scholarly journals On the Excitation of Crustacean Muscle. I

1934 ◽  
Vol 11 (1) ◽  
pp. 11-27 ◽  
Author(s):  
C. F. A. PANTIN
Keyword(s):  
Latent Period ◽  
Good Condition ◽  
Carcinus Maenas ◽  
Muscle Fibres ◽  
Direct Stimulation ◽  
Contractile Mechanism ◽  
Crustacean Muscle ◽  
Slow Type ◽  
Slow Contraction ◽  
Stimulation Of

1. A brief account is given of the present position of the problem of neuromuscular action in the Crustacea. 2. A method is described by which the leg of Carcinus maenas may be perfused and stimulated. By this method the muscle remains in good condition for some 8 hours. 3. By stimulating the nerve in Carcinus leg with alternating currents of increasing intensity a series of varied responses is obtained. Above the threshold a contraction is developed of a comparatively slow type. With increase of intensity of the stimulus the response fails, owing to the excitation of inhibitory nerves. But at still greater intensities contraction reappears. This contraction, however, is very rapid. Tetani developed from the slow contraction are easily inhibited. Tetani developed from the rapid contraction cannot be inhibited by superimposed stimuli. 4. The relation of the quick and slow contractions is considered. It is not possible to fatigue one without fatiguing the other. Experiments show that on suddenly releasing the tension of the muscle during a tetanus, the tension always redevelops in a manner similar to the development of tension in the quick contraction, even though the tetanus be developed initially by the slow contraction. The same contractile mechanism is involved in both cases. 5. The latent period of contraction on stimulation of the nerve is very long, and ranges from 300σ at the threshold. That for direct stimulation of the muscle is 7-1Oσ. Above the threshold the latent period shortens rapidly with increasing stimulus. Over this region the contractions are of the slow type. The latent period becomes asymptotic to 50σ as the intensity is increased. At this value the contractions are of the quick type. Inhibition is effective where the latent period begins to approach its asymptotic value. 6. It is suggested that all the varied phenomena observed are related to the power of summation of crustacean muscle; that the slow contraction in response to a battery of stimuli is not due to a different contractile mechanism from the quick one, but that it is a summation effect by which a statistically increasing number of muscle fibres are brought into action as successive impulses pass down the nerve.

scholarly journals The Motor Innervation of a Triply Innervated Crustacean Muscle

1939 ◽  
Vol 16 (4) ◽  
pp. 398-402
Author(s):  
A. VAN HARREVELD
Keyword(s):  
Mechanical Injury ◽  
Muscle Fibres ◽  
Motor Innervation ◽  
Nerve Fibres ◽  
Crustacean Muscle ◽  
Conduction Process ◽  
Slow Contraction ◽  
Stimulation Of

The crustacean muscle is extremely sensitive to mechanical injury. This is due to the fact that the muscle fibres are innervated by a feltwork of nerve fibres which surrounds them. Apparéntly, there is a lack of a muscular conduction process in these muscles. Contractions have been observed in the same muscle fibres during stimulation of the axon for the fast contraction as well as during stimulation of the fibre for the slow contraction.

scholarly journals VI. —Anaphylaxis and anaphylatoxins

1923 ◽  
Vol 211 (382-390) ◽  
pp. 273-315 ◽  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Guinea Pig ◽  
Anaphylactic Shock ◽  
The Body ◽  
Muscle Fibres ◽  
Direct Stimulation ◽  
Fundamental Conception ◽  
The Central Nervous System ◽  
Stimulation Of

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.

THE EFFECT OF THYROID HORMONE ON THE RATE OF BOTH NEUROMUSCULAR AND MUSCULAR FAILURE IN ADRENALECTOMIZED MICE MAINTAINED ON SALT

1958 ◽  
Vol 17 (2) ◽  
pp. 134-142 ◽  
Author(s):  
MARY F. LOCKETT ◽  
S. N. GANJU
Keyword(s):  
Thyroid Hormone ◽  
Thyroid Gland ◽  
Nerve Stimulation ◽  
Early Onset ◽  
Dose Effect ◽  
Muscle Fibres ◽  
Rat Diaphragm ◽  
Direct Stimulation ◽  
Normal Rat ◽  
Stimulation Of

