WorldWideScience

Sample records for brain signal complexity

  1. Brain signal complexity rises with repetition suppression in visual learning.

    Science.gov (United States)

    Lafontaine, Marc Philippe; Lacourse, Karine; Lina, Jean-Marc; McIntosh, Anthony R; Gosselin, Frédéric; Théoret, Hugo; Lippé, Sarah

    2016-06-21

    Neuronal activity associated with visual processing of an unfamiliar face gradually diminishes when it is viewed repeatedly. This process, known as repetition suppression (RS), is involved in the acquisition of familiarity. Current models suggest that RS results from interactions between visual information processing areas located in the occipito-temporal cortex and higher order areas, such as the dorsolateral prefrontal cortex (DLPFC). Brain signal complexity, which reflects information dynamics of cortical networks, has been shown to increase as unfamiliar faces become familiar. However, the complementarity of RS and increases in brain signal complexity have yet to be demonstrated within the same measurements. We hypothesized that RS and brain signal complexity increase occur simultaneously during learning of unfamiliar faces. Further, we expected alteration of DLPFC function by transcranial direct current stimulation (tDCS) to modulate RS and brain signal complexity over the occipito-temporal cortex. Participants underwent three tDCS conditions in random order: right anodal/left cathodal, right cathodal/left anodal and sham. Following tDCS, participants learned unfamiliar faces, while an electroencephalogram (EEG) was recorded. Results revealed RS over occipito-temporal electrode sites during learning, reflected by a decrease in signal energy, a measure of amplitude. Simultaneously, as signal energy decreased, brain signal complexity, as estimated with multiscale entropy (MSE), increased. In addition, prefrontal tDCS modulated brain signal complexity over the right occipito-temporal cortex during the first presentation of faces. These results suggest that although RS may reflect a brain mechanism essential to learning, complementary processes reflected by increases in brain signal complexity, may be instrumental in the acquisition of novel visual information. Such processes likely involve long-range coordinated activity between prefrontal and lower order visual

  2. Differential maturation of brain signal complexity in the human auditory and visual system

    Directory of Open Access Journals (Sweden)

    Sarah Lippe

    2009-11-01

    Full Text Available Brain development carries with it a large number of structural changes at the local level which impact on the functional interactions of distributed neuronal networks for perceptual processing. Such changes enhance information processing capacity, which can be indexed by estimation of neural signal complexity. Here, we show that during development, EEG signal complexity increases from one month to 5 years of age in response to auditory and visual stimulation. However, the rates of change in complexity were not equivalent for the two responses. Infants’ signal complexity for the visual condition was greater than auditory signal complexity, whereas adults showed the same level of complexity to both types of stimuli. The differential rates of complexity change may reflect a combination of innate and experiential factors on the structure and function of the two sensory systems.

  3. Differential maturation of brain signal complexity in the human auditory and visual system

    OpenAIRE

    Sarah Lippe; Randy McIntosh

    2009-01-01

    Brain development carries with it a large number of structural changes at the local level which impact on the functional interactions of distributed neuronal networks for perceptual processing. Such changes enhance information processing capacity, which can be indexed by estimation of neural signal complexity. Here, we show that during development, EEG signal complexity increases from one month to 5 years of age in response to auditory and visual stimulation. However, the rates of change in...

  4. Differential Maturation of Brain Signal Complexity in the Human Auditory and Visual System

    OpenAIRE

    Lippé, Sarah; Kovacevic, Natasa; McIntosh, Anthony Randal

    2009-01-01

    Brain development carries with it a large number of structural changes at the local level which impact on the functional interactions of distributed neuronal networks for perceptual processing. Such changes enhance information processing capacity, which can be indexed by estimation of neural signal complexity. Here, we show that during development, EEG signal complexity increases from one month to 5 years of age in response to auditory and visual stimulation. However, the rates of change in c...

  5. Analysis and simulation of brain signal data by EEG signal processing technique using MATLAB

    OpenAIRE

    Sasikumar Gurumurthy; Vudi Sai Mahit; Rittwika Ghosh

    2013-01-01

    EEG is brain signal processing technique that allows gaining the understanding of the complex inner mechanisms of the brain and abnormal brain waves have shown to be associated with particular brain disorders. The analysis of brain waves plays an important role in diagnosis of different brain disorders. MATLAB provides an interactive graphic user interface (GUI) allowing users to flexiblyand interactively process their high-density EEG dataset and other brain signal data different techniques ...

  6. Analysis and simulation of brain signal data by EEG signal processing technique using MATLAB

    Directory of Open Access Journals (Sweden)

    Sasikumar Gurumurthy

    2013-06-01

    Full Text Available EEG is brain signal processing technique that allows gaining the understanding of the complex inner mechanisms of the brain and abnormal brain waves have shown to be associated with particular brain disorders. The analysis of brain waves plays an important role in diagnosis of different brain disorders. MATLAB provides an interactive graphic user interface (GUI allowing users to flexiblyand interactively process their high-density EEG dataset and other brain signal data different techniques such as independent component analysis (ICA and/or time/frequency analysis (TFA, as well as standard averaging methods. We will be showing different brain signals by comparing, analysing and simulating datasets which is already loaded in the MATLAB software to process the EEG signals.

  7. Notch Signaling and Brain Tumors

    DEFF Research Database (Denmark)

    Stockhausen, Marie; Kristoffersen, Karina; Poulsen, Hans Skovgaard

    2011-01-01

    Human brain tumors are a heterogenous group of neoplasms occurring inside the cranium and the central spinal cord. In adults and children, astrocytic glioma and medulloblastoma are the most common subtypes of primary brain tumors. These tumor types are thought to arise from cells in which Notch...

  8. Cetaceans Have Complex Brains for Complex Cognition

    OpenAIRE

    Marino, Lori; Connor, Richard C.; Fordyce, R. Ewan; Herman, Louis M; Hof, Patrick R.; Lefebvre, Louis; Lusseau, David; Mccowan, Brenda; Nimchinsky, Esther A.; Pack, Adam A.; Rendell, Luke; Joy S Reidenberg; Reiss, Diana; Uhen, Mark D.; Van der Gucht, Estel

    2007-01-01

    The brain of a sperm whale is about 60% larger in absolute mass than that of an elephant. Furthermore, the brains of toothed whales and dolphins are significantly larger than those of any nonhuman primates and are second only to human brains when measured with respect to body size. How and why did such large brains evolve in these modern cetaceans? One current view of the evolution of dolphin brains is that their large size was primarily a response to social forces—the requirements for effect...

  9. Phylogenetic signal, feeding behaviour and brain volume in Neotropical bats.

    Science.gov (United States)

    Rojas, D; Mancina, C A; Flores-Martínez, J J; Navarro, L

    2013-09-01

    Comparative correlational studies of brain size and ecological traits (e.g. feeding habits and habitat complexity) have increased our knowledge about the selective pressures on brain evolution. Studies conducted in bats as a model system assume that shared evolutionary history has a maximum effect on the traits. However, this effect has not been quantified. In addition, the effect of levels of diet specialization on brain size remains unclear. We examined the role of diet on the evolution of brain size in Mormoopidae and Phyllostomidae using two comparative methods. Body mass explained 89% of the variance in brain volume. The effect of feeding behaviour (either characterized as feeding habits, as levels of specialization on a type of item or as handling behaviour) on brain volume was also significant albeit not consistent after controlling for body mass and the strength of the phylogenetic signal (λ). Although the strength of the phylogenetic signal of brain volume and body mass was high when tested individually, λ values in phylogenetic generalized least squares models were significantly different from 1. This suggests that phylogenetic independent contrasts models are not always the best approach for the study of ecological correlates of brain size in New World bats. PMID:23944375

  10. Integrating Retinoic Acid Signaling with Brain Function

    Science.gov (United States)

    Luo, Tuanlian; Wagner, Elisabeth; Drager, Ursula C.

    2009-01-01

    The vitamin A derivative retinoic acid (RA) regulates the transcription of about a 6th of the human genome. Compelling evidence indicates a role of RA in cognitive activities, but its integration with the molecular mechanisms of higher brain functions is not known. Here we describe the properties of RA signaling in the mouse, which point to…

  11. Lactate transport and signaling in the brain

    DEFF Research Database (Denmark)

    Bergersen, Linda Hildegard

    2015-01-01

    Lactate acts as a ‘buffer’ between glycolysis and oxidative metabolism. In addition to being exchanged as a fuel by the monocarboxylate transporters (MCTs) between cells and tissues with different glycolytic and oxidative rates, lactate may be a ‘volume transmitter’ of brain signals. According to...

  12. Obesity-Induced Hypertension: Brain Signaling Pathways.

    Science.gov (United States)

    do Carmo, Jussara M; da Silva, Alexandre A; Wang, Zhen; Fang, Taolin; Aberdein, Nicola; de Lara Rodriguez, Cecilia E P; Hall, John E

    2016-07-01

    Obesity greatly increases the risk for cardiovascular, metabolic, and renal diseases and is one of the most significant and preventable causes of increased blood pressure (BP) in patients with essential hypertension. This review highlights recent advances in our understanding of central nervous system (CNS) signaling pathways that contribute to the etiology and pathogenesis of obesity-induced hypertension. We discuss the role of excess adiposity and activation of the brain leptin-melanocortin system in causing increased sympathetic activity in obesity. In addition, we highlight other potential brain mechanisms by which increased weight gain modulates metabolic and cardiovascular functions. Unraveling the CNS mechanisms responsible for increased sympathetic activation and hypertension and how circulating hormones activate brain signaling pathways to control BP offer potentially important therapeutic targets for obesity and hypertension. PMID:27262997

  13. Passive Hindrances Suppression Using Complex Polyphase Signals

    OpenAIRE

    Sumyk, Markiyan; Yankevych, Roman

    2010-01-01

    Using complex signals we get possibility of indemnification of passive hindrances in the single-channel system of radio monitoring due to the use of correlation and spectral characteristics of certain class of complex signals.

  14. Model human heart or brain signals

    OpenAIRE

    Tuncay, Caglar

    2008-01-01

    A new model is suggested and used to mimic various spatial or temporal designs in biological or non biological formations where the focus is on the normal or irregular electrical signals coming from human heart (ECG) or brain (EEG). The electrical activities in several muscles (EMG) or neurons or other organs of human or various animals, such as lobster pyloric neuron, guinea pig inferior olivary neuron, sepia giant axon and mouse neocortical pyramidal neuron and some spatial formations are a...

  15. Progesterone signaling mechanisms in brain and behavior

    Directory of Open Access Journals (Sweden)

    ShailaMani

    2012-01-01

    Full Text Available Steroid hormone, progesterone, modulates neuroendocrine functions in the central nervous system resulting in alterations in physiology and behavior. These neuronal effects are mediated primarily by intracellular progestin receptors in the steroid-sensitive neurons, resulting in transcription-dependent genomic actions (classical mechanism. In addition to progesterone, intracellular progestin receptors can also be activated in a “ligand-independent” manner by neurotransmitters, peptide growth factors, cyclic nucleotides and neurosteroids. Recent studies indicate that rapid, non-classical progesterone actions involving cytoplasmic kinase signaling and/or extranuclear progestin receptors can result in both transcription-independent and transcription-dependent actions. Cross-talk between extranuclear and classical intracellular signaling pathways promotes progesterone-dependent behavior in mammals. This review focuses on the mechanisms by which progesterone-initiated signaling mechanisms converge with progestin receptors in the brain to modulate reproductive behavior in female rodents.

  16. Identifying modular relations in complex brain networks

    DEFF Research Database (Denmark)

    Andersen, Kasper Winther; Mørup, Morten; Siebner, Hartwig; Madsen, Kristoffer H.; Hansen, Lars Kai

    2012-01-01

    We evaluate the infinite relational model (IRM) against two simpler alternative nonparametric Bayesian models for identifying structures in multi subject brain networks. The models are evaluated for their ability to predict new data and infer reproducible structures. Prediction and reproducibility...... overfit and obtains comparable reproducibility and predictability. For resting state functional magnetic resonance imaging data from 30 healthy controls the IRM model is also superior to the two simpler alternatives, suggesting that brain networks indeed exhibit universal complex relational structure in...

  17. The Brain Fingerprinting Through Digital Electroencephalography Signal Technique

    Directory of Open Access Journals (Sweden)

    Dinesh Chandra Jain,

    2011-03-01

    Full Text Available A brain computer interaction has been developed to record the brain signal / electric activity through Digital Electroencephalography. The Brain Fingerprinting is a advanced computer-based technology to etermine the falsely accused innocent suspects of a crime accurately and scientifically by measuring brain-wave responses to crime-relevant words or pictures presented on a computer screen. By using lectroencephalography to ascertain the presence or absence of information into human brain.

  18. Model human heart or brain signals

    CERN Document Server

    Tuncay, Caglar

    2008-01-01

    A new model is suggested and used to mimic various spatial or temporal designs in biological or non biological formations where the focus is on the normal or irregular electrical signals coming from human heart (ECG) or brain (EEG). The electrical activities in several muscles (EMG) or neurons or other organs of human or various animals, such as lobster pyloric neuron, guinea pig inferior olivary neuron, sepia giant axon and mouse neocortical pyramidal neuron and some spatial formations are also considered (in Appendix). In the biological applications, several elements (cells or tissues) in an organ are taken as various entries in a representative lattice (mesh) where the entries are connected to each other in terms of some molecular diffusions or electrical potential differences. The biological elements evolve in time (with the given tissue or organ) in terms of the mentioned connections (interactions) besides some individual feedings. The anatomical diversity of the species (or organs) is handled in terms o...

  19. Complex bioimpedance signals in cardiology

    Czech Academy of Sciences Publication Activity Database

    Viščor, Ivo; Halámek, Josef; Vondra, Vlastimil

    Milano: Fondazione Don Carlo Gnocchi, 2008, P1B: 14-16. [Conference of the European Study Group on Cardiovascular Oscillations /5./ - ESGCO 2008. Parma (IT), 07.04.2008-09.04.2008] R&D Projects: GA ČR GP102/07/P425; GA AV ČR IAA200650801 Institutional research plan: CEZ:AV0Z20650511 Keywords : bioimpedance * complex impedance * impedance phase * cardiac output * pulmonary artery Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  20. QRS Complex Detection in Multilead ECG Signals

    OpenAIRE

    Šlancar, M.

    2015-01-01

    Automated analysis of HRV requires reliable detection of QRS complexes. We propose a detection method based on different combinations of three orthogonal (pseudoorthogonal) leads of human ECG signals. ECG signals were filtered by standard pass-band filter, Teager-Kaiser energy operator (TKEO) was applied on signal as envelope for detection. The most effective combination for QRS detection was a spatial velocity with sensitivity exceeds 99.9 % and positive predictive value near to 99.5 %. Det...

  1. Artifact suppression and analysis of brain activities with electroencephalography signals

    OpenAIRE

    Rashed-Al-Mahfuz, Md.; Islam, Md. Rabiul; Hirose, Keikichi; Molla, Md. Khademul Islam

    2013-01-01

    Brain-computer interface is a communication system that connects the brain with computer (or other devices) but is not dependent on the normal output of the brain (i.e., peripheral nerve and muscle). Electro-oculogram is a dominant artifact which has a significant negative influence on further analysis of real electroencephalography data. This paper presented a data adaptive technique for artifact suppression and brain wave extraction from electroencephalography signals to detect regional bra...

  2. Enhanced brain signal variability in children with autism spectrum disorder during early childhood.

    Science.gov (United States)

    Takahashi, Tetsuya; Yoshimura, Yuko; Hiraishi, Hirotoshi; Hasegawa, Chiaki; Munesue, Toshio; Higashida, Haruhiro; Minabe, Yoshio; Kikuchi, Mitsuru

    2016-03-01

    Extensive evidence shows that a core neurobiological mechanism of autism spectrum disorder (ASD) involves aberrant neural connectivity. Recent advances in the investigation of brain signal variability have yielded important information about neural network mechanisms. That information has been applied fruitfully to the assessment of aging and mental disorders. Multiscale entropy (MSE) analysis can characterize the complexity inherent in brain signal dynamics over multiple temporal scales in the dynamics of neural networks. For this investigation, we sought to characterize the magnetoencephalography (MEG) signal variability during free watching of videos without sound using MSE in 43 children with ASD and 72 typically developing controls (TD), emphasizing early childhood to older childhood: a critical period of neural network maturation. Results revealed an age-related increase of brain signal variability in a specific timescale in TD children, whereas atypical age-related alteration was observed in the ASD group. Additionally, enhanced brain signal variability was observed in children with ASD, and was confirmed particularly for younger children. In the ASD group, symptom severity was associated region-specifically and timescale-specifically with reduced brain signal variability. These results agree well with a recently reported theory of increased brain signal variability during development and aberrant neural connectivity in ASD, especially during early childhood. Results of this study suggest that MSE analytic method might serve as a useful approach for characterizing neurophysiological mechanisms of typical-developing and its alterations in ASD through the detection of MEG signal variability at multiple timescales. PMID:26859309

  3. Immune System to Brain Signaling: Neuropsychopharmacological Implications

    OpenAIRE

    Capuron, Lucile; Miller, Andrew H.

    2011-01-01

    There has been an explosion in our knowledge of the pathways and mechanisms by which the immune system can influence the brain and behavior. In the context of inflammation, pro-inflammatory cytokines can access the central nervous system and interact with a cytokine network in the brain to influence virtually every aspect of brain function relevant to behavior including neurotransmitter metabolism, neuroendocrine function, synaptic plasticity, and neurocircuits that regulate mood, motor activ...

  4. Complex networks in brain electrical activity

    CERN Document Server

    Ruffini, G; Grau, C; Marco, J; Ray, C

    2005-01-01

    We analyze the complex networks associated with brain electrical activity. Multichannel EEG measurements are first processed to obtain 3D voxel activations using the tomographic algorithm LORETA. Then, the correlation of the current intensity activation between voxel pairs is computed to produce a voxel cross-correlation coefficient matrix. Using several correlation thresholds, the cross-correlation matrix is then transformed into a network connectivity matrix and analyzed. To study a specific example, we selected data from an earlier experiment focusing on the MMN brain wave. The resulting analysis highlights significant differences between the spatial activations associated with Standard and Deviant tones, with interesting physiological implications. When compared to random data networks, physiological networks are more connected, with longer links and shorter path lengths. Furthermore, as compared to the Deviant case, Standard data networks are more connected, with longer links and shorter path lengths--i....

