Escape from Recurring Tactile Stimulation in Branchiomma Vesiculosum

1965 ◽  
Vol 42 (2) ◽  
pp. 307-322 ◽  
Author(s):  
FRANKLIN B. KRASNE
Keyword(s):  
Ventral Nerve Cord ◽  
Tactile Stimulation ◽  
The Body ◽  
Direct Stimulation ◽  
Giant Fibre ◽  
Sensory Ending ◽  
Tactile Stimuli ◽  
Escape Reflex ◽  
Giant Fibres ◽  
Stimulation Of

1. Branchiomma's rapid escape from tactile stimuli is mediated by the pair of giant nerve axons which run the length of the body above the ventral nerve cord. 2. The giant neurons are connected by very stable, polarized junctions to giant motor axons. 3. The giant-fibre escape reflex fails if tactile stimuli are repeated; a non-giant system which continues to cause slower escape eventually fails also. 4. Recovery from reflex failure is slow. 5. The failure of the rapid escape reflex occurs prior to the giant fibre. It is not primarily due to sensory ending accommodation. It cannot be caused by direct stimulation of the giant fibres.

The Giant Fibre Reflex of the Earthworm, Lumbricus Terrestris L

1962 ◽  
Vol 39 (2) ◽  
pp. 219-227
Author(s):  
M. B. V. ROBERTS
Keyword(s):  
Nerve Cord ◽  
Lumbricus Terrestris ◽  
The Body ◽  
Muscle Preparation ◽  
Direct Stimulation ◽  
Giant Fibre ◽  
Low Threshold ◽  
Giant Fibres ◽  
Nerve Muscle ◽  
Stimulation Of

1. A nerve-muscle preparation including the longitudinal musculature and the giant fibres in the nerve cord of the earthworm is described. 2. Direct stimulation of the nerve cord with single shocks of increasing intensity results in two types of response: (a) a low threshold, very small twitch, resulting from a single impulse in the median giant fibre, and (b) a higher threshold, slightly larger twitch, resulting from single impulses in the median and lateral giant fibres. Both responses are highly susceptible to fatigue. 3. Stimulation of the body surface evokes a much more powerful contraction which is associated with a burst of impulses in the giant fibre. The strength of the contraction depends upon the number of impulses in the burst and this in turn upon the intensity and duration of the stimulus.

Role of central interneurons in habituation of swimming activity in the medicinal leech

1986 ◽  
Vol 55 (5) ◽  
pp. 977-994 ◽  
Author(s):  
E. A. Debski ◽  
W. O. Friesen
Keyword(s):  
Tactile Stimulation ◽  
Body Wall ◽  
The Body ◽  
Swimming Activity ◽  
Cycle Period ◽  
Direct Stimulation ◽  
Impulse Frequency ◽  
Neuronal Mechanisms ◽  
Intracellular Stimulation ◽  
Stimulation Of

Swimming activity evoked by light tactile stimulation of a body wall flap in dissected leech preparations undergoes habituation (5). In this study, we examine the activity of several interneurons (cell 204, cell 205, the S cell, and cell 208) during habituation trials to study further the neuronal mechanisms that mediate this decline in responsiveness. Light tactile stimulation of the leech body wall evoked initially a marked excitatory response in cell 204 homologs (segmental swim-initiating neurons) that preceded the initiation of swimming activity. This response decreased over the course of repeated stimulus trials; however, no marked decline in cell 204 activity accompanied the cessation of swim initiation. A similar activity pattern was observed in cell 205. Thus the habituation of swimming activity to stroking of the body wall is not due solely to reduced input to cell 204 and cell 205. The early activity of cell 204 was not correlated to the duration of subsequent swim episodes. However, the impulse frequency of cell 204 during swim episodes was negatively correlated to the period of swim cycles. This correlation between cell 204 activity and cycle period occurred both within individual episodes as well as between trials in a habituation series. Direct stimulation of cell 204 with current pulses evoked swimming activity reliably for an average of 72 trials. Therefore, habituation that results from stroking the body wall (which occurs after approximately 6 trials) is not mediated by plasticity in the connections between cell 204 and the swim oscillator. The S cell fired repeatedly in response to light tactile stimulation. This response declined with repeated trials. Intense intracellular stimulation of the S cell was sufficient to initiate swimming activity in some preparations. The magnitude and duration of the excitation required to initiate swimming by this means were far greater, however, than that which occurred during stroking the body wall. The response of cell 208 (a swim oscillator cell) to body wall stimulation during habituation trials was variable; usually an initial hyperpolarization was followed by some depolarization. No aspect of this response correlated with the onset of habituation. Our results are consistent with the idea that cell 204 and cell 205 are part of the pathway that mediates swimming activity in response to light tactile stimulation of the leech body wall, and that habituation occurs, in part, as the result of reduced sensory input to this cell.(ABSTRACT TRUNCATED AT 400 WORDS)

