Neuronal activity in cortical motor areas related to ipsilateral, contralateral, and bilateral digit movements of the monkey

1988 ◽  
Vol 60 (1) ◽  
pp. 325-343 ◽  
Author(s):  
J. Tanji ◽  
K. Okano ◽  
K. C. Sato
Keyword(s):  
Motor Cortex ◽  
Neuronal Activity ◽  
Primary Motor Cortex ◽  
Cell Activity ◽  
Left Hand ◽  
Hand Muscles ◽  
Cortical Motor ◽  
Key Press ◽  
The Right ◽  
Induced Changes

1. Single cell activity was studied in the precentral (PCM), premotor (PM), and supplementary (SMA) motor cortex of the monkey to compare magnitudes of activity changes in relation to ipsilateral, contralateral, and bilateral digit movements. 2. Three Japanese monkeys were trained to press a small key with the right or left hand, or with both hands, in accordance with visual instruction signals given 2.6-5.4 s before a visual movement-trigger signal. Great care was taken to train the animal to use only the required part of the limb. As a result of extensive training, electromyographic (EMG) studies revealed that muscle activities before the key press were limited to the digit and hand muscles of the limb instructed to move. No overt increase or decrease in activity was detectable in the proximal limb or body muscles in relation to the key-press movements or instructions. 3. Even though the movement was thus limited to distal forelimb, distinct ipsilateral relationships were observed in 8.2% of the task-related PCM neurons. They changed their activity before ipsilateral and bilateral (but not before contralateral) key press. 4. A majority of the neurons recorded from the digit area of PCM (mostly limited to the anterior bank of the central sulcus) exhibited a contralateral relationship; namely the activity increased or decreased before the onset of the contralateral and bilateral key-press movements. In most of them, the magnitudes of the activity changes before the contralateral and bilateral movements were similar. 5. In proximal limb and trunk areas of PCM and also in the somatosensory cortex, no neurons were found to exhibit distinct relations to any of the key-press movements. 6. In both SMA and PM, a number of neurons exhibited relationships of the type never or only rarely observed in the primary motor cortex. Thirty-seven percent of SMA and 62% of PM neurons exhibited premovement activity changes before all of the key-press movements. The movement-specific type of activity was observed in 28% of SMA and 16% of PM neurons. In these neurons, the activity changes were observed in relation to only one of the right or left key-press movements or exclusively in relation to the bilateral key press. Neuronal activity resembling the majority of the PCM neurons (contralateral type) was observed in 31% of SMA and 13% of PM neurons. 7. Instruction-induced changes in activity were more often found in the secondary than in the primary motor area.(ABSTRACT TRUNCATED AT 400 WORDS)

Laterality of Movement-Related Activity Reflects Transformation of Coordinates in Ventral Premotor Cortex and Primary Motor Cortex of Monkeys

2007 ◽  
Vol 98 (4) ◽  
pp. 2008-2021 ◽  
Author(s):  
Kiyoshi Kurata
Keyword(s):  
Motor Cortex ◽  
Neuronal Activity ◽  
Primary Motor Cortex ◽  
Premotor Cortex ◽  
Visuomotor Transformation ◽  
Related Activity ◽  
Reaching Task ◽  
Ventral Premotor Cortex ◽  
Cortical Motor ◽  
Target Locations

The ventral premotor cortex (PMv) and the primary motor cortex (MI) of monkeys participate in various sensorimotor integrations, such as the transformation of coordinates from visual to motor space, because the areas contain movement-related neuronal activity reflecting either visual or motor space. In addition to relationship to visual and motor space, laterality of the activity could indicate stages in the visuomotor transformation. Thus we examined laterality and relationship to visual and motor space of movement-related neuronal activity in the PMv and MI of monkeys performing a fast-reaching task with the left or right arm, toward targets with visual and motor coordinates that had been dissociated by shift prisms. We determined laterality of each activity quantitatively and classified it into four types: activity that consistently depended on target locations in either head-centered visual coordinates (V-type) or motor coordinates (M-type) and those that had either differential or nondifferential activity for both coordinates (B- and N-types). A majority of M-type neurons in the areas had preferences for reaching movements with the arm contralateral to the hemisphere where neuronal activity was recorded. In contrast, most of the V-type neurons were recorded in the PMv and exhibited less laterality than the M-type. The B- and N-types were recorded in the PMv and MI and exhibited intermediate properties between the V- and M-types when laterality and correlations to visual and motor space of them were jointly examined. These results suggest that the cortical motor areas contribute to the transformation of coordinates to generate final motor commands.

