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 Elucidating the Neuropathologic Mechanisms of SARS-CoV-2 Infection

2021 ◽  
Vol 12 ◽  
Author(s):  
Mar Pacheco-Herrero ◽  
Luis O. Soto-Rojas ◽  
Charles R. Harrington ◽  
Yazmin M. Flores-Martinez ◽  
Marcos M. Villegas-Rojas ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Molecular Mechanisms ◽  
Cell Types ◽  
Public Health Emergency ◽  
Converting Enzyme ◽  
Neurological Manifestations ◽  
Brain Areas ◽  
Angiotensin Converting Enzyme 2 ◽  
The Central Nervous System

The current pandemic caused by the new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a public health emergency. To date, March 1, 2021, coronavirus disease 2019 (COVID-19) has caused about 114 million accumulated cases and 2.53 million deaths worldwide. Previous pieces of evidence suggest that SARS-CoV-2 may affect the central nervous system (CNS) and cause neurological symptoms in COVID-19 patients. It is also known that angiotensin-converting enzyme-2 (ACE2), the primary receptor for SARS-CoV-2 infection, is expressed in different brain areas and cell types. Thus, it is hypothesized that infection by this virus could generate or exacerbate neuropathological alterations. However, the molecular mechanisms that link COVID-19 disease and nerve damage are unclear. In this review, we describe the routes of SARS-CoV-2 invasion into the central nervous system. We also analyze the neuropathologic mechanisms underlying this viral infection, and their potential relationship with the neurological manifestations described in patients with COVID-19, and the appearance or exacerbation of some neurodegenerative diseases.

scholarly journals Deletion of the Thrombin Proteolytic Site in Neurofascin 155 Causes Disruption of Nodal and Paranodal Organization

2021 ◽  
Vol 15 ◽  
Author(s):  
Dipankar J. Dutta ◽  
R. Douglas Fields
Keyword(s):  
Nervous System ◽  
Gene Editing ◽  
Cell Types ◽  
Complete Loss ◽  
Spectrometric Analysis ◽  
The Third ◽  
Proteolytic Site ◽  
The Central Nervous System ◽  
Trimolecular Complex ◽  
Unique Domain

In the central nervous system, myelin is attached to the axon in the paranodal region by a trimolecular complex of Neurofascin155 (NF155) in the myelin membrane, interacting with Caspr1 and Contactin1 on the axolemma. Alternative splicing of a single Neurofascin transcript generates several different Neurofascins expressed by several cell types, but NF155, which is expressed by oligodendrocytes, contains a domain in the third fibronectinIII-like region of the molecule that is unique. The immunoglobulin 5–6 domain of NF155 is essential for binding to Contactin1, but less is known about the functions of the NF155-unique third fibronectinIII-like domain. Mutations and autoantibodies to this region are associated with several neurodevelopmental and demyelinating nervous system disorders. Here we used Crispr-Cas9 gene editing to delete a 9 bp sequence of NF155 in this unique domain, which has recently been identified as a thrombin binding site and implicated in plasticity of the myelin sheath. This small deletion results in dysmyelination, eversion of paranodal loops of myelin, substantial enlargement of the nodal gap, a complete loss of paranodal septate junctions, and mislocalization of Caspr1 and nodal sodium channels. The animals exhibit tremor and ataxia, and biochemical and mass spectrometric analysis indicates that while NF155 is transcribed and spliced normally, the NF155 protein is subsequently degraded, resulting in loss of the full length 155 kDa native protein. These findings reveal that this 9 bp region of NF155 in its unique third fibronectinIII-like domain is essential for stability of the protein.

scholarly journals Multifaceted roles of microRNAs: From motor neuron generation in embryos to degeneration in spinal muscular atrophy

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Tai-Heng Chen ◽  
Jun-An Chen
Keyword(s):  
Nervous System ◽  
Neurodegenerative Diseases ◽  
Spinal Muscular Atrophy ◽  
Motor Neuron ◽  
Motor Neurons ◽  
Muscular Atrophy ◽  
Cell Types ◽  
Spinal Motor Neurons ◽  
Potential Applications ◽  
The Central Nervous System

Two crucial questions in neuroscience are how neurons establish individual identity in the developing nervous system and why only specific neuron subtypes are vulnerable to neurodegenerative diseases. In the central nervous system, spinal motor neurons serve as one of the best-characterized cell types for addressing these two questions. In this review, we dissect these questions by evaluating the emerging role of regulatory microRNAs in motor neuron generation in developing embryos and their potential contributions to neurodegenerative diseases such as spinal muscular atrophy (SMA). Given recent promising results from novel microRNA-based medicines, we discuss the potential applications of microRNAs for clinical assessments of SMA disease progression and treatment.

