scholarly journals Brainstem neuropathology in two cases of COVID-19: SARS-CoV-2 trafficking between brain and lung

2021 ◽  
Author(s):  
Gaetano Bulfamante ◽  
Tommaso Bocci ◽  
Monica Falleni ◽  
Laura Campiglio ◽  
Silvia Coppola ◽  
...  
Keyword(s):  
Vagus Nerve ◽  
Neuronal Damage ◽  
Histopathological Examination ◽  
Cranial Nerves ◽  
Nerve Fibers ◽  
Corpora Amylacea ◽  
Immunohistochemical Expression ◽  
Brainstem Reflex ◽  
Respiratory Centers ◽  
Brainstem Anatomy

Abstract Introduction SARS-CoV-2 might spread through the nervous system, reaching respiratory centers in the brainstem. Because we recently reported neurophysiological brainstem reflex abnormalities in COVID-19 patients, we here neuropathologically assessed structural brainstem damage in two COVID-19 patients. Materials and methods We assessed neuropathological features in two patients who died of COVID-19 and in two COVID-19 negative patients as controls. Neuronal damage and corpora amylacea (CA) numbers /mm2 were histopathologically assessed. Other features studied were the immunohistochemical expression of the SARS-CoV-2 nucleoprotein (NP) and the Iba-1 antigen for glial activation. Results Autopsies showed normal gross brainstem anatomy. Histopathological examination demonstrated increased neuronal and CA damage in Covid-19 patients’ medulla oblongata. Immunohistochemistry disclosed SARS-CoV-2 NP in brainstem neurons and glial cells, and in cranial nerves. Glial elements also exhibited a widespread increase in Iba-1 expression. Sars-Co-V2 was immunohistochemically detected in the vagus nerve fibers. Discussion Neuropathologic evidence showing SARS-CoV-2 in the brainstem and medullary damage in the area of respiratory centers strongly suggests that the pathophysiology of COVID-19-related respiratory failure includes a neurogenic component. Sars-Co-V2 detection in the vagus nerve, argues for viral trafficking between brainstem and lung.

scholarly journals Selective stimulation of the ferret abdominal vagus nerve with multi-contact nerve cuff electrodes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jonathan A. Shulgach ◽  
Dylan W. Beam ◽  
Ameya C. Nanivadekar ◽  
Derek M. Miller ◽  
Stephanie Fulton ◽  
...  
Keyword(s):  
Vagus Nerve ◽  
Nerve Fibers ◽  
The Body ◽  
Evoked Responses ◽  
Gi Tract ◽  
Selective Stimulation ◽  
Nerve Cuff ◽  
Cuff Electrodes ◽  
Nerve Cuff Electrodes ◽  
Stimulation Of

AbstractDysfunction and diseases of the gastrointestinal (GI) tract are a major driver of medical care. The vagus nerve innervates and controls multiple organs of the GI tract and vagus nerve stimulation (VNS) could provide a means for affecting GI function and treating disease. However, the vagus nerve also innervates many other organs throughout the body, and off-target effects of VNS could cause major side effects such as changes in blood pressure. In this study, we aimed to achieve selective stimulation of populations of vagal afferents using a multi-contact cuff electrode wrapped around the abdominal trunks of the vagus nerve. Four-contact nerve cuff electrodes were implanted around the dorsal (N = 3) or ventral (N = 3) abdominal vagus nerve in six ferrets, and the response to stimulation was measured via a 32-channel microelectrode array (MEA) inserted into the left or right nodose ganglion. Selectivity was characterized by the ability to evoke responses in MEA channels through one bipolar pair of cuff contacts but not through the other bipolar pair. We demonstrated that it was possible to selectively activate subpopulations of vagal neurons using abdominal VNS. Additionally, we quantified the conduction velocity of evoked responses to determine what types of nerve fibers (i.e., Aδ vs. C) responded to stimulation. We also quantified the spatial organization of evoked responses in the nodose MEA to determine if there is somatotopic organization of the neurons in that ganglion. Finally, we demonstrated in a separate set of three ferrets that stimulation of the abdominal vagus via a four-contact cuff could selectively alter gastric myoelectric activity, suggesting that abdominal VNS can potentially be used to control GI function.

