuses on past and recent findings that have contributed to characterize the anatomical organization of the cranial nerves in lampreys, including their components and nuclei, and their relations in the brain; in addition, comments on their development and functional role are also included. Anat Rec, 2018. © 2018 Wiley Periodicals, Inc. © 2018 Wiley Periodicals, Inc.

Parental Socialization, Vagal Regulation, and Preschoolers' Anxious Difficulties: Direct Mothers and Moderated Fathers

ERIC Educational Resources Information Center

Hastings, Paul D.; Sullivan, Caroline; McShane, Kelly E.; Coplan, Robert J.; Utendale, William T.; Vyncke, Johanna D.

2008-01-01

Parental supportiveness and protective overcontrol and preschoolers' parasympathetic regulation were examined as predictors of temperamental inhibition, social wariness, and internalizing problems. Lower baseline vagal tone and weaker vagal suppression were expected to mark poorer dispositional self-regulatory capacity, leaving children more…

Caudal fourth ventricular administration of the AMPK activator 5-aminoimidazole-4-carboxamide-riboside regulates glucose and counterregulatory hormone profiles, dorsal vagal complex metabolosensory neuron function, and hypothalamic Fos expression.

PubMed

Ibrahim, Baher A; Tamrakar, Pratistha; Gujar, Amit D; Cherian, Ajeesh Koshy; Briski, Karen P

2013-09-01

This study investigated the hypothesis that estrogen controls hindbrain AMP-activated protein kinase (AMPK) activity and regulation of blood glucose, counterregulatory hormone secretion, and hypothalamic nerve cell transcriptional status. Dorsal vagal complex A2 noradrenergic neurons were laser microdissected from estradiol benzoate (E)- or oil (O)-implanted ovariectomized female rats after caudal fourth ventricular (CV4) delivery of the AMPK activator 5-aminoimidazole-4-carboxamide-riboside (AICAR), for Western blot analysis. E advanced AICAR-induced increases in A2 phospho-AMPK (pAMPK) expression and in blood glucose levels and was required for augmentation of Fos, estrogen receptor-α (ERα), monocarboxylate transporter-2, and glucose transporter-3 protein in A2 neurons and enhancement of corticosterone secretion by this treatment paradigm. CV4 AICAR also resulted in site-specific modifications in Fos immunolabeling of hypothalamic metabolic structures, including the paraventricular, ventromedial, and arcuate nuclei. The current studies demonstrate that estrogen regulates AMPK activation in caudal hindbrain A2 noradrenergic neurons during pharmacological replication of energy shortage in this area of the brain, and that this sensor is involved in neural regulation of glucostasis, in part, through control of corticosterone secretion. The data provide unique evidence that A2 neurons express both ERα and -β proteins and that AMPK upregulates cellular sensitivity to ERα-mediated signaling during simulated energy insufficiency. The results also imply that estrogen promotes glucose and lactate uptake by these cells under those conditions. Evidence for correlation between hindbrain AMPK and hypothalamic nerve cell genomic activation provides novel proof for functional connectivity between this hindbrain sensor and higher order metabolic brain loci while demonstrating a modulatory role for estrogen in this interaction. Copyright © 2013 Wiley Periodicals, Inc.

Vagal and sympathetic activity in burnouts during a mentally demanding workday.

PubMed

Zanstra, Ydwine J; Schellekens, Jan M H; Schaap, Cas; Kooistra, Libbe

2006-01-01

We study differences in task performance and related sympathetic-vagal reaction patterns between burnouts and controls during a mentally demanding workday. Thirty-nine adults with burnout and 40 healthy controls performed mental tasks during a simulated workday. At pretest, just before lunch (lunch test) and at the end of the day (posttest), a Stroop color word task was administered as a probe task. Efficiency (the relation between performance and effort during the probe task), performance (reaction time and errors), and effort (self-report) were measured, as well as cardiovascular indices of sympathetic (blood pressure) and vagal (respiratory sinus arrhythmia) activity. Performance and effort investment of both burnouts and controls did not differ during pretest. As the day progressed the performance of controls improved more than the performance of burnouts. Moreover, the control group showed a decrease of blood pressure in response to mental task demands, a decrease in respiratory sinus arrhythmia activity, and no change in experienced effort. In the burnout group, no change could be demonstrated in blood pressure, suggesting a sympathetic predominance in the sympathetic-vagal balance. Burnouts experienced an increase in effort and were more tired at the end of the workday. Burnouts and healthy controls differ in their pattern of sympathetic-vagal activity only after long-lasting work demands. Findings give limited support to Porges's view that in healthy subjects, the vagal system is more responsive to challenging task situations than in chronically stressed individuals. The distinction between two phases in the burnout on the basis of behavioral and physiological characteristics is discussed.

Enterocyte-afferent nerve interactions in dietary fat sensing.

PubMed

Mansouri, A; Langhans, W

2014-09-01

The central nervous system (CNS) constantly monitors nutrient availability in the body and, in particular, in the gastrointestinal (GI) tract to regulate nutrient and energy homeostasis. Extrinsic parasympathetic and sympathetic nerves are crucial for CNS nutrient sensing in the GI tract. These extrinsic afferent nerves detect the nature and amount of nutrients present in the GI tract and relay the information to the brain, which controls energy intake and expenditure accordingly. Dietary fat and fatty acids are sensed through various direct and indirect mechanisms. These sensing processes involve the binding of fatty acids to specific G protein-coupled receptors expressed either on the afferent nerve fibres or on the surface of enteroendocrine cells that release gut peptides, which themselves can modulate afferent nerve activity through their cognate receptors or have endocrine effects directly on the brain. Further dietary fat sensing mechanisms that are related to enterocyte fat handling and metabolism involve the release of several possible chemical mediators such as fatty acid ethanolamides or apolipoprotein A-IV. We here present evidence for yet another mechanism that may be based on ketone bodies resulting from enterocyte oxidation of dietary fat-derived fatty acids. The presently available evidence suggests that sympathetic rather than vagal afferents are involved, but further experiments are necessary to critically examine this concept. © 2014 John Wiley & Sons Ltd.

Cardiac vagal tone is correlated with selective attention to neutral distractors under load.

PubMed

Park, Gewnhi; Vasey, Michael W; Van Bavel, Jay J; Thayer, Julian F

2013-04-01

We examined whether cardiac vagal tone (indexed by heart rate variability, HRV) was associated with the functioning of selective attention under load. Participants were instructed to detect a target letter among letter strings superimposed on either fearful or neutral distractor faces. Under low load, when letter strings consisted of six target letters, there was no difference between people with high and low HRV on task performance. Under high load, when letter strings consisted of one target letter and five nontarget letters, people with high HRV were faster in trials with neutral distractors, but not with fearful distractors. However, people with low HRV were slower in trials with both fearful and neutral distractors. The current research suggests cardiac vagal tone is associated with successful control of selective attention critical for goal-directed behavior, and its impact is greater when fewer cognitive resources are available. Copyright © 2013 Society for Psychophysiological Research.

Intraoperative electrostimulation objectifies the assessment of functional nerve preservation after mesorectal excision.

PubMed

Kneist, W; Junginger, T

2007-06-01

To improve nerve-sparing surgery, intraoperative electrical stimulation of pelvic autonomic nerves (INS) has been proposed in urology, gynecology, and visceral surgery. The aim of this study was to assess the impact of INS while monitoring intravesical pressure on the accurate evaluation of pelvic autonomic nerve preservation (PANP) after mesorectal excision. It was sought to determine whether this confirmation is useful in the prediction of postoperative urinary function. Sixty-two patients with mesorectal exzision for rectal cancer were examined prospectively. PANP was assessed visually by the surgeon and with INS. Bladder function was evaluated by post voiding residual volume measurement, rate of recatheterization, rate of long-term urinary catheterisation, and the international prostatic symptom score with quality of life index. INS confirmed bilateral preservation of parasympathetic nerves in 46 patients (74%), and in 10 patients (16%) in at least one side. In six patients (10%), INS failed to confirm PANP. Eleven patients (18%) developed urinary symptoms postoperatively. INS results had a higher sensitivity than visual assessment by the surgeon (82 vs 46%). Values for specificity ranged at 90 and 92%, respectively. Accuracy of INS in predicting PANP was higher (88 vs 83%). The correlation between urinary function and the findings on INS was good (kappa-value: 0.65), correlation between urinary function and visual assessment by the surgeon was fair (kappa-value: 0.40). INS, while monitoring intravesical pressure, accurately predicts bladder function after mesorectal excision. It may provide further insight into pelvic autonomic nerve sparing techniques.

"In Situ Vascular Nerve Graft" for Restoration of Intrinsic Hand Function: An Anatomical Study.

PubMed

Mozaffarian, Kamran; Zemoodeh, Hamid Reza; Zarenezhad, Mohammad; Owji, Mohammad

2018-06-01

In combined high median and ulnar nerve injury, transfer of the posterior interosseous nerve branches to the motor branch of the ulnar nerve (MUN) is previously described in order to restore intrinsic hand function. In this operation a segment of sural nerve graft is required to close the gap between the donor and recipient nerves. However the thenar muscles are not innervated by this nerve transfer. The aim of the present study was to evaluate whether the superficial radial nerve (SRN) can be used as an "in situ vascular nerve graft" to connect the donor nerves to the MUN and the motor branch of median nerve (MMN) at the same time in order to address all denervated intrinsic and thenar muscles. Twenty fresh male cadavers were dissected in order to evaluate the feasibility of this modification of technique. The size of nerve branches, the number of axons and the tension at repair site were evaluated. This nerve transfer was technically feasible in all specimens. There was no significant size mismatch between the donor and recipient nerves Conclusions: The possible advantages of this modification include innervation of both median and ulnar nerve innervated intrinsic muscles, preservation of vascularity of the nerve graft which might accelerate the nerve regeneration, avoidance of leg incision and therefore the possibility of performing surgery under regional instead of general anesthesia. Briefly, this novel technique is a viable option which can be used instead of conventional nerve graft in some brachial plexus or combined high median and ulnar nerve injuries when restoration of intrinsic hand function by transfer of posterior interosseous nerve branches is attempted.

Chitin biological absorbable catheters bridging sural nerve grafts transplanted into sciatic nerve defects promote nerve regeneration.

PubMed

Wang, Zhi-Yong; Wang, Jian-Wei; Qin, Li-Hua; Zhang, Wei-Guang; Zhang, Pei-Xun; Jiang, Bao-Guo

2018-06-01

To investigate the efficacy of chitin biological absorbable catheters in a rat model of autologous nerve transplantation. A segment of sciatic nerve was removed to produce a sciatic nerve defect, and the sural nerve was cut from the ipsilateral leg and used as a graft to bridge the defect, with or without use of a chitin biological absorbable catheter surrounding the graft. The number and morphology of regenerating myelinated fibers, nerve conduction velocity, nerve function index, triceps surae muscle morphology, and sensory function were evaluated at 9 and 12 months after surgery. All of the above parameters were improved in rats in which the nerve graft was bridged with chitin biological absorbable catheters compared with rats without catheters. The results of this study indicate that use of chitin biological absorbable catheters to surround sural nerve grafts bridging sciatic nerve defects promotes recovery of structural, motor, and sensory function and improves muscle fiber morphology. © 2018 John Wiley & Sons Ltd.

The split hypoglossal nerve versus the cross-face nerve graft to supply the free functional muscle transfer for facial reanimation: A comparative study.

PubMed

Amer, Tarek A; El Kholy, Mohamed S

2018-05-01

Long-standing cases of facial paralysis are currently treated with free functional muscle transfer. Several nerves are mentioned in the literature to supply the free muscle transfer. The aim of this study is to compare the split hypoglossal nerve and the cross-face nerve graft to supply the free functional muscle transfer in facial reanimation. Of 94 patients with long-standing, unilateral facial palsy, 49 were treated using the latissimus dorsi muscle supplied by the split hypoglossal nerve, and 45 patients were treated using the latissmus dorsi muscle supplied by healthy contralateral buccal branch of the facial nerve. The excursion gained by the free muscle transfer supplied by the split hypoglossal nerve (mean 19.20 ± 6.321) was significantly higher (P value 0.001) than that obtained by the contralateral buccal branch of the facial nerve (mean 14.59 ± 6.245). The split hypoglossal nerve appears to be a good possible option to supply the free vascularised muscle transfer in facial reanimation. It yields a stronger excursion in less time than the contralateral cross-face nerve graft. Copyright © 2018 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Assessment of nerve regeneration across nerve allografts treated with tacrolimus.

PubMed

Haisheng, Han; Songjie, Zuo; Xin, Li

2008-01-01

Although regeneration of nerve allotransplant is a major concern in the clinic, there have been few papers quantitatively assessing functional recovery of animals' nerve allografts in the long term. In this study, functional recovery, histopathological study, and immunohistochemistry changes of rat nerve allograft with FK506 were investigated up to 12 weeks without slaughtering. C57 and SD rats were used for transplantation. The donor's nerve was sliced and transplanted into the recipient. The sciatic nerve was epineurally sutured with 10-0 nylon. In total, 30 models of transplantation were performed and divided into 3 groups that were either treated with FK506 or not. Functional recovery of the grafted nerve was serially assessed by the pin click test, walking track analysis and electrophysiological evaluations. A histopathological study and immunohistochemistry study were done in the all of the models. Nerve allografts treated with FK506 have no immune rejection through 12 weeks. Sensibility had similarly improved in both isografts and allografts. There has been no difference in each graft. Walk track analysis demonstrates significant recovery of motor function of the nerve graft. No histological results of difference were found up to 12 weeks in each graft. In the rodent nerve graft model, FK506 prevented nerve allograft rejection across a major histocompatibility barrier. Sensory recovery seems to be superior to motor function. Nerve isograft and allograft treated with FK506 have no significant difference in function recovery, histopathological result, and immunohistochemistry changes.

Transcutaneous Vagus Nerve Stimulation: A Promising Method for Treatment of Autism Spectrum Disorders

PubMed Central

Jin, Yu; Kong, Jian

2017-01-01

Transcutaneous Vagus Nerve Stimulation (tVNS) on the auricular branch of the vagus nerve has been receiving attention due to its therapeutic potential for neuropsychiatric disorders. Although the mechanism of tVNS is not yet completely understood, studies have demonstrated the potential role of vagal afferent nerve stimulation in the regulation of mood and visceral state associated with social communication. In addition, a growing body of evidence shows that tVNS can activate the brain regions associated with Autism Spectrum Disorder (ASD), trigger neuroimmune modulation and produce treatment effects for comorbid disorders of ASD such as epilepsy and depression. We thus hypothesize that tVNS may be a promising treatment for ASD, not only for comorbid epilepsy and depression, but also for the core symptoms of ASD. The goal of this manuscript is to summarize the findings and rationales for applying tVNS to treat ASD and propose potential parameters for tVNS treatment of ASD. PMID:28163670

Cardiac vagal flexibility and accurate personality impressions: Examining a physiological correlate of the good judge.

PubMed

Human, Lauren J; Mendes, Wendy Berry

2018-02-23

Research has long sought to identify which individuals are best at accurately perceiving others' personalities or are good judges, yet consistent predictors of this ability have been difficult to find. In the current studies, we revisit this question by examining a novel physiological correlate of social sensitivity, cardiac vagal flexibility, which reflects dynamic modulation of cardiac vagal control. We examined whether greater cardiac vagal flexibility was associated with forming more accurate personality impressions, defined as viewing targets more in line with their distinctive self-reported profile of traits, in two studies, including a thin-slice video perceptions study (N = 109) and a dyadic interaction study (N = 175). Across studies, we found that individuals higher in vagal flexibility formed significantly more accurate first impressions of others' more observable personality traits (e.g., extraversion, creativity, warmth). These associations held while including a range of relevant covariates, including cardiac vagal tone, sympathetic activation, and gender. In sum, social sensitivity as indexed by cardiac vagal flexibility is linked to forming more accurate impressions of others' observable traits, shedding light on a characteristic that may help to identify the elusive good judge and providing insight into its neurobiological underpinnings. © 2018 Wiley Periodicals, Inc.

VERSATILE, HIGH-RESOLUTION ANTEROGRADE LABELING OF VAGAL EFFERENT PROJECTIONS WITH DEXTRAN AMINES

PubMed Central

Walter, Gary C.; Phillips, Robert J.; Baronowsky, Elizabeth A.; Powley, Terry L.

2009-01-01

None of the anterograde tracers used to label and investigate vagal preganglionic neurons projecting to the viscera has proved optimal for routine and extensive labeling of autonomic terminal fields. To identify an alternative tracer protocol, the present experiment evaluated whether dextran conjugates, which have produced superior results in the CNS, might yield widespread and effective labeling of long, fine-caliber vagal efferents in the peripheral nervous system. The dextran conjugates that were evaluated proved reliable and versatile for labeling the motor neuron pool in its entirety, for single- and multiple-labeling protocols, for both conventional and confocal fluorescence microscopy, and for permanent labeling protocols for brightfield microscopy of the projections to the gastrointestinal (GI) tract. Using a standard ABC kit followed by visualization with DAB as the chromagen, Golgi-like labeling of the vagal efferent terminal fields in the GI wall was achieved with the biotinylated dextrans. The definition of individual terminal varicosities was so sharp and detailed that it was routinely practical to examine the relationship of putative vagal efferent contacts (by the criteria of high magnification light microscopy) with the dendritic and somatic architecture of counterstained neurons in the myenteric plexus. Overall, dextran conjugates provide high-definition labeling of an extensive vagal motor pool in the GI tract, and offer considerable versatility when multiple-staining protocols are needed to elucidate the complexities of the innervation of the gut. PMID:19056424

Carotid Space Mass Proximal to Vagus Nerve Causing Asystole and Syncope.

PubMed

Leviter, Julie; Wiznia, Daniel H

2016-01-01

Manipulation of vagal nerve rootlets, whether surgical or through mass effect of a neoplasm, can result in asystole and hypotension, accompanied by ST depression and right bundle branch block. There are few case reports of a neoplasm causing these effects, and this case describes a patient with such a mass presenting with syncopal episodes. A 43-year-old man with a past medical history of HIV, bipolar disorder, and epilepsy was admitted to the neurology service for a video electroencephalogram (vEEG) to characterize syncopal episodes that were felt to be epileptic in origin. During the study, he experienced symptoms of his typical aura, which correlated with a transient symptomatic high degree AV block on telemetry, and an absence of epileptic findings on vEEG. Magnetic Resonance Imaging (MRI) of the brain showed a mass in the left posterior carotid space at the skull base. The patient underwent permanent dual chamber MRI-compatible pacemaker placement for his heart block. His syncopal episodes resolved, but presyncopal symptoms persisted. We discuss the presentation and treatment of vagal neoplasms.

Vagal afferent fibres determine the oxytocin-induced modulation of gastric tone

PubMed Central

Holmes, Gregory M; Browning, Kirsteen N; Babic, Tanja; Fortna, Samuel R; Coleman, F Holly; Travagli, R Alberto

2013-01-01

Oxytocin (OXT) inputs to the dorsal vagal complex (DVC; nucleus of the tractus solitarius (NTS) dorsal motor nucleus of the vagus (DMV) and area postrema) decrease gastric tone and motility. Our first aim was to investigate the mechanism(s) of OXT-induced gastric relaxation. We demonstrated recently that vagal afferent inputs modulate NTS–DMV synapses involved in gastric and pancreatic reflexes via group II metabotropic glutamate receptors (mGluRs). Our second aim was to investigate whether group II mGluRs similarly influence the response of vagal motoneurons to OXT. Microinjection of OXT in the DVC decreased gastric tone in a dose-dependent manner. The OXT-induced gastric relaxation was enhanced following bethanechol and reduced by l-NAME administration, suggesting a nitrergic mechanism of gastroinhibition. DVC application of the group II mGluR antagonist EGLU induced a gastroinhibition that was not dose dependent and shifted the gastric effects of OXT to a cholinergic-mediated mechanism. Evoked and miniature GABAergic synaptic currents between NTS and identified gastric-projecting DMV neurones were not affected by OXT in any neurones tested, unless the brainstem slice was (a) pretreated with EGLU or (b) derived from rats that had earlier received a surgical vagal deafferentation. Conversely, OXT inhibited glutamatergic currents even in naive slices, but their responses were unaffected by EGLU pretreatment. These results suggest that the OXT-induced gastroinhibition is mediated by activation of the NANC pathway. Inhibition of brainstem group II mGluRs, however, uncovers the ability of OXT to modulate GABAergic transmission between the NTS and DMV, resulting in the engagement of an otherwise silent cholinergic vagal neurocircuit. PMID:23587885

Vagal innervation of the hepatic portal vein and liver is not necessary for Roux-en-Y gastric bypass surgery-induced hypophagia, weight loss, and hypermetabolism.

PubMed

Shin, Andrew C; Zheng, Huiyuan; Berthoud, Hans-Rudolf

2012-02-01

To determine the role of the common hepatic branch of the abdominal vagus on the beneficial effects of Roux-en-Y gastric bypass (RYGB) on weight loss, food intake, food choice, and energy expenditure in a rat model. Although changes in gut hormone patterns are the leading candidates in RYGB's effects on appetite, weight loss, and reversal of diabetes, a potential role for afferent signaling through the vagal hepatic branch potentially sensing glucose levels in the hepatic portal vein has recently been suggested in a mouse model of RYGB. Male Sprague-Dawley rats underwent either RYGB alone (RYGB; n = 7), RYGB + common hepatic branch vagotomy (RYGB + HV; n = 6), or sham procedure (sham; n = 9). Body weight, body composition, meal patterns, food choice, energy expenditure, and fecal energy loss were monitored up to 3 months after intervention. Both RYGB and RYGB + HV significantly reduced body weight, adiposity, meal size, and fat preference, and increased satiety, energy expenditure, and respiratory exchange rate compared with sham procedure, and there were no significant differences in these effects between RYGB and RYGB + HV rats. Integrity of vagal nerve supply to the liver, hepatic portal vein, and the proximal duodenum provided by the common hepatic branch is not necessary for RYGB to reduce food intake and body weight or increase energy expenditure. Specifically, it is unlikely that a hepatic portal vein glucose sensor signaling RYGB-induced increased intestinal gluconeogenesis to the brain depends on vagal afferent fibers.

Low to high frequency ratio of heart rate variability spectra fails to describe sympatho-vagal balance in cardiac patients.

PubMed

Milicević, Goran

2005-06-01

Heart rate variability (HRV) reflects an influence of autonomic nervous system on heart work. In healthy subjects, ratio between low and high frequency components (LF/HF ratio) of HRV spectra represents a measure of sympatho-vagal balance. The ratio was defined by the authorities as an useful clinical tool, but it seems that it fails to summarise sympatho-vagal balance in a clinical setting. Value of the method was re-evaluated in several categories of cardiac patients. HRV was analysed from 24-hour Holter ECGs in 132 healthy subjects, and 2159 cardiac patients dichotomised by gender, median of age, diagnosis of myocardial infarction or coronary artery surgery, left ventricular systolic function and divided by overall HRV into several categories. In healthy subjects, LF/HF ratio correlated with overall HRV negatively, as expected. The paradoxical finding was obtained in cardiac patients; the lower the overall HRV and the time-domain indices of vagal modulation activity were the lower the LF/HF ratio was. If used as a measure of sympatho-vagal balance, long-term recordings of LF/HF ratio contradict to clinical finding and time-domain HRV indices in cardiac patients. The ratio cannot therefore be used as a reliable marker of autonomic activity in a clinical setting.

The effects of hemostatic agents on peripheral nerve function: an experimental study.

PubMed

Alkan, Alper; Inal, Samet; Yildirim, Mehmet; Baş, Burcu; Ağar, Erdal

2007-04-01

In the practice of oral and maxillofacial surgery, hemostatic agents are sometimes placed in close proximity to peripheral nerves. In the present study, we evaluated immediate and delayed effects of 4 hemostatic agents (oxidized regenerated cellulose, 5% colloid silver-added gelatine sponge, bovine collagen, bone wax) on peripheral nerve function. A total of 25 rat sciatic nerves were prepared, and the amplitudes were recorded with a physiological data acquisition system. Animals were randomly assigned to 5 groups: control, oxidized regenerated cellulose, gelatine sponge, bone wax, and bovine collagen. The first hour records are defined as immediate effects of these hemostatic agents on nerve function. The animals were then allowed to recover for 4 weeks. At the end of this period, the same surgical and recording procedures were performed. These final records are defined as delayed effects of hemostatic agents on nerve function. According to nerve conduction velocity (NCV) and compound action potential (CAP) values of the experimental groups, early and delayed effects of each hemostatic agent were statistically compared with Bonferroni corrected test (P < .05). Statistically, NCV was significantly reduced, and the CAP was significantly increased 1 hour after surgery (P < .05) in the group of oxidized regenerated cellulose. However, there were no significant differences after 4 weeks compared with the first records. In the gelatine sponge group, CAP was significantly increased 4 weeks after the application. In the bovine collagen and bone wax groups, NCV and CAP values (1 hour and 4 weeks after the application) were not statistically significant compared with initial control records. The present study shows that bovine collagen is the most suitable hemostatic agent applicable for peripheral nerves.

The contribution of coping related variables and cardiac vagal activity on the performance of a dart throwing task under pressure.

PubMed

Mosley, Emma; Laborde, Sylvain; Kavanagh, Emma

2017-10-01

The aims of this study were 1) to assess the predictive role of coping related variables (CRV) on cardiac vagal activity (derived from heart rate variability), and 2) to investigate the influence of CRV (including cardiac vagal activity) on a dart throwing task under low pressure (LP) and high pressure (HP) conditions. Participants (n=51) completed trait CRV questionnaires: Decision Specific Reinvestment Scale, Movement Specific Reinvestment Scale and Trait Emotional Intelligence Questionnaire. They competed in a dart throwing task under LP and HP conditions. Cardiac vagal activity measurements were taken at resting, task and during recovery for 5min. Self-reported ratings of stress were recorded at three time points via a visual analogue scale. Upon completion of the task, self-report measures of motivation, stress appraisal, attention, perceived pressure and dart throwing experience were completed. Results indicated that resting cardiac vagal activity had no predictors. Task cardiac vagal activity was predicted by resting cardiac vagal activity in both pressure conditions with the addition of a trait CRV in HP. Post task cardiac vagal activity was predicted by resting cardiac vagal activity in both conditions with the addition of a trait CRV in HP. Cardiac vagal reactivity (difference from resting to task) was predicted by a trait CRV in HP conditions. Cardiac vagal recovery (difference from task to post task) was predicted by a state CRV only in LP. Dart throwing task performance was predicted by a combination of both CRV and cardiac vagal activity. The current research suggests that coping related variables and cardiac vagal activity influence dart throwing task performance differently dependent on pressure condition. Copyright © 2017 Elsevier Inc. All rights reserved.

Stimulus electrodiagnosis and motor and functional evaluations during ulnar nerve recovery

PubMed Central

Fernandes, Luciane F. R. M.; Oliveira, Nuno M. L.; Pelet, Danyelle C. S.; Cunha, Agnes F. S.; Grecco, Marco A. S.; Souza, Luciane A. P. S.

2016-01-01

BACKGROUND: Distal ulnar nerve injury leads to impairment of hand function due to motor and sensorial changes. Stimulus electrodiagnosis (SE) is a method of assessing and monitoring the development of this type of injury. OBJECTIVE: To identify the most sensitive electrodiagnostic parameters to evaluate ulnar nerve recovery and to correlate these parameters (Rheobase, Chronaxie, and Accommodation) with motor function evaluations. METHOD: A prospective cohort study of ten patients submitted to ulnar neurorrhaphy and evaluated using electrodiagnosis and motor assessment at two moments of neural recovery. A functional evaluation using the DASH questionnaire (Disability of the Arm, Shoulder, and Hand) was conducted at the end to establish the functional status of the upper limb. RESULTS: There was significant reduction only in the Chronaxie values in relation to time of injury and side (with and without lesion), as well as significant correlation of Chronaxie with the motor domain score. CONCLUSION: Chronaxie was the most sensitive SE parameter for detecting differences in neuromuscular responses during the ulnar nerve recovery process and it was the only parameter correlated with the motor assessment. PMID:26786072

The vagus and recurrent laryngeal nerves in the rodent experimental model of esophageal atresia.

PubMed

Qi, B Q; Merei, J; Farmer, P; Hasthorpe, S; Myers, N A; Beasley, S W; Hutson, J M

1997-11-01

After surgical correction of their esophageal atresia and tracheoesophageal fistula (EA-TEF), many patients exhibit evidence of esophageal dysmotility. Controversy exists as to whether the esophageal motility disorders result from denervation caused by surgery or from an inherent abnormal innervation of the esophagus. The present study used an Adriamycin-induced EA-TEF fetal rat model to trace the course and branching of both the vagus and recurrent laryngeal nerves. Abnormalities observed in EA-TEF rat fetuses include: (1) fewer branches from both recurrent laryngeal nerves; (2) deviation of the left vagus from its normal course below the aorta, passing behind the fistula to approach and join with the right vagus to form a single nerve trunk on the right side of the esophagus; (3) relatively few branches from the single vagal nerve trunk (composed of fibers of the left and the right vagus) on the surface of the lower esophagus. Fetuses affected by EA-TEF have inherent abnormalities in the course and branching pattern of the vagus nerves as they descend through the thorax, culminating in a deficient extrinsic nerve fiber plexus in the lower esophagus. These observations may account for the esophageal motility disorders seen in patients who have EA-TEF even before surgical intervention.

Too much of a good thing? Cardiac vagal tone's nonlinear relationship with well-being.

PubMed

Kogan, Aleksandr; Gruber, June; Shallcross, Amanda J; Ford, Brett Q; Mauss, Iris B

2013-08-01

Parasympathetic regulation of heart rate through the vagus nerve--often measured as resting respiratory sinus arrhythmia or cardiac vagal tone (CVT)--is a key biological correlate of psychological well-being. However, recent theorizing has suggested that many biological and psychological processes can become maladaptive when they reach extreme levels. This raises the possibility that CVT might not have an unmitigated positive relationship with well-being. In line with this reasoning, across 231 adult participants (Mage = 40.02 years; 52% female), we found that CVT was quadratically related to multiple measures of well-being, including life satisfaction and depressive symptoms. Individuals with moderate CVT had higher well-being than those with low or high CVT. These results provide the first direct evidence of a nonlinear relationship between CVT and well-being, adding to a growing body of research that has suggested some biological processes may cease being adaptive when they reach extreme levels. PsycINFO Database Record (c) 2013 APA, all rights reserved.

The anxiolytic effect of Bifidobacterium longum NCC3001 involves vagal pathways for gut-brain communication.

PubMed

Bercik, P; Park, A J; Sinclair, D; Khoshdel, A; Lu, J; Huang, X; Deng, Y; Blennerhassett, P A; Fahnestock, M; Moine, D; Berger, B; Huizinga, J D; Kunze, W; McLean, P G; Bergonzelli, G E; Collins, S M; Verdu, E F

2011-12-01

The probiotic Bifidobacterium longum NCC3001 normalizes anxiety-like behavior and hippocampal brain derived neurotrophic factor (BDNF) in mice with infectious colitis. Using a model of chemical colitis we test whether the anxiolytic effect of B. longum involves vagal integrity, and changes in neural cell function. Methods  Mice received dextran sodium sulfate (DSS, 3%) in drinking water during three 1-week cycles. Bifidobacterium longum or placebo were gavaged daily during the last cycle. Some mice underwent subdiaphragmatic vagotomy. Behavior was assessed by step-down test, inflammation by myeloperoxidase (MPO) activity and histology. BDNF mRNA was measured in neuroblastoma SH-SY5Y cells after incubation with sera from B. longum- or placebo-treated mice. The effect of B. longum on myenteric neuron excitability was measured using intracellular microelectrodes. Chronic colitis was associated with anxiety-like behavior, which was absent in previously vagotomized mice. B. longum normalized behavior but had no effect on MPO activity or histological scores. Its anxiolytic effect was absent in mice with established anxiety that were vagotomized before the third DSS cycle. B. longum metabolites did not affect BDNF mRNA expression in SH-SY5Y cells but decreased excitability of enteric neurons. In this colitis model, anxiety-like behavior is vagally mediated. The anxiolytic effect of B. longum requires vagal integrity but does not involve gut immuno-modulation or production of BDNF by neuronal cells. As B. longum decreases excitability of enteric neurons, it may signal to the central nervous system by activating vagal pathways at the level of the enteric nervous system. © 2011 Blackwell Publishing Ltd.

