Electromagnetic radiation modulates synchronization in cortical neurons of Macaque brain

2019 ◽  
Vol 30 (08) ◽  
pp. 1950047
Author(s):  
Mary Vinaya ◽  
Rose P. Ignatius
Keyword(s):  
Electromagnetic Field ◽  
Cortical Neurons ◽  
Neural System ◽  
Inhibitory Neurons ◽  
Gamma Activity ◽  
Synaptic Coupling ◽  
Local Networks ◽  
High Gamma ◽  
Approximate Frequency ◽  
Cortical Regions

We study dynamical synchronization in a model of a neural system representing 47 cortical regions of Macaque brain under the effect of an electromagnetic field. This system is constituted by local networks of densely interconnected excitatory and inhibitory neurons. Coupling between the local networks is introduced through sparsely distributed excitatory connectivity. Voltage- and ligand-gated ion channels determine the neural dynamics of the networks. The effect of electromagnetic field on the neural system is studied by modulating magnetic flux on the membrane potential using memristor coupling. With the application of electromagnetic field and the modulation of long-range synaptic coupling, the system easily makes transition to synchronization. It is found that the threshold for synchrony between coupled local networks is lowered by the applied electromagnetic field. Also, electromagnetic field causes the neural subsystems to make low amplitude oscillations with an approximate frequency of 130 Hz. This indicates that electromagnetic field gives rise to high-gamma activity in the cortical regions of the brain which increases selective attention. This may facilitate adaptive brain function by giving rise to a rich collection of dynamics and contribute to the origin of complex patterns observed in the EEG.

scholarly journals Whole-transcriptome RNA editing analysis in single cortical neurons links locus 15q11 with psychiatric illness

2019 ◽  
Author(s):  
Brendan Robert E. Ansell ◽  
Simon N. Thomas ◽  
Roberto Bonelli ◽  
Jacob E. Munro ◽  
Saskia Freytag ◽  
...  
Keyword(s):  
Rna Editing ◽  
Cortical Neurons ◽  
Serotonin Receptor ◽  
Target Genes ◽  
Linear Models ◽  
Inhibitory Neurons ◽  
Neuronal Nuclei ◽  
Neuropsychiatric Diseases ◽  
Excitatory Neurons ◽  
Cortical Regions

ABSTRACTBACKGROUNDConversion of adenosine to inosine in RNA by ADAR enzymes occurs at thousands of sites in the human transcriptome, and is essential for healthy brain development. This ‘RNA editing’ process is dysregulated in many neuropsychiatric diseases, but is little understood at the level of individual neurons.METHODSWe quantified RNA editing sites in full-length capture nuclear transcriptomes of 3055 neurons from six cortical regions of a neurotypical post-mortem female donor. Putative editing sites were intersected with sites in bulk human tissue transcriptomes including healthy and neuropsychiatric brain tissue, and sites identified in single nuclei from unrelated brain donors. Differential editing between cell types and cortical regions, and individual sites and genes therein, was quantified using linear models. Associations between gene expression and editing were also tested.RESULTSWe identified 41,930 RNA editing sites with robust read coverage in at least ten neuronal nuclei. Most sites were located within Alu repeats in introns or 3’ UTRs, and approximately 80% were catalogued in published RNA editing databases. We identified 9285 putative novel RNA editing sites, 29% of which were also detectable neuronal transcriptomes from unrelated donors. Inhibitory neurons showed higher overall transcriptome editing than excitatory neurons. Among the strongest correlates of global editing rates were snoRNAs from the SNORD115 and SNORD116 cluster (15q11), known to modulate serotonin receptor processing and to colocalize with ADAR2. We identified 29 genes preferentially edited in excitatory neurons and 44 genes edited more heavily in inhibitory neurons including RBFOX1, its target genes and small nucleolar RNA-associated genes in the autism-associated Prader-Willi locus 15q11. These results provide cell-type and spatial context for 1730 and 910 sites that are also edited in the brains of schizophrenic and autistic patients respectively, and a reference for future studies of RNA editing in single brain cells from these cohorts.CONCLUSIONSRNA editing, including thousands of previously unreported sites, is robustly detectable in single neuronal nuclei, where gene editing differences are stronger between cell subtypes than between cortical regions. Insufficient editing of ASD-related genes in inhibitory neurons may manifest in the specific perturbation of these cells in autism.

scholarly journals Implications of Extended Inhibitory Neuron Development

2021 ◽  
Vol 22 (10) ◽  
pp. 5113
Author(s):  
Jae-Yeon Kim ◽  
Mercedes F. Paredes
Keyword(s):  
Neural Circuit ◽  
Inhibitory Neuron ◽  
Postnatal Period ◽  
Specific Pattern ◽  
Inhibitory Neurons ◽  
Gabaergic Interneuron ◽  
Gabaergic Interneurons ◽  
Neuron Development ◽  
Cortical Regions ◽  
Circuit Formation

