Altered localization of Cav1.2 (L-type) calcium channels in nerve fibers, Schwann cells, odontoblasts, and fibroblasts of tooth pulp after tooth injury

2004 ◽  
Vol 75 (3) ◽  
pp. 371-383 ◽  
Author(s):  
R.E. Westenbroek ◽  
N.L. Anderson ◽  
M.R. Byers
Keyword(s):  
Calcium Channels ◽  
Schwann Cells ◽  
Nerve Fibers ◽  
Tooth Pulp

Role of calcium channels and protein kinase C for release of norepinephrine and neuropeptide Y

1990 ◽  
Vol 259 (5) ◽  
pp. R925-R930
Author(s):  
M. Haass ◽  
C. Forster ◽  
G. Richardt ◽  
R. Kranzhofer ◽  
A. Schomig
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Calcium Channels ◽  
Calcium Channel ◽  
Neuropeptide Y ◽  
Nerve Fibers ◽  
Extracellular Calcium ◽  
Minor Effect ◽  
Kinase C

The role of calcium for the release of norepinephrine (NE, determined by high-pressure liquid chromatography) and neuropeptide Y (NPY, determined by radioimmunoassay) was investigated in guinea pig perfused hearts with intact sympathetic innervation. In the presence of extracellular calcium (1.85 mM), electrical stimulation of the left stellate ganglion (12 Hz, 1 min) induced a closely related release of NE and NPY with the molar ratio of approximately 400-600 (NE) to 1 (NPY). The stimulation-evoked overflow of both transmitters was dependent from the extracellular calcium concentration and was almost completely suppressed by calcium-free perfusion. The corelease of both transmitters was not affected by the L-type calcium channel blocker felodipine (1-10 microM). However, the overflow of NE and NPY was markedly attenuated by the unselective calcium antagonist flunarizine (1-10 microM) and completely prevented by the neuronal (N-type) calcium channel blockers omega-conotoxin (1-100 nM) and cadmium chloride (10-100 microM), indicating a key role for N-type calcium channels in the exocytotic release of transmitters from cardiac sympathetic nerve fibers. Possibly due to unspecific actions, such as interference with sodium channels or uptake1-blocking properties, the phenylalkylamines verapamil (0.01-10 microM) and gallopamil (1-10 microM) reduced NPY overflow with only a minor effect on NE overflow. The stimulation-induced transmitter release was increased up to twofold by activation of protein kinase C (phorbol 12-myristate 13-acetate, 3 nM-3 microM) and completely suppressed by inhibition of protein kinase C (polymyxin B, 100 microM).(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Schwannoma of the arythenoid

2013 ◽  
Vol 11 (2) ◽  
pp. 224-226 ◽  
Author(s):  
Carlos Eduardo Molinari Nardi ◽  
Alexandre Wakil Burzichelli ◽  
Elio Gilberto Pfuetzenreiter ◽  
Rogerio Aparecido Dedivitis
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Schwann Cells ◽  
Rare Case ◽  
Nerve Fibers ◽  
Endoscopic Procedure ◽  
The Central Nervous System

Schwannoma is a benign encapsulated tumor that originates from the Schwann cells lining nerve fibers outside the central nervous system. We report a rare case of schwannoma that arose from the left arythenoid cartilage The patient underwent excision of the mass through microlaryngeal endoscopic procedure. No recurrence was observed during follow-up.

scholarly journals Grayanotoxin, veratrine, and tetrodotoxin-sensitive sodium pathways in the Schwann cell membrane of squid nerve fibers.

1976 ◽  
Vol 67 (3) ◽  
pp. 369-380 ◽  
Author(s):  
J Villegas ◽  
C Sevcik ◽  
F V Barnola ◽  
R Villegas
Keyword(s):  
Membrane Potential ◽  
Cell Membrane ◽  
Schwann Cell ◽  
Nerve Fiber ◽  
Schwann Cells ◽  
Giant Axon ◽  
Nerve Fibers ◽  
Resting Membrane Potential ◽  
External Application ◽  
Axon Membrane

The actions of grayanotoxin I, veratrine, and tetrodotoxin on the membrane potential of the Schwann cell were studied in the giant nerve fiber of the squid Sepioteuthis sepioidea. Schwann cells of intact nerve fibers and Schwann cells attached to axons cut lengthwise over several millimeters were utilized. The axon membrane potential in the intact nerve fibers was also monitored. The effects of grayanotoxin I and veratrine on the membrane potential of the Schwann cell were found to be similar to those they produce on the resting membrane potential of the giant axon. Thus, grayanotoxin I (1-30 muM) and veratrine (5-50 mug-jl-1), externally applied to the intact nerve fiber or to axon-free nerve fiber sheaths, produce a Schwann cell depolarization which can be reversed by decreasing the external sodium concentration or by external application of tetrodotoxin. The magnitude of these membrane potential changes is related to the concentrations of the drugs in the external medium. These results indicate the existence of sodium pathways in the electrically unexcitable Schwann cell membrane of S. sepioidea, which can be opened up by grayanotoxin I and veratrine, and afterwards are blocked by tetrodotoxin. The sodium pathways of the Schwann cell membrane appear to be different from those of the axolemma which show a voltage-dependent conductance.