  5. Long-distance retinoid signaling in the zebra finch brain.

    Directory of Open Access Journals (Sweden)

    Tina C Roeske

    Full Text Available All-trans retinoic acid (ATRA, the main active metabolite of vitamin A, is a powerful signaling molecule that regulates large-scale morphogenetic processes during vertebrate embryonic development, but is also involved post-natally in regulating neural plasticity and cognition. In songbirds, it plays an important role in the maturation of learned song. The distribution of the ATRA-synthesizing enzyme, zRalDH, and of ATRA receptors (RARs have been described, but information on the distribution of other components of the retinoid signaling pathway is still lacking. To address this gap, we have determined the expression patterns of two obligatory RAR co-receptors, the retinoid X receptors (RXR α and γ, and of the three ATRA-degrading cytochromes CYP26A1, CYP26B1, and CYP26C1. We have also studied the distribution of zRalDH protein using immunohistochemistry, and generated a refined map of ATRA localization, using a modified reporter cell assay to examine entire brain sections. Our results show that (1 ATRA is more broadly distributed in the brain than previously predicted by the spatially restricted distribution of zRalDH transcripts. This could be due to long-range transport of zRalDH enzyme between different nuclei of the song system: Experimental lesions of putative zRalDH peptide source regions diminish ATRA-induced transcription in target regions. (2 Four telencephalic song nuclei express different and specific subsets of retinoid-related receptors and could be targets of retinoid regulation; in the case of the lateral magnocellular nucleus of the anterior nidopallium (lMAN, receptor expression is dynamically regulated in a circadian and age-dependent manner. (3 High-order auditory areas exhibit a complex distribution of transcripts representing ATRA synthesizing and degrading enzymes and could also be a target of retinoid signaling. Together, our survey across multiple connected song nuclei and auditory brain regions underscores the

  6. Cetacean Brain Evolution: Multiplication Generates Complexity

    OpenAIRE

    Marino, Lori

    2004-01-01

    Over the past 55-60 million years cetacean (dolphin, whale, and porpoise) brains have become hyperexpanded so that modern cetacean encephalization levels are second only to modern humans. At the same time, brain expansion proceeded along very different lines than in other large-brained mammals so that substantial differences between modern cetacean brains and other mammalian brains exist at every level of brain organization. Perhaps the most profound difference between cetacean and other mamm...

  7. Correlations between the Signal Complexity of Cerebral and Cardiac Electrical Activity: A Multiscale Entropy Analysis

    OpenAIRE

    Pei-Feng Lin; Men-Tzung Lo; Jenho Tsao; Yi-Chung Chang; Chen Lin; Yi-Lwun Ho

    2014-01-01

    The heart begins to beat before the brain is formed. Whether conventional hierarchical central commands sent by the brain to the heart alone explain all the interplay between these two organs should be reconsidered. Here, we demonstrate correlations between the signal complexity of brain and cardiac activity. Eighty-seven geriatric outpatients with healthy hearts and varied cognitive abilities each provided a 24-hour electrocardiography (ECG) and a 19-channel eye-closed routine electroencepha...

  8. Investigating phase synchronisation in EEG signals for brain connectivity analysis

    OpenAIRE

    Jamal, Wasifa

    2015-01-01

    The brain holds key information regarding the information processing capability of individuals and recent advances in sensor devices and technology have attracted researchers to question the working of this complex organ. It is not only the elusiveness of the brain that has drawn recent research attention but also the claim of doctors that brain function is key in neurological disorders. Disorders like Autism and Attention Deficit Hyperactivity Disorder (ADHD) not to mention other forms of ne...

  9. Artifact suppression and analysis of brain activities with electroencephalography signals

    Institute of Scientific and Technical Information of China (English)

    Md. Rashed-Al-Mahfuz; Md. Rabiul Islam; Keikichi Hirose; Md. Khademul Islam Molla

    2013-01-01

    Brain-computer interface is a communication system that connects the brain with computer (or other devices) but is not dependent on the normal output of the brain (i.e., peripheral nerve and muscle). Electro-oculogram is a dominant artifact which has a significant negative influence on further analysis of real electroencephalography data. This paper presented a data adaptive technique for artifact suppression and brain wave extraction from electroencephalography signals to detect regional brain activities. Empirical mode decomposition based adaptive thresholding approach was employed here to suppress the electro-oculogram artifact. Fractional Gaussian noise was used to determine the threshold level derived from the analysis data without any training. The purified electroencephalography signal was composed of the brain waves also called rhythmic components which represent the brain activities. The rhythmic components were extracted from each electroencephalography channel using adaptive wiener filter with the original scale. The regional brain activities were mapped on the basis of the spatial distribution of rhythmic components, and the results showed that different regions of the brain are activated in response to different stimuli. This research analyzed the activities of a single rhythmic component, alpha with respect to different motor imaginations. The experimental results showed that the proposed method is very efficient in artifact suppression and identifying individual motor imagery based on the activities of alpha component.

  10. Estimating Neural Signal Dynamics in the Human Brain

    Directory of Open Access Journals (Sweden)

    Christopher W Tyler

    2011-06-01

    Full Text Available Although brain imaging methods are highly effective for localizing the effects of neural activation throughout the human brain in terms of the blood oxygenation level dependent (BOLD response, there is currently no way to estimate the underlying neural signal dynamics in generating the BOLD response in each local activation region (except for processes slower than the BOLD time course. Knowledge of the neural signal is critical information if spatial mapping is to progress to the analysis of dynamic information flow through the cortical networks as the brain performs its tasks. We introduce an analytic approach that provides a new level of conceptualization and specificity in the study of brain processing by noninvasive methods. This technique allows us to use brain imaging methods to determine the dynamics of local neural population responses to their native temporal resolution throughout the human brain, with relatively narrow confidence intervals on many response properties. The ability to characterize local neural dynamics in the human brain represents a significant enhancement of brain imaging capabilities, with potential application from general cognitive studies to assessment of neuropathologies.

  11. Moment-to-moment brain signal variability: A next frontier in human brain mapping?

    OpenAIRE

    Garrett, D.; Samanez-Larkin, G.; MacDonald, S; Lindenberger, U; McIntosh, A.; Grady, C.

    2013-01-01

    Neuroscientists have long observed that brain activity is naturally variable from moment-to-moment, but neuroimaging research has largely ignored the potential importance of this phenomenon. An emerging research focus on within-person brain signal variability is providing novel insights, and offering highly predictive, complementary, and even orthogonal views of brain function in relation to human life-span development, cognitive performance, and various clinical conditions. As a result, brai...

  12. Complex analytic signals applied on time delay estimation

    OpenAIRE

    Veličković Zoran S.; Pavlović Vlastimir D.

    2008-01-01

    In this paper, we present the concept of the time delay estimation based on the transformation of real sensor signals into analytic ones. We analyze the differential time delay values obtained using real seismic signals, simulated complex analytic signals and simulated complex analytic signals with real parts coming from real seismic signals. The simulation results indicate that the application of complex analytic signals leads to reliable computation of the differential time delay. The influ...

  13. Predictive brain signals of linguistic development

    Directory of Open Access Journals (Sweden)

    Valesca eKooijman

    2013-02-01

    Full Text Available The ability to extract word forms from continuous speech is a prerequisite for constructing a vocabulary and emerges in the first year of life. Electrophysiological (ERP studies of speech segmentation by nine- to 12-month-old listeners in several languages have found a left-localized negativity linked to word onset as a marker of word detection. We report an ERP study showing significant evidence of speech segmentation in Dutch-learning seven-month-olds. In contrast to the left-localized negative effect reported with older infants, the observed overall mean effect had a positive polarity. Inspection of individual results revealed two participant sub-groups: a majority showing a positive-going response, and a minority showing the left negativity observed in older age groups. We retested participants at age three, on vocabulary comprehension and word and sentence production. On every test, children who at seven months had shown the negativity associated with segmentation of words from speech outperformed those who had produced positive-going brain responses to the same input. The earlier that infants show the left-localized brain responses typically indicating detection of words in speech, the better their early childhood language skills.

  14. Approach of Complex Networks for the Determination of Brain Death

    Institute of Scientific and Technical Information of China (English)

    SUN Wei-Gang; CAO Jian-Ting; WANG Ru-Bin

    2011-01-01

    In clinical practice, brain death is the irreversible end of all brain activity. Compared to current statistical methods for the determination of brain death, we focus on the approach of complex networks for real-world electroencephalography in its determination. Brain functional networks constructed by correlation analysis are derived, and statistical network quantities used for distinguishing the patients in coma or brain death state, such as average strength, clustering coefficient and average path length, are calculated. Numerical results show that the values of network quantities of patients in coma state are larger than those of patients in brain death state. Our Sndings might provide valuable insights on the determination of brain death.%@@ In clinical practice, brain death is the irreversible end of all brain activity.Compared to current statistical methods for the determination of brain death, we focus on the approach of complex networks for real-world electroencephalography in its determination.Brain functional networks constructed by correlation analysis axe derived, and statistical network quantities used for distinguishing the patients in coma or brain death state, such as average strength, clustering coefficient and average path length, are calculated.Numerical results show that the values of network quantities of patients in coma state are larger than those of patients in brain death state.Our findings might provide valuable insights on the determination of brain death.

  15. Tutorial: Signal Processing in Brain-Computer Interfaces

    NARCIS (Netherlands)

    Garcia Molina, G.

    2010-01-01

    Research in Electroencephalogram (EEG) based Brain-Computer Interfaces (BCIs) has been considerably expanding during the last few years. Such an expansion owes to a large extent to the multidisciplinary and challenging nature of BCI research. Signal processing undoubtedly constitutes an essential co

  16. Preliminary study of Alzheimer's Disease diagnosis based on brain electrical signals using wireless EEG

    Science.gov (United States)

    Handayani, N.; Akbar, Y.; Khotimah, S. N.; Haryanto, F.; Arif, I.; Taruno, W. P.

    2016-03-01

    This research aims to study brain's electrical signals recorded using EEG as a basis for the diagnosis of patients with Alzheimer's Disease (AD). The subjects consisted of patients with AD, and normal subjects are used as the control. Brain signals are recorded for 3 minutes in a relaxed condition and with eyes closed. The data is processed using power spectral analysis, brain mapping and chaos test to observe the level of complexity of EEG's data. The results show a shift in the power spectral in the low frequency band (delta and theta) in AD patients. The increase of delta and theta occurs in lobus frontal area and lobus parietal respectively. However, there is a decrease of alpha activity in AD patients where in the case of normal subjects with relaxed condition, brain alpha wave dominates the posterior area. This is confirmed by the results of brain mapping. While the results of chaos analysis show that the average value of MMLE is lower in AD patients than in normal subjects. The level of chaos associated with neural complexity in AD patients with lower neural complexity is due to neuronal damage caused by the beta amyloid plaques and tau protein in neurons.

  17. Natural brain-information interfaces: Recommending information by relevance inferred from human brain signals

    OpenAIRE

    Eugster, Manuel J. A.; Ruotsalo, Tuukka; Spapé, Michiel M.; Barral, Oswald; Ravaja, Niklas; Jacucci, Giulio; Kaski, Samuel

    2016-01-01

    Finding relevant information from large document collections such as the World Wide Web is a common task in our daily lives. Estimation of a user's interest or search intention is necessary to recommend and retrieve relevant information from these collections. We introduce a brain-information interface used for recommending information by relevance inferred directly from brain signals. In experiments, participants were asked to read Wikipedia documents about a selection of topics while their ...

  18. Development and evaluation of vinpocetine inclusion complex for brain targeting

    Directory of Open Access Journals (Sweden)

    Jiaojiao Ding

    2015-04-01

    Full Text Available The objective of this paper is to prepare vinpocetine (VIN inclusion complex and evaluate its brain targeting effect after intranasal administration. In the present study, VIN inclusion complex was prepared in order to increase its solubility. Stability constant (Kc was used for host selection. Factors influencing properties of the inclusion complex was investigated. Formation of the inclusion complex was identified by solubility study and DSC analysis. The brain targeting effect of the complex after intranasal administration was studied in rats. It was demonstrated that properties of the inclusion complex was mainly influenced by cyclodextrin type, organic acids type, system pH and host/guest molar ratio. Multiple component complexes can be formed by the addition of citric acid, with solubility improved for more than 23 times. Furthermore, In vivo study revealed that after intranasal administration, the absolute bioavailability of vinpocetine inclusion complex was 88%. Compared with intravenous injection, significant brain targeting effect was achieved after intranasal delivery, with brain targeting index 1.67. In conclusion, by intranasal administration of VIN inclusion complex, a fast onset of action and good brain targeting effect can be achieved. Intranasal route is a promising approach for the treatment of CNS diseases.

  19. Smart System to Recognize EEG Signal for Finding Brain Diseases Using K-Means Clustering

    Directory of Open Access Journals (Sweden)

    K.Gomathi

    2013-12-01

    Full Text Available In this paper, we are providing a research ideology, in which analysis of the EEG signal is done using an intelligent system in order to detect the brain diseases such as Epilepsy, Alzheimer’s disease etc. Here we are supposed to use clustering algorithm called k-means for distinguishing various diseases of human brain. Our main aim is to help the doctors by reducing the time complexity in analyzing EEG signal by our detection system which produces better results. We are proposing a technique of detecting epilepsy disorder and Alzheimer disease using k-means algorithm using MATLAB. The back propagation algorithm is also used in the classification network and discrete wavelet transform are used to process the EEG signal. Automated analyses of neurological disorders like Epilepsy, Alzheimer’s disease are being discussed.

  20. Manipulation complexity in primates coevolved with brain size and terrestriality

    OpenAIRE

    Sandra A. Heldstab; Kosonen, Zaida K.; Koski, Sonja E.; Burkart, Judith M.; van Schaik, Carel P.; Karin Isler

    2016-01-01

    Humans occupy by far the most complex foraging niche of all mammals, built around sophisticated technology, and at the same time exhibit unusually large brains. To examine the evolutionary processes underlying these features, we investigated how manipulation complexity is related to brain size, cognitive test performance, terrestriality, and diet quality in a sample of 36 non-human primate species. We categorized manipulation bouts in food-related contexts into unimanual and bimanual actions,...

  1. A Signal-Interleaving Complex Bandpass Sigma-Delta Converter

    DEFF Research Database (Denmark)

    Wad, Paul Emmanuel

    Complex or quadrature Sigma-Delta converters operate on complex signals, i.e. signals consisting of a real and an imaginary component, whereas conventional converters operate only on real signals. The advantage of complex signal processing in the discrete-time domain is that the entire sampling...... frequency bandwidth - not just half of it - is available, and that network zeros and poles can be placed anywhere without having to appear in complex conjugate pairs. This paper demonstrates how these properties can be used to design complex bandpass Sigma-Delta converters with a better noise performance...

  2. Astroglial glutamate transporters coordinate excitatory signaling and brain energetics.

    Science.gov (United States)

    Robinson, Michael B; Jackson, Joshua G

    2016-09-01

    In the mammalian brain, a family of sodium-dependent transporters maintains low extracellular glutamate and shapes excitatory signaling. The bulk of this activity is mediated by the astroglial glutamate transporters GLT-1 and GLAST (also called EAAT2 and EAAT1). In this review, we will discuss evidence that these transporters co-localize with, form physical (co-immunoprecipitable) interactions with, and functionally couple to various 'energy-generating' systems, including the Na(+)/K(+)-ATPase, the Na(+)/Ca(2+) exchanger, glycogen metabolizing enzymes, glycolytic enzymes, and mitochondria/mitochondrial proteins. This functional coupling is bi-directional with many of these systems both being regulated by glutamate transport and providing the 'fuel' to support glutamate uptake. Given the importance of glutamate uptake to maintaining synaptic signaling and preventing excitotoxicity, it should not be surprising that some of these systems appear to 'redundantly' support the energetic costs of glutamate uptake. Although the glutamate-glutamine cycle contributes to recycling of neurotransmitter pools of glutamate, this is an over-simplification. The ramifications of co-compartmentalization of glutamate transporters with mitochondria for glutamate metabolism are discussed. Energy consumption in the brain accounts for ∼20% of the basal metabolic rate and relies almost exclusively on glucose for the production of ATP. However, the brain does not possess substantial reserves of glucose or other fuels. To ensure adequate energetic supply, increases in neuronal activity are matched by increases in cerebral blood flow via a process known as 'neurovascular coupling'. While the mechanisms for this coupling are not completely resolved, it is generally agreed that astrocytes, with processes that extend to synapses and endfeet that surround blood vessels, mediate at least some of the signal that causes vasodilation. Several studies have shown that either genetic deletion or

  3. Complexity of Receptor Tyrosine Kinase Signal Processing

    OpenAIRE

    Volinsky, Natalia; Kholodenko, Boris N.

    2013-01-01

    Our knowledge of molecular mechanisms of receptor tyrosine kinase (RTK) signaling advances with ever-increasing pace. Yet our understanding of how the spatiotemporal dynamics of RTK signaling control specific cellular outcomes has lagged behind. Systems-centered experimental and computational approaches can help reveal how overlapping networks of signal transducers downstream of RTKs orchestrate specific cell-fate decisions. We discuss how RTK network regulatory structures, which involve the ...

  4. Unsupervised classification of operator workload from brain signals

    Science.gov (United States)

    Schultze-Kraft, Matthias; Dähne, Sven; Gugler, Manfred; Curio, Gabriel; Blankertz, Benjamin

    2016-06-01

    Objective. In this study we aimed for the classification of operator workload as it is expected in many real-life workplace environments. We explored brain-signal based workload predictors that differ with respect to the level of label information required for training, including entirely unsupervised approaches. Approach. Subjects executed a task on a touch screen that required continuous effort of visual and motor processing with alternating difficulty. We first employed classical approaches for workload state classification that operate on the sensor space of EEG and compared those to the performance of three state-of-the-art spatial filtering methods: common spatial patterns (CSPs) analysis, which requires binary label information; source power co-modulation (SPoC) analysis, which uses the subjects’ error rate as a target function; and canonical SPoC (cSPoC) analysis, which solely makes use of cross-frequency power correlations induced by different states of workload and thus represents an unsupervised approach. Finally, we investigated the effects of fusing brain signals and peripheral physiological measures (PPMs) and examined the added value for improving classification performance. Main results. Mean classification accuracies of 94%, 92% and 82% were achieved with CSP, SPoC, cSPoC, respectively. These methods outperformed the approaches that did not use spatial filtering and they extracted physiologically plausible components. The performance of the unsupervised cSPoC is significantly increased by augmenting it with PPM features. Significance. Our analyses ensured that the signal sources used for classification were of cortical origin and not contaminated with artifacts. Our findings show that workload states can be successfully differentiated from brain signals, even when less and less information from the experimental paradigm is used, thus paving the way for real-world applications in which label information may be noisy or entirely unavailable.

