Neuronal Activity in Motor Cortical Areas Reflects the Sequential Context of Movement

2004 ◽  
Vol 91 (4) ◽  
pp. 1748-1762 ◽  
Author(s):  
Yoram Ben-Shaul ◽  
Rotem Drori ◽  
Itay Asher ◽  
Eran Stark ◽  
Zoltan Nadasdy ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Neuronal Activity ◽  
Motor System ◽  
Single Neuron ◽  
Arm Movements ◽  
Movement Direction ◽  
Motor Execution ◽  
Movement Sequences ◽  
Cortical Areas ◽  
Motion Segment

Natural actions can be described as chains of simple elements, whereas individual motion elements are readily concatenated to generate countless movement sequences. Sequence-specific neurons have been described extensively, suggesting that the motor system may implement temporally complex motions by using such neurons to recruit lower-level movement neurons modularly. Here, we set out to investigate whether activity of movement-related neurons is independent of the sequential context of the motion. Two monkeys were trained to perform linear arm movements either individually or as components of double-segment motions. However, comparison of neuronal activity between these conditions is delicate because subtle kinematic variations generally occur within different contexts. We therefore used extensive procedures to identify the contribution of variations in motor execution to differences in neuronal activity. Yet, even after application of these procedures we find that neuronal activity in the motor cortex (PMd and M1) associated with a given motion segment differs between the two contexts. These differences appear during preparation and become even more prominent during motion execution. Interestingly, despite context-related differences on the single-neuron level, the population as a whole still allows a reliable readout of movement direction regardless of the sequential context. Thus the direction of a movement and the sequential context in which it is embedded may be simultaneously and reliably encoded by neurons in the motor cortex.

Neuronal activity in the claustrum of the monkey during performance of multiple movements

1996 ◽  
Vol 76 (3) ◽  
pp. 2115-2119 ◽  
Author(s):  
K. Shima ◽  
E. Hoshi ◽  
J. Tanji
Keyword(s):  
Motor Cortex ◽  
Neuronal Activity ◽  
Arm Movements ◽  
Visual Signals ◽  
Visually Guided ◽  
Motor Execution ◽  
Related Activity ◽  
Histological Confirmation ◽  
Selection Of ◽  
The Way

1. We studied neuronal activity in the claustrum of monkeys during performance of three different arm movements. We verified recording sites of claustral neurons by histological confirmation of microlesions. For the sake of comparison, we also recorded from the arm area of the precentral motor cortex (MI). Selection of the movements was either visually guided or determined by memorized information. 2. A striking property of claustral neurons is their nonselective relation to the three movements (push, pull, and turn a manipulandum). A vast majority (70%) of movement-related neurons exhibited increase of discharge in relation to all three movements, whereas only 16% were active in relation to one of the three movements. By contrast, about one-half of neurons in the MI were active in relation to a single movement. In both areas, the movement-related activity was similar regardless of whether the movements were selected by visual signals or by memory. 3. The study is the first to reveal involvement of claustral neurons in motor execution, and their activity property suggests that the way they are involved is different from that of MI neurons.

scholarly journals Neuronal Activity Related to the Visual Representation of Arm Movements in the Lateral Cerebellar Cortex

2003 ◽  
Vol 89 (3) ◽  
pp. 1223-1237 ◽  
Author(s):  
Xuguang Liu ◽  
Edwin Robertson ◽  
R. Christopher Miall
Keyword(s):  
Neuronal Activity ◽  
Cerebellar Cortex ◽  
Arm Movements ◽  
Arm Movement ◽  
Visual Outcome ◽  
Neural Representation ◽  
Movement Direction ◽  
Visually Guided ◽  
Motor Actions ◽  
Increased Activity

