scholarly journals Increasing and decreasing interregional brain coupling increases and decreases oscillatory activity in the human brain

2021 ◽  
Vol 118 (37) ◽  
pp. e2100652118
Author(s):  
Alejandra Sel ◽  
Lennart Verhagen ◽  
Katharina Angerer ◽  
Raluca David ◽  
Miriam C. Klein-Flügge ◽  
...  
Keyword(s):  
Human Brain ◽  
Alpha Rhythm ◽  
Primary Motor Cortex ◽  
Premotor Cortex ◽  
Motor Task ◽  
Brain Regions ◽  
Spike Timing ◽  
Oscillatory Activity ◽  
The Impact ◽  
The Brain

The origins of oscillatory activity in the brain are currently debated, but common to many hypotheses is the notion that they reflect interactions between brain areas. Here, we examine this possibility by manipulating the strength of coupling between two human brain regions, ventral premotor cortex (PMv) and primary motor cortex (M1), and examine the impact on oscillatory activity in the motor system measurable in the electroencephalogram. We either increased or decreased the strength of coupling while holding the impact on each component area in the pathway constant. This was achieved by stimulating PMv and M1 with paired pulses of transcranial magnetic stimulation using two different patterns, only one of which increases the influence exerted by PMv over M1. While the stimulation protocols differed in their temporal patterning, they were comprised of identical numbers of pulses to M1 and PMv. We measured the impact on activity in alpha, beta, and theta bands during a motor task in which participants either made a preprepared action (Go) or withheld it (No-Go). Augmenting cortical connectivity between PMv and M1, by evoking synchronous pre- and postsynaptic activity in the PMv–M1 pathway, enhanced oscillatory beta and theta rhythms in Go and No-Go trials, respectively. Little change was observed in the alpha rhythm. By contrast, diminishing the influence of PMv over M1 decreased oscillatory beta and theta rhythms in Go and No-Go trials, respectively. This suggests that corticocortical communication frequencies in the PMv–M1 pathway can be manipulated following Hebbian spike-timing–dependent plasticity.

scholarly journals Repetitive Transcranial Magnetic Stimulation Improves Handwriting in Parkinson’s Disease

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Bubblepreet K. Randhawa ◽  
Becky G. Farley ◽  
Lara A. Boyd
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Brain Stimulation ◽  
Magnetic Stimulation ◽  
Primary Motor Cortex ◽  
Cortical Excitability ◽  
Repetitive Transcranial Magnetic Stimulation ◽  
Motor Task ◽  
Brain Regions ◽  
Fine Motor ◽  
The Impact

Background. Parkinson disease (PD) is characterized by hypometric movements resulting from loss of dopaminergic neurons in the substantia nigra. PD leads to decreased activation of the supplementary motor area (SMA); the net result of these changes is a poverty of movement. The present study determined the impact of 5 Hz repetitive transcranial magnetic stimulation (rTMS) over the SMA on a fine motor movement, handwriting (writing cursive “l”s), and on cortical excitability, in individuals with PD.Methods. In a cross-over design, ten individuals with PD were randomized to receive either 5 Hz or control stimulation over the SMA. Immediately following brain stimulation right handed writing was assessed.Results. 5 Hz stimulation increased vertical size of handwriting and diminished axial pressure. In addition, 5 Hz rTMS significantly decreased the threshold for excitability in the primary motor cortex.Conclusions. These data suggest that in the short term 5 Hz rTMS benefits functional fine motor task performance, perhaps by altering cortical excitability across a network of brain regions. Further, these data may provide the foundation for a larger investigation of the effects of noninvasive brain stimulation over the SMA in individuals with PD.

scholarly journals Characterization of functional diversity of the human brain based on intrinsic connectivity networks

2018 ◽  
Author(s):  
Congying Chu ◽  
Lingzhong Fan ◽  
Tianzi Jiang
Keyword(s):  
Human Brain ◽  
Functional Diversity ◽  
Functional Properties ◽  
Large Scale ◽  
Primary Motor Cortex ◽  
Brain Activity ◽  
Brain Regions ◽  
Intrinsic Connectivity ◽  
Intrinsic Connectivity Networks ◽  
The Brain

AbstractSpontaneous fluctuations underlying the brain activity can reflect the intrinsic organization of the system, such as the functional brain networks. In large scale, a network perspective has emerged as a new avenue to explore the functional properties of human brain. Here, we studied functional diversity in healthy subjects based on the network perspective. We hypothesized that the patterns of participation of different functional networks were related with the functional diversity of particular brain regions. Independent component analysis (ICA) was adopted to detect the intrinsic connectivity networks (ICNs) based on the data of resting-state functional MRI. An index of functional diversity (FD index) was proposed to quantitatively describe the degree of anisotropic distribution related with participation of various ICNs. We found that FD index continuously varied across the brain, for example, the primary motor cortex with low FD value and the precuneus with significantly high FD value. The FD values indicated the different functional roles of the corresponding brain regions, which were reflected by the various patterns of participation of ICNs. The FD index can be used as a new approach to quantitatively characterize the functional diversity of human brain, even for the changed functional properties caused by the psychiatric disorders.

