TONIC ADAPTIONS IN DEAFFERENTED LIMBS OF THE CAT

1955 ◽  
Vol 33 (1) ◽  
pp. 139-155
Author(s):  
R. D. Teasdall ◽  
G. W. Stavraky
Keyword(s):  
Hind Limb ◽  
Muscle Tone ◽  
Receptive Fields ◽  
Linear Acceleration ◽  
The Body ◽  
Nerve Roots ◽  
Normal Response ◽  
Postural Reflexes ◽  
Reflex Arc ◽  
Spinal Neurones

In 26 cats postural reflexes and tonic adjustments in the chronically deafferented and intact limbs were studied by means of moving picture and other photographic recordings for a period of four to six months. The positive supporting reactions which were dependent on an intrinsic reflex arc were permanently abolished by the deafferentation. Other segmental reflexes such as the crossed extensor and Philippson's reflex were readily elicited in the deafterented extremity within 24 to 48 hr. after section of the posterior nerve roots, and after longer intervals following the deafferentation these reflexes became greatly exaggerated. They appeared sooner after the operation and became more prominent in the hind limb than in the fore limb.The intersegmental postural reflexes and the scratch reflex were consistently present in the deafferented limbs of chronic animals and the latter reflex became markedly hyperactive within one week after section of the posterior nerve roots. The normal reflex responses to linear acceleration were first depressed by section of the posterior nerve roots, but in one to four weeks after the operation they were readily demonstrable, became exaggerated in the deafferented extremity, and remained so for the rest of the period of observation. Unlike the crossed extensor reflex, these reflexes reappeared first in the fore limb and reached greater prominence in this extremity than they did in the hind limb. A reversal of the tonic labyrinthine and neck reflexes was demonstrated in the deafferented extremities of the chronic animal. This reversal appeared one to two months after section of the posterior nerve roots in the fore limb, and two to three months following deafferentation of the hind limb. When established, the reversal was readily elicited and took place simultaneously with a normal response in the intact extremities on the opposite side of the body. Simultaneously with the changes in postural reflexes, alterations in tone became prominent.The modified and exaggerated postural reflexes and tonic adjustments observed in the deafferented limbs were attributed to a sensitization of the partially denervated spinal neurones to nerve impulses reaching them from various receptive fields other than those originating in the extremity itself. It is felt that the modifications in postural reflexes and subsequent alterations of muscle tone which have been demonstrated in the chronically deafferented extremities of animals may play an important part in the pathogenesis of human sensory ataxia.

TONIC ADAPTIONS IN DEAFFERENTED LIMBS OF THE CAT

1955 ◽  
Vol 33 (2) ◽  
pp. 139-155 ◽  
Author(s):  
R. D. Teasdall ◽  
G. W. Stavraky
Keyword(s):  
Hind Limb ◽  
Muscle Tone ◽  
Receptive Fields ◽  
Linear Acceleration ◽  
The Body ◽  
Nerve Roots ◽  
Normal Response ◽  
Postural Reflexes ◽  
Reflex Arc ◽  
Spinal Neurones

In 26 cats postural reflexes and tonic adjustments in the chronically deafferented and intact limbs were studied by means of moving picture and other photographic recordings for a period of four to six months. The positive supporting reactions which were dependent on an intrinsic reflex arc were permanently abolished by the deafferentation. Other segmental reflexes such as the crossed extensor and Philippson's reflex were readily elicited in the deafterented extremity within 24 to 48 hr. after section of the posterior nerve roots, and after longer intervals following the deafferentation these reflexes became greatly exaggerated. They appeared sooner after the operation and became more prominent in the hind limb than in the fore limb.The intersegmental postural reflexes and the scratch reflex were consistently present in the deafferented limbs of chronic animals and the latter reflex became markedly hyperactive within one week after section of the posterior nerve roots. The normal reflex responses to linear acceleration were first depressed by section of the posterior nerve roots, but in one to four weeks after the operation they were readily demonstrable, became exaggerated in the deafferented extremity, and remained so for the rest of the period of observation. Unlike the crossed extensor reflex, these reflexes reappeared first in the fore limb and reached greater prominence in this extremity than they did in the hind limb. A reversal of the tonic labyrinthine and neck reflexes was demonstrated in the deafferented extremities of the chronic animal. This reversal appeared one to two months after section of the posterior nerve roots in the fore limb, and two to three months following deafferentation of the hind limb. When established, the reversal was readily elicited and took place simultaneously with a normal response in the intact extremities on the opposite side of the body. Simultaneously with the changes in postural reflexes, alterations in tone became prominent.The modified and exaggerated postural reflexes and tonic adjustments observed in the deafferented limbs were attributed to a sensitization of the partially denervated spinal neurones to nerve impulses reaching them from various receptive fields other than those originating in the extremity itself. It is felt that the modifications in postural reflexes and subsequent alterations of muscle tone which have been demonstrated in the chronically deafferented extremities of animals may play an important part in the pathogenesis of human sensory ataxia.

