Activity of identified wrist-related pallidal neurons during step and ramp wrist movements in the monkey

1990 ◽  
Vol 64 (6) ◽  
pp. 1892-1906 ◽  
Author(s):  
I. Hamada ◽  
M. R. DeLong ◽  
N. Mano
Keyword(s):  
Peak Velocity ◽  
Wrist Joint ◽  
Discharge Rate ◽  
Body Parts ◽  
Wrist Flexion ◽  
Wrist Movement ◽  
Joint Rotation ◽  
Somatosensory Stimulation ◽  
Temporal Coupling ◽  
Movement Type

1. The activity of globus pallidus (GP) neurons (n = 1,117) was studied in two monkeys to reexamine the relation of neuronal activity to movement type (slow vs. fast) while they performed both a visually guided step and ramp wrist tracking task. To select neurons specifically related to wrist movements, we employed both a somatosensory examination of individual body parts and a statistical analysis of the strength of temporal coupling of neuronal discharges to active wrist movement. 2. Neuronal responses to somatosensory stimulation were studied in 1,000 high-frequency GP neurons, of which 686 exhibited clear responses to manipulation of body parts. Of the latter, 336 responded to passive manipulation of forelimb joints and 58 selectively to passive flexion or extension of the wrist. 3. In the external segment of GP (GPe), most neurons responding to passive wrist movement were found to be clustered in four to five adjacent, closely positioned (separated by 200 microns) tracks in single coronal planes. The clusters were irregular in shape with a maximal width of 800-1,000 microns. Separate clusters of neurons responsive to passive wrist movement were identified in planes 3 mm apart in one monkey and in planes 500 microns apart in the other. Multiple clusters of neurons were also found for neurons responsive to joints other than the wrist. These findings suggest a more discrete and complex representation of individual joints in the primate GP than previously conceived. 4. During the performance of the wrist flexion and extension task, 92 neurons showed clear and consistent changes in activity. For these neurons we measured, with a statistical method on a trial-by-trial basis, the strength of temporal coupling between the onset of active wrist movement and the onset of change in neuronal discharge rate. Fifteen neurons showed changes in activity time-locked to the onset of active wrist movement. 5. Twelve pallidal neurons were classified as “wrist-related” based on their movement-locked changes in discharge during task performance and their clear responses to passive wrist joint rotation on examination. All of these neurons exhibited statistically significant modulation of their discharge rate during both fast (peak velocity 97–205 degrees/s) and slow (peak velocity 20–62 degrees/s) wrist movements in the task. The amplitudes of modulation were larger during fast wrist movement than slow movement. These results suggest that the basal ganglia motor circuit plays a similar, rather than an exclusive, role in the control of slow and fast limb movements.

Activity of precentral neurons during torque-triggered hand movements in awake primates

1979 ◽  
Vol 57 (2) ◽  
pp. 174-184 ◽  
Author(s):  
Y. C. Wong ◽  
H. C. Kwan ◽  
J. T. Murphy
Keyword(s):  
Wrist Joint ◽  
Wrist Flexion ◽  
Somatosensory Stimulation ◽  
Sensory Stimuli ◽  
Neuronal Populations ◽  
Supportive Role ◽  
Flexion Extension ◽  
Cortical Responses ◽  
Early Portion ◽  
Temporally Correlated

In monkeys performing a handle-repositioning task involving primarily wrist flexion–extension (F–E) movements after a torque perturbation was delivered to the handle, single units were recorded extracellularly in the contralateral precentral cortex. Precentral neurons were identified by passive somatosensory stimulation, and were classified into five somatotopically organized populations. Based on electromyographic recordings, it was observed that flexors and extensors about the wrist joint were specifically involved in the repositioning of the handle, while many other muscles which act at the wrist and other forelimb joints were involved in the task in a supportive role. In precentral cortex, all neuronal responses observed were temporally correlated to both the sensory stimuli and the motor responses. Visual stimuli, presented simultaneously with torque perturbations, did not affect the early portion of cortical responses to such torque perturbations. In each of the five somatotopically organized neuronal populations, task-related neurons as well as task-unrelated ones were observed. A significantly larger proportion of wrist (F–E) neurons was related to the task, as compared with the other, nonwrist (F–E) populations. The above findings were discussed in the context of a hypothesis for the function of precentral cortex during voluntary limb movement in awake primates. This hypothesis incorporates a relationship between activities of populations of precentral neurons, defined with respect to their responses to peripheral events at or about single joints, and movements about the same joint.