THE HISTOLOGY OF THE GIANT FIBRE SYSTEM IN THE ABDOMINAL VENTRAL NERVE CORD OF THE DESERT LOCUST

1970 ◽  
Vol 102 (9) ◽  
pp. 1163-1168 ◽  
Author(s):  
W. D. Seabrook
Keyword(s):  
Single Cell ◽  
Nerve Cord ◽  
Ventral Nerve Cord ◽  
Schistocerca Gregaria ◽  
Desert Locust ◽  
Giant Fibre ◽  
Metathoracic Ganglion ◽  
Giant Fibres ◽  
Giant Fibre System

AbstractSchistocerca gregaria possess four neurones of giant fibre proportions within the abdominal ventral nerve cord. These fibres arise from single cell bodies in the terminal ganglionic mass and pass without interruption to the metathoracic ganglion. Fibres become reduced in diameter when passing through a ganglion. Branching of the giant fibres occurs in abdominal ganglia 6 and 7.

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.

Structure and Function of the Lateral Giant Neurone of the Primitive Crustacean Anaspides Tasmaniae

1979 ◽  
Vol 78 (1) ◽  
pp. 121-136
Author(s):  
GERALD E. SILVEY ◽  
IAN S. WILSON
Keyword(s):  
Action Potentials ◽  
Tactile Stimulation ◽  
Large Diameter ◽  
Whole Body ◽  
Giant Fibre ◽  
Single Action ◽  
Giant Neurone ◽  
And Function ◽  
Thoracic And Abdominal ◽  
Stimulation Of

The syncarid crustacean Anaspides tasmaniae rapidly flexes its free thoracic and abdominal segments in response to tactile stimulation of its body. This response decrements but recovers in slightly more than one hour. The fast flexion is evoked by single action potentials in the lateral of two large diameter fibres (40 μm) which lie on either side of the cord. The lateral giant fibre is made up of fused axons of 11 neurones, one in each of the last 5 thoracic and 6 abdominal ganglia. The soma of each neurone lies contralateral to the axon. Its neurite crosses that of its counterpart in the commissure and gives out dendrites into the neuropile of each hemiganglion. The lateral giant neurone receives input from the whole body but fires in response only to input from the fourth thoracic segment posteriorly. Both fibres respond with tactile stimulation of only one side. Since neither current nor action potentials spread from one fibre to the other, afferents must synapse with both giant neurones. The close morphological and physiological similarities of the lateral giant neurone in Anaspides to that in the crayfish (Eucarida) suggest that the lateral giant system arose in the ancestor common to syncarids and eucarids, prior to the Carboniferous.

The locust jump. I. The motor programme

1977 ◽  
Vol 66 (1) ◽  
pp. 203-219
Author(s):  
W. J. Heitler ◽  
M. Burrows
Keyword(s):  
High Frequency ◽  
Tactile Stimulation ◽  
The Body ◽  
Flexor Muscle ◽  
Tactile Stimuli ◽  
Extensor Muscles ◽  
Trigger Activity ◽  
Three Stages ◽  
Motor Programme ◽  
Made In

A motor programme is described for defensive kicking in the locust which is also probably the programme for jumping. The method of analysis has been to make intracellular recordings from the somata of identified motornuerones which control the metathoracic tibiae while defensive kicks are made in response to tactile stimuli. Three stages are recognized in the programme. (1) Initial flexion of the tibiae results from the low spike threshold of tibial flexor motorneurones to tactile stimulation of the body. (2) Co-contraction of flexor and extensor muscles followa in which flexor and extensor excitor motoneurones spike at high frequency for 300-600 ms. the tibia flexed while the extensor muscle develops tension isometrically to the level required for a kick or jump. (3) Trigger activity terminates the co-contraction by inhibiting the flexor excitor motorneurones and simultaneously exciting the flexor inhibitors. This causes relaxation of the flexor muscle and allows the tibiae to extend. If the trigger activity does not occur, the jump or kick is aborted, and the tibiae remain flexed.

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 Non-informative vision improves spatial tactile discrimination on the shoulder but does not influence detection sensitivity

2020 ◽  
Vol 238 (12) ◽  
pp. 2865-2875
Author(s):  
Fabrizio Leo ◽  
Sara Nataletti ◽  
Luca Brayda
Keyword(s):  
Tactile Stimulation ◽  
Detection Threshold ◽  
Receptive Fields ◽  
Judgment Task ◽  
The Body ◽  
Detection Sensitivity ◽  
Body Parts ◽  
Tactile Acuity ◽  
Tactile Stimuli ◽  
Numerosity Judgment

Abstract Vision of the body has been reported to improve tactile acuity even when vision is not informative about the actual tactile stimulation. However, it is currently unclear whether this effect is limited to body parts such as hand, forearm or foot that can be normally viewed, or it also generalizes to body locations, such as the shoulder, that are rarely before our own eyes. In this study, subjects consecutively performed a detection threshold task and a numerosity judgment task of tactile stimuli on the shoulder. Meanwhile, they watched either a real-time video showing their shoulder or simply a fixation cross as control condition. We show that non-informative vision improves tactile numerosity judgment which might involve tactile acuity, but not tactile sensitivity. Furthermore, the improvement in tactile accuracy modulated by vision seems to be due to an enhanced ability in discriminating the number of adjacent active electrodes. These results are consistent with the view that bimodal visuotactile neurons sharp tactile receptive fields in an early somatosensory map, probably via top-down modulation of lateral inhibition.