Macroanatomical Structure of the Lumbosacral Plexus and its Branches in the Indigenous Duck

2018 ◽  
Vol 52 (1-4) ◽  
pp. 1-9 ◽  
Author(s):  
MT Hussan ◽  
MS Islam ◽  
J Alam
Keyword(s):  
Hind Limb ◽  
Femoral Nerve ◽  
Morphological Structure ◽  
Spinal Nerve ◽  
The Body ◽  
Lumbar Plexus ◽  
Lumbosacral Plexus ◽  
Sacral Plexus ◽  
Spinal Nerves ◽  
Femoral Cutaneous Nerve

The present study was carried out to determine the morphological structure and the branches of the lumbosacral plexus in the indigenous duck (Anas platyrhynchos domesticus). Six mature indigenous ducks were used in this study. After administering an anesthetic to the birds, the body cavities were opened. The nerves of the lumbosacral plexus were dissected separately and photographed. The lumbosacral plexus consisted of lumbar and sacral plexus innervated to the hind limb. The lumbar plexus was formed by the union of three roots of spinal nerves that included last two and first sacral spinal nerve. Among three roots, second (middle) root was the highest in diameter and the last root was least in diameter. We noticed five branches of the lumbar plexus which included obturator, cutaneous femoral, saphenus, cranial coxal, and the femoral nerve. The six roots of spinal nerves, which contributed to form three trunks, formed the sacral plexus of duck. The three trunks united medial to the acetabular foramen and formed a compact, cylindrical bundle, the ischiatic nerve. The principal branches of the sacral plexus were the tibial and fibular nerves that together made up the ischiatic nerve. Other branches were the caudal coxal nerve, the caudal femoral cutaneous nerve and the muscular branches. This study was the first work on the lumbosacral plexus of duck and its results may serve as a basis for further investigation on this subject.

Osteopathic support of sportsmen during the annual training process

2020 ◽  
pp. 37-43 ◽  
Author(s):  
R. A. Yakupov ◽  
G. I. Safiullina ◽  
A. A. Safiullina ◽  
E. R. Burganov
Keyword(s):  
Musculoskeletal Diseases ◽  
Muscle Tone ◽  
The Body ◽  
Training Process ◽  
Health Maintenance ◽  
Osteopathic Treatment ◽  
Leading Position ◽  
Myofascial Syndrome ◽  
Sports Activities ◽  
Timely Treatment

Introduction. Modern sports places high demands on the functional systems of the body at all stages of the training and competitive processes. High loads create signifi cant background for the occurrence of musculoskeletal diseases, among which the myofascial syndrome (MFS) holds the leading position. MFS negatively affects the functional readiness of the sportsman′s body and is a risk factor for injuries of the musculoskeletal system. In this regard, timely treatment of MFS is important. It creates the conditions for the improvement of sports achievements, for health maintenance and sports longevity. Treatment of patients with MFS should include methods that normalize trophism and muscle tone. Given the problem of doping, the use of non-drug methods, including osteopathy, is preferable. The goal of research — to develop a system of monitoring and osteopathic correction of myofascial disorders (MFD) and to introduce it into the practice of medical and biological support for sportsmen of different categories and levels during the annual training process.Materials and methods. 93 sportsmen (45 women and 48 men), mean age 22,1±1,1 years, representing diffe rent sports were examined. The essence of the proposed system is regular clinical and electroneurophysiological monitoring of the body condition and preventive correction of myofascial disorders in order to exclude their infl uence on the success of sports activities.Results. It was established that the proposed system of monitoring and osteopathic correction led to a signifi cant reduction in clinical and electroneurophysiological manifestations both in local and in extensive forms of myofascial disorders, which allowed to maintain the optimal functional readiness of sportsmen throughout the entire annual training cycle.Conclusion. The system of monitoring and correction of MFS with the use of osteopathic treatment can be one of the elements of medical and biological support for sportsmen during the annual training process.

