Concluding remarks

The discussion has shown that plasticity in the nervous system is now a topic that is actively investigated by physiologists and psychologists. When I gave the Ferrier Lecture on the subject 25 years ago it was little understood and what was known was mostly about the peripheral nervous system. We now also have a considerable body of knowledge about plasticity in the central nervous system, even in mammals, which is welcome both for its importance in medicine and for our understanding of the fundamental problems of neuroscience. The brain depends upon different channels responding to different items of information, so the key to understanding it is to find out how the channels become connected. The conference has shown that, as in all developmental problems, heredity and environment both play their part. Every aspect of the brain is ‘doubly dependent’, on genetic influences from within and environmental ones from outside. The capacity to respond during development is presumably itself programmed in the genome. Keating showed how adaptive changes are needed in Xenopus to make the receptors and the nervous system keep pace with the changing pattern of behaviour.

Author(s):  
S.S. Spicer ◽  
B.A. Schulte

Generation of monoclonal antibodies (MAbs) against tissue antigens has yielded several (VC1.1, HNK- 1, L2, 4F4 and anti-leu 7) which recognize the unique sugar epitope, glucuronyl 3-sulfate (Glc A3- SO4). In the central nervous system, these MAbs have demonstrated Glc A3-SO4 at the surface of neurons in the cerebral cortex, the cerebellum, the retina and other widespread regions of the brain.Here we describe the distribution of Glc A3-SO4 in the peripheral nervous system as determined by immunostaining with a MAb (VC 1.1) developed against antigen in the cat visual cortex. Outside the central nervous system, immunoreactivity was observed only in peripheral terminals of selected sensory nerves conducting transduction signals for touch, hearing, balance and taste. On the glassy membrane of the sinus hair in murine nasal skin, just deep to the ringwurt, VC 1.1 delineated an intensely stained, plaque-like area (Fig. 1). This previously unrecognized structure of the nasal vibrissae presumably serves as a tactile end organ and to our knowledge is not demonstrable by means other than its selective immunopositivity with VC1.1 and its appearance as a densely fibrillar area in H&E stained sections.


1895 ◽  
Vol 41 (175) ◽  
pp. 622-635
Author(s):  
W. F. Robertson

There is at the present time great need of more complete and definite knowledge as to the pathology of the very marked structural changes that so commonly affect the pia-arachnoid in the insane. The subject is one of much importance to all of us as medical psychologists, for not only is the condition in question one of the most conspicuous lesions associated with mental disease, but it implicates a structure of primary importance in the economy of the central nervous system. It is by way of vessels that course through this membrane that nutriment is conveyed to the brain cortex, and the waste products resulting from metabolism in the cerebral tissues are mainly conveyed away in the fluid that circulates in its lymph spaces. Therefore it is evident that these morbid changes may very seriously interfere with the functions both of nutrition and excretion in the brain.


1953 ◽  
Vol 99 (417) ◽  
pp. 689-697 ◽  
Author(s):  
Noel Alder

Corpora amylacea (C.A.) or amyloid bodies found in the brain and the product of amyloid degeneration in other organs derive their name from the starch-like reaction which they give with iodine (Virchow); otherwise these substances have few points in common, and while amyloid disease has become fairly rare nowadays, the presence of C.A. constitutes one of the regular changes in senile and senescent brains. This is perhaps why it has attracted much less attention than amyloid degeneration. For instance in 18 out of 25 papers, containing detailed accounts of the histo-pathological pictures, I found no references to C.A., yet one could hardly assume that amyloid bodies were overlooked. Most text-books pay scanty attention to the subject, while Buzzard and Greenfield (1921) consider it of no pathological significance. Since, however, C.A. are encountered under a variety of conditions (not merely senility), in greatly varying amounts and at different sites in the central nervous system, it may be worth while to investigate their nature, origin and occurrence in the light of recent observation.


1927 ◽  
Vol 23 (4) ◽  
pp. 464-464
Author(s):  
V. I. Znamensky

According to V. I. Znamensky indicated for treatment in Matsesta: 1) diseases of the peripheral nervous system, -neuralgia, neuritis; 2) diseases of the central nervous system connected with disorders of the cardiovascular system, - hemiplegia and hemiparesis due to thrombosis and embolism; (treatment of acute forms of the mentioned diseases, it goes without saying, is contraindicated); 3) Luetic diseases,-vascular syphilis of the brain, lues cerebrospinalis, meningo-myelitis, tabes dorsalis incipiens and Luetic radiculitis (here; baths, giving increase of metabolism and excretions, make possible mercury treatment with impunity); 4) remnants of lethargic encephalitis.


