scholarly journals Status Spongiosis, Optic Neuropathy, and Retinal Degeneration in Helichrysum argyrosphaerum Poisoning in Sheep and a Goat

1996 ◽  
Vol 33 (5) ◽  
pp. 495-502 ◽  
Author(s):  
J. J. van der Lugt ◽  
J. Olivier ◽  
P. Jordain
Keyword(s):  
White Matter ◽  
Blood Vessel ◽  
Glial Cells ◽  
Optic Neuropathy ◽  
Microscopic Examination ◽  
Photoreceptor Outer Segments ◽  
Pigmented Epithelium ◽  
Cerebellar Peduncles ◽  
The Brain ◽  
Ultrastructural Finding

Lesions of natural Helichrysum argyrosphaerum poisoning were studied in eight sheep and one goat. Light microscopic examination revealed widespread, bilaterally symmetrical status spongiosis of the white matter of the brain consistently present in the subependymal area adjacent to the lateral ventricles, cerebellar peduncles, and brain stem in all animals. In three animals, the ultrastructural finding of intramyelinic vacuolation due to splitting of the myelin lamellae at the intraperiod lines indicated myelin edema. There was also mild distension of perivascular and extracellular spaces in the severely affected areas. Significant changes were absent in neurons, glial cells, axons, or blood vessel walls. Myelin edema associated with degeneration and loss of axons and myelin and astrocytic gliosis was present in the intraorbital and intracranial portions of the optic nerves. In the intracanalicular portions of the nerves in three animals that were studied, more chronic lesions consisting of fibrosis and atrophy of the nerve suggested that the optic neuropathy follows compression of the nerve in the optic canal as a result of myelin edema. The toxic principle of the plant also caused a degenerative retinopathy in five animals. The essential histopathologic change was degeneration and loss of the photoreceptor outer segments predominantly in the nontapetal retina. These retinal lesions were associated with hyperplasia and hypertrophy and with migration of the pigmented epithelium, focal retinal separation, and depletion and loss of the nuclear layers.

THE METABOLISM OF NORMAL BRAIN AND HUMAN GLIOMAS IN RELATION TO CELL TYPE AND DENSITY

1955 ◽  
Vol 33 (3) ◽  
pp. 395-403 ◽  
Author(s):  
Irving H. Heller ◽  
K. A. C. Elliott
Keyword(s):  
Cerebral Cortex ◽  
White Matter ◽  
Brain Tumors ◽  
Corpus Callosum ◽  
Oxygen Uptake ◽  
Glial Cells ◽  
Cerebellar Cortex ◽  
Unit Weight ◽  
Uptake Rates ◽  
The Brain

Per unit weight, cerebral and cerebellar cortex respire much more actively than corpus callosum. The rate per cell nucleus is highest in cerebral cortex, lower in corpus callosum, and still lower in cerebellar cortex. The oxygen uptake rates of the brain tumors studied, with the exception of an oligodendroglioma, were about the same as that of white matter on the weight basis but lower than that of cerebral cortex or white matter on the cell basis. In agreement with previous work, an oligodendroglioma respired much more actively than the other tumors. The rates of glycolysis of the brain tumors per unit weight were low but, relative to their respiration rate, glycolysis was higher than in normal gray or white matter. Consideration of the figures obtained leads to the following tentative conclusions: Glial cells of corpus callosum respire more actively than the neurons of the cerebellar cortex. Neurons of the cerebral cortex respire on the average much more actively than neurons of the cerebellar cortex or glial cells. Considerably more than 70% of the oxygen uptake by cerebral cortex is due to neurons. The oxygen uptake rates of normal oligodendroglia and astrocytes are probably about the same as the rates found per nucleus in an oligodendroglioma and in astrocytomas; oligodendroglia respire much more actively than astrocytes.

The Cerebrum, Cerebellum, & Cognitive Disorders

Neuroanatomy ◽  
2017 ◽  
pp. 287-340
Author(s):  
Adam J Fisch
Keyword(s):  
White Matter ◽  
Cognitive Disorders ◽  
Sylvian Fissure ◽  
Arterial Supply ◽  
Cerebral White Matter ◽  
Brodmann Areas ◽  
Cerebellar Peduncles ◽  
Key Features ◽  
The Brain ◽  
Cerebellar Disorders

This chapter focuses on the cerebral lobes and some additional key features of the superior and inferior surfaces of the brain, as well as on the structures of the cerebellum. Instructions are provided on how to draw the multiple lobes and surfaces of the cerebrum, gyri, sulci, insula, Sylvian fissure, Brodmann areas, neocortical layers, cerebellum, cerebellar peduncles, the corticopontocerebellar pathway, cerebellar midline structures, arterial supply, cerebral white matter, and commissural fibers. Also discussed are features of histology of neurons and glia and cerebellar histology. Cerebral and cerebellar disorders are also presented, including cognitive disorders, apraxia, and neglect.