  5. Processing Motion Signals in Complex Environments

    Science.gov (United States)

    Verghese, Preeti

    2000-01-01

    Motion information is critical for human locomotion and scene segmentation. Currently we have excellent neurophysiological models that are able to predict human detection and discrimination of local signals. Local motion signals are insufficient by themselves to guide human locomotion and to provide information about depth, object boundaries and surface structure. My research is aimed at understanding the mechanisms underlying the combination of motion signals across space and time. A target moving on an extended trajectory amidst noise dots in Brownian motion is much more detectable than the sum of signals generated by independent motion energy units responding to the trajectory segments. This result suggests that facilitation occurs between motion units tuned to similar directions, lying along the trajectory path. We investigated whether the interaction between local motion units along the motion direction is mediated by contrast. One possibility is that contrast-driven signals from motion units early in the trajectory sequence are added to signals in subsequent units. If this were the case, then units later in the sequence would have a larger signal than those earlier in the sequence. To test this possibility, we compared contrast discrimination thresholds for the first and third patches of a triplet of sequentially presented Gabor patches, aligned along the motion direction. According to this simple additive model, contrast increment thresholds for the third patch should be higher than thresholds for the first patch.The lack of a measurable effect on contrast thresholds for these various manipulations suggests that the pooling of signals along a trajectory is not mediated by contrast-driven signals. Instead, these results are consistent with models that propose that the facilitation of trajectory signals is achieved by a second-level network that chooses the strongest local motion signals and combines them if they occur in a spatio-temporal sequence consistent

  6. Emotion Walking for Humanoid Avatars Using Brain Signals

    Directory of Open Access Journals (Sweden)

    Ahmad Hoirul Basori

    2013-01-01

    Full Text Available Interaction between humans and humanoid avatar representations is very important in virtual reality and robotics, since the humanoid avatar can represent either a human or a robot in a virtual environment. Many researchers have focused on providing natural interactions for humanoid avatars or even for robots with the use of camera tracking, gloves, giving them the ability to speak, brain interfaces and other devices. This paper provides a new multimodal interaction control for avatars by combining brain signals, facial muscle tension recognition and glove tracking to change the facial expression of humanoid avatars according to the user’s emotional condition. The signals from brain activity and muscle movements are used as the emotional stimulator, while the glove acts as emotion intensity control for the avatar. This multimodal interface can determine when the humanoid avatar needs to change their facial expression or their walking power. The results show that humanoid avatar have different timelines of walking and facial expressions when the user stimulates them with different emotions. This finding is believed to provide new knowledge on controlling robots’ and humanoid avatars’ facial expressions and walking.

  7. Complexity of Receptor Tyrosine Kinase Signal Processing

    Science.gov (United States)

    Volinsky, Natalia; Kholodenko, Boris N.

    2013-01-01

    Our knowledge of molecular mechanisms of receptor tyrosine kinase (RTK) signaling advances with ever-increasing pace. Yet our understanding of how the spatiotemporal dynamics of RTK signaling control specific cellular outcomes has lagged behind. Systems-centered experimental and computational approaches can help reveal how overlapping networks of signal transducers downstream of RTKs orchestrate specific cell-fate decisions. We discuss how RTK network regulatory structures, which involve the immediate posttranslational and delayed transcriptional controls by multiple feed forward and feedback loops together with pathway cross talk, adapt cells to the combinatorial variety of external cues and conditions. This intricate network circuitry endows cells with emerging capabilities for RTK signal processing and decoding. We illustrate how mathematical modeling facilitates our understanding of RTK network behaviors by unraveling specific systems properties, including bistability, oscillations, excitable responses, and generation of intricate landscapes of signaling activities. PMID:23906711

  8. OPTIMAL REPRESENTATION OF MER SIGNALS APPLIED TO THE IDENTIFICATION OF BRAIN STRUCTURES DURING DEEP BRAIN STIMULATION

    Directory of Open Access Journals (Sweden)

    Hernán Darío Vargas Cardona

    2015-07-01

    Full Text Available Identification of brain signals from microelectrode recordings (MER is a key procedure during deep brain stimulation (DBS applied in Parkinson’s disease patients. The main purpose of this research work is to identify with high accuracy a brain structure called subthalamic nucleus (STN, since it is the target structure where the DBS achieves the best therapeutic results. To do this, we present an approach for optimal representation of MER signals through method of frames. We obtain coefficients that minimize the Euclidean norm of order two. From optimal coefficients, we extract some features from signals combining the wavelet packet and cosine dictionaries. For a comparison frame with the state of the art, we also process the signals using the discrete wavelet transform (DWT with several mother functions. We validate the proposed methodology in a real data base. We employ simple supervised machine learning algorithms, as the K-Nearest Neighbors classifier (K-NN, a linear Bayesian classifier (LDC and a quadratic Bayesian classifier (QDC. Classification results obtained with the proposed method improves significantly the performance of the DWT. We achieve a positive identification of the STN superior to 97,6%. Identification outcomes achieved by the MOF are highly accurate, as we can potentially get a false positive rate of less than 2% during the DBS.

  9. Detection of Brain Tumor in EEG Signals Using Independent Component Analysis

    OpenAIRE

    Rashid, Akram; Tahir, Seema; Choudhury, Aamer Saleem

    2015-01-01

    The Electroencephalogram(EEG) is Scientifically becoming an important tool of measuring brain activity. The EEG data is used to diagnose brain diseases and brain abnormalities. EEG helps to suit the increasing demand of brain tumor detection on affordable prices with better clinical and healthcare services. This research work presents a technique of efficient brain tumor detection in EEG signals using Independent Component Analysis(ICA). EEG signals which actually are carrying information reg...

  10. Manipulation complexity in primates coevolved with brain size and terrestriality.

    Science.gov (United States)

    Heldstab, Sandra A; Kosonen, Zaida K; Koski, Sonja E; Burkart, Judith M; van Schaik, Carel P; Isler, Karin

    2016-01-01

    Humans occupy by far the most complex foraging niche of all mammals, built around sophisticated technology, and at the same time exhibit unusually large brains. To examine the evolutionary processes underlying these features, we investigated how manipulation complexity is related to brain size, cognitive test performance, terrestriality, and diet quality in a sample of 36 non-human primate species. We categorized manipulation bouts in food-related contexts into unimanual and bimanual actions, and asynchronous or synchronous hand and finger use, and established levels of manipulative complexity using Guttman scaling. Manipulation categories followed a cumulative ranking. They were particularly high in species that use cognitively challenging food acquisition techniques, such as extractive foraging and tool use. Manipulation complexity was also consistently positively correlated with brain size and cognitive test performance. Terrestriality had a positive effect on this relationship, but diet quality did not affect it. Unlike a previous study on carnivores, we found that, among primates, brain size and complex manipulations to acquire food underwent correlated evolution, which may have been influenced by terrestriality. Accordingly, our results support the idea of an evolutionary feedback loop between manipulation complexity and cognition in the human lineage, which may have been enhanced by increasingly terrestrial habits. PMID:27075921

  11. Reduced Predictable Information in Brain Signals in Autism Spectrum Disorder

    Directory of Open Access Journals (Sweden)

    Carlos eGomez

    2014-02-01

    Full Text Available Autism spectrum disorder (ASD is a common developmental disorder characterized by communication difficulties and impaired social interaction. Recent results suggest altered brain dynamics as a potential cause of symptoms in ASD. Here, we aim to describe potential information-processing consequences of these alterations by measuring active information storage (AIS – a key quantity in the theory of distributed computation in biological networks. AIS is defined as the mutual information between the semi-infinite past of a process and its next state. It measures the amount of stored information that is used for computation of the next time step of a process. AIS is high for rich but predictable dynamics. We recorded magnetoencephalography (MEG signals in 13 ASD patients and 14 matched control subjects in a visual task. After a beamformer source analysis, twelve task-relevant sources were obtained. For these sources, stationary baseline activity was analyzed using AIS. Our results showed a decrease of AIS values in the hippocampus of ASD patients in comparison with controls, meaning that brain signals in ASD were either less predictable, reduced in their dynamic richness or both. Our study suggests the usefulness of AIS to detect an abnormal type of dynamics in ASD. The observed changes in AIS are compatible with Bayesian theories of reduced use or precision of priors in ASD.

  12. Complex analytic signals applied on time delay estimation

    Directory of Open Access Journals (Sweden)

    Veličković Zoran S.

    2008-01-01

    Full Text Available In this paper, we present the concept of the time delay estimation based on the transformation of real sensor signals into analytic ones. We analyze the differential time delay values obtained using real seismic signals, simulated complex analytic signals and simulated complex analytic signals with real parts coming from real seismic signals. The simulation results indicate that the application of complex analytic signals leads to reliable computation of the differential time delay. The influence of specific signal parameters on spectral coherence threshold in systems for passive localization and proposed methods for lowering the threshold is analyzed. The computation of all differential time delays with respect to the reference sensor (geophone is based on the application of Generalized Cross-Correlation (GCC applied on corresponding analytic signals. The difficulties to select a peak of cross-correlation function that corresponds to true differential time delay when dealing with real signals are significantly reduced if GCC is applied on analytic signals. The efficiency of the proposed technique on differential delay estimation is performed on deterministic and real-life signals.

  13. Complex treatment of malignant glioma of the brain

    International Nuclear Information System (INIS)

    The paper deals with the results of therapy of malignant glioma of the brain using a complex of procedures (surgical removal, nidran chemotherapy and telegammatherapy ) 1991-1997. Therapy and follow-up lasted 2-64 months. Mean survival after treatment was 16 months; 63 % survived more than 24 months; post-operative mortality was 2.4 %

  14. Modulation of EEG Theta Band Signal Complexity by Music Therapy

    Science.gov (United States)

    Bhattacharya, Joydeep; Lee, Eun-Jeong

    The primary goal of this study was to investigate the impact of monochord (MC) sounds, a type of archaic sounds used in music therapy, on the neural complexity of EEG signals obtained from patients undergoing chemotherapy. The secondary goal was to compare the EEG signal complexity values for monochords with those for progressive muscle relaxation (PMR), an alternative therapy for relaxation. Forty cancer patients were randomly allocated to one of the two relaxation groups, MC and PMR, over a period of six months; continuous EEG signals were recorded during the first and last sessions. EEG signals were analyzed by applying signal mode complexity, a measure of complexity of neuronal oscillations. Across sessions, both groups showed a modulation of complexity of beta-2 band (20-29Hz) at midfrontal regions, but only MC group showed a modulation of complexity of theta band (3.5-7.5Hz) at posterior regions. Therefore, the neuronal complexity patterns showed different changes in EEG frequency band specific complexity resulting in two different types of interventions. Moreover, the different neural responses to listening to monochords and PMR were observed after regular relaxation interventions over a short time span.

  15. BrainSignals Revisited: Simplifying a Computational Model of Cerebral Physiology.

    Directory of Open Access Journals (Sweden)

    Matthew Caldwell

    Full Text Available Multimodal monitoring of brain state is important both for the investigation of healthy cerebral physiology and to inform clinical decision making in conditions of injury and disease. Near-infrared spectroscopy is an instrument modality that allows non-invasive measurement of several physiological variables of clinical interest, notably haemoglobin oxygenation and the redox state of the metabolic enzyme cytochrome c oxidase. Interpreting such measurements requires the integration of multiple signals from different sources to try to understand the physiological states giving rise to them. We have previously published several computational models to assist with such interpretation. Like many models in the realm of Systems Biology, these are complex and dependent on many parameters that can be difficult or impossible to measure precisely. Taking one such model, BrainSignals, as a starting point, we have developed several variant models in which specific regions of complexity are substituted with much simpler linear approximations. We demonstrate that model behaviour can be maintained whilst achieving a significant reduction in complexity, provided that the linearity assumptions hold. The simplified models have been tested for applicability with simulated data and experimental data from healthy adults undergoing a hypercapnia challenge, but relevance to different physiological and pathophysiological conditions will require specific testing. In conditions where the simplified models are applicable, their greater efficiency has potential to allow their use at the bedside to help interpret clinical data in near real-time.

  16. Complex signal amplitude analysis for complete fusion nuclear reaction products

    CERN Document Server

    Tsyganov, Yu S

    2015-01-01

    A complex analysis has been performed on the energy amplitude signals corresponding to events of Z=117 element measured in the 249Bk+48Ca complete fusion nuclear reaction. These signals were detected with PIPS position sensitive detector. The significant values of pulse height defect both for recoils (ER) and fission fragments (FF) were measured. Comparison with the computer simulations and empirical formulae has been performed both for ER and FF signals.

  17. Brain Signal Analysis Using Different Types of Music

    Directory of Open Access Journals (Sweden)

    Siti Ayuni Mohd Nasir

    2015-10-01

    Full Text Available Music is able to improve certain functions of human body physiologically and psychologically. Music also can improve attention, memory, and even mental math ability by listening to the music before performing any task. The purpose of this study is to study the relation between types of music and brainwaves signal that is differences in state of relaxation and attention states. The Electroencephalography (EEG signal was recorded using PowerLab, Dual Bio Amp and computer to observes and records the subject brain activity in three condition; before, during, and after listening to different types of music; Light, Rock, Mozart, Al-Quran recitation and Jazz. The brainwave reaction of the subjects is compared during these three conditions. The hypothesis of this study is; Beta wave is increased at attention state and decrease at relaxation state. To analyze the data, Labchart7 software was used. The EEG data that has been recorded is processed using Digital Filter and the features of EEG signal is extracted and recorded by Data Pad that included in Labchart7 software. Then, the data is analyzed from mean of group features and also the average amplitude of Alpha and Beta wave. The results from this study are; the attention state of students is increased (Beta increased while listening to Rock, AlQuran recitation and Mozart music when compared between during and before condition. Meanwhile, Beta wave is decreased while listening to Light and Jazz music thus showing the decrements of student’s state attention. Therefore, the result obtained may help students to choose better type of music or similar to help increases their concentration and focus while study.

  18. Secondary instabilities modulate cortical complexity in the mammalian brain

    Science.gov (United States)

    Budday, Silvia; Steinmann, Paul; Kuhl, Ellen

    2015-10-01

    Disclosing the origin of convolutions in the mammalian brain remains a scientific challenge. Primary folds form before we are born: they are static, well defined and highly preserved across individuals. Secondary folds occur and disappear throughout our entire lifetime: they are dynamic, irregular and highly variable among individuals. While extensive research has improved our understanding of primary folding in the mammalian brain, secondary folding remains understudied and poorly understood. Here, we show that secondary instabilities can explain the increasing complexity of our brain surface as we age. Using the nonlinear field theories of mechanics supplemented by the theory of finite growth, we explore the critical conditions for secondary instabilities. We show that with continuing growth, our brain surface continues to bifurcate into increasingly complex morphologies. Our results suggest that even small geometric variations can have a significant impact on surface morphogenesis. Secondary bifurcations, and with them morphological changes during childhood and adolescence, are closely associated with the formation and loss of neuronal connections. Understanding the correlation between neuronal connectivity, cortical thickness, surface morphology and ultimately behaviour, could have important implications on the diagnostics, classification and treatment of neurological disorders.

  19. Cannabinoid Signaling and Neuroinflammatory Diseases: A Melting pot for the Regulation of Brain Immune Responses.

    Science.gov (United States)

    Chiurchiù, Valerio; Leuti, Alessandro; Maccarrone, Mauro

    2015-06-01

    The concept of the central nervous system (CNS) as an immune-privileged site, essentially due to the presence of the blood brain barrier, appears to be overly simplistic. Indeed, within healthy CNS immune activities are permitted and are required for neuronal function and host defense, not only due to the presence of the resident innate immune cells of the brain, but also by virtue of a complex cross-talk of the CNS with peripheral immune cells. Nonetheless, long-standing and persisting neuroinflammatory responses are most often detrimental and characterize several neuroinflammatory diseases, including multiple sclerosis, Alzheimer's disease and amyotrophic lateral sclerosis. A growing body of evidence suggests that Cannabis sativa-derived phytocannabinoids, as well as synthetic cannabinoids, are endowed with significant immunoregulatory and anti-inflammatory properties, both in peripheral tissues and in the CNS, through the activation of cannabinoid receptors. In this review, the immunomodulatory effects of cannabinoid signaling on the most relevant brain immune cells will be discussed. In addition, the impact of cannabinoid regulation on the overall integration of the manifold brain immune responses will also be highlighted, along with the implication of these compounds as potential agents for the management of neuroinflammatory disorders. PMID:25601726

  20. Systems biology and brain activity in neuronal pathways by smart device and advanced signal processing

    Science.gov (United States)

    Castellani, Gastone; Intrator, Nathan; Remondini, Daniel

    2014-01-01

    Contemporary biomedicine is producing large amount of data, especially within the fields of “omic” sciences. Nevertheless, other fields, such as neuroscience, are producing similar amount of data by using non-invasive techniques such as imaging, functional magnetic resonance and electroencephalography. Nowadays a big challenge and a new research horizon for Systems Biology is to develop methods to integrate and model this data in an unifying framework capable to disentangle this amazing complexity. In this paper we show how methods from genomic data analysis can be applied to brain data. In particular the concept of pathways, networks and multiplex are discussed. These methods can lead to a clear distinction of various regimes of brain activity. Moreover, this method could be the basis for a Systems Biology analysis of brain data and for the integration of these data in a multivariate and multidimensional framework. The feasibility of this integration is strongly dependent from the feature extraction method used. In our case we used an “alphabet” derived from a multi-resolution analysis that is capable to capture the most relevant information from these complex signals. PMID:25206359

  1. Analysis of Spectral Features of EEG signal in Brain Tumor Condition

    Directory of Open Access Journals (Sweden)

    Selvam V. Salai

    2015-08-01

    Full Text Available The scalp electroencephalography (EEG signal is an important clinical tool for the diagnosis of several brain disorders. The objective of the presented work is to analyze the feasibility of the spectral features extracted from the scalp EEG signals in detecting brain tumors. A set of 16 candidate features from frequency domain is considered. The significance on the mean values of these features between 100 brain tumor patients and 102 normal subjects is statistically evaluated. Nine of the candidate features significantly discriminate the brain tumor case from the normal one. The results encourage the use of (quantitative scalp EEG for the diagnosis of brain tumors