Local Anesthetics Selectively Damage Schwann Cells of Unmyelinated Nerve Fibers

1987 ◽  
Vol 67 (3) ◽  
pp. A276-A276
Author(s):  
Robert R. Myers ◽  
Michael W. Kalichman ◽  
Henry C. Powell
Keyword(s):  
Schwann Cells ◽  
Local Anesthetics ◽  
Nerve Fibers ◽  
Unmyelinated Nerve

scholarly journals Schwann cells support oncogenic potential of pancreatic cancer cells through TGFβ signaling

2019 ◽  
Vol 10 (12) ◽  
Author(s):  
Elodie Roger ◽  
Sylvie Martel ◽  
Adrien Bertrand-Chapel ◽  
Arnaud Depollier ◽  
Nicolas Chuvin ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Cancer Cells ◽  
Schwann Cells ◽  
Stromal Cells ◽  
Transforming Growth Factor ◽  
Nerve Fibers ◽  
Dependent Manner ◽  
Tgfβ Signaling ◽  
Pancreatic Cancer Cells ◽  
Neural Remodeling

AbstractPancreatic ductal adenocarcinoma (PDAC) is one of the solid tumors with the poorest prognosis. The stroma of this tumor is abundant and composed of extracellular matrix and stromal cells (including cancer-associated fibroblasts and immune cells). Nerve fibers invading this stroma represent a hallmark of PDAC, involved in neural remodeling, which participates in neuropathic pain, cancer cell dissemination and tumor relapse after surgery. Pancreatic cancer-associated neural remodeling is regulated through functional interplays mediated by physical and molecular interactions between cancer cells, nerve cells and surrounding Schwann cells, and other stromal cells. In the present study, we show that Schwann cells (glial cells supporting peripheral neurons) can enhance aggressiveness (migration, invasion, tumorigenicity) of pancreatic cancer cells in a transforming growth factor beta (TGFβ)-dependent manner. Indeed, we reveal that conditioned medium from Schwann cells contains high amounts of TGFβ able to activate the TGFβ-SMAD signaling pathway in cancer cells. We also observed in human PDAC samples that high levels of TGFβ signaling activation were positively correlated with perineural invasion. Secretome analyses by mass spectrometry of Schwann cells and pancreatic cancer cells cultured alone or in combination highlighted the central role of TGFβ in neuro-epithelial interactions, as illustrated by proteomic signatures related to cell adhesion and motility. Altogether, these results demonstrate that Schwann cells are a meaningful source of TGFβ in PDAC, which plays a crucial role in the acquisition of aggressive properties by pancreatic cancer cells.

Target finding of pain nerve fibers: Neural growth mechanisms in the tooth pulp

2007 ◽  
Vol 92 (1-2) ◽  
pp. 40-45 ◽  
Author(s):  
Kaj Fried ◽  
Christina Lillesaar ◽  
Wondossen Sime ◽  
Nina Kaukua ◽  
Manuel Patarroyo
Keyword(s):  
Nerve Fibers ◽  
Tooth Pulp ◽  
Growth Mechanisms ◽  
Neural Growth

scholarly journals ULTRASTRUCTURE OF THE CAROTID BODY

1966 ◽  
Vol 30 (3) ◽  
pp. 563-578 ◽  
Author(s):  
T. J. Biscoe ◽  
W. E. Stehbens
Keyword(s):  
Blood Vessels ◽  
Schwann Cells ◽  
Carotid Body ◽  
Nerve Fibers ◽  
Nerve Endings ◽  
Type I ◽  
Type Ii Cells ◽  
Type Ii ◽  
Type I Cells ◽  
I Cells