Response properties and synaptic connections of mechanoafferent neurons in cerebral ganglion of Aplysia

1979 ◽  
Vol 42 (4) ◽  
pp. 954-974 ◽  
Author(s):  
S. C. Rosen ◽  
K. R. Weiss ◽  
I. Kupfermann
Keyword(s):  
Receptive Field ◽  
Motor Neurons ◽  
Receptive Fields ◽  
Cerebral Ganglion ◽  
The Body ◽  
Sensory Response ◽  
Tactile Stimuli ◽  
Dorsal Portion ◽  
Intracellular Stimulation ◽  
Stimulation Of

1. The cells of two clusters of small neurons on the ventrocaudal surface of each hemicerebral ganglion of Aplysia were found to exhibit action potentials following tactile stimuli applied to the skin of the head. These neurons appear to be mechanosensory afferents since they possess axons in the nerves innervating the skin and tactile stimulation evokes spikes with no prepotentials, even when the cell bodies are sufficiently hyperpolarized to block some spikes. The mechanosensory afferents may be primary afferents since the sensory response persists after chemical synaptic transmission is blocked by bathing the ganglion and peripheral structures in seawater with a high-Mg2+ and low-Ca2+ content. 2. The mechanosensory afferents are normally silent and are insensitive to photic, thermal, and chemical stimuli. A punctate tactile stimulus applied to a circumscribed region of skin can evoke a burst of spikes. If the stimulus is maintained at a constant forces, the mechanosensory response slowly adapts over a period of seconds. Repeated brief stimuli have little or no effect on spike frequency within a burst. 3. Approximately 81% of the mechanoafferent neurons have a single ipsilateral receptive field. The fields are located on the lips, the anterior tentacles, the dorsal portion of the head, the neck, or the perioral zone. Because many cells have collateral axons in the cerebral connectives, receptive fields elsewhere on the body are a possibility. The highest receptive-field density was associated with the lips. Within each area, receptive fields vary in size and shape. Adjacent fields overlap and larger fields frequently encompass several smaller ones. The features of some fields appear invariant from one animal to the next. A loose form of topographic organization of the mechanoafferent cells was observed. For example, cells located in the medial cluster have lip receptive fields, and most cells in the posterolateral portion of the lateral clusters have tentacle receptive fields. 4. Intracellular stimulation of individual mechanoafferents evokes short and constant-latency EPSPs in putative motor neurons comprising the identified B-cell clusters of the cerebral ganglion. On the basis of several criteria, these EPSPs appear to be several criteria, these EPSPs appear to be chemically mediated and are monosynaptic. 5. Repetitive intracellular stimulation of individual mechanoafferent neurons at low rates results in a gradual decrement in the amplitude of the EPSPs evoked in B cluster neurons. EPSP amplitude can be restored following brief periods of rest, but subsequent stimulation leads to further diminution of the response. 6. A decremented response cannot be restored by strong mechanical stimulation outside the receptive field of the mechanoafferent or by electrical stimulation of the cerebral nerves or connectives...

Afferent projections to the lateral cervical nucleus: a microelectrode study

1963 ◽  
Vol 204 (4) ◽  
pp. 667-672 ◽  
Author(s):  
F. Morin ◽  
S. T. Kitai ◽  
H. Portnoy ◽  
C. Demirjian
Keyword(s):  
Tactile Stimulation ◽  
The Body ◽  
Joint Movement ◽  
Single Neurons ◽  
Small Areas ◽  
Afferent Projections ◽  
Lateral Cervical Nucleus ◽  
Degree Of Convergence ◽  
High Degree ◽  
Stimulation Of

The lateral cervical nucleus was explored with microelectrodes in lightly anesthetized cats. Extracellular responses were recorded from 160 neurons following physiological stimulation of the ipsilateral side of the body from the neck to the tail. The stimuli activating the neurons were touch, pressure, and joint movement. Neurons responding to touch were more prevalent than neurons responding to pressure on the skin or on deep structures; those responding to joint movements were a small fraction of the neuronal sample studied. For the three stimuli tested, the limbs were more prominently represented than the trunk. Tactile and pressure peripheral fields activating single neurons were of three types: restricted (a few hairs, small areas within one segment of a limb), large (wide areas of the trunk, whole limb), and very large (whole ipsilateral aspect of the body, both limbs). Restricted fields were less numerous than the large fields. One-third of the fields activating single neurons following tactile stimulation was of the very large type. The existence of the very large fields indicated a high degree of convergence of afferents onto neurons of the cervical nucleus.

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