Endings of the vagus nerve fibers in the mammalian heart

1927 ◽  
Vol 23 (6-7) ◽  
pp. 622-623
Author(s):  
B. I. Lavrent'ev
Keyword(s):  
Methylene Blue ◽  
Vagus Nerve ◽  
Nerve Fibers ◽  
Nerve Cells ◽  
Vagus Nerves ◽  
Mammalian Heart ◽  
Cardiac Ganglia ◽  
Important Study ◽  
Spiral Fibers

In 1893, Prof. V.V. Nikolaev, having cut vagus nerves of a frog, saw under a microscope degeneration of so-called spiral fibers and pericellular apparatuses on nerve cells of intracardiac nodes. Later these observations were thoroughly verified by Prof. D.V. Polumordvinov and fully confirmed by him. I had a chance to look through amazing by technique preparations of the late Prof. Polumordvinov, obtained by methylene blue method, on which decay of pericellular apparatuses in cardiac ganglia of a frog was absolutely clearly visible. D. V-ch, who died untimely in 1919, unfortunately, did not have time to publish in detail his important study; the manuscript and drawings of his work also remained undiscovered.

Barbiturates depress vagal motor pathway to ferret trachea at ganglia

1982 ◽  
Vol 53 (1) ◽  
pp. 253-257 ◽  
Author(s):  
B. E. Skoogh ◽  
M. J. Holtzman ◽  
J. R. Sheller ◽  
J. A. Nadel
Keyword(s):  
Neuromuscular Junction ◽  
Vagus Nerve ◽  
Muscle Tension ◽  
Postsynaptic Membrane ◽  
Nerve Fibers ◽  
Motor Pathway ◽  
Parasympathetic Ganglia ◽  
Before And After ◽  
Nerve Muscle

To determine which site in the vagal motor pathway to airway smooth muscle is most sensitive to depression by barbiturates, we recorded isometric muscle tension in vitro and stimulated the vagal motor pathway at four different sites before and after exposure to barbiturates. In isolated tracheal rings from ferrets, we stimulated muscarinic receptors in the neuromuscular junction by exogenous acetylcholine, postganglionic nerve fibers by electrical fluid stimulation, and the postsynaptic membrane in ganglia by 1,1-dimethyl-4-phenylpiperazinium iodide (DMPP). We also developed a tracheal nerve-muscle preparation to stimulate preganglionic fibers in the vagus nerve electrically. Activation of ganglia by DMPP or by vagus nerve stimulation was depressed by barbiturates at 10-fold lower concentrations than those depressing the activation of postganglionic nerves or the neuromuscular junction. These findings suggest that the postsynaptic membrane in parasympathetic ganglia is the site in the vagal motor pathway most sensitive to depression by barbiturates.

SMI-32 — a novel axonal injury marker for investigation of ischemic brain pathology

2021 ◽  
Vol 20 (4) ◽  
pp. 63-68
Author(s):  
Daria L. Tsyba ◽  
Olga V. Kirik ◽  
Dmitrii E. Korzhevskii
Keyword(s):  
Cerebral Ischemia ◽  
Heavy Chain ◽  
Neuronal Damage ◽  
Focal Cerebral Ischemia ◽  
Axonal Injury ◽  
Experimental Models ◽  
Nerve Fibers ◽  
Left Middle Cerebral Artery ◽  
Social Significance ◽  
Neurofilament Proteins

The relevance of this work is determined by the high prevalence and social significance of cerebrovascular diseases and the need to develop effective methods for verifying neuronal damage due to cerebral ischemia in experimental models. The aim of this study was to assess the possibility of immunohistochemical revealing of neurofilaments to detect axonal injury in cerebral ischemia models. Materials and methods. A model of transient focal cerebral ischemia by the left middle cerebral artery occlusion was reproduced in male Wistar, SHR and WKY rats. Axonal injury was assessed by immunohistochemical reactions for neurofilament proteins using SMI-32 and 2F11 antibodies. Results. In cerebral ischemia, damage to nerve fibers occurs, manifested by thickening of axons, their varicose expansion and segmental accumulation of neurofilament proteins. These changes are more noticeable with an immunohistochemical reaction to the SMI-32 marker of neurofilament heavy chain. Conclusions. The use of antibodies to the non-phosphorylated neurofilament heavy chain makes it easy to identify degenerating nerve fibers and can be recommended as an alternative method for detecting axonal injury.

scholarly journals Intracranial nonvestibular neurinomas: Young neurosurgeons’ experience

2014 ◽  
Vol 05 (03) ◽  
pp. 231-243
Author(s):  
Forhad Hossain Chowdhury ◽  
Mohammod R. Haque ◽  
Khandkar A. Kawsar ◽  
Mainul H. Sarker ◽  
Mahmudul Hasan ◽  
...  
Keyword(s):  
Vagus Nerve ◽  
Cranial Nerve ◽  
Cranial Nerves ◽  
Craniovertebral Junction ◽  
Jugular Foramen ◽  
Clinical Profile ◽  
Clinical Feature ◽  
Subtotal Resection ◽  
Total Resection

