Coherent neural representation of hand speed in humans revealed by MEG imaging

The spiking activity of single neurons in the primate motor cortex is correlated with various limb movement parameters, including velocity. Recent findings obtained using local field potentials suggest that hand speed may also be encoded in the summed activity of neuronal populations. At this macroscopic level, the motor cortex has also been shown to display synchronized rhythmic activity modulated by motor behavior. Yet whether and how neural oscillations might be related to limb speed control is still poorly understood. Here, we applied magnetoencephalography (MEG) source imaging to the ongoing brain activity in subjects performing a continuous visuomotor (VM) task. We used coherence and phase synchronization to investigate the coupling between the estimated activity throughout the brain and the simultaneously recorded instantaneous hand speed. We found significant phase locking between slow (2- to 5-Hz) oscillatory activity in the contralateral primary motor cortex and time-varying hand speed. In addition, we report long-range task-related coupling between primary motor cortex and multiple brain regions in the same frequency band. The detected large-scale VM network spans several cortical and subcortical areas, including structures of the frontoparietal circuit and the cerebello–thalamo–cortical pathway. These findings suggest a role for slow coherent oscillations in mediating neural representations of hand kinematics in humans and provide further support for the putative role of long-range neural synchronization in large-scale VM integration. Our findings are discussed in the context of corticomotor communication, distributed motor encoding, and possible implications for brain–machine interfaces.

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Long range high-gamma (60-90 Hz) coupling between primary motor cortex and SMA during motor control revealed by MEG source imaging

NeuroImage ◽

10.1016/s1053-8119(09)71874-9 ◽

2009 ◽

Vol 47 ◽

pp. S173

Author(s):

K Jerbi ◽

H Hui ◽

D Pantazis ◽

J-P Lachaux ◽

O Bertrand ◽

...

Keyword(s):

Motor Control ◽

Motor Cortex ◽

Long Range ◽

Primary Motor Cortex ◽

Source Imaging ◽

High Gamma

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Aging-Related Changes in Cortical Sources of Sleep Oscillatory Neural Activity Following Motor Learning Reflect Contributions of Cortical Thickness and Pre-sleep Functional Activity

Frontiers in Aging Neuroscience ◽

10.3389/fnagi.2021.787654 ◽

2022 ◽

Vol 13 ◽

Author(s):

Ahren B. Fitzroy ◽

Bethany J. Jones ◽

Kyle A. Kainec ◽

Jeehye Seo ◽

Rebecca M. C. Spencer

Keyword(s):

Older Adults ◽

Motor Cortex ◽

Motor Learning ◽

Cortical Thickness ◽

Neural Activity ◽

Primary Motor Cortex ◽

Supplementary Motor Area ◽

Brain Regions ◽

Theta Activity ◽

Oscillatory Activity

Oscillatory neural activity during sleep, such as that in the delta and sigma bands, is important for motor learning consolidation. This activity is reduced with typical aging, and this reduction may contribute to aging-related declines in motor learning consolidation. Evidence suggests that brain regions involved in motor learning contribute to oscillatory neural activity during subsequent sleep. However, aging-related differences in regional contributions to sleep oscillatory activity following motor learning are unclear. To characterize these differences, we estimated the cortical sources of consolidation-related oscillatory activity using individual anatomical information in young and older adults during non-rapid eye movement sleep after motor learning and analyzed them in light of cortical thickness and pre-sleep functional brain activation. High-density electroencephalogram was recorded from young and older adults during a midday nap, following completion of a functional magnetic resonance imaged serial reaction time task as part of a larger experimental protocol. Sleep delta activity was reduced with age in a left-weighted motor cortical network, including premotor cortex, primary motor cortex, supplementary motor area, and pre-supplementary motor area, as well as non-motor regions in parietal, temporal, occipital, and cingulate cortices. Sleep theta activity was reduced with age in a similar left-weighted motor network, and in non-motor prefrontal and middle cingulate regions. Sleep sigma activity was reduced with age in left primary motor cortex, in a non-motor right-weighted prefrontal-temporal network, and in cingulate regions. Cortical thinning mediated aging-related sigma reductions in lateral orbitofrontal cortex and frontal pole, and partially mediated delta reductions in parahippocampal, fusiform, and lingual gyri. Putamen, caudate, and inferior parietal cortex activation prior to sleep predicted frontal and motor cortical contributions to sleep delta and theta activity in an age-moderated fashion, reflecting negative relationships in young adults and positive or absent relationships in older adults. Overall, these results support the local sleep hypothesis that brain regions active during learning contribute to consolidation-related neural activity during subsequent sleep and demonstrate that sleep oscillatory activity in these regions is reduced with aging.