  2. Notch-1 Signalling Is Activated in Brain Arteriovenous Malformations in Humans

    Science.gov (United States)

    ZhuGe, Qichuan; Zhong, Ming; Zheng, WeiMing; Yang, Guo-Yuan; Mao, XiaoOu; Xie, Lin; Chen, Gourong; Chen, Yongmei; Lawton, Michael T.; Young, William L.; Greenberg, David A.; Jin, Kunlin

    2009-01-01

    A role for the Notch signalling pathway in the formation of arteriovenous malformations during development has been suggested. However, whether Notch signalling is involved in brain arteriovenous malformations in humans remains unclear. Here, we performed immunohistochemistry on surgically resected brain arteriovenous malformations and found that,…

  3. Causal Mathematical Logic as a guiding framework for the prediction of "Intelligence Signals" in brain simulations

    Science.gov (United States)

    Lanzalaco, Felix; Pissanetzky, Sergio

    2013-12-01

    A recent theory of physical information based on the fundamental principles of causality and thermodynamics has proposed that a large number of observable life and intelligence signals can be described in terms of the Causal Mathematical Logic (CML), which is proposed to encode the natural principles of intelligence across any physical domain and substrate. We attempt to expound the current definition of CML, the "Action functional" as a theory in terms of its ability to possess a superior explanatory power for the current neuroscientific data we use to measure the mammalian brains "intelligence" processes at its most general biophysical level. Brain simulation projects define their success partly in terms of the emergence of "non-explicitly programmed" complex biophysical signals such as self-oscillation and spreading cortical waves. Here we propose to extend the causal theory to predict and guide the understanding of these more complex emergent "intelligence Signals". To achieve this we review whether causal logic is consistent with, can explain and predict the function of complete perceptual processes associated with intelligence. Primarily those are defined as the range of Event Related Potentials (ERP) which include their primary subcomponents; Event Related Desynchronization (ERD) and Event Related Synchronization (ERS). This approach is aiming for a universal and predictive logic for neurosimulation and AGi. The result of this investigation has produced a general "Information Engine" model from translation of the ERD and ERS. The CML algorithm run in terms of action cost predicts ERP signal contents and is consistent with the fundamental laws of thermodynamics. A working substrate independent natural information logic would be a major asset. An information theory consistent with fundamental physics can be an AGi. It can also operate within genetic information space and provides a roadmap to understand the live biophysical operation of the phenotype

  4. Analysis of Spectral Features of EEG signal in Brain Tumor Condition

    OpenAIRE

    Selvam V. Salai; Devi S. Shenbaga

    2015-01-01

    The scalp electroencephalography (EEG) signal is an important clinical tool for the diagnosis of several brain disorders. The objective of the presented work is to analyze the feasibility of the spectral features extracted from the scalp EEG signals in detecting brain tumors. A set of 16 candidate features from frequency domain is considered. The significance on the mean values of these features between 100 brain tumor patients and 102 normal subjects is statistically evaluated. Nine of the c...

  5. Amplified Signal Response by Neuronal Diversity on Complex Networks

    International Nuclear Information System (INIS)

    The effect of diversity on dynamics of coupled FitzHugh–Nagumo neurons on complex networks is numerically investigated, where each neuron is subjected to an external subthreshold signal. With the diversity the network is a mixture of excitable and oscillatory neurons, and the diversity is determined by the variance of the system's parameter. The complex network is constructed by randomly adding long-range connections (shortcuts) on a nearest-neighbouring coupled one-dimensional chain. Numerical results show that external signals are maximally magnified at an intermediate value of the diversity, as in the case of well-known stochastic resonance. Furthermore, the effects of the number of shortcuts and coupled strength on the diversity-induced phenomena are also discussed. These findings exhibit that the diversity may play a constructive role in response to external signal, and highlight the importance of the diversity on such complex networks. (general)

  6. Altered Structural Brain Networks in Tuberous Sclerosis Complex.

    Science.gov (United States)

    Im, Kiho; Ahtam, Banu; Haehn, Daniel; Peters, Jurriaan M; Warfield, Simon K; Sahin, Mustafa; Ellen Grant, P

    2016-05-01

    Tuberous sclerosis complex (TSC) is characterized by benign hamartomas in multiple organs including the brain and its clinical phenotypes may be associated with abnormal neural connections. We aimed to provide the first detailed findings on disrupted structural brain networks in TSC patients. Structural whole-brain connectivity maps were constructed using structural and diffusion MRI in 20 TSC (age range: 3-24 years) and 20 typically developing (TD; 3-23 years) subjects. We assessed global (short- and long-association and interhemispheric fibers) and regional white matter connectivity, and performed graph theoretical analysis using gyral pattern- and atlas-based node parcellations. Significantly higher mean diffusivity (MD) was shown in TSC patients than in TD controls throughout the whole brain and positively correlated with tuber load severity. A significant increase in MD was mainly influenced by an increase in radial diffusivity. Furthermore, interhemispheric connectivity was particularly reduced in TSC, which leads to increased network segregation within hemispheres. TSC patients with developmental delay (DD) showed significantly higher MD than those without DD primarily in intrahemispheric connections. Our analysis allows non-biased determination of differential white matter involvement, which may provide better measures of "lesion load" and lead to a better understanding of disease mechanisms. PMID:25750257

  7. Complex-wave retrieval based on blind signal separation

    Institute of Scientific and Technical Information of China (English)

    Xiaodong Chai; Chengpeng Zhou; Zhaoyan Feng; Yinhua Wang; Yansheng Zuo

    2006-01-01

    In the process of the reconstruction of digital holography, the traditional methods of diffraction and filtration are commonly adopted to recover the original complex-wave signal. Influenced by twin-image and zero-order terms, the above-mentioned methods, however, either limit the field of vision or result in the loss of the amplitude and phase. A new method for complex-wave retrieval is presented, which is based on blind signal separation. Three frames of holograms are captured by a charge coupled device (CCD)camera to form an observation signal. The term containing only amplitude and phase of complex-wave is separated, by means of independent component analysis, from the observation signal, which effectively eliminates the zero-order term. Finally, the complex-wave retrieval of pure phase wavefront is achieved.Experimental results show that this method can better recover the amplitude and phase of the original complex-wave even when there is a frequency spectrum mixture in the hologram.

  8. Brain responses in humans reveal ideal observer-like sensitivity to complex acoustic patterns.

    Science.gov (United States)

    Barascud, Nicolas; Pearce, Marcus T; Griffiths, Timothy D; Friston, Karl J; Chait, Maria

    2016-02-01

    We use behavioral methods, magnetoencephalography, and functional MRI to investigate how human listeners discover temporal patterns and statistical regularities in complex sound sequences. Sensitivity to patterns is fundamental to sensory processing, in particular in the auditory system, because most auditory signals only have meaning as successions over time. Previous evidence suggests that the brain is tuned to the statistics of sensory stimulation. However, the process through which this arises has been elusive. We demonstrate that listeners are remarkably sensitive to the emergence of complex patterns within rapidly evolving sound sequences, performing on par with an ideal observer model. Brain responses reveal online processes of evidence accumulation--dynamic changes in tonic activity precisely correlate with the expected precision or predictability of ongoing auditory input--both in terms of deterministic (first-order) structure and the entropy of random sequences. Source analysis demonstrates an interaction between primary auditory cortex, hippocampus, and inferior frontal gyrus in the process of discovering the regularity within the ongoing sound sequence. The results are consistent with precision based predictive coding accounts of perceptual inference and provide compelling neurophysiological evidence of the brain's capacity to encode high-order temporal structure in sensory signals. PMID:26787854

  9. Lectures in Supercomputational Neurosciences Dynamics in Complex Brain Networks

    CERN Document Server

    Graben, Peter beim; Thiel, Marco; Kurths, Jürgen

    2008-01-01

    Computational Neuroscience is a burgeoning field of research where only the combined effort of neuroscientists, biologists, psychologists, physicists, mathematicians, computer scientists, engineers and other specialists, e.g. from linguistics and medicine, seem to be able to expand the limits of our knowledge. The present volume is an introduction, largely from the physicists' perspective, to the subject matter with in-depth contributions by system neuroscientists. A conceptual model for complex networks of neurons is introduced that incorporates many important features of the real brain, such as various types of neurons, various brain areas, inhibitory and excitatory coupling and the plasticity of the network. The computational implementation on supercomputers, which is introduced and discussed in detail in this book, will enable the readers to modify and adapt the algortihm for their own research. Worked-out examples of applications are presented for networks of Morris-Lecar neurons to model the cortical co...

  10. Aliasing in the Complex Cepstrum of Linear-Phase Signals

    DEFF Research Database (Denmark)

    Bysted, Tommy Kristensen

    1997-01-01

    Assuming linear-phase of the associated time signal, this paper presents an approximated analytical description of the unavoidable aliasing in practical use of complex cepstrums. The linear-phase assumption covers two major applications of complex cepstrums which are linear- to minimum-phase FIR......-filter transformation and minimum-phase estimation from amplitude specifications. The description is made in the cepstrum domain, the Fourier transform of the complex cepstrum and in the frequency domain. Two examples are given, one for verification of the derived equations and one using the description to reduce...

  11. Model of the Brain Tumor–Pumilio translation repressor complex

    OpenAIRE

    Edwards, Thomas A.; Wilkinson, Brian D.; Wharton, Robin P.; Aggarwal, Aneel K.

    2003-01-01

    The Brain Tumor (Brat) protein is recruited to the 3′ untranslated region (UTR) of hunchback mRNA to regulate its translation. Recruitment is mediated by interactions between the Pumilio RNA-binding Puf repeats and the NHL domain of Brat, a conserved structural motif present in a large family of growth regulators. In this report, we describe the crystal structure of the Brat NHL domain and present a model of the Pumilio–Brat complex derived from in silico docking experiments and supported by ...

  12. Denoising and Frequency Analysis of Noninvasive Magnetoencephalography Sensor Signals for Functional Brain Mapping

    CERN Document Server

    Ukil, A

    2015-01-01

    Magnetoencephalography (MEG) is an important noninvasive, nonhazardous technology for functional brain mapping, measuring the magnetic fields due to the intracellular neuronal current flow in the brain. However, most often, the inherent level of noise in the MEG sensor data collection process is large enough to obscure the signal(s) of interest. In this paper, a denoising technique based on the wavelet transform and the multiresolution signal decomposition technique along with thresholding is presented, substantiated by application results. Thereafter, different frequency analysis are performed on the denoised MEG signals to identify the major frequencies of the brain oscillations present in the denoised signals. Time-frequency plots (spectrograms) of the denoised signals are also provided.

  13. Levels of complexity in scale-invariant neural signals

    Science.gov (United States)

    Ivanov, Plamen Ch.; Ma, Qianli D. Y.; Bartsch, Ronny P.

    2012-02-01

    Many physiological systems exhibit complex scale-invariant and nonlinear features characterized long-range power-law correlations, indicating a possibly common control mechanism. It has been suggested that dynamical processes, influenced by inputs and feedback on multiple time scales, may be sufficient to give rise to this complexity. Two examples of physiologic signals that are the output of hierarchical multiscale physiologic systems under neural control are the human heartbeat and human gait. We show that while both cardiac interbeat interval and gait interstride interval time series under healthy conditions have comparable scale-invariant behavior, they still belong to different complexity classes. We compare results from empirical findings and stochastic feedback modeling approaches to cardiac and locomotor dynamics, which provide new insights into the multicomponent neural mechanisms regulating these complex systems.

  14. Age-dependent complex noise fluctuations in the brain

    International Nuclear Information System (INIS)

    We investigated the parameters of colored noise in EEG data of 17 722 professional drivers aged 18–70. The whole study is based upon experiments showing that biological neural networks may operate in the vicinity of the critical point and that the balance between excitation and inhibition in the human brain is important for the transfer of information. This paper is devoted to the study of EEG power spectrum which can be described best by a power function with 1/fλ distribution and colored noise corresponding to the critical point in the EEG signal has the value of λ = 1 (purple noise). The slow accumulation of energy and its quick release is a universal property of the 1/f distribution. The physiological mechanism causing energy dissipation in the brain seems to depend on the number and strength of the connections between clusters of neurons. With ageing, the number of connections between the neurons decreases. Learning ability and intellectual performance also decrease. Therefore, age-related changes in the λ coefficient can be anticipated. We found that absolute values of λ coefficients decrease significantly with increasing age. Deviations from this rule are related to age-dependent slowing of the dominant frequency in the alpha band. Age-dependent change in the parameter and colored noise may be indicative of age-related changes in the self-organization of brain activity. Results obtained include (i) the age-dependent decrease of the absolute values of the average λ coefficient with the regression coefficient 0.005 1/year, (ii) distribution of λ value changes related to EEG frequency bands and to localization of electrodes on the scalp, and (iii) relation of age-dependent changes of colored noise and EEG energy in separate frequency bands. (paper)

  15. Antagonism of purinergic signalling improves recovery from traumatic brain injury

    OpenAIRE

    Choo, Anthony M.; William J. Miller; Chen, Yung-Chia; Nibley, Philip; Patel, Tapan P.; Goletiani, Cezar; Morrison, Barclay; Kutzing, Melinda K.; Firestein, Bonnie L.; Sul, Jai-Yoon; Haydon, Philip G.; Meaney, David F.

    2013-01-01

    The recent public awareness of the incidence and possible long-term consequences of traumatic brain injury only heightens the need to develop effective approaches for treating this neurological disease. In this report, we identify a new therapeutic target for traumatic brain injury by studying the role of astrocytes, rather than neurons, after neurotrauma. We use in vivo multiphoton imaging and show that mechanical forces during trauma trigger intercellular calcium waves throughout the astroc...

  16. A Novel Approach for Detecting QRS Complex of ECG signal

    Directory of Open Access Journals (Sweden)

    Sameer K Salih

    2012-11-01

    Full Text Available In this study, an automatic approach for detecting QRS complexes and evaluating related R-R intervals of ECG signals (PNDM is proposed. It reliably recognizes QRS complexes based on the deflection occurred between R S waves as a large positive and negative interval with respect to other ECG signal waves. The proposed detection method follows new fast direct algorithm applied to the entire ECG record itself without additional transformation like discrete wavelet transform (DWT or any filtering sequence. Mostly used records in the online ECG database (MIT-BIH Arrhythmia have been used to evaluate the new technique. Moreover it was compared to seven existing techniques; the results show that PNDM has much detection performances according to 99.95% sensitivity and 99.97% specificity. It is also quickest than comparable methods.

  17. Assembly of Oligomeric Death Domain Complexes during Toll Receptor Signaling*

    OpenAIRE

    Moncrieffe, Martin C.; Grossmann, J. Günter; Gay, Nicholas J.

    2008-01-01

    The Drosophila Toll receptor is activated by the endogenous protein ligand Spätzle in response to microbial stimuli in immunity and spatial cues during embryonic development. Downstream signaling is mediated by the adaptor proteins Tube, the kinase Pelle, and the Drosophila homologue of myeloid differentiation primary response protein (dMyD88). Here we have characterized heterodimeric (dMyD88-Tube) and heterotrimeric (dMyD88-Tube-Pelle) death domain complexes. We show ...

  18. Caveolins: Targeting Pro-survival Signaling in the Heart and Brain

    Directory of Open Access Journals (Sweden)

    CreedM.Stary

    2012-10-01

    Full Text Available The present review discusses intracellular signaling moieties specific to membrane lipid rafts (MLRs and the scaffolding proteins caveolin and introduces current data promoting their potential role in the treatment of pathologies of the heart and brain. MLRs are discreet microdomains of the plasma membrane enriched in gylcosphingolipids and cholesterol that concentrate and localize signaling molecules. Caveolin proteins are necessary for the formation of MLRs, and are responsible for coordinating signaling events by scaffolding and enriching numerous signaling moieties in close proximity. Specifically in the heart and brain, caveolins are necessary for the cytoprotective phenomenon termed ischemic and anesthetic preconditioning. Targeted overexpression of caveolin in the heart and brain leads to induction of multiple pro-survival and pro-growth signaling pathways; thus, caveolins represent a potential novel therapeutic target for cardaic and neurological pathologies.

  19. The Nonrandom Brain: Efficiency, Economy, and Complex Dynamics

    Directory of Open Access Journals (Sweden)

    Olaf Sporns

    2011-02-01

    Full Text Available Modern anatomical tracing and imaging techniques are beginning to reveal the structural anatomy of neural circuits at small and large scales in unprecedented detail. When examined with analytic tools from graph theory and network science, neural connectivity exhibits highly nonrandom features, including high clustering and short path length, as well as modules and highly central hub nodes. These characteristic topological features of neural connections shape nonrandom dynamic interactions that occur during spontaneous activity or in response to external stimulation. Disturbances of connectivity and thus of neural dynamics are thought to underlie a number of disease states of the brain, and some evidence suggests that degraded functional performance of brain networks may be the outcome of a process of randomization affecting their nodes and edges. This article provides a survey of the nonrandom structure of neural connectivity, primarily at the large-scale of regions and pathways in the mammalian cerebral cortex. In addition, we will discuss how nonrandom connections can give rise to differentiated and complex patterns of dynamics and information flow. Finally, we will explore the idea that at least some disorders of the nervous system are associated with increased randomness of neural connections.

  20. Convergent evolution of complex brains and high intelligence.

    Science.gov (United States)

    Roth, Gerhard

    2015-12-19

    Within the animal kingdom, complex brains and high intelligence have evolved several to many times independently, e.g. among ecdysozoans in some groups of insects (e.g. blattoid, dipteran, hymenopteran taxa), among lophotrochozoans in octopodid molluscs, among vertebrates in teleosts (e.g. cichlids), corvid and psittacid birds, and cetaceans, elephants and primates. High levels of intelligence are invariantly bound to multimodal centres such as the mushroom bodies in insects, the vertical lobe in octopodids, the pallium in birds and the cerebral cortex in primates, all of which contain highly ordered associative neuronal networks. The driving forces for high intelligence may vary among the mentioned taxa, e.g. needs for spatial learning and foraging strategies in insects and cephalopods, for social learning in cichlids, instrumental learning and spatial orientation in birds and social as well as instrumental learning in primates. PMID:26554042

  1. Prompt recognition of brain states by their EEG signals

    DEFF Research Database (Denmark)

    Peters, B.O.; Pfurtscheller, G.; Flyvbjerg, H.

