The effect of aging on lysosomal permeability in nerve cells of the central nervous system. An enzyme histochemical study in rat

Histochemie ◽  
1972 ◽  
Vol 30 (4) ◽  
pp. 315-324 ◽  
Author(s):  
Ulf Brunk ◽  
Arne Brun
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Histochemical Study ◽  
Nerve Cells ◽  
The Central Nervous System

The Giant Nerve-Fibres in the Central Nervous System of Myxicola (Polychaeta, Sabellidae)

1948 ◽  
Vol s3-89 (5) ◽  
pp. 1-45
Author(s):  
J.A. C. NICOL
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Nerve Cord ◽  
Size Structure ◽  
Nerve Cells ◽  
The Body ◽  
Usual Sense ◽  
Fibrous Sheath ◽  
Giant Fibre ◽  
The Central Nervous System

1. A description is given of the main features of the central nervous system of Myxicola infundibulum Rénier. 2. The nerve-cord is double in the first four thoracic segments and single posteriorly. It shows segmental swellings but is not ganglionated in the usual sense in that nerve-cell accumulations are not related directly to such swellings of the cord. 3. A very large axon lies within the dorsal portion of the nerve-cord and extends from the supra-oesophageal ganglia to the posterior end of the animal. It is small in the head ganglia where it passes transversely across the mid-line, increases in diameter in the oesophageal connectives, and expands to very large size, up to 1 mm., in the posterior thorax and anterior abdomen, and gradually tapers off to about 100µ in the posterior body. It shows segmental swellings corresponding to those of the nerve-cord in each segment. It occupies about 27 per cent, of the volume of the central nervous system and 0.3 per cent, of the volume of the animal. The diameter of the fibre increases during contraction of the worm. 4. The giant fibre is a continuous structure throughout its length, without internal dividing membranes or septa. Usually a branch of the giant fibre lies in each half of the nerve-cord in the anterior thoracic segments and these several branches are continuous with one another longitudinally and transversely. 5. The giant fibre is connected with nerve-cells along its entire course; it arises from a pair of cells in the supra-oesophageal ganglia, and receives the processes of many nerve-cells in each segment. There is no difference between the nerve-cells of the giant fibre and the other nerve-cells of the cord. 6. A distinct fibrous sheath invests the giant fibre. A slight concentration of lipoid can be revealed in this sheath by the use of Sudan black. 7. About eight peripheral branches arise from the giant fibre in each segment. They have a complex course in the nerve-cord where they anastomose with one another and receive the processes of nerve-cells. Peripherally, they are distributed to the longitudinal musculature. 8. Specimens surviving 16 days following section of the nerve-cord in the thorax have shown that the giant fibre does not degenerate in front of or behind a cut, thus confirming that it is a multicellular structure connected to nerve-cells in the thorax and abdomen. 9. It is concluded that the giant fibre of M. infundibulum is a large syncytial structure, extending throughout the entire central nervous system and the body-wall of the animal. 10. The giant fibre system of M. aesthetica resembles that of M. infundibulum. 11. Some implications of the possession of such a giant axon are discussed. It is suggested that its size, structure, and simplicity lead to rapid conduction and thus effect a considerable saving of reaction time, of considerable value to the species when considered in the light of the quick contraction which it mediates. The adoption of a sedentary mode of existence has permitted this portion of the central nervous system to become developed at the expense of other elements concerned with errant habits.

scholarly journals Further Observations on Proprioceptors in Crustacea and a Hypothesis About Their Function

1958 ◽  
Vol 37 (2) ◽  
pp. 379-396 ◽  
Author(s):  
J. S. Alexandrowicz
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Connective Tissue ◽  
Sensory Neurons ◽  
Similar Pattern ◽  
Nerve Cells ◽  
The Central Nervous System

In the coxal region of Eupagurus bernardus the following receptor organs have been found: (1) a muscular receptor spanning the thoracico-coxal articulation, its innervation, in which several neurons take part, being arranged on a similar pattern as in Carcinus; (2) two innervated elastic strands running along the bundles of mm. levator and depressor basipoditis respectively and inserting into the tendons of these muscles; (3) a coxo-basipodite receptor consisting of connective tissue strand with numerous bipolar nerve cells ending on it. With the exception of the coxo-basipodite receptor, all sensory neurons of these organs have their cell bodies located in the central nervous system.It is suggested that these receptors convey impulses elicited by the movements of the legs and some hypotheses concerning the role of each of them are put forward.

scholarly journals The Role of Vitamin D in Neurodegeneration and Other Pathological Processes of the Central Nervous System

2021 ◽  
Author(s):  
Carl Nikolaus Homann
Keyword(s):  
Central Nervous System ◽  
Vitamin D ◽  
Nervous System ◽  
Human Body ◽  
Serum Levels ◽  
Nerve Cells ◽  
Pivotal Role ◽  
The Central Nervous System ◽  
Measured Response

The nervous system is the most complex organ in the human body, and it is the most essential. However nerve cells are particularly precious as, only like muscle cells, once formed, they do not replicate. This means that neural injuries cannot easily be replaced or repaired. Vitamin D seems to play a pivotal role in protecting these vulnerable and most important structures, but exactly how and to what extend is still subject to debate. Systematically reviewing the vast body of research on the influence of Vitamin D in various neuropathological processes, we found that Vitamin D particularly plays a mitigating role in the development of chronic neurodegeneration and the measured response to acutely acquired traumatic and non-traumatic nerve cells incidents. Adequate serum levels of Vitamin D before the initiation of these processes is increasingly viewed as being neuroprotective. However, comprehensive data on using it as a treatment during the ongoing process or after the injury to neurons is completed are much more ambiguous. A recommendation for testing and supplementation of insufficiencies seems to be well-founded.

scholarly journals FEATURES OF NEUROPLASTIC VARIABILITY OF PROJECTION NEURONS IN THE CONDITIONS OF EXPERIMENTAL DESTRUCTION OF VARIOUS STRUCTURES OF THE CENTRAL NERVOUS SYSTEM

2021 ◽  
Vol 2 (66) ◽  
pp. 4-8
Author(s):  
S. Badalyan
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Axonal Transport ◽  
Transport System ◽  
Nerve Cells ◽  
Projection Neurons ◽  
The Central Nervous System ◽  
Pathological Manifestation

The morphological manifestations of neuroplastic variability of projection neurons were studied under conditions of experimental destruction of various structures of the central nervous system in animals. Various forms of pathological manifestations of neuroplastic variability of “survivors” (after exposure to a damaging factor) marked through the axonal transport system of neurons are shown. Marked nerve cells of an unusual, bizarre shape, denoted by the term "ugly neurons", are proposed to be considered as one of the criteria for the pathological manifestation of neuroplastic variability of projection neurons.

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