Functional evaluation of peripheral nerve regeneration and target reinnervation in animal models: a critical overview.

PubMed

Navarro, Xavier

2016-02-01

Peripheral nerve injuries usually lead to severe loss of motor, sensory and autonomic functions in the patients. Due to the complex requirements for adequate axonal regeneration, functional recovery is often poorly achieved. Experimental models are useful to investigate the mechanisms related to axonal regeneration and tissue reinnervation, and to test new therapeutic strategies to improve functional recovery. Therefore, objective and reliable evaluation methods should be applied for the assessment of regeneration and function restitution after nerve injury in animal models. This review gives an overview of the most useful methods to assess nerve regeneration, target reinnervation and recovery of complex sensory and motor functions, their values and limitations. The selection of methods has to be adequate to the main objective of the research study, either enhancement of axonal regeneration, improving regeneration and reinnervation of target organs by different types of nerve fibres, or increasing recovery of complex sensory and motor functions. It is generally recommended to use more than one functional method for each purpose, and also to perform morphological studies of the injured nerve and the reinnervated targets. © 2015 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Fibrin matrices with affinity-based delivery systems and neurotrophic factors promote functional nerve regeneration.

PubMed

Wood, Matthew D; MacEwan, Matthew R; French, Alexander R; Moore, Amy M; Hunter, Daniel A; Mackinnon, Susan E; Moran, Daniel W; Borschel, Gregory H; Sakiyama-Elbert, Shelly E

2010-08-15

Glial-derived neurotrophic factor (GDNF) and nerve growth factor (NGF) have both been shown to enhance peripheral nerve regeneration following injury and target different neuronal populations. The delivery of either growth factor at the site of injury may, therefore, result in quantitative differences in motor nerve regeneration and functional recovery. In this study we evaluated the effect of affinity-based delivery of GDNF or NGF from fibrin-filled nerve guidance conduits (NGCs) on motor nerve regeneration and functional recovery in a 13 mm rat sciatic nerve defect. Seven experimental groups were evaluated consisting of GDNF or NGF and the affinity-based delivery system (DS) within NGCs, control groups excluding the DS and/or growth factor, and nerve isografts. Groups with growth factor in the conduit demonstrated equivalent or superior performance in behavioral tests and relative muscle mass measurements compared to isografts at 12 weeks. Additionally, groups with GDNF demonstrated greater specific twitch and tetanic force production in extensor digitorum longus (EDL) muscle than the isograft control, while groups with NGF produced demonstrated similar force production compared to the isograft control. Assessment of motor axon regeneration by retrograde labeling further revealed that the number of ventral horn neurons regenerating across NGCs containing GDNF and NGF DS was similar to the isograft group and these counts were greater than the groups without growth factor. Overall, the GDNF DS group demonstrated superior functional recovery and equivalent motor nerve regeneration compared to the isograft control, suggesting it has potential as a treatment for motor nerve injury.

A Little Goes a Long Way: Low Working Memory Load Is Associated with Optimal Distractor Inhibition and Increased Vagal Control under Anxiety.

PubMed

Spangler, Derek P; Friedman, Bruce H

2017-01-01

Anxiety impairs both inhibition of distraction and attentional focus. It is unclear whether these impairments are reduced or exacerbated when loading working memory with non-affective information. Cardiac vagal control has been related to top-down regulation of anxiety; therefore, vagal control may reflect load-related inhibition of distraction under anxiety. The present study examined whether: (1) the enhancing and impairing effects of load on inhibition exist together in a non-linear function, (2) there is a similar association between inhibition and concurrent vagal control under anxiety. During anxiogenic threat-of-noise, 116 subjects maintained a digit series of varying lengths (0, 2, 4, and 6 digits) while completing a visual flanker task. The task was broken into four blocks, with a baseline period preceding each. Electrocardiography was acquired throughout to quantify vagal control as high-frequency heart rate variability (HRV). There were significant quadratic relations of working memory load to flanker performance and to HRV, but no associations between HRV and performance. Results indicate that low load was associated with relatively better inhibition and increased HRV. These findings suggest that attentional performance under anxiety depends on the availability of working memory resources, which might be reflected by vagal control. These results have implications for treating anxiety disorders, in which regulation of anxiety can be optimized for attentional focus.

A Little Goes a Long Way: Low Working Memory Load Is Associated with Optimal Distractor Inhibition and Increased Vagal Control under Anxiety

PubMed Central

Spangler, Derek P.; Friedman, Bruce H.

2017-01-01

Anxiety impairs both inhibition of distraction and attentional focus. It is unclear whether these impairments are reduced or exacerbated when loading working memory with non-affective information. Cardiac vagal control has been related to top–down regulation of anxiety; therefore, vagal control may reflect load-related inhibition of distraction under anxiety. The present study examined whether: (1) the enhancing and impairing effects of load on inhibition exist together in a non-linear function, (2) there is a similar association between inhibition and concurrent vagal control under anxiety. During anxiogenic threat-of-noise, 116 subjects maintained a digit series of varying lengths (0, 2, 4, and 6 digits) while completing a visual flanker task. The task was broken into four blocks, with a baseline period preceding each. Electrocardiography was acquired throughout to quantify vagal control as high-frequency heart rate variability (HRV). There were significant quadratic relations of working memory load to flanker performance and to HRV, but no associations between HRV and performance. Results indicate that low load was associated with relatively better inhibition and increased HRV. These findings suggest that attentional performance under anxiety depends on the availability of working memory resources, which might be reflected by vagal control. These results have implications for treating anxiety disorders, in which regulation of anxiety can be optimized for attentional focus. PMID:28217091

Mothers' responses to children's negative emotions and child emotion regulation: the moderating role of vagal suppression.

PubMed

Perry, Nicole B; Calkins, Susan D; Nelson, Jackie A; Leerkes, Esther M; Marcovitch, Stuart

2012-07-01

The current study examined the moderating effect of children's cardiac vagal suppression on the association between maternal socialization of negative emotions (supportive and nonsupportive responses) and children's emotion regulation behaviors. One hundred and ninety-seven 4-year-olds and their mothers participated. Mothers reported on their reactions to children's negative emotions and children's regulatory behaviors. Observed distraction, an adaptive self-regulatory strategy, and vagal suppression were assessed during a laboratory task designed to elicit frustration. Results indicated that children's vagal suppression moderated the association between mothers' nonsupportive emotion socialization and children's emotion regulation behaviors such that nonsupportive reactions to negative emotions predicted lower observed distraction and lower reported emotion regulation behaviors when children displayed lower levels of vagal suppression. No interaction was found between supportive maternal emotion socialization and vagal suppression for children's emotion regulation behaviors. Results suggest physiological regulation may serve as a buffer against nonsupportive emotion socialization. Copyright © 2011 Wiley Periodicals, Inc.

Validation and characterization of a novel method for selective vagal deafferentation of the gut.

PubMed

Diepenbroek, Charlene; Quinn, Danielle; Stephens, Ricky; Zollinger, Benjamin; Anderson, Seth; Pan, Annabelle; de Lartigue, Guillaume

2017-10-01

There is a lack of tools that selectively target vagal afferent neurons (VAN) innervating the gut. We use saporin (SAP), a potent neurotoxin, conjugated to the gastronintestinal (GI) hormone cholecystokinin (CCK-SAP) injected into the nodose ganglia (NG) of male Wistar rats to specifically ablate GI-VAN. We report that CCK-SAP ablates a subpopulation of VAN in culture. In vivo, CCK-SAP injection into the NG reduces VAN innervating the mucosal and muscular layers of the stomach and small intestine but not the colon, while leaving vagal efferent neurons intact. CCK-SAP abolishes feeding-induced c-Fos in the NTS, as well as satiation by CCK or glucagon like peptide-1 (GLP-1). CCK-SAP in the NG of mice also abolishes CCK-induced satiation. Therefore, we provide multiple lines of evidence that injection of CCK-SAP in NG is a novel selective vagal deafferentation technique of the upper GI tract that works in multiple vertebrate models. This method provides improved tissue specificity and superior separation of afferent and efferent signaling compared with vagotomy, capsaicin, and subdiaphragmatic deafferentation. NEW & NOTEWORTHY We develop a new method that allows targeted lesioning of vagal afferent neurons that innervate the upper GI tract while sparing vagal efferent neurons. This reliable approach provides superior tissue specificity and selectivity for vagal afferent over efferent targeting than traditional approaches. It can be used to address questions about the role of gut to brain signaling in physiological and pathophysiological conditions. Copyright © 2017 the American Physiological Society.

Parenting Stressors and Young Adolescents’ Depressive Symptoms: Does High Vagal Suppression Offer Protection?

PubMed Central

Fletcher, Anne C.; Buehler, Cheryl; Buchanan, Christy M.; Weymouth, Bridget B.

2017-01-01

Grounded in a dual-risk, biosocial perspective of developmental psychopathology, this study examined the role of higher vagal suppression in providing young adolescents protection from four parenting stressors. It was expected that lower vagal suppression would increase youth vulnerability to the deleterious effects of these parenting stressors. Depressive symptoms were examined as a central marker of socioemotional difficulties during early adolescence. The four parenting stressors examined were interparental hostility, maternal use of harsh discipline, maternal inconsistent discipline, and maternal psychological control. Participants were 68 young adolescents (Grade 6) and their mothers. Greater vagal suppression provided protection (i.e., lower depressive symptoms) from interparental hostility, harsh discipline, and maternal psychological control for boys but not for girls. PMID:27979628

The anabolic steroid nandrolone enhances motor and sensory functional recovery in rat median nerve repair with long interpositional nerve grafts.

PubMed

Ghizoni, Marcos Flávio; Bertelli, Jayme Augusto; Grala, Carolina Giesel; da Silva, Rosemeri Maurici

2013-01-01

Recovery from peripheral nerve repair is frequently incomplete. Hence drugs that enhance nerve regeneration are needed clinically. To study the effects of nandrolone decanoate in a model of deficient reinnervation in the rat. In 40 rats, a 40-mm segment of the left median nerve was removed and interposed between the stumps of a sectioned right median nerve. Starting 7 days after nerve grafting and continuing over a 6-month period, we administered nandrolone at a dose of 5 mg/kg/wk to half the rats (n = 20). All rats were assessed behaviorally for grasp function and nociceptive recovery for up to 6 months. At final assessment, reinnervated muscles were tested electrophysiologically and weighed. Results were compared between rats that had received versus not received nandrolone and versus 20 nongrafted controls. Rats in the nandrolone group recovered finger flexion faster. At 90 days postsurgery, they had recovered 42% of normal grasp strength versus just 11% in rats grafted but not treated with nandrolone. At 180 days, the average values for grasp strength recovery in the nandrolone and no-nandrolone groups were 40% and 33% of normal values for controls, respectively. At 180 days, finger flexor muscle twitch strength was 16% higher in treated versus nontreated rats. Thresholds for nociception were not detected in either group 90 days after nerve grafting. At 180 days, nociceptive thresholds were significantly lower in the nandrolone group. Nandrolone decanoate improved functional recovery in a model of deficient reinnervation.

At the heart of morality lies neuro-visceral integration: lower cardiac vagal tone predicts utilitarian moral judgment

PubMed Central

Kappes, Andreas; Rho, Yeojin; Van Bavel, Jay J.

2016-01-01

To not harm others is widely considered the most basic element of human morality. The aversion to harm others can be either rooted in the outcomes of an action (utilitarianism) or reactions to the action itself (deontology). We speculated that the human moral judgments rely on the integration of neural computations of harm and visceral reactions. The present research examined whether utilitarian or deontological aspects of moral judgment are associated with cardiac vagal tone, a physiological proxy for neuro-visceral integration. We investigated the relationship between cardiac vagal tone and moral judgment by using a mix of moral dilemmas, mathematical modeling and psychophysiological measures. An index of bipolar deontology-utilitarianism was correlated with resting heart rate variability (HRV)—an index of cardiac vagal tone—such that more utilitarian judgments were associated with lower HRV. Follow-up analyses using process dissociation, which independently quantifies utilitarian and deontological moral inclinations, provided further evidence that utilitarian (but not deontological) judgments were associated with lower HRV. Our results suggest that the functional integration of neural and visceral systems during moral judgments can restrict outcome-based, utilitarian moral preferences. Implications for theories of moral judgment are discussed. PMID:27317926

Large Intratemporal Facial Nerve Schwannoma without Facial Palsy: Surgical Strategy of Tumor Removal and Functional Reconstruction.

PubMed

Yetiser, Sertac

2018-06-08

 Three patients with large intratemporal facial schwannomas underwent tumor removal and facial nerve reconstruction with hypoglossal anastomosis. The surgical strategy for the cases was tailored to the location of the mass and its extension along the facial nerve.  To provide data on the different clinical aspects of facial nerve schwannoma, the appropriate planning for management, and the predictive outcomes of facial function.  Three patients with facial schwannomas (two men and one woman, ages 45, 36, and 52 years, respectively) who presented to the clinic between 2009 and 2015 were reviewed. They all had hearing loss but normal facial function. All patients were operated on with radical tumor removal via mastoidectomy and subtotal petrosectomy and simultaneous cranial nerve (CN) 7- CN 12 anastomosis.  Multiple segments of the facial nerve were involved ranging in size from 3 to 7 cm. In the follow-up period of 9 to 24 months, there was no tumor recurrence. Facial function was scored House-Brackmann grades II and III, but two patients are still in the process of functional recovery.  Conservative treatment with sparing of the nerve is considered in patients with small tumors. Excision of a large facial schwannoma with immediate hypoglossal nerve grafting as a primary procedure can provide satisfactory facial nerve function. One of the disadvantages of performing anastomosis is that there is not enough neural tissue just before the bifurcation of the main stump to provide neural suturing without tension because middle fossa extension of the facial schwannoma frequently involves the main facial nerve at the stylomastoid foramen. Reanimation should be processed with extensive backward mobilization of the hypoglossal nerve. Georg Thieme Verlag KG Stuttgart · New York.

Loss of neurotrophin-3 from smooth muscle disrupts vagal gastrointestinal afferent signaling and satiation

PubMed Central

Biddinger, Jessica E.; Baquet, Zachary C.; Jones, Kevin R.; McAdams, Jennifer

2013-01-01

A large proportion of vagal afferents are dependent on neurotrophin-3 (NT-3) for survival. NT-3 is expressed in developing gastrointestinal (GI) smooth muscle, a tissue densely innervated by vagal mechanoreceptors, and thus could regulate their survival. We genetically ablated NT-3 from developing GI smooth muscle and examined the pattern of loss of NT-3 expression in the GI tract and whether this loss altered vagal afferent signaling or feeding behavior. Meal-induced c-Fos activation was reduced in the solitary tract nucleus and area postrema in mice with a smooth muscle-specific NT-3 knockout (SM-NT-3KO) compared with controls, suggesting a decrease in vagal afferent signaling. Daily food intake and body weight of SM-NT-3KO mice and controls were similar. Meal pattern analysis revealed that mutants, however, had increases in average and total daily meal duration compared with controls. Mutants maintained normal meal size by decreasing eating rate compared with controls. Although microstructural analysis did not reveal a decrease in the rate of decay of eating in SM-NT-3KO mice, they ate continuously during the 30-min meal, whereas controls terminated feeding after 22 min. This led to a 74% increase in first daily meal size of SM-NT-3KO mice compared with controls. The increases in meal duration and first meal size of SM-NT-3KO mice are consistent with reduced satiation signaling by vagal afferents. This is the first demonstration of a role for GI NT-3 in short-term controls of feeding, most likely involving effects on development of vagal GI afferents that regulate satiation. PMID:24068045

Parenting stressors and young adolescents' depressive symptoms: Does high vagal suppression offer protection?

PubMed

Fletcher, Anne C; Buehler, Cheryl; Buchanan, Christy M; Weymouth, Bridget B

2017-03-01

Grounded in a dual-risk, biosocial perspective of developmental psychopathology, this study examined the role of higher vagal suppression in providing young adolescents protection from four parenting stressors. It was expected that lower vagal suppression would increase youth vulnerability to the deleterious effects of these parenting stressors. Depressive symptoms were examined as a central marker of socioemotional difficulties during early adolescence. The four parenting stressors examined were interparental hostility, maternal use of harsh discipline, maternal inconsistent discipline, and maternal psychological control. Participants were 68 young adolescents (Grade 6) and their mothers. Greater vagal suppression provided protection (i.e., lower depressive symptoms) from interparental hostility, harsh discipline, and maternal psychological control for boys but not for girls. Copyright © 2016 Elsevier Inc. All rights reserved.

Urban air pollution targets the dorsal vagal complex and dark chocolate offers neuroprotection.

PubMed

Villarreal-Calderon, Rafael; Torres-Jardón, Ricardo; Palacios-Moreno, Juan; Osnaya, Norma; Pérez-Guillé, Beatriz; Maronpot, Robert R; Reed, William; Zhu, Hongtu; Calderón-Garcidueñas, Lilian

2010-12-01

Mexico City (MC) residents exposed to fine particulate matter and endotoxin exhibit inflammation of the olfactory bulb, substantia nigra, and vagus nerve. The goal of this study was to model these endpoints in mice and examine the neuroprotective effects of chocolate. Mice exposed to MC air received no treatment or oral dark chocolate and were compared to clean-air mice either untreated or treated intraperitoneally with endotoxin. Cyclooxygenase-2 (COX-2), interleukin 1 beta (IL-1β), and CD14 messenger RNA (mRNA) were quantified after 4, 8, and 16 months of exposure in target brain regions. After 16 months of exposure, the dorsal vagal complex (DVC) exhibited significant inflammation in endotoxin-treated and MC mice (COX-2 and IL-1β P<.001). Mexico City mice had olfactory bulb upregulation of CD14 (P=.002) and significant DVC imbalance in genes for antioxidant defenses, apoptosis, and neurodegeneration. These findings demonstrate sustained DVC inflammation in mice exposed to MC air, which is mitigated by chocolate administration. © The Author(s) 2010

The First Experience of Triple Nerve Transfer in Proximal Radial Nerve Palsy.

PubMed

Emamhadi, Mohammadreza; Andalib, Sasan

2018-01-01

Injury to distal portion of posterior cord of brachial plexus leads to palsy of radial and axillary nerves. Symptoms are usually motor deficits of the deltoid muscle; triceps brachii muscle; and extensor muscles of the wrist, thumb, and fingers. Tendon transfers, nerve grafts, and nerve transfers are options for surgical treatment of proximal radial nerve palsy to restore some motor functions. Tendon transfer is painful, requires a long immobilization, and decreases donor muscle strength; nevertheless, nerve transfer produces promising outcomes. We present a patient with proximal radial nerve palsy following a blunt injury undergoing triple nerve transfer. The patient was involved in a motorcycle accident with complete palsy of the radial and axillary nerves. After 6 months, on admission, he showed spontaneous recovery of axillary nerve palsy, but radial nerve palsy remained. We performed triple nerve transfer, fascicle of ulnar nerve to long head of the triceps branch of radial nerve, flexor digitorum superficialis branch of median nerve to extensor carpi radialis brevis branch of radial nerve, and flexor carpi radialis branch of median nerve to posterior interosseous nerve, for restoration of elbow, wrist, and finger extensions, respectively. Our experience confirmed functional elbow, wrist, and finger extensions in the patient. Triple nerve transfer restores functions of the upper limb in patients with debilitating radial nerve palsy after blunt injuries. Copyright © 2017 Elsevier Inc. All rights reserved.

Raman spectroscopic detection of peripheral nerves towards nerve-sparing surgery

NASA Astrophysics Data System (ADS)

Minamikawa, Takeo; Harada, Yoshinori; Takamatsu, Tetsuro

2017-02-01

The peripheral nervous system plays an important role in motility, sensory, and autonomic functions of the human body. Preservation of peripheral nerves in surgery, namely nerve-sparing surgery, is now promising technique to avoid functional deficits of the limbs and organs following surgery as an aspect of the improvement of quality of life of patients. Detection of peripheral nerves including myelinated and unmyelinated nerves is required for the nerve-sparing surgery; however, conventional nerve identification scheme is sometimes difficult to identify peripheral nerves due to similarity of shape and color to non-nerve tissues or its limited application to only motor peripheral nerves. To overcome these issues, we proposed a label-free detection technique of peripheral nerves by means of Raman spectroscopy. We found several fingerprints of peripheral myelinated and unmyelinated nerves by employing a modified principal component analysis of typical spectra including myelinated nerve, unmyelinated nerve, and adjacent tissues. We finally realized the sensitivity of 94.2% and the selectivity of 92.0% for peripheral nerves including myelinated and unmyelinated nerves against adjacent tissues. Although further development of an intraoperative Raman spectroscopy system is required for clinical use, our proposed approach will serve as a unique and powerful tool for peripheral nerve detection for nerve-sparing surgery in the future.

Effects of Eucommia leaf extracts on autonomic nerves, body temperature, lipolysis, food intake, and body weight.

PubMed

Horii, Yuko; Tanida, Mamoru; Shen, Jiao; Hirata, Tetsuya; Kawamura, Naomi; Wada, Atsunori; Nagai, Katsuya

2010-08-02

Eucommia ulmoides Oliver leaf extracts (ELE) have been shown to exert a hypolipidemic effect in hamsters. Therefore, it was hypothesized that ELE might affect lipid metabolism via changes in autonomic nerve activities and causes changes in thermogenesis and body weight. We examined this hypothesis, and found that intraduodenal (ID) injection of ELE elevated epididymal white adipose tissue sympathetic nerve activity (WAT-SNA) and interscapular brown adipose tissue sympathetic nerve activity (BAT-SNA) in urethane-anesthetized rats and elevated the plasma concentration of free fatty acids (FFA) (a marker of lipolysis) and body temperature (BT) (a marker of thermogenesis) in conscious rats. Furthermore, it was observed that ID administration of ELE decreased gastric vagal nerve activity (GVNA) in urethane-anesthetized rats, and that ELE given as food reduced food intake, body and abdominal adipose tissue weights and decreased plasma triglyceride level. These findings suggest that ELE stimulates lipolysis and thermogenesis through elevations in WAT-SNA and BAT-SNA, respectively, suppresses appetite by inhibiting the activities of the parasympathetic nerves innervating the gastrointestinal tract, including GVNA, and decreases the amount of abdominal fat and body weight via these changes. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

Misdirection of Regenerating Axons and Functional Recovery Following Sciatic Nerve Injury in Rats

PubMed Central

Hamilton, Shirley K.; Hinkle, Marcus L.; Nicolini, Jennifer; Rambo, Lindsay N.; Rexwinkle, April M.; Rose, Sam J.; Sabatier, Manning J.; Backus, Deborah; English, Arthur W.

2013-01-01

Poor functional recovery found after peripheral nerve injury has been attributed to the misdirection of regenerating axons to reinnervate functionally inappropriate muscles. We applied brief electrical stimulation (ES) to the common fibular (CF) but not the tibial (Tib) nerve just prior to transection and repair of the entire rat sciatic nerve, to attempt to influence the misdirection of its regenerating axons. The specificity with which regenerating axons reinnervated appropriate targets was evaluated physiologically using compound muscle action potentials (M responses) evoked from stimulation of the two nerve branches above the injury site. Functional recovery was assayed using the timing of electromyography (EMG) activity recorded from the tibialis anterior (TA) and soleus (Sol) muscles during treadmill locomotion and kinematic analysis of hindlimb locomotor movements. Selective ES of the CF nerve resulted in restored M-responses at earlier times than in unstimulated controls in both TA and Sol muscles. Stimulated CF axons reinnervated inappropriate targets to a greater extent than unstimulated Tib axons. During locomotion, functional antagonist muscles, TA and Sol, were coactivated both in stimulated rats and in unstimulated but injured rats. Hindlimb kinematics in stimulated rats were comparable to untreated rats, but significantly different from intact controls. Selective ES promotes enhanced axon regeneration but does so with decreased fidelity of muscle reinnervation. Functional recovery is neither improved nor degraded, suggesting that compensatory changes in the outputs of the spinal circuits driving locomotion may occur irrespective of the extent of misdirection of regenerating axons in the periphery. PMID:21120925

Transplantation of embryonic stem cells improves nerve repair and functional recovery after severe sciatic nerve axotomy in rats.

PubMed

Cui, Lin; Jiang, Jun; Wei, Ling; Zhou, Xin; Fraser, Jamie L; Snider, B Joy; Yu, Shan Ping

2008-05-01

Extensive research has focused on transplantation of pluripotent stem cells for the treatment of central nervous system disorders, the therapeutic potential of stem cell therapy for injured peripheral nerves is largely unknown. We used a rat sciatic nerve transection model to test the ability of implanted embryonic stem (ES) cell-derived neural progenitor cells (ES-NPCs) in promoting repair of a severely injured peripheral nerve. Mouse ES cells were neurally induced in vitro; enhanced expression and/or secretion of growth factors were detected in differentiating ES cells. One hour after removal of a 1-cm segment of the left sciatic nerve, ES-NPCs were implanted into the gap between the nerve stumps with the surrounding epineurium as a natural conduit. The transplantation resulted in substantial axonal regrowth and nerve repair, which were not seen in culture medium controls. One to 3 months after axotomy, co-immunostaining with the mouse neural cell membrane specific antibody M2/M6 and the Schwann cell marker S100 suggested that transplanted ES-NPCs had survived and differentiated into myelinating cells. Regenerated axons were myelinated and showed a uniform connection between proximal and distal stumps. Nerve stumps had near normal diameter with longitudinally oriented, densely packed Schwann cell-like phenotype. Fluoro-Gold retrogradely labeled neurons were found in the spinal cord (T12-13) and DRG (L4-L6), suggesting reconnection of axons across the transection. Electrophysiological recordings showed functional activity recovered across the injury gap. These data suggest that transplanted neurally induced ES cells differentiate into myelin-forming cells and provide a potential therapy for severely injured peripheral nerves.

Mothers’ Responses to Children’s Negative Emotions and Child Emotion Regulation: The Moderating Role of Vagal Suppression

PubMed Central

Perry, Nicole B.; Calkins, Susan D.; Nelson, Jackie A.; Leerkes, Esther M.; Marcovitch, Stuart

2011-01-01

The current study examined the moderating effect of children’s cardiac vagal suppression on the association between maternal socialization of negative emotions (supportive and non-supportive responses) and children’s emotion regulation behaviors. One hundred and ninety-seven 4-year-olds and their mothers participated. Mothers reported on their reactions to children’s negative emotions and children’s regulatory behaviors. Observed distraction, an adaptive self-regulatory strategy, and vagal suppression were assessed during a laboratory task designed to elicit frustration. Results indicated that children’s vagal suppression moderated the association between mothers’ non-supportive emotion socialization and children’s emotion regulation behaviors such that non-supportive reactions to negative emotions predicted lower observed distraction and lower reported emotion regulation behaviors when children displayed lower levels of vagal suppression. No interaction was found between supportive maternal emotion socialization and vagal suppression for children’s emotion regulation behaviors. Results suggest physiological regulation may serve as a buffer against non-supportive emotion socialization. PMID:22072217

[Blood-nerve barrier and peripheral nerve regeneration].

PubMed

Kanda, Takashi

2013-01-01

Blood-nerve barrier (BNB) restricts the movement of soluble mediators and leukocytes from the blood contents to the peripheral nervous system (PNS) parenchyma and thus maintains the endoneurial homeostasis. However, it interferes the supply of various neurotrophic factors from the blood constituents and stops the drainage of toxic substances out of the PNS parenchyma, resulting in the inhibition of peripheral nerve regeneration. If the manipulation of BNB function is possible, regeneration of peripheral nerve may be facilitated via the alteration of peripheral nerve microenvironment and ample supply of neurotrophic substances. A possible method to manipulate the BNB for therapeutic purposes is to modify the endothelial function using siRNAs, oligonucleotides and virus vectors. Another possible method is to modify BNB pericytes: small hydrophobic substances that can reach the pericyte membrane through the endothelial monolayer and strengthen the pericytic activity, including the release of various cytokines/chemokines that influence endothelial function, may also be useful as drug candidates to control the BNB function.

Glucose-dependent trafficking of 5-HT3 receptors in rat gastrointestinal vagal afferent neurons

PubMed Central

Babic, Tanja; Troy, Amanda E; Fortna, Samuel R; Browning, Kirsteen N

2012-01-01

Background Intestinal glucose induces gastric relaxation via vagally mediated sensory-motor reflexes. Glucose can alter the activity of gastrointestinal (GI) vagal afferent (sensory) neurons directly, via closure of ATP-sensitive potassium channels, as well as indirectly, via the release of 5-hydroxytryptamine (5-HT) from mucosal enteroendocrine cells. We hypothesized that glucose may also be able to modulate the ability of GI vagal afferent neurons to respond to the released 5-HT, via regulation of neuronal 5-HT3 receptors. Methods Whole cell patch clamp recordings were made from acutely dissociated GI-projecting vagal afferent neurons exposed to equiosmolar Krebs’ solution containing different concentrations of D-glucose (1.25–20mM) and the response to picospritz application of 5-HT assessed. The distribution of 5-HT3 receptors in neurons exposed to different glucose concentrations was also assessed immunohistochemically. Key Results Increasing or decreasing extracellular D-glucose concentration increased or decreased, respectively, the 5-HT-induced inward current as well as the proportion of 5-HT3 receptors associated with the neuronal membrane. These responses were blocked by the Golgi-disrupting agent Brefeldin-A (5µM) suggesting involvement of a protein trafficking pathway. Furthermore, L-glucose did not mimic the response of D-glucose implying that metabolic events downstream of neuronal glucose uptake are required in order to observe the modulation of 5-HT3 receptor mediated responses. Conclusions & Inferences These results suggest that, in addition to inducing the release of 5-HT from enterochromaffin cells, glucose may also increase the ability of GI vagal sensory neurons to respond to the released 5-HT, providing a means by which the vagal afferent signal can be amplified or prolonged. PMID:22845622

Monitoring of recurrent and superior laryngeal nerve function using an Airwayscope™ during thyroid surgery.

PubMed

Ijichi, Kei; Sasano, Hiroshi; Harima, Megumi; Murakami, Shingo

2017-10-01

In thyroid surgery, intraoperative identification and preservation of the recurrent laryngeal nerve (RLN) and superior laryngeal nerve external branch (SLNEB) are crucial. Several reports have proposed that electromyography (EMG) monitoring is an acceptable adjunct for identification and preservation of the RLN. However, a limited number of hospitals have access to an EMG monitoring system. Therefore, the development of another viable monitoring method is required. The aim of the present study was to design a new RLN and SLNEB monitoring method combining an Airwayscope™ (AWS) and a facial nerve stimulator. The facial nerve-stimulating electrode stimulates the RLN or SLNEB, so that the movement of the vocal cord may be observed with an AWS. This monitoring method was performed on 10 patients with a thyroid tumor. In all the cases, RLN and SLNEB were identified and vocal cord function was preserved. All the patients exhibited normal vocal cord function following surgery. Thus, the new RLN and SLNEB monitoring method using an AWS and a facial nerve stimulator is useful in thyroid surgery, and this method may be used as a reliable and available alternative to EMG monitoring to ensure the normal function of the vocal cord.

Dynamic analysis of patterns of renal sympathetic nerve activity: implications for renal function.

PubMed

DiBona, Gerald F

2005-03-01

Methods of dynamic analysis are used to provide additional understanding of the renal sympathetic neural control of renal function. The concept of functionally specific subgroups of renal sympathetic nerve fibres conveying information encoded in the frequency domain is presented. Analog pulse modulation and pseudorandom binary sequence stimulation patterns are used for the determination of renal vascular frequency response. Transfer function analysis is used to determine the effects of non-renal vasoconstrictor and vasoconstrictor intensities of renal sympathetic nerve activity on dynamic autoregulation of renal blood flow.