SUMMARY Pretreatment of salt-maintained adrenalectomized mice for 6 days with 3–6 mg dried thyroid gland, or with 0·25 μg of either l-thyroxine or l-triiodothyronine, per mouse per day, delayed the early onset of both neuromuscular and muscular failure which are characteristic of these animals. Dose-effect curves for the action of thyroxine on the myoneural junctions and striped muscle fibres are given. A concentration of 0·05μg l-triiodothyronine/100 ml. bath fluid antagonized potassium reduction of the maximal twitch of the normal rat diaphragm in response to nerve stimulation, but not in response to direct stimulation of the curarized muscle.

Memoirs: The Neuro-Muscular Mechanism of the Gill of Pecten

1930 ◽  
Vol s2-73 (291) ◽  
pp. 365-392
Author(s):  
S. B. SETNA
Keyword(s):  
Feeding Habits ◽  
Adductor Muscle ◽  
The Body ◽  
Muscle Fibres ◽  
Direct Stimulation ◽  
Gill Filaments ◽  
Lateral Extent ◽  
Branchial Nerve ◽  
The Individual ◽  
Stimulation Of

Experimental. 1. The contraction of the adductor-muscle which follows stimulation of the palial nerve is preceded by a marked contraction of the ctenidial axis, so that the gill contracts before the adductor-muscle becomes active. This movement of the ctenidium is abolished if the main branchial nerve is cut near its origin. 2. The gills of Pecten possess a neuromuscular mechanism which is to some extent independent of the rest of the body, so that excised gills when stimulated react in the same way as an attached gill. 3. The lamellae of the gill possess two distinct types of movement. (a) When the surface of the gill is stimulated by contact with a glass rod or by carmine particles, the frontal surfaces of the two lamellae approach each other; the movement very often being executed by the lamella which is not actually being stimulated. The lateral extent of these movements (concertina movements) is roughly proportional to the intensity of the stimulus. Such movements normally appear to transfer the bulk of the material on to the mantle. Separation of the main branchial nerve abolishes these movements. (b) Each principal filament is capable of moving the ordinary filaments to which it is attached. This movement (flapping movement) is due to the movements of the interfilamentar junctions which alternatively move up and down at right angles to their length. This motion is independent of the branchial nerve and can be produced by direct stimulation of very tiny pieces of the individual filaments. 4. The significance of gill movements to feeding habits is discussed. The course of food particles depends on the nature of the stimuli affecting the gill. Histological. 5. The ctenidial axis and the principal filaments have a stratum of anastomosing nerve-cells which appear to form a true nerve-net comparable to that of the mantle. 6. The gill receives nerve-fibres from two sources, the brain and the visceral ganglion. The subsidiary branchial nerve is a structure hitherto unknown in the molluscan gill; so far its function is unknown. Each gill has four main longitudinal nerve-trunks. 7. The osphradium of the gill has a much more extensive distribution than has hitherto been supposed. 8. Two sets of muscles exist at the base of the gill-filaments, and these are responsible for movements of the lamellae. The muscle-fibres are non-striated. 9. The principal filaments are connected to the ordinary filaments by processes containing true muscle-cells, and by these cells movements of the filaments are effected.

scholarly journals The effect of muscular contraction upon the blood flow in the skeletal muscle, in the diaphragm and in the small intestine

1934 ◽  
Vol 114 (788) ◽  
pp. 245-257 ◽  
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Motor Nerve ◽  
Muscular Contraction ◽  
Muscle Fibres ◽  
Direct Stimulation ◽  
Direct Excitation ◽  
Previous Communication ◽  
Arterial Inflow ◽  
Stimulation Of

