Cerebral cortical representation of reflexive and volitional swallowing in humans

2001 ◽  
Vol 280 (3) ◽  
pp. G354-G360 ◽  
Author(s):  
Mark K. Kern ◽  
Safwan Jaradeh ◽  
Ronald C. Arndorfer ◽  
Reza Shaker
Keyword(s):  
Motor Cortex ◽  
Right Hemisphere ◽  
Imaging Technique ◽  
Cortical Representation ◽  
Sensory Motor ◽  
Multiple Regions ◽  
Motor Region ◽  
Cortical Regions ◽  
The Right ◽  
Insular Region

The purpose of this study was to compare cerebral cortical representation of experimentally induced reflexive swallow with that of volitional swallow. Eight asymptomatic adults (24–27 yr) were studied by a single-trial functional magnetic resonance imaging technique. Reflexive swallowing showed bilateral activity concentrated to the primary sensory/motor regions. Volitional swallowing was represented bilaterally in the insula, prefrontal, cingulate, and parietooccipital regions in addition to the primary sensory/motor cortex. Intrasubject comparison showed that the total volume of activity during volitional swallowing was significantly larger than that activated during reflexive swallows in either hemisphere ( P < 0.001). For volitional swallowing, the primary sensory/motor region contained the largest and the insular region the smallest volumes of activation in both hemispheres, and the total activated volume in the right hemisphere was significantly larger compared with the left ( P < 0.05). Intersubject comparison showed significant variability in the volume of activity in each of the four volitional swallowing cortical regions. We conclude that reflexive swallow is represented in the primary sensory/motor cortex and that volitional swallow is represented in multiple regions, including the primary sensory/motor cortex, insular, prefrontal/cingulate gyrus, and cuneus and precuneus region. Non-sensory/motor regions activated during volitional swallow may represent swallow-related intent and planning and possibly urge.

scholarly journals The Right Hemisphere Is Responsible for the Greatest Differences in Human Brain Response to High-Arousing Emotional versus Neutral Stimuli: A MEG Study

2021 ◽  
Vol 11 (8) ◽  
pp. 960
Author(s):  
Mina Kheirkhah ◽  
Philipp Baumbach ◽  
Lutz Leistritz ◽  
Otto W. Witte ◽  
Martin Walter ◽  
...  
Keyword(s):  
Human Brain ◽  
Right Hemisphere ◽  
Emotional Stimuli ◽  
Brain Response ◽  
Whole Brain ◽  
Brain Responses ◽  
Cortical Regions ◽  
The Right ◽  
Healthy Participants

Studies investigating human brain response to emotional stimuli—particularly high-arousing versus neutral stimuli—have obtained inconsistent results. The present study was the first to combine magnetoencephalography (MEG) with the bootstrapping method to examine the whole brain and identify the cortical regions involved in this differential response. Seventeen healthy participants (11 females, aged 19 to 33 years; mean age, 26.9 years) were presented with high-arousing emotional (pleasant and unpleasant) and neutral pictures, and their brain responses were measured using MEG. When random resampling bootstrapping was performed for each participant, the greatest differences between high-arousing emotional and neutral stimuli during M300 (270–320 ms) were found to occur in the right temporo-parietal region. This finding was observed in response to both pleasant and unpleasant stimuli. The results, which may be more robust than previous studies because of bootstrapping and examination of the whole brain, reinforce the essential role of the right hemisphere in emotion processing.

scholarly journals Asymmetric TDP pathology in primary progressive aphasia with right hemisphere language dominance

Neurology ◽  
2018 ◽  
Vol 90 (5) ◽  
pp. e396-e403 ◽  
Author(s):  
Garam Kim ◽  
Shahrooz Vahedi ◽  
Tamar Gefen ◽  
Sandra Weintraub ◽  
Eileen H. Bigio ◽  
...  
Keyword(s):  
Right Hemisphere ◽  
Primary Progressive Aphasia ◽  
Cortical Atrophy ◽  
Progressive Aphasia ◽  
Language Dominance ◽  
Primary Progressive ◽  
Activated Microglia ◽  
Unbiased Stereology ◽  
Cortical Regions ◽  
The Right