Neuron–glia synapses in the brain: properties, diversity and functions of NG2 glia

e-Neuroforum ◽  
2015 ◽  
Vol 21 (3) ◽  
Author(s):  
Christian Steinhäuser ◽  
Dirk Dietrich
Keyword(s):  
White Matter ◽  
Glial Cells ◽  
Temporal Integration ◽  
Brain Regions ◽  
Gabaergic Neurons ◽  
Cell Type ◽  
Transmitter Receptors ◽  
Ng2 Proteoglycan ◽  
The Impact ◽  
The Brain

AbstractAlthough NG2 glial cells represent a frequent glial cell type in the brain, characterized by expression of the NG2 proteoglycan, the functional impact of these cells is still enigmatic. A large proportion of NG2 glia are proliferatively active throughout life. These cells express a plethora of ion channels and transmitter receptors, which enable them to detect neuronal activity. Intriguingly, NG2 glial cells receive synaptic input from glutamatergic and GABAergic neurons. Since these postsynaptic glial currents are very small, their spatial and temporal integration might play an important role. In white matter, most NG2 glial cells differentiate into oligodendrocytes and this process might be influenced through the activity of the aforementioned neuron-glia synapses. Increasing evidence suggests that the properties of NG2 glia vary across brain regions; however, the impact of this variability is not understood yet.

THE METABOLISM OF NORMAL BRAIN AND HUMAN GLIOMAS IN RELATION TO CELL TYPE AND DENSITY

1955 ◽  
Vol 33 (1) ◽  
pp. 395-403 ◽  
Author(s):  
Irving H. Heller ◽  
K. A. C. Elliott
Keyword(s):  
Cerebral Cortex ◽  
White Matter ◽  
Brain Tumors ◽  
Corpus Callosum ◽  
Oxygen Uptake ◽  
Glial Cells ◽  
Cerebellar Cortex ◽  
Unit Weight ◽  
Uptake Rates ◽  
The Brain

Per unit weight, cerebral and cerebellar cortex respire much more actively than corpus callosum. The rate per cell nucleus is highest in cerebral cortex, lower in corpus callosum, and still lower in cerebellar cortex. The oxygen uptake rates of the brain tumors studied, with the exception of an oligodendroglioma, were about the same as that of white matter on the weight basis but lower than that of cerebral cortex or white matter on the cell basis. In agreement with previous work, an oligodendroglioma respired much more actively than the other tumors. The rates of glycolysis of the brain tumors per unit weight were low but, relative to their respiration rate, glycolysis was higher than in normal gray or white matter. Consideration of the figures obtained leads to the following tentative conclusions: Glial cells of corpus callosum respire more actively than the neurons of the cerebellar cortex. Neurons of the cerebral cortex respire on the average much more actively than neurons of the cerebellar cortex or glial cells. Considerably more than 70% of the oxygen uptake by cerebral cortex is due to neurons. The oxygen uptake rates of normal oligodendroglia and astrocytes are probably about the same as the rates found per nucleus in an oligodendroglioma and in astrocytomas; oligodendroglia respire much more actively than astrocytes.

Characterization of Ischemic Stroke in CT Images using Image Processing

2017 ◽  
Vol 7 (9) ◽  
pp. 18
Author(s):  
Amal Alzain ◽  
Suhaib Alameen ◽  
Rani Elmaki ◽  
Mohamed E. M. Gar-Elnabi
Keyword(s):  
Ischemic Stroke ◽  
White Matter ◽  
Classification Accuracy ◽  
Ct Images ◽  
Gray Level ◽  
Level Variation ◽  
Interactive Data ◽  
The Brain ◽  
Brain Tissues

This study concern to characterize the brain tissues to ischemic stroke, gray matter, white matter and CSF using texture analysisto extract classification features from CT images. The First Order Statistic techniques included sevenfeatures. To find the gray level variation in CT images it complements the FOS features extracted from CT images withgray level in pixels and estimate the variation of thesubpatterns. analyzing the image with Interactive Data Language IDL software to measure the grey level of images. The results show that the Gray Level variation and   features give classification accuracy of ischemic stroke 97.6%, gray matter95.2%, white matter 97.3% and the CSF classification accuracy 98.0%. The overall classification accuracy of brain tissues 97.0%.These relationships are stored in a Texture Dictionary that can be later used to automatically annotate new CT images with the appropriate brain tissues names.

What Has Direct Cortical and Subcortical Electrostimulation Taught Us about Neurolinguistics?

