scholarly journals An alternative mechanism of early nodal clustering and myelination onset in GABAergic neurons of the central nervous system

2019 ◽  
Author(s):  
Melina Thetiot ◽  
Sean A. Freeman ◽  
Thomas Roux ◽  
Anne-Laure Dubessy ◽  
Marie-Stéphane Aigrot ◽  
...  
Keyword(s):  
Molecular Motors ◽  
Node Of Ranvier ◽  
Gabaergic Neurons ◽  
Alternative Mechanism ◽  
Imaging Approach ◽  
The Central Nervous System ◽  
Saltatory Conduction ◽  
Shed Light ◽  
Node Formation

SUMMARYIn vertebrates, fast saltatory conduction along myelinated axons relies on the node of Ranvier. How nodes assemble on CNS neurons is not yet fully understood. We recently highlighted that clusters similar to nodes can form prior to myelin deposition in hippocampal GABAergic neurons and are associated with increased conduction velocity. Here, we used a live imaging approach to characterize the intrinsic mechanisms underlying the assembly of these early clusters. We first demonstrated that their components can partially pre-assemble prior to membrane targeting and determined the molecular motors involved in their trafficking. We then demonstrated the key role of the protein β2Nav for clustering initiation. We further unraveled the fate of these early clusters, by showing that they participate in node formation, but also have an unexpected role in guiding oligodendrocyte processes prior to myelin deposition. Altogether our results shed light on an alternative mechanism of nodal clustering and myelination onset.

Phosphatases and solid tumors: focus on glioblastoma initiation, progression and recurrences

2017 ◽  
Vol 474 (17) ◽  
pp. 2903-2924 ◽  
Author(s):  
Matthias Dedobbeleer ◽  
Estelle Willems ◽  
Stephen Freeman ◽  
Arnaud Lombard ◽  
Nicolas Goffart ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Prostate Cancer ◽  
Solid Tumors ◽  
Primary Cancer ◽  
Key Factors ◽  
Cellular Functions ◽  
The Central Nervous System ◽  
Differentiation And Proliferation ◽  
Shed Light

Phosphatases and cancer have been related for many years now, as these enzymes regulate key cellular functions, including cell survival, migration, differentiation and proliferation. Dysfunctions or mutations affecting these enzymes have been demonstrated to be key factors for oncogenesis. The aim of this review is to shed light on the role of four different phosphatases (PTEN, PP2A, CDC25 and DUSP1) in five different solid tumors (breast cancer, lung cancer, pancreatic cancer, prostate cancer and ovarian cancer), in order to better understand the most frequent and aggressive primary cancer of the central nervous system, glioblastoma.

scholarly journals Rows of dimeric-particles within the axolemma and juxtaposed particles within glia, incorporated into a new model for the paranodal glial-axonal junction at the node of Ranvier.

1980 ◽  
Vol 84 (2) ◽  
pp. 261-280 ◽  
Author(s):  
C A Wiley ◽  
M H Ellisman
Keyword(s):  
Nervous System ◽  
Potential Role ◽  
Freeze Fracture ◽  
Node Of Ranvier ◽  
Cell Types ◽  
Specimen Preparation ◽  
New Findings ◽  
Intricate Mechanism ◽  
The Central Nervous System ◽  
Saltatory Conduction

Using freeze-fracture techniques, we have analyzed the glial-axonal junction (GAJ) between Schwann cells and axons in the peripheral nervous system, and between oligodendrocytes and axons in the central nervous system of the rat. We have identified a new set of dimeric-particles arranged in circumferential rows within the protoplasmic fracture faces (P-faces) of the paranodal axolemma in the region of glial-axonal juxtaposition. These particles, 260 A in length, composed of two 115-A subunits, are observed in both aldehyde-fixed and nonfixed preparations. The rows of dimeric-particles within the axonal P-face are associated with complementary rows of pits within the external fracture face (E-face) of the paranodal axolemma. These axonal particles are positioned between rows of 160-A particles that occur in both fracture faces of the glial loops in the same region. We observed, in addition to these previously described 160-A particles, a new set of 75-A glial particles within the glial P-faces of the GAJ. These 75-A particles form rows that are centered between the rows of 160-A particles and are therefore superimposed over the rows of dimeric-particles within the paranodal axolemma. Our new findings are interpreted with respect to methods of specimen preparation as well as to a potential role for the paranodal organ in saltatory conduction. We conclude that this particle-rich junction between axon and glia could potentially provide an intricate mechanism for ion exchange between these two cell types.