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Movement Decomposition in the Primary Motor Cortex

Cerebral Cortex ◽

10.1093/cercor/bhy060 ◽

2018 ◽

Vol 29 (4) ◽

pp. 1619-1633 ◽

Cited By ~ 6

Author(s):

Naama Kadmon Harpaz ◽

David Ungarish ◽

Nicholas G Hatsopoulos ◽

Tamar Flash

Keyword(s):

Motor Cortex ◽

Primary Motor Cortex ◽

Temporal Dynamics ◽

Single Cells ◽

Brain Regions ◽

Specific Pattern ◽

Neural Representation ◽

Neural Population ◽

Population Activity ◽

Acceleration And Deceleration

Abstract A complex action can be described as the composition of a set of elementary movements. While both kinematic and dynamic elements have been proposed to compose complex actions, the structure of movement decomposition and its neural representation remain unknown. Here, we examined movement decomposition by modeling the temporal dynamics of neural populations in the primary motor cortex of macaque monkeys performing forelimb reaching movements. Using a hidden Markov model, we found that global transitions in the neural population activity are associated with a consistent segmentation of the behavioral output into acceleration and deceleration epochs with directional selectivity. Single cells exhibited modulation of firing rates between the kinematic epochs, with abrupt changes in spiking activity timed with the identified transitions. These results reveal distinct encoding of acceleration and deceleration phases at the level of M1, and point to a specific pattern of movement decomposition that arises from the underlying neural activity. A similar approach can be used to probe the structure of movement decomposition in different brain regions, possibly controlling different temporal scales, to reveal the hierarchical structure of movement composition.

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Corticospinal Tract Microstructure Correlates With Beta Oscillatory Activity in the Primary Motor Cortex After Stroke

Stroke ◽

10.1161/strokeaha.121.034344 ◽

2021 ◽

Author(s):

Robert Schulz ◽

Marlene Bönstrup ◽

Stephanie Guder ◽

Jingchun Liu ◽

Benedikt Frey ◽

...

Keyword(s):

Motor Cortex ◽

Fractional Anisotropy ◽

Primary Motor Cortex ◽

Supplementary Motor Area ◽

Premotor Cortex ◽

Motor Impairment ◽

Motor Area ◽

Oscillatory Activity ◽

Premotor Area ◽

Beta Power

Background and Purpose: Cortical beta oscillations are reported to serve as robust measures of the integrity of the human motor system. Their alterations after stroke, such as reduced movement-related beta desynchronization in the primary motor cortex, have been repeatedly related to the level of impairment. However, there is only little data whether such measures of brain function might directly relate to structural brain changes after stroke. Methods: This multimodal study investigated 18 well-recovered patients with stroke (mean age 65 years, 12 males) by means of task-related EEG and diffusion-weighted structural MRI 3 months after stroke. Beta power at rest and movement-related beta desynchronization was assessed in 3 key motor areas of the ipsilesional hemisphere that are the primary motor cortex (M1), the ventral premotor area and the supplementary motor area. Template trajectories of corticospinal tracts (CST) originating from M1, premotor cortex, and supplementary motor area were used to quantify the microstructural state of CST subcomponents. Linear mixed-effects analyses were used to relate tract-related mean fractional anisotropy to EEG measures. Results: In the present cohort, we detected statistically significant reductions in ipsilesional CST fractional anisotropy but no alterations in EEG measures when compared with healthy controls. However, in patients with stroke, there was a significant association between both beta power at rest ( P =0.002) and movement-related beta desynchronization ( P =0.003) in M1 and fractional anisotropy of the CST specifically originating from M1. Similar structure-function relationships were neither evident for ventral premotor area and supplementary motor area, particularly with respect to their CST subcomponents originating from premotor cortex and supplementary motor area, in patients with stroke nor in controls. Conclusions: These data suggest there might be a link connecting microstructure of the CST originating from M1 pyramidal neurons and beta oscillatory activity, measures which have already been related to motor impairment in patients with stroke by previous reports.

