scholarly journals Neuropeptides and the Nodes of Ranvier in Cranial Headaches

2022 ◽  
Vol 12 ◽  
Author(s):  
Jacob C. A. Edvinsson ◽  
Kristian A. Haanes ◽  
Lars Edvinsson
Keyword(s):  
Trigeminovascular System ◽  
Satellite Glial Cells ◽  
Entry Zone ◽  
Root Entry Zone ◽  
C Fibers ◽  
Calcitonin Gene ◽  
The Central Nervous System ◽  
Sensory Fibers ◽  
Different Parts

The trigeminovascular system (TGV) comprise of the trigeminal ganglion with neurons and satellite glial cells, with sensory unmyelinated C-fibers and myelinated Aδ-fibers picking up information from different parts of the head and sending signals to the brainstem and the central nervous system. In this review we discuss aspects of signaling at the distal parts of the sensory fibers, the extrasynaptic signaling between C-fibers and Aδ-fibers, and the contact between the trigeminal fibers at the nerve root entry zone where they transit into the CNS. We also address the possible role of the neuropeptides calcitonin gene-related peptide (CGRP), the neurokinin family and pituitary adenylyl cyclase-activating polypeptide 38 (PACAP-38), all found in the TGV system together with their respective receptors. Elucidation of the expression and localization of neuropeptides and their receptors in the TGV system may provide novel ways to understand their roles in migraine pathophysiology and suggest novel ways for treatment of migraine patients.

scholarly journals Role Of Cgrp In Sensitization Of Dura Mater

2001 ◽  
Vol 1 ◽  
pp. 20-20
Author(s):  
K. Messlinger
Keyword(s):  
Dura Mater ◽  
Trigeminal Nerve ◽  
Plasma Levels ◽  
Nerve Fibers ◽  
Considerable Proportion ◽  
Trigeminovascular System ◽  
Dura Mater Encephali ◽  
Related Peptide ◽  
Calcitonin Gene

The mammalian dura mater encephali is richly supplied by trigeminal nerve fibers, a considerable proportion of which contains calcitonin gene-related peptide (CGRP). As plasma levels of CGRP are increased in some forms of headaches, the question is in which way CGRP is involved in nociceptive mechanisms within the peripheral and the central trigeminovascular system.

The spinal projection of individual identified A-delta- and C-fibers

1988 ◽  
Vol 59 (1) ◽  
pp. 41-55 ◽  
Author(s):  
R. J. Traub ◽  
L. M. Mendell
Keyword(s):  
Conduction Velocity ◽  
Dorsal Root ◽  
High Threshold ◽  
Entry Zone ◽  
Root Entry Zone ◽  
C Fibers ◽  
Spinal Projection ◽  
Dorsal Columns ◽  
Adequate Stimulus ◽  
Low Threshold

1. Recordings were made from individual sensory neurons with an A-delta peripheral conduction velocity, either intrasomally in the L7 dorsal root ganglion, or extracellularly in Lissauer's Tract or in the dorsal root close to the root entry zone. The spinal projection of these afferents was assessed by their antidromic response to stimulation of the dorsal columns (DC) or Lissauer's Tract (LT) at the L5/L6 border. The adequate stimulus was also ascertained. 2. A-delta-fibers could be divided into two groups: high-threshold mechanoreceptors from either skin or muscle (HTMRs) and low-threshold mechanoreceptors (LTMs), primarily Down Hairs. A third group of cells recorded intrasomally had broad spikes with shoulders on the downstroke characteristic of A-delta-nociceptors and were so classified provisionally, although no adequate stimulus could be identified. HTMRs and broad spike cells projected either in DC or LT, but LTMs projected only in DC, never in LT. About one-quarter of both groups failed to project rostrally as far as L5/L6. 3. Cells with unmyelinated axons recorded intrasomally were found to supply either low-threshold or high-threshold mechanoreceptors. Unlike A-delta-cells, all these cells had broad spikes with shoulders on the downstroke. Proportionally fewer C-fibers than A-delta-fibers projected as far as one segment rostral from their root entry zone. Of those that did, axons supplying low-threshold mechanoreceptors projected only in DC, whereas those innervating high-threshold mechanoreceptors could project either through LT or DC. 4. A-delta-fibers supplying LTMs and HTMRs exhibited a similar reduced conduction velocity was reduced even further in the spinal cord but much more for HTMRs than for LTMs. For C-fibers the conduction velocity decrease was more substantial in the dorsal root for HTMRs than for LTMs. 5. These findings suggest that axons innervating different peripheral receptors exhibit characteristic cellular properties. They confirm that the primary afferent component of Lissauer's Tract is specialized as a “pain pathway” but also indicate that the dorsal columns may play some role in the transmission of nociceptive information.