L-carnitine alleviates sciatic nerve crush injury in rats: functional and electron microscopy assessments

PubMed Central

Avsar, Ümmü Zeynep; Avsar, Umit; Aydin, Ali; Yayla, Muhammed; Ozturkkaragoz, Berna; Un, Harun; Saritemur, Murat; Mercantepe, Tolga

2014-01-01

Several studies have demonstrated that L-carnitine exhibits neuroprotective effects on injured sciatic nerve of rats with diabetes mellitus. It is hypothesized that L-carnitine exhibits neuroprotective effects on injured sciatic nerve of rats. Rat sciatic nerve was crush injured by a forceps and exhibited degenerative changes. After intragastric administration of 50 and 100 mg/kg L-carnitine for 30 days, axon area, myelin sheath area, axon diameter, myelin sheath diameter, and numerical density of the myelinated axons of injured sciatic nerve were similar to normal, and the function of injured sciatic nerve also improved significantly. These findings suggest that L-carnitine exhibits neuroprotective effects on sciatic nerve crush injury in rats. PMID:25206754

Autonomic nervous system function in young children with functional abdominal pain or irritable bowel syndrome.

PubMed

Jarrett, Monica; Heitkemper, Margaret; Czyzewski, Danita; Zeltzer, Lonnie; Shulman, Robert J

2012-05-01

Adults with irritable bowel syndrome (IBS) have been reported to have alterations in autonomic nervous system function as measured by vagal activity via heart rate variability. Whether the same is true for children is unknown. We compared young children 7 to 10 years of age with functional abdominal pain (FAP) or IBS to healthy children (HC) and explored the relationship of vagal activity and sympathovagal balance to psychological distress and stool type. Children completed questionnaires, kept a 2-week pain/stool diary, and wore a 24-hour Holter monitor to assess vagal activity. Group comparisons on vagal activity were controlled for age and body mass index. Indicators of vagal activity and sympathovagal balance did not differ between FAP/IBS children (70 girls, 30 boys) and HC (44 girls, 18 boys). Psychological distress measures were generally higher in FAP/IBS than HC, primarily in girls. Exploratory analyses suggest a potential negative correlation between vagal activity and psychological distress in FAP/IBS girls but not boys. In contrast to reports in women, no differences were found in vagal activity between FAP/IBS and HC. Preliminary findings suggest that in girls with FAP/IBS there is an inverse relationship between vagal activity and psychological distress. The results from this study suggest a possible relationship between emotional state and vagal activity in prepubertal girls (but not boys) with FAP/IBS. Age and/or duration of symptoms may explain our contrasting findings versus adults with IBS. Copyright © 2012 American Pain Society. Published by Elsevier Inc. All rights reserved.

Microsurgical reconstruction of large nerve defects using autologous nerve grafts.

PubMed

Daoutis, N K; Gerostathopoulos, N E; Efstathopoulos, D G; Misitizis, D P; Bouchlis, G N; Anagnostou, S K

1994-01-01

Between 1986 and 1993, 643 patients with peripheral nerve trauma were treated in our clinic. Primary neurorraphy was performed in 431 of these patients and nerve grafting in 212 patients. We present the functional results after nerve grafting in 93 patients with large nerve defects who were followed for more than 2 years. Evaluation of function was based on the Medical Research Council (MRC) classification for motor and sensory recovery. Factors affecting functional outcome, such as age of the patient, denervation time, length of the defect, and level of the injury were noted. Good results according to the MRC classification were obtained in the majority of cases, although function remained less than that of the uninjured side.

Supinator to ulnar nerve transfer via in situ anterior interosseous nerve bridge to restore intrinsic muscle function in combined proximal median and ulnar nerve injury: a novel cadaveric study.

PubMed

Namazi, Hamid; HajiVandi, Shahin

2017-05-01

In cases of high ulnar nerve palsy, result of nerve repair in term of intrinsic muscle recovery is unsatisfactory. Distal nerve transfer can diminish the regeneration time and improve the results. But, there was no perfect distal nerve transfer for restoring intrinsic hand function in combined proximal median and ulnar nerve injuries. This cadaveric study aims to evaluate the possibility and feasibility of supinator nerve transfer to motor branch of ulnar nerve (MUN). Ten cadaveric upper limbs dissected to identify the location of the supinator branch, anterior interosseous nerve (AIN), and MUN. The AIN was cut from its origin and transferred to the supinator branches. Also, the AIN was distally cut and transferred to the MUN. After nerve coaptation, surface area, fascicle count, and axon number were determined by histologic methods. In all limbs, the proximal and distal stumps of AIN reached the supinator branch and the MUN without tension, respectively. The mean of axon number in the supinator, proximal stump of AIN, distal stump of AIN and MUN branches were 32,426, 45,542, 25,288, and 35,426, respectively. This study showed that transfer of the supinator branches to the MUN is possible via the in situ AIN bridge. The axon count data showed a favorable match between the supinator branches, AIN, and MUN. Therefore, it is suggested that this technique can be useful for patients with combined high median and ulnar nerve injuries. Copyright © 2016 Elsevier Inc. All rights reserved.

CORRELATION BETWEEN MARKERS OF PERIPHERAL NERVE FUNCTION AND STRUCTURE IN TYPE 1 DIABETES.

PubMed

Borire, Adeniyi A; Issar, Tushar; Kwai, Natalie C; Visser, Leo H; Simon, Neil G; Poynten, Ann M; Kiernan, Matthew C; Krishnan, Arun V

2018-06-01

Clinical and experimental studies in patients with type 1 and type 2 diabetes have demonstrated changes in ion channel function and nerve structure. In this study, we investigated the relationship between axonal dysfunction and morphological change in diabetic polyneuropathy using neuromuscular ultrasound and nerve excitability techniques. We also explored possible differences in this relationship between type 1 and type 2 diabetes. Nerve ultrasound and corresponding motor excitability studies were undertaken in 110 diabetes patients (50 type 1;60 type 2) and 60 age-matched controls (30 for each group). Neuropathy severity was assessed using Total Neuropathy Score. Median and tibial nerve cross-sectional areas were measured at non-entrapment sites using high resolution linear probe. Median and tibial nerve cross-sectional areas were significantly higher in diabetes patients compared to controls: Type1 (Median=7.6±0.2mm 2 vs. 6.3±0.1mm 2 ; Tibial=14.5±0.7mm 2 vs. 10.8±0.3mm 2 ,p<0.05) and Type 2 (Median=9.1±0.3mm 2 vs. 7.2±0.1mm 2 ; Tibial=18.5±1.0mm 2 vs. 12.8±0.5mm 2 ,p<0.05). In the type 1 cohort, significant correlations were found between nerve cross-sectional area and excitability parameters including resting current-threshold slope (Median: r=0.523,p<0.0001; Tibial: r=-0.571,p=0.004) and depolarizing threshold electrotonus at 90-100ms (Median: 0.424,p<0.01; Tibial: r=0.435,p=0.030). In contrast, there was no relationship between excitability values and nerve cross-sectional area in the type 2 cohort. This study has identified correlation between markers of axonal membrane function and structural abnormalities in peripheral nerves of type 1 diabetes patients. The differential relationship in nerve function and structure between Type 1 and Type 2 diabetes provides clinical evidence that different pathophysiological mechanisms underlie the development of neuropathy in these patient groups. This article is protected by copyright. All rights reserved.

Methods to evaluate functional nerve recovery in adult rats: walking track analysis, video analysis and the withdrawal reflex.

PubMed

Dijkstra, J R; Meek, M F; Robinson, P H; Gramsbergen, A

2000-03-15

The aim of this study was to compare different methods for the evaluation of functional nerve recovery. Three groups of adult male Wistar rats were studied. In group A, a 12-mm gap between nerve ends was bridged by an autologous nerve graft; in rats of group B we performed a crush lesion of the sciatic nerve and group C consisted of non-operated control rats. The withdrawal reflex, elicited by an electric stimulus, was used to evaluate the recovery of sensory nerve function. To investigate motor nerve recovery we analyzed the walking pattern. Three different methods were used to obtain data for footprint analysis: photographic paper with thickened film developer on the paws, normal white paper with finger paint, and video recordings. The footprints were used to calculate the sciatic function index (SFI). From the video recordings, we also analyzed stepcycles. The withdrawal reflex is a convenient and reproducible test for the evaluation of global sensory nerve recovery. Recording walking movements on video and the analysis of footplacing is a perfect although time-consuming method for the evaluation of functional aspects of motor nerve recovery.

At the heart of morality lies neuro-visceral integration: lower cardiac vagal tone predicts utilitarian moral judgment.

PubMed

Park, Gewnhi; Kappes, Andreas; Rho, Yeojin; Van Bavel, Jay J

2016-10-01

To not harm others is widely considered the most basic element of human morality. The aversion to harm others can be either rooted in the outcomes of an action (utilitarianism) or reactions to the action itself (deontology). We speculated that the human moral judgments rely on the integration of neural computations of harm and visceral reactions. The present research examined whether utilitarian or deontological aspects of moral judgment are associated with cardiac vagal tone, a physiological proxy for neuro-visceral integration. We investigated the relationship between cardiac vagal tone and moral judgment by using a mix of moral dilemmas, mathematical modeling and psychophysiological measures. An index of bipolar deontology-utilitarianism was correlated with resting heart rate variability (HRV)-an index of cardiac vagal tone-such that more utilitarian judgments were associated with lower HRV. Follow-up analyses using process dissociation, which independently quantifies utilitarian and deontological moral inclinations, provided further evidence that utilitarian (but not deontological) judgments were associated with lower HRV. Our results suggest that the functional integration of neural and visceral systems during moral judgments can restrict outcome-based, utilitarian moral preferences. Implications for theories of moral judgment are discussed. © The Author (2016). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

Relationship between sensorimotor peripheral nerve function and indicators of cardiovascular autonomic function in older adults from the Health, Aging and Body Composition Study.

PubMed

Lange-Maia, Brittney S; Newman, Anne B; Jakicic, John M; Cauley, Jane A; Boudreau, Robert M; Schwartz, Ann V; Simonsick, Eleanor M; Satterfield, Suzanne; Vinik, Aaron I; Zivkovic, Sasa; Harris, Tamara B; Strotmeyer, Elsa S

2017-10-01

Age-related peripheral nervous system (PNS) impairments are highly prevalent in older adults. Although sensorimotor and cardiovascular autonomic function have been shown to be related in persons with diabetes, the nature of the relationship in general community-dwelling older adult populations is unknown. Health, Aging and Body Composition participants (n=2399, age=76.5±2.9years, 52% women, 38% black) underwent peripheral nerve testing at the 2000/01 clinic visit. Nerve conduction amplitude and velocity were measured at the peroneal motor nerve. Sensory nerve function was assessed with vibration detection threshold and monofilament (1.4-g/10-g) testing at the big toe. Symptoms of lower-extremity peripheral neuropathy were collected by self-report. Cardiovascular autonomic function indicators included postural hypotension, resting heart rate (HR), as well as HR response to and recovery from submaximal exercise testing (400m walk). Multivariable modeling adjusted for demographic/lifestyle factors, medication use and comorbid conditions. In fully adjusted models, poor motor nerve conduction velocity (<40m/s) was associated with greater odds of postural hypotension, (OR=1.6, 95% CI: 1.0-2.5), while poor motor amplitude (<1mV) was associated with 2.3beats/min (p=0.003) higher resting HR. No associations were observed between sensory nerve function or symptoms of peripheral neuropathy and indicators of cardiovascular autonomic function. Motor nerve function and indicators of cardiovascular autonomic function remained significantly related even after considering many potentially shared risk factors. Future studies should investigate common underlying processes for developing multiple PNS impairments in older adults. Copyright © 2017 Elsevier Inc. All rights reserved.

Effects of smartphone overuse on hand function, pinch strength, and the median nerve.

PubMed

İnal, Esra Erkol; Demİrcİ, kadİr; Çetİntürk, Azİze; Akgönül, Mehmet; Savaş, Serpİl

2015-08-01

In this study we investigated the flexor pollicis longus (FPL) tendon and median nerve in smartphone users by ultrasonography to assess the effects of smartphone addiction on the clinical and functional status of the hands. One hundred two students were divided into 3 groups: non-users, and high or low smartphone users. Smartphone Addiction Scale (SAS) scores and grip and pinch strengths were recorded. Pain in thumb movement and rest and hand function were evaluated on the visual analog scale (VAS) and the Duruöz Hand Index (DHI), respectively. The cross-sectional areas (CSAs) of the median nerve and the FPL tendon were calculated bilaterally using ultrasonography. Significantly higher median nerve CSAs were observed in the dominant hands of the high smartphone users than in the non-dominant hands (P<0.001). SAS scores correlated with VAS pain for movement and rest, DHI scores, and pinch strength (P<0.05; r=0.345, 0.272, 0.245, and 0.281, respectively). Smartphone overuse enlarges the median nerve, causes pain in the thumb, and decreases pinch strength and hand functions. © 2015 Wiley Periodicals, Inc.

Nerve Transfer Versus Nerve Graft for Reconstruction of High Ulnar Nerve Injuries.

PubMed

Sallam, Asser A; El-Deeb, Mohamed S; Imam, Mohamed A

2017-04-01

To assess the efficacy of nerve transfer versus nerve grafting in restoring motor and sensory hand function in patients with complete, isolated high ulnar nerve injuries. A retrospective chart review was performed, at a minimum 2 years of follow-up, of 52 patients suffering complete, isolated high ulnar nerve injury between January 2006 and June 2013 in one specialized hand surgery unit. Twenty-four patients underwent motor and sensory nerve transfers (NT group). Twenty-eight patients underwent sural nerve grafting (NG group). Motor recovery, return of sensibility and complications were examined as outcome measures. The Medical Research Council scale was applied to evaluate sensory and motor recovery. Grip and pinch strengths of the hand were measured. Twenty of 24 patients (83.33%) in the NT group regained M3 grade or greater for the adductor pollicis, the abductor digiti minimi, and the medial 2 lumbricals and interossei, compared with only 16 of 28 patients (57.14%) in the NG group. Means for percentage recovery of grip strengths compared with the other healthy hand were significantly higher for the NT group than the NG group. Sensory recovery of S3 or greater was achieved in more than half of each group with no significant difference between groups. Nerve transfer is favored over nerve grafting in managing high ulnar nerve injuries because of better improvement of motor power and better restoration of grip functions of the hand. Therapeutic IV. Copyright © 2017 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Treatment of peroneal nerve injuries with simultaneous tendon transfer and nerve exploration.

PubMed

Ho, Bryant; Khan, Zubair; Switaj, Paul J; Ochenjele, George; Fuchs, Daniel; Dahl, William; Cederna, Paul; Kung, Theodore A; Kadakia, Anish R

2014-08-06

Common peroneal nerve palsy leading to foot drop is difficult to manage and has historically been treated with extended bracing with expectant waiting for return of nerve function. Peroneal nerve exploration has traditionally been avoided except in cases of known traumatic or iatrogenic injury, with tendon transfers being performed in a delayed fashion after exhausting conservative treatment. We present a new strategy for management of foot drop with nerve exploration and concomitant tendon transfer. We retrospectively reviewed a series of 12 patients with peroneal nerve palsies that were treated with tendon transfer from 2005 to 2011. Of these patients, seven were treated with simultaneous peroneal nerve exploration and repair at the time of tendon transfer. Patients with both nerve repair and tendon transfer had superior functional results with active dorsiflexion in all patients, compared to dorsiflexion in 40% of patients treated with tendon transfers alone. Additionally, 57% of patients treated with nerve repair and tendon transfer were able to achieve enough function to return to running, compared to 20% in patients with tendon transfer alone. No patient had full return of native motor function resulting in excessive dorsiflexion strength. The results of our limited case series for this rare condition indicate that simultaneous nerve repair and tendon transfer showed no detrimental results and may provide improved function over tendon transfer alone.

Influence of neural monitoring during thyroid surgery on nerve integrity and postoperative vocal function.

PubMed

Engelsman, A F; Warhurst, S; Fraser, S; Novakovic, D; Sidhu, S B

2018-06-01

Integrity of the recurrent laryngeal nerve (RLN) and the external branch of the superior laryngeal nerve (EBSLN) can be checked by intraoperative nerve monitoring (IONM) after visualization. The aim of this study was to determine the prevalence and nature of voice dysfunction following thyroid surgery with routine IONM. Thyroidectomies were performed with routine division of strap muscles and nerve monitoring to confirm integrity of the RLN and EBSLN following dissection. Patients were assessed for vocal function before surgery and at 1 and 3 months after operation. Assessment included use of the Voice Handicap Index (VHI) 10, maximum phonation time, fundamental frequency, pitch range, harmonic to noise ratio, cepstral peak prominence and smoothed cepstral peak prominence. A total of 172 nerves at risk were analysed in 102 consecutive patients undergoing elective thyroid surgery. In 23·3 per cent of EBSLNs and 0·6 per cent of RLNs nerve identification required the assistance of IONM in addition to visualization. Nerve integrity was confirmed during surgery for 98·8 per cent of EBSLNs and 98·3 per cent of RLNs. There were no differences between preoperative and postoperative VHI-10 scores. Acoustic voice assessment showed small changes in maximum phonation time at 1 and 3 months after surgery. Where there is routine division of strap muscles, thyroidectomy using nerve monitoring confirmation of RLN and EBSLN function following dissection results in no clinically significant voice change.

Role of vagal afferents in the ventilatory response to naloxone during loaded breathing in the rabbit.

PubMed

Delpierre, S; Pugnat, C; Duté, N; Jammes, Y

1995-02-15

It was previously shown that inspiratory resistive loading (IRL) increases the cerebrospinal fluid (CSF) level of beta endorphin in awake goats, and also that the slower ventilation induced by injection of this substance into the CSF of anesthetized dogs is suppressed after vagotomy. In the present study, performed on anesthetized rabbits, we evaluated the part played by vagal afferents in the ventilatory response to IRL after opioid receptor blockade by naloxone. During unloaded breathing, naloxone injection did not modify baseline ventilation. Conversely, naloxone partially reversed IRL-induced hypoventilation through an increase in respiratory rate. This effect was abolished after either vagotomy or cold blockade of large vagal fibers, but it persisted after procaine blockade of thin vagal fibers. These results suggest that pulmonary stretch receptors, which are connected to some large vagal afferent fibers, would play a major role in the ventilatory response to IRL under opioid receptor inhibition.

Electroacupuncture improves burn-induced impairment in gastric motility mediated via the vagal mechanism in rats.

PubMed

Song, J; Yin, J; Sallam, H S; Bai, T; Chen, Y; Chen, J D Z

2013-10-01

Delayed gastric emptying (GE) is common in patients with severe burns. This study was designed to investigate effects and mechanisms of electroacupuncture (EA) on gastric motility in rats with burns. Male rats (intact and vagotomized) were implanted with gastric electrodes, chest and abdominal wall electrodes for investigating the effects of EA at ST-36 (stomach-36 or Zusanli) on GE, gastric slow waves, autonomic functions, and plasma interleukin 6 (IL-6) 6 and 24 h post severe burns. (i) Burn delayed GE (P < 0.001). Electroacupuncture improved GE 6 and 24 h post burn (P < 0.001). Vagotomy blocked the EA effect on GE. (ii) Electroacupuncture improved burn-induced gastric dysrhythmia. The percentage of normal slow waves was increased with EA 6 and 24 h post burn (P = 0.02). (iii) Electroacupuncture increased vagal activity assessed by the spectral analysis of heart rate variability (HRV). The high-frequency component reflecting vagal component was increased with EA 6 (P = 0.004) and 24 h post burn (P = 0.03, vs sham-EA). (iv) Electroacupuncture attenuated burn-induced increase in plasma IL-6 at both 6 (P = 0.03) and 24 h post burn (P = 0.003). Electroacupuncture at ST-36 improves gastric dysrhythmia and accelerates GE in rats with burns. The improvement seems to be mediated via the vagal pathway involving the inflammatory cytokine IL-6. © 2013 John Wiley & Sons Ltd.

Functional MRI Detection of Hemodynamic Response of Repeated Median Nerve Stimulation

PubMed Central

Ai, Leo; Oya, Hiroyuki; Howard, Matthew; Xiong, Jinhu

2012-01-01

Median nerve stimulation is a commonly used technique in the clinical setting to determine areas of neuronal function in the brain. Neuronal activity of repeated median nerve stimulation is well studied. The cerebral hemodynamic response of the stimulation, on the other hand, is not very clear. In this study, we investigate how cerebral hemodynamics behaves over time using the same repeated median nerve stimulation. Ten subjects received constant repeated electrical stimulation to the right median nerve. Each subject had fMRI scans while receiving said stimulations for seven runs. Our results show that the BOLD signal significantly decreases across each run. Significant BOLD signal decreases can also be seen within runs. These results are consistent with studies that have studied the hemodynamic habituation effect with other forms of stimulation. However, the results do not completely agree with the findings of studies where evoked potentials were examined. Thus, further inquiry of how evoked potentials and cerebral hemodynamics are coupled when using constant stimulations is needed. PMID:23228312

Sluggish vagal brake reactivity to physical exercise challenge in children with selective mutism.

PubMed

Heilman, Keri J; Connolly, Sucheta D; Padilla, Wendy O; Wrzosek, Marika I; Graczyk, Patricia A; Porges, Stephen W

2012-02-01

Cardiovascular response patterns to laboratory-based social and physical exercise challenges were evaluated in 69 children and adolescents, 20 with selective mutism (SM), to identify possible neurophysiological mechanisms that may mediate the behavioral features of SM. Results suggest that SM is associated with a dampened response of the vagal brake to physical exercise that is manifested as reduced reactivity in heart rate and respiration. Polyvagal theory proposes that the regulation of the vagal brake is a neurophysiological component of an integrated social engagement system that includes the neural regulation of the laryngeal and pharyngeal muscles. Within this theoretical framework, sluggish vagal brake reactivity may parallel an inability to recruit efficiently the structures involved in speech. Thus, the findings suggest that dampened autonomic reactivity during mobilization behaviors may be a biomarker of SM that can be assessed independent of the social stimuli that elicit mutism.

Distinct projection targets define subpopulations of mouse brainstem vagal neurons that express the autism-associated MET receptor tyrosine kinase.

PubMed

Kamitakahara, Anna; Wu, Hsiao-Huei; Levitt, Pat

2017-12-15

Detailed anatomical tracing and mapping of the viscerotopic organization of the vagal motor nuclei has provided insight into autonomic function in health and disease. To further define specific cellular identities, we paired information based on visceral connectivity with a cell-type specific marker of a subpopulation of neurons in the dorsal motor nucleus of the vagus (DMV) and nucleus ambiguus (nAmb) that express the autism-associated MET receptor tyrosine kinase. As gastrointestinal disturbances are common in children with autism spectrum disorder (ASD), we sought to define the relationship between MET-expressing (MET+) neurons in the DMV and nAmb, and the gastrointestinal tract. Using wholemount tissue staining and clearing, or retrograde tracing in a MET EGFP transgenic mouse, we identify three novel subpopulations of EGFP+ vagal brainstem neurons: (a) EGFP+ neurons in the nAmb projecting to the esophagus or laryngeal muscles, (b) EGFP+ neurons in the medial DMV projecting to the stomach, and (b) EGFP+ neurons in the lateral DMV projecting to the cecum and/or proximal colon. Expression of the MET ligand, hepatocyte growth factor (HGF), by tissues innervated by vagal motor neurons during fetal development reveal potential sites of HGF-MET interaction. Furthermore, similar cellular expression patterns of MET in the brainstem of both the mouse and nonhuman primate suggests that MET expression at these sites is evolutionarily conserved. Together, the data suggest that MET+ neurons in the brainstem vagal motor nuclei are anatomically positioned to regulate distinct portions of the gastrointestinal tract, with implications for the pathophysiology of gastrointestinal comorbidities of ASD. © 2017 Wiley Periodicals, Inc.

Long-term outcome of accessory nerve to suprascapular nerve transfer in obstetric brachial plexus lesion: functional, morphological, and electrophysiological results.

PubMed

Gmeiner, Matthias; Topakian, Raffi; Göschl, Manuel; Wurm, Sarah; Holzinger, Anita; van Ouwerkerk, Willem J R; Holl, Kurt

2015-09-01

An accessory to suprascapular nerve (XIN-SSN) transfer is considered in patients with obstetric brachial plexus lesion who fail to recover active shoulder external rotation. The aim of this study was to evaluate the quality of extraplexal suprascapular nerve neurotization and to perform a detailed analysis of the infraspinatus muscle (IM) and shoulder external rotation. A XIN-SSN transfer was performed in 14 patients between 2000 and 2007. Patients had been operated at the age of 3.7 ± 2.8 years. Follow-up examinations were conducted up to 8.5 ± 2.5 years. Magnetic resonance imaging was performed to investigate muscle trophism. Fatty muscle degeneration of the IM was classified according to the Goutallier classification. We conducted nerve conduction velocity studies of the suprascapular nerve and needle electromyography of the IM to assess pathologic spontaneous activity and interference patterns. Active glenohumeral shoulder external rotation and global shoulder function were evaluated using the Mallet score. Postoperatively, growth of the IM increased equally on the affected and unaffected sides, although significant differences of muscle thickness persisted over time. There was only grade 1 or 2 fatty degeneration pre- and postoperatively. Electromyography of the IM revealed a full interference pattern in all except one patient, and there was no pathological spontaneous activity. Glenohumeral external rotation as well as global shoulder function increased significantly. Our results indicate that the anastomosis after XIN-SSN transfer is functional and that successful reinnervation of the infraspinatus muscle may enable true glenohumeral active external rotation.

Functional nerve disorders in the athlete's foot, ankle, and leg.

PubMed

Baxter, D E

1993-01-01

Although neuropathies in the athlete's foot, ankle, and leg are uncommon, they are often underdiagnosed, primarily because of the complex interplay of causative factors. The physician should be aware of the possible occurrence of these neuropathies, and should be familiar with the anatomy and course of the nerves. Often, the problem only occurs during functional activity and cannot be demonstrated during the routine static examination. Other problems should also be considered when there is the possibility of a nerve compression syndrome. Metabolic processes, such as diabetes or abuse of alcohol, can certainly cause neuropathies. A double crush syndrome or pain from a higher source should also be considered. Finally, if surgery is done for chronic problems, only the area of constriction should be released, without interfering with the nerve itself. Release the fascia but leave the perineural fat intact. If instability is a factor, the joint should also be stabilized.

Loss of vagal tone aggravates systemic inflammation and cardiac impairment in endotoxemic rats.

PubMed

Schulte, Astrid; Lichtenstern, Christoph; Henrich, Michael; Weigand, Markus A; Uhle, Florian

2014-05-15

During the course of sepsis, often myocardial depression with hemodynamic impairment occurs. Acetylcholine, the main transmitter of the parasympathetic Nervus vagus, has been shown to be of importance for the transmission of signals within the immune system and also for a variety of other functions throughout the organism. Hypothesizing a potential correlation between this dysfunction and hemodynamic impairment, we wanted to assess the impact of vagal stimulation on myocardial inflammation and function in a rat model of lipopolysaccharide (LPS)-induced septic shock. As the myocardial tissue is (sparsely) innervated by the N. vagus, there might be an important anti-inflammatory effect in the heart, inhibiting proinflammatory gene expression in cardiomyocytes and improving cardiac function. We performed stimulation of the right cervical branch of the N. vagus in vagotomized, endotoxemic (1 mg/kg body weight LPS, intravenously) rats. Hemodynamic parameters were assessed over time using a left ventricular pressure-volume catheter. After the experiments, hearts and blood plasma were collected, and the expression of proinflammatory cytokines was measured using quantitative reverse transcription polymerase chain reaction and enzyme-linked immunosorbent assay. After vagotomy, the inflammatory response was aggravated, measurable by elevated cytokine levels in plasma and ventricular tissue. In concordance, cardiac impairment during septic shock was pronounced in these animals. To reverse both hemodynamic and immunologic effects of diminished vagal tone, even a brief stimulation of the N. vagus was enough during initial LPS infusion. Overall, the N. vagus might play a major role in maintaining hemodynamic stability and cardiac immune homeostasis during septic shock. Copyright © 2014 Elsevier Inc. All rights reserved.

Affective and physiological responses to the suffering of others: compassion and vagal activity.

PubMed

Stellar, Jennifer E; Cohen, Adam; Oveis, Christopher; Keltner, Dacher

2015-04-01

Compassion is an affective response to another's suffering and a catalyst of prosocial behavior. In the present studies, we explore the peripheral physiological changes associated with the experience of compassion. Guided by long-standing theoretical claims, we propose that compassion is associated with activation in the parasympathetic autonomic nervous system through the vagus nerve. Across 4 studies, participants witnessed others suffer while we recorded physiological measures, including heart rate, respiration, skin conductance, and a measure of vagal activity called respiratory sinus arrhythmia (RSA). Participants exhibited greater RSA during the compassion induction compared with a neutral control (Study 1), another positive emotion (Study 2), and a prosocial emotion lacking appraisals of another person's suffering (Study 3). Greater RSA during the experience of compassion compared with the neutral or control emotion was often accompanied by lower heart rate and respiration but no difference in skin conductance. In Study 4, increases in RSA during compassion positively predicted an established composite of compassion-related words, continuous self-reports of compassion, and nonverbal displays of compassion. Compassion, a core affective component of empathy and prosociality, is associated with heightened parasympathetic activity. (c) 2015 APA, all rights reserved).

Roux-en-Y gastric bypass reverses the effects of diet-induced obesity to inhibit the responsiveness of central vagal motoneurones.

PubMed

Browning, Kirsteen N; Fortna, Samuel R; Hajnal, Andras

2013-05-01

Diet-induced obesity (DIO) has been shown to alter the biophysical properties and pharmacological responsiveness of vagal afferent neurones and fibres, although the effects of DIO on central vagal neurones or vagal efferent functions have never been investigated. The aims of this study were to investigate whether high-fat diet-induced DIO also affects the properties of vagal efferent motoneurones, and to investigate whether these effects were reversed following weight loss induced by Roux-en-Y gastric bypass (RYGB) surgery. Whole-cell patch-clamp recordings were made from rat dorsal motor nucleus of the vagus (DMV) neurones in thin brainstem slices. The DMV neurones from rats exposed to high-fat diet for 12-14 weeks were less excitable, with a decreased membrane input resistance and decreased ability to fire action potentials in response to direct current pulse injection. The DMV neurones were also less responsive to superfusion with the satiety neuropeptides cholecystokinin and glucagon-like peptide 1. Roux-en-Y gastric bypass reversed all of these DIO-induced effects. Diet-induced obesity also affected the morphological properties of DMV neurones, increasing their size and dendritic arborization; RYGB did not reverse these morphological alterations. Remarkably, independent of diet, RYGB also reversed age-related changes of membrane properties and occurrence of charybdotoxin-sensitive (BK) calcium-dependent potassium current. These results demonstrate that DIO also affects the properties of central autonomic neurones by decreasing the membrane excitability and pharmacological responsiveness of central vagal motoneurones and that these changes were reversed following RYGB. In contrast, DIO-induced changes in morphological properties of DMV neurones were not reversed following gastric bypass surgery, suggesting that they may be due to diet, rather than obesity. These findings represent the first direct evidence for the plausible effect of RYGB to improve vagal

Roux-en-Y gastric bypass reverses the effects of diet-induced obesity to inhibit the responsiveness of central vagal motoneurones

PubMed Central

Browning, Kirsteen N; Fortna, Samuel R; Hajnal, Andras

2013-01-01

Diet-induced obesity (DIO) has been shown to alter the biophysical properties and pharmacological responsiveness of vagal afferent neurones and fibres, although the effects of DIO on central vagal neurones or vagal efferent functions have never been investigated. The aims of this study were to investigate whether high-fat diet-induced DIO also affects the properties of vagal efferent motoneurones, and to investigate whether these effects were reversed following weight loss induced by Roux-en-Y gastric bypass (RYGB) surgery. Whole-cell patch-clamp recordings were made from rat dorsal motor nucleus of the vagus (DMV) neurones in thin brainstem slices. The DMV neurones from rats exposed to high-fat diet for 12–14 weeks were less excitable, with a decreased membrane input resistance and decreased ability to fire action potentials in response to direct current pulse injection. The DMV neurones were also less responsive to superfusion with the satiety neuropeptides cholecystokinin and glucagon-like peptide 1. Roux-en-Y gastric bypass reversed all of these DIO-induced effects. Diet-induced obesity also affected the morphological properties of DMV neurones, increasing their size and dendritic arborization; RYGB did not reverse these morphological alterations. Remarkably, independent of diet, RYGB also reversed age-related changes of membrane properties and occurrence of charybdotoxin-sensitive (BK) calcium-dependent potassium current. These results demonstrate that DIO also affects the properties of central autonomic neurones by decreasing the membrane excitability and pharmacological responsiveness of central vagal motoneurones and that these changes were reversed following RYGB. In contrast, DIO-induced changes in morphological properties of DMV neurones were not reversed following gastric bypass surgery, suggesting that they may be due to diet, rather than obesity. These findings represent the first direct evidence for the plausible effect of RYGB to improve vagal

Distribution of AMPA receptor subunits GluR1-4 in the dorsal vagal complex of the rat: a light and electron microscope immunocytochemical study.

