Functional Evidence for Neurone Fields Representing the Individual Arms Within the Central Nervous System of Octopus

1959 ◽  
Vol 36 (3) ◽  
pp. 501-511
Author(s):  
M. J. WELLS
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Test Object ◽  
The Other ◽  
Optic Nerves ◽  
The Central Nervous System ◽  
The Individual ◽  
Tactile System

1. Octopuses blinded by section of the optic nerves were trained by means of 5-10 V. a.c. shocks to reject objects that they would otherwise take. 2. With trials at 3, 5, or 20 min. intervals, in which the test object was always presented to the same arm, animals learned within four or five trials, thereafter rejecting the test object whenever it was presented. 3. When, after a succession of such negative responses, the object was presented to another arm on the other side of the octopus, the result depended upon the rate of training before the change. Thus the object was taken in the trial immediately following the arm change in nineteen out of twenty-six sets of tests with trials at 3 or 5 min. intervals, but in only two out of twelve sets with trials at 20 min. intervals; further experiments in which changes were made between arms on the same side produced similar results. 4. These results are interpreted as showing that changes occurring as a result of experience directly affecting one arm take a period of several hours to spread and become effective in determining the reactions of the rest. This in turn implies the existence of functionally independent neurone fields representing the individual arms, and is discussed in relation to what is already known about the organization of the tactile system of the octopus.

scholarly journals XXVII.—On the Restoration of Co-ordinated Movements after Nerve Section

1900 ◽  
Vol 39 (3) ◽  
pp. 685-702 ◽  
Author(s):  
Robert Kennedy
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Point Of View ◽  
The Other ◽  
Nerve Fibres ◽  
Spinal Root ◽  
A Cell ◽  
The Central Nervous System ◽  
The One ◽  
The Individual

From the point of view of its function, a nerve fibre is a conductor of nervous impulses, and as such is the path of communication between two structures, the one situated in the central nervous system, and the other in the periphery. In the mixed nerve, such as the sciatic, the nerve fibres are distinguished as afferent or as efferent, according as they conduct impulses originating at the periphery, and received by a cell in the central nervous system, or vice versâ. It has long since been shown that nerve fibres are capable of conducting impulses in either direction, but normally, from their anatomical connections, the individual nerve fibres are conductors for impulses only in the one or in the other direction. This is proved by the Wallerian method of investigation, as on severance of the posterior spinal root distal to the ganglion only certain fibres degenerate and the conductivity of the nerve only for afferent impulses is lost, while the severance of the anterior root is followed by the degeneration of the remainder with loss of functions depending on efferent impulses.

The influence of lithium on the competence of the ectoderm in Ambystoma mexicanum

Development ◽  
1964 ◽  
Vol 12 (2) ◽  
pp. 317-331
Author(s):  
D. O. E. Gebhardt ◽  
P. D. Nieuwkoop
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Ambystoma Mexicanum ◽  
The Other ◽  
Direct Influence ◽  
Amphibian Embryos ◽  
The Central Nervous System ◽  
The Subject ◽  
Morphogenetic Potential ◽  
Made In

The influence of lithium on the amphibian egg has been the subject of a number of investigations. From the work of Lehmann (1937), Töndury (1938), and Pasteels (1945) it is known that exposure of amphibian embryos to lithium results in a progressive cranio-caudal reduction of the central nervous system and a simultaneous conversion of the presumptive notochord into somites. Whereas these experiments were made with whole embryos, attempts have been made in recent years to localize the lithium effect by transplanting or explanting specific parts of the embryo. Gallera (1949), for instance, concluded from his experiments with transplants containing lithium treated presumptive chorda mesoderm, that lithium had reduced the ‘morphogenetic potential’ of this inductor. Lombard (1952), on the other hand, claimed that the susceptibility of amphibian eggs towards lithium was the result of the ion's direct influence on the ectoderm rather than on the presumptive archenteron roof.