Testing the hypothesis that the lateral cerebellum forms a sensory representation of arm movements, we investigated cortical neuronal activity in two monkeys performing visually guided step-tracking movements with a manipulandum. A virtual target and cursor image were viewed co-planar with the manipulandum. In the normal task, manipulandum and cursor moved in the same direction; in the mirror task, the cursor was left-right reversed. In one monkey, 70- and 200-ms time delays were introduced on cursor movement. Significant task-related activity was recorded in 31 cells in one animal and 142 cells in the second: 10.2% increased activity before arm movements onset, 77.1% during arm movement, and 12.7% after the new position was reached. To test for neural representation of the visual outcome of movement, firing rate modulation was compared in normal and mirror step-tracking. Most task-related neurons (68%) showed no significant directional modulation. Of 70 directionally sensitive cells, almost one-half ( n = 34, 48%) modulated firing with a consistent cursor movement direction, many fewer responding to the manipulandum direction ( n = 9, 13%). For those “cursor-related” cells tested with delayed cursor movement, increased activity onset was time-locked to arm movement and not cursor movement, but activation duration was extended by an amount similar to the applied delay. Hence, activity returned to baseline about when the delayed cursor reached the target. We conclude that many cells in the lateral cerebellar cortex signaled the direction of cursor movement during active step-tracking. Such a predictive representation of the arm movement could be used in the guidance of visuo-motor actions.

Proprioceptive activity in primate primary somatosensory cortex during active arm reaching movements

1994 ◽  
Vol 72 (5) ◽  
pp. 2280-2301 ◽  
Author(s):  
M. J. Prud'homme ◽  
J. F. Kalaska
Keyword(s):  
Motor Cortex ◽  
Somatosensory Cortex ◽  
Parietal Cortex ◽  
Arm Movements ◽  
Reaching Movements ◽  
Movement Direction ◽  
Tonic Activity ◽  
Directional Tuning ◽  
Central Target ◽  
Tonic Response

1. We studied the activity of 254 cells in the primary somatosensory cortex (SI) responding to inputs from peripheral proprioceptors in a variety of tasks requiring active reaching movements of the contralateral arm. 2. The majority of cells with receptive fields on the proximal arm (shoulder and elbow) were broadly and unimodally tuned for movement direction, often with approximately sinusoidal tuning curves similar to those seen in motor and parietal cortex. 3. The predominant temporal response profiles were directionally tuned phasic bursts during movement and tonic activity that varied with different arm postures. 4. Most cells showed both phasic and tonic response components to differing degrees, and the population formed a continuum from purely phasic to purely tonic cells with no evidence of separate distinct phasic and tonic populations. This indicates that the initial cortical neuronal correlates of the introspectively distinguishable sensations of movement and position are represented in an overlapping or distributed manner in SI. 5. The directional tuning of the phasic and tonic response components of most cells was generally similar, although rarely identical. 6. We tested 62 cells during similar active and passive arm movements. Many cells showed large differences in their responses in the two conditions, presumably due to changes in peripheral receptor discharge during active muscle contractions. 7. We tested 86 cells in a convergent movement task in which monkeys made reaching movements to a single central target from eight peripheral starting positions. A majority of the cells (46 of 86, 53.5%) showed a movement direction-related hysteresis in which their tonic activity after movement to the central target varied with the direction by which the arm moved to the target. The directionality of this hysteresis was coupled with the movement-related directional tuning of the cells. 8. We recorded the discharge of 93 cells as the monkeys performed the task while compensating for loads in different directions. The large majority of cells showed a statistically significant modulation of activity as a function of load direction, which was qualitatively similar to that seen in motor cortex under similar task conditions. Quantitatively, however, the sensitivity of SI proprioceptive cells to loads was less than that seen in motor cortex but greater than in parietal cortex. 9. We interpret these results in terms of their implications for the central representation of the spatiotemporal form (“kinematics”) of arm movements and postures. Most importantly, the results emphasize the important influence of muscle contractile activity on the central proprioceptive representation of active movements.