ABSTRACT Background and Objectives: Neurinoma arising from other than nonvestibular cranial nerves is less prevalent. Here we present our experiences regarding the clinical profile, investigations, microneurosurgical management, and the outcome of nonvestibular cranial nerve neurinomas. Materials and Methods: From January 2005 to December 2011, the recorded documents of operated nonvestibular intracranial neurinomas were retrospectively studied for clinical profile, investigations, microneurosurgical management, complications, follow-up, and outcomes. Results: The average follow-up was 24.5 months. Total number of cases was 30, with age ranging from 9 to 60 years. Sixteen cases were males and 14 were females. Nonvestibular cranial nerve schwannomas most commonly originated from trigeminal nerve followed by glossopharyngeal+/vagus nerve. There were three abducent nerve schwannomas that are very rare. There was no trochlear nerve schwannoma. Two glossopharyngeal+/vagus nerve schwannomas extended into the neck through jugular foramen and one extended into the upper cervical spinal canal. Involved nerve dysfunction was a common clinical feature except in trigeminal neurinomas where facial pain was a common feature. Aiming for no new neurodeficit, total resection of the tumor was done in 24 cases, and near-total resection or gross total resection or subtotal resection was done in 6 cases. Preoperative symptoms improved or disappeared in 25 cases. New persistent deficit occurred in 3 cases. Two patients died postoperatively. There was no recurrence of tumor till the last follow-up. Conclusion: Nonvestibular schwannomas are far less common, but curable benign lesions. Surgical approach to the skull base and craniovertebral junction is a often complex and lengthy procedure associated with chances of significant morbidity. But early diagnosis, proper investigations, and evaluation, along with appropriate decision making and surgical planning with microsurgical techniques are the essential factors that can result in optimum outcome.

scholarly journals Comparison of the efficiency of chopped and non-rectangular electrical stimulus waveforms in activating small vagus nerve fibers

2019 ◽  
Vol 320 ◽  
pp. 1-8 ◽  
Author(s):  
Mélissa Dali ◽  
Chloé Picq ◽  
Olivier Rossel ◽  
Pawel Maciejasz ◽  
Charles-Henri Malbert ◽  
...  
Keyword(s):  
Vagus Nerve ◽  
Electrical Stimulus ◽  
Nerve Fibers

Pathophysiology of Tinnitus

1984 ◽  
Vol 93 (1) ◽  
pp. 39-44 ◽  
Author(s):  
Aage R. Møsller
Keyword(s):  
Auditory Nerve ◽  
Neural Coding ◽  
Temporal Pattern ◽  
Phase Locking ◽  
Cranial Nerves ◽  
Nerve Fibers ◽  
Complex Sounds ◽  
Ephaptic Transmission ◽  
Recent Developments ◽  
Auditory Nerve Fibers

The hypothesis is presented that certain forms of tinnitus are related to abnormal phase-locking of discharges in groups of auditory nerve fibers. Recent developments in auditory neurophysiology have shown that neural coding of the temporal pattern of sounds plays an important role in the analysis of complex sounds. In addition, it has been demonstrated that when some other cranial nerves are damaged, artificial synapses can occur between individual nerve fibers such that ephaptic transmission between nerve fibers is facilitated. Such “crosstalk” between auditory nerve fibers is assumed to result in phase-locking of the spontaneous activity of groups of neurons which in the absence of external sounds creates a neural pattern that resembles that evoked by sounds.

Microsurgical Treatment of Glossopharyngeal Neuralgia: Case Reports

Neurosurgery ◽  
1989 ◽  
Vol 25 (4) ◽  
pp. 630-632 ◽  
Author(s):  
Bernardo Fraioli ◽  
Vincenzo Esposito ◽  
Luigi Ferrante ◽  
Lanfranco Trubiani ◽  
Pierpaolo Lunardi
Keyword(s):  
Vagus Nerve ◽  
Cranial Nerve ◽  
Open Surgery ◽  
Case Reports ◽  
Cranial Nerves ◽  
Posterior Cranial Fossa ◽  
Glossopharyngeal Neuralgia ◽  
Neurovascular Compression ◽  
Cerebellar Artery ◽  
Cranial Fossa

Abstract Three patients with excruciating glossopharyngeal neuralgia underwent microsurgical operations in the posterior cranial fossa. In each patient, neurovascular compression was found involving the posteroinferior cerebellar artery and involving the 9th and 10th cranial nerves. In two of the patients, the compression was caused by arachnoiditis and in the other by an arterial loop. In each patient, neuralgia was successfully eliminated by microvascular decompression and by section of the upper rootlets of the vagus nerve. In one patient, partial section of the 9th cranial nerve was also performed. Because of the frequent involvement of the vagus nerve in the pathogenesis of this condition, open surgery should be preferable to percutaneous thermorhizotomy, which is unable to act selectively on the 10th cranial nerve.

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