Memoirs: The Innervation of the Heart of Crustacea

1934 ◽  
Vol s2-76 (304) ◽  
pp. 511-548
Author(s):  
J. S. ALEXANDROWICZ

1. The three systems of nerves, viz. the local system, the regulator nerves, and the nerves of the arterial valves, which were previously described by the writer as innervating the heart of the Decapod Crustacea, have also been found in Squilla mantis. 2. The local system consists of not less than fourteen neurons. Their cells are situated in a nerve-trunk running alongside the dorsal surface of the heart, and, with the exception of the three anterior elements, lie at regular intervals each behind a pair of the ostial orifices. The cells give off the following processes: (a) the axons which form the chief part of the fibres in the ganglionic trunk and which after sending off many branches end on the muscle-fibres of the myocardium; (b) the dendrites--short arborescent branches arising both from cell-bodies and axons, and ending in the neighbourhood of the trunk on themuscle-fibres too; (c) short collaterals ending in fine networks of fibrils in the ganglionic trunk. 3. The system of regulator nerves connecting the local system with the central nervous system, in the Decapoda consisting of one pair of nerves, is represented in the Stomatopoda by three paired nerves which in our description have been termed Nervi cardiaci dorsales. For the designation of each of them the letters α,β, and γ have been used. Their course indicates that they originate in the large thoracic ganglionic mass. After passing on the dorsal side of the extensor muscles these nerves approach the heart from its dorsal side, and enter its ganglionic trunk in the region of the fourth body-segment. The nerve a is made up of one thick fibre only, the nerves β and γ contain one thick and several thinner fibres each. In the ganglionic trunk two sets of fibres given off by the dorsal nerves can be distinguished: one of them, termed System I, is made up of thicker fibres whose branches give synapses with the cells, collaterals, and dendrites of the local neurons; the other, called System II, consists of thinner fibres accompanying the long branches of the axons which pass to the muscles. 4. The system of nerves supplying the arterial valves is made up of (a) the anterior cardiac nerve running to the valve of the anterior aorta; and (b) the segmental nerves of the heart passing in each metamere to the valves of the paired arteries. There are, in all, fifteen pairs of these nerves. The last pair supplies the valves of the fifteenth pair of arteries and the valve of the posterior aorta. Each segmental nerve sends off anastomotic branches to the contralateral nerve, but does not show any connexions with the nerves of the neighbouring segments. In this respect these nerves in Squilla differ from those in the Decapods since in the latter they are all interconnected by anastomosing fibres. On the other hand, in Squilla as well as in Decapods the anterior cardiac nerve has no connexion with the segmental nerves of the heart. 5. With regard to the function of the nerve-elements enumerated above, the local system is to be considered as an autonomic apparatus which rules the beat of the heart, whereas the dorsal nerves convey the inhibitory and accelerator impulses from the central nervous system. The first of the dorsal nerves, α, has been found carrying the inhibitory impulses. The stimulation of the two following nerves, β and γ, quickens the beat of the heart, but this effect of the physiological experiment does not exclude the possibility that the nerves β and γ contain both inhibitory and accelerator fibres. The two sets of fibres in the ganglionic trunk which have been termed Systems I and II are probably concerned the former with the inhibitory and the latter with the accelerator action. The function of the nerves of the arterial valves probably consists in the maintaining of a tonic contraction of the muscles of the valves.

1971 ◽  
Vol 54 (2) ◽  
pp. 329-350
Author(s):  
T. MILLER ◽  
P. N. R. USHERWOOD

1. The heart of Periplaneta americana is segmentally innervated from the central nervous system by three types of neurone. Two of these types of neurones are neurosecretory; one type contains large granules, the other small granules. The segmental nerves are paired structures which join paired lateral cardiac nerve cords. Both types of neurosecretory neurone liberate their contents in the lateral cardiac nerve cords. The neurones with the small granules also synapse with the myocardium as well as with intrinsic cardiac neurones in the lateral cardiac nerve cords. The third type of neurone from the central nervous system is an ordinary efferent neurone and it synapses with the cardiac ganglion cells. 2. A heart chamber is associated with about six cardiac ganglion cells, three on either side. These send processes up and down the lateral cardiac nerve cord and make synaptic contact with the myocardium. 3. The myocardium is multiterminally and polyneuronally innervated, and electrical coupling between muscle fibres appears to be the rule. The fibres are spontaneously active and generate spike-like electrically excited responses. The timing of the electrically excited responses is influenced by the input from the cardiac ganglion cells which evoke a burst of synaptic potentials during diastole. 4. Control of the cockroach heart appears to be organized on three levels. The basic rhythm is myogenic. The timing of the contractions is influenced by inputs from the intrinsic cardiac ganglion cells possibly via a feedback mechanism involving the contractions of the heart muscle. Finally, the activities of the heart muscle and the cardiac ganglion cells are influenced by inputs from the central nervous system.