scholarly journals The impact of genomic structural variation on the transcriptome, chromatin, and proteome in the human brain

2021 ◽  
Author(s):  
Ricardo A Vialle ◽  
Katia de Paiva Lopes ◽  
David A Bennett ◽  
John F Crary ◽  
Towfique Raj
Keyword(s):  
Human Brain ◽  
Structural Variation ◽  
Brain Regions ◽  
Cis Acting ◽  
Genomic Structural Variation ◽  
Protein Levels ◽  
Post Mortem Brain ◽  
Whole Genomes ◽  
The Impact ◽  
The Brain

Structural variants (SVs), defined as any genomic rearrangements of 50 or more bp, are an important source of genetic diversity and have been linked to many diseases. However, their contribution to molecular traits in the brain and impact on neurodegenerative diseases remains unknown. Here, we report 170,996 SVs which were constructed using 1,760 short-read whole genomes from aging and Alzheimer's disease subjects. We quantified the impact of cis-acting SVs on several molecular traits including histone modification, gene expression, mRNA splicing, and protein abundance in post-mortem brain tissues. More than 3,800 genes were associated with at least one molecular phenotype, and 712 (18%) with more than one phenotype, with a significant positive correlation in the direction of effect between RNA, histone peaks, and protein levels. SV associations with RNA and protein levels shared the same direction of effect in more than 87% of SV-gene pairs. We found reproducibility of SV-eQTLs across three groups of samples and multiple brain regions ranging from 81 to 98%, including the innate immune system related genes ERAP2 and GBP3. Additionally, associations of SVs with progressive supranuclear palsy, an amyloid-independent primary tauopathy, identified previously known and novel SVs at the 17q.21.31 MAPT locus and several other novel suggestive associations. Our study provides a comprehensive view of the mechanisms linking structural variation to gene regulation and provides a valuable resource for understanding the functional impact of SVs in the aged human brain.

scholarly journals Developmental cannabidiol exposure increases anxiety and modifies genome-wide brain DNA methylation in adult female mice

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Nicole M. Wanner ◽  
Mathia Colwell ◽  
Chelsea Drown ◽  
Christopher Faulk
Keyword(s):  
Dna Methylation ◽  
Molecular Mechanisms ◽  
Coat Color ◽  
Brain Regions ◽  
Functional Enrichment ◽  
Positive Effects ◽  
Genome Wide ◽  
Nulliparous Female ◽  
The Impact ◽  
The Brain

Abstract Background Use of cannabidiol (CBD), the primary non-psychoactive compound found in cannabis, has recently risen dramatically, while relatively little is known about the underlying molecular mechanisms of its effects. Previous work indicates that direct CBD exposure strongly impacts the brain, with anxiolytic, antidepressant, antipsychotic, and other effects being observed in animal and human studies. The epigenome, particularly DNA methylation, is responsive to environmental input and can direct persistent patterns of gene regulation impacting phenotype. Epigenetic perturbation is particularly impactful during embryogenesis, when exogenous exposures can disrupt critical resetting of epigenetic marks and impart phenotypic effects lasting into adulthood. The impact of prenatal CBD exposure has not been evaluated; however, studies using the psychomimetic cannabinoid Δ9-tetrahydrocannabinol (THC) have identified detrimental effects on psychological outcomes in developmentally exposed adult offspring. We hypothesized that developmental CBD exposure would have similar negative effects on behavior mediated in part by the epigenome. Nulliparous female wild-type Agouti viable yellow (Avy) mice were exposed to 20 mg/kg CBD or vehicle daily from two weeks prior to mating through gestation and lactation. Coat color shifts, a readout of DNA methylation at the Agouti locus in this strain, were measured in F1 Avy/a offspring. Young adult F1 a/a offspring were then subjected to tests of working spatial memory and anxiety/compulsive behavior. Reduced-representation bisulfite sequencing was performed on both F0 and F1 cerebral cortex and F1 hippocampus to identify genome-wide changes in DNA methylation for direct and developmental exposure, respectively. Results F1 offspring exposed to CBD during development exhibited increased anxiety and improved memory behavior in a sex-specific manner. Further, while no significant coat color shift was observed in Avy/a offspring, thousands of differentially methylated loci (DMLs) were identified in both brain regions with functional enrichment for neurogenesis, substance use phenotypes, and other psychologically relevant terms. Conclusions These findings demonstrate for the first time that despite positive effects of direct exposure, developmental CBD is associated with mixed behavioral outcomes and perturbation of the brain epigenome.

