Satellite potentials on EMG: Neurophysiologic evidence of axonal transection in MS?

Neurology ◽  
2001 ◽  
Vol 57 (6) ◽  
pp. 1126-1128 ◽  
Author(s):  
G. Antonini ◽  
S. Morino ◽  
F. Giubilei ◽  
A. Paolillo ◽  
V. Ceschin ◽  
...  
Keyword(s):  
Axonal Transection

scholarly journals Apolipoprotein E Affects In Vitro Axonal Growth and Regeneration via the MAPK Signaling Pathway

2018 ◽  
Vol 28 (6) ◽  
pp. 691-703 ◽  
Author(s):  
Cheng Yin ◽  
Zong-duo Guo ◽  
Zong-ze He ◽  
Zhen-yu Wang ◽  
Xiao-chuan Sun
Keyword(s):  
Apolipoprotein E ◽  
Signaling Pathway ◽  
Axonal Regeneration ◽  
Axonal Growth ◽  
Mapk Signaling ◽  
Mapk Signaling Pathway ◽  
Axonal Transection ◽  
Apoe Mrna ◽  
P38 Pathway

Following central nervous system injury in mammals, failed axonal regeneration is closely related to dysneuria. Previous studies have shown that the obvious effects of apolipoprotein E (ApoE) on traumatic brain injury (TBI) were associated with an axonal mechanism. However, little information on the actions of ApoE and its isoforms on axonal regeneration following TBI was provided. In our study, the cerebral cortices of ApoE-deficient (ApoE-/-) and wild-type (ApoE+/+) mice were cultured in vitro, and an axonal transection model was established. Interventions included the conditioned medium of astrocytes, human recombinant ApoE2/3/4 isoforms and inhibitors of the JNK/ERK/p38 pathway. Axonal growth and regeneration were evaluated by measuring the maximum distance and area of the axons. The expression levels of β-tubulin III, MAP2, ApoE, p-JNK, p-ERK and p-p38 were detected by immunofluorescence and western blotting. The results showed that ApoE mRNA and protein were expressed in intact axons and regenerated axons. Axonal growth and regeneration were attenuated in ApoE-/- mice but recovered by exogenous ApoE. Human recombinant ApoE3 positively influenced axonal growth and regeneration; these effects were mediated by the JNK/ERK/p38 pathway. These results suggest ApoE and its isoforms may have influenced axonal growth and regeneration via the MAPK signaling pathway in vitro.

Axotomy induces a transient and localized elevation of the free intracellular calcium concentration to the millimolar range

1995 ◽  
Vol 74 (6) ◽  
pp. 2625-2637 ◽  
Author(s):  
N. E. Ziv ◽  
M. E. Spira
Keyword(s):  
Intracellular Calcium ◽  
Calcium Concentration ◽  
Intracellular Calcium Concentration ◽  
Concentration Gradients ◽  
Fura 2 ◽  
Direct Demonstration ◽  
Free Intracellular Calcium ◽  
Axonal Transection ◽  
Transient Elevation

1. Axonal transection triggers a cascade of pathological processes that frequently lead to the degeneration of the injured neuron. It is generally believed that the degenerative process is triggered by an overwhelming influx of calcium through the cut end of the axon. 2. Theoretical considerations and indirect observations suggest that axotomy is followed by an increase in the free intracellular calcium concentration ([Ca2+]i) to the millimolar level. In contrast, only relatively modest and transient elevation in [Ca2+]i to the micromolar level was revealed by recent fura-2 studies. 3. In the current study we used the low-affinity Ca2+ indicator mag-fura-2 to reexamine the spatiotemporal distribution pattern of Ca2+ after axotomy and to map the free intracellular Mg2+ concentration gradients. 4. We report that axotomy elevates [Ca2+]i well beyond the "physiological" range of calcium concentrations, to levels > 1 mM near the tip of the cut axon and to hundreds of micromolars along the axon further away from the cut end. Nevertheless, [Ca2+]i recovers to the control levels within 2-3 min after the resealing of the cut end. 5. A comparison of the behavior of fura-2 and mag-fura-2 in the cytosol of the axotomized neurons reveals that the determination of [Ca2+]i by fura-2 largely underestimates the actual intracellular Ca2+ concentrations. 6. Experiments in which one branch of a bifurcated axon was transected revealed that the elevation in [Ca2+]i is confined to the transected axonal branch and does not spread beyond the bifurcation point. 7. After axotomy, the intracellular Mg2+ concentration equilibrates rapidly with the external concentration and then recovers at a rate somewhat slower than that of [Ca2+]i. 8. To the best of our knowledge, this study is the first direct demonstration that axotomy elevates [Ca2+]i to the millimolar range and that neurons are able to recover from these extreme calcium concentrations.

scholarly journals Cognitive Impairment in Multiple Sclerosis

Folia Medica ◽  
2016 ◽  
Vol 58 (3) ◽  
pp. 157-163 ◽  
Author(s):  
Anastasiya G. Trenova ◽  
Georgi S. Slavov ◽  
Maria G. Manova ◽  
Jana B. Aksentieva ◽  
Lyuba D. Miteva ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Cognitive Impairment ◽  
Cognitive Disorders ◽  
Social Burden ◽  
Immune Mediated ◽  
The Social ◽  
The Central Nervous System ◽  
Axonal Transection ◽  
The Relationship