    1997-01-01

    Brain states corresponding to intention of movement of left and right index finger and right foot are classified by a ''committee'' of artificial neural networks processing individual channels of 56-electrode electroencephalograms (EEGs). Correct recognition is achieved in 83% of cases not previo......Brain states corresponding to intention of movement of left and right index finger and right foot are classified by a ''committee'' of artificial neural networks processing individual channels of 56-electrode electroencephalograms (EEGs). Correct recognition is achieved in 83% of cases...... not previously seen by the system on the basis of 1 sec long EEGs....

  2. Brain-computer interfaces: an overview of the hardware to record neural signals from the cortex.

    Science.gov (United States)

    Stieglitz, Thomas; Rubehn, Birthe; Henle, Christian; Kisban, Sebastian; Herwik, Stanislav; Ruther, Patrick; Schuettler, Martin

    2009-01-01

    Brain-computer interfaces (BCIs) record neural signals from cortical origin with the objective to control a user interface for communication purposes, a robotic artifact or artificial limb as actuator. One of the key components of such a neuroprosthetic system is the neuro-technical interface itself, the electrode array. In this chapter, different designs and manufacturing techniques will be compared and assessed with respect to scaling and assembling limitations. The overview includes electroencephalogram (EEG) electrodes and epicortical brain-machine interfaces to record local field potentials (LFPs) from the surface of the cortex as well as intracortical needle electrodes that are intended to record single-unit activity. Two exemplary complementary technologies for micromachining of polyimide-based arrays and laser manufacturing of silicone rubber are presented and discussed with respect to spatial resolution, scaling limitations, and system properties. Advanced silicon micromachining technologies have led to highly sophisticated intracortical electrode arrays for fundamental neuroscientific applications. In this chapter, major approaches from the USA and Europe will be introduced and compared concerning complexity, modularity, and reliability. An assessment of the different technological solutions comparable to a strength weaknesses opportunities, and threats (SWOT) analysis might serve as guidance to select the adequate electrode array configuration for each control paradigm and strategy to realize robust, fast, and reliable BCIs. PMID:19660664

  3. Aging. Aging-induced type I interferon signaling at the choroid plexus negatively affects brain function

    Science.gov (United States)

    Baruch, Kuti; Deczkowska, Aleksandra; David, Eyal; Castellano, Joseph M.; Miller, Omer; Kertser, Alexander; Berkutzki, Tamara; Barnett-Itzhaki, Zohar; Bezalel, Dana; Wyss-Coray, Tony; Amit, Ido; Schwartz, Michal

    2016-01-01

    Age-associated cognitive decline is affected by factors produced inside and outside the brain. We found in aged mice and humans, that the choroid plexus (CP), an epithelial interface between the brain and the circulation, shows a type I interferon (IFN-I)-dependent expression profile, often associated with anti-viral responses. This signature was induced by brain-derived signals present in the cerebrospinal fluid of aged mice. Blocking IFN-I signaling within the brain of cognitively-impaired aged mice, using IFN-I receptor neutralizing antibody, led to partial restoration of cognitive function and hippocampal neurogenesis, and reestablished IFN-II-dependent CP activity, lost in aging. Our data identify an aging-induced IFN-I signature at the CP, and demonstrate its negative influence on brain function, thereby suggesting a potential target for therapeutic intervention for age-related cognitive decline. PMID:25147279

  4. The statistical mechanics of complex signaling networks: nerve growth factor signaling

    Science.gov (United States)

    Brown, K. S.; Hill, C. C.; Calero, G. A.; Myers, C. R.; Lee, K. H.; Sethna, J. P.; Cerione, R. A.

    2004-10-01

    The inherent complexity of cellular signaling networks and their importance to a wide range of cellular functions necessitates the development of modeling methods that can be applied toward making predictions and highlighting the appropriate experiments to test our understanding of how these systems are designed and function. We use methods of statistical mechanics to extract useful predictions for complex cellular signaling networks. A key difficulty with signaling models is that, while significant effort is being made to experimentally measure the rate constants for individual steps in these networks, many of the parameters required to describe their behavior remain unknown or at best represent estimates. To establish the usefulness of our approach, we have applied our methods toward modeling the nerve growth factor (NGF)-induced differentiation of neuronal cells. In particular, we study the actions of NGF and mitogenic epidermal growth factor (EGF) in rat pheochromocytoma (PC12) cells. Through a network of intermediate signaling proteins, each of these growth factors stimulates extracellular regulated kinase (Erk) phosphorylation with distinct dynamical profiles. Using our modeling approach, we are able to predict the influence of specific signaling modules in determining the integrated cellular response to the two growth factors. Our methods also raise some interesting insights into the design and possible evolution of cellular systems, highlighting an inherent property of these systems that we call 'sloppiness.'

  5. EGFR Signaling in the Brain Is Necessary for Olfactory Learning in "Drosophila" Larvae

    Science.gov (United States)

    Rahn, Tasja; Leippe, Matthias; Roeder, Thomas; Fedders, Henning

    2013-01-01

    Signaling via the epidermal growth factor receptor (EGFR) pathway has emerged as one of the key mechanisms in the development of the central nervous system in "Drosophila melanogaster." By contrast, little is known about the functions of EGFR signaling in the differentiated larval brain. Here, promoter-reporter lines of EGFR and its most prominent…

  6. Prompt recognition of brain states by their EEG signals

    DEFF Research Database (Denmark)

    Peters, B.O.; Pfurtscheller, G.; Flyvbjerg, H.

    1997-01-01

    Brain states corresponding to intention of movement of left and right index finger and right foot are classified by a ''committee'' of artificial neural networks processing individual channels of 56-electrode electroencephalograms (EEGs). Correct recognition is achieved in 83% of cases not previo...

  7. Signaling the Unfolded Protein Response in primary brain cancers.

    Science.gov (United States)

    Le Reste, Pierre-Jean; Avril, Tony; Quillien, Véronique; Morandi, Xavier; Chevet, Eric

    2016-07-01

    The Unfolded Protein Response (UPR) is an adaptive cellular program used by eukaryotic cells to cope with protein misfolding stress in the Endoplasmic Reticulum (ER). During tumor development, cancer cells are facing intrinsic (oncogene activation) and extrinsic (limiting nutrient or oxygen supply; exposure to chemotherapies) challenges, with which they must cope to survive. Primary brain tumors are relatively rare but deadly and present a significant challenge in the determination of risk factors in the population. These tumors are inherently difficult to cure because of their protected location in the brain. As such surgery, radiation and chemotherapy options carry potentially lasting patient morbidity and incomplete tumor cure. Some of these tumors, such as glioblastoma, were reported to present features of ER stress and to depend on UPR activation to sustain growth, but to date there is no clear general representation of the ER stress status in primary brain tumors. In this review, we describe the key molecular mechanisms controlling the UPR and their implication in cancers. Then we extensively review the literature reporting the status of ER stress in various primary brain tumors and discuss the potential impact of such observation on patient stratification and on the possibility of developing appropriate targeted therapies using the UPR as therapeutic target. PMID:27016056

  8. The alterations in biochemical signaling of hippocampal network activity in the autism brain The alterations in biochemical signaling of hippocampal network activity in the autism brain The alterations in biochemical signaling of hippocampal network activity in the autism brain

    Institute of Scientific and Technical Information of China (English)

    田允; 黄继云; 王锐; 陶蓉蓉; 卢应梅; 廖美华; 陆楠楠; 李静; 芦博; 韩峰

    2012-01-01

    Autism is a highly heritable neurodevelopmental condition characterized by impaired social interaction and communication. However, the role of synaptic dysfunction during development of autism remains unclear. In the present study, we address the alterations of biochemical signaling in hippocampal network following induction of the autism in experimental animals. Here, the an- imal disease model and DNA array being used to investigate the differences in transcriptome or- ganization between autistic and normal brain by gene co--expression network analysis.

  9. Multilevel complexity of calcium signaling:Modeling angiogenesis

    Institute of Scientific and Technical Information of China (English)

    Luca; Munaron; Marco; Scianna

    2012-01-01

    Intracellular calcium signaling is a universal,evolutionary conserved and versatile regulator of cell biochemistry.The complexity of calcium signaling and related cell machinery can be investigated by the use of experimental strategies,as well as by computational approaches.Vascular endothelium is a fascinating model to study the specific properties and roles of calcium signals at multiple biological levels.During the past 20 years,live cell imaging,patch clamp and other techniques have allowed us to detect and interfere with calcium signaling in endothelial cells(ECs),providing a huge amount of information on the regulation of vascularization(angiogenesis) in normal and tumoral tissues.These data range from the spatiotemporal dynamics of calcium within different cell microcompartments to those in entire multicellular and organized EC networks.Beside experimental strategies,in silico endothelial models,specifically designed for simulating calcium signaling,are contributing to our knowledge of vascular physiol-ogy and pathology.They help to investigate and predict the quantitative features of proangiogenic events moving through subcellular,cellular and supracellular levels.This review focuses on some recent developments of computational approaches for proangiogenic endothelial calcium signaling.In particular,we discuss the creation of hybrid simulation environments,which combine and integrate discrete Cellular Potts Models.They are able to capture the phenomenological mechanisms of cell morphological reorganization,migration,and intercellular adhesion,with single-cell spatiotemporal models,based on reaction-diffusion equations that describe the agonist-induced intracellular calcium events.

  10. Complex courtship displays facilitate male reproductive success and plasticity in signaling across variable environments

    OpenAIRE

    Dustin J. WILGERS, Eileen A. HEBETS

    2011-01-01

    Effective signal transmission is essential for communication. In environments where signal transmission is highly variable, signalers may utilize complex signals, which incorporate multiple components and modalities, to maintain effective communication. Male Rabidosa rabida wolf spiders produce complex courtship signals, consisting of both visual and seismic components. We test the hypothesis that the complex signaling of R. rabida contributes to male reproductive success in variable signalin...

  11. Human-machine interface based on muscular and brain signals applied to a robotic wheelchair

    International Nuclear Information System (INIS)

    This paper presents a Human-Machine Interface (HMI) based on the signals generated by eye blinks or brain activity. The system structure and the signal acquisition and processing are shown. The signals used in this work are either the signal associated to the muscular movement corresponding to an eye blink or the brain signal corresponding to visual information processing. The variance is the feature extracted from such signals in order to detect the intention of the user. The classification is performed by a variance threshold which is experimentally determined for each user during the training stage. The command options, which are going to be sent to the commanded device, are presented to the user in the screen of a PDA (Personal Digital Assistant). In the experiments here reported, a robotic wheelchair is used as the device being commanded

  12. Adaptive and aberrant reward prediction signals in the human brain.

    NARCIS (Netherlands)

    Roiser, J.P.; Stephan, K.E.; Ouden, H.E.M. den; Friston, K.J.; Joyce, E.M.

    2010-01-01

    Theories of the positive symptoms of schizophrenia hypothesize a role for aberrant reinforcement signaling driven by dysregulated dopamine transmission. Recently, we provided evidence of aberrant reward learning in symptomatic, but not asymptomatic patients with schizophrenia, using a novel paradigm

  13. Brain Signal Analysis Using Different Types of Music

    OpenAIRE

    Siti Ayuni Mohd Nasir; Wan Mahani Hafizah Wan Mahmud

    2015-01-01

    Music is able to improve certain functions of human body physiologically and psychologically. Music also can improve attention, memory, and even mental math ability by listening to the music before performing any task. The purpose of this study is to study the relation between types of music and brainwaves signal that is differences in state of relaxation and attention states. The Electroencephalography (EEG) signal was recorded using PowerLab, Dual Bio Amp and computer to observes and record...

  14. Kappa-opioid receptor signaling and brain reward function

    OpenAIRE

    Bruijnzeel, Adrie W.

    2009-01-01

    The dynorphin-like peptides have profound effects on the state of the brain reward system and human and animal behavior. The dynorphin-like peptides affect locomotor activity, food intake, sexual behavior, anxiety-like behavior, and drug intake. Stimulation of kappa-opioid receptors, the endogenous receptor for the dynorphin-like peptides, inhibits dopamine release in the striatum (nucleus accumbens and caudate putamen) and induces a negative mood state in humans and animals. The administrati...

  15. Emotion Walking for Humanoid Avatars Using Brain Signals

    OpenAIRE

    Ahmad Hoirul Basori

    2013-01-01

    Interaction between humans and humanoid avatar representations is very important in virtual reality and robotics, since the humanoid avatar can represent either a human or a robot in a virtual environment. Many researchers have focused on providing natural interactions for humanoid avatars or even for robots with the use of camera tracking, gloves, giving them the ability to speak, brain interfaces and other devices. This paper provides a new multimodal interaction control for avatars by comb...

  16. Complex Interplay of Hormonal Signals during Grape Berry Ripening

    Directory of Open Access Journals (Sweden)

    Ana Margarida Fortes

    2015-05-01

    Full Text Available Grape and wine production and quality is extremely dependent on the fruit ripening process. Sensory and nutritional characteristics are important aspects for consumers and their development during fruit ripening involves complex hormonal control. In this review, we explored data already published on grape ripening and compared it with the hormonal regulation of ripening of other climacteric and non-climacteric fruits. The roles of abscisic acid, ethylene, and brassinosteroids as promoters of ripening are discussed, as well as the role of auxins, cytokinins, gibberellins, jasmonates, and polyamines as inhibitors of ripening. In particular, the recently described role of polyamine catabolism in grape ripening is discussed, together with its putative interaction with other hormones. Furthermore, other recent examples of cross-talk among the different hormones are presented, revealing a complex interplay of signals during grape development and ripening.

  17. The Complex Functioning of the Human Brain: The Two Hemispheres

    OpenAIRE

    Iulia Cristina Timofti

    2010-01-01

    The present study reveals just a glimpse of the possible functions and reactions that the human brain can have. I considered as good examples different situations characteristic both of a normal person and a split-brain one. These situations prove that the brain, although divided in two, works as a unit, as an amazing computer that has data processing as a main goal.

  18. A signaling network for patterning of neuronal connectivity in the Drosophila brain.

    Directory of Open Access Journals (Sweden)

    Mohammed Srahna

    2006-10-01

    Full Text Available The precise number and pattern of axonal connections generated during brain development regulates animal behavior. Therefore, understanding how developmental signals interact to regulate axonal extension and retraction to achieve precise neuronal connectivity is a fundamental goal of neurobiology. We investigated this question in the developing adult brain of Drosophila and find that it is regulated by crosstalk between Wnt, fibroblast growth factor (FGF receptor, and Jun N-terminal kinase (JNK signaling, but independent of neuronal activity. The Rac1 GTPase integrates a Wnt-Frizzled-Disheveled axon-stabilizing signal and a Branchless (FGF-Breathless (FGF receptor axon-retracting signal to modulate JNK activity. JNK activity is necessary and sufficient for axon extension, whereas the antagonistic Wnt and FGF signals act to balance the extension and retraction required for the generation of the precise wiring pattern.

  19. Transmembrane signaling through major histocompatibility complex (MHC) encoded molecules

    International Nuclear Information System (INIS)

    The importance of the major histocompatibility complex (MHC) encoded molecules has traditionally been ascribed to the role these molecules play as restriction elements for T lymphocytes. This is, in order for T cell activation to occur the T cell must recognize antigen in association with MHC molecules. More controversial, however, is the potential role MHC molecules play as signal transducing receptors/acceptors to the B lymphocyte. In other words, do class II MHC molecules (Ia antigens) actively transduce a signal to the B cell which drives its differentiation into an antibody secreting cell? Two approaches to this question are described. The first involves biochemical characterization of those molecules which consistently copurify with I-A/sup k/ by two dimensional gel electrophoresis. The second approach utilizes two types of analyses: first, an examination of the biochemical changes which occur in the cell as a result of Ia ligation; and second, analysis of changes in the B cell's physiological response as a result of Ia perturbation. Molecules were examined which may couple the antigen binding event in the B lymphocyte to the antigen driven signal transduction cascade which ultimately leads to immunoglobulin secretion. In these experiments, cells were labelled with [32P] and stimulated cells with phorbol myristate acetate. The membrane form of immunoglobulin was then isolated from detergent lysates of whole cells and passed over an anti-k affinity column. The eluates were analyzed by SDS-PAGE

  20. ALFY-Controlled DVL3 Autophagy Regulates Wnt Signaling, Determining Human Brain Size.

    Directory of Open Access Journals (Sweden)

    Rotem Kadir

    2016-03-01

    Full Text Available Primary microcephaly is a congenital neurodevelopmental disorder of reduced head circumference and brain volume, with fewer neurons in the cortex of the developing brain due to premature transition between symmetrical and asymmetrical cellular division of the neuronal stem cell layer during neurogenesis. We now show through linkage analysis and whole exome sequencing, that a dominant mutation in ALFY, encoding an autophagy scaffold protein, causes human primary microcephaly. We demonstrate the dominant effect of the mutation in drosophila: transgenic flies harboring the human mutant allele display small brain volume, recapitulating the disease phenotype. Moreover, eye-specific expression of human mutant ALFY causes rough eye phenotype. In molecular terms, we demonstrate that normally ALFY attenuates the canonical Wnt signaling pathway via autophagy-dependent removal specifically of aggregates of DVL3 and not of Dvl1 or Dvl2. Thus, autophagic attenuation of Wnt signaling through removal of Dvl3 aggregates by ALFY acts in determining human brain size.

  1. The evolution of complex brains and behaviors in African cichlid fishes

    Directory of Open Access Journals (Sweden)

    Caroly A. Shumway

    2010-02-01

    Full Text Available In this review, I explore the effects of both social organization and the physical environment, specifically habitat complexity, on the brains and behavior of highly visual African cichlid fishes, drawing on examples from primates and birds where appropriate. In closely related fishes from the monophyletic Ectodinii clade of Lake Tanganyika, both forces influence cichlid brains and behavior. Considering social influences first, visual acuity differs with respect to social organization (monogamy versus polygyny. Both the telencephalon and amygdalar homologue, area Dm, are larger in monogamous species. Monogamous species are found to have more vasotocin-immunoreactive cells in the preoptic area of the brain. Habitat complexity also influences brain and behavior in these fishes. Total brain size, telencephalic and cerebellar size are positively correlated with habitat complexity. Visual acuity and spatial memory are enhanced in cichlids living in more complex environments. However habitat complexity and social forces affect cichlid brains differently. Taken together, our field data and plasticity data suggest that some of the species-specific neural effects of habitat complexity could be the consequence of the corresponding social correlates. Environmental forces, however, exert a broader effect on brain structures than social ones do, suggesting allometric expansion of the brain structures in concert with brain size and/or co-evolution of these structures [Current Zoology 56 (1: 144–156 2010].

