Quantitative Evidence for Direct Effects between Earth-Ionosphere Schumann Resonances and Human Cerebral Cortical Activity

The multiple quantitative similarities of basic frequencies, harmonics, magnetic field intensities, voltages, band widths, and energetic solutions that define the Schumann resonances within the separation between the earth and ionosphere and the activity within the human cerebral cortices suggest the capacity for direct interaction. The recent experimental demonstration of the representations of the Schumann resonances within the spectral densities of normal human quantitative electroencephalographic (QEEG) activity suggests a casual interaction. Calculations supported by correlations between amplitudes of the global Schumann resonances measured several thousands of km away (which were nearly identical to our local measurements) and the coherence and current densities or these frequency bands between cerebral hemispheres for a large population of human QEEG measures indicate that such interaction occurs. The energies are within the range that would allow information to be exchanged between cerebral and Schumann sources. The near-identical solution for current density from the increasing human population and background vertical electric fields suggests that changes in the former might determine the degree of coherence between the Schumann resonances. Direct comparisons of local Schumann measurements and brain activity exhibited powerful intermittent coherence within the first three harmonics. Implications of the contributions of solar transients, surface temperature, and rapidly developing technologies to modify the ionosphere’s Schumann properties are considered.

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Multi-shanks SiNAPS Active Pixel Sensor CMOS probe: 1024 simultaneously recording channels for high-density intracortical brain mapping

10.1101/749911 ◽

2019 ◽

Author(s):

Fabio Boi ◽

Nikolas Perentos ◽

Aziliz Lecomte ◽

Gerrit Schwesig ◽

Stefano Zordan ◽

...

Keyword(s):

Neural Activity ◽

Brain Activity ◽

Brain Area ◽

Large Population ◽

Brain Structures ◽

High Density ◽

Single Neurons ◽

Electrode Arrays ◽

Unit Recording ◽

Recording Channels

AbstractThe advent of implantable active dense CMOS neural probes opened a new era for electrophysiology in neuroscience. These single shank electrode arrays, and the emerging tailored analysis tools, provide for the first time to neuroscientists the neurotechnology means to spatiotemporally resolve the activity of hundreds of different single-neurons in multiple vertically aligned brain structures. However, while these unprecedented experimental capabilities to study columnar brain properties are a big leap forward in neuroscience, there is the need to spatially distribute electrodes also horizontally. Closely spacing and consistently placing in well-defined geometrical arrangement multiple isolated single-shank probes is methodologically and economically impractical. Here, we present the first high-density CMOS neural probe with multiple shanks integrating thousand’s of closely spaced and simultaneously recording microelectrodes to map neural activity across 2D lattice. Taking advantage from the high-modularity of our electrode-pixels-based SiNAPS technology, we realized a four shanks active dense probe with 256 electrode-pixels/shank and a pitch of 28 µm, for a total of 1024 simultaneously recording channels. The achieved performances allow for full-band, whole-array read-outs at 25 kHz/channel, show a measured input referred noise in the action potential band (300-7000 Hz) of 6.5 ± 2.1µVRMS, and a power consumption <6 µW/electrode-pixel. Preliminary recordings in awake behaving mice demonstrated the capability of multi-shanks SiNAPS probes to simultaneously record neural activity (both LFPs and spikes) from a brain area >6 mm2, spanning cortical, hippocampal and thalamic regions. High-density 2D array enables combining large population unit recording across distributed networks with precise intra- and interlaminar/nuclear mapping of the oscillatory dynamics. These results pave the way to a new generation of high-density and extremely compact multi-shanks CMOS-probes with tunable layouts for electrophysiological mapping of brain activity at the single-neurons resolution.

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Endogenous and exogenous electric fields as modifiers of brain activity: rational design of noninvasive brain stimulation with transcranial alternating current stimulation

Dialogues in Clinical Neuroscience ◽

10.31887/dcns.2014.16.1/ffroehlich ◽

2014 ◽

Vol 16 (1) ◽

pp. 93-102 ◽

Cited By ~ 15

Keyword(s):

Electric Fields ◽

Brain Stimulation ◽

Rational Design ◽

Brain Activity ◽

Field Potential ◽

Alternating Current ◽

Noninvasive Brain Stimulation ◽

Starting Point ◽

Recent Developments ◽

Transcranial Alternating Current Stimulation

Synchronized neuronal activity in the cortex generates weak electric fields that are routinely measured in humans and animal models by electroencephalography and local field potential recordings. Traditionally, these endogenous electric fields have been considered to be an epiphenomenon of brain activity. Recent work has demonstrated that active cortical networks are surprisingly susceptible to weak perturbations of the membrane voltage of a large number of neurons by electric fields. Simultaneously, noninvasive brain stimulation with weak, exogenous electric fields (transcranial current stimulation, TCS) has undergone a renaissance due to the broad scope of its possible applications in modulating brain activity for cognitive enhancement and treatment of brain disorders. This review aims to interface the recent developments in the study of both endogenous and exogenous electric fields, with a particular focus on rhythmic stimulation for the modulation of cortical oscillations. The main goal is to provide a starting point for the use of rational design for the development of novel mechanism-based TCS therapeutics based on transcranial alternating current stimulation, for the treatment of psychiatric illnesses.