The primate subthalamic nucleus. I. Functional properties in intact animals

1994 ◽  
Vol 72 (2) ◽  
pp. 494-506 ◽  
Author(s):  
T. Wichmann ◽  
H. Bergman ◽  
M. R. DeLong
Keyword(s):  
Basal Ganglia ◽  
Subthalamic Nucleus ◽  
Current Model ◽  
Body Parts ◽  
Movement Onset ◽  
Joint Rotation ◽  
Somatosensory Stimulation ◽  
Train Duration ◽  
Key Aspects ◽  
Passive Movements

1. The present study tests several key aspects of the current model of the intrinsic circuitry of the basal ganglia, in particular the degree to which basal ganglia-thalamocortical circuits are functionally segregated at the level of the subthalamic nucleus (STN). To this end the responses of STN cells to somatosensory examination (n = 301 cells), the polarity and latencies of neuronal responses to passive and active movements (n = 223 cells), responses to microstimulation (n = 1589 sites), and cross-correlation functions of pairs of neighboring neurons (n = 72 pairs) were studied in STNs of three African green monkeys. 2. The activity of 55% of cells examined in STN was briskly modulated in response to passive movements of individual contralateral body parts. Of these, 86% responded to passive joint rotation of muscle palpation, but in some cases (25% of responding cells) responses were also elicited by light touch. In 91% of the responding cells responses were elicited by manipulations around a single joint only. 3. The caudoventral sector in STN was largely devoid of cells with responses to somatosensory stimulation. Within the rostrodorsal zone a lateral region containing neurons that responded to arm movements and a more medial region with neurons responding to leg movement were found. Cells responding to orofacial movements were located more dorsally and rostrally. Neurons with similar responses to active and passive movements of the limbs tended to be clustered within “arm” and “leg” zones. 4. Of identified arm cells in STN (n = 80), 36% responded to the application of torque pulses to the elbow (43 responses overall). Forty-eight percent of these cells responded to both extension and flexion torques. Ninety-three percent of the responses were initial increases in discharge, which characteristically occurred earlier and were shorter than initial decreases. Fifty-three percent of the responses were biphasic or multiphasic. 5. During active step tracking movements 40% of STN arm cells (n = 53 cells) responded with significant changes in activity. Thirty-six percent of these cells showed responses with both extension and flexion movements. Of the responses, 90% were increases in discharge. Only 14% of all responses were biphasic or multiphasic. Responses tended to occur around the time of movement onset (average latency 2 ms after movement onset). 6. Microstimulation (bipolar pulses, 40 microA, 200–500 ms train duration, 400 Hz) of the core of STN itself did not appear to produce movement.4+ synchronized activity in only 11% of pairs.(ABSTRACT TRUNCATED AT 400 WORDS)

Signs of muscle thixotropy during human ballistic wrist joint movements

2005 ◽  
Vol 99 (5) ◽  
pp. 1922-1929 ◽  
Author(s):  
H. W. Axelson
Keyword(s):  
Reaction Time ◽  
Peak Velocity ◽  
Wrist Joint ◽  
Movement Time ◽  
Surface Emg ◽  
Motor Reaction ◽  
Wrist Flexion ◽  
Electromechanical Delay ◽  
Motor Reaction Time ◽  
Ballistic Movements