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A novel approach for locating mice brain regions of Cryptococcus neoformans CNS invasion

Bangladesh Journal of Pharmacology ◽

10.3329/bjp.v11is1.26845 ◽

2016 ◽

Vol 11 ◽

pp. S136-S143

Author(s):

Chunting He ◽

Qingfen Chen ◽

Longkun Zhu

Keyword(s):

Motor Cortex ◽

Cryptococcus Neoformans ◽

Primary Motor Cortex ◽

Thalamic Nucleus ◽

Molecular Layer ◽

Brain Regions ◽

Dorsal Lateral Geniculate Nucleus ◽

Novel Approach ◽

Stratum Lucidum ◽

Lateral Posterior

Aim of this study was to locate the brain regions where Cryptococcus interact with brain cells and invade into brain. After 7 days of intratracheal inocula-tion of GFP-tagged Cryptococcus neoformans strains H99, serial cryosections (10 ?m) from 3 C57 BL/6 J mice brains were imaged with immunofluorescence microscopy. GFP-tagged H99 were found in some brain regions such as primary motor cortex-secondary motor cortex, caudate putamen, stratum lucidum of hippocampus, field CA1 of hippocampus, dorsal lateral geniculate nucleus, lateral posterior thalamic nucleus, laterorostral part, lateral posterior thalamic nucleus, mediorostral part, retrosplenial agranular cortex, lateral area of secondary visual cortex, and lacunosum molecular layer of the hippocampus. The results will be very useful for further exploring the mechanism of C. neoformans infection of brain.

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Effective intracortical microstimulation parameters applied to primary motor cortex for evoking forelimb movements to stable spatial end points

Journal of Neurophysiology ◽

10.1152/jn.00172.2012 ◽

2013 ◽

Vol 110 (5) ◽

pp. 1180-1189 ◽

Cited By ~ 14

Author(s):

Gustaf M. Van Acker ◽

Sommer L. Amundsen ◽

William G. Messamore ◽

Hongyu Y. Zhang ◽

Carl W. Luchies ◽

...

Keyword(s):

Motor Cortex ◽

Large Scale ◽

Primary Motor Cortex ◽

Emg Activity ◽

Intracortical Microstimulation ◽

End Points ◽

End Point ◽

Motor Effects ◽

Forelimb Movements ◽

Stimulation Of

High-frequency, long-duration intracortical microstimulation (HFLD-ICMS) applied to motor cortex is recognized as a useful and informative method for corticomotor mapping by evoking natural-appearing movements of the limb to consistent stable end-point positions. An important feature of these movements is that stimulation of a specific site in motor cortex evokes movement to the same spatial end point regardless of the starting position of the limb. The goal of this study was to delineate effective stimulus parameters for evoking forelimb movements to stable spatial end points from HFLD-ICMS applied to primary motor cortex (M1) in awake monkeys. We investigated stimulation of M1 as combinations of frequency (30–400 Hz), amplitude (30–200 μA), and duration (0.5–2 s) while concurrently recording electromyographic (EMG) activity from 24 forelimb muscles and movement kinematics with a motion capture system. Our results suggest a range of parameters (80–140 Hz, 80–140 μA, and 1,000-ms train duration) that are effective and safe for evoking forelimb translocation with subsequent stabilization at a spatial end point. The mean time for stimulation to elicit successful movement of the forelimb to a stable spatial end point was 475.8 ± 170.9 ms. Median successful frequency and amplitude were 110 Hz and 110 μA, respectively. Attenuated parameters resulted in inconsistent, truncated, or undetectable movements, while intensified parameters yielded no change to movement end points and increased potential for large-scale physiological spread and adverse focal motor effects. Establishing cortical stimulation parameters yielding consistent forelimb movements to stable spatial end points forms the basis for a systematic and comprehensive mapping of M1 in terms of evoked movements and associated muscle synergies. Additionally, the results increase our understanding of how the central nervous system may encode movement.

