Functional Connectivity Between Secondary and Primary Motor Areas Underlying Hand–Foot Coordination

2007 ◽  
Vol 98 (1) ◽  
pp. 414-422 ◽  
Author(s):  
Winston D. Byblow ◽  
James P. Coxon ◽  
Cathy M. Stinear ◽  
Melanie K. Fleming ◽  
Garry Williams ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Motor Cortex ◽  
Muscle Activation ◽  
Primary Motor Cortex ◽  
Premotor Cortex ◽  
Hand Movement ◽  
Physiological Basis ◽  
Activation Conditions ◽  
Motor Representations ◽  
Motor Areas

Coincident hand and foot movements are more reliably performed in the same direction than in opposite directions. Using transcranial magnetic stimulation (TMS) to assess motor cortex function, we examined the physiological basis of these movements across three novel experiments. Experiment 1 demonstrated that upper limb corticomotor excitability changed in a way that facilitated isodirectional movements of the hand and foot, during phasic and isometric muscle activation conditions. Experiment 2 demonstrated that motor cortex inhibition was modified with active, but not passive, foot movement in a manner that facilitated hand movement in the direction of foot movement. Together, these findings demonstrate that the coupling between motor representations within motor cortex is activity dependent. Because there are no known connections between hand and foot areas within primary motor cortex, experiment 3 used a dual-coil paired-pulse TMS protocol to examine functional connectivity between secondary and primary motor areas during active ankle dorsiflexion and plantarflexion. Dorsal premotor cortex (PMd) and supplementary motor area (SMA) conditioning, but not ventral premotor cortex (PMv) conditioning, produced distinct phases of task-dependent modulation of excitability of forearm representations within primary motor cortex (M1). Networks involving PMd–M1 facilitate isodirectional movements of hand and foot, whereas networks involving SMA–M1 facilitate corticomotor pathways nonspecifically, which may help to stabilize posture during interlimb coordination. These results may have implications for targeted neurorehabilitation after stroke.

scholarly journals Shared functional connectivity between the dorso-medial and dorso-ventral streams in macaques

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
R. Stefan Greulich ◽  
Ramina Adam ◽  
Stefan Everling ◽  
Hansjörg Scherberger
Keyword(s):  
Functional Connectivity ◽  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Rhesus Macaques ◽  
Premotor Cortex ◽  
Network Connectivity ◽  
Insular Cortex ◽  
Resting State Fmri ◽  
Precentral Gyrus ◽  
Related Information

Abstract Manipulation of an object requires us to transport our hand towards the object (reach) and close our digits around that object (grasp). In current models, reach-related information is propagated in the dorso-medial stream from posterior parietal area V6A to medial intraparietal area, dorsal premotor cortex, and primary motor cortex. Grasp-related information is processed in the dorso-ventral stream from the anterior intraparietal area to ventral premotor cortex and the hand area of primary motor cortex. However, recent studies have cast doubt on the validity of this separation in separate processing streams. We investigated in 10 male rhesus macaques the whole-brain functional connectivity of these areas using resting state fMRI at 7-T. Although we found a clear separation between dorso-medial and dorso-ventral network connectivity in support of the two-stream hypothesis, we also found evidence of shared connectivity between these networks. The dorso-ventral network was distinctly correlated with high-order somatosensory areas and feeding related areas, whereas the dorso-medial network with visual areas and trunk/hindlimb motor areas. Shared connectivity was found in the superior frontal and precentral gyrus, central sulcus, intraparietal sulcus, precuneus, and insular cortex. These results suggest that while sensorimotor processing streams are functionally separated, they can access information through shared areas.

Facilitation From Ventral Premotor Cortex of Primary Motor Cortex Outputs to Macaque Hand Muscles

2003 ◽  
Vol 90 (2) ◽  
pp. 832-842 ◽  
Author(s):  
G. Cerri ◽  
H. Shimazu ◽  
M. A. Maier ◽  
R. N. Lemon
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Premotor Cortex ◽  
Macaque Monkey ◽  
Hand Muscles ◽  
Ventral Premotor Cortex ◽  
Cortex Area ◽  
Light Sedation ◽  
Cortical Inputs ◽  
Motor Representations

We demonstrate that in the macaque monkey there is robust, short-latency facilitation by ventral premotor cortex (area F5) of motor outputs from primary motor cortex (M1) to contralateral intrinsic hand muscles. Experiments were carried out on two adult macaques under light sedation (ketamine plus medetomidine HCl). Facilitation of hand muscle electromyograms (EMG) was tested using arrays of fine intracortical microwires implanted, respectively, in the wrist/digit motor representations of F5 and M1, which were identified by previous mapping with intracortical microstimulation. Single pulses (70–200 μA) delivered to F5 microwires never evoked any EMG responses, but small responses were occasionally seen with double pulses (interval: 3 ms) at high intensity. However, both single- and double-pulse stimulation of F5 could facilitate the EMG responses evoked from M1 by single shocks. The facilitation was large (up to 4-fold with single and 12-fold with double F5 shocks) and occurred with an early onset, with significant effects at intervals of only 1–2 ms between conditioning F5 and test M1 stimuli. A number of possible pathways could be responsible for these effects, although it is argued that the most likely mechanism would be the facilitation, by cortico-cortical inputs from F5, of corticospinal I wave activity evoked from M1. This facilitatory action could be of considerable importance for the coupling of grasp-related neurons in F5 and M1 during visuomotor tasks.