2019 ◽  
pp. 185-211
Author(s):  
Hugues Duffau
Keyword(s):  
White Matter ◽  
Large Scale ◽  
Functional Neuroimaging ◽  
Great Accuracy ◽  
Subcortical White Matter ◽  
Cerebral Lesions ◽  
Physiological Basis ◽  
Postoperative Mri ◽  
The Brain

Investigating the neural and physiological basis of language is one of the most important challenges in neurosciences. Direct electrical stimulation (DES), usually performed in awake patients during surgery for cerebral lesions, is a reliable tool for detecting both cortical and subcortical (white matter and deep grey nuclei) regions crucial for cognitive functions, especially language. DES transiently interacts locally with a small cortical or axonal site, but also nonlocally, as the focal perturbation will disrupt the entire subnetwork sustaining a given function. Thus, in contrast to functional neuroimaging, DES represents a unique opportunity to identify with great accuracy and reproducibility, in vivo in humans, the structures that are actually indispensable to the function, by inducing a transient virtual lesion based on the inhibition of a subcircuit lasting a few seconds. Currently, this is the sole technique that is able to directly investigate the functional role of white matter tracts in humans. Thus, combining transient disturbances elicited by DES with the anatomical data provided by pre- and postoperative MRI enables to achieve reliable anatomo-functional correlations, supporting a network organization of the brain, and leading to the reappraisal of models of language representation. Finally, combining serial peri-operative functional neuroimaging and online intraoperative DES allows the study of mechanisms underlying neuroplasticity. This chapter critically reviews the basic principles of DES, its advantages and limitations, and what DES can reveal about the neural foundations of language, that is, the large-scale distribution of language areas in the brain, their connectivity, and their ability to reorganize.

scholarly journals The Microbiota–Gut–Brain Axis and Alzheimer Disease. From Dysbiosis to Neurodegeneration: Focus on the Central Nervous System Glial Cells

2021 ◽  
Vol 10 (11) ◽  
pp. 2358
Author(s):  
Maria Grazia Giovannini ◽  
Daniele Lana ◽  
Chiara Traini ◽  
Maria Giuliana Vannucchi
Keyword(s):  
Alzheimer Disease ◽  
Glial Cells ◽  
Cell Types ◽  
The Past ◽  
The Central Nervous System ◽  
Diseased State ◽  
The Brain ◽  
Alzheimer Disease Pathogenesis ◽  
Brain Homeostasis

The microbiota–gut system can be thought of as a single unit that interacts with the brain via the “two-way” microbiota–gut–brain axis. Through this axis, a constant interplay mediated by the several products originating from the microbiota guarantees the physiological development and shaping of the gut and the brain. In the present review will be described the modalities through which the microbiota and gut control each other, and the main microbiota products conditioning both local and brain homeostasis. Much evidence has accumulated over the past decade in favor of a significant association between dysbiosis, neuroinflammation and neurodegeneration. Presently, the pathogenetic mechanisms triggered by molecules produced by the altered microbiota, also responsible for the onset and evolution of Alzheimer disease, will be described. Our attention will be focused on the role of astrocytes and microglia. Numerous studies have progressively demonstrated how these glial cells are important to ensure an adequate environment for neuronal activity in healthy conditions. Furthermore, it is becoming evident how both cell types can mediate the onset of neuroinflammation and lead to neurodegeneration when subjected to pathological stimuli. Based on this information, the role of the major microbiota products in shifting the activation profiles of astrocytes and microglia from a healthy to a diseased state will be discussed, focusing on Alzheimer disease pathogenesis.

scholarly journals Neuron–Glia Interactions in Tuberous Sclerosis Complex Affect the Synaptic Balance in 2D and Organoid Cultures

Cells ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 134
Author(s):  
Stephanie Dooves ◽  
Arianne J. H. van Velthoven ◽  
Linda G. Suciati ◽  
Vivi M. Heine
Keyword(s):  
Tuberous Sclerosis ◽  
Glial Cells ◽  
Tuberous Sclerosis Complex ◽  
Neuronal Development ◽  
Transmembrane Proteins ◽  
Significant Burden ◽  
Epidermal Growth ◽  
And Control ◽  
Egf Signaling ◽  
The Brain

Tuberous sclerosis complex (TSC) is a genetic disease affecting the brain. Neurological symptoms like epilepsy and neurodevelopmental issues cause a significant burden on patients. Both neurons and glial cells are affected by TSC mutations. Previous studies have shown changes in the excitation/inhibition balance (E/I balance) in TSC. Astrocytes are known to be important for neuronal development, and astrocytic dysfunction can cause changes in the E/I balance. We hypothesized that astrocytes affect the synaptic balance in TSC. TSC patient-derived stem cells were differentiated into astrocytes, which showed increased proliferation compared to control astrocytes. RNA sequencing revealed changes in gene expression, which were related to epidermal growth factor (EGF) signaling and enriched for genes that coded for secreted or transmembrane proteins. Control neurons were cultured in astrocyte-conditioned medium (ACM) of TSC and control astrocytes. After culture in TSC ACM, neurons showed an altered synaptic balance, with an increase in the percentage of VGAT+ synapses. These findings were confirmed in organoids, presenting a spontaneous 3D organization of neurons and glial cells. To conclude, this study shows that TSC astrocytes are affected and secrete factors that alter the synaptic balance. As an altered E/I balance may underlie many of the neurological TSC symptoms, astrocytes may provide new therapeutic targets.

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