scholarly journals Multiple Functions of Draxin/Netrin-1 Signaling in the Development of Neural Circuits in the Spinal Cord and the Brain

2021 ◽  
Vol 15 ◽  
Author(s):  
Giasuddin Ahmed ◽  
Yohei Shinmyo
Keyword(s):  
Spinal Cord ◽  
Axon Guidance ◽  
Neural Circuits ◽  
Neural Circuit ◽  
Deleted In Colorectal Cancer ◽  
Guidance Cue ◽  
Thalamocortical Projections ◽  
The Central Nervous System ◽  
Circuit Formation ◽  
The Brain

Axon guidance proteins play key roles in the formation of neural circuits during development. We previously identified an axon guidance cue, named draxin, that has no homology with other axon guidance proteins. Draxin is essential for the development of various neural circuits including the spinal cord commissure, corpus callosum, and thalamocortical projections. Draxin has been shown to not only control axon guidance through netrin-1 receptors, deleted in colorectal cancer (Dcc), and neogenin (Neo1) but also modulate netrin-1-mediated axon guidance and fasciculation. In this review, we summarize the multifaceted functions of draxin and netrin-1 signaling in neural circuit formation in the central nervous system. Furthermore, because recent studies suggest that the distributions and functions of axon guidance cues are highly regulated by glycoproteins such as Dystroglycan and Heparan sulfate proteoglycans, we discuss a possible function of glycoproteins in draxin/netrin-1-mediated axon guidance.

Perinatal Development of the Medial Nucleus of the Trapezoid Body

2018 ◽  
pp. 244-272
Author(s):  
Shobhana Sivaramakrishnan ◽  
Ashley Brandebura ◽  
Paul Holcomb ◽  
Daniel Heller ◽  
Douglas Kolson ◽  
...  
Keyword(s):  
Axon Guidance ◽  
Neural Circuit ◽  
Neural Cells ◽  
Calyx Of Held ◽  
Medial Nucleus ◽  
Target Neuron ◽  
Circuit Formation ◽  
Key Events ◽  
The Brain ◽  
Trapezoid Body

Bushy cells (BC) of the cochlear nucleus mono-innervate their target neuron, the principal cell of the medial nucleus of the trapezoid body (MNTB), via the calyx of Held (CH) terminal, which is a typically mammalian structure and perhaps the largest nerve terminal in the brain. CH:MNTB innervation has become an attractive model to study neural circuit formation because it forms quickly, passing through stages of competition in mice within 2–4 days. BCs innervate MNTB neurons by E17, but CHs do not begin to grow for another five days (P3). Progress has been made to identify molecular factors for axon guidance, CH growth, and physiological maturation of synaptic partners, but important details remain to be discovered. We summarize key events in CH formation and highlight unresolved issues in molecular and physiological signaling, roles for non-neural cells, and the nature of competition during the first postnatal week.

Central Nerve System Impairment, AMA Guides, Sixth Edition: An Overview

2018 ◽  
Vol 23 (1) ◽  
pp. 10-13
Author(s):  
James B. Talmage ◽  
Jay Blaisdell
Keyword(s):  
Spinal Cord ◽  
Central Nervous System ◽  
Nervous System ◽  
Neurological Impairment ◽  
Sixth Edition ◽  
Central Nerve System ◽  
The Central Nervous System ◽  
The One ◽  
Nerve System ◽  
The Brain

Abstract Injuries that affect the central nervous system (CNS) can be catastrophic because they involve the brain or spinal cord, and determining the underlying clinical cause of impairment is essential in using the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), in part because the AMA Guides addresses neurological impairment in several chapters. Unlike the musculoskeletal chapters, Chapter 13, The Central and Peripheral Nervous System, does not use grades, grade modifiers, and a net adjustment formula; rather the chapter uses an approach that is similar to that in prior editions of the AMA Guides. The following steps can be used to perform a CNS rating: 1) evaluate all four major categories of cerebral impairment, and choose the one that is most severe; 2) rate the single most severe cerebral impairment of the four major categories; 3) rate all other impairments that are due to neurogenic problems; and 4) combine the rating of the single most severe category of cerebral impairment with the ratings of all other impairments. Because some neurological dysfunctions are rated elsewhere in the AMA Guides, Sixth Edition, the evaluator may consult Table 13-1 to verify the appropriate chapter to use.