A study was conducted on healthy subjects to determine whether voluntary ballistic wrist flexion movements are influenced by immediately preceding conditioning of the forearm muscles. Single rapid wrist flexion movements were made in response to an auditory “Go” signal. Rectified surface EMG was recorded from wrist flexors and extensors, and joint position was measured by a goniometer. The movements were preceded (2–3 s) by four different conditioning routines: 40-s rest (Rest), 10-s voluntary alternating wrist joint flexion and extension movements (Osc), and 10 s of 25° weak isometric wrist extensor (Ext) or flexor contractions (Flex). When subjects made ballistic movements after Osc compared with Rest, peak velocity was higher ( P = 0.02) and movement time shorter ( P = 0.06), but there was no difference ( P = 0.83) in motor reaction time (time between the onset of the first agonist burst and movement onset). If the movements were preceded by Ext compared with Flex, motor reaction time was longer ( P = 0.01), indicating a longer electromechanical delay. There were no indications that postconditioning differences in agonist or antagonist muscle activity could explain the results. It was also demonstrated that, after Rest, peak velocity was lower ( P < 0.01) for the first than for the second of a series of repetitive ballistic movements. The observations corresponded to results from passive experiments in which the median nerve was electrically stimulated. In conclusion, history-dependent (thixotropic) changes in skeletal muscle resistance seem to have implications for voluntary ballistic wrist movements. The study also provided evidence that muscle conditioning influences the central nervous reaction time preceding ballistic contractions.

Neural activity in the monkey anterior ventrolateral thalamus during trained, ballistic movements

1993 ◽  
Vol 70 (6) ◽  
pp. 2276-2288 ◽  
Author(s):  
L. M. Forlano ◽  
M. K. Horne ◽  
E. G. Butler ◽  
D. Finkelstein
Keyword(s):  
Neural Activity ◽  
Wrist Joint ◽  
Discharge Rate ◽  
Activity Patterns ◽  
Afferent Input ◽  
Sustained Response ◽  
Movement Direction ◽  
Active Movement ◽  
Body Parts ◽  
Hold Period

1. To examine the role of the anterior ventrolateral thalamic nucleus (VLa) in motor control, extracellular single-cell recordings were made from the VLa nucleus in three conscious monkeys performing visually triggered, rapid movements requiring flexion and extension of the wrist joint. The movement paradigms consisted of three components: an initial hold period, a ballistic movement, and a final hold period. 2. Cerebellar nuclear stimulation was used to physiologically identify thalamic neurons receiving input from the cerebellum. Neurons subsequently confirmed histologically as lying within the VLa nucleus were located anterior to those “driven” by cerebellar stimulation. 3. The activities of 261 VLa neurons displaying movement-related behavior were examined. In the absence of movement, the activity of these neurons ranged from 5 to 80 spikes/s, the majority of cells (222/261; 85%) firing between 10 and 30 spikes/s. Neural activity was not influenced by afferent input from skin, joint, or muscle but altered markedly when the animal engaged in active movement. 4. The relationship between neural activity and movement at a specific joint was determined in 189 of the 261 neurons. The majority of these neurons (161/189; 85%) modulated their activity in response to movement confined to a single joint; the remaining neurons displayed multijoint motor responses, their activity being best related to a motor act, such as grasping, reaching, or feeding. There was no clear segregation in the representation of body parts in the VLa nucleus to suggest the presence of clearly defined somatotopy. 5. The activities of wrist-related neurons (45 of the 261) were examined to determine the motor characteristics of the VLa nucleus. Three distinctive activity patterns were exhibited by these neurons during the performance of the movement paradigms: 1) a phasic burst of < 300 ms in duration (34/45; 76%); 2) a sustained change in neural activity lasting > 300 ms (typically up to 1,000 ms; 4/45; 9%); and 3) both a phasic and a sustained response, the sustained response occurring either prior or subsequent to the phasic response (7/45; 15%). 6. The movement-related activity of the wrist-related neurons occurred late, 52% firing after the onset of the forearm electromyogram (EMG). In 47% of the neurons, discharge rate was related to movement direction and, in a smaller proportion (13%), joint position. No relationship was found between neural activity patterns and amplitude of movement or velocity of movement. (ABSTRACT TRUNCATED AT 400 WORDS)

Gustatory neural coding in the monkey cortex: stimulus intensity

1991 ◽  
Vol 65 (1) ◽  
pp. 76-86 ◽  
Author(s):  
T. R. Scott ◽  
C. R. Plata-Salaman ◽  
V. L. Smith ◽  
B. K. Giza
Keyword(s):  
Neural Coding ◽  
Discharge Rate ◽  
Taste Intensity ◽  
Response Functions ◽  
Somatosensory Stimulation ◽  
Gustatory Cortex ◽  
Intensity Response ◽  
Taste Cells ◽  
The Mean ◽  
Gustatory Neurons