The Role of Endocannabinoid Signaling in Motor Control

Physiology ◽  
2010 ◽  
Vol 25 (4) ◽  
pp. 230-238 ◽  
Author(s):  
A. El Manira ◽  
A. Kyriakatos
Keyword(s):  
Central Nervous System ◽  
Motor Skills ◽  
Motor System ◽  
Cannabinoid Receptors ◽  
Retrograde Signaling ◽  
Motor Circuits ◽  
The Central Nervous System ◽  
Different Parts

Cannabinoid receptors and endocannabinoid signaling are distributed throughout the rostrocaudal neuraxis. Retrograde signaling via endocannabinoid mediates synaptic plasticity in many regions in the central nervous system. Here, we review the role of endocannabinoid signaling in different parts of the vertebrate motor system from networks responsible for the execution of movement to planning centers in the basal ganglia and cortex. The ubiquity of endocannabinoid-mediated plasticity suggests that it plays an important role in producing motion from defined circuitries and also for reconfiguring networks to learn new motor skills. The long-term plasticity induced by endocannabinoids may provide a long-term buffer that stabilizes the organization of motor circuits and their activity.

Neuropharmacology of the Dorsal Root Entry Zone

Neurosurgery ◽  
1984 ◽  
Vol 15 (6) ◽  
pp. 900-903 ◽  
Author(s):  
Major Bennett Blumenkopf
Keyword(s):  
Dorsal Root ◽  
Root Avulsion ◽  
Endogenous Opiates ◽  
Entry Zone ◽  
Dorsal Root Entry Zone ◽  
Avulsion Injury ◽  
Root Entry Zone ◽  
Neural Transmission ◽  
The Central Nervous System ◽  
Nerve Root Avulsion

Abstract The finding of a number of peptides in the central nervous system and the discovery of the endogenous opiates represent major recent advances in the understanding of neural transmission. A number of these neuropeptides are found in the dorsal root entry zone and may play a role in pain. An analysis of changes in distribution of substance P, methionineenkephalin, and somatostatin after simulated nerve root avulsion injury suggested a possible mechanism for deafferentation pain. A review of the localizations and actions of these peptides in the dorsal root entry zone is included.

Integrating Pathophysiology in Migraine: Role of the Gut Microbiome and Melatonin

2019 ◽  
Vol 25 (33) ◽  
pp. 3550-3562 ◽  
Author(s):  
George Anderson
Keyword(s):  
Metabolic Regulation ◽  
Relative Increase ◽  
Future Research ◽  
Satellite Glial Cells ◽  
Clinical Utilization ◽  
Excitatory Transmission ◽  
Calcitonin Gene ◽  
Current Article ◽  
Butyrate Production

Background: The pathoetiology and pathophysiology of migraine are widely accepted as unknown. Methods: The current article reviews the wide array of data associated with the biological underpinnings of migraine and provides a framework that integrates previously disparate bodies of data. Results: The importance of alterations in stress- and pro-inflammatory cytokine- induced gut dysbiosis, especially butyrate production, are highlighted. This is linked to a decrease in the availability of melatonin, and a relative increase in the N-acetylserotonin/melatonin ratio, which has consequences for the heightened glutamatergic excitatory transmission in migraine. It is proposed that suboptimal mitochondria functioning and metabolic regulation drive alterations in astrocytes and satellite glial cells that underpin the vasoregulatory and nociceptive changes in migraine. Conclusion: This provides a framework not only for classical migraine associated factors, such as calcitonin-gene related peptide and serotonin, but also for wider factors in the developmental pathoetiology of migraine. A number of future research and treatment implications arise, including the clinical utilization of sodium butyrate and melatonin in the management of migraine.

