Analysis of a Signal Transmission in a Pair of Izhikevich Coupled Neurons

2020 ◽  
Vol 15 (04) ◽  
pp. 195-206
Author(s):  
David. H. Margarit ◽  
Marcela V. Reale ◽  
Ariel F. Scagliotti
Keyword(s):  
White Noise ◽  
Resting State ◽  
Signal Transmission ◽  
Electrical Potential ◽  
Signal Amplitude ◽  
Receptor Neuron ◽  
Neuron Models ◽  
The Relationship ◽  
The Brain ◽  
Izhikevich Model

Individual neuron models give a comprehensive explanation of the behavior of the electrical potential of cell membranes. These models were and are a source of constant analysis to understand the functioning of, mainly, the complexity of the brain. In this work, using the Izhikevich model, we propose, analyze and characterize the transmission of a signal between two neurons unidirectionally coupled. Two possible states were characterized (sub-threshold and over-threshold) depending on the values of the signal amplitude, as well also the relationship between the transmitted and received signal taking into account the coupling. Furthermore, the activation of the emitting neuron (its transition from a resting state to spiking state) and the transmission to the receptor neuron were analyzed by adding white noise to the system.

Chronic stress and brain-derived neurotrophic factor

2021 ◽  
Vol 19 (2) ◽  
pp. 19-27
Author(s):  
A. V. DUBOVAYA ◽  
◽  
S. Ya. IAROSHENKO ◽  
O. A. PRILUTSKAYA ◽  
◽  
...  
Keyword(s):  
Neurotrophic Factor ◽  
Signal Transmission ◽  
Active Agent ◽  
Brain Derived Neurotrophic Factor ◽  
Relationship Of ◽  
The Relationship ◽  
The Brain ◽  
Pituitary Adrenal Axis ◽  
Transmission Information ◽  
Class Representative

The article discusses the influence of stress on the development of nervous tissue, in particular, on the synthesis of neurotrophins (by the example of the brain-derived neurotrophic factor (BDNF), as the most studied class representative). The biological functions of BDNF are discussed as well as its influence on neuroplasticity and the mechanisms by which the protection of neurons is carried out. The article covers the relationship of the stress-implementing system (hypothalamic-pituitary-adrenal axis) and its main active agent (cortisol) with the BDNF synthesis system at its various levels: from the inhibition of mRNA formation to the mechanisms of postsynaptic signal transmission. Information is also provided on changes of BDNF levels due to the maternal deprivation. Epigenetic changes under the influence of glucocorticoids are also reported. However, it is not only glucocorticoids that alter the functioning of the neurotrophin system. The article provides examples of the reverse effect, enabling to consider neurotrophins as a substance with an anti-stress function. In conclusion, the authors give examples of activities that, according to research, can stimulate the synthesis of neurotrophic factor in the brain.

Functional connectivity and microstructural changes of the brain in primary Sjögren syndrome: the relationship with depression

2020 ◽  
Vol 61 (12) ◽  
pp. 1684-1694
Author(s):  
Artemis Andrianopoulou ◽  
Anastasia K Zikou ◽  
Loukas G Astrakas ◽  
Nafsika Gerolymatou ◽  
Vasileios Xydis ◽  
...  
Keyword(s):  
White Matter ◽  
Functional Connectivity ◽  
Resting State ◽  
Pulse Sequence ◽  
Sjogren Syndrome ◽  
White Matter Tracts ◽  
Microstructural Changes ◽  
Primary Sjögren Syndrome ◽  
The Relationship ◽  
The Brain