  2. Eph Receptor and Ephrin Signaling in Developing and Adult Brain of the Honeybee (Apis mellifera)

    OpenAIRE

    Vidovic, Maria; Nighorn, Alan; Koblar, Simon; Maleszka, Ryszard

    2007-01-01

    Roles for Eph receptor tyrosine kinase and ephrin signaling in vertebrate brain development are well established. Their involvement in the modulation of mammalian synaptic structure and physiology is also emerging. However, less is known of their effects on brain development and their function in adult invertebrate nervous systems. Here, we report on the characterization of Eph receptor and ephrin orthologs in the honeybee, Apis mellifera (Am), and their role in learning and memory. In situ h...

  3. Cocaine exposure modulates dopamine and adenosine signaling in the fetal brain

    OpenAIRE

    Kubrusly, Regina C. C.; Bhide, Pradeep G.

    2009-01-01

    Exposure to cocaine during the fetal period can produce significant lasting changes in the structure and function of the brain. Cocaine exerts its effects on the developing brain by blocking monoamine transporters and impairing monoamine receptor signaling. Dopamine is a major central target of cocaine. In a mouse model, we show that cocaine exposure from embryonic day 8 (E8) to E14 produces significant reduction in dopamine transporter activity, attenuation of dopamine D1-receptor function a...

  4. Prion Infection of Mouse Brain Reveals Multiple New Upregulated Genes Involved in Neuroinflammation or Signal Transduction

    OpenAIRE

    Carroll, James A.; Striebel, James F.; Race, Brent; Phillips, Katie; Chesebro, Bruce

    2014-01-01

    Gliosis is often a preclinical pathological finding in neurodegenerative diseases, including prion diseases, but the mechanisms facilitating gliosis and neuronal damage in these diseases are not understood. To expand our knowledge of the neuroinflammatory response in prion diseases, we assessed the expression of key genes and proteins involved in the inflammatory response and signal transduction in mouse brain at various times after scrapie infection. In brains of scrapie-infected mice at pre...

  5. Desired EEG Signals For Detecting Brain Tumor Using LMS Algorithm And Feedforward Network

    OpenAIRE

    Indu Sekhar Samant#1, Guru Kalyan Kanungo#2 , Santosh Kumar Mishra*3

    2012-01-01

    In Brain tumor diagnostic EEG is the most relevant in assesing how basic functionality is affected by the lesion.EEG continues to be an attractive tool in clinical practice due to its non invasiveness and real time depication of brain function. But the EEG signalcontains the useful information along with redundant or noise information. In this Paper Least Mean Square algorithm is used to remove the artifact in the EEG signal. , generic features present in the EEG signalare extracted using spe...

  6. Brain estrogen signaling and acute modulation of acoustic communication behaviors: a working hypothesis

    OpenAIRE

    Remage-Healey, Luke

    2012-01-01

    Although estrogens are widely considered circulating ‘sex steroid hormones’ typically associated with female reproduction, recent evidence suggests that estrogens can act as local modulators of brain circuits in both males and females. Functional implications of this newly-characterized estrogen signaling system have begun to emerge. This essay summarizes evidence in support of the hypothesis that the rapid production of estrogens in brain circuits can drive acute changes in both the producti...

  7. Sleep apnoea and the brain: a complex relationship.

    Science.gov (United States)

    Rosenzweig, Ivana; Glasser, Martin; Polsek, Dora; Leschziner, Guy D; Williams, Steve C R; Morrell, Mary J

    2015-05-01

    Intermittent hypoxia, reoxygenation, and hypercapnia or hypocapnia occur in both adults and children during untreated apnoea and hypopnoea, along with changes in cerebral blood flow and sleep fragmentation. These effects can result in cognitive deficits with functional effects on work and school efficiency. The assessment of how obstructive sleep apnoea affects cognition depends on the specificity and sensitivity of the tests, which are rarely developed specifically for obstructive sleep apnoea. In this Review, we discuss both the neural adaptive and maladaptive processes in response to hypoxaemia. The net result on cognitive and emotional performance depends on the stage of this dynamic process, effects on other body systems, cognitive reserve, and idiosyncratic susceptibility. We also explore the contribution of fragmented sleep, and the disruption of sleep structure, with focus on the effect at different times in the development of disease. This Review will address the gap in the underlying pathophysiology of new clinical and translational findings, and argue their contribution to the inherent complexity of the association between obstructive sleep apnoea and the brain. PMID:25887982

  8. Model of the Brain Tumor–Pumilio translation repressor complex

    Science.gov (United States)

    Edwards, Thomas A.; Wilkinson, Brian D.; Wharton, Robin P.; Aggarwal, Aneel K.

    2003-01-01

    The Brain Tumor (Brat) protein is recruited to the 3′ untranslated region (UTR) of hunchback mRNA to regulate its translation. Recruitment is mediated by interactions between the Pumilio RNA-binding Puf repeats and the NHL domain of Brat, a conserved structural motif present in a large family of growth regulators. In this report, we describe the crystal structure of the Brat NHL domain and present a model of the Pumilio–Brat complex derived from in silico docking experiments and supported by mutational analysis of the protein–protein interface. A key feature of the model is recognition of the outer, convex surface of the Pumilio Puf domain by the top, electropositive face of the six-bladed Brat β-propeller. In particular, an extended loop in Puf repeat 8 fits in the entrance to the central channel of the Brat β-propeller. Together, these interactions are likely to be prototypic of the recruitment strategies of other NHL-containing proteins in development. PMID:14561773

  9. Information theoretical quantification of cooperativity in signalling complexes

    Directory of Open Access Journals (Sweden)

    Ferkinghoff-Borg Jesper

    2009-01-01

    Full Text Available Abstract Background Intra-cellular information exchange, propelled by cascades of interacting signalling proteins, is essential for the proper functioning and survival of cells. Now that the interactome of several organisms is being mapped and several structural mechanisms of cooperativity at the molecular level in proteins have been elucidated, the formalization of this fundamental quantity, i.e. information, in these very diverse biological contexts becomes feasible. Results We show here that Shannon's mutual information quantifies information in biological system and more specifically the cooperativity inherent to the assembly of macromolecular complexes. We show how protein complexes can be considered as particular instances of noisy communication channels. Further we show, using a portion of the p27 regulatory pathway, how classical equilibrium thermodynamic quantities such as binding affinities and chemical potentials can be used to quantify information exchange but also to determine engineering properties such as channel noise and channel capacity. As such, this information measure identifies and quantifies those protein concentrations that render the biochemical system most effective in switching between the active and inactive state of the intracellular process. Conclusion The proposed framework provides a new and original approach to analyse the effects of cooperativity in the assembly of macromolecular complexes. It shows the conditions, provided by the protein concentrations, for which a particular system acts most effectively, i.e. exchanges the most information. As such this framework opens the possibility of grasping biological qualities such as system sensitivity, robustness or plasticity directly in terms of their effect on information exchange. Although these parameters might also be derived using classical thermodynamic parameters, a recasting of biological signalling in terms of information exchange offers an alternative

  10. A REVIEW ON INFLUENCE OF MUSIC ON BRAIN ACTIVITY USING SIGNAL PROCESSING AND IMAGING SYSTEM

    Directory of Open Access Journals (Sweden)

    Dr. K. ADALARASU,

    2011-04-01

    Full Text Available As per clinical neuroscience, listening to music involves many brain activities and its study has advanced greatly in the last thirty years. Research shows that music has significant effect on our body and mind. Music has a positive effect on the hormone system and allows the brain to concentrate more easily and assimilate more information in less time, thereby boosting learning and information intake and thus augmenting cognitive skills. Studies have found that the silence between two musical notes triggers brain cells and neurons which are responsible for the development of sharp memory. Music at different pitches (for example, Madhyamavati, Sankarabarnam raga and so on elicits exceptionally emotions and is capable ofreliably affecting the mood of individuals, which in turn changes the brain activity. This article provides a brief overview of currently available signal processing and imaging techniques to study the influence of different music on human brain activity.

  11. Entropy analyses of spatiotemporal synchronizations in brain signals from patients with focal epilepsies

    CERN Document Server

    Tuncay, Caglar

    2010-01-01

    The electroencephalographic (EEG) data intracerebrally recorded from 20 epileptic humans with different brain origins of focal epilepsies or types of seizures, ages and sexes are investigated (nearly 700 million data). Multi channel univariate amplitude analyses are performed and it is shown that time dependent Shannon entropies can be used to predict focal epileptic seizure onsets in different epileptogenic brain zones of different patients. Formations or time evolutions of the synchronizations in the brain signals from epileptogenic or non epileptogenic areas of the patients in ictal interval or inter-ictal interval are further investigated employing spatial or temporal differences of the entropies.

  12. Analysis of Brain Cognitive State for Arithmetic Task and Motor Task Using Electroencephalography Signal

    Directory of Open Access Journals (Sweden)

    R Kalpana

    2013-08-01

    Full Text Available To localize the brain dynamics for cognitive processes from EEG signature has been a challenging taskfrom last two decades. In this paper we explore the spatial-temporal correlations of brain electricalneuronal activity for cognitive task such as Arithmetic and Motor Task using 3D cortical distributionmethod. Ten healthy right handed volunteers participated in the experiment. EEG signal was acquiredduring resting state with eyes open and eyes closed; performing motor task and arithmetic calculations.The signal was then computed for three dimensional cortical distributions on realistic head model withMNI152 template using standardized low resolution brain electromagnetic tomography (sLORETA. Thiswas followed by an appropriate standardization of the current density, producing images of electricneuronal activity without localization bias. Neuronal generators responsible for cognitive state such asArithmetic Task and Motor Task were localized. The result was correlated with the previous neuroimaging(fMRI study investigation. Hence our result directed that the neuronal activity from EEG signal can bedemonstrated in cortical level with good spatial resolution. 3D cortical distribution method, thus, may beused to obtain both spatial and temporal information from EEG signal and may prove to be a significanttechnique to investigate the cognitive functions in mental health and brain dysfunctions. Also, it may behelpful for brain/human computer interfacing.

  13. The role of mTOR signalling in neurogenesis, insights from tuberous sclerosis complex.

    Science.gov (United States)

    Tee, Andrew R; Sampson, Julian R; Pal, Deb K; Bateman, Joseph M

    2016-04-01

    Understanding the development and function of the nervous system is one of the foremost aims of current biomedical research. The nervous system is generated during a relatively short period of intense neurogenesis that is orchestrated by a number of key molecular signalling pathways. Even subtle defects in the activity of these molecules can have serious repercussions resulting in neurological, neurodevelopmental and neurocognitive problems including epilepsy, intellectual disability and autism. Tuberous sclerosis complex (TSC) is a monogenic disease characterised by these problems and by the formation of benign tumours in multiple organs, including the brain. TSC is caused by mutations in the TSC1 or TSC2 gene leading to activation of the mechanistic target of rapamycin (mTOR) signalling pathway. A desire to understand the neurological manifestations of TSC has stimulated research into the role of the mTOR pathway in neurogenesis. In this review we describe TSC neurobiology and how the use of animal model systems has provided insights into the roles of mTOR signalling in neuronal differentiation and migration. Recent progress in this field has identified novel mTOR pathway components regulating neuronal differentiation. The roles of mTOR signalling and aberrant neurogenesis in epilepsy are also discussed. Continuing efforts to understand mTOR neurobiology will help to identify new therapeutic targets for TSC and other neurological diseases. PMID:26849906

  14. Magnetization transfer ratio measurements of the brain in children with tuberous sclerosis complex

    International Nuclear Information System (INIS)

    Magnetization transfer contrast and magnetization transfer ratio (MTR) in brain are mainly related to the presence of myelin. Neuropathological studies of brain lesions in tuberous sclerosis complex (TSC) have demonstrated disordered myelin sheaths. To evaluate the MTR of the brain in children with TSC and to compare with that in controls. Four patients (aged 0.41-8.4 years, mean 2.5 years) with TSC and four age- and sex-matched controls were evaluated with classic MR sequences and with a three-dimensional gradient-echo sequence without and with magnetization transfer pre-pulse. The MTR was calculated as: (SI0-SIm)/SI0 x 100%, where SIm refers to signal intensity from an image acquired with a magnetization transfer pre-pulse and SI0 the signal intensity from the image acquired without a magnetization transfer pre-pulse. The MTR values of cortical tubers (44.1±4.1), of subependymal nodules (51.6±4.8) and of white matter lesions (52.4±1.8) were significantly lower than those of cortex (58.7±3.53), of basal ganglia (caudate nucleus 58.2±2.8, putamen 59.6±2.5, thalamus 61.3±2.4) and of white matter (64.2±2.5) in controls (P<0.001). The MTR of normal-appearing white matter (61.2±3.0) in patients was lower than that of white matter in controls (P<0.01). The MTR of cortex and basal ganglia in patients was not significantly different from that in controls. MTR measurements not only provide semiquantitative information for TSC lesions but also reveal more extensive disease. (orig.)

  15. Magnetization transfer ratio measurements of the brain in children with tuberous sclerosis complex

    Energy Technology Data Exchange (ETDEWEB)

    Zikou, Anastasia; Ioannidou, Maria-Christina; Astrakas, Loukas; Argyropoulou, Maria I. [University of Ioannina, Department of Radiology, Medical School, Ioannina (Greece); Tzoufi, Meropi [University of Ioannina, Child Health Department, Medical School, Ioannina (Greece)

    2005-11-01

    Magnetization transfer contrast and magnetization transfer ratio (MTR) in brain are mainly related to the presence of myelin. Neuropathological studies of brain lesions in tuberous sclerosis complex (TSC) have demonstrated disordered myelin sheaths. To evaluate the MTR of the brain in children with TSC and to compare with that in controls. Four patients (aged 0.41-8.4 years, mean 2.5 years) with TSC and four age- and sex-matched controls were evaluated with classic MR sequences and with a three-dimensional gradient-echo sequence without and with magnetization transfer pre-pulse. The MTR was calculated as: (SI{sub 0}-SI{sub m})/SI{sub 0} x 100%, where SI{sub m} refers to signal intensity from an image acquired with a magnetization transfer pre-pulse and SI{sub 0} the signal intensity from the image acquired without a magnetization transfer pre-pulse. The MTR values of cortical tubers (44.1{+-}4.1), of subependymal nodules (51.6{+-}4.8) and of white matter lesions (52.4{+-}1.8) were significantly lower than those of cortex (58.7{+-}3.53), of basal ganglia (caudate nucleus 58.2{+-}2.8, putamen 59.6{+-}2.5, thalamus 61.3{+-}2.4) and of white matter (64.2{+-}2.5) in controls (P<0.001). The MTR of normal-appearing white matter (61.2{+-}3.0) in patients was lower than that of white matter in controls (P<0.01). The MTR of cortex and basal ganglia in patients was not significantly different from that in controls. MTR measurements not only provide semiquantitative information for TSC lesions but also reveal more extensive disease. (orig.)

  16. Automatic integration of confidence in the brain valuation signal.

    Science.gov (United States)

    Lebreton, Maël; Abitbol, Raphaëlle; Daunizeau, Jean; Pessiglione, Mathias

    2015-08-01

    A key process in decision-making is estimating the value of possible outcomes. Growing evidence suggests that different types of values are automatically encoded in the ventromedial prefrontal cortex (VMPFC). Here we extend this idea by suggesting that any overt judgment is accompanied by a second-order valuation (a confidence estimate), which is also automatically incorporated in VMPFC activity. In accordance with the predictions of our normative model of rating tasks, two behavioral experiments showed that confidence levels were quadratically related to first-order judgments (age, value or probability ratings). The analysis of three functional magnetic resonance imaging data sets using similar rating tasks confirmed that the quadratic extension of first-order ratings (our proxy for confidence) was encoded in VMPFC activity, even if no confidence judgment was required of the participants. Such an automatic aggregation of value and confidence in a same brain region might provide insight into many distortions of judgment and choice. PMID:26192748

  17. Extracellular signal regulated kinases 1/2 signal pathway and responses of astrocytes after diffuse brain injury

    Institute of Scientific and Technical Information of China (English)

    Jinxing Li; Haimei Zhao; Yu Li; Chong Wang; Jiashan Zhao; Xianli Zhu

    2007-01-01

    BACKGROUND: The treatment of diffuse brain injury during an acute period is focused on relieving degrees of secondary brain injury. Generation and development of pathological changes of secondary brain injury depend on signal conduction, so down-regulating over response of astrocyte through interfering a key link of signal conduction pathway may bring a new thinking for the treatment of diffuse brain injury. OBJECTIVE: To observe the effect of over activity of extracellular signal regulated kinases 1/2 (ERK1/2) signal pathway on the response of astrocyte during an acute period of diffuse brain injury. DESIGN: Completely randomized grouping and controlled animal study.SETTINGS: Department of Neurosurgery, the Third Affiliated Hospital, Nanchang University; Department of Neurosurgery, Union Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology.MATERIALS: A total of 158 healthy male SD rats, of 11 weeks old, weighing 320 - 370 g, were provided by Experimental Animal Faulty, Tongji Medical College, Huazhong University of Science and Technology. Rabbit-anti-phosphorylated ERK1/2 (pERKl/2) polyclonal antibody was provided by R&D Company; rabbit-anti-glial fibrillary acidic protein (GFAP) polyclonal antibody, SP immunohistochemical kit and horseradish peroxidase (HRP)-labeled goat-anti-rabbit IgG by Santa Cruz Company; specific inhibitor U0126 of ERK1/2 signal pathway by Alexis Company. METHODS: The experiment was carried out in the Laboratory of Neurosurgery, Union Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology from September 2004 to March 2006. ①Detection of pERKl/2 expression: A total of 110 rats were randomly divided into sham operation group (n =5), model group (n =35), high-dosage U0126 group (n =35) and low-dosage U0126 group (n =35). Rats in the sham operation group were only treated with incision of epicranium and fixation of backup plate, but not hit. Rats in the model group

  18. Structural permeability of complex networks to control signals

    Science.gov (United States)

    Lo Iudice, Francesco; Garofalo, Franco; Sorrentino, Francesco

    2015-09-01

    Many biological, social and technological systems can be described as complex networks. The goal of affecting their behaviour has motivated recent work focusing on the relationship between the network structure and its propensity to be controlled. While this work has provided insight into several relevant problems, a comprehensive approach to address partial and complete controllability of networks is still lacking. Here, we bridge this gap by developing a framework to maximize the diffusion of the control signals through a network, while taking into account physical and economic constraints that inevitably arise in applications. This approach allows us to introduce the network permeability, a unified metric of the propensity of a network to be controllable. The analysis of the permeability of several synthetic and real networks enables us to extract some structural features that deepen our quantitative understanding of the ease with which specific controllability requirements can be met.

