scholarly journals Lipids of the Nervous System of the Squid Loligo Pealii

1951 ◽  
Vol 28 (1) ◽  
pp. 116-124
Author(s):  
J. D. McCOLL ◽  
R. J. ROSSITER
Keyword(s):  
Nervous System ◽  
White Matter ◽  
Total Cholesterol ◽  
Phosphatidyl Choline ◽  
Grey Matter ◽  
Relative Concentration ◽  
Mammalian Brain ◽  
Giant Fibre ◽  
Myelinated Fibres ◽  
The Brain

1. The concentration of total phospholipin, free and total cholesterol, cerebroside (glycosphingoside), monoaminophospholipin (phosphoglyceride) and lecithin (phosphatidyl choline) was determined in the central ganglia, pallial nerve, whole giant fibre of the stellar nerve, and axoplasm of the giant fibre of the squid, Loligo pealii. From these figures was calculated the concentration of ester cholesterol, sphingomyelin (phosphosphingoside) and kephalin. 2. The concentration of total phospholipin in the central ganglia was of the same order as that found in mammalian brain, but the concentration of cholesterol and sphingomyelin was less. 3. The concentration of lipids in the pallial nerve was less than that in the central ganglia. The concentration of lecithin exceeded that of kephalin, while sphingomyelin accounted for higher percentage for phospholipin than in the central ganglia. 4. The concentration of lipids in the whole giant fibre of the stellar nerve, less than that in either the central ganglia or in the pallial nerve, was greater than that in the axoplasm. 5. The results are consistent with the view that the axon of the giant fibre of the stellar nerve is surrounded by a thin lipid-containing sheath. 6. Neither cerebroside nor ester cholesterol was found in the nervous system of the squid. 7. With the exception of cerebroside, the relative concentration of lipids in the central ganglia and in the axoplasm of the giant fibre resembled that in parts of the nervous system of man that contain relatively few myelinated fibres, i.e. the grey matter of the brain of the adult or either the grey matter or the white matter of the brain of the newborn infant.

XVI. Note on the minute structure of the grey matter of the convolutions of the brain of man, the sheep, cat, and dog

1863 ◽  
Vol 12 ◽  
pp. 671-673
Keyword(s):  
Grey Matter ◽  
Nerve Cells ◽  
Mammalian Brain ◽  
New Process ◽  
The Brain ◽  
Thick Fibre

By a new process of investigation, I have succeeded in demonstrating the connexion between the nerve-cells and fibres in the grey matter of the convolutions and in other parts of the mammalian brain, and have followed individual fibres for a much greater distance than can be effected in sections prepared by other processes of investigation which I have tried. In many instances one thick fibre is continuous with one or other extremity of the “cell,” while from its opposite portion from three to six or eight thinner fibres diverge in a direction onwards and outwards. This arrangement is particularly distinct in the grey matter of the sheep’s brain.

Spinal cord grey matter lesions in multiple sclerosis detected by post-mortem high field MR imaging

2008 ◽  
Vol 15 (2) ◽  
pp. 180-188 ◽  
Author(s):  
CP Gilmore ◽  
JJG Geurts ◽  
N Evangelou ◽  
JCJ Bot ◽  
RA van Schijndel ◽  
...  
Keyword(s):  
Spinal Cord ◽  
White Matter ◽  
Mr Imaging ◽  
High Field ◽  
Grey Matter ◽  
Great Majority ◽  
Proton Density ◽  
Post Mortem ◽  
Mr Images ◽  
The Brain

Background Post-mortem studies demonstrate extensive grey matter demyelination in MS, both in the brain and in the spinal cord. However the clinical significance of these plaques is unclear, largely because they are grossly underestimated by MR imaging at conventional field strengths. Indeed post-mortem MR studies suggest the great majority of lesions in the cerebral cortex go undetected, even when performed at high field. Similar studies have not been performed using post-mortem spinal cord material. Aim To assess the sensitivity of high field post-mortem MRI for detecting grey matter lesions in the spinal cord in MS. Methods Autopsy material was obtained from 11 MS cases and 2 controls. Proton Density-weighted images of this formalin-fixed material were acquired at 4.7Tesla before the tissue was sectioned and stained for Myelin Basic Protein. Both the tissue sections and the MR images were scored for grey matter and white matter plaques, with the readers of the MR images being blinded to the histopathology results. Results Our results indicate that post-mortem imaging at 4.7Tesla is highly sensitive for cord lesions, detecting 87% of white matter lesions and 73% of grey matter lesions. The MR changes were highly specific for demyelination, with all lesions scored on MRI corresponding to areas of demyelination. Conclusion Our work suggests that spinal cord grey matter lesions may be detected on MRI more readily than GM lesions in the brain, making the cord a promising site to study the functional consequences of grey matter demyelination in MS.

scholarly journals A higher proportion of ermin-immunopositive oligodendrocytes in areas of remyelination