Background Fatigue and depression are among the most common manifestations of primary Sjögren syndrome (pSS), but information is lacking on the relationship with brain function and microstructural changes. Purpose To investigate microstructural changes and brain connectivity in pSS, and to evaluate their relationship with fatigue and depression. Material and Methods The study included 29 patients with pSS (mean age 61.2 ± 12.1 years; disease duration 10.5 ± 5.9 years) and 28 controls (mean age 58.4 ± 9.2 years). All the patients completed the Beck’s depression and Fatigue Assessment Scale questionnaires. The imaging protocol consisted of: (i) standard magnetic resonance imaging (MRI) pulse sequences (FLAIR, 3D T1W); (ii) a diffusion tensor imaging pulse sequence; and (iii) a resting state functional MRI pulse sequence. Resting state brain networks and maps of diffusion metrics were calculated and compared between patients and controls. Results Compared with the controls, the patients with pSS and depression showed increased axial, radial, and mean diffusivity and decreased fractional anisotropy; those without depression showed decreased axial diffusivity in major white matter tracts (superior longitudinal fasciculus, inferior longitudinal fasciculus, corticospinal tract, anterior thalamic radiation, inferior fronto-occipital fasciculus, cingulum, uncinate fasciculus, and forceps minor-major). Decreased brain activation in the sensorimotor network was observed in the patients with pSS compared with the controls. No correlation was found between fatigue and structural or functional changes of the brain. Conclusion pSS is associated with functional connectivity abnormalities of the somatosensory cortex and microstructural abnormalities in major white matter tracts, which are more pronounced in depression.

scholarly journals Individual alpha peak frequency is slower in schizophrenia and related to deficits in visual perception and cognition

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ian S. Ramsay ◽  
Peter Lynn ◽  
Brandon Schermitzler ◽  
Scott Sponheim
Keyword(s):  
Visual Perception ◽  
Visual Attention ◽  
Resting State ◽  
Peak Frequency ◽  
Attention Task ◽  
Eyes Closed ◽  
Global Cognition ◽  
The Relationship ◽  
The Brain ◽  
Alpha Peak

AbstractThe brain at rest generates cycles of electrical activity that have been shown to be abnormal in people with schizophrenia. The alpha rhythm (~ 10 Hz) is the dominant resting state electrical cycle and each person has a propensity toward a particular frequency of oscillation for this rhythm. This individual alpha peak frequency (IAPF) is hypothesized to be central to visual perceptual processes and may have downstream influences on cognitive functions such as attention, working memory, or problem solving. In the current study we sought to determine whether IAPF was slower in schizophrenia, and whether lower IAPF predicted deficits in visual perception and cognition that are often observed in schizophrenia. Eyes-closed resting state EEG activity, visual attention, and global cognitive functioning were assessed in individuals with schizophrenia (N = 104) and a group of healthy controls (N = 101). Compared to controls, the schizophrenia group showed slower IAPF and was associated with poorer discrimination of visual targets and nontargets on a computerized attention task, as well as impaired global cognition measured using neuropsychological tests across groups. Notably, disruptions in visual attention fully mediated the relationship between IAPF and global cognition across groups. The current findings demonstrate that slower alpha oscillatory cycling accounts for global cognitive deficits in schizophrenia by way of impairments in perceptual discrimination measured during a visual attention task.

scholarly journals Correspondence between resting state activity and brain gene expression

2015 ◽  
Author(s):  
Guang-Zhong Wang ◽  
T. Grant Belgard ◽  
Deng Mao ◽  
Leslie Chen ◽  
Stefano Berto ◽  
...  
Keyword(s):  
Gene Expression ◽  
Resting State ◽  
Brain Activity ◽  
Low Frequency ◽  
Population Level ◽  
Rna Seq ◽  
Brain Gene Expression ◽  
Functional Brain Activity ◽  
The Relationship ◽  
The Brain

The relationship between functional brain activity and gene expression has not been fully explored in the human brain. Here, we identify significant correlations between gene expression in the brain and functional activity by comparing fractional Amplitude of Low Frequency Fluctuations (fALFF) from two independent human fMRI resting state datasets to regional cortical gene expression from a newly generated RNA-seq dataset and two additional gene expression datasets to obtain robust and reproducible correlations. We find significantly more genes correlated with fALFF than expected by chance, and identify specific genes correlated with the imaging signals in multiple expression datasets in the default mode network. Together, these data support a population-level relationship between regional steady state brain gene expression and resting state brain activity.