1. We analyzed the activity of single neurons in gustatory cortex of alert cynomolgus monkeys in response to a range of stimulus intensities. Chemicals were deionized water, fruit juice, and several concentrations of the four prototypical taste stimuli: 10(-3)-1.0 M glucose, 10(-3)-1.0 M NaCl, 10(-4)-3 x 10(-2) M HCl, and 10(-5)-3 x 10(-3) M quinine HCl. 2. Taste-evoked responses could be recorded from a cortical gustatory area that measured 2.5 mm in its anteroposterior extent, 6.0 mm dorsoventrally, and 3.0 mm mediolaterally. Taste-responsive cells constituted 62 (3.7%) of the 1,661 neurons tested. Nongustatory cells gave responses associated with mouth movement (10.1%), somatosensory stimulation (2.2%), and approach or anticipation (0.9%). 3. Intensity-response functions were determined across 62 gustatory neurons. Neural thresholds for each stimulus quality conformed well to human psychophysical thresholds. Mean discharge rate was a direct function of stimulus concentration for glucose, NaCl, and quinine HCl. The most effective of the basic stimuli was glucose. 4. Power function exponents were calculated from the responses of neural subgroups most responsive to each basic stimulus. Those for glucose, NaCl, and quinine were within the range of psychophysically derived values. Thus the perceived intensity of each basic quality is presumably based on the activity of the appropriate neural subgroup rather than on the mean activity of all taste cells. 5. The mean breadth-of-tuning (entropy) coefficient for 62 gustatory neurons was 0.65 (range, 0.00–0.98). 6. There was no clear evidence of chemotopic organization in the gustatory cortex. 7. An analysis of taste quality indicated that sweet stimuli evoked patterns of activity that were clearly distinct from those of the nonsweet chemicals. Among the latter group, NaCl was differentiable from HCl and quinine HCl, whose patterns were closely related. 8. The response characteristics of cortical taste cells imply gustatory thresholds and intensity-response functions for the nonhuman primate that conform well to those reported in psychophysical studies of humans, reinforcing the value of this neural model for human taste intensity perception.

Three-dimensional kinematics of the lunate, hamate, capitate and triquetrum with type 1 or 2 lunate morphology

2017 ◽  
Vol 43 (4) ◽  
pp. 380-386 ◽  
Author(s):  
Shingo Abe ◽  
Hisao Moritomo ◽  
Kunihiro Oka ◽  
Kazuomi Sugamoto ◽  
Kenji Kasubuchi ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Wrist Joint ◽  
Three Dimensional ◽  
Wrist Flexion ◽  
Ulnar Deviation ◽  
Dart Throwing ◽  
Carpal Kinematics ◽  
Throwing Motion

The purpose of this study was to investigate the differences in three-dimensional carpal kinematics between type 1 and 2 lunates. We studied 15 instances of wrist flexion to extension (nine type 1, six type 2), 13 of radial to ulnar deviation (seven type 1, six type 2), and 12 of dart-throwing motion (six each of type 1 and 2) in 25 normal participants based on imaging with computerized tomography. Mean proximal translation of the distal articular midpoint of the triquetrum relative to type 2 lunates during wrist radioulnar deviation was 2.9 mm (standard deviation (SD) 0.7), which was significantly greater than for type 1 lunates, 1.6 mm (SD 0.6). The hamate contacted the lunate in ulnar deviation and ulnar flexion of wrists with type 2 lunates but not with type 1. We conclude that the four-corner kinematics of the wrist joint are different between type 1 and 2 lunates.