PubMed

Kessler, J P; Baude, A

1999-10-01

The dorsal vagal complex, localized in the dorsomedial medulla, includes the nucleus tractus solitarii (NTS), the dorsal motor nucleus of the vagus nerve (DMN) and the area postrema (AP). The distribution of AMPA-preferring glutamate receptors (AMPA receptors) within this region was investigated using immunohistochemistry and antibodies recognizing either one (GluR1 or GluR4) or two (GluR2 and GluR3) AMPA receptors subunits. The distribution of GluR1 immunoreactivity showed high contrast of staining between strongly and lightly labeled areas. Labeling was intense in the AP and weak in the NTS, except for its medial and dorsalmost parts which exhibited moderate staining. Almost no GluR1 immunoreactivity was found in the DMN. GluR2/3 immunolabeling was present in the entire dorsal vagal complex. This labeling was strong in the AP, the DMN and the medial half of the NTS and moderate in the lateral half of the NTS, except for the interstitial subdivision which exhibited intense staining. Labeling induced by the GluR4 antibody was very weak throughout the dorsal vagal complex. Ultrastructural examination showed that GluR1 and GluR2/3 immunoreactivity was localized in neuronal cell bodies and dendrites. No labeled axon terminal or glial cell body was found. Immunoperoxidase staining in labeled cell bodies and dendrites was associated with intracellular organelles (microtubules, mitochondria, cisternae of the endoplasmic reticulum,.) and/or parts of the plasma membrane. Plasma membrane labeling was often associated with asymmetrical synaptic differentiations. No labeled symmetrical synapse was found using either GluR1 or GluR2/3 antibody. The present results show that AMPA receptors have a widespread distribution in neuronal perikarya and dendrites of the rat dorsal vagal complex. They suggest differences in subunit composition between AMPA receptors localized in the NTS, the DMN and the AP. Ultrastructural data are consistent with the fact that AMPA receptors associated

Aldosterone increases cardiac vagal tone via G protein-coupled oestrogen receptor activation

PubMed Central

Brailoiu, G Cristina; Benamar, Khalid; Arterburn, Jeffrey B; Gao, Erhe; Rabinowitz, Joseph E; Koch, Walter J; Brailoiu, Eugen

2013-01-01

In addition to acting on mineralocorticoid receptors, aldosterone has been recently shown to activate the G protein-coupled oestrogen receptor (GPER) in vascular cells. In light of the newly identified role for GPER in vagal cardiac control, we examined whether or not aldosterone activates GPER in rat nucleus ambiguus. Aldosterone produced a dose-dependent increase in cytosolic Ca2+ concentration in retrogradely labelled cardiac vagal neurons of nucleus ambiguus; the response was abolished by pretreatment with the GPER antagonist G-36, but was not affected by the mineralocorticoid receptor antagonists, spironolactone and eplerenone. In Ca2+-free saline, the response to aldosterone was insensitive to blockade of the Ca2+ release from lysosomes, while it was reduced by blocking the Ca2+ release via ryanodine receptors and abolished by blocking the IP3 receptors. Aldosterone induced Ca2+ influx via P/Q-type Ca2+ channels, but not via L-type and N-type Ca2+ channels. Aldosterone induced depolarization of cardiac vagal neurons of nucleus ambiguus that was sensitive to antagonism of GPER but not of mineralocorticoid receptor. in vivo studies, using telemetric measurement of heart rate, indicate that microinjection of aldosterone into the nucleus ambiguus produced a dose-dependent bradycardia in conscious, freely moving rats. Aldosterone-induced bradycardia was blocked by the GPER antagonist, but not by the mineralocorticoid receptor antagonists. In summary, we report for the first time that aldosterone decreases heart rate by activating GPER in cardiac vagal neurons of nucleus ambiguus. PMID:23878371

Potentiation of mouse vagal afferent mechanosensitivity by ionotropic and metabotropic glutamate receptors

PubMed Central

Slattery, James A; Page, Amanda J; Dorian, Camilla L; Brierley, Stuart M; Blackshaw, L Ashley

2006-01-01

Glutamate acts at central synapses via ionotropic (iGluR – NMDA, AMPA and kainate) and metabotropic glutamate receptors (mGluRs). Group I mGluRs are excitatory whilst group II and III are inhibitory. Inhibitory mGluRs also modulate peripherally the mechanosensitivity of gastro-oesophageal vagal afferents. Here we determined the potential of excitatory GluRs to play an opposing role in modulating vagal afferent mechanosensitivity, and investigated expression of receptor subunit mRNA within the nodose ganglion. The responses of mouse gastro-oesophageal vagal afferents to graded mechanical stimuli were investigated before and during application of selective GluR ligands to their peripheral endings. Two types of vagal afferents were tested: tension receptors, which respond to circumferential tension, and mucosal receptors, which respond only to mucosal stroking. The selective iGluR agonists NMDA and AMPA concentration-dependently potentiated afferent responses. Their corresponding antagonists AP-5 and NBQX alone attenuated mechanosensory responses as did the non-selective antagonist kynurenate. The kainate selective agonist SYM-2081 had minor effects on mechanosensitivity, and the antagonist UBP 302 was ineffective. The mGluR5 antagonist MTEP concentration-dependently inhibited mechanosensitivity. Efficacy of agonists and antagonists differed on mucosal and tension receptors. We conclude that excitatory modulation of afferent mechanosensitivity occurs mainly via NMDA, AMPA and mGlu5 receptors, and the role of each differs according to afferent subtypes. PCR data indicated that all NMDA, kainate and AMPA receptor subunits plus mGluR5 are expressed, and are therefore candidates for the neuromodulation we observed. PMID:16945965

Potentiation of mouse vagal afferent mechanosensitivity by ionotropic and metabotropic glutamate receptors.

PubMed

Slattery, James A; Page, Amanda J; Dorian, Camilla L; Brierley, Stuart M; Blackshaw, L Ashley

2006-11-15

Glutamate acts at central synapses via ionotropic (iGluR--NMDA, AMPA and kainate) and metabotropic glutamate receptors (mGluRs). Group I mGluRs are excitatory whilst group II and III are inhibitory. Inhibitory mGluRs also modulate peripherally the mechanosensitivity of gastro-oesophageal vagal afferents. Here we determined the potential of excitatory GluRs to play an opposing role in modulating vagal afferent mechanosensitivity, and investigated expression of receptor subunit mRNA within the nodose ganglion. The responses of mouse gastro-oesophageal vagal afferents to graded mechanical stimuli were investigated before and during application of selective GluR ligands to their peripheral endings. Two types of vagal afferents were tested: tension receptors, which respond to circumferential tension, and mucosal receptors, which respond only to mucosal stroking. The selective iGluR agonists NMDA and AMPA concentration-dependently potentiated afferent responses. Their corresponding antagonists AP-5 and NBQX alone attenuated mechanosensory responses as did the non-selective antagonist kynurenate. The kainate selective agonist SYM-2081 had minor effects on mechanosensitivity, and the antagonist UBP 302 was ineffective. The mGluR5 antagonist MTEP concentration-dependently inhibited mechanosensitivity. Efficacy of agonists and antagonists differed on mucosal and tension receptors. We conclude that excitatory modulation of afferent mechanosensitivity occurs mainly via NMDA, AMPA and mGlu5 receptors, and the role of each differs according to afferent subtypes. PCR data indicated that all NMDA, kainate and AMPA receptor subunits plus mGluR5 are expressed, and are therefore candidates for the neuromodulation we observed.

Exercise training augments the dynamic heart rate response to vagal but not sympathetic stimulation in rats.

PubMed

Mizuno, Masaki; Kawada, Toru; Kamiya, Atsunori; Miyamoto, Tadayoshi; Shimizu, Shuji; Shishido, Toshiaki; Smith, Scott A; Sugimachi, Masaru

2011-04-01

We examined the transfer function of autonomic heart rate (HR) control in anesthetized sedentary and exercise-trained (16 wk, treadmill for 1 h, 5 times/wk at 15 m/min and 15-degree grade) rats for comparison to HR variability assessed in the conscious resting state. The transfer function from sympathetic stimulation to HR response was similar between groups (gain, 4.2 ± 1.5 vs. 4.5 ± 1.5 beats·min(-1)·Hz(-1); natural frequency, 0.07 ± 0.01 vs. 0.08 ± 0.01 Hz; damping coefficient, 1.96 ± 0.55 vs. 1.69 ± 0.15; and lag time, 0.7 ± 0.1 vs. 0.6 ± 0.1 s; sedentary vs. exercise trained, respectively, means ± SD). The transfer gain from vagal stimulation to HR response was 6.1 ± 3.0 in the sedentary and 9.7 ± 5.1 beats·min(-1)·Hz(-1) in the exercise-trained group (P = 0.06). The corner frequency (0.11 ± 0.05 vs. 0.17 ± 0.09 Hz) and lag time (0.1 ± 0.1 vs. 0.2 ± 0.1 s) did not differ between groups. When the sympathetic transfer gain was averaged for very-low-frequency and low-frequency bands, no significant group effect was observed. In contrast, when the vagal transfer gain was averaged for very-low-frequency, low-frequency, and high-frequency bands, exercise training produced a significant group effect (P < 0.05 by two-way, repeated-measures ANOVA). These findings suggest that, in the frequency domain, exercise training augments the dynamic HR response to vagal stimulation but not sympathetic stimulation, regardless of the frequency bands.

Nanofiber Nerve Guide for Peripheral Nerve Repair and Regeneration

DTIC Science & Technology

2016-04-01

faster regeneration and functional recovery. Peripheral nerve injury is a common complication of complex tissue trauma and often results in significant...having poor regeneration overall, the areas of regenerating nerve tissue could often be found in sections of the nerve guide where luminal spaces of...conducted in this Aim also provided important insight into the NGC design parameters necessary to allow for maximum nerve tissue ingrowth and regeneration

Cranial nerve clock. Part II: functional MR imaging of brain activation during a declarative memory task.

PubMed

Weiss, K L; Welsh, R C; Eldevik, P; Bieliauskas, L A; Steinberg, B A

2001-12-01

The authors performed this study to assess brain activation during encoding and successful recall with a declarative memory paradigm that has previously been demonstrated to be effective for teaching students about the cranial nerves. Twenty-four students underwent functional magnetic resonance (MR) imaging during encoding and recall of the name, number, and function of the 12 cranial nerves. The students viewed mnemonic graphic and text slides related to individual nerves, as well as their respective control slides. For the recall paradigm, students were prompted with the numbers 1-12 (test condition) intermixed with the number 14 (control condition). Subjects were tested about their knowledge of cranial nerves outside the MR unit before and after functional MR imaging. Students learned about the cranial nerves while undergoing functional MR imaging (mean post- vs preparadigm score, 8.1 +/- 3.4 [of a possible 12] vs 0.75 +/- 0.94, bilateral prefrontal cortex, left greater than right; P < 2.0 x 10(-12)) and maintained this knowledge at I week. The encoding and recall paradigms elicited distributed networks of brain activation. Encoding revealed statistically significant activation in the bilateral prefrontal cortex, left greater than right [corrected]; bilateral occipital and parietal associative cortices, parahippocampus region, fusiform gyri, and cerebellum. Successful recall activated the left much more than the right prefrontal, parietal associative, and anterior cingulate cortices; bilateral precuneus and cerebellum; and right more than the left posterior cingulate. A predictable pattern of brain activation at functional MR imaging accompanies the encoding and successful recall of the cranial nerves with this declarative memory paradigm.

Mother-infant dyadic reparation and individual differences in vagal tone affect 4-month-old infants' social stress regulation.

PubMed

Provenzi, Livio; Casini, Erica; de Simone, Paola; Reni, Gianluigi; Borgatti, Renato; Montirosso, Rosario

2015-12-01

Infants' social stress regulation (i.e., reactivity and recovery) might be affected by mother-infant dyadic functioning and infants' vagal tone (i.e., respiratory sinus arrhythmia, RSA). This study investigated the role of a specific dyadic functioning feature (i.e., dyadic reparation) and individual differences in vagal tone regulation (i.e., RSA suppression vs. non-suppression) in relation to social stress regulation in 4-month-old infants. A total of 65 mother-infant dyads participated in the face-to-face still-face paradigm. Social stress reactivity and recovery were measured as negative emotionality during Still-Face and Reunion episodes, respectively. RSA was measured during Play, Still-Face, and Reunion episodes. Suppressors had higher dyadic reparation during Play and higher recovery from social stress compared with non-suppressors. Higher reparation during Play was associated with lower reactivity and higher recovery only for suppressors. Findings suggest a joint role of infants' RSA individual differences and dyadic reparation in affecting infants' social stress regulation at 4 months of age. Copyright © 2015 Elsevier Inc. All rights reserved.

Functional regeneration of recurrent laryngeal nerve injury during thyroid surgery using an asymmetrically porous nerve guide conduit in an animal model.

PubMed

Choi, Jeong-Seok; Oh, Se Heang; An, Hye-Young; Kim, Young-Mo; Lee, Jin Ho; Lim, Jae-Yol

2014-01-01

Vocal cord paralysis (VCP) caused by recurrent laryngeal nerve (RLN) damage during thyroidectomy commonly results in serious medico-legal problems. The purpose of this study was to evaluate the usefulness of an asymmetrically porous polycaprolactone (PCL)/Pluronic F127 nerve guide conduit (NGC) for functional regeneration in a RLN injury animal model. A biodegradable, asymmetrically porous PCL/F127 NGC with selective permeability was fabricated for use in this study. A 10-mm segment of left RLN was resected in 28 New Zealand white rabbits, and then an asymmetrically porous NGC or a nonporous silicone tube was interposed between both stumps and securely fixed. Vocal cord mobility was endoscopically evaluated at one, four, and eight weeks postoperatively. Nerve growth through NGCs was assessed by toluidine blue staining, and thyroarytenoid (TA) muscle atrophy was evaluated by hematoxylin and eosin staining. Immunohistochemical stainings for acetylcholinesterase (AchE), anti-neurofilament (NF), and anti-S100 protein were also conducted, and transmission electron microscopy (TEM) was used to evaluate functional nerve regeneration. At eight weeks postoperatively, endoscopic evaluations showed significantly better recovery from VCP in the asymmetrically porous PCL/F127 NGC group (6 of 10 rabbits) than in the silicone tube group (1 of 10 rabbits). Continued nerve growth on the damaged nerve endings was observed with time in the asymmetrically porous PCL/F127 NGC-interposed RLNs. TA muscle dimensions and AchE expressions in TA muscle were significantly greater in the asymmetrically porous PCL/F127 NGC group than in the silicone tube group. Furthermore, immunohistochemical staining revealed the expression of NF and S100 protein in the regenerated nerves in the asymmetrically porous PCL/F127 NGC group at eight weeks postoperatively, and at this time, TEM imaging showed myelinated axons in the regenerated RLNs. The study shows that asymmetrically porous PCL/F127 NGC provides

Functional Regeneration of Recurrent Laryngeal Nerve Injury During Thyroid Surgery Using an Asymmetrically Porous Nerve Guide Conduit in an Animal Model

PubMed Central

Choi, Jeong-Seok; Oh, Se Heang; An, Hye-Young; Kim, Young-Mo; Lee, Jin Ho

2014-01-01

Background: Vocal cord paralysis (VCP) caused by recurrent laryngeal nerve (RLN) damage during thyroidectomy commonly results in serious medico-legal problems. The purpose of this study was to evaluate the usefulness of an asymmetrically porous polycaprolactone (PCL)/Pluronic F127 nerve guide conduit (NGC) for functional regeneration in a RLN injury animal model. Methods: A biodegradable, asymmetrically porous PCL/F127 NGC with selective permeability was fabricated for use in this study. A 10-mm segment of left RLN was resected in 28 New Zealand white rabbits, and then an asymmetrically porous NGC or a nonporous silicone tube was interposed between both stumps and securely fixed. Vocal cord mobility was endoscopically evaluated at one, four, and eight weeks postoperatively. Nerve growth through NGCs was assessed by toluidine blue staining, and thyroarytenoid (TA) muscle atrophy was evaluated by hematoxylin and eosin staining. Immunohistochemical stainings for acetylcholinesterase (AchE), anti-neurofilament (NF), and anti-S100 protein were also conducted, and transmission electron microscopy (TEM) was used to evaluate functional nerve regeneration. Results: At eight weeks postoperatively, endoscopic evaluations showed significantly better recovery from VCP in the asymmetrically porous PCL/F127 NGC group (6 of 10 rabbits) than in the silicone tube group (1 of 10 rabbits). Continued nerve growth on the damaged nerve endings was observed with time in the asymmetrically porous PCL/F127 NGC-interposed RLNs. TA muscle dimensions and AchE expressions in TA muscle were significantly greater in the asymmetrically porous PCL/F127 NGC group than in the silicone tube group. Furthermore, immunohistochemical staining revealed the expression of NF and S100 protein in the regenerated nerves in the asymmetrically porous PCL/F127 NGC group at eight weeks postoperatively, and at this time, TEM imaging showed myelinated axons in the regenerated RLNs. Conclusion: The study shows that

Upper Extremity Nerve Function and Pain in Human Volunteers with Narrow versus Wide Tourniquets.

PubMed

Kovar, Florian; Jauregui, Julio J; Specht, Stacy C; Baker, Erin; Bhave, Anil; Herzenberg, John E

2016-01-01

Nerve injury is a serious potential complication associated with clinical use of tourniquets during surgery. A novel narrow, single-use silicon ring tourniquet has been introduced, which may cause less nerve compression and provide a larger field of surgical exposure than standard wide tourniquets. We investigated both types of tourniquets in the non-dominant proximal upper arm of 15 healthy human volunteers. Pain and neurological effects were assessed during 15 minute trials with each tourniquet applied 1 week apart without anesthesia according to the manufacturers' recommendations. Median nerve function was studied using the pressure-specified sensory device, an instrumented two-point discriminator, and pain was assessed by two validated instruments. Skin sores, redness, nerve damage, or neurological complications did not occur in either group. Subjects reported more pain with the narrow tourniquet; however, measurable effect on median nerve function was the same in both groups. Tourniquet application with the narrow device was more efficient, the device was easier to use, and larger surgical field exposure was obtained. We conclude that the sensory deficit with the use of narrow tourniquets is not greater than that observed with pneumatic/wide tourniquets.

Functional Self-Assembling Peptide Nanofiber Hydrogels Designed for Nerve Degeneration.

PubMed

Sun, Yuqiao; Li, Wen; Wu, Xiaoli; Zhang, Na; Zhang, Yongnu; Ouyang, Songying; Song, Xiyong; Fang, Xinyu; Seeram, Ramakrishna; Xue, Wei; He, Liumin; Wu, Wutian

2016-01-27

Self-assembling peptide (SAP) RADA16-I (Ac-(RADA)4-CONH2) has been suffering from a main drawback associated with low pH, which damages cells and host tissues upon direct exposure. In this study, we presented a strategy to prepare nanofiber hydrogels from two designer SAPs at neutral pH. RADA16-I was appended with functional motifs containing cell adhesion peptide RGD and neurite outgrowth peptide IKVAV. The two SAPs were specially designed to have opposite net charges at neutral pH, the combination of which created a nanofiber hydrogel (-IKVAV/-RGD) characterized by significantly higher G' than G″ in a viscoelasticity examination. Circular dichroism, Fourier transform infrared spectroscopy, and Raman measurements were performed to investigate the secondary structure of the designer SAPs, indicating that both the hydrophobic/hydrophilic properties and electrostatic interactions of the functional motifs play an important role in the self-assembling behavior of the designer SAPs. The neural progenitor cells (NPCs)/stem cells (NSCs) fully embedded in the 3D-IKVAV/-RGD nanofiber hydrogel survived, whereas those embedded within the RADA 16-I hydrogel hardly survived. Moreover, the -IKVAV/-RGD nanofiber hydrogel supported NPC/NSC neuron and astrocyte differentiation in a 3D environment without adding extra growth factors. Studies of three nerve injury models, including sciatic nerve defect, intracerebral hemorrhage, and spinal cord transection, indicated that the designer -IKVAV/-RGD nanofiber hydrogel provided a more permissive environment for nerve regeneration than the RADA 16-I hydrogel. Therefore, we reported a new mechanism that might be beneficial for the synthesis of SAPs for in vitro 3D cell culture and nerve regeneration.

A silk sericin/silicone nerve guidance conduit promotes regeneration of a transected sciatic nerve.

PubMed

Xie, Hongjian; Yang, Wen; Chen, Jianghai; Zhang, Jinxiang; Lu, Xiaochen; Zhao, Xiaobo; Huang, Kun; Li, Huili; Chang, Panpan; Wang, Zheng; Wang, Lin

2015-10-28

Peripheral nerve gap defects lead to significant loss of sensory or motor function. Tissue engineering has become an important alternative to nerve repair. Sericin, a major component of silk, is a natural protein whose value in tissue engineering has just begun to be explored. Here, the first time use of sericin in vivo is reported as a long-term implant for peripheral nerve regeneration. A sericin nerve guidance conduit is designed and fabricated. This conduit is highly porous with mechanical strength matching peripheral nerve tissue. It supports Schwann cell proliferation and is capable of up-regulating the transcription of glial cell derived neurotrophic factor and nerve growth factor in Schwann cells. The sericin conduit wrapped with a silicone conduit (sericin/silicone double conduits) is used for bridging repair of a 5 mm gap in a rat sciatic nerve transection model. The sericin/silicone double conduits achieve functional recovery comparable to that of autologous nerve grafting as evidenced by drastically improved nerve function and morphology. Importantly, this improvement is mainly attributed to the sericin conduit as the silicone conduit alone only produces marginal functional recovery. This sericin/silicone-double-conduit strategy offers an efficient and valuable alternative to autologous nerve grafting for repairing damaged peripheral nerve. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The relationship of nerve fibre pathology to sensory function in entrapment neuropathy

PubMed Central

Schmid, Annina B.; Bland, Jeremy D. P.; Bhat, Manzoor A.

2014-01-01

Surprisingly little is known about the impact of entrapment neuropathy on target innervation and the relationship of nerve fibre pathology to sensory symptoms and signs. Carpal tunnel syndrome is the most common entrapment neuropathy; the aim of this study was to investigate its effect on the morphology of small unmyelinated as well as myelinated sensory axons and relate such changes to somatosensory function and clinical symptoms. Thirty patients with a clinical and electrophysiological diagnosis of carpal tunnel syndrome [17 females, mean age (standard deviation) 56.4 (15.3)] and 26 age and gender matched healthy volunteers [18 females, mean age (standard deviation) 51.0 (17.3)] participated in the study. Small and large fibre function was examined with quantitative sensory testing in the median nerve territory of the hand. Vibration and mechanical detection thresholds were significantly elevated in patients with carpal tunnel syndrome (P < 0.007) confirming large fibre dysfunction and patients also presented with increased thermal detection thresholds (P < 0.0001) indicative of C and Aδ-fibre dysfunction. Mechanical and thermal pain thresholds were comparable between groups (P > 0.13). A skin biopsy was taken from a median nerve innervated area of the proximal phalanx of the index finger. Immunohistochemical staining for protein gene product 9.5 and myelin basic protein was used to evaluate morphological features of unmyelinated and myelinated axons. Evaluation of intraepidermal nerve fibre density showed a striking loss in patients (P < 0.0001) confirming a significant compromise of small fibres. The extent of Meissner corpuscles and dermal nerve bundles were comparable between groups (P > 0.07). However, patients displayed a significant increase in the percentage of elongated nodes (P < 0.0001), with altered architecture of voltage-gated sodium channel distribution. Whereas neither neurophysiology nor quantitative sensory testing correlated with patients�

Functionally specific renal sympathetic nerve fibers: role in cardiovascular regulation.

PubMed

DiBona, G F

2001-06-01

The sympathetic nervous system provides differentiated regulation of the functions of various organs. This differentiated regulation occurs through mechanisms that operate at multiple sites within the classic reflex arc: peripherally at the level of afferent input stimuli to various reflex pathways, centrally at the level of interconnections between various central neuron pools, and peripherally at the level of efferent fibers targeted to various effectors within the organ. In the kidney, increased renal sympathetic nerve activity regulates the functions of the intrarenal effectors: the tubules, the blood vessels, and the juxtaglomerular granular cells. This enables a physiologically appropriate coordination between the circulatory, filtration, reabsorptive, excretory, and renin secretory contributions to overall renal function. Anatomically, each of these effectors has a dual pattern of innervation consisting of a specific and selective innervation by unmyelinated slowly conducting C-type renal sympathetic nerve fibers and an innervation that is shared among all the effectors. This arrangement facilitates maximum flexibility in the coordination of the tubules, the blood vessels, and the juxtaglomerular granular cells so as to produce physiologically appropriate responses to a variety of homeostatic requirements.

Transcutaneous vagus nerve stimulation (tVNS) enhances recognition of emotions in faces but not bodies.

PubMed

Sellaro, Roberta; de Gelder, Beatrice; Finisguerra, Alessandra; Colzato, Lorenza S

2018-02-01

The polyvagal theory suggests that the vagus nerve is the key phylogenetic substrate enabling optimal social interactions, a crucial aspect of which is emotion recognition. A previous study showed that the vagus nerve plays a causal role in mediating people's ability to recognize emotions based on images of the eye region. The aim of this study is to verify whether the previously reported causal link between vagal activity and emotion recognition can be generalized to situations in which emotions must be inferred from images of whole faces and bodies. To this end, we employed transcutaneous vagus nerve stimulation (tVNS), a novel non-invasive brain stimulation technique that causes the vagus nerve to fire by the application of a mild electrical stimulation to the auricular branch of the vagus nerve, located in the anterior protuberance of the outer ear. In two separate sessions, participants received active or sham tVNS before and while performing two emotion recognition tasks, aimed at indexing their ability to recognize emotions from facial and bodily expressions. Active tVNS, compared to sham stimulation, enhanced emotion recognition for whole faces but not for bodies. Our results confirm and further extend recent observations supporting a causal relationship between vagus nerve activity and the ability to infer others' emotional state, but restrict this association to situations in which the emotional state is conveyed by the whole face and/or by salient facial cues, such as eyes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Intraoperative cranial nerve monitoring.

PubMed

Harper, C Michel

2004-03-01

The purpose of intraoperative monitoring is to preserve function and prevent injury to the nervous system at a time when clinical examination is not possible. Cranial nerves are delicate structures and are susceptible to damage by mechanical trauma or ischemia during intracranial and extracranial surgery. A number of reliable electrodiagnostic techniques, including nerve conduction studies, electromyography, and the recording of evoked potentials have been adapted to the study of cranial nerve function during surgery. A growing body of evidence supports the utility of intraoperative monitoring of cranial nerve nerves during selected surgical procedures.

Sensory and motor peripheral nerve function and lower-extremity quadriceps strength: the health, aging and body composition study.

PubMed

Strotmeyer, Elsa S; de Rekeneire, Nathalie; Schwartz, Ann V; Resnick, Helaine E; Goodpaster, Bret H; Faulkner, Kimberly A; Shorr, Ronald I; Vinik, Aaron I; Harris, Tamara B; Newman, Anne B

2009-11-01

To determine whether sensory and motor nerve function is associated cross-sectionally with quadriceps or ankle dorsiflexion strength in an older community-based population. Cross-sectional analyses within a longitudinal cohort study. Two U.S. clinical sites. Two thousand fifty-nine Health, Aging and Body Composition Study (Health ABC) participants (49.5% male, 36.7% black, aged 73-82) in 2000/01. Quadriceps and ankle strength were measured using an isokinetic dynamometer. Sensory and motor peripheral nerve function in the legs and feet was assessed using 10-g and 1.4-g monofilaments, vibration threshold, and peroneal motor nerve conduction amplitude and velocity. Monofilament insensitivity, poorest vibration threshold quartile (>60 mu), and poorest motor nerve conduction amplitude quartile (<1.7 mV) were associated with 11%, 7%, and 8% lower quadriceps strength (all P<.01), respectively, than in the best peripheral nerve function categories in adjusted linear regression models. Monofilament insensitivity and lowest amplitude quartile were both associated with 17% lower ankle strength (P<.01). Multivariate analyses were adjusted for demographic characteristics, diabetes mellitus, body composition, lifestyle factors, and chronic health conditions and included all peripheral nerve measures in the same model. Monofilament insensitivity (beta=-7.19), vibration threshold (beta=-0.097), and motor nerve conduction amplitude (beta=2.01) each contributed independently to lower quadriceps strength (all P<.01). Monofilament insensitivity (beta=-5.29) and amplitude (beta=1.17) each contributed independently to lower ankle strength (all P<.01). Neither diabetes mellitus status nor lean mass explained the associations between peripheral nerve function and strength. Reduced sensory and motor peripheral nerve function is related to poorer lower extremity strength in older adults, suggesting a mechanism for the relationship with lower extremity disability.

A model-based approach for the evaluation of vagal and sympathetic activities in a newborn lamb.

PubMed

Le Rolle, Virginie; Ojeda, David; Beuchée, Alain; Praud, Jean-Paul; Pladys, Patrick; Hernández, Alfredo I

2013-01-01

This paper proposes a baroreflex model and a recursive identification method to estimate the time-varying vagal and sympathetic contributions to heart rate variability during autonomic maneuvers. The baroreflex model includes baroreceptors, cardiovascular control center, parasympathetic and sympathetic pathways. The gains of the global afferent sympathetic and vagal pathways are identified recursively. The method has been validated on data from newborn lambs, which have been acquired during the application of an autonomic maneuver, without medication and under beta-blockers. Results show a close match between experimental and simulated signals under both conditions. The vagal and sympathetic contributions have been simulated and, as expected, it is possible to observe different baroreflex responses under beta-blockers compared to baseline conditions.

Functional collagen conduits combined with human mesenchymal stem cells promote regeneration after sciatic nerve transection in dogs.

PubMed

Cui, Yi; Yao, Yao; Zhao, Yannan; Xiao, Zhifeng; Cao, Zongfu; Han, Sufang; Li, Xing; Huan, Yong; Pan, Juli; Dai, Jianwu

2018-05-01

Numerous studies have focused on the development of novel and innovative approaches for the treatment of peripheral nerve injury using artificial nerve guide conduits. In this study, we attempted to bridge 3.5-cm defects of the sciatic nerve with a longitudinally oriented collagen conduit (LOCC) loaded with human umbilical cord mesenchymal stem cells (hUC-MSCs). The LOCC contains a bundle of longitudinally aligned collagenous fibres enclosed in a hollow collagen tube. Our previous studies showed that an LOCC combined with neurotrophic factors enhances peripheral nerve regeneration. However, it remained unknown whether an LOCC seeded with hUC-MSCs could also promote regeneration. In this study, using various histological and electrophysiological analyses, we found that an LOCC provides mechanical support to newly growing nerves and functions as a structural scaffold for cells, thereby stimulating sciatic nerve regeneration. The LOCC and hUC-MSCs synergistically promoted regeneration and improved the functional recovery in a dog model of sciatic nerve injury. Therefore, the combined use of an LOCC and hUC-MSCs might have therapeutic potential for the treatment of peripheral nerve injury. Copyright © 2018 John Wiley & Sons, Ltd.

Duodenal activation of cAMP-dependent protein kinase induces vagal afferent firing and lowers glucose production in rats.