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0256155
Author(s):  
Intakhar Ahmad ◽  
Stig Wergeland ◽  
Eystein Oveland ◽  
Lars Bø
Keyword(s):  
Multiple Sclerosis ◽  
White Matter ◽  
Corpus Callosum ◽  
Mouse Model ◽  
Grey Matter ◽  
Early Stage ◽  
Relative Proportion ◽  
Normal Appearing White Matter ◽  
The Brain

Incomplete remyelination is frequent in multiple sclerosis (MS)-lesions, but there is no established marker for recent remyelination. We investigated the role of the oligodendrocyte/myelin protein ermin in de- and remyelination in the cuprizone (CPZ) mouse model, and in MS. The density of ermin+ oligodendrocytes in the brain was significantly decreased after one week of CPZ exposure (p < 0.02). The relative proportion of ermin+ cells compared to cells positive for the late-stage oligodendrocyte marker Nogo-A increased at the onset of remyelination in the corpus callosum (p < 0.02). The density of ermin-positive cells increased in the corpus callosum during the CPZ-phase of extensive remyelination (p < 0.0001). In MS, the density of ermin+ cells was higher in remyelinated lesion areas compared to non-remyelinated areas both in white- (p < 0.0001) and grey matter (p < 0.0001) and compared to normal-appearing white matter (p < 0.001). Ermin immunopositive cells in MS-lesions were not immunopositive for the early-stage oligodendrocyte markers O4 and O1, but a subpopulation was immunopositive for Nogo-A. The data suggest a relatively higher proportion of ermin immunopositivity in oligodendrocytes compared to Nogo-A indicates recent or ongoing remyelination.

scholarly journals Lissencephaly and cerebellar hypoplasia in a goat

2013 ◽  
Vol 43 (10) ◽  
pp. 1858-1861 ◽  
Author(s):  
José Rômulo Soares dos Santos ◽  
Antônio Flavio Medeiros Dantas ◽  
Clarice Ricardo Macedo Pessoa ◽  
Tatiane Rodrigues Silva ◽  
Sara Vilar Dantas Simões ◽  
...  
Keyword(s):  
White Matter ◽  
Grey Matter ◽  
Cerebellar Hypoplasia ◽  
Infectious Origin ◽  
Gross Lesions ◽  
The Brain

A case of lissencephaly and cerebellar hypoplasia was observed in a 30-day-old goat. The goat presented with sternal recumbence, absence of a menace response, intention tremors, ataxia, and nystagmus. The goat was euthanized and necropsied after having been hospitalised for eleven days. At necropsy, the surface of the brain was found to be smooth, the cerebral sulci and gyri were absent, and the cerebellum was reduced in size. Histologically, the grey matter and white matter were thicker and thinner than normal in cortices, respectively. The neurons were randomly arranged in the grey matter. In the cerebellum, the layers were disorganised, and cells were heterotopics. The histologic and gross lesions observed in this animal are characteristic of lissencephaly associated with cerebellar hypoplasia. The presence of a single goat affected suggests that the malformation was not of infectious origin and because lissencephaly is a malformation not previously described in goats, it is unlikely this case was inherited.

scholarly journals Determining the Bioenergetic Capacity for Fatty Acid Oxidation in the Mammalian Nervous System

2020 ◽  
Vol 40 (10) ◽  
Author(s):  
Cory J. White ◽  
Jieun Lee ◽  
Joseph Choi ◽  
Tiffany Chu ◽  
Susanna Scafidi ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Nervous System ◽  
Fatty Acid ◽  
Conditional Knockout ◽  
Mammalian Brain ◽  
Metabolic State ◽  
Peripheral Tissues ◽  
Mitochondrial Fatty Acid ◽  
The Brain ◽  
Long Chain

ABSTRACT The metabolic state of the brain can greatly impact neurologic function. Evidence of this includes the therapeutic benefit of a ketogenic diet in neurologic diseases, including epilepsy. However, brain lipid bioenergetics remain largely uncharacterized. The existence, capacity, and relevance of mitochondrial fatty acid β-oxidation (FAO) in the brain are highly controversial, with few genetic tools available to evaluate the question. We have provided evidence for the capacity of brain FAO using a pan-brain-specific conditional knockout (KO) mouse incapable of FAO due to the loss of carnitine palmitoyltransferase 2, the product of an obligate gene for FAO (CPT2B−/−). Loss of central nervous system (CNS) FAO did not result in gross neuroanatomical changes or systemic differences in metabolism. Loss of CPT2 in the brain did not result in robustly impaired behavior. We demonstrate by unbiased and targeted metabolomics that the mammalian brain oxidizes a substantial quantity of long-chain fatty acids in vitro and in vivo. Loss of CNS FAO results in robust accumulation of long-chain acylcarnitines in the brain, suggesting that the mammalian brain mobilizes fatty acids for their oxidation, irrespective of diet or metabolic state. Together, these data demonstrate that the mammalian brain oxidizes fatty acids under normal circumstances with little influence from or on peripheral tissues.

scholarly journals The giant myelinated nerve fibres of the prawn

1942 ◽  
Vol 231 (582) ◽  
pp. 293-311 ◽  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Myelin Sheath ◽  
Single Cells ◽  
Myelinated Fibre ◽  
Complete Fusion ◽  
Giant Fibre ◽  
The Central Nervous System ◽  
Giant Fibres ◽  
Myelinated Fibres