scholarly journals Spinal vertebrae localization and analysis on disproportionality in curvature using radiography—a comprehensive review

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Joddat Fatima ◽  
Muhammad Usman Akram ◽  
Amina Jameel ◽  
Adeel Muzaffar Syed
Keyword(s):  
Spinal Cord ◽  
Template Matching ◽  
Human Anatomy ◽  
Comprehensive Overview ◽  
Low Contrast ◽  
Active Shape Models ◽  
Harris Corner ◽  
Illumination Changes ◽  
The Central Nervous System ◽  
The Brain

AbstractIn human anatomy, the central nervous system (CNS) acts as a significant processing hub. CNS is clinically divided into two major parts: the brain and the spinal cord. The spinal cord assists the overall communication network of the human anatomy through the brain. The mobility of body and the structure of the whole skeleton is also balanced with the help of the spinal bone, along with reflex control. According to the Global Burden of Disease 2010, worldwide, back pain issues are the leading cause of disability. The clinical specialists in the field estimate almost 80% of the population with experience of back issues. The segmentation of the vertebrae is considered a difficult procedure through imaging. The problem has been catered by different researchers using diverse hand-crafted features like Harris corner, template matching, active shape models, and Hough transform. Existing methods do not handle the illumination changes and shape-based variations. The low-contrast and unclear view of the vertebrae also makes it difficult to get good results. In recent times, convolutional nnural Network (CNN) has taken the research to the next level, producing high-accuracy results. Different architectures of CNN such as UNet, FCN, and ResNet have been used for segmentation and deformity analysis. The aim of this review article is to give a comprehensive overview of how different authors in different times have addressed these issues and proposed different mythologies for the localization and analysis of curvature deformity of the vertebrae in the spinal cord.

Some Points in the Histology of Lymphogenous and Hæmatogenous Toxic Lesions of the Spinal Cord

1908 ◽  
Vol 54 (226) ◽  
pp. 560-561
Author(s):  
David Orr ◽  
R. G. Rows
Keyword(s):  
Spinal Cord ◽  
Central Nervous System ◽  
Nervous System ◽  
Sciatic Nerve ◽  
Morphological Type ◽  
Broth Culture ◽  
Anatomical Distribution ◽  
Tabes Dorsalis ◽  
The Central Nervous System ◽  
The Brain

At a quarterly meeting of this Association held last year at Nottingham, we showed the results of our experiments with toxins upon the spinal cord and brain of rabbits. Our main conclusion was, that the central nervous system could be infected by toxins passing up along the lymph channels of the perineural sheath. The method we employed in our experiments consisted in placing a celloidin capsule filled with a broth culture of an organism under the sciatic nerve or under the skin of the cheek; and we invariably found a resulting degeneration in the spinal cord or brain, according to the situation of the capsule. These lesions we found to be identical in morphological type and anatomical distribution with those found in the cord of early tabes dorsalis and in the brain and cord of general paralysis of the insane. The conclusion suggested by our work was that these two diseases, if toxic, were most probably infections of lymphogenous origin.

scholarly journals Comparisons of neuroinflammation, microglial activation, and degeneration of the locus coeruleus-norepinephrine system in APP/PS1 and aging mice

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Song Cao ◽  
Daniel W. Fisher ◽  
Guadalupe Rodriguez ◽  
Tian Yu ◽  
Hongxin Dong
Keyword(s):  
Spinal Cord ◽  
Locus Coeruleus ◽  
Microglial Activation ◽  
Healthy Aging ◽  
Cell Types ◽  
Norepinephrine System ◽  
Protective Processes ◽  
The Central Nervous System ◽  
Brain And Spinal Cord ◽  
The Brain