PubMed

Rasmussen, Brittany A; Breen, Danna M; Luo, Ping; Cheung, Grace W C; Yang, Clair S; Sun, Biying; Kokorovic, Andrea; Rong, Weifang; Lam, Tony K T

2012-04-01

The duodenum senses nutrients to maintain energy and glucose homeostasis, but little is known about the signaling and neuronal mechanisms involved. We tested whether duodenal activation of adenosine 3',5'-cyclic monophosphate (cAMP)-dependent protein kinase A (PKA) is sufficient and necessary for cholecystokinin (CCK) signaling to trigger vagal afferent firing and regulate glucose production. In rats, we selectively activated duodenal PKA and evaluated changes in glucose kinetics during the pancreatic (basal insulin) pancreatic clamps and vagal afferent firing. The requirement of duodenal PKA signaling in glucose regulation was evaluated by inhibiting duodenal activation of PKA in the presence of infusion of the intraduodenal PKA agonist (Sp-cAMPS) or CCK1 receptor agonist (CCK-8). We also assessed the involvement of a neuronal network and the metabolic impact of duodenal PKA activation in rats placed on high-fat diets. Intraduodenal infusion of Sp-cAMPS activated duodenal PKA and lowered glucose production, in association with increased vagal afferent firing in control rats. The metabolic and neuronal effects of duodenal Sp-cAMPS were negated by coinfusion with either the PKA inhibitor H89 or Rp-CAMPS. The metabolic effect was also negated by coinfusion with tetracaine, molecular and pharmacologic inhibition of NR1-containing N-methyl-d-aspartate (NMDA) receptors within the dorsal vagal complex, or hepatic vagotomy in rats. Inhibition of duodenal PKA blocked the ability of duodenal CCK-8 to reduce glucose production in control rats, whereas duodenal Sp-cAMPS bypassed duodenal CCK resistance and activated duodenal PKA and lowered glucose production in rats on high-fat diets. We identified a neural glucoregulatory function of duodenal PKA signaling. Copyright © 2012 AGA Institute. Published by Elsevier Inc. All rights reserved.

Human Lymphatic Mesenteric Vessels: Morphology and Possible Function of Aminergic and NPY-ergic Nerve Fibers.

PubMed

D'Andrea, Vito; Panarese, Alessandra; Taurone, Samanta; Coppola, Luigi; Cavallotti, Carlo; Artico, Marco

2015-09-01

The lymphatic vessels have been studied in different organs from a morphological to a clinical point of view. Nevertheless, the knowledge of the catecholaminergic control of the lymphatic circulation is still incomplete. The aim of this work is to study the presence and distribution of the catecholaminergic and NPY-ergic nerve fibers in the whole wall of the human mesenteric lymphatic vessels in order to obtain knowledge about their morphology and functional significance. The following experimental procedures were performed: 1) drawing of tissue containing lymphatic vessels; 2) cutting of tissue; 3) staining of tissue; 4) staining of nerve fibers; 5) histofluorescence microscopy for the staining of catecholaminergic nerve fibers; 6) staining of neuropeptide Y like-immune reactivity; 7) biochemical assay of proteins; 8) measurement of noradrenaline; 9) quantitative analysis of images; 10) statistical analysis of data. Numerous nerve fibers run in the wall of lymphatic vessels. Many of them are catecholaminergic in nature. Some nerve fibers are NPY-positive. The biochemical results on noradrenaline amounts are in agreement with morphological results on catecholaminergic nerve fibers. Moreover, the morphometric results, obtained by the quantitative analysis of images and the subsequent statistical analysis of data, confirm all our morphological and biochemical data. The knowledge of the physiological or pathological mechanism regulating the functions of the lymphatic system is incomplete. Nevertheless the catecholaminergic nerve fibers of the human mesenteric lymphatic vessels come from the adrenergic periarterial plexuses of the mesenterial arterial bed. NPY-ergic nerve fibers may modulate the microcirculatory mesenterial bed in different pathological conditions.

The role of water intake on cardiac vagal reactivation after upper-body resistance exercise.

PubMed

Teixeira, A L; Ramos, P S; Marins, J B; Ricardo, D R

2015-03-01

The aim of this study was to assess the hypothesis that water intake will accelerate cardiac vagal reactivation after a single session of upper-body resistance exercise. 13 healthy men (26.5±5.9 years) with previous experience in resistance training were enrolled. In visits 1 and 2, participants performed the one-repetition maximum (1RM) test and retest with the bench press exercise. The sessions 3 and 4 were performed randomly, while participants consumed 500 ml (experimental visit) or 50 ml (control visit) of water immediately after 3 sets of maximum repetitions at 80% of 1RM. Cardiac vagal activity was represented by cardiac vagal index (CVI) measured before, immediately after and 30 min post-exercise. Additionally, heart rate and blood pressure were measured. The results show that CVI was higher 30 min post-exercise when 500 ml of water was ingested compared to 50 ml (1.39±0.07 vs. 1.23±0.07; p=0.02) (mean±SEM). Heart rate and blood pressure values were similar in both trials. We conclude that water intake accelerates post-resistance exercise cardiac vagal reactivation. These findings suggest that hydration after resistance exercise might be beneficial for cardiovascular safety in healthy subjects. © Georg Thieme Verlag KG Stuttgart · New York.

The importance of phrenic nerve preservation and its effect on long-term postoperative lung function after pneumonectomy.

PubMed

Kocher, Gregor J; Poulson, Jannie Lysgaard; Blichfeldt-Eckhardt, Morten Rune; Elle, Bo; Schmid, Ralph A; Licht, Peter B

2016-04-01

The importance of phrenic nerve preservation during pneumonectomy remains controversial. We previously demonstrated that preservation of the phrenic nerve in the immediate postoperative period preserved lung function by 3-5% but little is known about its long-term effects. We, therefore, decided to investigate the effect of temporary ipsilateral cervical phrenic nerve block on dynamic lung volumes in mid- to long-term pneumonectomy patients. We investigated 14 patients after a median of 9 years post pneumonectomy (range: 1-15 years). Lung function testing (spirometry) and fluoroscopic and/or sonographic assessment of diaphragmatic motion on the pneumonectomy side were performed before and after ultrasonographic-guided ipsilateral cervical phrenic nerve block by infiltration with lidocaine. Ipsilateral phrenic nerve block was successfully achieved in 12 patients (86%). In the remaining 2 patients, diaphragmatic motion was already paradoxical before the nerve block. We found no significant difference on dynamic lung function values (FEV1 'before' 1.39 ± 0.44 vs FEV1 'after' 1.38 ± 0.40; P = 0.81). Induction of a temporary diaphragmatic palsy did not significantly influence dynamic lung volumes in mid- to long-term pneumonectomy patients, suggesting that preservation of the phrenic nerve is of greater importance in the immediate postoperative period after pneumonectomy. © The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

[Valuation and prospect of function preserving gastrectomy].

PubMed

Wang, Shuchang; Yu, Site; Xu, Jia; Zhao, Gang

2017-10-25

Preserving gastric function and improving quality of life (QOL) is the tendency of surgery for early gastric cancer. Function preserving gastrectomy (FPG) is applied to modify the extent of surgery and to achieve better quality of life at the premise of radical resection. Pylorus-preserving gastrectomy is the most favorable approach of FPG with oncological safety, which can improve nutritional status and QOL via preserving pylorus and vagal nerve. Proximal gastrectomy is widely accepted as FPG for early upper 1/3 gastric cancer. However, the most optimal way of anastomosis is not yet solved. Sentinel node navigation is currently the most accurate approach for intraoperative diagnosis of lymph node metastasis, which stimulates the development of many kinds of FPG procedures for individual treatment. Nevertheless, more efforts should be made to reduce false negative rate of sentinel node biopsy. Herein we discuss the valuation and prospect of FPG.

Effects of the probiotic strain Lactobacillus johnsonii strain La1 on autonomic nerves and blood glucose in rats.

PubMed

Yamano, Toshihiko; Tanida, Mamoru; Niijima, Akira; Maeda, Keiko; Okumura, Nobuaki; Fukushima, Yoichi; Nagai, Katsuya

2006-10-12

Oral administration of Lactobacillus casei reportedly reduces blood glucose concentrations in a non-insulin-dependent diabetic KK-Ay mouse model. In order to determine if other lactobacillus strains affect glucose metabolism, we evaluated the effect of the probiotic strain Lactobacillus johnsonii La1 (LJLa1) strain on glucose metabolism in rats. Oral administration of LJLa1 via drinking water for 2 weeks inhibited the hyperglycemia induced by intracranial injection of 2-deoxy-D-glucose (2DG). We found that the hyperglucagonemic response induced by 2DG was also suppressed by LJLa1. Oral administration of LJLa1 for 2 weeks also reduced the elevation of blood glucose and glucagon levels after an oral glucose load in streptozotocin-diabetic rats. In addition, we recently observed that intraduodenal injection of LJLa1 reduced renal sympathetic nerve activity and enhanced gastric vagal nerve activity, suggesting that LJLa1 might affect glucose metabolism by changing autonomic nerve activity. Therefore, we evaluated the effect of intraduodenal administration of LJLa1 on adrenal sympathetic nerve activity (ASNA) in urethane-anesthetized rats, since the autonomic nervous system, including the adrenal sympathetic nerve, may be implicated in the control of the blood glucose levels. Indeed, we found that ASNA was suppressed by intraduodenal administration of LJLa1, suggesting that LJLa1 might improve glucose tolerance by reducing glucagon secretion via alteration of autonomic nerve activities.

The Relationship of Reduced Peripheral Nerve Function and Diabetes With Physical Performance in Older White and Black Adults

PubMed Central

Strotmeyer, Elsa S.; de Rekeneire, Nathalie; Schwartz, Ann V.; Faulkner, Kimberly A.; Resnick, Helaine E.; Goodpaster, Bret H.; Shorr, Ronald I.; Vinik, Aaron I.; Harris, Tamara B.; Newman, Anne B.

2008-01-01

OBJECTIVE—Poor peripheral nerve function is prevalent in diabetes and older populations, and it has great potential to contribute to poor physical performance. RESEARCH DESIGN AND METHODS—Cross-sectional analyses were done for the Health, Aging, and Body Composition (Health ABC) Study participants (n = 2,364; 48% men; 38% black; aged 73–82 years). Sensory and motor peripheral nerve function in legs/feet was assessed by 10- and 1.4-g monofilament perception, vibration detection, and peroneal motor nerve conduction amplitude and velocity. The Health ABC lower-extremity performance battery was a supplemented version of the Established Populations for the Epidemiologic Studies of the Elderly battery (chair stands, standing balance, and 6-m walk), adding increased stand duration, single foot stand, and narrow walk. RESULTS—Diabetic participants had fewer chair stands (0.34 vs. 0.36 stands/s), shorter standing balance time (0.69 vs. 0.75 ratio), slower usual walking speed (1.11 vs. 1.14 m/s), slower narrow walking speed (0.80 vs. 0.90 m/s), and lower performance battery score (6.43 vs. 6.93) (all P < 0.05). Peripheral nerve function was associated with each physical performance measure independently. After addition of peripheral nerve function in fully adjusted models, diabetes remained significantly related to a lower performance battery score and slower narrow walking speed but not to chair stands, standing balance, or usual walking speed. CONCLUSIONS—Poor peripheral nerve function accounts for a portion of worse physical performance in diabetes and may be directly associated with physical performance in older diabetic and nondiabetic adults. The impact of peripheral nerve function on incident disability should be evaluated in older adults. PMID:18535192

Electrophysiologic and functional evaluations of regenerated facial nerve defects with a tube containing dental pulp cells in rats.

PubMed

Sasaki, Ryo; Matsumine, Hajime; Watanabe, Yorikatsu; Takeuchi, Yuichi; Yamato, Masayuki; Okano, Teruo; Miyata, Mariko; Ando, Tomohiro

2014-11-01

Dental pulp tissue contains Schwann and neural progenitor cells. Tissue-engineered nerve conduits with dental pulp cells promote facial nerve regeneration in rats. However, no nerve functional or electrophysiologic evaluations were performed. This study investigated the compound muscle action potential recordings and facial functional analysis of dental pulp cell regenerated nerve in rats. A silicone tube containing rat dental pulp cells in type I collagen gel was transplanted into a 7-mm gap of the buccal branch of the facial nerve in Lewis rats; the same defect was created in the marginal mandibular branch, which was ligatured. Compound muscle action potential recordings of vibrissal muscles and facial functional analysis with facial palsy score of the nerve were performed. Tubulation with dental pulp cells showed significantly lower facial palsy scores than the autograft group between 3 and 10 weeks postoperatively. However, the dental pulp cell facial palsy scores showed no significant difference from those of autograft after 11 weeks. Amplitude and duration of compound muscle action potentials in the dental pulp cell group showed no significant difference from those of the intact and autograft groups, and there was no significant difference in the latency of compound muscle action potentials between the groups at 13 weeks postoperatively. However, the latency in the dental pulp cell group was prolonged more than that of the intact group. Tubulation with dental pulp cells could recover facial nerve defects functionally and electrophysiologically, and the recovery became comparable to that of nerve autografting in rats.

The effect of cavernous nerve traction on erectile function in rats

PubMed Central

Chen, Liping; Wang, Tao; Wang, Shaogang; Liu, Jihong

2017-01-01

We performed this study to evaluate the effect of cavernous nerve (CN) traction on erectile function in rats. Thirty-two 8- week-old Sprague–Dawley rats were divided into four groups: control, 1-minute CN traction, 2-minute CN traction, and 2-minute CN crush. CN traction was performed using a glass hook with a tensile force of 0.2 Newton. One month later, the mean arterial pressure (MAP) and intracavernosal pressure (ICP) in response to CN stimulation were measured to assess erectile function. The penis and major pelvic ganglion (MPG) were harvested to explore the expression of neuronal nitric oxide synthase (nNOS) and neurofilament, fibrosis and apoptosis. The ICP/MAP ratio was reduced in the 2-minute CN traction group compared with the control group (P < 0.05). The ICP/MAP ratio in the CN crush group was lower than in the other three groups (P < 0.05, for each). Expression of nNOS in both MPG and dorsal penile nerve was lower in the CN traction group than in the control group, but was higher than in the CN crush group (P < 0.05). Nerve fiber number in the dorsal penile nerve was reduced by 2-minute CN traction (P < 0.05). The ratios of collagen to smooth muscle content and the apoptosis were both increased the in 2-minute CN traction group compared with the control group (P < 0.05). The findings indicate that CN traction is an effective CN injury model and the injury it caused is relatively mild compared with the CN crush model. PMID:28982169

Roles for gut vagal sensory signals in determining energy availability and energy expenditure.

PubMed

Schwartz, Gary J

2018-08-15

The gut sensory vagus transmits a wide range of meal-related mechanical, chemical and gut peptide signals from gastrointestinal and hepatic tissues to the central nervous system at the level of the caudal brainstem. Results from studies using neurophysiological, behavioral physiological and metabolic approaches that challenge the integrity of this gut-brain axis support an important role for these gut signals in the negative feedback control of energy availability by limiting food intake during a meal. These experimental approaches have now been applied to identify important and unanticipated contributions of the vagal sensory gut-brain axis to the control of two additional effectors of overall energy balance: the feedback control of endogenous energy availability through hepatic glucose production and metabolism, and the control of energy expenditure through brown adipose tissue thermogenesis. Taken together, these studies reveal the pleiotropic influences of gut vagal meal-related signals on energy balance, and encourage experimental efforts aimed at understanding how the brainstem represents, organizes and coordinates gut vagal sensory signals with these three determinants of energy homeostasis. Copyright © 2018 Elsevier B.V. All rights reserved.

Renal denervation in male rats with heart failure improves ventricular sympathetic nerve innervation and function

PubMed Central

Pinkham, Maximilian I.; Loftus, Michael T.; Amirapu, Satya; Guild, Sarah-Jane; Quill, Gina; Woodward, William R.; Habecker, Beth A.

2017-01-01

Heart failure is characterized by the loss of sympathetic innervation to the ventricles, contributing to impaired cardiac function and arrhythmogenesis. We hypothesized that renal denervation (RDx) would reverse this loss. Male Wistar rats underwent myocardial infarction (MI) or sham surgery and progressed into heart failure for 4 wk before receiving bilateral RDx or sham RDx. After additional 3 wk, left ventricular (LV) function was assessed, and ventricular sympathetic nerve fiber density was determined via histology. Post-MI heart failure rats displayed significant reductions in ventricular sympathetic innervation and tissue norepinephrine content (nerve fiber density in the LV of MI+sham RDx hearts was 0.31 ± 0.05% vs. 1.00 ± 0.10% in sham MI+sham RDx group, P < 0.05), and RDx significantly increased ventricular sympathetic innervation (0.76 ± 0.14%, P < 0.05) and tissue norepinephrine content. MI was associated with an increase in fibrosis of the noninfarcted ventricular myocardium, which was attenuated by RDx. RDx improved LV ejection fraction and end-systolic and -diastolic areas when compared with pre-RDx levels. This is the first study to show an interaction between renal nerve activity and cardiac sympathetic nerve innervation in heart failure. Our findings show denervating the renal nerves improves cardiac sympathetic innervation and function in the post-MI failing heart. PMID:28052866

Effects of hyperglycemia on rat cavernous nerve axons: a functional and ultrastructural study.

PubMed

Zotova, Elena G; Schaumburg, Herbert H; Raine, Cedric S; Cannella, Barbara; Tar, Moses; Melman, Arnold; Arezzo, Joseph C

2008-10-01

The present study explored parallel changes in the physiology and structure of myelinated (Adelta) and unmyelinated (C) small diameter axons in the cavernous nerve of rats associated with streptozotocin-induced hyperglycemia. Damage to these axons is thought to play a key role in diabetic autonomic neuropathy and erectile dysfunction, but their pathophysiology has been poorly studied. Velocities in slow conducting fibers were measured by applying multiple unit procedures; histopathology was evaluated with both light and electron microscopy. To our knowledge, these are the initial studies of slow nerve conduction velocities in the distal segments of the cavernous nerve. We report that hyperglycemia is associated with a substantial reduction in the amplitude of the slow conducting response, as well as a slowing of velocities within this very slow range (< 2.5 m/s). Even with prolonged hyperglycemia (> 4 months), histopathological abnormalities were mild and limited to the distal segments of the cavernous nerve. Structural findings included dystrophic changes in nerve terminals, abnormal accumulations of glycogen granules in unmyelinated and preterminal axons, and necrosis of scattered smooth muscle fibers. The onset of slowing of velocity in the distal cavernous nerve occurred subsequent to slowing in somatic nerves in the same rats. The functional changes in the cavernous nerve anticipated and exceeded the axonal degeneration detected by morphology. The physiologic techniques outlined in these studies are feasible in most electrophysiologic laboratories and could substantially enhance our sensitivity to the onset and progression of small fiber diabetic neuropathy.

EFFECTS OF HYPERGLYCEMIA ON RAT CAVERNOUS NERVE AXONS: A FUNCTIONAL AND ULTRASTRUCTURAL STUDY

PubMed Central

Zotova, Elena G.; Schaumburg, Herbert H.; Raine, Cedric S.; Cannella, Barbara; Tar, Moses; Melman, Arnold; Arezzo, Joseph C.

2008-01-01

The present study explored parallel changes in the physiology and structure of myelinated (Aδ) and unmyelinated (C) small diameter axons in the cavernous nerve of rats associated with streptozotocin-induced hyperglycemia. Damage to these axons is thought to play a key role in diabetic autonomic neuropathy and erectile dysfunction, but their pathophysiology has been poorly studied. Velocities in slow conducting fibers were measured by applying multiple unit procedures; histopathology was evaluated with both light and electron microscopy. To our knowledge, these are the initial studies of slow nerve conduction velocities in the distal segments of the cavernous nerve. We report that hyperglycemia is associated with a substantial reduction in the amplitude of the slow conducting response, as well as a slowing of velocities within this very slow range (<2.5 m/sec). Even with prolonged hyperglycemia (> 4 months), histopathological abnormalities were mild and limited to the distal segments of the cavernous nerve. Structural findings included dystrophic changes in nerve terminals, abnormal accumulations of glycogen granules in unmyelinated and preterminal axons, and necrosis of scattered smooth muscle fibers. The onset of slowing of velocity in the distal cavernous nerve occurred subsequent to slowing in somatic nerves in the same rats. The functional changes in the cavernous nerve anticipated and exceeded the axonal degeneration detected by morphology. The physiologic techniques outlined in these studies are feasible in most electrophysiologic laboratories and could substantially enhance our sensitivity to the onset and progression of small fiber diabetic neuropathy. PMID:18687329

Use of Nerve Conduction Velocity to Assess Peripheral Nerve Health in Aging Mice

PubMed Central

Walsh, Michael E.; Sloane, Lauren B.; Fischer, Kathleen E.; Austad, Steven N.; Richardson, Arlan

2015-01-01

Nerve conduction velocity (NCV), the speed at which electrical signals propagate along peripheral nerves, is used in the clinic to evaluate nerve function in humans. A decline in peripheral nerve function is associated with a number of age-related pathologies. While several studies have shown that NCV declines with age in humans, there is little information on the effect of age on NCV in peripheral nerves in mice. In this study, we evaluated NCV in male and female C57Bl/6 mice ranging from 4 to 32 months of age. We observed a decline in NCV in both male and female mice after 20 months of age. Sex differences were detected in sensory NCV as well as the rate of decline during aging in motor nerves; female mice had slower sensory NCV and a slower age-related decline in motor nerves compared with male mice. We also tested the effect of dietary restriction on NCV in 30-month-old female mice. Dietary restriction prevented the age-related decline in sciatic NCV but not other nerves. Because NCV is clinically relevant to the assessment of nerve function, we recommend that NCV be used to evaluate healthspan in assessing genetic and pharmacological interventions that increase the life span of mice. PMID:25477428

The serotonin receptor mediates changes in autonomic neurotransmission and gastrointestinal transit induced by heat-killed Lactobacillus brevis SBC8803.

PubMed

Horii, Y; Nakakita, Y; Misonou, Y; Nakamura, T; Nagai, K

2015-01-01

Lactobacilli exhibit several health benefits in mammals, including humans. Our previous reports established that heat-killed Lactobacillus brevis SBC8803 (SBC8803) increased both efferent gastric vagal nerve activity and afferent intestinal vagal nerve activity in rats. We speculated that this strain could be useful for the treatment of gastrointestinal (GI) disorders. In this study, we examined the effects of SBC8803 on peristalsis and the activity of the efferent celiac vagal nerve innervating the intestine in rats. First, we examined the effects of intraduodenal (ID) administration of SBC8803 on efferent celiac vagal nerve activity (efferent CVNA) in urethane-anesthetised rats using electrophysiological studies. The effects of intravenous injection of the serotonin 5-HT3 receptor antagonist granisetron on changes in efferent CVNA due to ID administration of SBC8803 were also investigated. Finally, the effects of oral gavage of SBC8803 on GI transit were analysed using the charcoal propulsion method in conscious rats treated with or without granisetron. ID administration of SBC8803 increased efferent CVNA. Pretreatment with granisetron eliminated SBC8803-dependent changes in efferent CVNA. Furthermore, oral gavage of SBC8803 significantly accelerated GI transit, while pretreatment with granisetron inhibited GI transit. Our findings suggested that SBC8803 increased efferent CVNA and GI transit of charcoal meal via 5-HT3 receptors. Moreover, SBC8803 enhanced the activity of efferent vagal nerve innervating the intestine and promoted peristalsis via 5-HT3 receptors.

Subtotal resection for management of large jugular paragangliomas with functional lower cranial nerves.

PubMed

Wanna, George B; Sweeney, Alex D; Carlson, Matthew L; Latuska, Richard F; Rivas, Alejandro; Bennett, Marc L; Netterville, James L; Haynes, David S

2014-12-01

To evaluate tumor control following subtotal resection of advanced jugular paragangliomas in patients with functional lower cranial nerves and to investigate the utility of salvage radiotherapy for residual progressive disease. Case series with planned chart review. Tertiary academic referral center. Patients who presented with advanced jugular paragangliomas and functional lower cranial nerves were analyzed. Primary outcome measures included extent of resection, long-term tumor control, need for additional treatment, and postoperative lower cranial nerve function. Twelve patients (mean age, 46.2 years; 7 women, 58.3%) who met inclusion criteria were evaluated between 1999 and 2013. The mean postoperative residual tumor volume was 27.7% (range, 3.5%-75.0%) of the preoperative volume. When the residual tumor volume was less than 20% of the preoperative volume, no tumor growth occurred over an average of 44.6 months of follow-up (P < .01). Four tumors (33.3%) demonstrated serial growth at a mean of 23.5 months following resection, 2 of which were treated with salvage stereotactic radiotherapy providing control through the last recorded follow-up. No patient experienced permanent postoperative lower cranial neuropathy as a result of surgery. Subtotal resection of jugular paragangliomas with preservation of the lower cranial nerves is a viable management strategy. If more than 80% of the preoperative tumor volume is resected, the residual tumor seems less likely to grow. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2014.

Pre-differentiation of mesenchymal stromal cells in combination with a microstructured nerve guide supports peripheral nerve regeneration in the rat sciatic nerve model.

PubMed

Boecker, Arne Hendrik; van Neerven, Sabien Geraldine Antonia; Scheffel, Juliane; Tank, Julian; Altinova, Haktan; Seidensticker, Katrin; Deumens, Ronald; Tolba, Rene; Weis, Joachim; Brook, Gary Anthony; Pallua, Norbert; Bozkurt, Ahmet

2016-02-01

Many bioartificial nerve guides have been investigated pre-clinically for their nerve regeneration-supporting function, often in comparison to autologous nerve transplantation, which is still regarded as the current clinical gold standard. Enrichment of these scaffolds with cells intended to support axonal regeneration has been explored as a strategy to boost axonal regeneration across these nerve guides Ansselin et al. (1998). In the present study, 20 mm rat sciatic nerve defects were implanted with a cell-seeded microstructured collagen nerve guide (Perimaix) or an autologous nerve graft. Under the influence of seeded, pre-differentiated mesenchymal stromal cells, axons regenerated well into the Perimaix nerve guide. Myelination-related parameters, like myelin sheath thickness, benefitted from an additional seeding with pre-differentiated mesenchymal stromal cells. Furthermore, both the number of retrogradely labelled sensory neurons and the axon density within the implant were elevated in the cell-seeded scaffold group with pre-differentiated mesenchymal stromal cells. However, a pre-differentiation had no influence on functional recovery. An additional cell seeding of the Perimaix nerve guide with mesenchymal stromal cells led to an extent of functional recovery, independent of the differentiation status, similar to autologous nerve transplantation. These findings encourage further investigations on pre-differentiated mesenchymal stromal cells as a cellular support for peripheral nerve regeneration. © 2015 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Reduced Cardiac Vagal Modulation Impacts on Cognitive Performance in Chronic Fatigue Syndrome

PubMed Central

Beaumont, Alison; Burton, Alexander R.; Lemon, Jim; Bennett, Barbara K.; Lloyd, Andrew; Vollmer-Conna, Uté

2012-01-01

Background Cognitive difficulties and autonomic dysfunction have been reported separately in patients with chronic fatigue syndrome (CFS). A role for heart rate variability (HRV) in cognitive flexibility has been demonstrated in healthy individuals, but this relationship has not as yet been examined in CFS. The objective of this study was to examine the relationship between HRV and cognitive performance in patients with CFS. Methods Participants were 30 patients with CFS and 40 healthy controls; the groups were matched for age, sex, education, body mass index, and hours of moderate exercise/week. Questionnaires were used to obtain relevant medical and demographic information, and assess current symptoms and functional impairment. Electrocardiograms, perceived fatigue/effort and performance data were recorded during cognitive tasks. Between–group differences in autonomic reactivity and associations with cognitive performance were analysed. Results Patients with CFS showed no deficits in performance accuracy, but were significantly slower than healthy controls. CFS was further characterized by low and unresponsive HRV; greater heart rate (HR) reactivity and prolonged HR-recovery after cognitive challenge. Fatigue levels, perceived effort and distress did not affect cognitive performance. HRV was consistently associated with performance indices and significantly predicted variance in cognitive outcomes. Conclusions These findings reveal for the first time an association between reduced cardiac vagal tone and cognitive impairment in CFS and confirm previous reports of diminished vagal activity. PMID:23166694

The cardiac sympathetic co-transmitter galanin reduces acetylcholine release and vagal bradycardia: Implications for neural control of cardiac excitability

PubMed Central

Herring, Neil; Cranley, James; Lokale, Michael N.; Li, Dan; Shanks, Julia; Alston, Eric N.; Girard, Beatrice M.; Carter, Emma; Parsons, Rodney L.; Habecker, Beth A.; Paterson, David J.

2012-01-01

The autonomic phenotype of congestive cardiac failure is characterised by high sympathetic drive and impaired vagal tone, which are independent predictors of mortality. We hypothesize that impaired bradycardia to peripheral vagal stimulation following high-level sympathetic drive is due to sympatho-vagal crosstalk by the adrenergic co-transmitters galanin and neuropeptide-Y (NPY). Moreover we hypothesize that galanin acts similarly to NPY by reducing vagal acetylcholine release via a receptor mediated, protein kinase-dependent pathway. Prolonged right stellate ganglion stimulation (10 Hz, 2 min, in the presence of 10 μM metoprolol) in an isolated guinea pig atrial preparation with dual autonomic innervation leads to a significant (p < 0.05) reduction in the magnitude of vagal bradycardia (5 Hz) maintained over the subsequent 20 min (n = 6). Immunohistochemistry demonstrated the presence of galanin in a small number of tyrosine hydroxylase positive neurons from freshly dissected stellate ganglion tissue sections. Following 3 days of tissue culture however, most stellate neurons expressed galanin. Stellate stimulation caused the release of low levels of galanin and significantly higher levels of NPY into the surrounding perfusate (n = 6, using ELISA). The reduction in vagal bradycardia post sympathetic stimulation was partially reversed by the galanin receptor antagonist M40 after 10 min (1 μM, n = 5), and completely reversed with the NPY Y2 receptor antagonist BIIE 0246 at all time points (1 μM, n = 6). Exogenous galanin (n = 6, 50–500 nM) also reduced the heart rate response to vagal stimulation but had no effect on the response to carbamylcholine that produced similar degrees of bradycardia (n = 6). Galanin (500 nM) also significantly attenuated the release of 3H-acetylcholine from isolated atria during field stimulation (5 Hz, n = 5). The effect of galanin on vagal bradycardia could be abolished by the galanin receptor antagonist

Functional significance of the pattern of renal sympathetic nerve activation.

PubMed

Dibona, G F; Sawin, L L

1999-08-01

To assess the renal functional significance of the pattern of renal sympathetic nerve activation, computer-generated stimulus patterns (delivered at constant integrated voltage) were applied to the decentralized renal sympathetic nerve bundle and renal hemodynamic and excretory responses determined in anesthetized rats. When delivered at the same integrated voltage, stimulus patterns resembling those observed in in vivo multifiber recordings of renal sympathetic nerve activity (diamond-wave patterns) produced greater renal vasoconstrictor responses than conventional square-wave patterns. Within diamond-wave patterns, increasing integrated voltage by increasing amplitude produced twofold greater renal vasoconstrictor responses than by increasing duration. With similar integrated voltages that were subthreshold for renal vasoconstriction, neither diamond- nor square-wave pattern altered glomerular filtration rate, whereas diamond- but not square-wave pattern reversibly decreased urinary sodium excretion by 25 +/- 3%. At the same number of pulses per second, intermittent stimulation produced faster and greater renal vasoconstriction than continuous stimulation. At the same number of pulses per second, increases in rest period during intermittent stimulation proportionally augmented the renal vasoconstrictor response compared with that observed with continuous stimulation; the maximum augmentation of 55% occurred at a rest period of 500 ms. These results indicate that the pattern of renal sympathetic nerve stimulation (activity) significantly influences the rapidity, magnitude, and selectivity of the renal vascular and tubular responses.