Abstract Multiple sclerosis (MS) is a socially significant immune-mediated disease, characterized by demyelination, axonal transection and oligodendropathy in the central nervous system. Inflammatory demyelination and neurodegeneration lead to brain atrophy and cognitive deficit in up to 75% of the patients. Cognitive dysfunctions impact significantly patients’ quality of life, independently from the course and phase of the disease. The relationship between pathological brain findings and cognitive impairment is a subject of intensive research. Summarizing recent data about prevalence, clinical specificity and treatment of cognitive disorders in MS, this review aims to motivate the necessity of early diagnosis and complex therapeutic approach to these disturbances in order to reduce the social burden of the disease.

Alterations in neuronal gene expression profiles in response to experimental demyelination and axonal transection

2010 ◽  
Vol 16 (3) ◽  
pp. 303-316 ◽  
Author(s):  
G. Lovas ◽  
JA Nielsen ◽  
KR Johnson ◽  
LD Hudson
Keyword(s):  
Gene Expression ◽  
Multiple Sclerosis ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Neurological Deficits ◽  
Activating Transcription Factor 3 ◽  
Post Intervention ◽  
Neuronal Gene ◽  
Activating Transcription Factor ◽  
Axonal Transection

The main pathological features of multiple sclerosis, demyelination and axonal transection, are considered to cause reversible and irreversible neurological deficits, respectively. This study aimed to separately analyze the effects of these pathological hallmarks on neuronal gene expression in experimental paradigms. The pontocerebellar pathway was targeted with either lysolecithin-induced chemical demyelination or a complete pathway transection (axonal transection) in rats. Transcriptional changes in the pontocerebellar neurons were investigated with microarrays at days 4, 10 and 37 post-intervention, which was confirmed by immunohistochemistry on protein level. A common as well as unique set of injury-response genes was identified. The increased expression of activating transcription factor 3 (Atf3) and thyrotropin-releasing hormone (Trh) in both injury paradigms was validated by immunohistochemistry. The expression of Atf3 in a patient with Marburg’s variant of multiple sclerosis was also detected, also confirming the activation of the Atf3 pathway in a human disease sample. It was concluded that this experimental approach may be useful for the identification of pathways that could be targeted for remyelinative or neuroprotective drug development.

scholarly journals THE RESPONSE OF VENTRAL HORN NEURONS TO AXONAL TRANSECTION

1972 ◽  
Vol 53 (1) ◽  
pp. 24-37 ◽  
Author(s):  
Donald L. Price ◽  
Keith R. Porter
Keyword(s):  
Endoplasmic Reticulum ◽  
Electron Microscope ◽  
Morphological Changes ◽  
Ventral Horn ◽  
Granular Endoplasmic Reticulum ◽  
Neuronal Nucleus ◽  
Axoplasmic Flow ◽  
Cytoplasmic Matrix ◽  
Show Evidence ◽  
Axonal Transection

The morphological changes induced in the frog ventral horn neurons by axonal transection have been studied with the electron microscope. During the first 2 wk after axotomy the neuronal nucleus becomes more translucent and the nucleolus becomes enlarged and less compact. The cisternae of the granular endoplasmic reticulum vesiculate and ribosomes dissociate from membranes. Free ribosomes and polysomes are dispersed in the cytoplasmic matrix. Neurofilaments and neurotubules are increased in number. These structures appear to be important in the regeneration of the axon. It is proposed that neurotubules, neurofilaments, and axoplasmic matrix are synthesized by the free polyribosomes in the chromatolytic neuron. By the fourth postoperative week, the neurons show evidence of recovery. The cytoplasm is filled with profiles of granular endoplasmic reticulum and many intercisternal polysomes. The substances being manufactured by the newly formed granular endoplasmic reticulum are not clearly defined, but probably include elements essential to electrical and chemical conduction of impulses. The significance of these observations in respect to recent studies of axoplasmic flow is discussed.

scholarly journals Remyelination Trials

2021 ◽  
Vol 8 (6) ◽  
pp. e1066
Author(s):  
Alexandr Klistorner ◽  
Michael Barnett
Keyword(s):  
Multiple Sclerosis ◽  
Pharmaceutical Industry ◽  
Tissue Damage ◽  
Axonal Degeneration ◽  
Neuroprotective Strategy ◽  
Axonal Transection

Neuroaxonal loss is believed to underpin the progressive disability that characterizes multiple sclerosis (MS). While focal inflammatory demyelination is a principal cause of acute axonal transection and subsequent axonal degeneration, the gradual attrition of permanently demyelinated axons may also contribute to tissue damage, particularly in the progressive phase of the disease. Therefore, remyelination is considered a putative neuroprotective strategy. In this article, we review the potential pitfalls of remyelination trials, provide a framework for their appropriate design and temper the expectations, at times unrealistic, of researchers, regulators and the pharmaceutical industry.

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