scholarly journals ДИНАМИКА ИЗМЕНЕНИЙ СТРУКТУР ПАРАНЕВРИЯ В ПОСТНАТАЛЬНОМ ОНТОГЕНЕЗЕ

Innova ◽  
2020 ◽  
pp. 26-28
Author(s):  
Бородина К.А. ◽  
Затолокина М.А. ◽  
Харченко В.В. ◽  
Затолокина М.А. ◽  
Мишина Е.С. ◽  
...  

Currently, there is a lot of literature and research that reflects data on the structure of the peripheral nervous system. However, it should be noted that the results available in the sources do not contain a full range of data on the structural features of paraneural structures and have some contradictions. In addition, data on the morphological features of the structure of the paranephrium of peripheral nerves in ontogenesis are practically absent. This was the beginning of our research, in order to obtain new, more in-depth data on the age-related variability of the peripheral nerve paraneurium.

2020 ◽  
Vol 24 (02) ◽  
pp. 175-180
Author(s):  
Alberto Stefano Tagliafico ◽  
Raquel Prada González ◽  
Federica Rossi ◽  
Bianca Bignotti ◽  
Carlo Martinoli

AbstractThe peripheral nervous system is increasingly being investigated using medical imaging as a complement or in association with electrodiagnostics tests. The application of imaging techniques, such as ultrasound (US) and magnetic resonance imaging (MRI), allows detailed visualization of the peripheral nervous system. According to the European Society of Musculoskeletal Radiology, the use of US for nerve evaluation is strongly encouraged. In addition, the role of US is further enhanced by the wide application of US-guided techniques to diagnose or to treat peripheral nerve disorders.Standard evaluation of peripheral nerves on US usually relies on cross-sectional area evaluation with different cutoff values in the osteofibrous tunnels and outside them. In several anatomical areas, side-to-side comparison is highly recommended because it helps distinguish subtle variations by using the unaffected limb as an internal control.US is widely used to perform US-guided interventional procedures on peripheral nerves. The recent development of radiomics and machine and deep learning applied to peripheral nerves may reveal new insights beyond the capabilities of the human eye. Radiomics may have a role in expanding the diagnostic capabilities of US and MRI in the study of peripheral nerve pathology, especially when the cross-sectional area is not markedly increased.


2018 ◽  
Vol 46 (6) ◽  
pp. 2358-2372 ◽  
Author(s):  
Binbin Deng ◽  
Wenjing Lv ◽  
Weisong Duan ◽  
Yakun Liu ◽  
Zhongyao Li ◽  
...  

Background: Myelination, degeneration and regeneration are implicated in crucial responses to injury in the peripheral nervous system. Considering the progression of amyotrophic lateral sclerosis (ALS), we used the superoxide dismutase 1 (SOD1)-G93A transgenic mouse model of ALS to investigate the effects of mutant SOD1 on the peripheral nerves. Methods: Changes in peripheral nerve morphology were analyzed in SOD1 mutant mice at various stages of the disease by toluidine blue staining and electron microscopy (EM). Schwann cell proliferation and recruitment of inflammatory factors were detected by immunofluorescence staining and quantitative reverse transcription PCR and were compared between SOD1 mutant mice and control mice. Furthermore, western blotting (WB) and TUNEL staining were used to investigate axonal damage and Schwann cell survival in the sciatic nerves of mice in both groups. Results: An analysis of the peripheral nervous system in SOD1-G93A mice revealed the following novel features: (i) Schwann cells and axons in mutant mice underwent changes that were similar to those seen in the control mice during the early development of peripheral nerves. (ii) The peripheral nerves of SOD1-G93A mice developed progressive neuropathy, which presented as defects in axons and myelin, leading to difficulty in walking and reduced locomotor capacity at a late stage of the disease. (iii) Macrophages were recruited and accumulated, and nerve injury and a deficit in the blood-nerve barrier were observed. (iv) Proliferation and the inflammatory micro-environment were inhibited, which impaired the regeneration and remyelination of axons after crush injury in the SOD1-G93A mice. Conclusions: The mutant human SOD1 protein induced axonal and myelin degeneration during the progression of ALS and participated in axon remyelination and regeneration in response to injury.


Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 37-37
Author(s):  
Kristin Komnick ◽  
Jennifer May ◽  
Pouneh Kermani ◽  
Sreemanti Basu ◽  
Irene Hernandez ◽  
...  