1939 ◽  
Vol 85 (354) ◽  
pp. 119-125 ◽  
Author(s):  
R. E. Hemphill

On the subject of the correlation of neurological lesions with psycho-pathological phenomena, two eminent neuro-histologists, the Werthams, have recently written: “It must be pointed out that in proportion to the extraordinary complexity and differentiation of the finer functions mediated by the central nervous system, histological lesions are very gross. However we may conceive of the functional processes going on in the central nervous system—physiological, physico-chemical, metabolic, electrical, etc.—it should be obvious that only the grossest miscarriages and defects would become morphologically visible. Structural lesions are the effect of functional reactions that are not histologically demonstrable. Physico-chemical changes, metabolic processes, functional changes of blood-vessels, and similar biological phenomena that cannot be micro-histologically demonstrated, precede the anatomically visible lesions which occur only where the processes have attained a certain intensity. What we can demonstrate histologically in the nervous parenchyma is not by any means an adequate basis for the understanding of the quality, intensity or normality of nervous functions. In a patient who dies in the convulsions of tetanus, the anterior horn-cells may reveal nothing abnormal. Even the most minute and complete histological examination of the central nervous system in a case may fail to reveal any evidence of an existing profound disorder of brain function. There are cases of idiocy of the severest type in which no significant histological changes may be demonstrable in the brain.”


1882 ◽  
Vol 33 (216-219) ◽  
pp. 400-403

The author, after a preliminary sketch of the literature of the subject, and a description of his method of hardening and staining, proceeds to give an idea of the external aspect of the central nervous system in the Mormyridæ.


2020 ◽  
Vol V (3) ◽  
pp. 164-166
Author(s):  
A. E. Smirnov

The question of the regeneration of the nervous tissue in general and the elements of the central nervous system in particular was the subject of numerous and conscientious studies; but to this day this question is open, it is the arena of various, even directly opposite views. The author, on the basis of his numerous, which required a significant investment of time and labor, experiments and observations, decides the question in a positive sense regarding the participation of nervous elements in the regeneration of the central nervous system in mammals. The author, in a large, but complete essay, introduces the issue to the literature, sets out in detail the technique of performing experiments, points to the technique that he used in microscopic studies, gives several protocols of pathological and anatomical dissections of experimental animals and, finally, details of microscopic studies of the brain with an illustration of words with the corresponding drawings, gives conclusions from their observations, the presentation of which I will limit myself to this abstract.


1899 ◽  
Vol 64 (402-411) ◽  
pp. 176-179 ◽  

In this research the modern methods of investigating the course of tracts and their degeneration in the central nervous system have been used. The previous literature of the subject is scanty. Bumm first gave an account of the various tracts in the brain, and the histological side has been and is still being worked out by Brandis. Valuable information is given by Edinger in his ‘Vorlesungen,’ and quite recently the Marchi method has been used and the results obtained described by Wiener and Münzer, Wallenberg and Friedländer.


1882 ◽  
Vol 173 ◽  
pp. 927-959 ◽  

Marcusen has given a very good résumé of the zoological history of this family from the time of their first discovery by Hasselquist, a pupil of Linneus, up to the date of the publication of his paper by the St. Petersburg Academy, and as his treatise is easily accessible there is no occasion for my going into that part of the subject here. The external appearance of these Fishes gives no indication at all of anything extraordinary in the structure of the brain, and as the zoologist above referred to, did not pay much attention to anatomy, more than half a century elapsed before any steps were taken in that direction. One of the species at least was very well known to the ancient Egyptians, to whom it was a sacred animal, and its portrait is even now quite easily distinguishable on some of the monuments.


Author(s):  
Gladys Harrison

With the advent of the space age and the need to determine the requirements for a space cabin atmosphere, oxygen effects came into increased importance, even though these effects have been the subject of continuous research for many years. In fact, Priestly initiated oxygen research when in 1775 he published his results of isolating oxygen and described the effects of breathing it on himself and two mice, the only creatures to have had the “privilege” of breathing this “pure air”.Early studies had demonstrated the central nervous system effects at pressures above one atmosphere. Light microscopy revealed extensive damage to the lungs at one atmosphere. These changes which included perivascular and peribronchial edema, focal hemorrhage, rupture of the alveolar septa, and widespread edema, resulted in death of the animal in less than one week. The severity of the symptoms differed between species and was age dependent, with young animals being more resistant.


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