Activity of Ventroposterior Thalamus Neurons During Rotation and Translation in the Horizontal Plane in the Alert Squirrel Monkey

2008 ◽  
Vol 99 (5) ◽  
pp. 2533-2545 ◽  
Author(s):  
Vladimir Marlinski ◽  
Robert A. McCrea
Keyword(s):  
Horizontal Plane ◽  
Peak Velocity ◽  
Discharge Rate ◽  
Stimulus Frequency ◽  
Squirrel Monkeys ◽  
Response Amplitude ◽  
Whole Body ◽  
Power Functions ◽  
Stimulus Velocity ◽  
Rotational Response

The firing behavior of 107 vestibular-sensitive neurons in the ventroposterior thalamus was studied in two alert squirrel monkeys during whole body rotation and translation in the horizontal plane. Vestibular-sensitive neurons were distributed primarily along the anterior and posterior borders of ventroposterior nuclei; three clusters of these neurons could be distinguished based on their location and inputs. Eighty-four neurons responded to rotation; 66 (78%) of them responded to rotation only and 18 (22%) to both rotation and translation. Forty-one neurons were sensitive to linear translation; 23 (56%) of them responded to translation only. The population rotational response to 0.5-Hz sinusoids with a peak velocity of 40°/s showed a gain of 0.23 ± 0.15 spike·s−1·deg−1·s−1 and phase lagging behind the angular velocity by −9.3 ± 34.1°. Although rotational response amplitude increased with the stimulus velocity across the range 4–100°/s, the rotational sensitivity decreased with and was inversely proportional to the stimulus velocity. The rotational response amplitude and sensitivity increased with the stimulus frequency across the range 0.2–4.0 Hz. The population response to sinusoidal translation at 0.5 Hz and 0.1 g amplitude had a gain of 111.3 ± 53.7 spikes·s−1· g−1 and lagged behind stimulus acceleration by −71.9 ± 42.6°. Translational sensitivity decreased as acceleration increased and this was inversely proportional to the square root of the acceleration. Results of this study imply that changes in the discharge rate of vestibular-sensitive thalamic neurons can be approximated using power functions of the angular and linear velocity of spatial motion.

Cerebellar nuclear cell activity during antagonist cocontraction and reciprocal inhibition of forearm muscles

1985 ◽  
Vol 54 (2) ◽  
pp. 231-244 ◽  
Author(s):  
R. Wetts ◽  
J. F. Kalaska ◽  
A. M. Smith
Keyword(s):  
Activity Patterns ◽  
Cell Activity ◽  
Reciprocal Inhibition ◽  
Discharge Frequency ◽  
Wrist Flexion ◽  
Wrist Movement ◽  
Forearm Muscles ◽  
Flexion Extension ◽  
Nuclear Cell ◽  
Low Order

Monkeys were trained to exert a maintained isometric pinch with the thumb and forefinger. This task reliably elicited a simultaneous cocontraction of the forearm muscles. The same monkeys were also taught to insert the open hand into a manipulandum, flex and extend the wrist 35 and 15 degrees, respectively, and maintain an isometric wrist position against a mechanical stop for 1 s. This second task comprised two conditions: a dynamic or movement phase and a static or isometric phase. Movement always involved a wrist displacement of 50 degrees. Although some forearm muscles demonstrated bidirectional activity during the wrist displacement phase, all the wrist and finger muscles were alternatively active in isometric flexion or extension. Of the neurons in the dentate and interposed nuclei that consistently changed discharge during repeated isometric prehension, over 90% (61/67) of the neurons increased activity during this cocontraction of forearm muscles. About 70% (47/67) of these same nuclear cells discharged with a reciprocal pattern of firing during alternating wrist flexion-extension movements. Forty-six neurons had sustained and reciprocal discharge during the maintained isometric wrist postures. No differences were seen between the activity patterns of dentate and interposed cells with respect to either the prehension task or the reciprocal wrist-movement task. The discharge frequency of some dentate and interpositus neurons could be correlated with prehensile force as well as velocity of wrist movement and torque developed by wrist muscles. Correlation coefficients were calculated between nuclear cell discharge and the amplitude of the surface EMGs of the flexors and extensors of the wrist and fingers during the wrist-movement task. Sixteen nuclear cells showed low-order, but reliably positive, correlations with one of the two forearm muscle groups (mean r = 0.33). In contrast, a sample of seven Purkinje cells recorded during the same task demonstrated low-order correlations that were negative in sign (mean r = -0.30) between discharge frequency and one of the two forearm EMGs.