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Glycosidases in Normal Human Leukocytes and Abnormalities in GM1-Gangliosidosis

Clinical Chemistry ◽

10.1093/clinchem/18.9.971 ◽

1972 ◽

Vol 18 (9) ◽

pp. 971-975 ◽

Cited By ~ 33

Author(s):

Jeffrey Hindman ◽

Edward Cotlier

Keyword(s):

Enzyme Assay ◽

Large Population ◽

Genetic Defect ◽

Normal Subjects ◽

Confidence Limits ◽

Gm1 Gangliosidosis ◽

Glycosidase Activity ◽

Normal Ranges ◽

Normal Human ◽

Single Enzyme

Abstract Leukocyte enzyme assay is a valuable tool in the diagnosis of mucolipidoses and glycosphingolipidoses. Accurate resolution of the normal ranges of glycosidase activity is vital in the evaluation of both homozygotes and suspected heterozygote carriers. Activities of leukocyte β-galactosidase, α-galactosidase, α-mannosidase, β-fucosidase, β-glucosaminidase, and β-galactosaminidase were measured in a large population of normal subjects and demonstrated, within 95% confidence limits, to be normally distributed. Leukocyte glycosidases were determined in a GM1-gangliosidosis homozygote and in the heterozygous parents. A previously unreported deficiency of β-fucosidase and the well-known deficiency of β-galactosidase were demonstrated in the proband, and corresponding but less severe deficiencies of both glycosidases were found in the parents. β-Galactosidase and β-fucosidase may represent a single enzyme, unspecific for the carbon 6 of galactose. If not, the genetic defect in GM1-gangliosidosis may be more profound than has been recognized.

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The Separation of Normal Human Leukocytes by Density and Classification by Size

Blood ◽

10.1182/blood.v34.5.591.591 ◽

1969 ◽

Vol 34 (5) ◽

pp. 591-600 ◽

Cited By ~ 32

Author(s):

ROBERT M. ZUCKER ◽

BENEDICT CASSEN

Keyword(s):

Blood Cells ◽

Large Population ◽

Cell Populations ◽

Lymphocyte Population ◽

Small Lymphocyte ◽

Density Fractions ◽

Normal Human ◽

Leukocyte Populations ◽

Differential Counts ◽

Normal Human Blood

Abstract Leukocytes of hematologically normal human blood have been studied by separating them in bovine serum albumin gradients. The blood cells of the density fractions have been characterized by electronic volume sizing and microscope differential counts. The electronic volumes of different leukocyte populations have been determined from density gradient experiments. Lymphocytes of various sizes can be separated by differences in density. The small lymphocyte population is the most dense while the large population is the least dense. The density of blood cell populations in BSA in order of increasing density were: monocytes, lymphocytes, granulocytes and erythrocytes.

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Transcranial brain stimulation: potential and limitations

e-Neuroforum ◽

10.1515/s13295-014-0056-6 ◽

2014 ◽

Vol 20 (2) ◽

Author(s):

W. Paulus

Keyword(s):

Electric Fields ◽

Magnetic Stimulation ◽

Near Infrared ◽

Brain Activity ◽

Electrical Energy ◽

After Effects ◽

Network Characteristics ◽

Neuronal Membranes ◽

Transcranial Brain Stimulation ◽

The Brain

AbstractThe brain adapts to new requirements in response to activity, learning or reactions to environmental stimuli by continuous reorganization. These reorganization processes can be facilitated and augmented, or also inhibited and prevented, by transcranial neurostimulation. The most common methods are electrical or magnetic stimulation. However, few studies have dealt with the newer methods using near infrared or ultrasound stimulation.Transcranial magnetic stimulation (TMS) allows the pain-free transfer of very short bursts of high intensity electrical energy through the skull and can induce action potentials. By varying the number and intensity of the stimuli, and the stimulus sequence, repetitive TMS (rTMS) can induce either inhibitory or facilitatory effects in the brain. A differentiation is made between short-lived interference with ongoing brain activity, and plastic changes that persist for a longer period beyond the end of the stimulation.Weaker electric fields in the 1 mA range can be applied painlessly through the skull. These probably exert their effects by modulating neuronal membranes and influencing the spontaneous firing rate of cortical neurons. They encompass the range from transcranial direct current stimulation (tDCS) to high frequency alternating current stimulation (tACS) in the kilohertz range. In view of the multitude of physically possible stimulation algorithms, hypothesis-driven protocols based on cellular or neuronal network characteristics are particularly popular, in the effort to narrow the choices in a meaningful manner. Examples are theta burst stimulation or tACS in the so-called “ripple” frequency range. It is, of course, not possible to selectively stimulate individual neurons using transcranial stimulation techniques; however selective after-effects can be achieved when used in combination with neuropharmacologically active drugs. The use of these methods for neuroenhancement is now a topic of intense discussion.