Abstract Background The role of microglia in Alzheimer’s disease (AD) pathogenesis is becoming increasingly important, as activation of these cell types likely contributes to both pathological and protective processes associated with all phases of the disease. During early AD pathogenesis, one of the first areas of degeneration is the locus coeruleus (LC), which provides broad innervation of the central nervous system and facilitates norepinephrine (NE) transmission. Though the LC-NE is likely to influence microglial dynamics, it is unclear how these systems change with AD compared to otherwise healthy aging. Methods In this study, we evaluated the dynamic changes of neuroinflammation and neurodegeneration in the LC-NE system in the brain and spinal cord of APP/PS1 mice and aged WT mice using immunofluorescence and ELISA. Results Our results demonstrated increased expression of inflammatory cytokines and microglial activation observed in the cortex, hippocampus, and spinal cord of APP/PS1 compared to WT mice. LC-NE neuron and fiber loss as well as reduced norepinephrine transporter (NET) expression was more evident in APP/PS1 mice, although NE levels were similar between 12-month-old APP/PS1 and WT mice. Notably, the degree of microglial activation, LC-NE nerve fiber loss, and NET reduction in the brain and spinal cord were more severe in 12-month-old APP/PS1 compared to 12- and 24-month-old WT mice. Conclusion These results suggest that elevated neuroinflammation and microglial activation in the brain and spinal cord of APP/PS1 mice correlate with significant degeneration of the LC-NE system.

Does Motor Learning Occur in the Spinal Cord?

1997 ◽  
Vol 3 (5) ◽  
pp. 287-294 ◽  
Author(s):  
V. Reggie Edgerton ◽  
Roland R. Roy ◽  
Ray De Leon Niranjala Tillakaratne ◽  
John A. Hodgson
Keyword(s):  
Spinal Cord ◽  
Motor Task ◽  
Lumbar Spinal Cord ◽  
Lumbosacral Spinal Cord ◽  
Patterns Of Use ◽  
The Neural Network ◽  
The Central Nervous System ◽  
Network Plasticity ◽  
Lumbar Spinal ◽  
The Brain

It is becoming clear that the plasticity of the sensory-motor networks of the adult mammalian lumbosacral spinal cord is much greater than and is more dependent on the specific patterns of use than has been previously assumed. Using a wide variety of experimental paradigms in which the lumbar spinal cord is isolated from the brain, it has been shown that the lumbosacral spinal cord can learn to execute stepping or standing more successfully if that specific task is practiced. It also appears that the sensory input associated with the motor task and/or the manner in which it is interpreted by the spinal cord are important components of the neural network plasticity. Early evidence suggests that several neurotransmitter systems in the spinal cord, to include glycinergic and GABAergic systems, adapt to repetitive use. These studies extend a growing body of evidence suggesting that memory and learning are widely distributed phenomena within the central nervous system. NEUROSCIENTIST 3:287–294, 1997

Neurodevelopment

2020 ◽  
pp. 91-100
Author(s):  
Karl Zilles ◽  
Nicola Palomero-Gallagher
Keyword(s):  
Spinal Cord ◽  
Nervous System ◽  
Neural Tube ◽  
Neural Plate ◽  
Adult Brain ◽  
The Central Nervous System ◽  
Specialized Region ◽  
The Brain ◽  
Rostral Part ◽  
Human Nervous System

The pre- and post-natal development of the human nervous system is briefly described, with special emphasis on the brain, particularly the cerebral and cerebellar cortices. The central nervous system originates from a specialized region of the ectoderm—the neural plate—which develops into the neural tube. The rostral part of the neural tube forms the adult brain, whereas the caudal part (behind the fifth somite) differentiates into the spinal cord. The embryonic brain has three vesicular enlargements: the forebrain, the midbrain, and the hindbrain. The histogenesis of the spinal cord, hindbrain, cerebellum, and cerebral cortex, including myelination, is discussed. The chapter closes with a description of the development of the hemispheric shape and the formation of gyri.

Developmental Overview of Central Neuroanatomy

2017 ◽  
Author(s):  
Peggy Mason
Keyword(s):  
Spinal Cord ◽  
Central Nervous System ◽  
Cerebrospinal Fluid ◽  
Nervous System ◽  
Cerebral Cortex ◽  
Neural Tube ◽  
The Central Nervous System ◽  
Dorsal Telencephalon ◽  
Adult Spinal Cord ◽  
The Brain