Motor Cortex Activation Induced by a Mirror: Evidence From Lateralized Readiness Potentials

2008 ◽  
Vol 100 (1) ◽  
pp. 19-23 ◽  
Author(s):  
Pascale Touzalin-Chretien ◽  
André Dufour
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Evoked Responses ◽  
Contralateral Hemisphere ◽  
Left Hand ◽  
Cortical Motor ◽  
Opposite Hand ◽  
Readiness Potentials ◽  
Similar Motor ◽  
Electrophysiological Correlate

Similar motor regions are activated during voluntarily executed or observed movements. We investigated whether observing movements of one's own hand through a mirror will generate activations in the cortical motor regions of both the moving and nonmoving hands. Using the lateralized readiness potential (LRP), an electrophysiological correlate of premotor activation in the primary motor cortex, we recorded evoked responses to movements while subjects were viewing the performing (right) hand through a mirror placed sagittally, giving the impression that the left hand was performing the task. Reliable LRPs were recorded in relation to the seen hand, indicating motor cortex activity in the contralateral hemisphere of the inactive hand while the opposite hand was performing the movement.

Neuronal activity in the primate premotor, supplementary, and precentral motor cortex during visually guided and internally determined sequential movements

1991 ◽  
Vol 66 (3) ◽  
pp. 705-718 ◽  
Author(s):  
H. Mushiake ◽  
M. Inase ◽  
J. Tanji
Keyword(s):  
Motor Cortex ◽  
Neuronal Activity ◽  
Primary Motor Cortex ◽  
Premotor Cortex ◽  
Cell Activity ◽  
Motor Task ◽  
Delay Period ◽  
Visual Signal ◽  
Visually Guided ◽  
Transitional Phase

1. Single-cell activity was recorded from three different motor areas in the cerebral cortex: the primary motor cortex (MI), supplementary motor area (SMA), and premotor cortex (PM). 2. Three monkeys (Macaca fuscata) were trained to perform a sequential motor task in two different conditions. In one condition (visually triggered task, VT), they reached to and touched three pads placed in a front panel by following lights illuminated individually from behind the pads. In the other condition (internally guided task, IT), they had to remember a predetermined sequence and press the three pads without visual guidance. In a transitional phase between the two conditions, the animals learned to memorize the correct sequence. Auditory instruction signals (tones of different frequencies) told the animal which mode it was in. After the instruction signals, the animals waited for a visual signal that triggered the first movement. 3. Neuronal activity was analyzed during three defined periods: delay period, premovement period, and movement period. Statistical comparisons were made to detect differences between the two behavioral modes with respect to the activity in each period. 4. Most, if not all, of MI neurons exhibited similar activity during the delay, premovement, and movement periods, regardless of whether the sequential motor task was visually guided or internally determined. 5. More than one-half of the SMA neurons were preferentially or exclusively active in relation to IT during both the premovement (55%) and movement (65%) periods. In contrast, PM neurons were more active (55% and 64% during the premovement and movement periods) in VT. 6. During the instructed-delay period, a majority of SMA neurons exhibited preferential or exclusive relation to IT whereas the activity in PM neurons was observed equally in different modes. 7. Two types of neurons exhibiting properties of special interest were observed. Sequence-specific neurons (active in a particular sequence only) were more common in SMA, whereas transition-specific neurons (active only at the transitional phase) were more common in PM. 8. Although a strict functional dichotomy is not acceptable, these observations support a hypothesis that the SMA is more related to IT, whereas PM is more involved in VT. 9. Some indications pointing to a functional subdivision of PM are obtained.

Involvement of the Primary Motor Cortex in Controlling Movements Executed with the Ipsilateral Hand Differs between Left- and Right-handers

2011 ◽  
Vol 23 (11) ◽  
pp. 3456-3469 ◽  
Author(s):  
Femke E. van den Berg ◽  
Stephan P. Swinnen ◽  
Nicole Wenderoth
Keyword(s):  
Motor Cortex ◽  
Left Hemisphere ◽  
Primary Motor Cortex ◽  
Movement Control ◽  
Motor Tasks ◽  
Left Hand ◽  
Left Handed ◽  
Virtual Lesion ◽  
Left And Right ◽  
The Right