ObjectiveTo quantitatively examine the regional densities and hemispheric distribution of the 43-kDa transactive response DNA-binding protein (TDP-43) inclusions, neurons, and activated microglia in a left-handed patient with right hemisphere language dominance and logopenic-variant primary progressive aphasia (PPA).MethodsPhosphorylated TDP-43 inclusions, neurons, and activated microglia were visualized with immunohistochemical and histologic methods. Markers were quantified bilaterally with unbiased stereology in language- and memory-related cortical regions.ResultsClinical MRI indicated cortical atrophy in the right hemisphere, mostly in the temporal lobe. Significantly higher densities of TDP-43 inclusions were present in right language-related temporal regions compared to the left or to other right hemisphere regions. The memory-related entorhinal cortex (ERC) and language regions without significant atrophy showed no asymmetry. Activated microglia displayed extensive asymmetry (R > L). A substantial density of neurons remained in all areas and showed no hemispheric asymmetry. However, perikaryal size was significantly smaller in the right hemisphere across all regions except the ERC. To demonstrate the specificity of this finding, sizes of residual neurons were measured in a right-handed case with PPA and were found to be smaller in the language-dominant left hemisphere.ConclusionsThe distribution of TDP-43 inclusions and microglial activation in right temporal language regions showed concordance with anatomic distribution of cortical atrophy and clinical presentation. The results revealed no direct relationship between density of TDP-43 inclusions and activated microglia. Reduced size of the remaining neurons is likely to contribute to cortical atrophy detected by MRI. These findings support the conclusion that there is no obligatory relationship between logopenic PPA and Alzheimer pathology.

Impairments in Prehension Produced by Early Postnatal Sensory Motor Cortex Activity Blockade

2000 ◽  
Vol 83 (2) ◽  
pp. 895-906 ◽  
Author(s):  
John H. Martin ◽  
Laura Donarummo ◽  
Antony Hacking
Keyword(s):  
Motor Cortex ◽  
Motor Behavior ◽  
Lateral Position ◽  
Postnatal Life ◽  
Contralateral Limb ◽  
Early Postnatal Development ◽  
End Point ◽  
Sensory Motor ◽  
Impaired Limb ◽  
The Right

This study examined the effects of blocking neural activity in sensory motor cortex during early postnatal development on prehension. We infused muscimol, either unilaterally or bilaterally, into the sensory motor cortex of cats to block activity continuously between postnatal weeks 3–7. After stopping infusion, we trained animals to reach and grasp a cube of meat and tested behavior thereafter. Animals that had not received muscimol infusion (unilateral saline infusion; age-matched) reached for the meat accurately with small end-point errors. They grasped the meat using coordinated digit flexion followed by forearm supination on 82.7% of trials. Performance using either limb did not differ significantly. In animals receiving unilateral muscimol infusion, reaching and grasping using the limb ipsilateral to the infusion were similar to controls. The limb contralateral to infusion showed significant increases in systematic and variable reaching end-point errors, often requiring subsequent corrective movements to contact the meat. Grasping occurred on only 14.8% of trials, replaced on most trials by raking without distal movements. Compensatory adjustments in reach length and angle, to maintain end-point accuracy as movements were started from a more lateral position, were less effective using the contralateral limb than ipsilateral limb. With bilateral inactivations, the form of reaching and grasping impairments was identical to that produced by unilateral inactivation, but the magnitude of the reaching impairments was less. We discuss these results in terms of the differential effects of unilateral and bilateral inactivation on corticospinal tract development. We also investigated the degree to which these prehension impairments after unilateral blockade reflect control by each hemisphere. In animals that had received unilateral blockade between postnatal weeks (PWs) 3 and 7, we silenced on-going activity (after PW 11) during task performance using continuous muscimol infusion. We inactivated the right (previously active) and then the left (previously silenced) sensory motor cortex. Inactivation of the ipsilateral (right) sensory motor cortex produced a further increase in systematic error and less frequent normal grasping. Reinactivation of the contralateral (left) cortex produced larger increases in reaching and grasping impairments than those produced by ipsilateral inactivation. This suggests that the impaired limb receives bilateral sensory motor cortex control but that control by the contralateral (initially silenced) cortex predominates. Our data are consistent with the hypothesis that the normal development of skilled motor behavior requires activity in sensory motor cortex during early postnatal life.