scholarly journals All Talk and No Action: A Transcranial Magnetic Stimulation Study of Motor Cortex Activation during Action Word Production

2004 ◽  
Vol 16 (3) ◽  
pp. 374-381 ◽  
Author(s):  
Massimiliano Oliveri ◽  
Chiara Finocchiaro ◽  
Kevin Shapiro ◽  
Massimo Gangitano ◽  
Alfonso Caramazza ◽  
...  
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Motor Cortex ◽  
Magnetic Stimulation ◽  
Primary Motor Cortex ◽  
Premotor Cortex ◽  
Brain Regions ◽  
Word Production ◽  
Grammatical Category ◽  
Paired Pulse ◽  
Motor Areas

A number of researchers have proposed that the premotor and motor areas are critical for the representation of words that refer to actions, but not objects. Recent evidence against this hypothesis indicates that the left premotor cortex is more sensitive to grammatical differences than to conceptual differences between words. However, it may still be the case that other anterior motor regions are engaged in processing a word's sensorimotor features. In the present study, we used singleand paired-pulse transcranial magnetic stimulation to test the hypothesis that left primary motor cortex is activated during the retrieval of words (nouns and verbs) associated with specific actions. We found that activation in the motor cortex increased for action words compared with non-action words, but was not sensitive to the grammatical category of the word being produced. These results complement previous findings and support the notion that producing a word activates some brain regions relevant to the sensorimotor properties associated with that word regardless of its grammatical category.

Multiple Nonprimary Motor Areas in the Human Cortex

1997 ◽  
Vol 77 (4) ◽  
pp. 2164-2174 ◽  
Author(s):  
Gereon R. Fink ◽  
Richard S. J. Frackowiak ◽  
Uwe Pietrzyk ◽  
Richard E. Passingham
Keyword(s):  
Motor Cortex ◽  
Somatosensory Cortex ◽  
Primary Motor Cortex ◽  
Premotor Cortex ◽  
Motor Area ◽  
Related Activity ◽  
Human Cortex ◽  
Premotor Area ◽  
Cingulate Motor Area ◽  
Motor Areas

Fink, Gereon R., Richard S. J. Frackowiak, Uwe Pietrzyk, and Richard E. Passingham. Multiple nonprimary motor areas in the human cortex. J. Neurophysiol. 77: 2164–2174, 1997. We measured the distribution of regional cerebral blood flow with positron emission tomography while three subjects moved their hand, shoulder, or leg. The images were coregistered with each individual's anatomic magnetic resonance scans. The data were analyzed for each individual to avoid intersubject averaging and so to preserve individual gyral anatomy. Instead of inspecting all pixels, we prospectively restricted the data analysis to particular areas of interest. These were defined on basis of the anatomic and physiological literature on nonhuman primates. By examining only a subset of areas, we strengthened the power of the statistical analysis and thereby increased the confidence in reporting single subject data. On the lateral convexity, motor related activity was found for all three subjects in the primary motor cortex, lateral premotor cortex, and an opercular area within the premotor cortex. In addition, there was activation of somatosensory cortex (SI), the supplementary somatosensory area (SII) in the Sylvian fissure, and parietal association areas (Brodmann areas 5 and 40). There was also activation in the insula. We suggest that the activation in the dorsal premotor cortex may correspond with dorsal premotor area (PMd) as described in the macaque brain. We propose three hypotheses as to the probable location of vental premotor area (PMv) in the human brain. On the medial surface, motor-related activity was found for all three subjects in the leg areas of the primary motor cortex and somatosensory cortex and also activity for the hand, shoulder, and leg in the supplementary motor area (SMA) on the dorsal medial convexity and in three areas in the cingulate sulcus. We suggest that the three cingulate areas may correspond with rostral cingulate premotor area, dorsal cingulate motor area (CMAd), and ventral cingulate motor area (CMAv) as identified in the macaque brain. Somatotopic mapping was demonstrated in the primary motor and primary somatosensory cortex. In all three subjects, the arm region lay anterior to the leg region in parietal area 5. Also in all three subjects, the arm region lay anterior to the leg region in the supplementary motor cortex.