Phrenic nerve transfer to the musculocutaneous nerve for the repair of brachial plexus injury: electrophysiological characteristics

PubMed Central

Liu, Ying; Xu, Xun-cheng; Zou, Yi; Li, Su-rong; Zhang, Bin; Wang, Yue

2015-01-01

Phrenic nerve transfer is a major dynamic treatment used to repair brachial plexus root avulsion. We analyzed 72 relevant articles on phrenic nerve transfer to repair injured brachial plexus that were indexed by Science Citation Index. The keywords searched were brachial plexus injury, phrenic nerve, repair, surgery, protection, nerve transfer, and nerve graft. In addition, we performed neurophysiological analysis of the preoperative condition and prognosis of 10 patients undergoing ipsilateral phrenic nerve transfer to the musculocutaneous nerve in our hospital from 2008 to 201 3 and observed the electromyograms of the biceps brachii and motor conduction function of the musculocutaneous nerve. Clinically, approximately 28% of patients had brachial plexus injury combined with phrenic nerve injury, and injured phrenic nerve cannot be used as a nerve graft. After phrenic nerve transfer to the musculocutaneous nerve, the regenerated potentials first appeared at 3 months. Recovery of motor unit action potential occurred 6 months later and became more apparent at 12 months. The percent of patients recovering ‘excellent’ and ‘good’ muscle strength in the biceps brachii was 80% after 18 months. At 12 months after surgery, motor nerve conduction potential appeared in the musculocutaneous nerve in seven cases. These data suggest that preoperative evaluation of phrenic nerve function may help identify the most appropriate nerve graft in patients with an injured brachial plexus. The functional recovery of a transplanted nerve can be dynamically observed after the surgery. PMID:25883637

Phrenic nerve transfer to the musculocutaneous nerve for the repair of brachial plexus injury: electrophysiological characteristics.

PubMed

Liu, Ying; Xu, Xun-Cheng; Zou, Yi; Li, Su-Rong; Zhang, Bin; Wang, Yue

2015-02-01

Phrenic nerve transfer is a major dynamic treatment used to repair brachial plexus root avulsion. We analyzed 72 relevant articles on phrenic nerve transfer to repair injured brachial plexus that were indexed by Science Citation Index. The keywords searched were brachial plexus injury, phrenic nerve, repair, surgery, protection, nerve transfer, and nerve graft. In addition, we performed neurophysiological analysis of the preoperative condition and prognosis of 10 patients undergoing ipsilateral phrenic nerve transfer to the musculocutaneous nerve in our hospital from 2008 to 201 3 and observed the electromyograms of the biceps brachii and motor conduction function of the musculocutaneous nerve. Clinically, approximately 28% of patients had brachial plexus injury combined with phrenic nerve injury, and injured phrenic nerve cannot be used as a nerve graft. After phrenic nerve transfer to the musculocutaneous nerve, the regenerated potentials first appeared at 3 months. Recovery of motor unit action potential occurred 6 months later and became more apparent at 12 months. The percent of patients recovering 'excellent' and 'good' muscle strength in the biceps brachii was 80% after 18 months. At 12 months after surgery, motor nerve conduction potential appeared in the musculocutaneous nerve in seven cases. These data suggest that preoperative evaluation of phrenic nerve function may help identify the most appropriate nerve graft in patients with an injured brachial plexus. The functional recovery of a transplanted nerve can be dynamically observed after the surgery.

Minocycline in leprosy patients with recent onset clinical nerve function impairment.

PubMed

Narang, Tarun; Arshdeep; Dogra, Sunil

2017-01-01

Nerve function impairment (NFI) in leprosy may occur and progress despite multidrug therapy alone or in combination with corticosteroids. We observed improvement in neuritis when minocycline was administered in patients with type 2 lepra reaction. This prompted us to investigate the role of minocycline in recent onset NFI, especially in corticosteroid unresponsive leprosy patients. Leprosy patients with recent onset clinical NFI (<6 months), as determined by Monofilament Test (MFT) and Voluntary Muscle Test (VMT), were recruited. Minocycline 100mg/day was given for 3 months to these patients. The primary outcome was the proportion of patients with 'restored,' 'improved,' 'stabilized,' or 'deteriorated' NFI. Secondary outcomes included any improvement in nerve tenderness and pain. In this pilot study, 11 patients were recruited. The progression of NFI was halted in all; with 9 out of 11 patients (81.82%) showing ?restored? or ?improved? sensory or motor nerve functions, on assessment with MFT and VMT. No serious adverse effects due to minocycline were observed. Our pilot study demonstrates the efficacy and safety of minocycline in recent onset NFI in leprosy patients. However, larger and long term comparative trials are needed to validate the efficacy of minocycline in leprosy neuropathy. © 2016 Wiley Periodicals, Inc.

Gene-Environment Contributions to the Development of Infant Vagal Reactivity: The Interaction of Dopamine and Maternal Sensitivity

ERIC Educational Resources Information Center

Propper, Cathi; Moore, Ginger A.; Mills-Koonce, W. Roger; Halpern, Carolyn Tucker; Hill-Soderlund, Ashley L.; Calkins, Susan D.; Carbone, Mary Anna; Cox, Martha

2008-01-01

This study investigated dopamine receptor genes ("DRD2" and "DRD4") and maternal sensitivity as predictors of infant respiratory sinus arrhythmia (RSA) and RSA reactivity, purported indices of vagal tone and vagal regulation, in a challenge task at 3, 6, and 12 months in 173 infant-mother dyads. Hierarchical linear modeling (HLM) revealed that at…

[Electrical stimulation of the facial nerve with a prognostic function in parotid surgery].

PubMed

García-Losarcos, N; González-Hidalgo, M; Franco-Carcedo, C; Poch-Broto, J

Continuous electromyography during parotidectomies and direct stimulation of the facial nerve as an intraoperative identification technique significantly lower the rate of post-operative morbidity. To determine the usefulness of intra-operative neurophysiological parameters registered by means of electrical stimulation of the facial nerve as values capable of predicting the type of lesion and the functional prognosis. Our sample consisted of a correlative series of 20 cases of monitored parotidectomies. Post-operative facial functioning, type of lesion and its prognosis were compared with the variations in latency/amplitude of the muscle response between two stimulations of the facial nerve before and after resection, as well as in the absence or presence of muscle response to stimulation after resection. All the patients except one presented motor evoked potentials (MEP) to stimulation after resection. There was no facial damage following the operation in 55% of patients and 45% presented some kind of paresis. The 21% drop in the amplitude of the intra-operative MEP and the mean increase in latency of 13.5% correspond to axonal and demyelinating insult, respectively, with a mean recovery time of three and six months. The only case of absence of response to the post-resection stimulation presented permanent paresis. The presence of MEP following resection does not ensure that functioning of the nerve remains undamaged. Nevertheless, it can be considered a piece of data that suggests a lower degree of compromise, if it is present, and a better prognosis. The variations in latency and amplitude of the MEP tend to be intra-operative parameters that indicate the degree of compromise and functional prognosis.

Large Extremity Peripheral Nerve Repair

DTIC Science & Technology

2013-10-01

show that the PTB method can provide fixation strengths approaching that of conventional microsurgery and that the PTB repair is unlikely to be...biomaterial during long periods of recovery associated with large nerve deficit reconstruction and long nerve grafts. As with the human amnion nerve...functional recovery model (SFI, sciatic function index) using PTB/xHAM wrap compared to standard (suture) of care microsurgery . Demonstrated improved nerve

Gait cycle analysis: parameters sensitive for functional evaluation of peripheral nerve recovery in rat hind limbs.

PubMed

Rui, Jing; Runge, M Brett; Spinner, Robert J; Yaszemski, Michael J; Windebank, Anthony J; Wang, Huan

2014-10-01

Video-assisted gait kinetics analysis has been a sensitive method to assess rat sciatic nerve function after injury and repair. However, in conduit repair of sciatic nerve defects, previously reported kinematic measurements failed to be a sensitive indicator because of the inferior recovery and inevitable joint contracture. This study aimed to explore the role of physiotherapy in mitigating joint contracture and to seek motion analysis indices that can sensitively reflect motor function. Data were collected from 26 rats that underwent sciatic nerve transection and conduit repair. Regular postoperative physiotherapy was applied. Parameters regarding step length, phase duration, and ankle angle were acquired and analyzed from video recording of gait kinetics preoperatively and at regular postoperative intervals. Stride length ratio (step length of uninjured foot/step length of injured foot), percent swing of the normal paw (percentage of the total stride duration when the uninjured paw is in the air), propulsion angle (toe-off angle subtracted by midstance angle), and clearance angle (ankle angle change from toe off to midswing) decreased postoperatively comparing with baseline values. The gradual recovery of these measurements had a strong correlation with the post-nerve repair time course. Ankle joint contracture persisted despite rigorous physiotherapy. Parameters acquired from a 2-dimensional motion analysis system, that is, stride length ratio, percent swing of the normal paw, propulsion angle, and clearance angle, could sensitively reflect nerve function impairment and recovery in the rat sciatic nerve conduit repair model despite the existence of joint contractures.

The Heart´s rhythm 'n' blues: Sex differences in circadian variation patterns of vagal activity vary by depressive symptoms in predominantly healthy employees.

PubMed

Jarczok, Marc N; Aguilar-Raab, Corina; Koenig, Julian; Kaess, Michael; Borniger, Jeremy C; Nelson, Randy J; Hall, Martica; Ditzen, Beate; Thayer, Julian F; Fischer, Joachim E

2018-03-15

Successful regulation of emotional states is positively associated to mental health, while difficulties in regulating emotions are negatively associated to overall mental health and in particular associated with anxiety or depression symptoms. A key structure associated to socio-emotional regulatory processes is the central autonomic network. Activity in this structure is associated to vagal activity can be indexed noninvasively and simply by measures of peripheral cardiac autonomic modulations such as heart rate variability. Vagal activity exhibits a circadian variation pattern, with a maximum during nighttime. Depression is known to affect chronobiology. Also, depressive symptoms are known to be associated with decreased resting state vagal activity, but studies investigating the association between circadian variation pattern of vagal activity and depressive symptoms are scarce. We aim to examine these patterns in association to symptom severity of depression using chronobiologic methods. Data from the Manheim Industrial Cohort Studies (MICS) were used. A total of 3,030 predominantly healthy working adults underwent, among others, ambulatory 24-h hear rate-recordings, detailed health examination and online questionnaires and were available for this analysis. The root mean sum of successive differences (RMSSD) was used as an indicator of vagally mediated heart rate variability. Three individual-level cosine function parameters (MESOR, amplitude, acrophase) were estimated to quantify circadian variation pattern. Multivariate linear regression models including important covariates such as age, sex, and lifestyle factors as well as an interaction effect of sex with depressive symptoms were used to estimate the association of circadian variation pattern of vagal activity with depressive symptoms simultaneously. The analysis sample consisted of 20.2% females and an average age 41 with standard deviation of 11 years. Nonparametric bivariate analysis revealed

Functional restoration of diaphragmatic paralysis: an evaluation of phrenic nerve reconstruction.

PubMed

Kaufman, Matthew R; Elkwood, Andrew I; Colicchio, Alan R; CeCe, John; Jarrahy, Reza; Willekes, Lourens J; Rose, Michael I; Brown, David

2014-01-01

Unilateral diaphragmatic paralysis causes respiratory deficits and can occur after iatrogenic or traumatic phrenic nerve injury in the neck or chest. Patients are evaluated using spirometry and imaging studies; however, phrenic nerve conduction studies and electromyography are not widely available or considered; thus, the degree of dysfunction is often unknown. Treatment has been limited to diaphragmatic plication. Phrenic nerve operations to restore diaphragmatic function may broaden therapeutic options. An interventional study of 92 patients with symptomatic diaphragmatic paralysis assigned 68 (based on their clinical condition) to phrenic nerve surgical intervention (PS), 24 to nonsurgical (NS) care, and evaluated a third group of 68 patients (derived from literature review) treated with diaphragmatic plication (DP). Variables for assessment included spirometry, the Short-Form 36-Item survey, electrodiagnostics, and complications. In the PS group, there was an average 13% improvement in forced expiratory volume in 1 second (p < 0.0001) and 14% improvement in forced vital capacity (p < 0.0001), and there was corresponding 17% (p < 0.0001) and 16% (p < 0.0001) improvement in the DP cohort. In the PS and DP groups, the average postoperative values were 71% for forced expiratory volume in 1 second and 73% for forced vital capacity. The PS group demonstrated an average 28% (p < 0.01) improvement in Short-Form 36-Item survey reporting. Electrodiagnostic testing in the PS group revealed a mean 69% (p < 0.05) improvement in conduction latency and a 37% (p < 0.0001) increase in motor amplitude. In the NS group, there was no significant change in Short-Form 36-Item survey or spirometry values. Phrenic nerve operations for functional restoration of the paralyzed diaphragm should be part of the standard treatment algorithm in the management of symptomatic patients with this condition. Assessment of neuromuscular dysfunction can aid in determining the most effective therapy

Radiofrequency thermocoagulation of the thoracic splanchnic nerve in functional abdominal pain syndrome -A case report-.

PubMed

Choi, Ji-Won; Joo, Eun-Young; Lee, Sang-Hyun; Lee, Chul-Joong; Kim, Tae-Hyeong; Sim, Woo-Seok

2011-07-01

The thoracic splanchnic nerve block has been used in managing abdominal pain, especially for pains arising from abdominal cancers. A 27-year-old male patient who had a constant abdominal pain was referred to our clinic for pain management but had no organic disease. The numeric rating scale (NRS) for pain scored 7/10. We applied a diagnostic thoracic splanchnic nerve block under the diagnosis of functional abdominal pain syndrome. Since the block reduced the pain, we applied a radiofrequency thermocoagulation at the T11 and T12 vertebral level. Thereafter, his symptoms improved markedly with pain decreasing to an NRS score of 2-3/10. Hereby, we report a successful management of functional abdominal pain via radiofrequency thermocoagulation of the thoracic splanchnic nerves.

Evaluation of the Predictive Value of Intraoperative Changes in Motor-Evoked Potentials of Caudal Cranial Nerves for the Postoperative Functional Outcome.

PubMed

Kullmann, Marcel; Tatagiba, Marcos; Liebsch, Marina; Feigl, Guenther C

2016-11-01

The predictive value of changes in intraoperatively acquired motor-evoked potentials (MEPs) of the lower cranial nerves (LCN) IX-X (glossopharyngeal-vagus nerve) and CN XII (hypoglossal nerve) on operative outcomes was investigated. MEPs of CN IX-X and CN XII were recorded intraoperatively in 63 patients undergoing surgery of the posterior cranial fossa. We correlated the changes of the MEPs with postoperative nerve function. For CN IX-X, we found a correlation between the amplitude of the MEP ratio and uvula deviation (P = 0.028) and the amplitude duration of the MEP and gag reflex function (P = 0.027). Patients with an MEP ratio of the glossopharyngeal-vagus amplitude ≤1.47 μV had a 3.4 times increased risk of developing a uvula deviation. Patients with a final MEP duration of the CN IX-X ≤11.6 milliseconds had a 3.6 times increased risk for their gag reflex to become extinct. Our study greatly contributes to the current knowledge of intraoperative MEPs as a predictor for postoperative cranial nerve function. We were able to extent previous findings on MEP values of the facial nerve on postoperative nerve function to 3 additional cranial nerves. Finding reliable predictors for postoperative nerve function is of great importance to the overall quality of life for a patient undergoing surgery of the posterior cranial fossa. Copyright © 2016 Elsevier Inc. All rights reserved.

An investigation into the relative merits of pituitary adenylate cyclase-activating polypeptide (PACAP-27) and vasoactive intestinal polypeptide as vagal neuro-transmitters in exocrine pancreas of rats.

PubMed

Wheeler, S; Eardley, J E; McNulty, K F; Sutcliffe, C P; Morrison, J D

1997-07-01

Pancreatic exocrine secretions were collected over 15 min periods and analysed in terms of weight of juice, total HCO3- and total protein in anaesthetized and pithed rats. Pituitary adenylate cyclase-activating polypeptide (PACAP) (i.v.) evoked a serous HCO3- secretion which contained relatively little protein, together with a marked vasodepressor action. The latter was still maximal at lower doses of PACAP, which evoked diminished pancreatic secretions. The effects of PACAP were similar to those evoked by the same dose of VIP and by cervical vagal stimulation, while secretion evoked a much larger secretion of fluid and HCO3-. The time courses of the PACAP-evoked secretions were significantly delayed compared with those of VIP. In the pithed rat, PACAP caused the same level of pancreatic secretions as in the anaesthetized rat, though this was now accompanied by a substantial pressor response which was blocked by phentolamine or prazosin, indicating that it was alpha 1-adrenoceptor mediated. VIP caused a depressor response in the pithed rat, as well as the same level of pancreatic secretions as in the anaesthetized rat. The putative VIP antagonist [Lys1,Pro25,Arg3,4,Tyr6]-VIP (abbreviated as VIPi) caused a selective and significant reduction in the HCO3- secretion evoked by VIP and blocked the vasodepressor response caused by VIP. By contrast, VIPi did not antagonize either the secretory or vasodepressor actions of PACAP. Unilateral electrical stimulation of the cervical vagus nerve evoked significant increases in the weight of juice, total protein and total HCO3- secreted. When preceded by injection of VIPi, vagally evoked secretions were unchanged in terms of weight of juice and total protein but had a significantly reduced HCO3- content. These results are consistent with the release of VIP, though not PACAP, as a vagal neurotransmitter in the exocrine pancreas.

[Using infrared thermal asymmetry analysis for objective assessment of the lesion of facial nerve function].

PubMed

Liu, Xu-long; Hong, Wen-xue; Song, Jia-lin; Wu, Zhen-ying

2012-03-01

The skin temperature distribution of a healthy human body exhibits a contralateral symmetry. Some lesions of facial nerve function are associated with an alteration of the thermal distribution of the human body. Since the dissipation of heat through the skin occurs for the most part in the form of infrared radiation, infrared thermography is the method of choice to capture the alteration of the infrared thermal distribution. This paper presents a new method of analysis of the thermal asymmetry named effective thermal area ratio, which is a product of two variables. The first variable is mean temperature difference between the specific facial region and its contralateral region. The second variable is a ratio, which is equal to the area of the abnormal region divided by the total area. Using this new method, we performed a controlled trial to assess the facial nerve function of the healthy subjects and the patients with Bell's palsy respectively. The results show: that the mean specificity and sensitivity of this method are 0.90 and 0.87 respectively, improved by 7% and 26% compared with conventional methods. Spearman correlation coefficient between effective thermal area ratio and the degree of facial nerve function is an average of 0.664. Hence, concerning the diagnosis and assessment of facial nerve function, infrared thermography is a powerful tool; while the effective ther mal area ratio is an efficient clinical indicator.

Development of the intrinsic and extrinsic innervation of the gut.

PubMed

Uesaka, Toshihiro; Young, Heather M; Pachnis, Vassilis; Enomoto, Hideki

2016-09-15

The gastrointestinal (GI) tract is innervated by intrinsic enteric neurons and by extrinsic efferent and afferent nerves. The enteric (intrinsic) nervous system (ENS) in most regions of the gut consists of two main ganglionated layers; myenteric and submucosal ganglia, containing numerous types of enteric neurons and glial cells. Axons arising from the ENS and from extrinsic neurons innervate most layers of the gut wall and regulate many gut functions. The majority of ENS cells are derived from vagal neural crest cells (NCCs), which proliferate, colonize the entire gut, and first populate the myenteric region. After gut colonization by vagal NCCs, the extrinsic nerve fibers reach the GI tract, and Schwann cell precursors (SCPs) enter the gut along the extrinsic nerves. Furthermore, a subpopulation of cells in myenteric ganglia undergoes a radial (inward) migration to form the submucosal plexus, and the intrinsic and extrinsic innervation to the mucosal region develops. Here, we focus on recent progress in understanding the developmental processes that occur after the gut is colonized by vagal ENS precursors, and provide an up-to-date overview of molecular mechanisms regulating the development of the intrinsic and extrinsic innervation of the GI tract. Copyright © 2016 Elsevier Inc. All rights reserved.

Neural control of the kidney: functionally specific renal sympathetic nerve fibers.

PubMed

DiBona, G F

2000-11-01

The sympathetic nervous system provides differentiated regulation of the functions of various organs. This differentiated regulation occurs via mechanisms that operate at multiple sites within the classic reflex arc: peripherally at the level of afferent input stimuli to various reflex pathways, centrally at the level of interconnections between various central neuron pools, and peripherally at the level of efferent fibers targeted to various effectors within the organ. In the kidney, increased renal sympathetic nerve activity regulates the functions of the intrarenal effectors: the tubules, the blood vessels, and the juxtaglomerular granular cells. This enables a physiologically appropriate coordination between the circulatory, filtration, reabsorptive, excretory, and renin secretory contributions to overall renal function. Anatomically, each of these effectors has a dual pattern of innervation consisting of a specific and selective innervation by unmyelinated slowly conducting C-type renal sympathetic nerve fibers in addition to an innervation that is shared among all the effectors. This arrangement permits the maximum flexibility in the coordination of physiologically appropriate responses of the tubules, the blood vessels, and the juxtaglomerular granular cells to a variety of homeostatic requirements.

Sex differences in the associations between vagal reactivity and oppositional defiant disorder symptoms.

PubMed

Vidal-Ribas, Pablo; Pickles, Andrew; Tibu, Florin; Sharp, Helen; Hill, Jonathan

2017-09-01

Vagal reactivity to stress in children has been associated with future psychiatric outcomes. However, results have been mixed possibly because these effects are in opposite direction in boys and girls. These sex differences are relevant in the context of development of psychopathology, whereby the rates of psychiatric disorders differ by sex. In this study, we aimed to examine the association between vagal reactivity, assessed as a reduction in respiratory sinus arrhythmia (RSA) in response to a challenge, and the development of future oppositional defiant disorder (ODD) symptoms in boys and girls. In addition, we examine the specific associations with ODD symptom dimensions, named irritability and headstrong. We hypothesized that increased vagal reactivity was associated with increased ODD symptoms in girls and a reduction in ODD symptoms in boys. Participants were members of the Wirral Child Health and Development Study, a prospective epidemiological longitudinal study of 1,233 first-time mothers recruited at 20 weeks' gestation. RSA during four nonstressful and one stressful (still-face) procedures was assessed when children were aged 29 weeks in a sample stratified by adversity (n = 270). Maternal reports of ODD symptoms were collected when children were 2.5 years old (n = 253), 3.5 years old (n = 826), and 5 years old (n = 770). Structural equation modeling (SEM) was employed to test our hypotheses. There was a significant sex difference in the prediction of ODD symptoms due to the opposite directionality in which increasing vagal reactivity was associated with an increase in ODD symptoms in girls and a reduction of ODD symptoms in boys. This Sex by Vagal reactivity interaction was common for both ODD dimensions, with no sex by dimension-specific associations. Physiological reactivity to a stressful situation predicts differently ODD symptoms in boys and girls very early in life, with no difference across irritability and headstrong components

The Effect of Memantine on Functional Recovery of the Sciatic Nerve Crush Injury in Rats.

PubMed

Ghayour, Mohammad-Bagher; Abdolmaleki, Arash; Behnam-Rassouli, Morteza

2017-01-01

Following severe peripheral nerve injury (PNI), regeneration is often insufficient and functional recovery is incomplete. In this regard, glutamate N-methyl-D-aspartate (NMDA) receptor antagonist such as Memantine have been shown to have neuroprotective effects. We evaluated the effects of Memantine against sciatic nerve crush injury in male Wistar Rats. Memantine or vehicle was given parenteraly to rats for 7 days postoperative. In Memantine treatment groups, a single dose of agent (5 and 10 mg/kg) was administered daily. The control group was given vehicle in the same manner. The rats were subjected to crush injury in the left sciatic nerve with non-serrated clamp for 30 seconds. Behavioural, electrophysiological and morphological alterations were evaluated during the experimental period. Results showed that Memantine has no significant effect on regeneration process rate and functional recovery quality. In the sciatic functional index (SFI) test no significant difference was observed between Memantine treatment groups (5 and 10 mg/ kg) at any week. Since the major neuroprotective effect of Memantine is due to its protective activity against NMDA receptormediated excitotoxicity, it seems that glutamate excitotoxicity is less important in motor impairment due to sciatic nerve crush injury. It is clear that more research is needed to confirm these findings.

Vagus nerve stimulation as a potential adjuvant to behavioral therapy for autism and other neurodevelopmental disorders.

PubMed

Engineer, Crystal T; Hays, Seth A; Kilgard, Michael P

2017-01-01

Many children with autism and other neurodevelopmental disorders undergo expensive, time-consuming behavioral interventions that often yield only modest improvements. The development of adjunctive interventions that can increase the benefit of rehabilitation therapies is essential in order to improve the lives of individuals with neurodevelopmental disorders. Vagus nerve stimulation (VNS) is an FDA approved therapy that is safe and effective in reducing seizure frequency and duration in individuals with epilepsy. Individuals with neurodevelopmental disorders often exhibit decreased vagal tone, and studies indicate that VNS can be used to overcome an insufficient vagal response. Multiple studies have also documented significant improvements in quality of life after VNS therapy in individuals with neurodevelopmental disorders. Moreover, recent findings indicate that VNS significantly enhances the benefits of rehabilitative training in animal models and patients, leading to greater recovery in a variety of neurological diseases. Here, we review these findings and provide a discussion of how VNS paired with rehabilitation may yield benefits in the context of neurodevelopmental disorders. VNS paired with behavioral therapy may represent a potential new approach to enhance rehabilitation that could significantly improve the outcomes of individuals with neurodevelopmental disorders.

Vagal stimulation targets select populations of intrinsic cardiac neurons to control neurally induced atrial fibrillation

PubMed Central

Salavatian, Siamak; Beaumont, Eric; Longpré, Jean-Philippe; Armour, J. Andrew; Vinet, Alain; Jacquemet, Vincent; Shivkumar, Kalyanam

2016-01-01

Mediastinal nerve stimulation (MNS) reproducibly evokes atrial fibrillation (AF) by excessive and heterogeneous activation of intrinsic cardiac (IC) neurons. This study evaluated whether preemptive vagus nerve stimulation (VNS) impacts MNS-induced evoked changes in IC neural network activity to thereby alter susceptibility to AF. IC neuronal activity in the right atrial ganglionated plexus was directly recorded in anesthetized canines (n = 8) using a linear microelectrode array concomitant with right atrial electrical activity in response to: 1) epicardial touch or great vessel occlusion vs. 2) stellate or vagal stimulation. From these stressors, post hoc analysis (based on the Skellam distribution) defined IC neurons so recorded as afferent, efferent, or convergent (afferent and efferent inputs) local circuit neurons (LCN). The capacity of right-sided MNS to modify IC activity in the induction of AF was determined before and after preemptive right (RCV)- vs. left (LCV)-sided VNS (15 Hz, 500 μs; 1.2× bradycardia threshold). Neuronal (n = 89) activity at baseline (0.11 ± 0.29 Hz) increased during MNS-induced AF (0.51 ± 1.30 Hz; P < 0.001). Convergent LCNs were preferentially activated by MNS. Preemptive RCV reduced MNS-induced changes in LCN activity (by 70%) while mitigating MNS-induced AF (by 75%). Preemptive LCV reduced LCN activity by 60% while mitigating AF potential by 40%. IC neuronal synchrony increased during neurally induced AF, a local neural network response mitigated by preemptive VNS. These antiarrhythmic effects persisted post-VNS for, on average, 26 min. In conclusion, VNS preferentially targets convergent LCNs and their interactive coherence to mitigate the potential for neurally induced AF. The antiarrhythmic properties imposed by VNS exhibit memory. PMID:27591222

Mechanism to preserve phrenic nerve function during photosensitization reaction: drug uptake and photosensitization reaction effect on electric propagation

NASA Astrophysics Data System (ADS)

Takahashi, Haruka; Hamada, Risa; Ogawa, Emiyu; Arai, Tsunenori

2018-02-01

To study a mechanism of phrenic nerve preservation phenomena during a photosensitization reaction, we investigated an uptake of talaporfin sodium and photosensitization reaction effect on an electric propagation. Right phrenic nerve was completely preserved after superior vena cava isolations using the photosensitization reaction in canine animal experiments, in spite of adjacent myocardium was electrically blocked. We predicted that low drug uptake and/or low photosensitization reaction effect on the nerve might be a mechanism of that phenomena. To investigate uptake to various nerve tissue, a healthy extracted crayfish ventral nerve cord and an extracted porcine phrenic nerve were immersed in 20 μg/ml talaporfin sodium solution for 0-240 min. The mean talaporfin sodium fluorescence brightness increased depending on the immersion time. This brightness saturated around the immersion time of 120 min. We found that talaporfin sodium uptake inside the perineurium which directly related to the electric propagation function was lower than that of outside in the porcine phrenic nerve. To investigate photosensitization reaction effect on electric propagation, the crayfish nerve was immersed into the same solution for 15 min and irradiated by a 663 nm laser light with 120 mW/cm2. Since we found the action potential disappeared when the irradiation time was 25-65 s, we consider that the crayfish nerve does not tolerant to the photosensitization reaction on electric propagation function at atmospheric pressure. From these results, we think that the low uptake of talaporfin sodium inside the perineurium and low oxygen partial pressure of nerve might be the possible mechanism to preserve phrenic nerve in vivo.

Axillary nerve injury associated with sports.

PubMed

Lee, Sangkook; Saetia, Kriangsak; Saha, Suparna; Kline, David G; Kim, Daniel H

2011-11-01

The aim of this retrospective study was to present and investigate axillary nerve injuries associated with sports. This study retrospectively reviewed 26 axillary nerve injuries associated with sports between the years 1985 and 2010. Preoperative status of the axillary nerve was evaluated by using the Louisiana State University Health Science Center (LSUHSC) grading system published by the senior authors. Intraoperative nerve action potential recordings were performed to check nerve conduction and assess the possibility of resection. Neurolysis, suture, and nerve grafts were used for the surgical repair of the injured nerves. In 9 patients with partial loss of function and 3 with complete loss, neurolysis based on nerve action potential recordings was the primary treatment. Two patients with complete loss of function were treated with resection and suturing and 12 with resection and nerve grafting. The minimum follow-up period was 16 months (mean 20 months). The injuries were associated with the following sports: skiing (12 cases), football (5), rugby (2), baseball (2), ice hockey (2), soccer (1), weightlifting (1), and wrestling (1). Functional recovery was excellent. Neurolysis was performed in 9 cases, resulting in an average functional recovery of LSUHSC Grade 4.2. Recovery with graft repairs averaged LSUHSC Grade 3 or better in 11 of 12 cases Surgical repair can restore useful deltoid function in patients with sports-associated axillary nerve injuries, even in cases of severe stretch-contusion injury.

Thermographic evaluation of hind paw skin temperature and functional recovery of locomotion after sciatic nerve crush in rats

PubMed Central

Z. Sacharuk, Viviane; A. Lovatel, Gisele; Ilha, Jocemar; Marcuzzo, Simone; Severo do Pinho, Alexandre; L. Xavier, Léder; A. Zaro, Milton; Achaval, Matilde

2011-01-01

INTRODUCTION: Peripheral nerves are often damaged by direct mechanical injury, diseases, and tumors. The peripheral nerve injuries that result from these conditions can lead to a partial or complete loss of motor, sensory, and autonomic functions, which in turn are related to changes in skin temperature, in the involved segments of the body. The aim of this study was to evaluate the changes in hind paw skin temperature after sciatic nerve crush in rats in an attempt to determine whether changes in skin temperature correlate with the functional recovery of locomotion. METHODS: Wistar rats were divided into three groups: control (n = 7), sham (n = 25), and crush (n = 25). All groups were subjected to thermographic, functional, and histological assessments. RESULTS: ΔT in the crush group was different from the control and sham groups at the 1st, 3rd and 7rd postoperative days (p<0.05). The functional recovery from the crush group returned to normal values between the 3rd and 4th week post-injury, and morphological analysis of the nerve revealed incomplete regeneration at the 4th week after injury. DISCUSSION: This study is the first demonstration that sciatic nerve crush in rats induces an increase in hind paw skin temperature and that skin temperature changes do not correlate closely with functional recovery PMID:21876984

Architecture of Vagal Motor Units Controlling Striated Muscle of Esophagus: Peripheral Elements Patterning Peristalsis?

PubMed Central

Powley, Terry L.; Mittal, Ravinder K.; Baronowsky, Elizabeth A.; Hudson, Cherie N.; Martin, Felecia N.; McAdams, Jennifer L.; Mason, Jacqueline K.; Phillips, Robert J.