scholarly journals Re-emergence of hand-muscle representations in human motor cortex after hand allograft

2009 ◽  
Vol 106 (17) ◽  
pp. 7197-7202 ◽  
Author(s):  
Claudia D. Vargas ◽  
Antoine Aballéa ◽  
Érika C. Rodrigues ◽  
Karen T. Reilly ◽  
Catherine Mercier ◽  
...  
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Motor Cortex ◽  
Upper Limb ◽  
Magnetic Stimulation ◽  
Cortical Representation ◽  
Human Motor Cortex ◽  
Hand Muscles ◽  
Right Hand ◽  
Hand Muscle ◽  
The Right

The human primary motor cortex (M1) undergoes considerable reorganization in response to traumatic upper limb amputation. The representations of the preserved arm muscles expand, invading portions of M1 previously dedicated to the hand, suggesting that former hand neurons are reassigned to the control of remaining proximal upper limb muscles. Hand allograft offers a unique opportunity to study the reversibility of such long-term cortical changes. We used transcranial magnetic stimulation in patient LB, who underwent bilateral hand transplantation 3 years after a traumatic amputation, to longitudinally track both the emergence of intrinsic (from the donor) hand muscles in M1 as well as changes in the representation of stump (upper arm and forearm) muscles. The same muscles were also mapped in patient CD, the first bilateral hand allograft recipient. Newly transplanted intrinsic muscles acquired a cortical representation in LB's M1 at 10 months postgraft for the left hand and at 26 months for the right hand. The appearance of a cortical representation of transplanted hand muscles in M1 coincided with the shrinkage of stump muscle representations for the left but not for the right side. In patient CD, transcranial magnetic stimulation performed at 51 months postgraft revealed a complete set of intrinsic hand-muscle representations for the left but not the right hand. Our findings show that newly transplanted muscles can be recognized and integrated into the patient's motor cortex.

Stop and Go: The Neural Basis of Selective Movement Prevention

2009 ◽  
Vol 21 (6) ◽  
pp. 1193-1203 ◽  
Author(s):  
James P. Coxon ◽  
Cathy M. Stinear ◽  
Winston D. Byblow
Keyword(s):  
Motor Cortex ◽  
Right Hemisphere ◽  
Inferior Frontal Gyrus ◽  
Middle Finger ◽  
Neural Basis ◽  
Movement Initiation ◽  
Stop And Go ◽  
Inferior Parietal Cortex ◽  
Supplementary Motor Cortex ◽  
The Right

Converging lines of evidence show that volitional movement prevention depends on the right prefrontal cortex (PFC), especially the right inferior frontal gyrus (IFG). Selective movement prevention refers to the rapid prevention of some, but not all, movement. It is unknown whether the IFG, or other prefrontal areas, are engaged when movement must be selectively prevented, and whether additional cortical areas are recruited. We used rapid event-related fMRI to investigate selective and nonselective movement prevention during performance of a temporally demanding anticipatory task. Most trials involved simultaneous index and middle finger extension. Randomly interspersed trials required the prevention of one, or both, finger movements. Regions of the right hemisphere, including the IFG, were active for selective and nonselective movement prevention, with an overlap in the inferior parietal cortex and the middle frontal gyrus. Selective movement prevention caused a significant delay in movement initiation of the other digit. These trials were associated with activation of the medial frontal cortex. The results provide support for a right-hemisphere network that temporarily “brakes” all movement preparation. When movement is selectively prevented, the supplementary motor cortex (SMA/pre-SMA) may participate in conflict resolution and subsequent reshaping of excitatory drive to the motor cortex.