A prolonged developmental timeline for GABA (γ-aminobutyric acid)-expressing inhibitory neurons (GABAergic interneurons) is an amplified trait in larger, gyrencephalic animals. In several species, the generation, migration, and maturation of interneurons take place over several months, in some cases persisting after birth. The late integration of GABAergic interneurons occurs in a region-specific pattern, especially during the early postnatal period. These changes can contribute to the formation of functional connectivity and plasticity, especially in the cortical regions responsible for higher cognitive tasks. In this review, we discuss GABAergic interneuron development in the late gestational and postnatal forebrain. We propose the protracted development of interneurons at each stage (neurogenesis, neuronal migration, and network integration), as a mechanism for increased complexity and cognitive flexibility in larger, gyrencephalic brains. This developmental feature of interneurons also provides an avenue for environmental influences to shape neural circuit formation.

scholarly journals Direct electrical stimulation of human cortex evokes high gamma activity that predicts conscious somatosensory perception

2018 ◽  
Vol 15 (2) ◽  
pp. 026015 ◽  
Author(s):  
Leah Muller ◽  
John D Rolston ◽  
Neal P Fox ◽  
Robert Knowlton ◽  
Vikram R Rao ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Gamma Activity ◽  
Direct Electrical Stimulation ◽  
Human Cortex ◽  
High Gamma ◽  
Stimulation Of

Extracting Number-Selective Responses from Coherent Oscillations in a Computer Model

2007 ◽  
Vol 19 (7) ◽  
pp. 1766-1797 ◽  
Author(s):  
Jeremy A. Miller ◽  
Garrett T. Kenyon
Keyword(s):  
Cortical Neurons ◽  
Random Phase ◽  
Relative Size ◽  
Indirect Evidence ◽  
Gamma Activity ◽  
Total Power ◽  
Square Root ◽  
Tuning Curves ◽  
Critical Issues ◽  
Experimental Resolution

Cortical neurons selective for numerosity may underlie an innate number sense in both animals and humans. We hypothesize that the number- selective responses of cortical neurons may in part be extracted from coherent, object-specific oscillations . Here, indirect evidence for this hypothesis is obtained by analyzing the numerosity information encoded by coherent oscillations in artificially generated spikes trains. Several experiments report that gamma-band oscillations evoked by the same object remain coherent, whereas oscillations evoked by separate objects are uncorrelated. Because the oscillations arising from separate objects would add in random phase to the total power summed across all stimulated neurons, we postulated that the total gamma activity, normalized by the number of spikes, should fall roughly as the square root of the number of objects in the scene, thereby implicitly encoding numerosity. To test the hypothesis, we examined the normalized gamma activity in multiunit spike trains, 50 to 1000 msec in duration, produced by a model feedback circuit previously shown to generate realistic coherent oscillations. In response to images containing different numbers of objects, regardless of their shape, size, or shading, the normalized gamma activity followed a square-root-of-n rule as long as the separation between objects was sufficiently large and their relative size and contrast differences were not too great. Arrays of winner-take-all numerosity detectors, each responding to normalized gamma activity within a particular band, exhibited tuning curves consistent with behavioral data. We conclude that coherent oscillations in principle could contribute to the number-selective responses of cortical neurons, although many critical issues await experimental resolution.

scholarly journals Comparison of subdural and subgaleal recordings of cortical high-gamma activity in humans

2016 ◽  
Vol 127 (1) ◽  
pp. 277-284 ◽  
Author(s):  
Jared D. Olson ◽  
Jeremiah D. Wander ◽  
Lise Johnson ◽  
Devapratim Sarma ◽  
Kurt Weaver ◽  
...  
Keyword(s):  
Gamma Activity ◽  
High Gamma

scholarly journals Fast-spiking GABA circuit dynamics in the auditory cortex predict recovery of sensory processing following peripheral nerve damage

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Jennifer Resnik ◽  
Daniel B Polley
Keyword(s):  
Peripheral Nerve ◽  
Auditory Cortex ◽  
Sensory Processing ◽  
Cortical Neurons ◽  
Sensory Nerve ◽  
Intracortical Inhibition ◽  
Nerve Fibers ◽  
Nerve Damage ◽  
Inhibitory Neurons ◽  
Sound Processing

Cortical neurons remap their receptive fields and rescale sensitivity to spared peripheral inputs following sensory nerve damage. To address how these plasticity processes are coordinated over the course of functional recovery, we tracked receptive field reorganization, spontaneous activity, and response gain from individual principal neurons in the adult mouse auditory cortex over a 50-day period surrounding either moderate or massive auditory nerve damage. We related the day-by-day recovery of sound processing to dynamic changes in the strength of intracortical inhibition from parvalbumin-expressing (PV) inhibitory neurons. Whereas the status of brainstem-evoked potentials did not predict the recovery of sensory responses to surviving nerve fibers, homeostatic adjustments in PV-mediated inhibition during the first days following injury could predict the eventual recovery of cortical sound processing weeks later. These findings underscore the potential importance of self-regulated inhibitory dynamics for the restoration of sensory processing in excitatory neurons following peripheral nerve injuries.

scholarly journals Prefrontal High Gamma in ECoG tags periodicity of musical rhythms in perception and imagination