The central nervous system develops from a proliferating tube of cells and retains a tubular organization in the adult spinal cord and brain, including the forebrain. Failure of the neural tube to close at the front is lethal, whereas failure to close the tube at the back end produces spina bifida, a serious neural tube defect. Swellings in the neural tube develop into the hindbrain, midbrain, diencephalon, and telencephalon. The diencephalon sends an outpouching out of the cranium to form the retina, providing an accessible window onto the brain. The dorsal telencephalon forms the cerebral cortex, which in humans is enormously expanded by growth in every direction. Running through the embryonic neural tube is an internal lumen that becomes the cerebrospinal fluid–containing ventricular system. The effects of damage to the spinal cord and forebrain are compared with respect to impact on self and potential for improvement.

scholarly journals ACCUMULATION OF ANTIBODIES IN THE CENTRAL NERVOUS SYSTEM

1930 ◽  
Vol 51 (6) ◽  
pp. 889-902 ◽  
Author(s):  
Jules Freund
Keyword(s):  
Spinal Cord ◽  
Central Nervous System ◽  
Cerebrospinal Fluid ◽  
Slow Rate ◽  
Immune Serum ◽  
Brain Extract ◽  
Rapid Rate ◽  
The Central Nervous System ◽  
Brain And Spinal Cord ◽  
The Brain

1. Antibodies can be extracted from the brain and spinal cord of rabbits actively or passively immunized with typhoid bacilli. 2. The titers of the antibodies in the extracts of brain and cord depend upon the titer of the blood serum. In actively immunized rabbits the following numerical relationships exist between the titers of the serum and of these organ extracts: The ratio of the titer of the serum is to the titers of extract of brain and of the spinal cord about as 100 is to 0.8; the titer of the serum is to the titer of the cerebrospinal fluid as 100 is to 0.3. In passively immunized rabbits the titer of the serum is to the titer of brain and spinal-cord extract as 100 is to 0.7. 3. The antibodies recovered from the brain are not due to the presence of blood in it for perfusion of the brain does not reduce its antibody content appreciably. 4. Antibodies penetrate into the spinal fluid from the blood even in the absence of inflammation of the meninges. When the penetration is completed the following numerical relationship exists between the titer of the serum and that of the cerebrospinal fluid: 100 to 0.25. 5. The penetration into the cerebrospinal fluid of antibodies injected intravenously proceeds at a slow rate, being completed only several hours after the immune serum has been injected. The penetration of antibodies into the tissue of the brain occurs at a very rapid rate. It is completed within 15 minutes. 6. It is very unlikely that when the immune serum is injected intravenously the antibodies reach the brain tissue by way of the cerebrospinal fluid, for (1) the antibody titer of the cerebrospinal fluid is lower than that of the brain extract, and (2) antibodies penetrate faster into the tissue of the brain than into the cerebrospinal fluid.

Neurotropic behaviour of Trichobilharzia regenti in ducks and mice

2002 ◽  
Vol 76 (2) ◽  
pp. 137-141 ◽  
Author(s):  
K. Hrádková ◽  
P. Horák
Keyword(s):  
Spinal Cord ◽  
Peripheral Nerves ◽  
Clinical Status ◽  
Inbred Strains ◽  
Blood Capillaries ◽  
The Central Nervous System ◽  
New Type ◽  
The Brain ◽  
Trichobilharzia Regenti

AbstractThe bird nasal schistosome Trichobilharzia regenti is a new agent of cercarial dermatitis. Cercariae are able to penetrate the skin of birds and mammals including man. The parasite then attacks the central nervous system. The present study has shown that schistosomula avoid penetration of blood capillaries and enter the peripheral nerves of the legs of mice and ducks as early as 1 day post-infection (p.i.) and 1.5 days p.i., respectively. These peripheral nerves are used as a route to the spinal cord. In the specific host (duck) schistosomula were found in the spinal cord from 2 days p.i. until 15 days p.i. and in the brain from 12 days p.i. until 18 days p.i. In non-specific hosts (mice; inbred strains BALB/c, hr/hr, SCID) living schistosomula were found in the spinal cord from 2 days p.i. until 21 or 24 days p.i. (depending on the mouse strain) and in the brain of two (BALB/c, SCID) of three inbred strains from 3 days p.i. until 24 days p.i. No correlation was found between the infection dose and clinical status of the experimental hosts. A high affinity of schistosomula for the peripheral nerves was also proved in vitro, suggesting a new type of migratory behaviour in schistosomatids.

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