Unimanual motor tasks, specifically movements that are complex or require high forces, activate not only the contralateral primary motor cortex (M1) but evoke also ipsilateral M1 activity. This involvement of ipsilateral M1 is asymmetric, such that the left M1 is more involved in motor control with the left hand than the right M1 in movements with the right hand. This suggests that the left hemisphere is specialized for movement control of either hand, although previous experiments tested mostly right-handed participants. In contrast, research on hemispheric asymmetries of ipsilateral M1 involvement in left-handed participants is relatively scarce. In the present study, left- and right-handed participants performed complex unimanual movements, whereas TMS was used to disrupt the activity of ipsilateral M1 in accordance with a “virtual lesion” approach. For right-handed participants, more disruptions were induced when TMS was applied over the dominant (left) M1. For left-handed participants, two subgroups could be distinguished, such that one group showed more disruptions when TMS was applied over the nondominant (left) M1, whereas the other subgroup showed more disruptions when the dominant (right) M1 was stimulated. This indicates that functional asymmetries of M1 involvement during ipsilateral movements are influenced by both hand dominance as well as left hemisphere specialization. We propose that the functional asymmetries in ipsilateral M1 involvement during unimanual movements are primarily attributable to asymmetries in the higher-order areas, although the contribution of transcallosal pathways and ipsilateral projections cannot be completely ruled out.

scholarly journals Low frequency (0.5Hz) rTMS over the right (non-dominant) motor cortex does not affect ipsilateral hand performance in healthy humans

2008 ◽  
Vol 66 (3b) ◽  
pp. 636-640 ◽  
Author(s):  
Fernanda Weiler ◽  
Pedro Brandão ◽  
Jairo de Barros-Filho ◽  
Carlos Enrique Uribe ◽  
Valdir Filgueiras Pessoa ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Repetitive Transcranial Magnetic Stimulation ◽  
Hand Function ◽  
Motor Task ◽  
Low Frequency ◽  
Left Hand ◽  
Healthy Humans ◽  
Hand Performance ◽  
The Right

Reduction of excitability of the dominant primary motor cortex (M1) improves ipsilateral hand function in healthy subjects. In analogy, inhibition of non-dominant M1 should also improve ipsilateral performance. In order to investigate this hypothesis, we have used slow repetitive transcranial magnetic stimulation (rTMS) and the Purdue Pegboard test. Twenty-eight volunteers underwent 10 minutes of either 0.5Hz rTMS over right M1 or sham rTMS (coil perpendicular to scalp). The motor task was performed before, immediately after, and 20 minutes after rTMS. In both groups, motor performance improved significantly throughout the sessions. rTMS inhibition of the non-dominant M1 had no significant influence over ipsilateral or contralateral manual dexterity, even though the results were limited by unequal performance between groups at baseline. This is in contrast to an improvement in left hand function previously described following slow rTMS over left M1, and suggests a less prominent physiological transcallosal inhibition from right to left M1.

scholarly journals Reduced Interhemispheric Coherence in Cerebellar Kainic Acid-Induced Lateralized Dystonia

2020 ◽  
Vol 11 ◽  
Author(s):  
Elena Laura Georgescu Margarint ◽  
Ioana Antoaneta Georgescu ◽  
Carmen Denise Mihaela Zahiu ◽  
Stefan-Alexandru Tirlea ◽  
Alexandru Rǎzvan Şteopoaie ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Kainic Acid ◽  
Primary Motor Cortex ◽  
Low Frequency ◽  
Muscular Activity ◽  
Cerebellar Hemisphere ◽  
Interhemispheric Coherence ◽  
General Locomotor Activity ◽  
Complex Circuits ◽  
The Right

The execution of voluntary muscular activity is controlled by the primary motor cortex, together with the cerebellum and basal ganglia. The synchronization of neural activity in the intracortical network is crucial for the regulation of movements. In certain motor diseases, such as dystonia, this synchrony can be altered in any node of the cerebello-cortical network. Questions remain about how the cerebellum influences the motor cortex and interhemispheric communication. This research aims to study the interhemispheric cortical communication between the motor cortices during dystonia, a neurological movement syndrome consisting of sustained or repetitive involuntary muscle contractions. We pharmacologically induced lateralized dystonia to adult male albino mice by administering low doses of kainic acid on the left cerebellar hemisphere. Using electrocorticography and electromyography, we investigated the power spectral densities, cortico-muscular, and interhemispheric coherence between the right and left motor cortices, before and during dystonia, for five consecutive days. Mice displayed lateralized abnormal motor signs, a reduced general locomotor activity, and a high score of dystonia. The results showed a progressive interhemispheric coherence decrease in low-frequency bands (delta, theta, beta) during the first 3 days. The cortico-muscular coherence of the affected side had a significant increase in gamma bands on days 3 and 4. In conclusion, lateralized cerebellar dysfunction during dystonia was associated with a loss of connectivity in the motor cortices, suggesting a possible cortical compensation to the initial disturbances induced by cerebellar left hemisphere kainate activation by blocking the propagation of abnormal oscillations to the healthy hemisphere. However, the cerebellum is part of several overly complex circuits, therefore other mechanisms can still be involved in this phenomenon.