Cortical Representation of Swallowing: A Modified Dual Task Paradigm

2002 ◽  
Vol 94 (3) ◽  
pp. 1029-1040 ◽  
Author(s):  
Stephanie K. Daniels ◽  
David M. Corey ◽  
Cristen L. Barnes ◽  
Nikki M. Faucheaux ◽  
Daniel H. Priestly ◽  
...  
Keyword(s):  
Dual Task ◽  
Right Hemisphere ◽  
Index Finger ◽  
Finger Tapping ◽  
Left Index Finger ◽  
Cortical Representation ◽  
Word Repetition ◽  
Dual Task Paradigm ◽  
Left And Right ◽  
The Right

It is unclear whether the cortical representation of swallowing is lateralized to the left cerebral hemisphere, right hemisphere, or bilaterally represented. As dysphagia is common in acute stroke, it is important to elucidate swallowing lateralization to facilitate earlier detection of stroke patients who may be at greater risk for dysphagia and aspiration. In this study, a modified dual task paradigm was designed to study laterality of swallowing in a group of 14 healthy, young, right-handed, male adults. The subjects were studied at baseline and with interference. Baseline conditions, performed separately, were continuous swallowing, finger tapping using the right and left index fingers, and word repetition. Interference tasks, including tapping with the right index finger, tapping with the left index finger, and word repetition, were completed with and without swallowing. Finger-tapping rate was measured, and x-ray samples of the swallowing task were taped to measure swallowing rate and volume swallowed. At baseline, the rate of tapping the right index finger was significantly faster than that of the left index finger. There was a significant decline in the tapping rates of both left and right index fingers with swallowing interference. The volume per swallow was significantly reduced during the interfering language task of silent repetition. These results offer partial support for a bilateral representation of swallowing as well as suggest an important left hemispheric contribution to swallowing. However, it cannot be concluded that the left hemisphere is more important than the right, as a comparable right hemisphere task was not studied.

Ipsilateral Motor Cortex Activity During Unimanual Hand Movements Relates to Task Complexity

2005 ◽  
Vol 93 (3) ◽  
pp. 1209-1222 ◽  
Author(s):  
Timothy Verstynen ◽  
Jörn Diedrichsen ◽  
Neil Albert ◽  
Paul Aparicio ◽  
Richard B. Ivry
Keyword(s):  
Motor Cortex ◽  
Left Hemisphere ◽  
Time Course ◽  
Right Hemisphere ◽  
Task Complexity ◽  
Hand Movements ◽  
Left Hand ◽  
Sequential Structure ◽  
Single Finger ◽  
The Right

Functional imaging studies have revealed recruitment of ipsilateral motor areas during the production of sequential unimanual finger movements. This phenomenon is more prominent in the left hemisphere during left-hand movements than in the right hemisphere during right-hand movements. Here we investigate whether this lateralization pattern is related specifically to the sequential structure of the unimanual action or generalizes to other complex movements. Using event-related fMRI, we measured activation changes in the motor cortex during three types of unimanual movements: repetitions of a sequence of movements with multiple fingers, repetitive “chords” composed of three simultaneous key presses, and simple repetitive tapping movements with a single finger. During sequence and chord movements, strong ipsilateral activation was observed and was especially pronounced in the left hemisphere during left-hand movements. This pattern was evident for both right-handed and, to a lesser degree, left-handed individuals. Ipsilateral activation was less pronounced in the tapping condition. The site of ipsilateral activation was shifted laterally, ventrally, and anteriorly with respect to that observed during contralateral movements and the time course of activation implied a role in the execution rather than planning of the movement. A control experiment revealed that strong ipsilateral activity in left motor cortex is specific to complex movements and does not depend on the number of required muscles. These findings indicate a prominent role of left hemisphere in the execution of complex movements independent of the sequential nature of the task.