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Imaging of neural oscillations with embedded inferential and group prevalence statistics

10.1101/164731 ◽

2017 ◽

Author(s):

Peter W. Donhauser ◽

Esther Florin ◽

Sylvain Baillet

Keyword(s):

Brain Activity ◽

Signal Strength ◽

Brain Regions ◽

Oscillatory Activity ◽

Neural Oscillations ◽

Source Reconstruction ◽

Signal To Noise ◽

Source Imaging ◽

Methodological Challenges ◽

Oscillatory Power

AbstractMagnetoencephalography and electroencephalography (MEG, EEG) are essential techniques for studying distributed signal dynamics in the human brain. In particular, the functional role of neural oscillations remains to be clarified. Imaging methods need to identify distinct brain regions that concurrently generate oscillatory activity, with adequate separation in space and time. Yet, spatial smearing and inhomogeneous signal-to-noise are challenging factors to source reconstruction from external sensor data. The detection of weak sources in the presence of stronger regional activity nearby is a typical complication of MEG/EEG source imaging. We propose a novel, hypothesis-driven source reconstruction approach to address these methodological challenges1. The imaging with embedded statistics (iES) method is a subspace scanning technique that constrains the mapping problem to the actual experimental design. A major benefit is that, regardless of signal strength, the contributions from all oscillatory sources, which activity is consistent with the tested hypothesis, are equalized in the statistical maps produced. We present extensive evaluations of iES on group MEG data, for mapping 1) induced oscillations using experimental contrasts, 2) ongoing narrow-band oscillations in the resting-state, 3) co-modulation of brain-wide oscillatory power with a seed region, and 4) co-modulation of oscillatory power with peripheral signals (pupil dilation). Along the way, we demonstrate several advantages of iES over standard source imaging approaches. These include the detection of oscillatory coupling without rejection of zero-phase coupling, and detection of ongoing oscillations in deeper brain regions, where signal-to-noise conditions are unfavorable. We also show that iES provides a separate evaluation of oscillatory synchronization and desynchronization in experimental contrasts, which has important statistical advantages. The flexibility of iES allows it to be adjusted to many experimental questions in systems neuroscience.Author summaryThe oscillatory activity of the brain produces a repertoire of signal dynamics that is rich and complex. Noninvasive recording techniques such as scalp magnetoencephalography and electroencephalography (MEG, EEG) are key methods to advance our comprehension of the role played by neural oscillations in brain functions and dysfunctions. Yet, there are methodological challenges in mapping these elusive components of brain activity that have remained unresolved. We introduce a new mapping technique, called imaging with embedded statistics (iES), which alleviates these difficulties. With iES, signal detection is constrained explicitly to the operational hypotheses of the study design. We show, in a variety of experimental contexts, how iES emphasizes the oscillatory components of brain activity, if any, that match the experimental hypotheses, even in deeper brain regions where signal strength is expected to be weak in MEG. Overall, the proposed method is a new imaging tool to respond to a wide range of neuroscience questions concerning the scaffolding of brain dynamics via anatomically-distributed neural oscillations.