scholarly journals Development of a new method for assessing otolith function in mice using three-dimensional binocular analysis of the otolith-ocular reflex

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shotaro Harada ◽  
Takao Imai ◽  
Yasumitsu Takimoto ◽  
Yumi Ohta ◽  
Takashi Sato ◽  
...  
Keyword(s):  
Eye Movement ◽  
Three Dimensional ◽  
Vertical Component ◽  
Inertial Force ◽  
Linear Acceleration ◽  
The Body ◽  
Body Axis ◽  
Gravitational Acceleration ◽  
Ocular Reflex ◽  
Translational Movement

AbstractIn the interaural direction, translational linear acceleration is loaded during lateral translational movement and gravitational acceleration is loaded during lateral tilting movement. These two types of acceleration induce eye movements via two kinds of otolith-ocular reflexes to compensate for movement and maintain clear vision: horizontal eye movement during translational movement, and torsional eye movement (torsion) during tilting movement. Although the two types of acceleration cannot be discriminated, the two otolith-ocular reflexes can distinguish them effectively. In the current study, we tested whether lateral-eyed mice exhibit both of these otolith-ocular reflexes. In addition, we propose a new index for assessing the otolith-ocular reflex in mice. During lateral translational movement, mice did not show appropriate horizontal eye movement, but exhibited unnecessary vertical torsion-like eye movement that compensated for the angle between the body axis and gravito-inertial acceleration (GIA; i.e., the sum of gravity and inertial force due to movement) by interpreting GIA as gravity. Using the new index (amplitude of vertical component of eye movement)/(angle between body axis and GIA), the mouse otolith-ocular reflex can be assessed without determining whether the otolith-ocular reflex is induced during translational movement or during tilting movement.

scholarly journals Responses of thalamic neurons to itch- and pain-producing stimuli in rats

2018 ◽  
Vol 120 (3) ◽  
pp. 1119-1134 ◽  
Author(s):  
Brett Lipshetz ◽  
Sergey G. Khasabov ◽  
Hai Truong ◽  
Theoden I. Netoff ◽  
Donald A. Simone ◽  
...  
Keyword(s):  
Single Unit ◽  
Electrophysiological Study ◽  
Receptive Fields ◽  
The Body ◽  
Cell Column ◽  
Thalamic Neurons ◽  
Medial Nucleus ◽  
Anesthetized Rats ◽  
Transmission Of Information ◽  
Posterior Medial Nucleus

Understanding of processing and transmission of information related to itch and pain in the thalamus is incomplete. In fact, no single unit studies of pruriceptive transmission in the thalamus have yet appeared. In urethane-anesthetized rats, we examined responses of 66 thalamic neurons to itch- and pain- inducing stimuli including chloroquine, serotonin, β-alanine, histamine, and capsaicin. Eighty percent of all cells were activated by intradermal injections of one or more pruritogens. Forty percent of tested neurons responded to injection of three, four, or even five agents. Almost half of the examined neurons had mechanically defined receptive fields that extended onto distant areas of the body. Pruriceptive neurons were located within what appeared to be a continuous cell column extending from the posterior triangular nucleus (PoT) caudally to the ventral posterior medial nucleus (VPM) rostrally. All neurons tested within PoT were found to be pruriceptive. In addition, neurons in this nucleus responded at higher frequencies than did those in VPM, an indication that PoT might prove to be a particularly interesting region for additional studies of itch transmission. NEW & NOTEWORTHY Processing of information related to itch within in the thalamus is not well understood, We show in this, the first single-unit electrophysiological study of responses of thalamic neurons to pruritogens, that itch-responsive neurons are concentrated in two nuclei within the rat thalamus, the posterior triangular, and the ventral posterior medial nuclei.