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

Stroke ◽  
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.

scholarly journals Voluntary Movements Discipline Audiovisual Perception

2020 ◽  
Author(s):  
Ahmad Yousef
Keyword(s):  
Red Blood Cells ◽  
Blood Cells ◽  
Primary Motor Cortex ◽  
Premotor Cortex ◽  
Brain Regions ◽  
Voluntary Movements ◽  
Deep Breathing ◽  
Audiovisual Perception ◽  
Cognitive Action ◽  
Actual Material

We had shown that deep breathing had been able to effectively and timely alter visual and auditory bistable perception, see reference 1, 2. Deep breathing requires cognitive control, and therefore, in this study, we decide to investigate whether voluntary movements of human hands are able to govern the audiovisual perception using an integrative stimulus that’s built up with the aforementioned visual and auditory stimuli. Astoundingly, when the human subjects moves the pen towards the actual physical direction, even without touching the screen; the original materials of the audiovisual stimulus appear. Reversed perception, namely, illusory motion reversals and illusory word appear when the pen is moved in the opposite direction of the actual motion. Cognitive actions’ brain areas, namely, dorsolateral prefrontal cortex, premotor cortex, and primary motor cortex may require high concentration of oxygenated hobgoblin red blood cells to achieve fulsome executive movements; and this could results in significant reduction of the concentrations of the oxygenated hobgoblin red blood cells in the visual and auditory cortices. Reductions that disallow one of two; the central versus the peripheral conscious brains dedicated for audiovisual perceptions, to rapidly alternate their conscious productions; and therefore, stoppage against bistable audiovisual perception will occur. We thus hypothesis that the DLPFC may send signals to deactivate the peripheral areas in the sensory brain regions when the cognitive action is harmonized with the actual material; but it may send a contrary signal to deactivate the central areas in the sensory brain regions when the cognitive action and the actual material are disharmonized.

scholarly journals Estimation of the Directions of Alpha Rhythm Elementary Sources Using the Method of Human Brain Functional Tomography Based On the Magnetic Encephalography Data

2018 ◽  
Vol 13 (2) ◽  
pp. 426-436 ◽  
Author(s):  
M.N. Ustinin ◽  
S.D. Rykunov ◽  
A.I. Boyko ◽  
O.A. Maslova ◽  
K.D. Walton ◽  
...  
Keyword(s):  
Inverse Problem ◽  
Time Series ◽  
Human Brain ◽  
Alpha Rhythm ◽  
Brain Activity ◽  
Problem Solution ◽  
New York University ◽  
Magnetic Encephalography ◽  
The Brain ◽  
Calculation Grid

New method for the magnetic encephalography data analysis was proposed. The method transforms multichannel time series into the spatial structure of the human brain activity. In this paper we further develop this method to determine the dominant direction of the electrical sources of brain activity at each node of the calculation grid. We have considered the experimental data, obtained with three 275-channel magnetic encephalographs in New York University, McGill University and Montreal University. The human alpha rhythm phenomenon was selected as a model object. Magnetic encephalograms of the brain spontaneous activity were registered for 5-7 minutes in magnetically shielded room. Detailed multichannel spectra were obtained by the Fourier transform of the whole time series. For all spectral components, the inverse problem was solved in elementary current dipole model and the functional structure of the brain activity was calculated in the frequency band 8-12 Hz. In order to estimate the local activity direction, at the each node of calculation grid the vector of the inverse problem solution was selected, having the maximal spectral power. So, the 3D-map of the brain activity vector field was produced – the directional functional tomogram. Such maps were generated for 15 subjects and some common patterns were revealed in the directions of the alpha rhythm elementary sources. The proposed method can be used to study the local properties of the brain activity in any spectral band and in any brain compartment.

scholarly journals Hypoxic training as a way of the human brain protection from the damaging effects of oxygen deficiency

2018 ◽  
Vol 9 (4) ◽  
pp. 33-41
Author(s):  
A. Yu. Eroshenko ◽  
N. V. Kochubejnik ◽  
D. V. Shatov ◽  
S. M. Groshilin ◽  
V. N. Sklyarov ◽  
...  
Keyword(s):  
Human Brain ◽  
Alpha Rhythm ◽  
Oxygen Deficiency ◽  
Effective Means ◽  
Brain Protection ◽  
Mental Performance ◽  
Hypoxic Training ◽  
The Brain ◽  
Integral Indicator ◽  
Damaging Effects