Role of Postoperative Magnetic Resonance Imaging after Microvascular Decompression of the Facial Nerve for the Treatment of Hemifacial Spasm

Neurosurgery ◽  
2002 ◽  
Vol 50 (4) ◽  
pp. 720-726 ◽  
Author(s):  
Jin Woo Chang ◽  
Jong Hee Chang ◽  
Jae Young Choi ◽  
Dong Ik Kim ◽  
Yong Gou Park ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Magnetic Resonance Angiography ◽  
Facial Nerve ◽  
Hemifacial Spasm ◽  
Short Range ◽  
Three Dimensional ◽  
Resonance Imaging ◽  
Entry Zone ◽  
Root Entry Zone

Abstract OBJECTIVE: This study was performed to investigate the role of postoperative three-dimensional short-range magnetic resonance angiography in the prediction of clinical outcomes after microvascular decompression (MVD) for the treatment of hemifacial spasm. METHODS: We examined pre- and postoperative magnetic resonance imaging scans obtained between March 1999 and May 2000 for 122 patients with hemifacial spasm, to evaluate the degree of detachment of the vascular contact and changes in the positions of offending vessels. The degree of vascular decompression of the facial nerve root was classified into three groups, i.e., contact, partial decompression, or complete decompression. Contact was defined as unresolved compression, as indicated by postoperative three-dimensional short-range magnetic resonance angiography. Partial decompression was defined as incompletely resolved compression; vascular indentation of the facial nerve was improved, but contact with the facial nerve remained. Complete decompression was defined as completely resolved compression. These findings were compared with the surgical findings and clinical outcomes. RESULTS: Of 122 patients with MVD, complete decompression of offending vessels at the root entry zone of the facial nerve was observed for 106 patients (86.9%), partial decompression was observed for 10 patients (8.2%), and contact with offending vessels was observed for 6 patients (4.9%) by using postoperative three-dimensional short-range magnetic resonance angiography. Our study demonstrated that the types of offending vessels affected neither the degree of decompression of the root entry zone of the facial nerve nor surgical outcomes (P > 0.05). Also, there was no significant relationship between the degree of decompression and improvement of symptoms (P > 0.05). Furthermore, there was no significant relationship between the degree of decompression and the timing of symptomatic improvement (P > 0.05). CONCLUSION: Our data suggest that MVD of the facial nerve alone may not be sufficient to resolve symptoms for all patients with hemifacial spasm. Therefore, unknown factors in addition to vascular compression may cause symptoms in certain cases, and it may be necessary to remove those factors, simultaneously with MVD, to obtain symptom resolution.

Tonic neck reflex of the decerebrate cat: a role for propriospinal neurons

1985 ◽  
Vol 54 (4) ◽  
pp. 978-987 ◽  
Author(s):  
E. E. Brink ◽  
I. Suzuki ◽  
S. J. Timerick ◽  
V. J. Wilson
Keyword(s):  
Decerebrate Cat ◽  
Entry Zone ◽  
Root Entry Zone ◽  
Upper Cervical ◽  
Dorsal Columns ◽  
Qualitative Effect ◽  
Neck Rotation ◽  
Propriospinal Neurons ◽  
Tonic Neck Reflex