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Functional Properties of Neurons in the Primate Tongue Primary Motor Cortex During Swallowing

Journal of Neurophysiology ◽

10.1152/jn.1997.78.3.1516 ◽

1997 ◽

Vol 78 (3) ◽

pp. 1516-1530 ◽

Cited By ~ 76

Author(s):

Ruth E. Martin ◽

Gregory M. Murray ◽

Pentti Kemppainen ◽

Yuji Masuda ◽

Barry J. Sessle

Keyword(s):

Motor Cortex ◽

Functional Properties ◽

Primary Motor Cortex ◽

Motor Behavior ◽

Critical Role ◽

Electromyographic Activity ◽

Related Activity ◽

Tongue Protrusion ◽

Significant Difference ◽

Tongue Movements

Martin, Ruth E., Gregory M. Murray, Pentti Kemppainen, Yuji Masuda, and Barry J. Sessle. Functional properties of neurons in the primate tongue primary motor cortex during swallowing. J. Neurophysiol. 78: 1516–1530, 1997. Recent studies conducted in our laboratory have suggested that the tongue primary motor cortex (i.e., tongue-MI) plays a critical role in the control of voluntary tongue movements in the primate. However, the possible involvement of tongue-MI in semiautomatic tongue movements, such as those in swallowing, remains unkown. Therefore the present study was undertakein in attempts to address whether tongue-MI plays a role in the semiautomatic tongue movements produced during swallowing. Extracellular single neuron recordings were obtained from tongue-MI, defined by intracortical microstimulation (ICMS), in two awake monkeys as they performed three types of swallowing (swallowing of a juice reward after successful tongue task performance, nontask-related swallowing of a liquid bolus, and nontask-related swallowing of a solid bolus) as well as a trained tongue-protrusion task. Electromyographic activity was recorded simultaneously from various orofacial and laryngeal muscles. In addition, the afferent input to each tongue-MI neuron and ICMS-evoked motor output characteristics at each neuronal recording site were determined. Neurons were considered to show swallow and/or tongue-protrusion task-related activity if a statistically significant difference in firing rate was seen in association with these behaviors compared with that observed during a control pretrial period. Of a total of 80 neurons recorded along 40 microelectrode penetrations in the ICMS-defined tongue-MI, 69% showed significant alterations of activity in relation to the swallowing of a juice reward, whereas 66% exhibited significant modulations of firing in association with performance of the trained tongue-protrusion task. Moreover, 48% showed significant alterations of firing in relation to both swallowing and the tongue-protrusion task. These findings suggest that the region of cortex involved in swallowing includes MI and that tongue-MI may play a role in the regulation of semiautomatic tongue movement, in addition to trained motor behavior. Swallow-related tongue-MI neurons exhibited a variety of swallow-related activity patterns and were distributed throughout the ICMS-defined tongue-MI at sites where ICMS evoked a variety of types of tongue movements. These findings are consistent with the view that multiple efferent zones for the production of tongue movements are activated in swallowing. Many swallow-related tongue-MI neurons had an orofacial mechanoreceptive field, particularly on the tongue dorsum, supporting the view that afferent inputs may be involved in the regulation of the swallowing synergy.

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Protective role of mirtazapine in adult female Mecp2+/− mice and patients with Rett syndrome

Journal of Neurodevelopmental Disorders ◽

10.1186/s11689-020-09328-z ◽

2020 ◽

Vol 12 (1) ◽

Author(s):

Javier Flores Gutiérrez ◽

Claudio De Felice ◽

Giulia Natali ◽

Silvia Leoncini ◽

Cinzia Signorini ◽

...

Keyword(s):