  19. Tracking of electroencephalography signals across brain lobes using motion estimation and cross-correlation

    Science.gov (United States)

    Lim, Seng Hooi; Nisar, Humaira; Yap, Vooi Voon; Shim, Seong-O.

    2015-11-01

    Electroencephalography (EEG) is the signal generated by electrical activity in the human brain. EEG topographic maps (topo-maps) give an idea of brain activation. Functional connectivity helps to find functionally integrated relationship between spatially separated brain regions. Brain connectivity can be measured by several methods. The classical methods calculate the coherence and correlation of the signal. We have developed an algorithm to map functional neural connectivity in the brain by using a full search block matching motion estimation algorithm. We have used oddball paradigm to examine the flow of activation across brain lobes for a specific activity. In the first step, the EEG signal is converted into topo-maps. The flow of activation between consecutive frames is tracked using full search block motion estimation, which appears in the form of motion vectors. In the second step, vector median filtering is used to obtain a smooth motion field by removing the unwanted noise. For each topo-map, several activation paths are tracked across various brain lobes. We have also developed correlation activity maps by following the correlation coefficient paths between electrodes. These paths are selected when the correlation coefficient between electrodes is >70%. We have compared the motion estimation path with the correlation coefficient activation maps. The tracked paths obtained by using motion estimation and correlation give very similar results. The inter-subject comparison shows that four out of five subjects tracked path involves all four (occipital, temporal, parietal, frontal) brain lobes for the same stimuli. The intra-subject analysis shows that three out of five subjects show different tracked lobes for different stimuli.

  20. Identification and analysis of signaling networks potentially involved in breast carcinoma metastasis to the brain.

    Directory of Open Access Journals (Sweden)

    Feng Li

    Full Text Available Brain is a common site of breast cancer metastasis associated with significant neurologic morbidity, decreased quality of life, and greatly shortened survival. However, the molecular and cellular mechanisms underpinning brain colonization by breast carcinoma cells are poorly understood. Here, we used 2D-DIGE (Difference in Gel Electrophoresis proteomic analysis followed by LC-tandem mass spectrometry to identify the proteins differentially expressed in brain-targeting breast carcinoma cells (MB231-Br compared with parental MDA-MB-231 cell line. Between the two cell lines, we identified 12 proteins consistently exhibiting greater than 2-fold (p<0.05 difference in expression, which were associated by the Ingenuity Pathway Analysis (IPA with two major signaling networks involving TNFα/TGFβ-, NFκB-, HSP-70-, TP53-, and IFNγ-associated pathways. Remarkably, highly related networks were revealed by the IPA analysis of a list of 19 brain-metastasis-associated proteins identified recently by the group of Dr. A. Sierra using MDA-MB-435-based experimental system (Martin et al., J Proteome Res 2008 7:908-20, or a 17-gene classifier associated with breast cancer brain relapse reported by the group of Dr. J. Massague based on a microarray analysis of clinically annotated breast tumors from 368 patients (Bos et al., Nature 2009 459: 1005-9. These findings, showing that different experimental systems and approaches (2D-DIGE proteomics used on brain targeting cell lines or gene expression analysis of patient samples with documented brain relapse yield highly related signaling networks, suggest strongly that these signaling networks could be essential for a successful colonization of the brain by metastatic breast carcinoma cells.

  1. Emergence Of Consciousness And Qualia From A Complex Brain

    Directory of Open Access Journals (Sweden)

    Korf Jakob

    2014-12-01

    Full Text Available Qualia are private conscious experiences of which the associated feelings can be reported to other people. Whether qualia are amenable to scientific exploration has often been questioned, which is challenged by the present article. The following arguments are given: 1. the configuration of the brain changes continuously and irreversibly, because of genetic and environmental influences and interhuman communication; 2. qualia and consciousness are processes, rather than states; 3. private feelings, including those associated with qualia, should be positioned in the context of a personal brain as being developed during life; 4. consciousness and qualia should be understood in the context of general system theory, thus concluding that isolated, in vitro, properties of neurons and other brain constituents might marginally contribute to the understanding of higher brain functions, mind or qualia; 5. current in vivo approaches have too little resolution power - in terms of space and time - to delineate individual and subjective brain processes.

  2. Caveolins: Targeting Pro-survival Signaling in the Heart and Brain

    OpenAIRE

    CreedM.Stary; YasuoM.Tsutsumi

    2012-01-01

    The present review discusses intracellular signaling moieties specific to membrane lipid rafts (MLRs) and the scaffolding proteins caveolin and introduces current data promoting their potential role in the treatment of pathologies of the heart and brain. MLRs are discreet microdomains of the plasma membrane enriched in gylcosphingolipids and cholesterol that concentrate and localize signaling molecules. Caveolin proteins are necessary for the formation of MLRs, and are responsible for coordi...

  3. Caveolins: targeting pro-survival signaling in the heart and brain

    OpenAIRE

    Creed M. Stary; Tsutsumi, Yasuo M.; Patel, Piyush M.; Head, Brian P.; Hemal H. Patel; Roth, David M.

    2012-01-01

    The present review discusses intracellular signaling moieties specific to membrane lipid rafts (MLRs) and the scaffolding proteins caveolin and introduces current data promoting their potential role in the treatment of pathologies of the heart and brain. MLRs are discreet microdomains of the plasma membrane enriched in gylcosphingolipids and cholesterol that concentrate and localize signaling molecules. Caveolin proteins are necessary for the formation of MLRs, and are responsible for coordin...

  4. Mitochondria are the source of hydrogen peroxide for dynamic brain-cell signaling

    OpenAIRE

    Bao, Li; Avshalumov, Marat V.; Patel, Jyoti C.; Lee, Christian R.; Miller, Evan W.; Chang, Christopher J.; Rice, Margaret E.

    2009-01-01

    Hydrogen peroxide (H2O2) is emerging as a ubiquitous small-molecule messenger in biology, particularly in the brain, but underlying mechanisms of peroxide signaling remain an open frontier for study. For example, dynamic dopamine transmission in dorsolateral striatum is regulated on a subsecond timescale by glutamate via H2O2 signaling, which activates ATP-sensitive potassium (KATP) channels to inhibit dopamine release. However, the origin of this modulatory H2O2 has been elusive. Here we add...

  5. Development of a Brain Computer Interface (BCI) Speller System Based on SSVEP Signals

    OpenAIRE

    Movahedi, Mohammad Mehdi; Mehdizadeh, Alireza; Alipour, Abolfazl

    2013-01-01

    BCI is one of the most intriguing technologies among other HCI systems, mostly because of its capability of recording brain activities. Spelling BCIs, which help paralyzed people to maintain communication, are one of the striking topics in the field of BCI. In this scientific a spelling BCI system with high transfer rate and accuracy that uses SSVEP signals is proposed. In addition, we suggested that LED light sources can provide proper signals for speller BCIs and they can be used in future.

  6. In vivo astrocytic Ca2+ signaling in health and brain disorders

    OpenAIRE

    Ding, Shinghua

    2013-01-01

    Astrocytes are the predominant glial cell type in the CNS. Although astrocytes are electrically nonexcitable, their excitability is manifested by their Ca2+ signaling, which serves as a mediator of neuron–glia bidirectional interactions via tripartite synapses. Studies from in vivo two-photon imaging indicate that in healthy animals, the properties of spontaneous astrocytic Ca2+ signaling are affected by animal species, age, wakefulness and the location of astrocytes in the brain. Intercellul...

  7. Recovering fNIRS brain signals: physiological interference suppression with independent component analysis

    Science.gov (United States)

    Zhang, Y.; Shi, M.; Sun, J.; Yang, C.; Zhang, Yajuan; Scopesi, F.; Makobore, P.; Chin, C.; Serra, G.; Wickramasinghe, Y. A. B. D.; Rolfe, P.

    2015-02-01

    Brain activity can be monitored non-invasively by functional near-infrared spectroscopy (fNIRS), which has several advantages in comparison with other methods, such as flexibility, portability, low cost and fewer physical restrictions. However, in practice fNIRS measurements are often contaminated by physiological interference arising from cardiac contraction, breathing and blood pressure fluctuations, thereby severely limiting the utility of the method. Hence, further improvement is necessary to reduce or eliminate such interference in order that the evoked brain activity information can be extracted reliably from fNIRS data. In the present paper, the multi-distance fNIRS probe configuration has been adopted. The short-distance fNIRS measurement is treated as the virtual channel and the long-distance fNIRS measurement is treated as the measurement channel. Independent component analysis (ICA) is employed for the fNIRS recordings to separate the brain signals and the interference. Least-absolute deviation (LAD) estimator is employed to recover the brain activity signals. We also utilized Monte Carlo simulations based on a five-layer model of the adult human head to evaluate our methodology. The results demonstrate that the ICA algorithm has the potential to separate physiological interference in fNIRS data and the LAD estimator could be a useful criterion to recover the brain activity signals.

  8. Beacon signal in transcranial color coded ultrasound: A sign for brain death

    Directory of Open Access Journals (Sweden)

    Mehmet Akif Topçuoğlu

    2014-04-01

    Full Text Available A widely under-recognized brain-death confirming transcranial ultrasonography pattern resembling the red-blue beacon signal was demonstrated. Familiarity to this distinct and characteristic ultrasonic pattern seems to be important in the perspective of point-of-care neurological ultrasound use and knobology.

  9. Intelligent Technique for Signal Processing to Identify the Brain Disorder for Epilepsy Captures Using Fuzzy Systems

    Directory of Open Access Journals (Sweden)

    Gurumurthy Sasikumar

    2016-01-01

    Full Text Available The new direction of understand the signal that is created from the brain organization is one of the main chores in the brain signal processing. Amid all the neurological disorders the human brain epilepsy is measured as one of the extreme prevalent and then programmed artificial intelligence detection technique is an essential due to the crooked and unpredictable nature of happening of epileptic seizures. We proposed an Improved Fuzzy firefly algorithm, which would enhance the classification of the brain signal efficiently with minimum iteration. An important bunching technique created on fuzzy logic is the Fuzzy C means. Together in the feature domain with the spatial domain the features gained after multichannel EEG signals remained combined by means of fuzzy algorithms. And for better precision segmentation process the firefly algorithm is applied to optimize the Fuzzy C-means membership function. Simultaneously for the efficient clustering method the convergence criteria are set. On the whole the proposed technique yields more accurate results and that gives an edge over other techniques. This proposed algorithm result compared with other algorithms like fuzzy c means algorithm and PSO algorithm.

  10. Tryptophan as an evolutionarily conserved signal to brain serotonin : Molecular evidence and psychiatric implications

    NARCIS (Netherlands)

    Russo, Sascha; Kema, Ido P.; Bosker, Fokko; Haavik, Jan; Korf, Jakob

    2009-01-01

    The role of serotonin (5-HT) in psychopathology has been investigated for decades. Among others, symptoms of depression, panic, aggression and suicidality have been associated with serotonergic dysfunction. Here we summarize the evidence that low brain 5-HT signals a metabolic imbalance that is evol

  11. Toll-like receptor 2 signaling in response to brain injury: an innate bridge to neuroinflammation

    DEFF Research Database (Denmark)

    Babcock, Alicia; Wirenfeldt, Martin; Holm, Thomas;

    2006-01-01

    -mutant mice. Consistent with the fact that responses in knock-out mice had all returned to wild-type levels by 8 d, there was no evidence for effects on neuronal plasticity at 20 d. These results identify a role for TLR2 signaling in the early glial response to brain injury, acting as an innate bridge to...

  12. Beacon signal in transcranial color coded ultrasound: A sign for brain death

    OpenAIRE

    Mehmet Akif Topçuoğlu; Ethem Murat Arsava

    2014-01-01

    A widely under-recognized brain-death confirming transcranial ultrasonography pattern resembling the red-blue beacon signal was demonstrated. Familiarity to this distinct and characteristic ultrasonic pattern seems to be important in the perspective of point-of-care neurological ultrasound use and knobology.

  13. Detecting stable phase structures in EEG signals to classify brain activity amplitude patterns

    Institute of Scientific and Technical Information of China (English)

    Yusely RUIZ; Guang LI; Walter J. FREEMAN; Eduardo GONZALEZ

    2009-01-01

    Obtaining an electrocorticograms (ECoG) signal requires an invasive procedure in which brain activity is recorded from the cortical surface. In contrast, obtaining electroencephalograms (EEG) recordings requires the non-invasive procedure of recording the brain activity from the scalp surface, which allows EEG recordings to be performed more easily on healthy humans. In this work, a technique previously used to study spatial-temporal patterns of brain activity on animal ECoG was adapted for use on EEG. The main issues are centered on solving the problems introduced by the increment on the interelectrode distance and the procedure to detect stable frames. The results showed that spatial patterns of beta and gamma activity can also be extracted from the EEG signal by using stable frames as time markers for feature extraction. This adapted technique makes it possible to take advantage of the cognitive and phenomenological awareness of a normal healthy subject.

  14. Secondary instabilities modulate cortical complexity in the mammalian brain

    OpenAIRE

    Budday, Silvia; Steinmann, Paul; Kuhl, Ellen

    2015-01-01

    Disclosing the origin of convolutions in the mammalian brain remains a scientific challenge. Primary folds form before we are born: they are static, well defined, and highly preserved across individuals. Secondary folds occur and disappear throughout our entire life time: they are dynamic, irregular, and highly variable among individuals. While extensive research has improved our understanding of primary folding in the mammalian brain, secondary folding remains understudied and poorly underst...

  15. Sleeping of a Complex Brain Networks with Hierarchical Organization

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ying-Yue; YANG Qiu-Ying; CHEN Tian-Lun

    2009-01-01

    The dynamical behavior in the cortical brain network of macaque is studied by modeling each cortical area with a subnetwork of interacting excitable neurons. We characterize the system by studying how to perform the transition, which is now topology-dependent, from the active state to that with no activity. This could be a naive model for the wakening and sleeping of a brain-like system, i.e., a multi-component system with two different dynamical behavior.

  16. An Adaptive Complex Network Model for Brain Functional Networks

    OpenAIRE

    Gomez Portillo, Ignacio J.; Gleiser, Pablo M.

    2009-01-01

    Brain functional networks are graph representations of activity in the brain, where the vertices represent anatomical regions and the edges their functional connectivity. These networks present a robust small world topological structure, characterized by highly integrated modules connected sparsely by long range links. Recent studies showed that other topological properties such as the degree distribution and the presence (or absence) of a hierarchical structure are not robust, and show diffe...

  17. On the Complexity of Brain Disorders: A Symptom-Based Approach.

    Science.gov (United States)

    Moustafa, Ahmed A; Phillips, Joseph; Kéri, Szabolcs; Misiak, Blazej; Frydecka, Dorota

    2016-01-01

    Mounting evidence shows that brain disorders involve multiple and different neural dysfunctions, including regional brain damage, change to cell structure, chemical imbalance, and/or connectivity loss among different brain regions. Understanding the complexity of brain disorders can help us map these neural dysfunctions to different symptom clusters as well as understand subcategories of different brain disorders. Here, we discuss data on the mapping of symptom clusters to different neural dysfunctions using examples from brain disorders such as major depressive disorder (MDD), Parkinson's disease (PD), schizophrenia, posttraumatic stress disorder (PTSD) and Alzheimer's disease (AD). In addition, we discuss data on the similarities of symptoms in different disorders. Importantly, computational modeling work may be able to shed light on plausible links between various symptoms and neural damage in brain disorders. PMID:26941635

  18. Predict or classify: The deceptive role of time-locking in brain signal classification

    CERN Document Server

    Rusconi, Marco

    2016-01-01

    Several experimental studies claim to be able to predict the outcome of simple decisions from brain signals measured before subjects are aware of their decision. Often, these studies use multivariate pattern recognition methods with the underlying assumption that the ability to classify the brain signal is equivalent to predict the decision itself. Here we show instead that it is possible to correctly classify a signal even if it does not contain any predictive information about the decision. We first define a simple stochastic model that mimics the random decision process between two equivalent alternatives, and generate a large number of independent trials that contain no choice-predictive information. The trials are first time-locked to the time point of the final event and then classified using standard machine-learning techniques. The resulting classification accuracy is above chance level long before the time point of time-locking. We then analyze the same trials using information theory. We demonstrate...

  19. Close relationship between fMRI signals and transient heart rate changes accompanying K-complex. Simultaneous EEG/fMRI study

    International Nuclear Information System (INIS)

    Combining functional magnetic resonance imaging (fMRI) and electroencephalography (EEG) allows the investigation of spontaneous activities in the human brain. Recently, by using this technique, increases in fMRI signal accompanying transient EEG activities such as sleep spindles and slow waves were reported. Although these fMRI signal increases appear to arise as a result of the neural activities being reflected in the EEG, when the influence of physiological activities upon fMRI signals are taken into consideration, it is highly controversial that fMRI signal increases accompanying transient EEG activities reflect actual neural activities. In the present study, we conducted simultaneous fMRI and polysomnograph recording of 18 normal adults, to study the effect of transient heart rate changes after a K-complex on fMRI signals. Significant fMRI signal increase was observed in the cerebellum, the ventral thalamus, the dorsal part of the brainstem, the periventricular white matter and the ventricle (quadrigeminal cistern). On the other hand, significant fMRI signal decrease was observed only in the right insula. Moreover, intensities of fMRI signal increase that was accompanied by a K-complex correlated positively with the magnitude of heart rate changes after a K-complex. Previous studies have reported that K-complex is closely related with sympathetic nervous activity and that the attributes of perfusion regulation in the brain differ during wakefulness and sleep. By taking these findings into consideration, our present results indicate that a close relationship exists between a K-complex and the changes in cardio- and neurovascular regulations that are mediated by the autonomic nervous system during sleep; further, these results indicate that transient heart rate changes after a K-complex can affect the fMRI signal generated in certain brain regions. (author)

  20. A 'complex' of brain metabolites distinguish altered chemistry in the cingulate cortex of episodic migraine patients.