Author(s):  
J. S. Alexandrowicz

SummaryIn the heart of Marinogammarus marinus three systems of nerve elements have been found, viz. (1) a local system consisting of a ganglionic trunk situated on the dorsal surface of the heart and sending branches to the muscle fibres, (2) two paired nerves, termed the 1st and 2nd cardiac nerves, connecting the local system with the central nervous system, and (3) nerves supplying the muscles of the arterial valves. It is assumed that the local system rules the beat of the heart and that the cardiac nerves have a regulating function.Not directly connected with the heart, but having relation to the blood circulation are two sets of nerves: (1) nerves supplying the alary muscles, presumably regulating the pressure in the pericardial cavity, and (2) nerves spreading over the lateral wall of the pericardium in neuropile-like plexuses and supposed to have a neurosecretory function.It is suggested that the centre controlling the blood circulation could be localized in the infraoesophageal ganglion.


In the study of the phenomena of anaphylaxis there are certain points on which some measure of agreement seems to have been attained. In the case of anaphylaxis to soluble proteins, with which alone we are directly concerned in this paper, the majority of investigators probably accept the view that the condition is due to the formation of an antibody of the precipitin type. Concerning the method, however, by which the presence of this antibody causes the specific sensitiveness, the means by which its interaction with the antibody produces the anaphylactic shock, there is a wide divergence of conception. Two main currents of speculation can be discerned. One view, historically rather the earlier, and first put forward by Besredka (1) attributes the anaphylactic condition to the location of the antibody in the body cells. There is not complete unanimity among adherents of this view as to the nature of the antibody concerned, or as to the class of cells containing it which are primarily affected in the anaphylactic shock. Besredka (2) himself has apparently not accepted the identification of the anaphylactic antibody with a precipitin, but regards it as belonging to a special class (sensibilisine). He also regards the cells of the central nervous system as those primarily involved in the anaphylactic shock in the guinea-pig. Others, including one of us (3), have found no adequate reason for rejecting the strong evidence in favour of the precipitin nature of the anaphylactic antibody, produced by Doerr and Russ (4), Weil (5), and others, and have accepted and confirmed the description of the rapid anaphylactic death in the guinea-pig as due to a direct stimulation of the plain-muscle fibres surrounding the bronchioles, causing valve-like obstruction of the lumen, and leading to asphyxia, with the characteristic fixed distension of the lungs, as first described by Auer and Lewis (6), and almost simultaneously by Biedl and Kraus (7). But the fundamental conception of anaphylaxis as due to cellular location of an antibody, and of the reaction as due to the union of antigen and antibody taking place in the protoplasm, is common to a number of workers who thus differ on details.


Development ◽  
1964 ◽  
Vol 12 (2) ◽  
pp. 317-331
Author(s):  
D. O. E. Gebhardt ◽  
P. D. Nieuwkoop

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.


1957 ◽  
Vol 34 (3) ◽  
pp. 306-333
Author(s):  
G. M. HUGHES

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.


1927 ◽  
Vol 23 (10) ◽  
pp. 1046-1050
Author(s):  
E. V. Sukhova

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.


2020 ◽  
Vol V (4) ◽  
pp. 16-46
Author(s):  
F. K. Telyatnik

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.


2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Domenico De Berardis ◽  
Stefano Marini ◽  
Monica Piersanti ◽  
Marilde Cavuto ◽  
Giampaolo Perna ◽  
...  

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.


1959 ◽  
Vol 36 (3) ◽  
pp. 501-511
Author(s):  
M. J. WELLS

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.


1975 ◽  
Vol 65 (3) ◽  
pp. 255-273 ◽  
Author(s):  
J H Schwartz ◽  
M L Eisenstadt ◽  
H Cedar

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.


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