An electron microscope investigation was made of the carotid body in the cat and the rabbit. In thin-walled blood vessels the endothelium was fenestrated. Larger vessels were surrounded by a layer of smooth muscle fibers. Among the numerous blood vessels lay groups of cells of two types covered by basement membranes. Aggregates of Type I cells were invested by Type II cells, though occasionally cytoplasmic extensions were covered by basement membrane only. Type I cells contained many electron-opaque cored vesicles (350 to 1900 A in diameter) resembling those in endocrine secretory cells. Type II cells covered nerve endings terminating on Type I cells and enclosed nerve fibers in much the same manner as Schwann cells. The nerve endings contained numerous microvesicles (∼500 A in diameter), mitochondria, glycogen granules, and a few electron-opaque cored vesicles. Junctions between nerve endings and Type I cells were associated with regions of increased density in both intercellular spaces and the adjoining cytoplasm. Cilia of the 9 + 0 fibril pattern were observed in Type I and Type II cells and pericytes. Nonmyelinated nerve fibers, often containing microvesicles, mitochondria, and a few electron-opaque cored vesicles (650 to 1000 A in diameter) were present in Schwann cells, many of which were situated close to blood vessels Ganglion cells near the periphery of the gland, fibrocytes, and segments of unidentified cells were also seen. It was concluded that, according to present concepts of the structure of nerve endings, those endings related to Type I cells could be efferent or afferent.

scholarly journals Nogo-C Inhibits Peripheral Nerve Regeneration by Regulating Schwann Cell Apoptosis and Dedifferentiation

2021 ◽  
Vol 14 ◽  
Author(s):  
Bo Jia ◽  
Wei Huang ◽  
Yu Wang ◽  
Peng Zhang ◽  
Zhiwei Wang ◽  
...  
Keyword(s):  
Sciatic Nerve ◽  
Schwann Cell ◽  
Peripheral Nerve ◽  
Nerve Regeneration ◽  
Schwann Cells ◽  
Nerve Injury ◽  
Cell Apoptosis ◽  
Peripheral Nerve Regeneration ◽  
Nerve Fibers ◽  
Cell Dedifferentiation

While Nogo protein demonstrably inhibits nerve regeneration in the central nervous system (CNS), its effect on Schwann cells in peripheral nerve repair and regeneration following sciatic nerve injury remains unknown. In this research, We assessed the post-injury expression of Nogo-C in an experimental mouse model of sciatic nerve-crush injury. Nogo-C knockout (Nogo-C–/–) mouse was generated to observe the effect of Nogo-C on sciatic nerve regeneration, Schwann cell apoptosis, and myelin disintegration after nerve injury, and the effects of Nogo-C on apoptosis and dedifferentiation of Schwann cells were observed in vitro. We found that the expression of Nogo-C protein at the distal end of the injured sciatic nerve increased in wild type (WT) mice. Compared with the injured WT mice, the proportion of neuronal apoptosis was significantly diminished and the myelin clearance rate was significantly elevated in injured Nogo-C–/– mice; the number of nerve fibers regenerated and the degree of myelination were significantly elevated in Nogo-C–/– mice on Day 14 after injury. In addition, the recovery of motor function was significantly accelerated in the injured Nogo-C–/– mice. The overexpression of Nogo-C in primary Schwann cells using adenovirus-mediated gene transfer promoted Schwann cells apoptosis. Nogo-C significantly reduced the ratio of c-Jun/krox-20 expression, indicating its inhibition of Schwann cell dedifferentiation. Above all, we hold the view that the expression of Nogo-C increases following peripheral nerve injury to promote Schwann cell apoptosis and inhibit Schwann cell dedifferentiation, thereby inhibiting peripheral nerve regeneration.

scholarly journals Isolated schwannoma of maxillary sinus: a rare occurrence

2020 ◽  
Vol 6 (12) ◽  
pp. 2296
Author(s):  
Glynis Florence Francis ◽  
Vikram Raj Mohanam T. C. ◽  
Lakshanadeve V. M. ◽  
Mary Kurien ◽  
Anand Mohanraj
Keyword(s):  
Peripheral Nerve ◽  
Maxillary Sinus ◽  
Schwann Cells ◽  
Paranasal Sinuses ◽  
Nerve Fibers ◽  
Benign Tumors ◽  
Rare Occurrence ◽  
Nerve Sheath ◽  
The Right ◽  
Visual Disturbances

<p>Schwannomas are benign tumors originating from the neural crests (schwann cells), which are cells that form the nerve sheath of peripheral nerve fibers. Around 25-45% cases of schwannomas occur in the head and neck, of which less than 4% occurs in the nasal cavity and the paranasal sinuses. Isolated schwannomas of the maxillary sinus appear to be extremely rare. We report a case of an isolated maxillary schwannoma in a 45 years old lady who presented with swelling in the right cheek for 1 year and right sided nasal obstruction for 4 months. The swelling was not associated with epistaxis, fever, headache or visual disturbances. We report this case keeping in mind the rarity in occurrence of isolated maxillary schwannomas</p>

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