A quantitative study of neuronal discharge in areas 5, 2, and 4 of the monkey during fast arm movements

1991 ◽  
Vol 66 (2) ◽  
pp. 429-443 ◽  
Author(s):  
P. Burbaud ◽  
C. Doegle ◽  
C. Gross ◽  
B. Bioulac
Keyword(s):  
Motor Cortex ◽  
Somatosensory Cortex ◽  
Functional Organization ◽  
Receptive Fields ◽  
Arm Movements ◽  
Burst Duration ◽  
Movement Direction ◽  
Neuron Activity ◽  
Movement Onset ◽  
Area 5

1. The properties of parietal neurons were studied in four adult rhesus monkeys during fast arm movements. The animals were trained to perform flexion or extension of the forearm about the elbow in response to specific auditory cues. Single neuron activity was recorded in 272 area 5 neurons, 81 neurons of the somatosensory cortex, and 92 neurons of the motor cortex. 2. In area 5, 42% of neuronal changes occurred before movement onset (early changes) and 58% after (late changes), with 21% before the earliest electromyogram. The range of modification in activity took place between 260 ms before movement onset and 180 ms after. Complex receptive fields were found in area 5 with a greater proportion among the late neurons (72%) than among the early neurons (32%). 3. Different patterns of activity were observed in neurons recorded in both movement directions. Reciprocal neurons represented 52% of the motor cortex neurons and 41% of the neurons in the somatosensory cortex but only 14% of the area 5 neurons. Of the remainder area 5 neurons, 46% were direction-sensitive neurons and 39% coactivated neurons. This suggests a more complex encoding of movement direction in area 5 than in area 2 or 4. 4. Temporal characteristics of the neuronal bursts were quantitatively analyzed in areas 5, 2, and 4. Neuronal burst duration was longer in area 5 than in the other areas. Above all, a variability of burst parameters, which did not depend on variable movement execution, was noticed in area 5. Therefore neuronal activity in this cortical area cannot be simply explained by a convergence of sensory and motor inputs but may depend on the behavioral context in which the movement is performed. 5. A correlation between neuronal burst duration and movement duration was found in 41% of area 2 neurons. In area 5, this correlation was observed in 20% of the late neurons and in 14% of the early neurons. A correlation between neuronal discharge frequency and movement velocity was found in 34% of area 2 neurons and 24% of area 4 neurons. About 16% of both late and early neurons in area 5 showed such a correlation. These neurons received polyarticular input, and it is suggested that they may be involved in the kinematic encoding of polyarticular movements. 6. A topographic and functional organization of area 5 was noticed. In anterior area, 5, 83% of the neurons had receptive fields and most of the reciprocal neurons and those exhibiting a correlation with movement parameters were found there.(ABSTRACT TRUNCATED AT 400 WORDS)

Reaching Movements With Similar Hand Paths but Different Arm Orientations. II. Activity of Individual Cells in Dorsal Premotor Cortex and Parietal Area 5

1997 ◽  
Vol 78 (5) ◽  
pp. 2413-2426 ◽  
Author(s):  
Stephen H. Scott ◽  
Lauren E. Sergio ◽  
John F. Kalaska
Keyword(s):  
Neuronal Activity ◽  
Premotor Cortex ◽  
Cell Activity ◽  
Reaching Movements ◽  
Movement Direction ◽  
Dorsal Premotor Cortex ◽  
Cortical Areas ◽  
Parietal Area ◽  
Area 5 ◽  
Interaction Term