Physical Fitness and Resting EEG in Children With Attention Deficit Hyperactivity Disorder

2015 ◽  
Vol 29 (1) ◽  
pp. 26-32 ◽  
Author(s):  
Ching-Wen Huang ◽  
Chung-Ju Huang ◽  
Chiao-Ling Hung ◽  
Chia-Hao Shih ◽  
Tsung-Min Hung
Keyword(s):  
Attention Deficit Hyperactivity Disorder ◽  
Physical Fitness ◽  
Attention Deficit ◽  
Resting State ◽  
Self Control ◽  
Children With Adhd ◽  
Hyperactivity Disorder ◽  
Higher Power ◽  
Eyes Open ◽  
The Relationship

Children with attention deficit hyperactivity disorder (ADHD) are characterized by a deviant pattern of brain oscillations during resting state, particularly elevated theta power and increased theta/alpha and theta/beta ratios that are related to cognitive functioning. Physical fitness has been found beneficial to cognitive performance in a wide age population. The purpose of the present study was to investigate the relationship between physical fitness and resting-state electroencephalographic (EEG) oscillations in children with ADHD. EEG was recorded during eyes-open resting for 28 children (23 boys and 5 girls, 8.66 ± 1.10 years) with ADHD, and a battery of physical fitness assessments including flexibility, muscular endurance, power, and agility tests were administered. The results indicated that ADHD children with higher power fitness exhibited a smaller theta/alpha ratio than those with lower power fitness. These findings suggest that power fitness may be associated with improved attentional self-control in children with ADHD.

Grenzenlose Verantwortung

2010 ◽  
Vol 2010 (1) ◽  
pp. 5-22
Author(s):  
Ralf Becker
Keyword(s):  
Personal Freedom ◽  
The Relationship ◽  
The Brain

The article examines the relationship between freedom, guilt and responsibility in Dostojewski’s and Sartre’s works. Both attribute a great measure of personal freedom to man. Therefore, they do not tolerate excuses. Whoever is free, carries responsibility and gets caught up in guilt. Dostojewski’s focus is mainly on guilt, Sartre’s is on responsibility. They share the conviction that we can delegate responsibility for our actions or our way of living neither to a whole, of which we are a part, like society (the ,milieu'), nor to a part, for which we are the whole, like the ,brain' or the ,genes'. In that sense, Dostojewski’s and Sartre’s attempts at an ethic of responsibility also offer convincing arguments against determinism.

EXPERIMENTAL ASSESSMENT OF THE NANOPARTICLES TOXICITY OF NICKEL OXIDE IN TWO SIZES IN THE SUBCHRONIC EXPERIMENT

2018 ◽  
pp. 30-35
Author(s):  
M.P. Sutunkova ◽  
B.A. Katsnelson ◽  
L.I. Privalova ◽  
S.N. Solovjeva ◽  
V.B. Gurvich ◽  
...  
Keyword(s):  
Nickel Oxide ◽  
Nervous Activity ◽  
Equal Mass ◽  
The Body ◽  
Subchronic Toxicity ◽  
Physiological Mechanisms ◽  
Nickel Oxide Nanoparticles ◽  
The Relationship ◽  
The Brain ◽  
Nanoparticles Toxicity

We conducted a comparative assessment of the nickel oxide nanoparticles toxicity (NiO) of two sizes (11 and 25 nm) according to a number of indicators of the body state after repeated intraperitoneal injections of these particles suspensions. At equal mass doses, NiO nanoparticles have been found to cause various manifestations of systemic subchronic toxicity with a particularly pronounced effect on liver, kidney function, the body’s antioxidant system, lipid metabolism, white and red blood, redox metabolism, spleen damage, and some disorders of nervous activity allegedly related to the possibility of nickel penetration into the brain from the blood. The relationship between the diameter and toxicity of particles is ambiguous, which may be due to differences in toxicokinetics, which is controlled by both physiological mechanisms and direct penetration of nanoparticles through biological barriers and, finally, unequal solubility.