Objective:to evaluate the possibilities of normobaric hypoxic training (NHT) in the human brain protection from the damaging effects of oxygen defciency.Materials and methods:the study involved 18 men, aged 19-23 years, who underwent NHT: 15 treatments daily 2-hour stay in a hypoxic gas medium (HGM) having an oxygen content 15.0 ± 0.5% (HGM-15). Beforestarting the NHT (I phase), and afer 1-2 days afer its closure (II stage) were carried hypoxic samples (staying in HGM-15) before and during which the subjects were recorded the electroencephalogram (EEG) and mental performance were evaluated (the «Route» test).Results:when the frst hypoxic test was carried out, the subjects had a decrease in the alpha-rhythm index (on average by 10-15 %, p = 0.013) and its amplitude (by 10-12 %, p = 0.044) compared to the usual environmental conditions. At the same time, the share of low-amplitude slow waves increased (p = 0.019). Te integral indicator of the «Route» test during staying of the subjects in the HGM-15 decreased on average by 18% compared to the usual conditions (p <0.001). Te obtained data testifed about negative influence of staying in HGM -15 on the functioning of the higher parts of the brain. Afer carrying out NHT, all subjects showed a signifcant reduction in the negative reactions of spontaneous EEG to hypoxia: when the sample was repeated, the alpha-rhythm index and its amplitude did not change signifcantly (in comparison with air breathing), signs of excessive slow wave activity were absent. Reduction of the integral indicator of mental performance when staying in HGM-15 amounted to an average of only 6%.Conclusions:NHT in the developed regime is an effective means of the brain protection from the damaging effect of oxygen defciency and can be used in the system of physiological training of specialists to perform tasks of activity in conditions of reduced partial pressure of oxygen.

scholarly journals Complex Activity and Short-term Memories in Reciprocally Connected Cerebral Organoids

2021 ◽  
Author(s):  
Tatsuya Osaki ◽  
Yoshiho Ikeuchi
Keyword(s):  
Human Brain ◽  
Three Dimensional ◽  
Oscillatory Activity ◽  
Cellular Functions ◽  
Complex Activity ◽  
Axonal Connections ◽  
Brain Organoid ◽  
External Stimuli ◽  
The Brain

AbstractMacroscopic axonal connections in the human brain distribute information and neuronal activity across the brain. Although this complexity previously hindered elucidation of functional connectivity mechanisms, brain organoid technologies have recently provided novel avenues to investigate human brain function by constructing small segments of the brain in vitro. Here, we describe the neural activity of human cerebral organoids reciprocally connected by a bundle of axons. Compared to conventional organoids, connected organoids produced significantly more intense and complex oscillatory activity. Optogenetic manipulations revealed that the connected organoids could re-play and recapitulate over time temporal patterns found in external stimuli, indicating that the connected organoids were able to form and retain temporal memories. Our findings suggest that connected organoids may serve as powerful tools for investigating the roles of macroscopic circuits in the human brain – allowing researchers to dissect cellular functions in three-dimensional in vitro nervous system models in unprecedented ways.

Differences in spectral profiles between rostral and caudal premotor cortex when hand-eye actions are decoupled

2013 ◽  
Vol 110 (4) ◽  
pp. 952-963 ◽  
Author(s):  
Patricia F. Sayegh ◽  
Kara M. Hawkins ◽  
Kari L. Hoffman ◽  
Lauren E. Sergio
Keyword(s):  
Visual Stimulus ◽  
Rhesus Macaques ◽  
Premotor Cortex ◽  
Standard Condition ◽  
Motor Task ◽  
Movement Control ◽  
Oscillatory Activity ◽  
Visually Guided ◽  
Control Research ◽  
Spectral Profiles

The aim of this research was to understand how the brain controls voluntary movement when not directly interacting with the object of interest. In the present study, we examined the role of premotor cortex in this behavior. The goal of this study was to characterize the oscillatory activity within the caudal and rostral subdivisions of dorsal premotor cortex (PMdc and PMdr) with a change from the most basic reaching movement to one that involves a simple dissociation between the actions of the eyes and hand. We were specifically interested in how PMdr and PMdc respond when the eyes and hand are decoupled by moving along different spatial planes. We recorded single-unit activity and local field potentials within PMdr and PMdc from two rhesus macaques during performance of two types of visually guided reaches. During the standard condition, a visually guided reach was performed whereby the visual stimulus guiding the movement was the target of the reach itself. During the nonstandard condition, the visual stimulus provided information about the direction of the required movement but was not the target of the motor output. We observed distinct task-related and topographical differences between PMdr and PMdc. Our results support functional differences between PMdr and PMdc during visually guided reaching. PMdr activity appears more involved in integrating the rule-based aspects of a visually guided reach, whereas PMdc is more involved in the online updating of the decoupled reach. More broadly, our results highlight the necessity of accounting for the nonstandard nature of a motor task when interpreting movement control research data.

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