scholarly journals Carpal Tunnel Syndrome and its relation to dentist

2015 ◽  
Vol 27 (3) ◽  
Author(s):  
Nyoman Ayu Anggayanti ◽  
I Putu Gde Adiatmika
Keyword(s):  
Carpal Tunnel Syndrome ◽  
Musculoskeletal Disorders ◽  
Carpal Tunnel ◽  
Wrist Joint ◽  
Compressive Force ◽  
Incidence Rates ◽  
Wrist Flexion ◽  
Entrapment Neuropathies ◽  
Compressive Neuropathy ◽  
Tunnel Syndrome

Introduction: Carpal Tunnel Syndrome (CTS) is a compressive neuropathy, caused by mechanical distortion produced by a compressive force of the median nerve at the level of the wrist. Primary sign is pain in the wrist, tingling sensation, pain or numbness in thumb, index finger, middle finger, and radial side of the ring finger, also there is a reduction of the grip strength and function of the affected hand. This sign tend to be worse at night and clumsiness during the activities that requiring wrist flexion. This syndrome is well-known and frequent accounts for 90% of all entrapment neuropathies. Incidence rates up to 276:100.000 per year. More common in females than in males, its occurrence is commonly bilaterally with a peak age range of 40 to 60 years. This is the productive age, which is often reported that the Carpal Tunnel Syndrome are work-related musculoskeletal disorders caused by strain and repeated movements. Disscussion: Dentist are high risks to go through musculoskeletal disorders covering wrist joint. The condition may happen because of the dentist position while handling patients is not in ergonomic position. These include repetitive prolonged hand activities, forceful static posture of wrist, vibration, and localized mechanical stress. To reduce the symptoms of musculoskeletal disorders since the beginning, has developed an integrated concept of teamwork in a modern dental practice. This concept is known as the four-handed dentistry which consists of dentists and assistants with their respective skills. Conclusion: The four-handed treatment techniques has been developed that is now largely acceptable. The concept of four-handed dentistry is expected to prevent the movement that makes the muscles tense, especially in the area around the wrist. And may ultimately reduce the incidence of Carpal Tunnel Syndrome

scholarly journals Modified Osteotomy for Treatment of Forearm Deformities (Masada IIb) in Hereditary Multiple Osteochondromas: A Retrospective Review

2021 ◽  
Author(s):  
Ge Yan ◽  
Guoxin Nan
Keyword(s):  
Distraction Osteogenesis ◽  
External Fixator ◽  
Wrist Joint ◽  
Elbow Flexion ◽  
Wrist Flexion ◽  
Ilizarov External Fixator ◽  
Multiple Osteochondromas ◽  
Before And After ◽  
Ulnar Lengthening ◽  
Flexion And Extension

Abstract Purpose: Approximately 30% of patients with hereditary multiple osteochondromas (HMO) have forearm deformity and dysfunction. The aim of this retrospective study was to review our experience with the surgical treatment of children with HMO and Masada IIb forearm deformities.Methods: Data of eight children treated for HMO Masada IIb forearm deformity at our hospital between 2015 and 2019 were collected from the hospital records and retrospectively reviewed. All patients underwent ulnar lengthening by distraction osteogenesis using either the Orthofix or Ilizarov external fixator. Range of movements at the elbow and wrist joints, and forearm supination/pronation, before and after the operation were recorded. Radiographs were evaluated by the Fogel method, and wrist joint function by the Krimmer method.Results: Follow-up radiographs showed significant improvement in relative ulnar shortening after treatment (pre-operative 9.23 ± 5.21 mm; post-operative 0.33 ± 4.13 mm). Changes in radial articular angle (pre-operative 33.55° ± 3.88° to 32.78° ± 6.57°) and carpal slip (pre-operative 45.00% ± 19.09%; post-operative 43.13% ± 16.68%) were not significant. Elbow flexion and extension, wrist flexion and extension, ulnar and radial deviation at wrist, and forearm rotation were significantly improved after surgery. Wrist function was graded as excellent in seven patients and as good in one patient. One patient treated with the Ilizarov external fixator had poor radial head reduction.Conclusion: Ulnar lengthening with distraction osteogenesis is an effective treatment for HMO Masada IIb deformities. The optimum site for ulnar osteotomy appears to be at the proximal one-third to one-fourth of the ulna.

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