Transient Cortical Stimulation To Alter Swallowing Physiology

2010 ◽  
Vol 19 (1) ◽  
pp. 16-20
Author(s):  
Ianessa A. Humbert
Keyword(s):  
Older Adults ◽  
Motor Cortex ◽  
Neurogenic Dysphagia ◽  
Healthy Older Adults ◽  
Old Adults ◽  
Cortical Areas ◽  
Sensory Motor ◽  
Delayed Initiation ◽  
Motor Region

Abstract Older adults are disproportionately affected by swallowing impairment, or dysphagia, a condition that can lead to increased morbidity and death. Delayed initiation of swallowing is a common and devastating pathophysiology of neurogenic dysphagia, and also is experienced by healthy older adults, making functional swallowing less safe. It is still not known if differences in activation of the cortex (primary sensory motor region) are responsible for delays in swallowing initiation, or if it is the consequence of advancing age. The goals of this proposal are to understand the functional role of the primary sensory-motor cortex on swallowing initiation and to characterize the effect of aging on swallowing initiation with transient cortical disruption. The overall hypothesis is that transient disruption of the primary sensory-motor cortex will produce measurable delays in swallowing initiation in young and old adults, but older adults will have more pronounced deficits. This investigation will determine whether cortical areas are involved in initiating swallowing as well as the importance of timing on this function.

Functional reorganization oF the primary motor cortex in a patient with a large arteriovenous malFormation involving the precentral gyrus

2013 ◽  
Vol 4 (2) ◽  
Author(s):  
Milan Radoš ◽  
Ines Nikić ◽  
Marko Radoš ◽  
Ivica Kostović ◽  
Patrick Hof ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Right Hemisphere ◽  
Motor Area ◽  
Lower Limbs ◽  
Motor Deficits ◽  
Precentral Gyrus ◽  
Functional Reorganization ◽  
The Right ◽  
The Brain

AbstractIt is known that the brain can compensate for deficits induced by acquired and developmental lesions through functional reorganization of the remaining parenchyma. Arteriovenous malformations (AVM) usually appear prenatally before a functional regional organization of the brain is fully established and patients generally do not present with motor deficits even when the AVM is located in the primary motor area indicating the redistribution of functions in cortical areas that are not pathologically altered. Here we present reorganization of the motor cortex in a patient with a large AVM involving most of the left parietal lobe and the paramedian part of the left precentral gyrus that is responsible for controlling the muscles of the lower limbs. Functional MRI showed that movements of both the right and left feet activated only the primary motor cortex in the right hemisphere, while there was no activation in the left motor cortex. This suggests that complete ipsilateral control over the movements of the right foot had been established in this patient. A reconstruction of the corticospinal tract using diffusion tensor imaging showed a near-complete absence of corticospinal fibers from the part of the left precentral gyrus affected by the AVM. From this clinical presentation it can be concluded that full compensation of motor deficits had occurred by redistributing function to the corresponding motor area of the contralateral

scholarly journals Brain Substrates for Distinct Spatial Processing Components Contributing to Hemineglect in Humans

2021 ◽  
Vol 11 (12) ◽  
pp. 1584
Author(s):  
Yann Cojan ◽  
Arnaud Saj ◽  
Patrik Vuilleumier
Keyword(s):  
Visual Search ◽  
Visual Memory ◽  
Right Hemisphere ◽  
Critical Role ◽  
Frontal Lobes ◽  
Spatial Processing ◽  
Spatial Tasks ◽  
Lesion Symptom Mapping ◽  
Cortical Regions ◽  
The Right

Several cortical and sub-cortical regions in the right hemisphere, particularly in the parietal and frontal lobes, but also in the temporal lobe and thalamus, are part of neural networks critically implicated in spatial and attentional functions. Damage to different sites within these networks can cause hemispatial neglect. The aim of this study was to identify the neural substrates of different spatial processing components that are known to contribute to neglect symptoms. Firstly, three different spatial tasks (visual search, bisection, and visual memory) were tested in 26 healthy controls. The fMRI results showed a differential activation of regions in the parietal and frontal lobes during bisection and visual search, respectively. Secondly, fMRI was used in 27 patients with focal right brain damage. Voxel-based lesion–symptom mapping was used to determine the relationships between specific sites of damage and the severity of deficits in these three spatial tasks. In the patients, we confirmed a critical role of the right lateral parietal cortex in bisection, but lesions in the frontal and temporal lobes were critical for visual search. These data support the existence of distinct components in spatial attentional processes that might be damaged to different degrees in neglect patients.

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