2019 ◽  
Author(s):  
S. A. Herff ◽  
C. Herff ◽  
A. J. Milne ◽  
G. D. Johnson ◽  
J. J. Shih ◽  
...  
Keyword(s):  
Auditory Processing ◽  
Right Hemisphere ◽  
Brain Activity ◽  
Activity Patterns ◽  
Superior Temporal Gyrus ◽  
Gamma Activity ◽  
Rhythm Perception ◽  
High Gamma ◽  
The Right ◽  
Musical Rhythms

AbstractRhythmic auditory stimuli are known to elicit matching activity patterns in neural populations. Furthermore, recent research has established the particular importance of high-gamma brain activity in auditory processing by showing its involvement in auditory phrase segmentation and envelope-tracking. Here, we use electrocorticographic (ECoG) recordings from eight human listeners, to see whether periodicities in high-gamma activity track the periodicities in the envelope of musical rhythms during rhythm perception and imagination. Rhythm imagination was elicited by instructing participants to imagine the rhythm to continue during pauses of several repetitions. To identify electrodes whose periodicities in high-gamma activity track the periodicities in the musical rhythms, we compute the correlation between the autocorrelations (ACC) of both the musical rhythms and the neural signals. A condition in which participants listened to white noise was used to establish a baseline. High-gamma autocorrelations in auditory areas in the superior temporal gyrus and in frontal areas on both hemispheres significantly matched the autocorrelation of the musical rhythms. Overall, numerous significant electrodes are observed on the right hemisphere. Of particular interest is a large cluster of electrodes in the right prefrontal cortex that is active during both rhythm perception and imagination. This indicates conscious processing of the rhythms’ structure as opposed to mere auditory phenomena. The ACC approach clearly highlights that high-gamma activity measured from cortical electrodes tracks both attended and imagined rhythms.

scholarly journals Synaptic Signals from Glutamate-Treated Neurons Induce Aberrant Post-Synaptic Signals in Untreated Neuronal Networks

2020 ◽  
Vol 14 (1) ◽  
pp. 59-62
Author(s):  
Mary Guaraldi ◽  
Sangmook Lee ◽  
Thomas B. Shea
Keyword(s):  
Cortical Neurons ◽  
Neuronal Networks ◽  
Synaptic Function ◽  
Glutamate Excitotoxicity ◽  
Synaptic Connectivity ◽  
Extracellular Glutamate ◽  
Glutamate Neurotoxicity ◽  
Wide Range ◽  
Cortical Regions

Background and Objective: Glutamate neurotoxicity is associated with a wide range of disorders and can impair synaptic function. Failure to clear extracellular glutamate fosters additional cycles and spread of regional hyperexcitation. Methods and Results: Using cultured murine cortical neurons, herein it is demonstrated that synaptic signals generated by cultures undergoing glutamate-induced hyperactivity can invoke similar effects in other cultures not exposed to elevated glutamate. Conclusion: Since sequential synaptic connectivity can encompass extensive cortical regions, this study presents a potential additional contributor to the spread of damage resulting from glutamate excitotoxicity and should be considered in attempts to mitigate neurodegeneration.

scholarly journals Spontaneous dynamics of neural networks in deep layers of prefrontal cortex

2017 ◽  
Vol 117 (4) ◽  
pp. 1581-1594 ◽  
Author(s):  
Andrew S. Blaeser ◽  
Barry W. Connors ◽  
Arto V. Nurmikko
Keyword(s):  
Prefrontal Cortex ◽  
Spontaneous Activity ◽  
Calcium Imaging ◽  
Cortical Neurons ◽  
Rhythmic Activity ◽  
Network Activity ◽  
Local Networks ◽  
Spatiotemporal Scale ◽  
Deep Layers ◽  
Delta Oscillations

Cortical systems maintain and process information through the sustained activation of recurrent local networks of neurons. Layer 5 is known to have a major role in generating the recurrent activation associated with these functions, but relatively little is known about its intrinsic dynamics at the mesoscopic level of large numbers of neighboring neurons. Using calcium imaging, we measured the spontaneous activity of networks of deep-layer medial prefrontal cortical neurons in an acute slice model. Inferring the simultaneous activity of tens of neighboring neurons, we found that while the majority showed only sporadic activity, a subset of neurons engaged in sustained delta frequency rhythmic activity. Spontaneous activity under baseline conditions was weakly correlated between pairs of neurons, and rhythmic neurons showed little coherence in their oscillations. However, we consistently observed brief bouts of highly synchronous activity that must be attributed to network activity. NMDA-mediated stimulation enhanced rhythmicity, synchrony, and correlation within these local networks. These results characterize spontaneous prefrontal activity at a previously unexplored spatiotemporal scale and suggest that medial prefrontal cortex can act as an intrinsic generator of delta oscillations. NEW & NOTEWORTHY Using calcium imaging and a novel analytic framework, we characterized the spontaneous and NMDA-evoked activity of layer 5 prefrontal cortex at a largely unexplored spatiotemporal scale. Our results suggest that the mPFC microcircuitry is capable of intrinsically generating delta oscillations and sustaining synchronized network activity that is potentially relevant for understanding its contribution to cognitive processes.

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