Blood cell production is regulated by peripheral nerve fibers that innervate the bone marrow. However, little is known about the development or maintenance of hematopoietic innervation. Schwann cells (SCs) are the primary axon 'support cells' of the peripheral nervous system (PNS), and abnormal SC development is sufficient to impair peripheral nerve function. SCs are also the primary repair cell for the PNS which makes them an attractive therapeutic target for normalization of drug or malignancy-induced 'hematopoietic neuropathy'. We hypothesized that neural regulation of hematopoiesis is dependent on SC development. To test this hypothesis, we used the Myelin Protein Zero-Cre (MP0-Cre); Lamc1fl/fl mouse line in which laminin-γ1 expression is deleted from SC precursors and their progeny1. Early SC maturation is dependent on autocrine SC precursor-derived molecules such as laminin-γ1. SC differentiation arrests prior to axon sorting and ensheathment in MP0-Cre; Lamc1fl/fl mice, and causes a global peripheral neuropathy that persists throughout the lifetime of the animal. Preliminary hematopoietic analysis of 'steady state' MP0-Cre; Lamc1fl/fl and littermate control mice has shown the following: (1) MP0-Cre; Lamc1fl/fl bone marrow is innervated, and Cre-mediated gene recombination occurs in cells immunophenotypically consistent with SCs throughout the peripheral nervous system, including those in the bone marrow; (2) MP0-Cre; Lamc1fl/fl mice are lymphopenic but not neutropenic; (3) MP0-Cre; Lamc1fl/fl mice have significantly reduced spleen size and cellularity; and (4) MP0-Cre; Lamc1fl/fl bone marrow has an ~50% reduction in Lin-Sca-1+Kit+(LSK) cells (measured as a percentage of the Lin- compartment of the bone marrow). These results are consistent with earlier work by our groups in which we found that global Lamc1 gene deletion in adult mice induced peripheral blood lymphopenia, reduced spleen size, and a niche-dependent reduction of lymphoid progenitor and precursor cells that was secondary to increased lymphoid precursor cell apoptosis and reduced proliferation (UBC-CreERT2; Lamc1fl/fl mouse line). As with the SC-specific laminin-γ1 deficient mice, myelopoiesis was preserved in the UBC-CreERT2; Lamc1fl/fl mice. Based on results from MP0-Cre; Lamc1fl/fl and UBC-CreERT2; Lamc1fl/fl mice, we conclude that early lymphoid but not myeloid development requires laminin-γ1 expression by MP0-Cre-targetted niche cells, i.e. Schwann Cells. Our results are consistent with reports from other labs that hematopoietic sympathetic neuropathy promotes aberrant myeloid expansion at the expense of lymphopoiesis2. Going forward, we will determine whether lymphopoietic development is dependent on global versus laminin-specific SC-derived cues, and whether these signals are transmitted directly between SCs and lymphoid biased HSPCs or indirectly via other components of the hematopoietic niche. We anticipate that this line of investigation will provide molecular insights and pharmacologic targets for prevention and or normalization of the 'hematopoietic neuropathy' induced by diabetes, aging, neurotoxic chemotherapies and myeloid malignancies. REFERENCES: 1 Yu, W. M., Feltri, M. L., Wrabetz, L., Strickland, S. & Chen, Z. L. Schwann cell-specific ablation of laminin gamma1 causes apoptosis and prevents proliferation. J Neurosci25, 4463-4472, doi:10.1523/JNEUROSCI.5032-04.2005 (2005). 2 Maryanovich, M. et al. Adrenergic nerve degeneration in bone marrow drives aging of the hematopoietic stem cell niche. Nat Med24, 782-791, doi:10.1038/s41591-018-0030-x (2018). Disclosures No relevant conflicts of interest to declare.


2017 ◽  
Vol 12 (01) ◽  
pp. e1-e6 ◽  
Author(s):  
Yigit Uyanikgil ◽  
Turker Cavusoglu ◽  
Kubilay Kılıc ◽  
Gurkan Yigitturk ◽  
Servet Celik ◽  
...  

This review summarizes the role of melatonin (MLT) in defense against toxic-free radicals and its novel effects in the development of the nervous system, and the effect of endogenously produced and exogenously administered MLT in reducing the degree of tissue and nerve injuries. MLT was recently reported to be an effective free radical scavenger and antioxidant. Since endogenous MLT levels fall significantly in senility, these findings imply that the loss of this antioxidant could contribute to the incidence or severity of some age-related neurodegenerative diseases. Considering the high efficacy of MLT in overcoming much of the injury not only to the peripheral nerve but also to other organs, clinical trials for this purpose should be seriously considered.


Author(s):  
Robert J. Spinner

Peripheral nerve is an important and historical part of neurosurgery. It also has been a major focus of both the written and oral examinations administered by the American Board of Neurological Surgeons (ABNS). The Oral Board candidate must be prepared for potentially one to several questions on some of the common disorders of the peripheral nervous system. In this chapter, a systematic approach to peripheral nerve problems is presented. Common areas that might be examined include tumors, injuries, inflammatory conditions, entrapments, and neuropathic pain. Five cases are illustrated, and “pearls” are provided. At the conclusion of the chapter are nine photographs representing problems the Oral Board candidate should be able to identify and answer.