Caudofemoral musculature and the evolution of theropod locomotion

Paleobiology ◽  
1990 ◽  
Vol 16 (2) ◽  
pp. 170-186 ◽  
Author(s):  
Stephen M. Gatesy
Keyword(s):  
Knee Flexion ◽  
Hind Limb ◽  
The Body ◽  
Avian Evolution ◽  
Theropod Dinosaurs ◽  
Data Support ◽  
Caudal Vertebrae ◽  
Longus Muscle

Living crocodilians and limbed lepidosaurs have a large caudofemoralis longus muscle passing from tail to femur. Anatomical and electromyographic data support the conclusion that the caudofemoralis is the principal femoral retractor and thus serves as the primary propulsive muscle of the hind limb. Osteological evidence of both origin and insertion indicates that a substantial caudofemoralis longus was present in archosaurs primitively and was retained in the clades Dinosauria and Theropoda. Derived theropods (e.g., ornithomimids, deinonychosaurs, Archaeopteryx and birds) exhibit features that indicate a reduction in caudofemoral musculature, including fewer caudal vertebrae, diminished caudal transverse processes, distal specialization of the tail, and loss of the fourth trochanter. This trend culminates in ornithurine birds, which have greatly reduced tails and either have a minute caudofemoralis longus or lack the muscle entirely.As derived theropod dinosaurs, birds represent the best living model for reconstructing extinct nonavian theropods. Bipedal, digitigrade locomotion on fully erect limbs is an avian feature inherited from theropod ancestors. However, the primitive saurian mechanisms of balancing the body (with a large tail) and retracting the limb (with the caudofemoralis longus) were abandoned in the course of avian evolution. This strongly suggests that details of the orientation (subhorizontal femur) and movement (primarily knee flexion) of the hind limb in extant birds are more properly viewed as derived, uniquely avian conditions, rather than as retentions of an ancestral dinosaurian pattern. Although many characters often associated with extant birds appeared much earlier in theropod evolution, reconstructing the locomotion of all theropods as completely birdlike ignores a wealth of differences that characterize birds.

scholarly journals Perception of the dynamic visual vertical during sinusoidal linear motion

2017 ◽  
Vol 118 (4) ◽  
pp. 2499-2506 ◽  
Author(s):  
A. Pomante ◽  
L. P. J. Selen ◽  
W. P. Medendorp
Keyword(s):  
Vestibular System ◽  
Spatial Orientation ◽  
Linear Acceleration ◽  
The Body ◽  
Body Motion ◽  
Whole Body ◽  
Linear Motion ◽  
Modeling Framework ◽  
Visual Vertical ◽  
The Brain

The vestibular system provides information for spatial orientation. However, this information is ambiguous: because the otoliths sense the gravitoinertial force, they cannot distinguish gravitational and inertial components. As a consequence, prolonged linear acceleration of the head can be interpreted as tilt, referred to as the somatogravic effect. Previous modeling work suggests that the brain disambiguates the otolith signal according to the rules of Bayesian inference, combining noisy canal cues with the a priori assumption that prolonged linear accelerations are unlikely. Within this modeling framework the noise of the vestibular signals affects the dynamic characteristics of the tilt percept during linear whole-body motion. To test this prediction, we devised a novel paradigm to psychometrically characterize the dynamic visual vertical—as a proxy for the tilt percept—during passive sinusoidal linear motion along the interaural axis (0.33 Hz motion frequency, 1.75 m/s2peak acceleration, 80 cm displacement). While subjects ( n=10) kept fixation on a central body-fixed light, a line was briefly flashed (5 ms) at different phases of the motion, the orientation of which had to be judged relative to gravity. Consistent with the model’s prediction, subjects showed a phase-dependent modulation of the dynamic visual vertical, with a subject-specific phase shift with respect to the imposed acceleration signal. The magnitude of this modulation was smaller than predicted, suggesting a contribution of nonvestibular signals to the dynamic visual vertical. Despite their dampening effect, our findings may point to a link between the noise components in the vestibular system and the characteristics of dynamic visual vertical.NEW & NOTEWORTHY A fundamental question in neuroscience is how the brain processes vestibular signals to infer the orientation of the body and objects in space. We show that, under sinusoidal linear motion, systematic error patterns appear in the disambiguation of linear acceleration and spatial orientation. We discuss the dynamics of these illusory percepts in terms of a dynamic Bayesian model that combines uncertainty in the vestibular signals with priors based on the natural statistics of head motion.