2013-01-01

Little is known about the architecture of the vagal motor units that control esophageal striated muscle, in spite of the fact that these units are necessary, and responsible, for peristalsis. The present experiment was designed to characterize the motor neuron projection fields and terminal arbors forming esophageal motor units. Nucleus ambiguus compact formation neurons of the rat were labeled by bilateral intracranial injections of the anterograde tracer dextran biotin. After tracer transport, thoracic and abdominal esophagi were removed and prepared as whole mounts of muscle wall without mucosa or submucosa. Labeled terminal arbors of individual vagal motor neurons (n = 78) in the esophageal wall were inventoried, digitized and analyzed morphometrically. The size of individual vagal motor units innervating striated muscle, throughout thoracic and abdominal esophagus, averaged 52 endplates per motor neuron, a value indicative of fine motor control. A majority (77%) of the motor terminal arbors also issued one or more collateral branches that contacted neurons, including nitric oxide synthase-positive neurons, of local myenteric ganglia. Individual motor neuron terminal arbors co-innervated, or supplied endplates in tandem to, both longitudinal and circular muscle fibers in roughly similar proportions (i.e., two endplates to longitudinal for every three endplates to circular fibers). Both the observation that vagal motor unit collaterals project to myenteric ganglia and the fact that individual motor units co-innervate longitudinal and circular muscle layers are consistent with the hypothesis that elements contributing to peristaltic programming inhere, or are “hardwired,” in the peripheral architecture of esophageal motor units. PMID:24044976

Gastric relaxation induced by hyperglycemia is mediated by vagal afferent pathways in the rat

PubMed Central

Zhou, Shi-Yi; Lu, Yuan-Xu; Owyang, Chung

2011-01-01

Hyperglycemia has a profound effect on gastric motility. However, little is known about site and mechanism that sense alteration in blood glucose level. The identification of glucose-sensing neurons in the nodose ganglia led us to hypothesize that hyperglycemia acts through vagal afferent pathways to inhibit gastric motility. With the use of a glucose clamp rat model, we showed that glucose decreased intragastric pressure in a dose-dependent manner. In contrast to intravenous infusion of glucose, intracisternal injection of glucose at 250 and 500 mg dL−1 had little effect on intragastric pressure. Pretreatment with hexamethonium, as well as truncal vagotomy, abolished the gastric motor responses to hyperglycemia (250 mg dL−1), and perivagal and gastroduodenal applications of capsaicin significantly reduced the gastric responses to hyperglycemia. In contrast, hyperglycemia had no effect on the gastric contraction induced by electrical field stimulation or carbachol (10−5 M). To rule out involvement of serotonergic pathways, we showed that neither granisetron (5-HT3 antagonist, 0.5 g kg−1) nor pharmacological depletion of 5-HT using p-chlorophenylalanine (5-HT synthesis inhibitor) affected gastric relaxation induced by hyperglycemia. Lastly, NG-nitro-L-arginine methyl ester (l-NAME) and a VIP antagonist each partially reduced gastric relaxation induced by hyperglycemia, and in combination, completely abolished gastric responses. In conclusion, hyperglycemia inhibits gastric motility through a capsaicin-sensitive vagal afferent pathway originating from the gastroduodenal mucosa. Hyperglycemia stimulates vagal afferents, which, in turn, activate vagal efferent cholinergic pathways synapsing with intragastric nitric oxide- and VIP-containing neurons to mediate gastric relaxation. PMID:18356537

Architecture of vagal motor units controlling striated muscle of esophagus: peripheral elements patterning peristalsis?

PubMed

Powley, Terry L; Mittal, Ravinder K; Baronowsky, Elizabeth A; Hudson, Cherie N; Martin, Felecia N; McAdams, Jennifer L; Mason, Jacqueline K; Phillips, Robert J

2013-12-01

Little is known about the architecture of the vagal motor units that control esophageal striated muscle, in spite of the fact that these units are necessary, and responsible, for peristalsis. The present experiment was designed to characterize the motor neuron projection fields and terminal arbors forming esophageal motor units. Nucleus ambiguus compact formation neurons of the rat were labeled by bilateral intracranial injections of the anterograde tracer dextran biotin. After tracer transport, thoracic and abdominal esophagi were removed and prepared as whole mounts of muscle wall without mucosa or submucosa. Labeled terminal arbors of individual vagal motor neurons (n=78) in the esophageal wall were inventoried, digitized and analyzed morphometrically. The size of individual vagal motor units innervating striated muscle, throughout thoracic and abdominal esophagus, averaged 52 endplates per motor neuron, a value indicative of fine motor control. A majority (77%) of the motor terminal arbors also issued one or more collateral branches that contacted neurons, including nitric oxide synthase-positive neurons, of local myenteric ganglia. Individual motor neuron terminal arbors co-innervated, or supplied endplates in tandem to, both longitudinal and circular muscle fibers in roughly similar proportions (i.e., two endplates to longitudinal for every three endplates to circular fibers). Both the observation that vagal motor unit collaterals project to myenteric ganglia and the fact that individual motor units co-innervate longitudinal and circular muscle layers are consistent with the hypothesis that elements contributing to peristaltic programming inhere, or are "hardwired," in the peripheral architecture of esophageal motor units. © 2013.

[Nerve sparing techniques in deep endometriosis surgery to prevent urinary or digestive functional disorders: Techniques and results: CNGOF-HAS Endometriosis Guidelines].

PubMed

Rabischong, B; Botchorishvili, R; Bourdel, N; Curinier, S; Campagne-Loiseau, S; Pouly, J L; Canis, M

2018-03-01

To evaluate the feasibility and functional urinary and digestive results of nerve sparing techniques in endometriosis surgery. A research on the medline/pubmed database using specific keywords (nerve sparing, endometriosis, pelvic nerves) identified 7 publications among about 50 whose purpose was to describe the feasibility, the techniques and the functional results of nerve preservation in this indication. Among them there are: 2 uncontrolled retrospective studies, 3 prospective non-randomized studies, a meta-analysis and a review of the literature. Nerve preservation requires a perfect knowledge of the anatomy of the pelvic autonomic system. The laparoscopic approach is preferred by the different authors due to its anatomical advantage. The feasibility of this technique seems to be demonstrated despite certain limitations in the different studies and depending of the retroperitoneal extension of the lesions. When feasible, it is likely to significantly improve postoperative urinary function (urinary retention) compared to a conventional technique. It is observed no difference regarding digestive function. Nerve sparing in this indication is a technique the feasibility of which has been demonstrated and is subject to the topography and extent of the disease. In the absence of invasion or entrapment of pelvic autonomic nerves by endometriosis, this technique improves postoperative voiding function (NP3). During pelvic surgery for endometriosis, it is recommended to identify and preserve autonomic pelvic nerves whenever possible (GradeC). Copyright © 2018. Published by Elsevier Masson SAS.

AIRWAY HYPERRESPONSIVENESS IN MICE FOLLOWING ANTIGEN AND PARTICULATE MATTER EXPOSURE IS VAGALLY MEDIATED

EPA Science Inventory

Sensory nerves within the airways can initiate a variety of protective reflexes. We hypothesized that insults such as exposure to antigen and particulate matter (PM) might dysregulate airway sensory nerve function, thereby contributing to enhanced airway inflammation and hyperre...

The Kölliker-Fuse nucleus: a review of animal studies and the implications for cranial nerve function in humans.

PubMed

Browaldh, Nanna; Bautista, Tara G; Dutschmann, Mathias; Berkowitz, Robert G

2016-11-01

To review the scientific literature on the relationship between Kölliker-Fuse nucleus (KF) and cranial nerve function in animal models, with view to evaluating the potential role of KF maturation in explaining age-related normal physiologic parameters and developmental and acquired impairment of cranial nerve function in humans. Medical databases (Medline and PubMed). Studies investigating evidence of KF activity responsible for a specific cranial nerve function that were based on manipulation of KF activity or the use of neural markers were included. Twenty studies were identified that involved the trigeminal (6 studies), vagus (9), and hypoglossal nerves (5). These pertained specifically to a role of the KF in mediating the dive reflex, laryngeal adductor control, swallowing function and upper airway tone. The KF acts as a mediator of a number of important functions that relate primarily to laryngeal closure, upper airway tone and swallowing. These areas are characterized by a variety of disorders that may present to the otolaryngologist, and hence the importance of understanding the role played by the KF in maintaining normal function.

Accentuated antagonism in vagal heart rate control mediated through muscarinic potassium channels.

PubMed

Mizuno, Masaki; Kamiya, Atsunori; Kawada, Toru; Miyamoto, Tadayoshi; Shimizu, Shuji; Shishido, Toshiaki; Sugimachi, Masaru

2008-12-01

Although muscarinic K(+) (K(ACh)) channels contribute to a rapid heart rate (HR) response to vagal stimulation, whether background sympathetic tone affects the HR control via the K(ACh)channels remains to be elucidated. In seven anesthetized rabbits with sinoaortic denervation and vagotomy, we estimated the dynamic transfer function of the HR response by using random binary vagal stimulation (0-10 Hz). Tertiapin, a selective K(ACh) channel blocker, decreased the dynamic gain (to 2.3+/- 0.9 beats.min(-1).Hz(-1), from 4.6+/- 1.1, P < 0.01, mean+/- SD) and the corner frequency (to 0.05+/- 0.01 Hz, from 0.26+/- 0.04, P < 0.01). Under 5 Hz tonic cardiac sympathetic stimulation (CSS), tertiapin decreased the dynamic gain (to 3.6+/- 1.0 beats.min(-1).Hz(-1), from 7.3+/- 1.1, P < 0.01) and the corner frequency (to 0.06+/- 0.02 Hz, from 0.23+/- 0.06, P < 0.01). Two-way analysis of variance indicated significant interaction between the tertiapin and CSS effects on the dynamic gain. In contrast, no significant interactions were observed between the tertiapin and CSS effects on the corner frequency and the lag time. In conclusion, although a cyclic AMP-dependent mechanism has been well established, an accentuated antagonism also occurred in the direct effect of ACh via the K(ACh) channels. The rapidity of the HR response obtained by the K(ACh) channel pathway was robust during the accentuated antagonism.

Effect of in situ delivery of acetyl-L-carnitine on peripheral nerve regeneration and functional recovery in transected sciatic nerve in rat.

PubMed

Farahpour, Mohammad Reza; Ghayour, Sina Jangkhahe

2014-12-01

The repair of peripheral nerve injuries is still one of the most challenging tasks and concerns in neurosurgery, plastic and orthopedic surgery. Effect of acetyl-L-carnitine (ALC) loaded chitosan conduit as an in situ delivery system of ALC in bridging the defects was studied using a rat sciatic nerve regeneration model. A 10-mm sciatic nerve defect was bridged using a chitosan conduit (CHIT/ALC) filled with 10 μL ALC (100 ng/mL). In control group (CHIT), the conduit was filled with the same volume of the phosphate buffered solution. The regenerated fibers were studied 4, 8, 12 and 16 weeks after surgery. The functional and electrophysiological studies confirmed faster recovery of the regenerated axons in ALC treated than control group (P < 0.05). The mean ratios of gastrocnemius muscles weight were measured. There was statistically significant difference between the muscle weight ratios of CHIT/ALC and CHIT groups (P<0.05). Morphometric indices of regenerated fibers showed number and diameter of the myelinated fibers in CHIT/ALC were significantly higher than in control group. In immuohistochemistry, the location of reactions to S-100 in CHIT/ALC was clearly more positive than CHIT group. ALC when loaded in a chitosan conduit resulted in improvement of functional recovery and quantitative morphometric indices of sciatic nerve. Copyright © 2014 Surgical Associates Ltd. Published by Elsevier Ltd. All rights reserved.

Fate of combat nerve injury.

PubMed

Beltran, Michael J; Burns, Travis C; Eckel, Tobin T; Potter, Benjamin K; Wenke, Joseph C; Hsu, Joseph R

2012-11-01

Assess a cohort of combat-related type III open tibia fractures with peripheral nerve injury to determine the injury mechanism and likelihood for recovery or improvement in nerve function. Retrospective study. Three military medical centers. Out of a study cohort of 213 type III open tibia fractures, 32 fractures (in 32 patients) with a total of 43 peripheral nerve injuries (peroneal or tibial) distal to the popliteal fossa met inclusion criteria and were available for follow-up at an average of 20 months (range, 2-48 months). Clinical assessment of motor and sensory nerve improvement. There was a 22% incidence of peripheral nerve injury in the study cohort. At an average follow-up of 20 months (range, 2-48 months), 89% of injured motor nerves were functional, whereas the injured sensory nerves had function in 93%. Fifty percent and 27% of motor and sensory injuries demonstrated improvement, respectively (P = 0.043). With the numbers available, there was no difference in motor or sensory improvement based on mechanism of injury, fracture severity or location, soft tissue injury, or specific nerve injured. In the subset of patients with an initially impaired sensory examination, full improvement was related to fracture location (P = 0.0164). Type III open tibia fractures sustained in combat are associated with a 22% incidence of peripheral nerve injury, and the majority are due to multiple projectile penetrating injury. Despite the severe nature of these injuries, the vast majority of patients had a functional nerve status by an average of 2-year follow-up. Based on these findings, discussions regarding limb salvage and amputation should not be overly influenced by the patient's peripheral nerve status. Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Nervous kidney. Interaction between renal sympathetic nerves and the renin-angiotensin system in the control of renal function.

PubMed

DiBona, G F

2000-12-01

Increases in renal sympathetic nerve activity regulate the functions of the nephron, the vasculature, and the renin-containing juxtaglomerular granular cells. Because increased activity of the renin-angiotensin system can also influence nephron and vascular function, it is important to understand the interactions between the renal sympathetic nerves and the renin-angiotensin system in the control of renal function. These interactions can be intrarenal, for example, the direct (by specific innervation) and indirect (by angiotensin II) contributions of increased renal sympathetic nerve activity to the regulation of renal function. The effects of increased renal sympathetic nerve activity on renal function are attenuated when the activity of the renin-angiotensin system is suppressed or antagonized with ACE inhibitors or angiotensin II-type AT(1)-receptor antagonists. The effects of intrarenal administration of angiotensin II are attenuated after renal denervation. These interactions can also be extrarenal, for example, in the central nervous system, wherein renal sympathetic nerve activity and its arterial baroreflex control are modulated by changes in activity of the renin-angiotensin system. In addition to the circumventricular organs, whose permeable blood-brain barrier permits interactions with circulating angiotensin II, there are interactions at sites behind the blood-brain barrier that depend on the influence of local angiotensin II. The responses to central administration of angiotensin II-type AT(1)-receptor antagonists into the ventricular system or microinjected into the rostral ventrolateral medulla are modulated by changes in activity of the renin-angiotensin system produced by physiological changes in dietary sodium intake. Similar modulation is observed in pathophysiological models wherein activity of both the renin-angiotensin and sympathetic nervous systems is increased (eg, congestive heart failure). Thus, both renal and extrarenal sites of

Diet-driven microbiota dysbiosis is associated with vagal remodeling and obesity.

PubMed

Sen, Tanusree; Cawthon, Carolina R; Ihde, Benjamin Thomas; Hajnal, Andras; DiLorenzo, Patricia M; de La Serre, Claire B; Czaja, Krzysztof

2017-05-01

Obesity is one of the major health issues in the United States. Consumption of diets rich in energy, notably from fats and sugars (high-fat/high-sugar diet: HF/HSD) is linked to the development of obesity and a popular dietary approach for weight loss is to reduce fat intake. Obesity research traditionally uses low and high fat diets and there has been limited investigation of the potential detrimental effects of a low-fat/high-sugar diet (LF/HSD) on body fat accumulation and health. Therefore, in the present study, we investigated the effects of HF/HSD and LF/HSD on microbiota composition, gut inflammation, gut-brain vagal communication and body fat accumulation. Specifically, we tested the hypothesis that LF/HSD changes the gut microbiota, induces gut inflammation and alters vagal gut-brain communication, associated with increased body fat accumulation. Sprague-Dawley rats were fed an HF/HSD, LF/HSD or control low-fat/low-sugar diet (LF/LSD) for 4weeks. Body weight, caloric intake, and body composition were monitored daily and fecal samples were collected at baseline, 1, 6 and 27days after the dietary switch. After four weeks, blood and tissues (gut, brain, liver and nodose ganglia) were sampled. Both HF/HSD and LF/HSD-fed rats displayed significant increases in body weight and body fat compared to LF/LSD-fed rats. 16S rRNA sequencing showed that both HF/HSD and LF/HSD-fed animals exhibited gut microbiota dysbiosis characterized by an overall decrease in bacterial diversity and an increase in Firmicutes/Bacteriodetes ratio. Dysbiosis was typified by a bloom in Clostridia and Bacilli and a marked decrease in Lactobacillus spp. LF/HSD-fed animals showed a specific increase in Sutterella and Bilophila, both Proteobacteria, abundances of which have been associated with liver damage. Expression of pro-inflammatory cytokines, such as IL-6, IL-1β and TNFα, was upregulated in the cecum while levels of tight junction protein occludin were downregulated in both HF

Reconstruction of facial nerve injuries in children.

PubMed

Fattah, Adel; Borschel, Gregory H; Zuker, Ron M

2011-05-01

Facial nerve trauma is uncommon in children, and many spontaneously recover some function; nonetheless, loss of facial nerve activity leads to functional impairment of ocular and oral sphincters and nasal orifice. In many cases, the impediment posed by facial asymmetry and reduced mimetic function more significantly affects the child's psychosocial interactions. As such, reconstruction of the facial nerve affords great benefits in quality of life. The therapeutic strategy is dependent on numerous factors, including the cause of facial nerve injury, the deficit, the prognosis for recovery, and the time elapsed since the injury. The options for treatment include a diverse range of surgical techniques including static lifts and slings, nerve repairs, nerve grafts and nerve transfers, regional, and microvascular free muscle transfer. We review our strategies for addressing facial nerve injuries in children.

Functional and structural microanatomy of the fetal sciatic nerve.

PubMed

Creze, Maud; Zaitouna, Mazen; Krystel, Nyangoh Timoh; Diallo, Djibril; Lebacle, Cédric; Bellin, Marie-France; Ducreux, Denis; Benoit, Gérard; Bessede, Thomas

2017-10-01

The ultrastructure of a nerve has implications for surgical nerve repair. The aim of our study was to characterize the fascicular versus fibrillar anatomy and the autonomic versus somatic nature of the fetal sciatic nerve (SN). Immunohistochemistry for vesicular acetylcholine transporter, tyrosine hydroxylase, and peripheral myelin protein 22 was performed to identify cholinergic, adrenergic, and somatic axons, respectively, in the human fetal SN. Two-dimensional (2D) analysis and 3D reconstructions were performed. The fetal SN is composed of one-third stromal tissue and two-thirds neural tissue. Autonomic fibers are predominant over somatic fibers within the neural tissue. The distribution of somatic fibers is initially random, but then become topographically organized after intra- and interfascicular rearrangements have occurred within the nerve. The fetal model presents limitations but enables illustration of the nature of the nerve fibers and the 3D fascicular anatomy of the SN. Muscle Nerve 56: 787-796, 2017. © 2017 Wiley Periodicals, Inc.

Function and morphology correlates of rectal nerve mechanoreceptors innervating the guinea pig internal anal sphincter.

PubMed

Lynn, P A; Brookes, S J H

2011-01-01

Mechanoreceptors to the internal anal sphincter (IAS) contribute to continence and normal defecation, yet relatively little is known about their function or morphology. We investigated the function and structure of mechanoreceptors to the guinea pig IAS. Extracellular recordings from rectal nerve branches to the IAS in vitro, combined with anterograde labeling of recorded nerve trunks, were used to characterize extrinsic afferent nerve endings activated by circumferential distension. Slowly adapting, stretch-sensitive afferents were recorded in rectal nerves to the IAS. Ten of 11 were silent under basal conditions and responded to circumferential stretch in a saturating linear manner. Rectal nerve afferents responded to compression with von Frey hairs with low thresholds (0.3-0.5 mN) and 3.4 ± 0.5 discrete, elongated mechanosensitive fields of innervation aligned parallel to circular muscle bundles (length = 62 ± 16 mm, n = 10). Anterogradely labeled rectal nerve axons typically passed through sparse irregular myenteric ganglia adjacent to the IAS, before ending in extensive varicose arrays within the circular muscle and, to a lesser extent, the longitudinal muscle overlying the IAS. Few (8%) IAS myenteric ganglia contained intraganglionic laminar endings. In eight preparations, mechanotransduction sites were mapped in combination with successful anterograde fills. Mechanotransduction sites were strongly associated with extensive fine varicose arrays within the circular muscle (P < 0.05), and not with any other neural structures. Mechanotransduction sites for low-threshold, slowly adapting mechanoreceptors innervating the IAS are likely to correspond to extensive fine varicose arrays within the circular muscle. © 2010 Blackwell Publishing Ltd.

"Long-term stability of stimulating spiral nerve cuff electrodes on human peripheral nerves".

PubMed

Christie, Breanne P; Freeberg, Max; Memberg, William D; Pinault, Gilles J C; Hoyen, Harry A; Tyler, Dustin J; Triolo, Ronald J

2017-07-11

Electrical stimulation of the peripheral nerves has been shown to be effective in restoring sensory and motor functions in the lower and upper extremities. This neural stimulation can be applied via non-penetrating spiral nerve cuff electrodes, though minimal information has been published regarding their long-term performance for multiple years after implantation. Since 2005, 14 human volunteers with cervical or thoracic spinal cord injuries, or upper limb amputation, were chronically implanted with a total of 50 spiral nerve cuff electrodes on 10 different nerves (mean time post-implant 6.7 ± 3.1 years). The primary outcome measures utilized in this study were muscle recruitment curves, charge thresholds, and percent overlap of recruited motor unit populations. In the eight recipients still actively involved in research studies, 44/45 of the spiral contacts were still functional. In four participants regularly studied over the course of 1 month to 10.4 years, the charge thresholds of the majority of individual contacts remained stable over time. The four participants with spiral cuffs on their femoral nerves were all able to generate sufficient moment to keep the knees locked during standing after 2-4.5 years. The dorsiflexion moment produced by all four fibular nerve cuffs in the active participants exceeded the value required to prevent foot drop, but no tibial nerve cuffs were able to meet the plantarflexion moment that occurs during push-off at a normal walking speed. The selectivity of two multi-contact spiral cuffs was examined and both were still highly selective for different motor unit populations for up to 6.3 years after implantation. The spiral nerve cuffs examined remain functional in motor and sensory neuroprostheses for 2-11 years after implantation. They exhibit stable charge thresholds, clinically relevant recruitment properties, and functional muscle selectivity. Non-penetrating spiral nerve cuff electrodes appear to be a suitable option

Longterm effects of cardiac mediastinal nerve cryoablation on neural inducibility of atrial fibrillation in canines.

PubMed

Leiria, Tiago Luiz Luz; Glavinovic, Tamara; Armour, J Andrew; Cardinal, René; de Lima, Gustavo Glotz; Kus, Teresa

2011-04-26

In canines, excessive activation of select mediastinal nerve inputs to the intrinsic cardiac nervous system induces atrial fibrillation (AF). Since ablation of neural elements is proposed as an adjunct to circumferential pulmonary vein ablation for AF, we investigated the short and long-term effects of mediastinal nerve ablation on AF inducibility. Under general anesthesia, in 11 dogs several mediastinal nerve sites were identified on the superior vena cava that, when stimulated electrically during the atrial refractory period, reproducibly initiated AF. Cryoablation of one nerve site was then performed and inducibility retested early (1-2 months post Cryo; n=7) or late (4 months post Cryo; n=4). Four additional dogs that underwent a sham procedure were retested 1 to 2 months post-surgery. Stimulation induced AF at 91% of nerve sites tested in control versus 21% nerve sites early and 54% late post-ablation (both P<0.05). Fewer stimuli were required to induce AF in controls versus the Early Cryo group; this capacity returned to normal values in the Late Cryo group. AF episodes were longer in control versus the Early or Late Cryo groups. Heart rate responses to vagal or stellate ganglion stimulation, as well as to local nicotine infusion into the right coronary artery, were similar in all groups. In conclusion, focal damage to intrinsic cardiac neuronal inputs causes short-term stunning of neuronal inducibility of AF without major loss of overall adrenergic or cholinergic efferent neuronal control. That recovery of AF inducibility occurs rapidly post-surgery indicates the plasticity of intrathoracic neuronal elements to focal injury. Copyright © 2011 Elsevier B.V. All rights reserved.

Determining the functional sensibility of the hand in patients with peripheral nerve repair: Feasibility of using a novel manual tactile test for monitoring the progression of nerve regeneration.

PubMed

Hsu, Hsiu-Yun; Kuo, Li-Chieh; Kuan, Ta-Shen; Yang, Hsiu-Ching; Su, Fong-Chin; Chiu, Haw-Yen; Shieh, Shyh-Jou

Case-controlled cohort study. Sensory function is difficult to observe during nerve regeneration processes. Traditional sensory tests are limited to identifying the level of functioning hand sensation for sensory stimulus is given passively to the cutaneous surface of the hand. To examine the outcome changes in the manual tactile test (MTT), Semmes-Weinstein monofilament (SWM) and 2-point discrimination (2PD) tests for patients with nerve repair and to investigate the concurrent validity of MTT by comparing it with the results of traditional tests. Fifteen patients with nerve injury of the upper limbs were recruited, along with 15 matched healthy controls. The MTT, SWM, and 2PD tests were used to examine the sensory status of the subjects. Three subtests (barognosis, roughness differentiation, and stereognosis) in MTT showed that the patients improved with time. A moderate and mild correlation was found between the MTT and 2PD results and between the barognosis and SWM results. The MTT provides practical and functional perspectives on detecting nerve progression during the courses of degeneration and regeneration. IV. Copyright © 2016 Hanley & Belfus. Published by Elsevier Inc. All rights reserved.

Effects of Local Compression on Peroneal Nerve Function in Humans

NASA Technical Reports Server (NTRS)

Hargens, Alan R.; Botte, Michael J.; Swenson, Michael R.; Gelberman, Richard H.; Rhoades, Charles E.; Akeson, Wayne H.

1993-01-01

A new apparatus was developed to compress the anterior compartment selectively and reproducibly in humans. Thirty-five normal volunteers were studied to determine short-term thresholds of local tissue pressure that produce significant neuromuscular dysfunction. Local tissue fluid pressure adjacent to the deep peroneal nerve was elevated by the compression apparatus and continuously monitored for 2-3 h by the slit catheter technique. Elevation of tissue fluid pressure to within 35-40 mm Hg of diastolic blood pressure (approx. 40 mm Hg of in situ pressure in our subjects) elicited a consistent progression of neuromuscular deterioration including, in order, (a) gradual loss of sensation, as assessed by Semmes-Weinstein monofilaments, (b) subjective complaints, (c) reduced nerve conduction velocity, (d) decreased action potential amplitude of the extensor digitorum brevis muscle, and (e) motor weakness of muscles within the anterior compartment. Generally, higher intracompartment at pressures caused more rapid deterioration of neuromuscular function. In two subjects, when in situ compression levels were 0 and 30 mm Hg, normal neuromuscular function was maintained for 3 h. Threshold pressures for significant dysfunction were not always the same for each functional parameter studied, and the magnitudes of each functional deficit did not always correlate with compression level. This variable tolerance to elevated pressure emphasizes the need to monitor clinical signs and symptoms carefully in the diagnosis of compartment syndromes. The nature of the present studies was short term; longer term compression of myoneural tissues may result in dysfunction at lower pressure thresholds.

The influence of vagal control on sex-related differences in left ventricular mechanics and hemodynamics.

PubMed

Williams, Alexandra Mackenzie; Shave, Robert E; Coulson, James M; White, Harriet; Rosser-Stanford, Bryn; Eves, Neil Derek

2018-06-01

Left ventricular (LV) twist mechanics differ between males and females during acute physiological stress, which may be partly mediated by sex differences in autonomic control. While males appear to have greater adrenergic control of LV twist, the potential contribution of vagal modulation to sex differences in LV twist remains unknown. Therefore, this study examined the role of vagal control on sex differences in LV twist during graded lower body negative pressure (LBNP) and supine cycling. On two separate visits, LV mechanics were assessed using 2-dimensional speckle-tracking echocardiography in 18 males (22{plus minus}2yr) and 17 females (21{plus minus}4yr) during -40 and -60 mmHg LBNP and 25% and 50% of peak supine cycling workload, with and without glycopyrrolate (vagal blockade). LV twist was not different at baseline but was greater in females during -60 mmHg in both control (F:16.0{plus minus}3.4º, M:12.9{plus minus}2.3º, p=0.004) and glycopyrrolate trials (F:17.7{plus minus}5.9{degree sign}, M:13.9{plus minus}3.3{degree sign}, p<0.001) due to greater apical rotation during control (F:11.9{plus minus}3.6º, M:7.8{plus minus}1.5º, p<0.001) and glycopyrrolate (F:11.6{plus minus}4.9{degree sign}, M:7.1{plus minus}3.6{degree sign}, p=0.009). These sex differences in LV twist consistently coincided with a greater LV sphericity index (i.e. ellipsoid geometry) in females compared to males. In contrast, LV twist did not differ between the sexes during exercise, with or without glycopyrrolate. Females have augmented LV twist compared to males during large reductions to preload, even during vagal blockade. As such, differences in vagal control do not appear to contribute to sex differences in the LV twist responses to physiological stress, but may be related to differences in ventricular geometry.

The role of great auricular-facial nerve neurorrhaphy in facial nerve damage.

PubMed

Sun, Yan; Liu, Limei; Han, Yuechen; Xu, Lei; Zhang, Daogong; Wang, Haibo

2015-01-01

Facial nerve is easy to be damaged, and there are many reconstructive methods for facial nerve reconstructive, such as facial nerve end to end anastomosis, the great auricular nerve graft, the sural nerve graft, or hypoglossal-facial nerve anastomosis. However, there is still little study about great auricular-facial nerve neurorrhaphy. The aim of the present study was to identify the role of great auricular-facial nerve neurorrhaphy and the mechanism. Rat models of facial nerve cut (FC), facial nerve end to end anastomosis (FF), facial-great auricular neurorrhaphy (FG), and control (Ctrl) were established. Apex nasi amesiality observation, electrophysiology and immunofluorescence assays were employed to investigate the function and mechanism. In apex nasi amesiality observation, it was found apex nasi amesiality of FG group was partly recovered. Additionally, electrophysiology and immunofluorescence assays revealed that facial-great auricular neurorrhaphy could transfer nerve impulse and express AChR which was better than facial nerve cut and worse than facial nerve end to end anastomosis. The present study indicated that great auricular-facial nerve neurorrhaphy is a substantial solution for facial lesion repair, as it is efficiently preventing facial muscles atrophy by generating neurotransmitter like ACh.

Carvedilol prevents functional deficits in peripheral nerve mitochondria of rats with oxaliplatin-evoked painful peripheral neuropathy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Areti, Aparna; Komirishetty, Prashanth; Kumar, Ash

Oxaliplatin use as chemotherapeutic agent is frequently limited by cumulative neurotoxicity which may compromise quality of life. Reports relate this neurotoxic effect to oxidative stress and mitochondrial dysfunction in peripheral nerves and dorsal root ganglion (DRG). Carvedilol is an antihypertensive drug, has also been appreciated for its antioxidant and mitoprotective properties. Carvedilol co-treatment did not reduce the anti-tumor effects of oxaliplatin in human colon cancer cells (HT-29), but exhibited free radical scavenging activity against oxaliplatin-induced oxidative stress in neuronal cells (Neuro-2a). Hence, the present study was designed to investigate the effect of carvedilol in the experimental model of oxaliplatin-induced peripheralmore » neuropathy (OIPN) in Sprague-Dawley rats. Oxaliplatin reduced the sensory nerve conduction velocity and produced the thermal and mechanical nociception. Carvedilol significantly (P < 0.001) attenuated these functional and sensorimotor deficits. It also counteracted oxidative/nitrosative stress by reducing the levels of nitrotyrosine and improving the mitochondrial superoxide dismutase expression in both sciatic nerve and DRG tissues. It improved the mitochondrial function and prevented the oxaliplatin-induced alteration in mitochondrial membrane potential in sciatic nerve thus prevented loss of intra epidermal nerve fiber density in the foot pads. Together the results prompt the use of carvedilol along with chemotherapy with oxaliplatin to prevent the peripheral neuropathy. - Graphical abstract: Schematic representation neuroprotective mechanisms of carvedilol in oxaliplatin-induced peripheral neuropathy. - Highlights: • Oxaliplatin-induced mitochondrial dysfunction causes neurotoxicity. • Mitochondrial dysfunction leads to bioenergetic and functional deficits. • Carvedilol alleviated oxaliplatin-induced behavioural and functional changes. • Targeting mitochondria with carvedilol attenuated neuropathic

Delineation of vagal emetic pathways: intragastric copper sulfate-induced emesis and viral tract tracing in musk shrews

PubMed Central

Meyers, Kelly; Lim, Audrey; Dye, Matthew; Pak, Diana; Rinaman, Linda; Yates, Bill J.