The Co-Ordination of Insect Movements

1957 ◽  
Vol 34 (3) ◽  
pp. 306-333
Author(s):  
G. M. HUGHES
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
The Body ◽  
The Other ◽  
Limb Amputation ◽  
Normal Movement ◽  
Thoracic Ganglia ◽  
Blatta Orientalis ◽  
The Central Nervous System ◽  
Leg Movements

I. The effects of limb amputation and the cutting of commissures on the movements of the cockroach Blatta orientalis have been investigated with the aid of cinematography. Detailed analyses of changes in posture and rhythm of leg movements are given. 2. It is shown that quite marked changes occur following the amputation of a single leg or the cutting of a single commissure between the thoracic ganglia. 3. Changes following the amputation of a single leg are immediate and are such that the support normally provided by the missing leg is taken over by the two remaining legs on that side. Compensatory movements are also found in the contralateral legs. 4. When two legs of opposite sides are amputated it has been confirmed that the diagonal sequence tends to be adopted, but this is not invariably true. Besides alterations in the rhythm which this may involve, there are again adaptive modifications in the movements of the limbs with respect to the body. 5. When both comrnissures between the meso- and metathoracic ganglia are cut, the hind pair of legs fall out of rhythm with the other four legs. The observations on the effects of cutting commissures stress the importance of intersegmental pathways in co-ordination. 6. It is shown that all modifications following the amputation of legs may be related to the altered mechanical conditions. Some of the important factors involved in normal co-ordination are discussed, and it is suggested that the altered movements would be produced by the operation of these factors under the new conditions. It is concluded that the sensory inflow to the central nervous system is of major importance in the co-ordination of normal movement.

On the incubation period in neurolues

1927 ◽  
Vol 23 (10) ◽  
pp. 1046-1050
Author(s):  
E. V. Sukhova
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Incubation Period ◽  
The Other ◽  
Other Hand ◽  
General Number ◽  
The Central Nervous System

Speaking about syphilis lesions of the central nervous system, it is impossible not to note that these lesions are among the most severe diseases of the latter. But, on the other hand, their severity is redeemed to some extent by the specific means of combating them which we have in our hands. In this case, the fight against neurolues is reduced not so much to its treatment as to its prevention. Hence the interest with which the question of the influence of various conditions on the occurrence of syphilitic lesions of the central nervous system has recently begun to be comprehensively discussed and the exact causes which, from the general number of syphilitics, distinguish the group subsequently condemned to neurolues have been sought to be elucidated.

scholarly journals About the connections of the cerebellum with the rest of the central nervous system

2020 ◽  
Vol V (4) ◽  
pp. 16-46
Author(s):  
F. K. Telyatnik
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
The Other ◽  
Valuable Data ◽  
The Central Nervous System

Now I turn to a brief summary of the content of some of the works specially devoted to the study of the cerebellar connections. I am not trying to collect all the literature related to this issue, but will confine myself only to the latest works produced with the help of the method most commonly used at the present time for solving questions about conducting paths, namely the method of rebirth. It must be said that a great service in this relationship was also rendered by the method of development, with the help of which a lot of valuable data were obtained, especially Bekhterev. But I will not dwell on them, since all the data obtained in the works of this author are set forth in the "Conducting Ways" and are already given above. As for the newest work performed according to the method of rebirth, all of them were carried out in such a way that one or another part of the cerebellum was damaged in the animal, or one or the other of its legs, and those regenerations were observed, which followed this damage. My works were produced in the same way, and therefore it is very easy to compare them with the works of other authors. This comparison is also favored by the fact that I produced the coloring of the preparations according to the Marchi method, which was also used by most of the researchers cited below.

scholarly journals The Relationships between Cholesterol and Suicide: An Update

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Domenico De Berardis ◽  
Stefano Marini ◽  
Monica Piersanti ◽  
Marilde Cavuto ◽  
Giampaolo Perna ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Cell Membrane ◽  
The Other ◽  
Core Component ◽  
Cell Membrane Stability ◽  
Cholesterol Levels ◽  
The Central Nervous System ◽  
Larger Sample

Cholesterol is a core component of the central nervous system, essential for the cell membrane stability and the correct functioning of neurotransmission. It has been observed that cholesterol may be somewhat associated with suicidal behaviours. Therefore, the aim of this paper was to elucidate current facts and views about the role of cholesterol levels in mood disorders. The majority of the studies reviewed in the present paper suggest an interesting relationship between cholesterol (especially lower levels) and suicidality. On the other hand, particularly during the last years, relationships between serum cholesterol and suicidality were doubted on the basis of some recent studies that have not found any correlation. However, the debate on relationships between cholesterol and suicide is open and longitudinal studies on a larger sample of patients are needed to further clarify this important issue.