scholarly journals Mapping Human Laryngeal Motor Cortex during Vocalization

2020 ◽  
Vol 30 (12) ◽  
pp. 6254-6269 ◽  
Author(s):  
Nicole Eichert ◽  
Daniel Papp ◽  
Rogier B Mars ◽  
Kate E Watkins
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Brain Activity ◽  
Premotor Cortex ◽  
Neural Representation ◽  
Functional Magnetic Resonance ◽  
Human Larynx ◽  
Motor Representations ◽  
Quantitative Neuroimaging ◽  
Hand Area

Abstract The representations of the articulators involved in human speech production are organized somatotopically in primary motor cortex. The neural representation of the larynx, however, remains debated. Both a dorsal and a ventral larynx representation have been previously described. It is unknown, however, whether both representations are located in primary motor cortex. Here, we mapped the motor representations of the human larynx using functional magnetic resonance imaging and characterized the cortical microstructure underlying the activated regions. We isolated brain activity related to laryngeal activity during vocalization while controlling for breathing. We also mapped the articulators (the lips and tongue) and the hand area. We found two separate activations during vocalization—a dorsal and a ventral larynx representation. Structural and quantitative neuroimaging revealed that myelin content and cortical thickness underlying the dorsal, but not the ventral larynx representation, are similar to those of other primary motor representations. This finding confirms that the dorsal larynx representation is located in primary motor cortex and that the ventral one is not. We further speculate that the location of the ventral larynx representation is in premotor cortex, as seen in other primates. It remains unclear, however, whether and how these two representations differentially contribute to laryngeal motor control.

scholarly journals Mapping human laryngeal motor cortex during vocalization

2020 ◽  
Author(s):  
Nicole Eichert ◽  
Daniel Papp ◽  
Rogier B. Mars ◽  
Kate E. Watkins
Keyword(s):  
Motor Control ◽  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Brain Activity ◽  
Premotor Cortex ◽  
Neural Representation ◽  
Human Larynx ◽  
Motor Representations ◽  
Quantitative Neuroimaging ◽  
Hand Area

AbstractThe representations of the articulators involved in human speech production are organized somatotopically in primary motor cortex. The neural representation of the larynx, however, remains debated. Both a dorsal and a ventral larynx representation have been previously described. It is unknown, however, whether both representations are located in primary motor cortex. Here, we mapped the motor representations of the human larynx using fMRI and characterized the cortical microstructure underlying the activated regions. We isolated brain activity related to laryngeal activity during vocalization while controlling for breathing. We also mapped the articulators (the lips and tongue) and the hand area. We found two separate activations during vocalization – a dorsal and a ventral larynx representation. Structural and quantitative neuroimaging revealed that myelin content and cortical thickness underlying the dorsal, but not the ventral larynx representation, are similar to those of other primary motor representations. This finding confirms that the dorsal larynx representation is located in primary motor cortex and that the ventral one is not. We further speculate that the location of the ventral larynx representation is in premotor cortex, as seen in other primates. It remains unclear, however, whether and how these two representations differentially contribute to laryngeal motor control.

Imagery of Voluntary Movement of Fingers, Toes, and Tongue Activates Corresponding Body-Part-Specific Motor Representations

2003 ◽  
Vol 90 (5) ◽  
pp. 3304-3316 ◽  
Author(s):  
H. Henrik Ehrsson ◽  
Stefan Geyer ◽  
Eiichi Naito
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Supplementary Motor Area ◽  
Premotor Cortex ◽  
Body Part ◽  
Cortical Activation ◽  
Motor Area ◽  
Cortex Area ◽  
Area 6 ◽  
Motor Areas

We investigate whether imagery of voluntary movements of different body parts activates somatotopical sections of the human motor cortices. We used functional magnetic resonance imaging to detect the cortical activity when 7 healthy subjects imagine performing repetitive (0.5-Hz) flexion/extension movements of the right fingers or right toes, or horizontal movements of the tongue. We also collected functional images when the subjects actually executed these movements and used these data to define somatotopical representations in the motor areas. In this study, we relate the functional activation maps to cytoarchitectural population maps of areas 4a, 4p, and 6 in the same standard anatomical space. The important novel findings are 1) that imagery of hand movements specifically activates the hand sections of the contralateral primary motor cortex (area 4a) and the contralateral dorsal premotor cortex (area 6) and a hand representation located in the caudal cingulate motor area and the most ventral part of the supplementary motor area; 2) that when imagining making foot movements, the foot zones of the posterior part of the contralateral supplementary motor area (area 6) and the contralateral primary motor cortex (area 4a) are active; and 3) that imagery of tongue movements activates the tongue region of the primary motor cortex and the premotor cortex bilaterally (areas 4a, 4p, and 6). These results demonstrate that imagery of action engages the somatotopically organized sections of the primary motor cortex in a systematic manner as well as activating some body-part-specific representations in the nonprimary motor areas. Thus the content of the mental motor image, in this case the body part, is reflected in the pattern of motor cortical activation.

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