2014-01-01

Signals from the vestibular system, area postrema, and forebrain elicit nausea and vomiting, but gastrointestinal (GI) vagal afferent input arguably plays the most prominent role in defense against food poisoning. It is difficult to determine the contribution of GI vagal afferent input on emesis because various agents (e.g., chemotherapy) often act on multiple sensory pathways. Intragastric copper sulfate (CuSO4) potentially provides a specific vagal emetic stimulus, but its actions are not well defined in musk shrews (Suncus murinus), a primary small animal model used to study emesis. The aims of the current study were 1) to investigate the effects of subdiaphragmatic vagotomy on CuSO4-induced emesis and 2) to conduct preliminary transneuronal tracing of the GI-brain pathways in musk shrews. Vagotomy failed to inhibit the number of emetic episodes produced by optimal emetic doses of CuSO4 (60 and 120 mg/kg ig), but the effects of lower doses were dependent on an intact vagus (20 and 40 mg/kg). Vagotomy also failed to affect emesis produced by motion (1 Hz, 10 min) or nicotine administration (5 mg/kg sc). Anterograde transport of the H129 strain of herpes simplex virus-1 from the ventral stomach wall identified the following brain regions as receiving inputs from vagal afferents: the nucleus of the solitary tract, area postrema, and lateral parabrachial nucleus. These data indicate that the contribution of vagal pathways to intragastric CuSO4-induced emesis is dose dependent in musk shrews. Furthermore, the current neural tracing data suggest brain stem anatomical circuits that are activated by GI signaling in the musk shrew. PMID:24430885

Surgical Approaches to Facial Nerve Deficits

PubMed Central

Birgfeld, Craig; Neligan, Peter

2011-01-01

The facial nerve is one of the most commonly injured cranial nerves. Once injured, the effects on form, function, and psyche are profound. We review the anatomy of the facial nerve from the brain stem to its terminal branches. We also discuss the physical exam findings of facial nerve injury at various levels. Finally, we describe various reconstructive options for reanimating the face and restoring both form and function. PMID:22451822

Low vagally-mediated heart rate variability and increased susceptibility to ventricular arrhythmias in rats bred for high anxiety.

PubMed

Carnevali, Luca; Trombini, Mimosa; Graiani, Gallia; Madeddu, Denise; Quaini, Federico; Landgraf, Rainer; Neumann, Inga D; Nalivaiko, Eugene; Sgoifo, Andrea

2014-04-10

In humans, there is a documented association between anxiety disorders and cardiovascular disease. Putative underlying mechanisms may include an impairment of the autonomic nervous system control of cardiac function. The primary objective of the present study was to characterize cardiac autonomic modulation and susceptibility to arrhythmias in genetic lines of rats that differ largely in their anxiety level. To reach this goal, electrocardiographic recordings were performed in high-anxiety behavior (HAB, n=10) and low-anxiety behavior (LAB, n=10) rats at rest, during stressful stimuli and under autonomic pharmacological manipulations, and analyzed by means of time- and frequency-domain indexes of heart rate variability. During resting conditions, HAB rats displayed a reduced heart rate variability, mostly in terms of lower parasympathetic (vagal) modulation compared to LAB rats. In HAB rats, this relatively low cardiac vagal control was associated with smaller heart rate responsiveness to acute stressors compared to LAB counterparts. In addition, beta-adrenergic pharmacological stimulation induced a larger incidence of ventricular tachyarrhythmias in HABs compared to LABs. At sacrifice, a moderate increase in heart-body weight ratio was observed in HAB rats. We conclude that high levels of anxiety-related behavior in rats are associated with signs of i) impaired autonomic modulation of heart rate (low vagally-mediated heart rate variability), ii) poor adaptive heart rate responsiveness to stressful stimuli, iii) increased arrhythmia susceptibility, and iv) cardiac hypertrophy. These results highlight the utility of the HAB/LAB model for investigating the mechanistic basis of the comorbidity between anxiety disorders and cardiovascular disease. Copyright © 2014 Elsevier Inc. All rights reserved.

Ablation of the Right Cardiac Vagus Nerve Reduces Acetylcholine Content without Changing the Inflammatory Response during Endotoxemia.

PubMed

Plaschke, Konstanze; Do, Thuc Quyen Monica; Uhle, Florian; Brenner, Thorsten; Weigand, Markus A; Kopitz, Jürgen

2018-02-01

Acetylcholine is the main transmitter of the parasympathetic vagus nerve. According to the cholinergic anti-inflammatory pathway (CAP) concept, acetylcholine has been shown to be important for signal transmission within the immune system and also for a variety of other functions throughout the organism. The spleen is thought to play an important role in regulating the CAP. In contrast, the existence of a "non-neuronal cardiac cholinergic system" that influences cardiac innervation during inflammation has been hypothesized, with recent publications introducing the heart instead of the spleen as a possible interface between the immune and nervous systems. To prove this hypothesis, we investigated whether selectively disrupting vagal stimulation of the right ventricle plays an important role in rat CAP regulation during endotoxemia. We performed a selective resection of the right cardiac branch of the Nervus vagus (VGX) with a corresponding sham resection in vehicle-injected and endotoxemic rats. Rats were injected with lipopolysaccharide (LPS, 1 mg/kg body weight, intravenously) and observed for 4 h. Intraoperative blood gas analysis was performed, and hemodynamic parameters were assessed using a left ventricular pressure-volume catheter. Rat hearts and blood were collected, and the expression and concentration of proinflammatory cytokines using quantitative reverse transcription polymerase chain reaction and enzyme-linked immunosorbent assay were measured, respectively. Four hours after injection, LPS induced a marked deterioration in rat blood gas parameters such as pH value, potassium, base excess, glucose, and lactate. The mean arterial blood pressure and the end-diastolic volume had decreased significantly. Further, significant increases in blood cholinesterases and in proinflammatory (IL-1β, IL-6, TNF-α) cytokine concentration and gene expression were obtained. Right cardiac vagus nerve resection (VGX) led to a marked decrease in heart acetylcholine

Ablation of the Right Cardiac Vagus Nerve Reduces Acetylcholine Content without Changing the Inflammatory Response during Endotoxemia

PubMed Central

Plaschke, Konstanze; Do, Thuc Quyen Monica; Brenner, Thorsten; Weigand, Markus A.; Kopitz, Jürgen

2018-01-01

Acetylcholine is the main transmitter of the parasympathetic vagus nerve. According to the cholinergic anti-inflammatory pathway (CAP) concept, acetylcholine has been shown to be important for signal transmission within the immune system and also for a variety of other functions throughout the organism. The spleen is thought to play an important role in regulating the CAP. In contrast, the existence of a “non-neuronal cardiac cholinergic system” that influences cardiac innervation during inflammation has been hypothesized, with recent publications introducing the heart instead of the spleen as a possible interface between the immune and nervous systems. To prove this hypothesis, we investigated whether selectively disrupting vagal stimulation of the right ventricle plays an important role in rat CAP regulation during endotoxemia. We performed a selective resection of the right cardiac branch of the Nervus vagus (VGX) with a corresponding sham resection in vehicle-injected and endotoxemic rats. Rats were injected with lipopolysaccharide (LPS, 1 mg/kg body weight, intravenously) and observed for 4 h. Intraoperative blood gas analysis was performed, and hemodynamic parameters were assessed using a left ventricular pressure-volume catheter. Rat hearts and blood were collected, and the expression and concentration of proinflammatory cytokines using quantitative reverse transcription polymerase chain reaction and enzyme-linked immunosorbent assay were measured, respectively. Four hours after injection, LPS induced a marked deterioration in rat blood gas parameters such as pH value, potassium, base excess, glucose, and lactate. The mean arterial blood pressure and the end-diastolic volume had decreased significantly. Further, significant increases in blood cholinesterases and in proinflammatory (IL-1β, IL-6, TNF-α) cytokine concentration and gene expression were obtained. Right cardiac vagus nerve resection (VGX) led to a marked decrease in heart acetylcholine

Efficacy of electroacupuncture compared with transcutaneous electric nerve stimulation for functional constipation

PubMed Central

Zeng, Yuxiao; Zhang, Xuecheng; Zhou, Jing; Wang, Xinwei; Jiao, Ruimin; Liu, Zhishun

2018-01-01

Abstract Background: To treat functional constipation, both electroacupuncture (EA) therapy and transcutaneous electric nerve stimulation (TENS) are safe and effective. However, no head-to-head comparison trial has been conducted. This trial compares the efficacy of electroacupuncture relative to transcutaneous electric nerve stimulation for functional constipation. Methods: Individuals with functional constipation will be randomly allocated to receive either EA or TENS (n = 51, each), 3 times per week for 8 weeks. The primary outcome is the percentage of participants with an average increase from baseline of 1 or more complete spontaneous bowel movements at week 8. The secondary outcome measures are the following: at the time of visits, changes in the number of complete spontaneous bowel movements, number of spontaneous bowel movements, stool character, difficulty in defecation, patients’ assessment of quality of life regarding constipation (self-report questionnaire), and use of auxiliary defecation methods. Discussion: The results of this trial should verify whether EA is more efficacious than TENS for relieving symptoms of functional constipation. The major limitation of the study is the lack of blinding of the participants and acupuncturist. PMID:29742718

[Does intraoperative nerve monitoring reduce the rate of recurrent nerve palsies during thyroid surgery?].

PubMed

Timmermann, W; Dralle, H; Hamelmann, W; Thomusch, O; Sekulla, C; Meyer, Th; Timm, S; Thiede, A

2002-05-01

Two different aspects of the influence of neuromonitoring on the possible reduction of post-operative recurrent laryngeal nerve palsies require critical examination: the nerve identification and the monitoring of it's functions. Due to the additional information from the EMG signals, neuromonitoring is the best method for identifying the nerves as compared to visual identification alone. There are still no randomized studies available that compare the visual and electrophysiological recurrent laryngeal nerve detection in thyroid operations with respect to the postoperative nerve palsies. Nevertheless, comparisons with historical collectives show that a constant low nerve-palsy-rate was achieved with electrophysiological detection in comparison to visual detection. The rate of nerve identification is normally very high and amounts to 99 % in our own patients. The data obtained during the "Quality assurance of benign and malignant Goiter" study show that in hemithyreoidectomy and subtotal resection, lower nerve-palsy-rates are achieved with neuromonitoring as compared to solely visual detection. Following subtotal resection, this discrepancy becomes even statistically significant. While monitoring the nerve functions with the presently used neuromonitoring technique, it is possible to observe the EMG-signal remaining constant or decreasing in volume. Assuming that a constant neuromonitoring signal represents a normal vocal cord, our evaluation shows that there is a small percentage of false negative and positive results. Looking at the permanent recurrent nerve palsy rates, this method has a specificity of 98 %, a sensitivity of 100 %, a positive prognostic value of 10 %, and a negative prognostic value of 100 %. Although an altered neuromonitoring signal can be taken as a clear indication of eventual nerve damage, an absolutely reliable statement about the postoperative vocal cord function is presently not possible with intraoperative neuromonitoring.

Genipin-Cross-Linked Chitosan Nerve Conduits Containing TNF-α Inhibitors for Peripheral Nerve Repair.

PubMed

Zhang, Li; Zhao, Weijia; Niu, Changmei; Zhou, Yujie; Shi, Haiyan; Wang, Yalin; Yang, Yumin; Tang, Xin

2018-07-01

Tissue engineered nerve grafts (TENGs) are considered a promising alternative to autologous nerve grafting, which is considered the "gold standard" clinical strategy for peripheral nerve repair. Here, we immobilized tumor necrosis factor-α (TNF-α) inhibitors onto a nerve conduit, which was introduced into a chitosan (CS) matrix scaffold utilizing genipin (GP) as the crosslinking agent, to fabricate CS-GP-TNF-α inhibitor nerve conduits. The in vitro release kinetics of TNF-α inhibitors from the CS-GP-TNF-α inhibitor nerve conduits were investigated using high-performance liquid chromatography. The in vivo continuous release profile of the TNF-α inhibitors released from the CS-GP-TNF-α inhibitor nerve conduits was measured using an enzyme-linked immunosorbent assay over 14 days. We found that the amount of TNF-α inhibitors released decreased with time after the bridging of the sciatic nerve defects in rats. Moreover, 4 and 12 weeks after surgery, histological analyses and functional evaluations were carried out to assess the influence of the TENG on regeneration. Immunochemistry performed 4 weeks after grafting to assess early regeneration outcomes revealed that the TENG strikingly promoted axonal outgrowth. Twelve weeks after grafting, the TENG accelerated myelin sheath formation, as well as functional restoration. In general, the regenerative outcomes following TENG more closely paralleled findings observed with autologous grafting than the use of the CS matrix scaffold. Collectively, our data indicate that the CS-GP-TNF-α inhibitor nerve conduits comprised an elaborate system for sustained release of TNF-α inhibitors in vitro, while studies in vivo demonstrated that the TENG could accelerate regenerating axonal outgrowth and functional restoration. The introduction of CS-GP-TNF-α-inhibitor nerve conduits into a scaffold may contribute to an efficient and adaptive immune microenvironment that can be used to facilitate peripheral nerve repair.

Effect of phrenic nerve palsy on early postoperative lung function after pneumonectomy: a prospective study.

PubMed

Kocher, Gregor J; Mauss, Karl; Carboni, Giovanni L; Hoksch, Beatrix; Kuster, Roland; Ott, Sebastian R; Schmid, Ralph A

2013-12-01

The issue of phrenic nerve preservation during pneumonectomy is still an unanswered question. So far, its direct effect on immediate postoperative pulmonary lung function has never been evaluated in a prospective trial. We conducted a prospective crossover study including 10 patients undergoing pneumonectomy for lung cancer between July 2011 and July 2012. After written informed consent, all consecutive patients who agreed to take part in the study and in whom preservation of the phrenic nerve during operation was possible, were included in the study. Upon completion of lung resection, a catheter was placed in the proximal paraphrenic tissue on the pericardial surface. After an initial phase of recovery of 5 days all patients underwent ultrasonographic assessment of diaphragmatic motion followed by lung function testing with and without induced phrenic nerve palsy. The controlled, temporary paralysis of the ipsilateral hemidiaphragm was achieved by local administration of lidocaine 1% at a rate of 3 mL/h (30 mg/h) via the above-mentioned catheter. Temporary phrenic nerve palsy was accomplished in all but 1 patient with suspected catheter dislocation. Spirometry showed a significant decrease in dynamic lung volumes (forced expiratory volume in 1 second and forced vital capacity; p < 0.05) with the paralyzed hemidiaphragm. Blood oxygen saturation levels did not change significantly. Our results show that phrenic nerve palsy causes a significant impairment of dynamic lung volumes during the early postoperative period after pneumonectomy. Therefore, in these already compromised patients, intraoperative phrenic nerve injury should be avoided whenever possible. Copyright © 2013 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

The role of great auricular-facial nerve neurorrhaphy in facial nerve damage

PubMed Central

Sun, Yan; Liu, Limei; Han, Yuechen; Xu, Lei; Zhang, Daogong; Wang, Haibo

2015-01-01

Background: Facial nerve is easy to be damaged, and there are many reconstructive methods for facial nerve reconstructive, such as facial nerve end to end anastomosis, the great auricular nerve graft, the sural nerve graft, or hypoglossal-facial nerve anastomosis. However, there is still little study about great auricular-facial nerve neurorrhaphy. The aim of the present study was to identify the role of great auricular-facial nerve neurorrhaphy and the mechanism. Methods: Rat models of facial nerve cut (FC), facial nerve end to end anastomosis (FF), facial-great auricular neurorrhaphy (FG), and control (Ctrl) were established. Apex nasi amesiality observation, electrophysiology and immunofluorescence assays were employed to investigate the function and mechanism. Results: In apex nasi amesiality observation, it was found apex nasi amesiality of FG group was partly recovered. Additionally, electrophysiology and immunofluorescence assays revealed that facial-great auricular neurorrhaphy could transfer nerve impulse and express AChR which was better than facial nerve cut and worse than facial nerve end to end anastomosis. Conclusions: The present study indicated that great auricular-facial nerve neurorrhaphy is a substantial solution for facial lesion repair, as it is efficiently preventing facial muscles atrophy by generating neurotransmitter like ACh. PMID:26550216

Motor nerve transplantation.

PubMed

Gray, W P; Keohane, C; Kirwan, W O

1997-10-01

The motor nerve transplantation (MNT) technique is used to transfer an intact nerve into a denervated muscle by harvesting a neurovascular pedicle of muscle containing motor endplates from the motor endplate zone of a donor muscle and implanting it into a denervated muscle. Thirty-six adult New Zealand White rabbits underwent reinnervation of the left long peroneal (LP) muscle (fast twitch) with a motor nerve graft from the soleus muscle (slow twitch). The right LP muscle served as a control. Reinnervation was assessed using microstimulatory single-fiber electromyography (SFEMG), alterations in muscle fiber typing and grouping, and isometric response curves. Neurofilament antibody was used for axon staining. The neurofilament studies provided direct evidence of nerve growth from the motor nerve graft into the adjacent denervated muscle. Median motor endplate jitter was 13 microsec preoperatively, and 26 microsec at 2 months, 29.5 microsec at 4 months, and 14 microsec at 6 months postoperatively (p < 0.001). Isometric tetanic tension studies showed a progressive functional recovery in the reinnervated muscle over 6 months. There was no histological evidence of aberrant reinnervation from any source outside the nerve pedicle. Isometric twitch responses and adenosine triphosphatase studies confirmed the conversion of the reinnervated LP muscle to a slow-type muscle. Acetylcholinesterase studies confirmed the presence of functioning motor endplates beneath the insertion of the motor nerve graft. It is concluded that the MNT technique achieves motor reinnervation by growth of new nerve fibers across the pedicle graft into the recipient muscle.

Hypothesis that vagal reinervation of diaphragm could sensitise it to electrical stimulation.

PubMed

Pavlovic, Dragan; Wendt, Michael

2003-03-01

The hypothesis proposed is that restoration of functional capacity of denervated diaphragm may be achieved by reinervating it with vagus nerve. Following trauma, carcinomatose infiltration, and/or large thoracic surgery and neck surgery, phrenic nerve is frequently injured. Reinervation even in the most favourable conditions would not follow and diaphragm would rest permanently denervated and paralysed. This results in unilateral or bilateral paralysis of diaphragm. In principle, intermittent electrical stimulation of the phrenic nerve or diaphragm could elicit regular diaphragm contractions and maintain satisfactory respiration. While this technique could be used in upper motor neurone injury, in lower motor neurone injury and denervated diaphragm, that imposes too high electrical resistance, direct diaphragm pacing is practically impossible. In these cases, long term artificial ventilation is often necessary. Nevertheless, those patients are at high risk to suffer from atelectasis and respiratory infections. We project a hypothesis that reinervation of denervated diaphragm by vagus nerve could re-establishes its sensitivity to intramuscular electrical stimulation and may allow stimulation of the diaphragm by implanted pace-maker electrodes. An appropriate electrical stimulation might then be possible and diaphragm pacing could replace prolonged artificial ventilation in those patients. Restoration of functional capacity of denervated diaphragm could open a perspective for long term diaphragm pacing in patients with irreversible phrenic nerve injury and diaphragm paralysis.

[Blood-nerve barrier: structure and function].

PubMed

Kanda, Takashi

2011-06-01

The blood-nerve barrier (BNB) is a dynamic interface between the endoneurial microenvironment and surrounding extracellular space or blood contents, and is localized the innermost layer of multilayered ensheathing perineurium and endoneurial microvessels. Since the BNB is a key structure controlling the internal milieu of the peripheral nerve parenchyma, adequate understanding of the BNB is crucial for developing treatment strategies for human peripheral nervous system disorders, including Guillain-Barré syndrome, chronic inflammatory demyelinating polyneuropathy, and diabetic and various metabolic/toxic neuropathies. However, fewer studies have been conducted on the BNB, if we compare against the number of studies on the blood-brain barrier. This is because of the lack of adequate human cell lines originating from the BNB. In our laboratory, human immortal cell lines from the BNB, namely, the endothelial cell line and pericyte cell line, have recently been established and vigorous investigations of their biological and physiological properties are now underway. Pericytes constituting the BNB were found to possess robust ability of controlling BNB integrity via secretion of various cytokines and growth factors including bFGF, VEGF, GDNF, BDNF, and angiopoietin-1. Unknown soluble factors secreted by pericytes also contribute to the upregulation of claudin-5 in endothelial cells in the BNB and thus, strengthen the barrier function of the BNB. In diabetic neuropathy, pericytes were shown to regulate the vascular basement membrane, while AGEs were shown to induce basement membrane hypertrophy and disrupt the BNB by increasing the autocrine secretion of VEGF and TGF-beta from pericytes. In this review article, we discuss the macroscopic and microscopic anatomy of the human BNB as well as the molecular mechanisms of mononuclear cell infiltration across the BNB.

Quantification of hand function by power grip and pinch strength force measurements in ulnar nerve lesion simulated by ulnar nerve block.

PubMed

Wachter, Nikolaus Johannes; Mentzel, Martin; Krischak, Gert D; Gülke, Joachim

2017-06-24

In the assessment of hand and upper limb function, grip strength is of the major importance. The measurement by dynamometers has been established. In this study, the effect of a simulated ulnar nerve lesion on different grip force measurements was evaluated. In 25 healthy volunteers, grip force measurement was done by the JAMAR dynamometer (Fabrication Enterprises Inc, Irvington, NY) for power grip and by a pinch strength dynamometer for tip pinch strength, tripod grip, and key pinch strength. A within-subject research design was used in this prospective study. Each subject served as the control by preinjection measurements of grip and pinch strength. Subsequent measurements after ulnar nerve block were used to examine within-subject change. In power grip, there was a significant reduction of maximum grip force of 26.9% with ulnar nerve block compared with grip force without block (P < .0001). Larger reductions in pinch strength were observed with block: 57.5% in tip pinch strength (P < .0001), 61.0% in tripod grip (P < .0001), and 58.3% in key pinch strength (P < .0001). The effect of the distal ulnar nerve block on grip and pinch force could be confirmed. However, the assessment of other dimensions of hand strength as tip pinch, tripod pinch and key pinch had more relevance in demonstrating hand strength changes resulting from an distal ulnar nerve lesion. The measurement of tip pinch, tripod grip and key pinch can improve the follow-up in hand rehabilitation. II. Copyright © 2017 Hanley & Belfus. Published by Elsevier Inc. All rights reserved.

Determination of functional and morphologic changes in palmar digital nerves after nonfocused extracorporeal shock wave treatment in horses.

PubMed

Bolt, David M; Burba, Daniel J; Hubert, Jeremy D; Strain, George M; Hosgood, Giselle L; Henk, William G; Cho, Doo-Youn

2004-12-01

To determine functional and morphologic changes in palmar digital nerves after nonfocused extracorporeal shock wave (ESW) treatment in horses. 6 horses. The medial and lateral palmar digital nerves of the left forelimb were treated with nonfocused ESWs. The medial palmar digital nerve of the right forelimb served as a nontreated control nerve. At 3, 7, and 35 days after treatment, respectively, 2 horses each were anesthetized and nerves were surgically exposed. Sensory nerve conduction velocities (SNCVs) of treated and control nerves were recorded, after which palmar digital neurectomies were performed. Morphologic changes in nerves were assessed via transmission electron microscopy. Significantly lower SNCV in treated medial and lateral nerves, compared with control nerves, was found 3 and 7 days after treatment. A significantly lower SNCV was detected in treated medial but not lateral nerves 35 days after treatment. Transmission electron microscopy of treated nerves revealed disruption of the myelin sheath with no evidence of damage to Schwann cell bodies or axons, 3, 7, and 35 days after treatment. Nonfocused ESW treatment of the metacarpophalangeal area resulted in lower SNCV in palmar digital nerves. This effect likely contributes to the post-treatment analgesia observed in horses and may result in altered peripheral pain perception. Horses with preexisting lesions may be at greater risk of sustaining catastrophic injuries when exercised after treatment.

Cardiac Vagal Control and Depressive Symptoms: The Moderating Role of Sleep Quality

PubMed Central

Werner, Gabriela G.; Ford, Brett Q.; Mauss, Iris B.; Schabus, Manuel; Blechert, Jens; Wilhelm, Frank H.

2017-01-01

Lower cardiac vagal control (CVC) has been linked to greater depression. However, this link has not been consistently demonstrated, suggesting the presence of key moderators. Sleep plausibly is one such factor. Therefore, we investigated whether sleep quality moderates the link between CVC (quantified by high-frequency heart rate variability, HF-HRV) and depressive symptoms (assessed using established questionnaires) in 29 healthy women. Results revealed a significant interaction between HF-HRV and sleep quality in predicting depressive symptoms: participants with lower HF-HRV reported elevated depressive symptoms only when sleep quality was also low. In contrast, HF-HRV was not associated with depressive symptoms when sleep quality was high, suggesting a protective function of high sleep quality in the context of lower CVC. PMID:27149648

Allotransplanted DRG neurons or Schwann cells affect functional recovery in a rodent model of sciatic nerve injury.

PubMed

Dayawansa, Samantha; Wang, Ernest W; Liu, Weimin; Markman, John D; Gelbard, Harris A; Huang, Jason H

2014-11-01

In this study, the functional recoveries of Sprague-Dawley rats following repair of a complete sciatic nerve transection using allotransplanted dorsal root ganglion (DRG) neurons or Schwann cells were examined using a number of outcome measures. Four groups were compared: (1) repair with a nerve guide conduit seeded with allotransplanted Schwann cells harvested from Wistar rats, (2) repair with a nerve guide conduit seeded with DRG neurons, (3) repair with solely a nerve guide conduit, and (4) sham-surgery animals where the sciatic nerve was left intact. The results corroborated our previous reported histology findings and measures of immunogenicity. The Wistar-DRG-treated group achieved the best recovery, significantly outperforming both the Wistar-Schwann group and the nerve guide conduit group in the Von Frey assay of touch response (P < 0.05). Additionally, Wistar-DRG and Wistar-Schwann seeded repairs showed lower frequency and severity in an autotomy measure of the self-mutilation of the injured leg because of neuralgia. These results suggest that in complete peripheral nerve transections, surgical repair using nerve guide conduits with allotransplanted DRG and Schwann cells may improve recovery, especially DRG neurons, which elicit less of an immune response.

Effect of long-term electroacupuncture stimulation on recovery of sensorimotor function after peripheral nerve anastomosis.

PubMed

Zhang, Mingxing; Zhang, Ye; Bian, Yuhong; Fu, Hui; Xu, Ying; Guo, Yi

2018-06-01

Recently, application of electroacupuncture (EA) to stimulate nerve regeneration has become a mainstream treatment in clinical rehabilitation and related basic research, but the efficacy of long-term stimulation has not been confirmed. To evaluate the influence of long term EA on peripheral nerve injury (PNI) from multiple angles. Twenty-four rats were divided into three groups: control, PNI and PNI+EA. In the latter two groups, PNI was modelled by transection followed by re-anastomosis of thesciatic nerve. In the PNI+EA group only,EA was delivered using a discontinuous wave with frequency 5 Hz, pulse width 2 ms, and intensity approximately 2 mA, until the affected limb was observed to twitch slightly. The treatment was given for 15 min each time, six times a week (continuously for 6 days followed by a 1-day break) for a total of 8 weeks. The effects of EA on anastomotic sciatic nerve regeneration were evaluated using the sciatic function index (SFI), mechanical withdrawal thresholds, thermo-nociceptive thresholds, conduction velocity of the sciatic nerve and bilateral gastrocnemius wet weight. From weeks 2 to 4 after modelling, the SFI recovery rate in the PNI+EA group was faster than that in the PNI group. In week 4, the SFI of the PNI+EA group was significantly higher than that of the PNI group (p<0.05). However, a significant effect of EA was no longer evident from weeks 5 to 8. There was no effect of acupuncture on anti-amyotrophy and conduction velocity of the sciatic nerve at 8 weeks after modelling. EA did not shorten the paw withdrawal threshold time, but appeared to alleviate thermo-nociceptive sensitivity. Long term repeated stimulation of the same site with EA does not appear to be conducive to the functional recovery of an injured sciatic nerve in rats. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly

Vagal modulation of high mobility group box-1 protein mediates electroacupuncture-induced cardioprotection in ischemia-reperfusion injury.

PubMed

Zhang, Juan; Yong, Yue; Li, Xing; Hu, Yu; Wang, Jian; Wang, Yong-qiang; Song, Wei; Chen, Wen-ting; Xie, Jian; Chen, Xue-mei; Lv, Xin; Hou, Li-li; Wang, Ke; Zhou, Jia; Wang, Xiang-rui; Song, Jian-gang

2015-10-26

Excessive release of high mobility group box-1 (HMGB1) protein from ischemic cardiomyocytes activates inflammatory cascades and enhances myocardial injury after reperfusion. Here we report evidence that electroacupuncture of mice at Neiguan acupoints can inhibit the up-regulation of cardiac HMGB1 following myocardial ischemia and attenuate the associated inflammatory responses and myocardial injury during reperfusion. These benefits of electroacupuncture were partially reversed by administering recombinant HMGB1 to the mice, and further potentiated by administering anti-HMGB1 antibody. Electroacupuncture-induced inhibition of HMGB1 release was markedly reduced by unilateral vagotomy or administration of nicotinic receptor antagonist, but not by chemical sympathectomy. The cholinesterase inhibitor neostigmine mimicked the effects of electroacupuncture on HMGB1 release and myocardial ischemia reperfusion injury. Culture experiments with isolated neonatal cardiomyocytes showed that acetylcholine, but not noradrenaline, inhibited hypoxia-induced release of HMGB1 via a α7nAchR-dependent pathway. These results suggest that electroacupuncture acts via the vagal nerve and its nicotinic receptor-mediated signaling to inhibit HMGB1 release from ischemic cardiomyocytes. This helps attenuate pro-inflammatory responses and myocardial injury during reperfusion.

Vagal modulation of high mobility group box-1 protein mediates electroacupuncture-induced cardioprotection in ischemia-reperfusion injury

PubMed Central

Zhang, Juan; Yong, Yue; Li, Xing; Hu, Yu; Wang, Jian; Wang, Yong-qiang; Song, Wei; Chen, Wen-ting; Xie, Jian; Chen, Xue-mei; Lv, Xin; Hou, Li-li; Wang, Ke; Zhou, Jia; Wang, Xiang-rui; Song, Jian-gang

2015-01-01

Excessive release of high mobility group box-1 (HMGB1) protein from ischemic cardiomyocytes activates inflammatory cascades and enhances myocardial injury after reperfusion. Here we report evidence that electroacupuncture of mice at Neiguan acupoints can inhibit the up-regulation of cardiac HMGB1 following myocardial ischemia and attenuate the associated inflammatory responses and myocardial injury during reperfusion. These benefits of electroacupuncture were partially reversed by administering recombinant HMGB1 to the mice, and further potentiated by administering anti-HMGB1 antibody. Electroacupuncture-induced inhibition of HMGB1 release was markedly reduced by unilateral vagotomy or administration of nicotinic receptor antagonist, but not by chemical sympathectomy. The cholinesterase inhibitor neostigmine mimicked the effects of electroacupuncture on HMGB1 release and myocardial ischemia reperfusion injury. Culture experiments with isolated neonatal cardiomyocytes showed that acetylcholine, but not noradrenaline, inhibited hypoxia-induced release of HMGB1 via a α7nAchR-dependent pathway. These results suggest that electroacupuncture acts via the vagal nerve and its nicotinic receptor-mediated signaling to inhibit HMGB1 release from ischemic cardiomyocytes. This helps attenuate pro-inflammatory responses and myocardial injury during reperfusion. PMID:26499847

Pulmonary arterial distension and vagal afferent nerve activity in anaesthetized dogs.

PubMed

Moore, Jonathan P; Hainsworth, Roger; Drinkhill, Mark J