Neuroanatomy and neurophysiology

2021 ◽  
pp. 725-852
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Cervical Vertebrae ◽  
Lymphatic Vessels ◽  
Cell Types ◽  
Cellular Level ◽  
Inhibitory Synapses ◽  
The Central Nervous System ◽  
Emotion Memory ◽  
Different Cell Types

‘Neuroanatomy and neurophysiology’ covers the anatomy and organization of the central nervous system, including the skull and cervical vertebrae, the meninges, the blood and lymphatic vessels, muscles and nerves of the head and neck, and the structures of the eye, ear, and central nervous system. At a cellular level, the different cell types and the mechanism of transmission across synapses are considered, including excitatory and inhibitory synapses. This is followed by a review of the major control and sensory systems (including movement, information processing, locomotion, reflexes, and the main five senses of sight, hearing, touch, taste, and smell). The integration of these processes into higher functions (such as sleep, consciousness and coma, emotion, memory, and ageing) is discussed, along with the causes and treatments of disorders of diseases such as depression, schizophrenia, epilepsy, addiction, and degenerative diseases.

Olfactory Bulb

2017 ◽  
pp. 309-322
Author(s):  
Gordon M. Shepherd ◽  
Michele Migliore ◽  
Francesco Cavarretta
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Visual Cortex ◽  
Olfactory Bulb ◽  
Primary Visual Cortex ◽  
Antennal Lobe ◽  
Cell Types ◽  
Synaptic Interactions ◽  
The Central Nervous System ◽  
Olfactory Input

The olfactory bulb is the site of the first synaptic processing of the olfactory input from the nose. It is present in all vertebrates (except cetaceans) and a the analogous antennal lobe in most invertebrates. With its sharply demarcated cell types and histological layers, and some well-studied synaptic interactions, it is one of the first and clearest examples of the microcircuit concept in the central nervous system. The olfactory bulb microcircuit receives the information in the sensory domain and transforms it into information in the neural domain. Traditionally, it has been considered analogous to the retina in processing its sensory input, but that has been replaced by the view that it is more similar to the thalamus or primary visual cortex in processing its multidimensional input. This chapter describes the main synaptic connections and functional operations and how they provide the output to the olfactory cortex

Mucopolysaccharidosis in Adults

2016 ◽  
Author(s):  
Christian J. Hendriksz ◽  
Francois Karstens
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Autosomal Recessive ◽  
Clinical Symptoms ◽  
Cell Types ◽  
Type Ii ◽  
System P ◽  
Different Types ◽  
The Central Nervous System ◽  
Different Cell Types

There are 8 different types of diseases of the mucopolysaccharides, each caused by a deficiency in one of 10 different enzymes involved in the degradation of glycosaminoglycans (GAGs). Partially degraded GAGs accumulate within the lysosomes of many different cell types and lead to clinical symptoms and excretion of large amounts of GAGs in the urine. Heritability is autosomal recessive except for MPS type II, which is X-linked. The disorders are chronic and progressive and, although the specific types all have their individual features, they share an abundance of clinical similarities. All involve the musculoskeletal, the cardiovascular, the pulmonary and the central nervous system.

Primary Central Nervous System Anaplastic Large Cell Lymphoma is an Unusual Brain Tumour

2014 ◽  
Vol 10 (01) ◽  
pp. 48
Author(s):  
Dionysis Papadatos-Pastos ◽  
James Hall ◽  
Ruth Pettengell ◽  
Leslie R Bridges ◽  
Barry Newell ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Anaplastic Large Cell Lymphoma ◽  
Potential Role ◽  
Cell Lymphoma ◽  
Large Cell ◽  
Anaplastic Lymphoma ◽  
The Central Nervous System ◽  
Large Cell Lymphoma

We present a case of a 64-year-old man who was diagnosed with a primary anaplastic large cell lymphoma of the central nervous system (PCNSAL). He had received radical chemotherapy and radiotherapy for a non-small cell lung cancer (NSCLC) in the past. There is no known association between NSCLC and PCNSAL. We describe the diagnostic and therapeutic challenges associated with these rare intracranial lymphomas and highlight the potential role of newer biological agents in patients with anaplastic lymphoma kinase (ALK-1) positive PCNSAL.

Sign in / Sign up

Export Citation Format

Share Document