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Deep Learning for Non-Invasive Cortical Potential Imaging

10.1101/2020.06.15.151480 ◽

2020 ◽

Author(s):

Alexandra Razorenova ◽

Nikolay Yavich ◽

Mikhail Malovichko ◽

Maxim Fedorov ◽

Nikolay Koshev ◽

...

Keyword(s):

Inverse Problem ◽

Deep Learning ◽

Electric Fields ◽

Spatial Resolution ◽

Brain Activity ◽

Invasive Technique ◽

Problem Solver ◽

Deep Convolutional Neural Networks ◽

Non Invasive ◽

Cortical Potential Imaging

AbstractElectroencephalography (EEG) is a well-established non-invasive technique to measure the brain activity, albeit with a limited spatial resolution. Variations in electric conductivity between different tissues distort the electric fields generated by cortical sources, resulting in smeared potential measurements on the scalp. One needs to solve an ill-posed inverse problem to recover the original neural activity. In this article, we present a generic method of recovering the cortical potentials from the EEG measurement by introducing a new inverse-problem solver based on deep Convolutional Neural Networks (CNN) in paired (U-Net) and unpaired (DualGAN) configurations. The solvers were trained on synthetic EEG-ECoG pairs that were generated using a head conductivity model computed using the Finite Element Method (FEM). These solvers are the first of their kind, that provide robust translation of EEG data to the cortex surface using deep learning. Providing a fast and accurate interpretation of the tracked EEG signal, our approach promises a boost to the spatial resolution of the future EEG devices.

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Realistic modeling of ephaptic fields in the human brain

10.1101/688101 ◽

2019 ◽

Cited By ~ 2

Author(s):

Giulio Ruffini ◽

Ricardo Salvador ◽

Ehsan Tadayon ◽

Roser Sanchez-Todo ◽

Alvaro Pascual-Leone ◽

...

Keyword(s):

Human Brain ◽

Electric Fields ◽

Neuronal Activity ◽

Direct Interaction ◽

Pyramidal Cells ◽

Brain Structures ◽

Relative Orientation ◽

Transcranial Brain Stimulation ◽

Potential Perturbation ◽

Human Function

AbstractSeveral decades of research suggest that weak electric fields may influence neural processing, including those induced by neuronal activity and recently proposed as substrate for a potential new cellular communication system, i.e., ephaptic transmission. Here we aim to map ephaptic activity in the human brain and explore its trajectory during aging by characterizing the macroscopic electric field generated by cortical dipoles using realistic finite element modeling. We find that modeled endogenous field magnitudes are comparable to those in measurements of weak but functionally relevant endogenous fields and to those generated by noninvasive transcranial brain stimulation, therefore possibly able to modulate neuronal activity. Then, to evaluate the role of self-generated ephaptic fields in the human cortex, we adapt an interaction approximation that considers the relative orientation of neuron and field to derive the membrane potential perturbation in pyramidal cells. Building on this, we define a simplified metric (EMOD1) that weights dipole coupling as a function of distance and relative orientation between emitter and receiver and evaluate it in a sample of 401 realistic human brain models from subjects aged 16-83. Results reveal that ephaptic modulation follows gyrification patterns in the human brain, and significantly decreases with age, with higher involvement of sensorimotor regions and medial brain structures. By providing the means for fast and direct interaction between neurons, ephaptic modulation likely contributes to the complexity of human function for cognition and behavior, and its modification across the lifespan and in response to pathology.

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Dose-Dependent Effects of Transcranial Alternating Current Stimulation on Spike Timing in Awake Nonhuman Primates

10.1101/696344 ◽

2019 ◽

Cited By ~ 6

Author(s):

Luke Johnson ◽

Ivan Alekseichuk ◽

Jordan Krieg ◽

Alex Doyle ◽

Ying Yu ◽

...