Response to sudden torques about ankle in man: V effects of peripheral ischemia

1983 ◽  
Vol 50 (1) ◽  
pp. 297-312 ◽  
Author(s):  
G. L. Gottlieb ◽  
G. C. Agarwal ◽  
R. J. Jaeger
Keyword(s):  
Motor Response ◽  
Muscle Tone ◽  
H Reflex ◽  
Original Position ◽  
Muscle Twitch ◽  
Peripheral Ischemia ◽  
Below The Knee ◽  
Triggered Reactions ◽  
Anterior Tibial ◽  
Reflex Arc

Sudden dorsiflexions and plantar flexions of the foot were imposed by a torque motor while blood flow to the lower leg was occluded by a sphygmomanometer cuff. Seated subjects were instructed to resist the torques and restore the foot to its original position as rapidly as possible. Measurements of the first two electromyographic (EMG) responses were made in the soleus (SOL) and anterior tibial (TA) muscles. These are the myotatic reflex at about 40 ms and the postmyotatic response at about 120 ms. In the anterior tibial muscle, the myotatic component often occurs at 60- to 90-ms latency and is continuous with the postmyotatic component. After about 20 min of ischemia, there is a rapid and eventually complete loss of the myotatic component of the response in the stretched muscle. Concurrent with the loss of the myotatic reflex there is usually a reduction of the postmyotatic component. The latency of postmyotatic component remains unchanged, even after the myotatic reflex is abolished. Voluntary restoration of the foot to its original position in opposition to the motor torque is delayed and slowed by the time that the myotatic reflex has vanished. By measuring electromyographic responses to visually triggered reactions, we demonstrate that the reduction of the postmyotatic response is not due to failure of the efferent pathway. On this basis we discuss the possible contributions made by myotatic mechanisms to the tasks of load compensation and maintenance of muscle tone. Hoffmann reflexes were evoked in similar experiments with stimulation of the posterior tibial nerve at the popliteal fossa, distal to the cuff. The maximal direct motor response and muscle twitch are unaffected by loss of the H-reflex. Myotatic and Hoffmann reflexes were both evoked with torque perturbations and with a stimulating electrode proximal to a below-the-knee cuff. In this case, the myotatic reflex failed while the maximal H-reflex was slightly facilitated. The loss of the myotatic reflex was accompanied by a modest reduction in the direct motor response to electrical stimulation and a somewhat greater reduction in the postmyotatic response to torque perturbation. The data are interpreted to support a dual role for the primary afferent pathway in the control of voluntary movements. It provides the fastest path for the activation of a stretched muscle to initiate a load-compensating contraction. It also provides a form of servo assistance in modulating descending control signals. The degree of this assistance is estimated. In this simple experimental paradigm, functional contributions of the reflex arc are demonstrated.

Responses of primate SI cortical neurons to noxious stimuli

1983 ◽  
Vol 50 (6) ◽  
pp. 1479-1496 ◽  
Author(s):  
D. R. Kenshalo ◽  
O. Isensee
Keyword(s):  
Receptive Field ◽  
Cortical Neurons ◽  
Receptive Fields ◽  
The Body ◽  
Thermal Stimulation ◽  
Discharge Frequency ◽  
Mechanical Stimuli ◽  
Noxious Heat ◽  
Nociceptive Neurons ◽  
Heat Pulses