In decerebrate, acutely labyrinthectomized cats we used neck rotation to study the role of direct upper cervical afferents to the cervical enlargement and of cervical and lumbar propriospinal neurons in the tonic neck reflex. Interruption of the dorsal columns between C4 and C5 had no qualitative effect on the dynamics of the reflex although gain usually increased. Direct upper cervical afferents to the cervical enlargement therefore have no unique role in producing the reflex. Many medially located propriospinal neurons in C4 were modulated by neck rotation. About 40% had axons, mostly crossed, that terminated in the cervical enlargement. The others projected more caudally, some as far as L3-L4 or even the lumbar enlargement. For a population of C4 neurons, including propriospinal neurons, we measured the response vector with combinations of roll and pitch stimuli. These vectors ranged from pitch to roll. Many propriospinal neurons in L3-L4, projecting to the lumbosacral enlargement, were also modulated by neck rotation with a variety of response vectors. Some of these neurons had an ascending projection. As in previous experiments, C4 neurons were modulated by neck rotation after spinal transection rostral to the C1 dorsal root entry zone; a wide variety of response vectors was observed. In contrast, almost no modulated L3-L4 neurons were found in the same experiments. The results suggest a role for propriospinal neurons in the tonic neck reflex. They also demonstrate that responses of lumbar neurons to neck rotation are much more dependent on supraspinal pathways than are those of cervical neurons.

scholarly journals Neurovascular mechanisms of migraine and cluster headache

2017 ◽  
Vol 39 (4) ◽  
pp. 573-594 ◽  
Author(s):  
Jan Hoffmann ◽  
Serapio M Baca ◽  
Simon Akerman
Keyword(s):  
Cluster Headache ◽  
Vascular Response ◽  
Trigeminovascular System ◽  
The Past ◽  
Anatomical Basis ◽  
Calcitonin Gene ◽  
Pituitary Adenylate Cyclase ◽  
Acute Attacks ◽  
Trigeminal Activation

Vascular theories of migraine and cluster headache have dominated for many years the pathobiological concept of these disorders. This view is supported by observations that trigeminal activation induces a vascular response and that several vasodilating molecules trigger acute attacks of migraine and cluster headache in susceptible individuals. Over the past 30 years, this rationale has been questioned as it became clear that the actions of some of these molecules, in particular, calcitonin gene-related peptide and pituitary adenylate cyclase-activating peptide, extend far beyond the vasoactive effects, as they possess the ability to modulate nociceptive neuronal activity in several key regions of the trigeminovascular system. These findings have shifted our understanding of these disorders to a primarily neuronal origin with the vascular manifestations being the consequence rather than the origin of trigeminal activation. Nevertheless, the neurovascular component, or coupling, seems to be far more complex than initially thought, being involved in several accompanying features. The review will discuss in detail the anatomical basis and the functional role of the neurovascular mechanisms relevant to migraine and cluster headache.

scholarly journals Itch and Cough – Similar Role of Sensory Nerves in Their Pathogenesis

2020 ◽  
pp. S43-S54
Author(s):  
T. Pecova ◽  
I. Kocan ◽  
R. Vysehradsky ◽  
R. Pecova
Keyword(s):  
Sensory Nerve ◽  
Small Diameter ◽  
Nerve Fibers ◽  
Sensory Nerves ◽  
Upper Respiratory Tract ◽  
C Fibers ◽  
Afferent Nerves ◽  
Sensory Fibers ◽  
Peripheral Sensory

Itch is the most common chief complaint in patients visiting dermatology clinics and is analogous to cough and also sneeze of the lower and upper respiratory tract, all three of which are host actions trying to clear noxious stimuli. The pathomechanisms of these symptoms are not completely determined. The itch can originate from a variety of etiologies. Itch originates following the activation of peripheral sensory nerve endings following damage or exposure to inflammatory mediators. More than one sensory nerve subtype is thought to subserve pruriceptive itch which includes both unmyelinated C-fibers and thinly myelinated Aδ nerve fibers. There are a lot of mediators capable of stimulating these afferent nerves leading to itch. Cough and itch pathways are mediated by small-diameter sensory fibers. These cough and itch sensory fibers release neuropeptides upon activation, which leads to inflammation of the nerves. The inflammation is involved in the development of chronic conditions of itch and cough. The aim of this review is to point out the role of sensory nerves in the pathogenesis of cough and itching. The common aspects of itch and cough could lead to new thoughts and perspectives in both fields.

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