scholarly journals An alternative mechanism of early nodal clustering and myelination onset in GABAergic neurons of the central nervous system

Glia ◽  
2020 ◽  
Vol 68 (9) ◽  
pp. 1891-1909 ◽  
Author(s):  
Melina Thetiot ◽  
Sean A. Freeman ◽  
Thomas Roux ◽  
Anne‐Laure Dubessy ◽  
Marie‐Stéphane Aigrot ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Gabaergic Neurons ◽  
Alternative Mechanism ◽  
The Central Nervous System

scholarly journals Microglia: An Active Player in the Regulation of Synaptic Activity

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Kyungmin Ji ◽  
Jeremy Miyauchi ◽  
Stella E. Tsirka
Keyword(s):  
Central Nervous System ◽  
Critical Role ◽  
Innate Immune ◽  
Synaptic Activity ◽  
Cell Type ◽  
Synaptic Development ◽  
Active Player ◽  
The Central Nervous System ◽  
Shed Light

Synaptic plasticity is critical for elaboration and adaptation in the developing and developed brain. It is well established that astrocytes play an important role in the maintenance of what has been dubbed “the tripartite synapse”. Increasing evidence shows that a fourth cell type, microglia, is critical to this maintenance as well. Microglia are the resident macrophages of the central nervous system (CNS). Because of their well-characterized inflammatory functions, research has primarily focused on their innate immune properties. The role of microglia in the maintenance of synapses in development and in homeostasis is not as well defined. A number of significant findings have shed light on the critical role of microglia at the synapse. It is becoming increasingly clear that microglia play a seminal role in proper synaptic development and elimination.

The Role of Zinc in Thyroid Hormones Metabolism

2019 ◽  
Vol 89 (1-2) ◽  
pp. 80-88 ◽  
Author(s):  
Juliana Soares Severo ◽  
Jennifer Beatriz Silva Morais ◽  
Taynáh Emannuelle Coelho de Freitas ◽  
Ana Letícia Pereira Andrade ◽  
Mayara Monte Feitosa ◽  
...  
Keyword(s):  
Thyroid Hormones ◽  
Scientific Evidence ◽  
Thyroid Stimulating Hormone ◽  
Zinc Transporters ◽  
Serum Concentrations ◽  
Metabolic Adaptations ◽  
Serum T3 ◽  
Regulatory Effects ◽  
Shed Light

Abstract. Thyroid hormones play an important role in body homeostasis by facilitating metabolism of lipids and glucose, regulating metabolic adaptations, responding to changes in energy intake, and controlling thermogenesis. Proper metabolism and action of these hormones requires the participation of various nutrients. Among them is zinc, whose interaction with thyroid hormones is complex. It is known to regulate both the synthesis and mechanism of action of these hormones. In the present review, we aim to shed light on the regulatory effects of zinc on thyroid hormones. Scientific evidence shows that zinc plays a key role in the metabolism of thyroid hormones, specifically by regulating deiodinases enzymes activity, thyrotropin releasing hormone (TRH) and thyroid stimulating hormone (TSH) synthesis, as well as by modulating the structures of essential transcription factors involved in the synthesis of thyroid hormones. Serum concentrations of zinc also appear to influence the levels of serum T3, T4 and TSH. In addition, studies have shown that Zinc transporters (ZnTs) are present in the hypothalamus, pituitary and thyroid, but their functions remain unknown. Therefore, it is important to further investigate the roles of zinc in regulation of thyroid hormones metabolism, and their importance in the treatment of several diseases associated with thyroid gland dysfunction.