scholarly journals Comparison of repeated transcranial stimulation and transcranial direct-current stimulation on primary motor cortex excitability and inhibition: A pilot study

2018 ◽  
pp. 59-67 ◽  
Author(s):  
Vincent Cabibel ◽  
Makii Muthalib ◽  
Jérôme Froger ◽  
Stéphane Perrey
Keyword(s):  
Pilot Study ◽  
Motor Cortex ◽  
Direct Current ◽  
Transcranial Direct Current Stimulation ◽  
Primary Motor Cortex ◽  
Motor Evoked Potentials ◽  
High Definition ◽  
Direct Current Stimulation ◽  
Motor Cortex Excitability ◽  
The Right

Repeated transcranial magnetic stimulation (rTMS) is a well-known clinical neuromodulation technique, but transcranial direct-current stimulation (tDCS) is rapidly growing interest for neurorehabilitation applications. Both methods (contralesional hemisphere inhibitory low-frequency: LF-rTMS or lesional hemisphere excitatory anodal: a-tDCS) have been employed to modify the interhemispheric imbalance following stroke. The aim of this pilot study was to compare aHD-tDCS (anodal high-definition tDCS) of the left M1 (2 mA, 20 min) and LF-rTMS of the right M1 (1 Hz, 20 min) to enhance excitability and reduce inhibition of the left primary motor cortex (M1) in five healthy subjects. Single-pulse TMS was used to elicit resting and active (low level muscle contraction, 5% of maximal electromyographic signal) motor-evoked potentials (MEPs) and cortical silent periods (CSPs) from the right and left extensor carpi radialis muscles at Baseline, immediately and 20 min (Post-Stim-20) after the end of each stimulation protocol. LF-rTMS or aHD-tDCS significantly increased right M1 resting and active MEP amplitude at Post-Stim-20 without any CSP modulation and with no difference between methods. In conclusion, this pilot study reported unexpected M1 excitability changes, which most likely stems from variability, which is a major concern in the field to consider.

Neuronal Clusters in the Primate Motor Cortex during Interceptin of Moving Targets.

2001 ◽  
Vol 13 (3) ◽  
pp. 319-331 ◽  
Author(s):  
Daeyeol Lee ◽  
Nicholas L. Port ◽  
Wolfgang Kruse ◽  
Apostolos P. Georgopoulos
Keyword(s):  
Motor Cortex ◽  
Rhesus Monkeys ◽  
Primary Motor Cortex ◽  
Human Subjects ◽  
Cell Activity ◽  
Target Velocity ◽  
Behavioral Strategies ◽  
Additional Information ◽  
Single Cell Activity ◽  
Initial Target

Two rhesus monkeys were trained to intercept a moving target at a fixed location with a feedback cursor controlled bya 2-D manipulandum. The direction from which the target appeared, the time from the target onset to its arrival at the interception point, and the target acceleration were randomized for each trial, thus requiring the animal to adjust its movement according to the visual input on a trail-by-trail basis. The two animals adopted different strategies, similar to those identified previously in human subjects. Single-cell activity was recorded from the arm area of the primary motor cortex in these two animals, and the neurons were classified based on the temporal patterns in their activity, using a nonhierarchical cluster analysis. Results of this analysis revealed differences in the complexity and diversity of motor cortical activity between the two animals that paralleled those of behavioral strategies. Most clusters displayed activity closedly related to the kinematics of hand movements. In addition, some clusters displayed patterns of activation that conveyed additional information necessary for successful performance of the task, such as the initial target velocity and the interval between successive submovements, suggesting that such information is represented in selective subpopulations of neurons in the primary motor cortex. These results also suggest that conversion of information about target motion into movement-related signals takes place in a broad network of cortical areas including the primary motor cortex.

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