Scott, Stephen H., Lauren E. Sergio, and John F. Kalaska. Reaching movements with similar hand paths but different arm orientations. II. Activity of individual cells in dorsal premotor cortex and parietal area 5. J. Neurophysiol. 78: 2413–2426, 1997. Neuronal activity in primary motor cortex (MI) is altered when monkeys make reaching movements along similar handpaths at shoulder level with two different arm orientations, either in the natural orientation with the elbow positioned below the level of the shoulder and hand or in an abducted orientation with the elbow abducted nearly to shoulder level. The present study examines to what degree two other cortical areas, the dorsal premotor (PMd) and parietal area 5, also show modulation of cell activity related to arm geometry during reaching. The activity of most (89%) of the 207 cells in PMd recorded while monkeys made reaching movements showed a statistically significant change in activity between orientations [analysis of variation (ANOVA), P < 0.01]. A common effect of arm orientation on cell activity was a change in the overall level of discharge either before, during, and/or after movement (67%, ANOVA, task main effect, P < 0.01). Many cells (76%) showed a statistical change in their response to movement direction (ANOVA, task × direction interaction term, P < 0.01), including changes in dynamic range and changes in the preferred direction of cells that were directionally tuned in both arm orientations. Overall, these effects were similar qualitatively but not as strong quantitatively as those observed in MI. A sample of cells was recorded in area 5 of one monkey. Most (95%) of the 79 area 5 cells showed a change in activity when reaching movements were performed using different arm orientations (ANOVA, P < 0.01). As in PMd and MI, many area 5 cells (56, 71%) showed changes in their tonic discharge before, during, and/or after movement, and 70 cells (89%) showed changes in their response to movement direction (ANOVA, task × direction interaction term, P < 0.01). The observed changes in neuronal activity related to posture and movement in MI, PMd and area 5 demonstrate that single-cell activity in these cortical areas is not simply related to the spatial attributes of hand trajectory but is also strongly influenced by attributes of movement related to arm geometry.

scholarly journals Persistent Motor System Abnormalities in Formerly Concussed Athletes

2011 ◽  
Vol 46 (3) ◽  
pp. 234-240 ◽  
Author(s):  
Louis De Beaumont ◽  
David Mongeon ◽  
Sébastien Tremblay ◽  
Julie Messier ◽  
François Prince ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Motor System ◽  
Silent Period ◽  
Intracortical Inhibition ◽  
Football Players ◽  
System Function ◽  
Motor Execution ◽  
Cortical Silent Period ◽  
Motor Cortex Excitability ◽  
Execution Speed

Context: The known detrimental effects of sport concussions on motor system function include balance problems, slowed motor execution, and abnormal motor cortex excitability. Objective: To assess whether these concussion-related alterations of motor system function are still evident in collegiate football players who sustained concussions but returned to competition more than 9 months before testing. Design: Case-control study. Setting: University laboratory. Patients or Other Participants: A group of 21 active, university-level football players who had experienced concussions was compared with 15 university football players who had not sustained concussions. Intervention(s): A force platform was used to assess center-of-pressure (COP) displacement and COP oscillation regularity (approximate entropy) as measures of postural stability in the upright position. A rapid alternating-movement task was also used to assess motor execution speed. Transcranial magnetic stimulation over the motor cortex was used to measure long-interval intracortical inhibition and the cortical silent period, presumably reflecting γ-aminobutyric acid subtype B receptor-mediated intracortical inhibition. Main Outcome Measure(s): COP displacement and oscillation regularity, motor execution speed, long-interval intracortical inhibition, cortical silent period. Results: Relative to controls, previously concussed athletes showed persistently lower COP oscillation randomness, normal performance on a rapid alternating-movement task, and more M1 intracortical inhibition that was related to the number of previous concussions. Conclusions: Sport concussions were associated with pervasive changes in postural control and more M1 intracortical inhibition, providing neurophysiologic and behavioral evidence of lasting, subclinical changes in motor system integrity in concussed athletes.

Focal Photothrombotic Lesion of the Rat Motor Cortex Increases BDNF Levels in Motor-Sensory Cortical Areas Not Accompanied by Recovery of Forelimb Motor Skills

2007 ◽  
Vol 24 (8) ◽  
pp. 1362-1377 ◽  
Author(s):  
Dorota Sulejczak ◽  
Ewelina Ziemlińska ◽  
Julita Czarkowska-Bauch ◽  
Ewa Nosecka ◽  
Ryszard Strzalkowski ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Motor Skills ◽  
Cortical Areas
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