2019 ◽  
Vol 3 (Supplement_1) ◽  
pp. S107-S107
Author(s):  
Stacy A Hussong ◽  
Veronica Galvan

Abstract With age, peripheral nerves undergo demyelination along with overall decrease in peripheral nerve conduction velocity in both sensory and motor nerves. Loss of innervation in muscles is thought to be a major factor in causing age-related sarcopenia including a decrease in muscle function. Dietary restriction attenuates the detrimental effects of aging in mice. Reduction of mTOR signaling is hypothesized to have overlapping mechanisms with dietary restriction. Furthermore, inhibition of mTOR via rapamycin treatment is known to extend lifespan in mice as well as improve peripheral nerve myelination. Therefore, I hypothesized that reducing mTORC1 signaling in neurons would be able to ameliorate the deleterious effects of aging in peripheral nerves. An overall decrease in nerve conduction velocity was observed in both tail sensory and sural nerves with age (15 vs. 30 months). In neuronal mTORC1 KD animals, there was an age-related preservation of both sural and sciatic nerve conduction. Rapamycin treatment produced similar effects with a trend towards increased sciatic nerve conduction velocity in rapamycin-treated wild-type mice at 19 months. The preserve sciatic nerve conduction velocity could be partially explained by preserved myelination. Neuronal mTORC1 knockdown animals had more myelin in the sciatic nerve at 30 mo. as compared to age-matched controls. Overall, these data indicate that mTORC1 signaling plays a role in the age-related decline in peripheral nerve myelination as well as nerve conduction velocity. Future therapeutics could utilize rapamycin or other rapalogs to combat the decline in peripheral nerve function associated with age and other diseases as well.


Author(s):  
Tim Godel ◽  
Philipp Bäumer ◽  
Said Farschtschi ◽  
Klaus Püschel ◽  
Barbara Hofstadler ◽  
...  

Abstract Purpose To examine long-term alterations of the dorsal root ganglia (DRG) and the peripheral nerve in patients with neurofibromatosis type 2 (NF2) by in vivo high-resolution magnetic resonance neurography (MRN) and their correlation to histology. Methods In this prospective study the lumbosacral DRG, the right sciatic, tibial, and peroneal nerves were examined in 6 patients diagnosed with NF2 and associated polyneuropathy (PNP) by a standardized MRN protocol at 3 T. Volumes of DRG L3–S2 as well as peripheral nerve lesions were assessed and compared to follow-up examinations after 14–100 months. In one patient, imaging findings were further correlated to histology. Results Follow-up MRN examination showed a non-significant increase of volume for the DRG L3: +0.41% (p = 0.10), L4: +22.41% (p = 0.23), L5: +3.38% (p = 0.09), S1: +10.63% (p = 0.05) and S2: +1.17% (p = 0.57). Likewise, peripheral nerve lesions were not significantly increased regarding size (2.18 mm2 vs. 2.15 mm2, p = 0.89) and number (9.00 vs. 9.33, p = 0.36). Histological analyses identified schwannomas as the major correlate of both DRG hyperplasia and peripheral nerve lesions. For peripheral nerve microlesions additionally clusters of onion-bulb formations were identified. Conclusion Peripheral nervous system alterations seem to be constant or show only a minor increase in adult NF2. Thus, symptoms of PNP may not primarily attributed to the initial schwannoma growth but to secondary long-term processes, with symptoms only occurring if a certain threshold is exceeded. Histology identified grouped areas of Schwann cell proliferations as the correlate of DRG hyperplasia, while for peripheral nerve lesions different patterns could be found.


2019 ◽  
Vol 20 (17) ◽  
pp. 4192
Author(s):  
Venkat Krishnan Sundaram ◽  
Charbel Massaad ◽  
Julien Grenier

Recent research in the last decade has sought to explore the role and therapeutic potential of Liver X Receptors (LXRs) in the physiology and pathologies of the Peripheral Nervous System. LXRs have been shown to be important in maintaining the redox homeostasis in peripheral nerves for proper myelination, and they regulate ER stress in sensory neurons. Furthermore, LXR stimulation has a positive impact on abrogating the effects of diabetic peripheral neuropathy and obesity-induced allodynia in the Peripheral Nervous System (PNS). This review details these findings and addresses certain important questions that are yet to be answered. The potential roles of LXRs in different cells of the PNS are speculated based on existing knowledge. The review also aims to provide important perspectives for further research in elucidating the role of LXRs and assessing the potential of LXR based therapies to combat pathologies of the Peripheral Nervous System.


Sign in / Sign up

Export Citation Format

Share Document