The Adult as Foe or Friend?: Childism in Guus Kuijer's Criticism and Fiction

2013 ◽  
Vol 6 (2) ◽  
pp. 205-217 ◽  
Author(s):  
Vanessa Joosen
Keyword(s):  
Children's Literature ◽  
Children’S Literature ◽  
Age Groups ◽  
Children's Books ◽  
Children’S Books ◽  
Memorial Award ◽  
Adult Reader ◽  
Shed Light ◽  
Selection Of

Compared to the attention that children's literature scholars have paid to the construction of childhood in children's literature and the role of adults as authors, mediators and readers of children's books, few researchers have made a systematic study of adults as characters in children's books. This article analyses the construction of adulthood in a selection of texts by the Dutch author and Astrid Lindgren Memorial Award winner Guus Kuijer and connects them with Elisabeth Young-Bruehl's recent concept of ‘childism’ – a form of prejudice targeted against children. Whereas Kuijer published a severe critique of adulthood in Het geminachte kind [The despised child] (1980), in his literary works he explores a variety of positions that adults can take towards children, with varying degrees of childist features. Such a systematic and comparative analysis of the way grown-ups are characterised in children's texts helps to shed light on a didactic potential that materialises in different adult subject positions. After all, not only literary and artistic aspects of children's literature may be aimed at the adult reader (as well as the child), but also the didactic aspect of children's books can cross over between different age groups.

Tax evasion in the medical profession An Empirical Study in the General Tax Authority in Iraq

2019 ◽  
Vol 118 (11) ◽  
pp. 80-88
Author(s):  
Ramyar Rzgar Ahmed ◽  
Hawkar Qasim Birdawod ◽  
S. Rabiyathul Basariya
Keyword(s):  
Tax Evasion ◽  
Income Tax ◽  
Medical Profession ◽  
Great Influence ◽  
Tax Law ◽  
Degree Of Confidence ◽  
Medical Professions ◽  
Shed Light

The study dealt with tax evasion in the medical profession, where the problem was the existence of many cases of tax evasion, especially tax evasion in the income tax of medical professions. The aim of the study is to try to shed light on the phenomenon of tax evasion and the role of the tax authority in the development of controls and means that reduce the phenomenon of tax evasion. The most important results of the low level of tax awareness and lack of knowledge of the tax law and the unwillingness to read it and the sense of taxpayers unfairness of the tax all lead to an increase in cases of tax evasion and in suggested tightening control and follow-up on the offices of auditors, through the investigation and auditing The reports of certified accountants and the use of computers for this purpose in order to raise the degree of confidence in these reports and bring them closer to the required truth and coordination and cooperation with the Union of Accountants and Auditors and inform them about each case of violations of the auditors and accountants N because of its great influence in the rejection of the organization of the accounts and not to ratify fake accounts lead to show taxpayers accounts on a non-truth in order to tax evasion.

Juvenile xanthogranuloma of the subdural spaces mimicking chronic hematoma with positive FDG uptake on PET: case report

2020 ◽  
Vol 26 (4) ◽  
pp. 449-453
Author(s):  
Jacob A. Kahn ◽  
Jeffrey T. Waltz ◽  
Ramin M. Eskandari ◽  
Cynthia T. Welsh ◽  
Michael U. Antonucci
Keyword(s):  
Potential Role ◽  
Response To Treatment ◽  
Juvenile Xanthogranuloma ◽  
Imaging Features ◽  
Limited Information ◽  
Advanced Imaging ◽  
Systemic Involvement ◽  
The Central Nervous System ◽  
Infancy And Early Childhood

The authors report an unusual presentation of juvenile xanthogranuloma (JXG), a non–Langerhans cell histiocytosis of infancy and early childhood. This entity typically presents as a cutaneous head or neck nodule but can manifest with more systemic involvement including in the central nervous system. However, currently there is limited information regarding specific imaging features differentiating JXG from other neuropathological entities, with diagnosis typically made only after tissue sampling. The authors reviewed the initial images of a young patient with shunt-treated hydrocephalus and enlarging, chronic, extraaxial processes presumed to reflect subdural collections from overshunting, and they examine the operative discovery of a mass lesion that was pathologically proven to be JXG. Their results incorporate the important associated histological and advanced imaging features, including previously unreported metabolic activity on FDG PET. Ultimately, the case underscores the need to consider JXG in differential diagnoses of pediatric intracranial masses and highlights the potential role of PET in the initial diagnosis and response to treatment.

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