In the previous communication, p. 233, experiments were described dealing with the effect of contraction of the skeletal muscle upon its blood flow. Short and prolonged tetanic contractions were evoked in various skeletal muscles by stimulation of their cut or uncut motor nerve or by direct stimulation of the muscle. Stimulation of the motor nerve as well as that of the muscle ma involve to an unknown extent the vasomotor innervation of the respective muscles and, although strong evidence was provided that none of the effects observed were even in part due to a direct excitation of the vasomotor fibres, we thought it necessary to repeat our experiments under conditions in which direct excitation of vasomotor fibres is definitely avoided. The present communication describes experiments on the reflex contraction of the tibialis and of the quadriceps femoris (vastocrureus) muscles. So far as we are aware, there is only one reference in the literature which related to circulatory conditions in muscles during a reflex contraction. Denny-Brown (1929), by direct microsopical observations of the surface of the soleus muscle during a stretch reflex, noticed that even a modest amount of pull on the tendon opens up numerous capillaries and hastens the flow of blood in them to a remarkable extent. The tension developed was sometimes as great as 1∙5 kg. Weight. As a result of this observation, Denny-Brown believes that the capillaries are not compressed by the muscle fibres when these contract reflexly. It is, however, quite likely that the circulatory conditions in the superficial layers of the muscle differ from those in the depth of the muscle. Moreover, it is extremely difficult to remove completely all the connective tissue from the surface of the muscle, and we know from Rein's experiments (Keller, Loeser, and Rein, 1930), as well as from our own previous experiments (Anrep, Blalock, and Samaan, 1933), that during the contraction of a muscle there may be considerable dilatation in the resting tissues. In order to determine the total arterial inflow into the tibialis anticus during its reflex contraction, we performed experiments which were similar to those described in our previous communication.

scholarly journals Neuromuscular activity in sea anemone Calliactis parasitica (Couch)

1958 ◽  
Vol 37 (3) ◽  
pp. 789-805 ◽  
Author(s):  
Mary Needler ◽  
D. M. Ross
Keyword(s):  
Latent Period ◽  
Spontaneous Activity ◽  
Hermit Crab ◽  
Sea Anemone ◽  
Slow Movement ◽  
Neuromuscular Activity ◽  
Contractile Mechanism ◽  
Calliactis Parasitica ◽  
Slow Contraction ◽  
Marginal Region

In a recent study (Ross, 1957) isolated marginal sphincter preparations of the sea anemone, Calliactis parasitica, showed two distinct responses to stimulation: (1) a quick contraction in response to stimuli at frequencies from 0–2 to 3–0 sec, the facilitated response of Pantin (1935 a) beginning only on the second stimulus of a series, with a latent period of about 0 1 sec; (2) a smooth slow contraction in response to stimuli at lower frequencies, with a latent period of not less than 30 sec, and beginning only after several stimuli. This slow movement of the marginal region had not been detected in work on whole animals, but it is similar to the contractions of the ‘slow’ muscles of Calliactis (Pantin, 1935 b) and Metridium (Batham & Pantin, 1950 a). However, Calliactis sphincter shows almost no spontaneous activity.Both quick and slow contractions had previously been observed in excised sphincters and mesenteric retractors of Metridium (Batham & Pantin, 1954), the chief muscles utilized in the closure of that animal. In all these cases, the quick contraction would seem to be a specialized mechanism for sudden withdrawal superimposed upon, and perhaps developed from, a more primitive and general slow contractile mechanism. As part of a programme to investigate and compare the properties of quick and slow contractions in these muscles it seemed desirable to see what part, if any, slow contractions of the marginal sphincter play in the life of Calliactis. This involved us in a wider study of the neuromuscular activity of this anemone which normally lives on shells inhabited by the hermit crab, Eupagurus bernhardus.

scholarly journals On The Excitation of Crustacean Muscle

1936 ◽  
Vol 13 (1) ◽  
pp. 111-130
Author(s):  
C. F. A. PANTIN
Keyword(s):  
Refractory Period ◽  
Motor Nerve ◽  
Carcinus Maenas ◽  
Motor Units ◽  
Repetitive Stimulation ◽  
Muscle Fibres ◽  
Absolute Refractory Period ◽  
Excitable System ◽  
Crustacean Muscle ◽  
The Absolute