Polymeric Nanoparticles for Brain Drug Delivery - A Review

2020 ◽  
Vol 21 (9) ◽  
pp. 649-660
Author(s):  
Subashini Raman ◽  
Syed Mahmood ◽  
Ayah R. Hilles ◽  
Md Noushad Javed ◽  
Motia Azmana ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Surface Modification ◽  
Polymeric Nanoparticles ◽  
Drug Loading ◽  
Preparation Methods ◽  
Brain Drug Delivery ◽  
Polymeric Nanoparticle ◽  
Relationship Of ◽  
The Relationship ◽  
The Brain

Background: Blood-brain barrier (BBB) plays a most hindering role in drug delivery to the brain. Recent research comes out with the nanoparticles approach, is continuously working towards improving the delivery to the brain. Currently, polymeric nanoparticle is extensively involved in many therapies for spatial and temporal targeted areas delivery. Methods: We did a non-systematic review, and the literature was searched in Google, Science Direct and PubMed. An overview is provided for the formulation of polymeric nanoparticles using different methods, effect of surface modification on the nanoparticle properties with types of polymeric nanoparticles and preparation methods. An account of different nanomedicine employed with therapeutic agent to cross the BBB alone with biodistribution of the drugs. Results: We found that various types of polymeric nanoparticle systems are available and they prosper in delivering the therapeutic amount of the drug to the targeted area. The effect of physicochemical properties on nanoformulation includes change in their size, shape, elasticity, surface charge and hydrophobicity. Surface modification of polymers or nanocarriers is also vital in the formulation of nanoparticles to enhance targeting efficiency to the brain. Conclusion: More standardized methods for the preparation of nanoparticles and to assess the relationship of surface modification on drug delivery. While the preparation and its output like drug loading, particle size, and charge, permeation is always conflicted, so it requires more attention for the acceptance of nanoparticles for brain delivery.

scholarly journals The relationship of morphometric changes of the brain with IL-6 levels, systemic inflammation and immune disturbances in the patients with schizophrenia

2021 ◽  
Vol 190 ◽  
pp. 553-559
Author(s):  
Irina K. Malashenkova ◽  
Vadim L. Ushakov ◽  
Sergey A. Krynskiy ◽  
Daniil P. Ogurtsov ◽  
Nikita A. Khailov ◽  
...  
Keyword(s):  
Systemic Inflammation ◽  
Relationship Of ◽  
The Relationship ◽  
The Brain

scholarly journals The unbalanced reorganization of weaker functional connections induces the altered brain network topology in schizophrenia

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rossana Mastrandrea ◽  
Fabrizio Piras ◽  
Andrea Gabrielli ◽  
Nerisa Banaj ◽  
Guido Caldarelli ◽  
...  
Keyword(s):  
Resting State ◽  
Functional Organization ◽  
Functional Integration ◽  
Brain Network ◽  
Modular Organization ◽  
Node Degree ◽  
Imaging Data ◽  
Brain Disorder ◽  
Functional Connections ◽  
The Brain

AbstractNetwork neuroscience shed some light on the functional and structural modifications occurring to the brain associated with the phenomenology of schizophrenia. In particular, resting-state functional networks have helped our understanding of the illness by highlighting the global and local alterations within the cerebral organization. We investigated the robustness of the brain functional architecture in 44 medicated schizophrenic patients and 40 healthy comparators through an advanced network analysis of resting-state functional magnetic resonance imaging data. The networks in patients showed more resistance to disconnection than in healthy controls, with an evident discrepancy between the two groups in the node degree distribution computed along a percolation process. Despite a substantial similarity of the basal functional organization between the two groups, the expected hierarchy of healthy brains' modular organization is crumbled in schizophrenia, showing a peculiar arrangement of the functional connections, characterized by several topologically equivalent backbones. Thus, the manifold nature of the functional organization’s basal scheme, together with its altered hierarchical modularity, may be crucial in the pathogenesis of schizophrenia. This result fits the disconnection hypothesis that describes schizophrenia as a brain disorder characterized by an abnormal functional integration among brain regions.

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