Evidence is given that the median and lateral longitudinal giant myelinated fibres in the central nervous system of the prawn Leander serratus are syncitial structures, each formed by the fusion of the processes of many segmental nerve cells. Septa are found at intervals in the axoplasm of the median fibres, but they never completely transect it. They are probably relics of a condition similar to that in the earthworm where the giant fibre running the length of the cord is formed of a chain of segmental syncitial axons each divided from its neighbour by a complete septum which presumably functions as a synapse. The motor giant fibres, which are segmental and pass out of the central nervous system to the muscles, are the processes of single cells: the axoplasms of the two fibres of the pair in each segment undergo complete fusion with each other and then redivision before leaving the central nervous system. These motor giant fibres are non-myelinated within the central nervous system, although as great in diameter as other heavily myelinated fibres. They are myelinated outside the central nervous system. In the prawn therefore myelin sheath thickness is not an invariable function of axon diameter. The lateral giant-fibre synapses show complete axoplasmic discontinuity and their structure does not support Johnson’s creation of a new category of synaptic relations. Two types of synapses between fibres are described. In the first, found in the lateral giant-fibre chain, two myelinated fibres lie closely side by side for a considerable distance, but their neuroplasms are separated by a myelin layer except over an extent of less than 10 μ . In the second type, found at the point of contact of both the median and lateral fibres with the motor fibres, a myelinated fibre has synaptic connexions with a large non-myelinated fibre through many fine axonic processes which pass out through a small gap in the myelin sheath.

Fast Analytical Sensing Technology: Microelectrode-Based Recordings of Tonic and Phasic Neurotransmitter Signalling in the Mammalian Brain

2018 ◽  
pp. 500-510
Author(s):  
Michelle L. Humeiden ◽  
Jorge E. Quintero ◽  
John T. Slevin ◽  
Greg A. Gerhardt
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Clinical Applications ◽  
Mammalian Brain ◽  
Excitatory Neurotransmitter ◽  
Ideal Candidate ◽  
Ca1 Region ◽  
Sensing Technology ◽  
The Central Nervous System ◽  
The Brain

Communication in the nervous system is predominately chemical. However, understanding of neurotransmitter signalling in normal and diseased states remains lacking. Electrochemically based biosensors can detect chemical messengers on a near-real timescale, allowing exploration of neurotransmitter systems to bring into focus the functioning elements of this critical means of communication. Glutamate, the predominant excitatory neurotransmitter of the central nervous system, is an ideal candidate for measurement with biosensors. With biosensors, it has been found that spontaneous glutamate signals in the dentate gyrus are enhanced in kindled animals. Meanwhile, in a model of epilepsy, the utility of detecting and the dynamism of glutamate signalling become apparent as tonic glutamate levels and rapid, spontaneous phasic glutamate signals show a correlation with seizure activity in the CA1 region of rodents. The ability of these biosensors to detect neurotransmitters in the brain is promising for clinical applications to monitor and, eventually, treat epilepsy.

Real Brains and Model Brains

1989 ◽  
Author(s):  
Roger Penrose ◽  
Martin Gardner
Keyword(s):  
Cerebral Cortex ◽  
White Matter ◽  
Grey Matter ◽  
Cerebral Hemispheres ◽  
Human Beings ◽  
Surface Layers ◽  
Alan Turing ◽  
The World ◽  
Left And Right ◽  
The Brain

Inside our heads is a magnificent structure that controls our actions and somehow evokes an awareness of the world around. Yet, as Alan Turing once put it, it resembles nothing so much as a bowl of cold porridge! It is hard to see how an object of such unpromising appearance can achieve the miracles that we know it to be capable of. Closer examination, however, begins to reveal the brain as having a much more intricate structure and sophisticated organization. The large convoluted (and most porridge-like) portion on top is referred to as the cerebrum. It is divided cleanly down the middle into left and right cerebral hemispheres, and considerably less cleanly front and back into the frontal lobe and three other lobes: the parietal, temporal and occipital. Further down, and at the back lies a rather smaller, somewhat spherical portion of the brain - perhaps resembling two balls of wool - the cerebellum. Deep inside, and somewhat hidden under the cerebrum, lie a number of curious and complicated-looking different structures: the pons and medulla (including the reticular formation, a region that will concern us later) which constitute the brain-stem, the thalamus, hypothalamus, hippocampus, corpus callosum, and many other strange and oddly named constructions. The part that human beings feel that they should be proudest of is the cerebrum - for that is not only the largest part of the human brain, but it is also larger, in its proportion of the brain as a whole, in man than in other animals. (The cerebellum is also larger in man than in most other animals.) The cerebrum and cerebellum have comparatively thin outer surface layers of grey matter and larger inner regions of white matter. These regions of grey matter are referred to as, respectively, the cerebral cortex and the cerebellar cortex. The grey matter is where various kinds of computational task appear to be performed, while the white matter consists of long nerve fibres carrying signals from one part of the brain to another. Various parts of the cerebral cortex are associated with very specific functions.

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