Investigation into Intellectual Changes Following Prefrontal Leucotomy

1949 ◽  
Vol 95 (401) ◽  
pp. 826-841 ◽  
Author(s):  
R. K. Freudenberg ◽  
J. P. S. Robertson
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Structural Damage ◽  
Shock Treatment ◽  
Cognitive Changes ◽  
Normal Functions ◽  
Psychophysiological Functions ◽  
The Central Nervous System ◽  
The Individual ◽  
Interpretation Of Change

This investigation is not concerned with the clinical indications or results of prefrontal leucotomy, but attempts to re-examine changes following the operation, especially in regard to the impairment of some of the manifestations of the highest integrative psychophysiological functions of the central nervous system that may bring about such alterations. Amongst these we were primarily interested in cognitive changes, but the interpretation of apparent cognitive changes led to the consideration of orectic alterations as well. Such changes have so far been impossible to localize exactly, but are considered to be partly related to the phylogenetically more recent parts of the cerebral cortex. Masserman (1946) compared the mechanism of shock treatment and leucotomy with the effects of alcohol and states that “its main actions are those of a cortical depressant,” as manifested by impairment of finer perceptions and discriminations and a “constriction of the integrative field.” He believes that shock therapies and leucotomy partly produce their results by temporary or permanent decorticating effects, “rendering the individual no longer capable of fine spun fantasies or elaborate delusions.” These decorticating effects can be assumed to be reflected in cognitive, conative and emotional alterations following the operation. The interpretation of change following leucotomy presents many difficulties, one of them being that only dysfunction can be related to structural damage of the frontal lobe and not function. Another is that psychotics or severe neurotics operated upon usually do not have a sufficiently intact pre-operative personality to draw conclusions about the normal functions.

scholarly journals Metabolism of acetylcholine in the nervous system of Aplysia californica. I. Source of choline and its uptake by intact nervous tissue.

1975 ◽  
Vol 65 (3) ◽  
pp. 255-273 ◽  
Author(s):  
J H Schwartz ◽  
M L Eisenstadt ◽  
H Cedar
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Nervous Tissue ◽  
Aplysia Californica ◽  
The Other ◽  
Michaelis Constant ◽  
High Affinity ◽  
The Central Nervous System

Although acetylcholine is a major neurotransmitter in Aplysia, labeling studies with methionine and serine showed that little choline was synthesized by nervous tissue and indicated that the choline required for the synthesis of acetylcholine must be derived exogenously. Aanglia in the central nervous system (abdominal, cerebral, and pleuropedals) all took up about 0.5 nmol of choline per hour at 9 muM, the concentration of choline we found in hemolymph. This rate was more than two orders of magnitude greater than that of synthesis from the labeled precursors. Ganglia accumulated choline by a process which has two kinetic components, one with a Michaelis constant between 2-8 muM. The other component was not saturated at 420 muM. Presumably the process with the high affinity functions to supply choline for synthesis of transmitter, since the efficiency of conversion to acetylcholine was maximal in the range of external concentrations found in hemolymph.

Cerebral hemangioma with glial neoplasia (angioglioma?)

1982 ◽  
Vol 56 (3) ◽  
pp. 430-434 ◽  
Author(s):  
Edwin G. Fischer ◽  
Ana Sotrel ◽  
Keasley Welch
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
The Other ◽  
Content Type ◽  
Growth Reference ◽  
Biological Potential ◽  
Cavernous Hemangiomas ◽  
The Central Nervous System ◽  
Mass Lesions ◽  
Fine Print

✓ Two patients are reported who had intracerebral mass lesions composed of hemangioma and glial neoplasm. After excision, one recurred as an oligodendroglioma, and the remnant of the other remained static over a 5-year period. These lesions may represent a subgroup of cerebral hemangiomas that have the biological potential for future glial neoplastic growth. Reference is made to experimental work with polyoma virus which can induce cavernous hemangiomas in the central nervous system in mice, and which is a papovavirus. Other papovaviruses can induce ependymomas in hamsters.

scholarly journals The Production of Rabbits free from Lesions Associated with Encephalitozoon Cuniculi

1968 ◽  
Vol 2 (2) ◽  
pp. 143-146 ◽  
Author(s):  
J. Mcc Howell ◽  
N. Edington
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Experimental Results ◽  
The Other ◽  
Post Mortem ◽  
Encephalitozoon Cuniculi ◽  
Post Mortem Examination ◽  
The Central Nervous System

Lesions produced by Encephalitozoon cuniculi are common in the central nervous system of laboratory rabbits, and may affect experimental results. Post-mortem examination often does disclosed that three manifested typical lesions, while the other seven did not. Of the fourteen young born to the three does in which lesions were discovered, four (29 per cent) were free from obvious evidence of the disease. Of the fifty young born to the seven lesion-free does, forty-seven (94 per cent) were also free from such lesions.

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