Motor Cortex ◽

Motor Learning ◽

Disease Progression ◽

Rett Syndrome ◽

Adult Female ◽

Primary Motor Cortex ◽

Barrel Cortex ◽

Motor Behavior ◽

Clinical Severity ◽

Long Term Treatment

Abstract Background Rett syndrome (RTT), an X-linked neurodevelopmental rare disease mainly caused by MECP2-gene mutations, is a prototypic intellectual disability disorder. Reversibility of RTT-like phenotypes in an adult mouse model lacking the Mecp2-gene has given hope of treating the disease at any age. However, adult RTT patients still urge for new treatments. Given the relationship between RTT and monoamine deficiency, we investigated mirtazapine (MTZ), a noradrenergic and specific-serotonergic antidepressant, as a potential treatment. Methods Adult heterozygous-Mecp2 (HET) female mice (6-months old) were treated for 30 days with 10 mg/kg MTZ and assessed for general health, motor skills, motor learning, and anxiety. Motor cortex, somatosensory cortex, and amygdala were analyzed for parvalbumin expression. Eighty RTT adult female patients harboring a pathogenic MECP2 mutation were randomly assigned to treatment to MTZ for insomnia and mood disorders (mean age = 23.1 ± 7.5 years, range = 16–47 years; mean MTZ-treatment duration = 1.64 ± 1.0 years, range = 0.08–5.0 years). Rett clinical severity scale (RCSS) and motor behavior assessment scale (MBAS) were retrospectively analyzed. Results In HET mice, MTZ preserved motor learning from deterioration and normalized parvalbumin levels in the primary motor cortex. Moreover, MTZ rescued the aberrant open-arm preference behavior observed in HET mice in the elevated plus-maze (EPM) and normalized parvalbumin expression in the barrel cortex. Since whisker clipping also abolished the EPM-related phenotype, we propose it is due to sensory hypersensitivity. In patients, MTZ slowed disease progression or induced significant improvements for 10/16 MBAS-items of the M1 social behavior area: 4/7 items of the M2 oro-facial/respiratory area and 8/14 items of the M3 motor/physical signs area. Conclusions This study provides the first evidence that long-term treatment of adult female heterozygous Mecp2tm1.1Bird mice and adult Rett patients with the antidepressant mirtazapine is well tolerated and that it protects from disease progression and improves motor, sensory, and behavioral symptoms.

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Functional properties of single neurons in the face primary motor cortex of the primate. II. Relations with trained orofacial motor behavior

Journal of Neurophysiology ◽

10.1152/jn.1992.67.3.759 ◽

1992 ◽

Vol 67 (3) ◽

pp. 759-774 ◽

Cited By ~ 42

Author(s):

G. M. Murray ◽

B. J. Sessle

Keyword(s):

Motor Cortex ◽

Cortical Neurons ◽

Primary Motor Cortex ◽

Motor Behavior ◽

Afferent Input ◽

Single Neurons ◽

Tongue Protrusion ◽

Input And Output ◽

The Face ◽

Tongue Movements

1. The previous paper has described in detail the input and output features of single neurons located at sites within primate face motor cortex from which intracortical microstimulation (ICMS, less than or equal to 20 microA) evoked tongue movements at the lowest threshold ("tongue-MI" sites); for comparative purposes, we also reported on the input and output features of a smaller number of neurons recorded at sites from which ICMS could evoke jaw movements ("jaw-MI" sites), facial movements ("face-MI" sites), or, at a few sites, tongue movements and, at the same threshold intensity, either a jaw movement or a facial movement. 2. Our findings of an extensive and diverse representation of sites within face motor cortex of monkeys for the generation of elemental components of tongue movement, and the relatively few sites from which jaw-closing movements could be evoked, were consistent with our recent observations that reversible, cooling-induced inactivation of the face motor cortex severely impaired the performance by monkeys of a tongue-protrusion task but had only relatively minor effects on the performance of a biting task. In an attempt to establish a neuronal correlate for these different behavioral relations, the present study has documented the task-related activities of those single neurons that were characterized in the previous paper in terms of afferent input and ICMS-defined output features. 3. Each task required the development and maintenance by each monkey of a fixed force level for a minimum period of time to obtain a fruit-juice reward. During one or both of these tasks, we characterized the activities of 231 single face motor cortical neurons that were located at the above-mentioned ICMS-defined sites. Neurons were said to be related to a particular task if they showed statistically significant differences in firing rates during the task in comparison with a control pretrial period (PTP). 4. In tongue-MI, there was a significantly higher proportion of neurons (63% of 156 neurons tested) that were related to the tongue-protrusion task than to the biting task (15% of 65). However, in jaw-MI the proportion of neurons that were biting task-related (63% of 19) was significantly higher than the proportion related to the tongue-protrusion task (11% of 9); the proportion of biting task-related neurons at ICMS-defined jaw-closing sites was also higher than that at jaw-opening sites.(ABSTRACT TRUNCATED AT 400 WORDS)

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