Recordings were made from single SI cortical neurons in the anesthetized macaque monkey. Each isolated cortical neuron was tested for responses to a standard series of mechanical stimuli. The stimuli included brushing the skin, pressure, and pinch. The majority of cortical neurons responded with the greatest discharge frequency to brushing the receptive field, but neurons were found in areas 3b and 1 that responded maximally to pinching the receptive field. A total of 68 cortical nociceptive neurons were examined in 10 animals. Cortical neurons that responded maximally to pinching the skin were also tested for responses to graded noxious heat pulses (from 35 to 43, 45, 47, and 50 degrees C). If the neuron failed to respond or only responded to 50 degrees C, the receptive field was also heated to temperatures of 53 and 55 degrees C. Fifty-six of the total population of nociceptive neurons were tested for responses to the complete series of noxious heat pulses: 46 (80%) exhibited a progressive increase in the discharge frequency as a function of stimulus intensity, and the spontaneous activity of two (4%) was inhibited. One population of cortical nociceptive neurons possessed restricted, contralateral receptive fields. These cells encoded the intensity of noxious mechanical and thermal stimulation. Sensitization of primary afferent nociceptors was reflected in the responses of SI cortical nociceptive neurons when the ascending series of noxious thermal stimulation was repeated. The population of cortical nociceptive neurons with restricted receptive fields exhibited no adaptation in the response during noxious heat pulses of 47 and 50 degrees C. At higher temperatures the response often continued to increase during the stimulus. The other population of cortical nociceptive neurons was found to have restricted, low-threshold receptive fields on the contralateral hindlimb and, in addition, could be activated only by intense pinching or noxious thermal stimuli delivered on any portion of the body. The stimulus-response functions obtained from noxious thermal stimulation of the contralateral hindlimb were not different from cortical nociceptive neurons with small receptive fields. However, nociceptive neurons with large receptive fields exhibited a consistent adaptation during a noxious heat pulse of 47 and 50 degrees C. Based on the response characteristics of these two populations of cortical nociceptive neurons, we conclude that neurons with small receptive fields possess the ability to provide information about the localization, the intensity, and the temporal attributes of a noxious stimulus.4+.

Responses of neurons in and near the thalamic ventrobasal complex of the rat to stimulation of uterus, cervix, vagina, colon, and skin

1993 ◽  
Vol 69 (2) ◽  
pp. 557-568 ◽  
Author(s):  
K. J. Berkley ◽  
G. Guilbaud ◽  
J. M. Benoist ◽  
M. Gautron
Keyword(s):  
Receptive Fields ◽  
The Body ◽  
Female Rats ◽  
Caudal Part ◽  
Response Characteristics ◽  
The Core ◽  
Ventrobasal Complex ◽  
Gentle Pressure ◽  
Somatic Receptive Fields ◽  
Stimulation Of

1. Previous studies in the rat and other species have shown that neurons in and near the ventrobasal complex (VB) can be activated by various visceral as well as somatic stimuli. 2. This study examined the responses of 84 single neurons in and near the rostral 2/3 of VB in 19 adult female rats in estrus to mechanical stimulation of the skin (brush, pressure, noxious pinch) and 4 different visceral stimuli, as follows: distension of both uterine horns, mechanical probing of the vagina, gentle pressure against the cervix, and distension of the colon. The rats were studied while under moderate gaseous anesthesia (33% O2-67% N2O + 0.5% halothane) and paralyzed (pancuronium bromide). 3. Of 77 neurons tested with both somatic and visceral stimuli, 70 were responsive to one type and/or the other. Responses to somatic stimuli were immediate with brief afterdischarges to the pinch stimuli. In contrast, responses to visceral stimuli were delayed an average of 9 s with long afterdischarges averaging 2 min. Most viscerally responsive neurons (74%) had somatic receptive fields, often (44%) to noxious pinch. 4. Of the 70 responsive neurons, 43 (61%) responded to 1 or more of the 4 visceral stimuli, primarily with excitation. Most of these 43 neurons (71%) were responsive to uterine distension, whereas fewer responded to stimulation of the cervix (45%), vagina (29%), or colon (34%). 5. Viscerally responsive neurons were preferentially located in regions bordering or near VB. Only 6 of 22 neurons within the core of VB (27%) responded to visceral stimuli, in contrast with 37 of 48 neurons bordering or near VB (77%). 6. The six viscerally responsive neurons within VB all had somatic receptive fields located primarily on the caudal part of the body and were responsive to only one or two of the four visceral stimuli, usually the uterus. The 37 viscerally responsive neurons bordering or near VB were of 3 types. Neurons of the first type (n = 15) were scattered throughout the areas bordering VB and responded to both somatic and visceral stimuli much like VB neurons, except that they showed more visceral convergence. Neurons of the second type (n = 11) were concentrated at the rostral and dorsal borders of VB and responded only to visceral stimuli, mainly the uterus. Neurons of the third type (n = 11) were concentrated ventrally and had very complex, long-lasting and history-dependent response characteristics to both visceral and somatic stimuli.(ABSTRACT TRUNCATED AT 400 WORDS)

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