Keyword(s):

Electric Fields ◽

Nonhuman Primates ◽

Brain Activity ◽

Alternating Current ◽

Spike Timing ◽

Novel Treatments ◽

Dose Dependent Fashion ◽

Transcranial Alternating Current Stimulation ◽

Dose Dependent

ABSTRACTWeak extracellular electric fields can influence spike timing in neural networks. Approaches to impose such fields on the brain in a noninvasive manner have high potential for novel treatments of neurological and psychiatric disorders. One of these methods, transcranial alternating current stimulation (TACS), is hypothesized to affect spike timing and cause neural entrainment. However, the conditions under which these effects occur in-vivo are unknown. Here, we show that TACS modulates spike timing in awake nonhuman primates (NHPs) in a dose-dependent fashion. Recording single-unit activity from pre-and post-central gyrus regions in NHPs during TACS, we found that a larger population of neurons became entrained to the stimulation waveform for higher stimulation intensities. Performing a cluster analysis of changes in interspike intervals, we identified two main types of neural responses to TACS – increased burstiness and phase entrainment. Our results demonstrate the ability of TACS to affect spike-timing in the awake primate brain and identify fundamental neural mechanisms. Concurrent electric field recordings demonstrate that spike-timing changes occur with stimulation intensities readily achievable in humans. These results suggest that novel TACS protocols tailored to ongoing brain activity may be a potent tool to normalize spike-timing in maladaptive brain networks and neurological disease.

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Direct Interaction of ATP7B and LC3B Proteins Suggests a Cooperative Role of Copper Transportation and Autophagy

10.20944/preprints202110.0137.v1 ◽

2021 ◽

Author(s):

Supansa Pantoom ◽

Adam Pomorski ◽

Katharina Huth ◽

Christina Hund ◽

Janine Petters ◽

...

Keyword(s):

Direct Interaction ◽

Copper Metabolism ◽

Central Protein ◽

Potential Binding ◽

Normal Human ◽

Autophagy Pathway ◽

Interaction Regions ◽

Cellular Copper

Macroautophagy/autophagy plays an important role in cellular copper clearance. The means by which the copper metabolism and autophagy pathways interact mechanistically is vastly unexplored. Dysfunctional ATP7B, a copper-transporting ATPase, is involved in the development of monogenic Wilson disease, a disorder characterized by disturbed copper transport. Using in silico prediction, we found that ATP7B contains a number of potential binding sites for LC3, a central protein in autophagy pathway, so-called LC3 interaction regions (LIRs). The conserved LIR3, located at the C-terminal end of ATP7B, was found to directly interact with LC3B in vitro. Replacing the two conserved hydrophobic residues W1452 and L1455 of LIR3 significantly reduced interaction. Furthermore, autophagy was induced in normal human hepatocellular carcinoma cells (HepG2) leading to enhanced colocalization of ATP7B and LC3B on the autophagosome membranes. By contrast, HepG2 cells deficient of ATP7B (HepG2 ATP7B-/-) showed autophagy deficiency at elevated copper condition. This phenotype was complemented by heterologous ATP7B expression. These findings suggest a cooperative role of ATP7B and LC3B in autophagy-mediated copper clearance.

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Combined behavioral and electrophysiological evidence for a direct cortical effect of prefrontal tDCS on disorders of consciousness

10.1101/612309 ◽

2019 ◽

Author(s):

Bertrand Hermann ◽

Federico Raimondo ◽

Lukas Hirsch ◽

Yu Huang ◽

Mélanie Denis-Valente ◽

...

Keyword(s):

Electric Fields ◽

Brain Injuries ◽

Causal Effect ◽

Brain Activity ◽

Vegetative State ◽

Behavioral Assessment ◽

Minimally Conscious State ◽

Conscious State ◽

Disorders Of Consciousness ◽

Open Label

ABSTRACTSevere brain injuries can lead to long-lasting disorders of consciousness (DoC) such as vegetative state/unresponsive wakefulness syndrome (VS/UWS) or minimally conscious state (MCS). While behavioral assessment remains the gold standard to determine conscious state, EEG has proven to be a promising complementary tool to monitor the effect of new therapeutics. Encouraging results have been obtained with invasive electrical stimulation of the brain, and recent studies identified transcranial direct current stimulation (tDCS) as an effective approach in randomized controlled trials. This non-invasive and inexpensive tool may turn out to be the preferred treatment option. However, its mechanisms of action and physiological effects on brain activity remain unclear and debated. Here, we stimulated 60 DoC patients with the anode placed over left-dorsolateral prefrontal cortex in a prospective open-label study. Clinical behavioral assessment improved in twelve patients (20%) and none deteriorated. This behavioral response after tDCS coincided with an enhancement of putative EEG markers of consciousness: in comparison with non-responders, responders showed increases of power and long-range cortico-cortical functional connectivity in the theta-alpha band, and a larger and more sustained P300 suggesting improved conscious access to auditory novelty. The EEG changes correlated with electric fields strengths in prefrontal cortices, and no correlation was found on the scalp. Taken together, this prospective intervention in a large cohort of DoC patients strengthens the validity of the proposed EEG signatures of consciousness, and is suggestive of a direct causal effect of tDCS on consciousness.

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