1. The response of certain limb muscles in Carcinus maenas to stimuli of different frequencies and intensities has been analysed. The precautions necessary to obtain reproducible results in crustacean muscle are recorded. The material must be fresh; the duration of stimulation short; and each individual shock must be less than the true chronaxie, to prevent multiple excitation of the nerve. 2. A single stimulus produces a microscopic response or none at all. A succession of shocks, however, causes a contraction, the rate of which increases with the frequency, till this reaches the high values of 300-400 shocks per sec. The rate of contraction varies absolutely continuously with the frequency from 300 per sec. down to the microscopic response observed at less than 10 per sec. The rate of contraction increases very rapidly indeed between frequencies of 50 and 200 per sec, so that this range includes almost all rates of contraction. 3. The limiting frequency of 300-400 per sec. is close to the refractory period. For pairs of stimuli, the absolute refractory period is about 1σ at 18° C. This is followed by a relative refractory phase and sometimes by a supernormal phase. The excitability has returned to normal after about 4σ. In repetitive stimulation the absolute refractory period lengthens. 4. With stimuli of increasing intensity, the responses of both flexor and extensor muscles show first a threshold for excitation of the motor nerve, and, at a higher intensity, a threshold for inhibition. At very high intensities (10-20 times the true threshold) large contractions may be obtained owing to repetitive excitation. 5. With suitable precautions it can be shown that between the threshold of excitation and the threshold of inhibition there is great independence between the response and the intensity of the stimulus. The system behaves as a single excitable system and possibly in some cases a single axon supplies the entire muscle. 6. The chronaxie of the nerve to single shocks and to repetitive stimulation is of the order of 0.2-0.4σ. Single shocks of high intensity give multiple excitation, and the thresholds for this simulate a chronaxie curve. False chronaxies up to 30σ can be obtained in this way. 7. There is no evidence of a double excitable system in the muscles of the walking leg of Carcinus such as has sometimes been recorded in crustacean claws. There is no doubling of intensity-duration or refractory period curves. 8. All the effects observed are explicable in terms of neuromuscular facilitation. The response is governed entirely by the frequency and number of stimuli. Each shock in a series brings more and more muscle fibres into action. With increasing frequency of stimulation, not only are there more contraction increments in a given time, but the increment following each shock is larger. 9. At low and moderate frequencies the rate of development of tension is governed by the rate at which impulses reach the muscle. At the highest frequencies a limit is set to the rate of contraction by the physical properties of the muscle. 10. There is a close analogy between the neuromuscular mechanism disclosed here and the neuromuscular mechanism of the Coelenterata. In both there is a tendency for an entire effector to behave as a single system in which the response is governed by the number and frequency of impulses received by the muscle. This system is distinguished sharply from that of vertebrate skeletal muscle in which gradation of response is brought about through the multiplicity of motor units.

scholarly journals The Photoreceptors of Lampreys

1935 ◽  
Vol 12 (3) ◽  
pp. 229-238 ◽  
Author(s):  
J. Z. YOUNG
Keyword(s):  
Spinal Cord ◽  
Latent Period ◽  
Lateral Line ◽  
The Body ◽  
Direct Stimulation ◽  
Normal Behaviour ◽  
Motor Responses ◽  
Lateral Line Nerve ◽  
Stimulation Of ◽  
Do So

1. The tail of larval and adult L. planeri and adult L. fluviatilis contains a photoreceptive mechanism involving an initial short sensitization period, and a latent period. 2. The impulses initiated by the photochemical change are carried in the lateral line nerves, as is shown by the facts that section of these nerves abolishes the response, whereas section of the spinal cord does not do so. 3. Motor responses are only occasionally seen after illumination of parts of the body other than the tail. These responses are apparently due to direct stimulation of the spinal cord, and can be regularly elicited if the pigment protecting the latter be removed. 4. Motor responses may follow illumination of the head, either of larvae or adults, but only after illumination periods much longer than are necessary to obtain a response from the tail. 5. The responses play a part in the normal behaviour of the animals by assisting them to bury themselves completely in the mud. 6. The stimulus of illumination of the tail simply initiates swimming movements, and there is no orientation of the animal with reference to the direction of the light. This is confirmed by the observation that, following illumination of the tail from one side, the first movement of the head may be either towards or away from the side stimulated. Further, after section of one lateral line nerve only no forced movements occur on illumination. The reaction may thus be described as a photokinesis, and does not involve any true topotaxis, its effect is to prevent the animal remaining in any illuminated area.

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