    Science.gov (United States)

    Becerra, L; Veggeberg, R; Prescot, A; Jensen, J E; Renshaw, P; Scrivani, S; Spierings, E L H; Burstein, R; Borsook, D

    2016-01-01

    Despite the prevalence of migraine, the pathophysiology of the disease remains unclear. Current understanding of migraine has alluded to the possibility of a hyperexcitable brain. The aim of the current study is to investigate human brain metabolite differences in the anterior cingulate cortex (ACC) during the interictal phase in migraine patients. We hypothesized that there may be differences in levels of excitatory neurotransmitters and/or their derivatives in the migraine cohort in support of the theory of hyperexcitability in migraine. 2D J-resolved proton magnetic resonance spectroscopy ((1)H-MRS) data were acquired on a 3 Tesla (3 T) MRI from a voxel placed over the ACC of 32 migraine patients (MP; 23 females, 9 males, age 33 ± 9.6 years) and 33 healthy controls (HC; 25 females, 8 males, age 32 ± 9.6 years). Amplitude correlation matrices were constructed for each subject to evaluate metabolite discriminability. ProFit-estimated metabolite peak areas were normalized to a water reference signal to assess subject differences. The initial analysis of variance (ANOVA) was performed to test for group differences for all metabolites/creatine (Cre) ratios between healthy controls and migraineurs but showed no statistically significant differences. In addition, we used a multivariate approach to distinguish migraineurs from healthy subjects based on the metabolite/Cre ratio. A quadratic discriminant analysis (QDA) model was used to identify 3 metabolite ratios sufficient to minimize minimum classification error (MCE). The 3 selected metabolite ratios were aspartate (Asp)/Cre, N-acetyl aspartate (NAA)/Cre, and glutamine (Gln)/Cre. These findings are in support of a 'complex' of metabolite alterations, which may underlie changes in neuronal chemistry in the migraine brain. Furthermore, the parallel changes in the three-metabolite 'complex' may confer more subtle but biological processes that are ongoing. The data also support the current theory that the

  1. Emergence Of Consciousness And Qualia From A Complex Brain.

    Science.gov (United States)

    Korf, Jakob

    2014-01-01

    Qualia are private conscious experiences of which the associated feelings can be reported to other people. Whether qualia are amenable to scientific exploration has often been questioned, which is challenged by the present article. The following arguments are given: 1. the configuration of the brain changes continuously and irreversibly, because of genetic and environmental influences and interhuman communication; 2. qualia and consciousness are processes, rather than states; 3. private feelings, including those associated with qualia, should be positioned in the context of a personal brain as being developed during life; 4. consciousness and qualia should be understood in the context of general system theory, thus concluding that isolated, in vitro, properties of neurons and other brain constituents might marginally contribute to the understanding of higher brain functions, mind or qualia; 5. current in vivo approaches have too little resolution power - in terms of space and time - to delineate individual and subjective brain processes. When subtle personalized properties of the nervous system can be assessed in vivo or in vitro, qualia can scientifically be investigated. We discuss some approaches to overcome these barriers. PMID:26444360

  2. Notching on cancer’s door: Notch signaling in brain tumors

    Directory of Open Access Journals (Sweden)

    Marcin eTeodorczyk

    2015-01-01

    Full Text Available Notch receptors play an essential role in the regulation of central cellular processes during embryonic and postnatal development. The mammalian genome encodes for four Notch paralogs (Notch 1-4, which are activated by three Delta-like (Dll1/3/4 and two Serrate-like (Jagged1/2 ligands. Further, non-canonical Notch ligands such as EGFL7 have been identified and serve mostly as antagonists of Notch signaling. The Notch pathway prevents neuronal differentiation in the central nervous system by driving neural stem cell maintenance and commitment of neural progenitor cells into the glial lineage. Notch is therefore often implicated in the development of brain tumors, as tumor cells share various characteristics with neural stem and progenitor cells. Notch receptors are overexpressed in gliomas and their oncogenicity has been confirmed by gain- and loss-of-function studies in vitro and in vivo. To this end, special attention is paid to the impact of Notch signaling on stem-like brain tumor-propagating cells as these cells contribute to growth, survival, invasion and recurrence of brain tumors. Based on the outcome of ongoing studies in vivo, Notch-directed therapies such as γ secretase inhibitors and blocking antibodies have entered and completed various clinical trials. This review summarizes the current knowledge on Notch signaling in brain tumor formation and therapy.

  3. The influence of complex and threatening environments in early life on brain size and behaviour

    OpenAIRE

    DePasquale, C.; Neuberger, T.; Hirrlinger, A. M.; Braithwaite, V. A.

    2016-01-01

    The ways in which challenging environments during development shape the brain and behaviour are increasingly being addressed. To date, studies typically consider only single variables, but the real world is more complex. Many factors simultaneously affect the brain and behaviour, and whether these work independently or interact remains untested. To address this, zebrafish (Danio rerio) were reared in a two-by-two design in housing that varied in structural complexity and/or exposure to a stre...

  4. Complex brain networks: From topological communities to clustered dynamics

    Indian Academy of Sciences (India)

    Lucia Zemanová; Gorka Zamora-López; Changsong Zhou; Jürgen Kurths

    2008-06-01

    Recent research has revealed a rich and complicated network topology in the cortical connectivity of mammalian brains. A challenging task is to understand the implications of such network structures on the functional organisation of the brain activities. We investigate synchronisation dynamics on the corticocortical network of the cat by modelling each node of the network (cortical area) with a subnetwork of interacting excitable neurons. We find that this network of networks displays clustered synchronisation behaviour and the dynamical clusters closely coincide with the topological community structures observed in the anatomical network. The correlation between the firing rate of the areas and the areal intensity is additionally examined. Our results provide insights into the relationship between the global organisation and the functional specialisation of the brain cortex.

  5. Insulin Regulates Hepatic Triglyceride Secretion and Lipid Content via Signaling in the Brain.

    Science.gov (United States)

    Scherer, Thomas; Lindtner, Claudia; O'Hare, James; Hackl, Martina; Zielinski, Elizabeth; Freudenthaler, Angelika; Baumgartner-Parzer, Sabina; Tödter, Klaus; Heeren, Joerg; Krššák, Martin; Scheja, Ludger; Fürnsinn, Clemens; Buettner, Christoph

    2016-06-01

    Hepatic steatosis is common in obesity and insulin resistance and results from a net retention of lipids in the liver. A key mechanism to prevent steatosis is to increase secretion of triglycerides (TG) packaged as VLDLs. Insulin controls nutrient partitioning via signaling through its cognate receptor in peripheral target organs such as liver, muscle, and adipose tissue and via signaling in the central nervous system (CNS) to orchestrate organ cross talk. While hepatic insulin signaling is known to suppress VLDL production from the liver, it is unknown whether brain insulin signaling independently regulates hepatic VLDL secretion. Here, we show that in conscious, unrestrained male Sprague Dawley rats the infusion of insulin into the third ventricle acutely increased hepatic TG secretion. Chronic infusion of insulin into the CNS via osmotic minipumps reduced the hepatic lipid content as assessed by noninvasive (1)H-MRS and lipid profiling independent of changes in hepatic de novo lipogenesis and food intake. In mice that lack the insulin receptor in the brain, hepatic TG secretion was reduced compared with wild-type littermate controls. These studies identify brain insulin as an important permissive factor in hepatic VLDL secretion that protects against hepatic steatosis. PMID:26861781

  6. Bispectral pairwise interacting source analysis for identifying systems of cross-frequency interacting brain sources from electroencephalographic or magnetoencephalographic signals

    Science.gov (United States)

    Chella, Federico; Pizzella, Vittorio; Zappasodi, Filippo; Nolte, Guido; Marzetti, Laura

    2016-05-01

    Brain cognitive functions arise through the coordinated activity of several brain regions, which actually form complex dynamical systems operating at multiple frequencies. These systems often consist of interacting subsystems, whose characterization is of importance for a complete understanding of the brain interaction processes. To address this issue, we present a technique, namely the bispectral pairwise interacting source analysis (biPISA), for analyzing systems of cross-frequency interacting brain sources when multichannel electroencephalographic (EEG) or magnetoencephalographic (MEG) data are available. Specifically, the biPISA makes it possible to identify one or many subsystems of cross-frequency interacting sources by decomposing the antisymmetric components of the cross-bispectra between EEG or MEG signals, based on the assumption that interactions are pairwise. Thanks to the properties of the antisymmetric components of the cross-bispectra, biPISA is also robust to spurious interactions arising from mixing artifacts, i.e., volume conduction or field spread, which always affect EEG or MEG functional connectivity estimates. This method is an extension of the pairwise interacting source analysis (PISA), which was originally introduced for investigating interactions at the same frequency, to the study of cross-frequency interactions. The effectiveness of this approach is demonstrated in simulations for up to three interacting source pairs and for real MEG recordings of spontaneous brain activity. Simulations show that the performances of biPISA in estimating the phase difference between the interacting sources are affected by the increasing level of noise rather than by the number of the interacting subsystems. The analysis of real MEG data reveals an interaction between two pairs of sources of central mu and beta rhythms, localizing in the proximity of the left and right central sulci.

  7. Complex courtship displays facilitate male reproductive success and plasticity in signaling across variable environments

    Institute of Scientific and Technical Information of China (English)

    Dustin J.WILGERS; Eileen A.HEBETS

    2011-01-01

    Effective signal transmission is essential for communication.In environments where signal transmission is highly variable,signalers may utilize complex signals,which incorporate multiple components and modalities,to maintain effective communication.Male Rabidosa rabida wolf spiders produce complex courtship signals,consisting of both visual and seismic components.We test the hypothesis that the complex signaling of R.rabida contributes to male reproductive success in variable signaling environments.We first examine the condition-dependence of foreleg ornamentation(a presumed visual signal)and seismic signal components and find that both may provide potentially redundant information on foraging history.Next,we assessed reproductive success across manipulated signaling environments that varied in the effectiveness of visual and/or seismic signal transmission.in environmenis where only one signal could be successfully transmitted(e.g.,visual or seismic),pairs were still able to successfully copulate.Additionally,we found that males altered their courtship display depending on the current signaling environment.Specifically,males reduced their use of a visual display component in signaling environments where visual signal transmission was ablated.Incorporating signals in multiple modalities not only enables R.rabida males to maintain copulation success across variable signaiing environments,but it also enables males to adjust their composite courtship display to current signaling conditions.

  8. Learning about brain physiology and complexity from the study of the epilepsies

    Directory of Open Access Journals (Sweden)

    N. Garcia-Cairasco

    2009-01-01

    Full Text Available The brain is a complex system, which produces emergent properties such as those associated with activity-dependent plasticity in processes of learning and memory. Therefore, understanding the integrated structures and functions of the brain is well beyond the scope of either superficial or extremely reductionistic approaches. Although a combination of zoom-in and zoom-out strategies is desirable when the brain is studied, constructing the appropriate interfaces to connect all levels of analysis is one of the most difficult challenges of contemporary neuroscience. Is it possible to build appropriate models of brain function and dysfunctions with computational tools? Among the best-known brain dysfunctions, epilepsies are neurological syndromes that reach a variety of networks, from widespread anatomical brain circuits to local molecular environments. One logical question would be: are those complex brain networks always producing maladaptive emergent properties compatible with epileptogenic substrates? The present review will deal with this question and will try to answer it by illustrating several points from the literature and from our laboratory data, with examples at the behavioral, electrophysiological, cellular and molecular levels. We conclude that, because the brain is a complex system compatible with the production of emergent properties, including plasticity, its functions should be approached using an integrated view. Concepts such as brain networks, graphics theory, neuroinformatics, and e-neuroscience are discussed as new transdisciplinary approaches dealing with the continuous growth of information about brain physiology and its dysfunctions. The epilepsies are discussed as neurobiological models of complex systems displaying maladaptive plasticity.

  9. Complexity of cardiac signals for predicting changes in alpha-waves after stress in patients undergoing cardiac catheterization

    Science.gov (United States)

    Chiu, Hung-Chih; Lin, Yen-Hung; Lo, Men-Tzung; Tang, Sung-Chun; Wang, Tzung-Dau; Lu, Hung-Chun; Ho, Yi-Lwun; Ma, Hsi-Pin; Peng, Chung-Kang

    2015-08-01

    The hierarchical interaction between electrical signals of the brain and heart is not fully understood. We hypothesized that the complexity of cardiac electrical activity can be used to predict changes in encephalic electricity after stress. Most methods for analyzing the interaction between the heart rate variability (HRV) and electroencephalography (EEG) require a computation-intensive mathematical model. To overcome these limitations and increase the predictive accuracy of human relaxing states, we developed a method to test our hypothesis. In addition to routine linear analysis, multiscale entropy and detrended fluctuation analysis of the HRV were used to quantify nonstationary and nonlinear dynamic changes in the heart rate time series. Short-time Fourier transform was applied to quantify the power of EEG. The clinical, HRV, and EEG parameters of postcatheterization EEG alpha waves were analyzed using change-score analysis and generalized additive models. In conclusion, the complexity of cardiac electrical signals can be used to predict EEG changes after stress.

  10. Seismic signal analysis based on the dual-tree complex wavelet packet transform

    Institute of Scientific and Technical Information of China (English)

    谢周敏; 王恩福; 张国宏; 赵国存; 陈旭庚

    2004-01-01

    We tried to apply the dual-tree complex wavelet packet transform in seismic signal analysis. The complex waveletpacket transform (CWPT) combine the merits of real wavelet packet transform with that of complex continuouswavelet transform (CCWT). It can not only pick up the phase information of signal, but also produce better "focalizing" function if it matches the phase spectrum of signals analyzed. We here described the dual-tree CWPT algorithm, and gave the examples of simulation and actual seismic signals analysis. As shown by our results, thedual-tree CWPT is a very efecfive method in analyzing seismic signals with non-linear phase.

  11. Uncovering brain-heart information through advanced signal and image processing.

    Science.gov (United States)

    Valenza, Gaetano; Toschi, Nicola; Barbieri, Riccardo

    2016-05-13

    Through their dynamical interplay, the brain and the heart ensure fundamental homeostasis and mediate a number of physiological functions as well as their disease-related aberrations. Although a vast number of ad hoc analytical and computational tools have been recently applied to the non-invasive characterization of brain and heart dynamic functioning, little attention has been devoted to combining information to unveil the interactions between these two physiological systems. This theme issue collects contributions from leading experts dealing with the development of advanced analytical and computational tools in the field of biomedical signal and image processing. It includes perspectives on recent advances in 7 T magnetic resonance imaging as well as electroencephalogram, electrocardiogram and cerebrovascular flow processing, with the specific aim of elucidating methods to uncover novel biological and physiological correlates of brain-heart physiology and physiopathology. PMID:27044995

  12. Brain MRI findings of welders : high signal intensity in T1WI secondary to manganese exposure

    International Nuclear Information System (INIS)

    To evaluate the clinical and brain MRI findings of welders and to determine the utility of MRI in the assessment of occupational manganese exposure. All welders complained of fatigue, headache, anorexia, and decreased libido. The palmomental reflex was positive in five (28%), Myerson's sign in four (22%), and intention tremor in three (17%). Mean blood Mn was 5.18 (range, 1.77-9.34) μg/dl, mean urine Mn was 5.84 (range, 1.07 -22) μg/l, serum Fe was elevated in one welder, and serum Cd in two. T1WI of brain MRI revealed high signal intensities in the globus pallidus, the putamen, the substantia nigra, the tectum, the caudate nucleus, the subthalamic nucleus, the hypothalamus and the pituitary gland. These intensities correlated closely with blood Mn levels, suggesting their potential role in estimating the accumulation of Mn in the brain. (author). 25 refs., 2 tabs., 5 figs

  13. Brain MRI findings of welders : high signal intensity in T1WI secondary to manganese exposure

    Energy Technology Data Exchange (ETDEWEB)

    Kim, K. W.; Lim, M. A.; Shon, M. Y.; Lee, S. H.; Ha, D. G.; Kwon, K. R.; Kim, S. S.; Hong, Y. S.; Lee, Y. H. [Sunlin Presbyterian Hospital, Pohang (Korea, Republic of); Cheong, H. K. [Dongguk University, Seoul (Korea, Republic of)

    1998-03-01

    To evaluate the clinical and brain MRI findings of welders and to determine the utility of MRI in the assessment of occupational manganese exposure. All welders complained of fatigue, headache, anorexia, and decreased libido. The palmomental reflex was positive in five (28%), Myerson`s sign in four (22%), and intention tremor in three (17%). Mean blood Mn was 5.18 (range, 1.77-9.34) {mu}g/dl, mean urine Mn was 5.84 (range, 1.07 -22) {mu}g/l, serum Fe was elevated in one welder, and serum Cd in two. T1WI of brain MRI revealed high signal intensities in the globus pallidus, the putamen, the substantia nigra, the tectum, the caudate nucleus, the subthalamic nucleus, the hypothalamus and the pituitary gland. These intensities correlated closely with blood Mn levels, suggesting their potential role in estimating the accumulation of Mn in the brain. (author). 25 refs., 2 tabs., 5 figs.

  14. EEG Signal Denoising and Feature Extraction Using Wavelet Transform in Brain Computer Interface

    Institute of Scientific and Technical Information of China (English)

    WU Ting; YAN Guo-zheng; YANG Bang-hua; SUN Hong

    2007-01-01

    Electroencephalogram (EEG) signal preprocessing is one of the most important techniques in brain computer interface (BCI). The target is to increase signal-to-noise ratio and make it more favorable for feature extraction and pattern recognition. Wavelet transform is a method of multi-resolution time-frequency analysis, it can decompose the mixed signals which consist of different frequencies into different frequency band. EEG signal is analyzed and denoised using wavelet transform. Moreover, wavelet transform can be used for EEG feature extraction. The energies of specific sub-bands and corresponding decomposition coefficients which have maximal separability according to the Fisher distance criterion are selected as features. The eigenvector for classification is obtained by combining the effective features from different channels. The performance is evaluated by separability and pattern recognition accuracy using the data set of BCI 2003 Competition, the final classification results have proved the effectiveness of this technology for EEG denoising and feature extraction.

  15. Sexual differentiation of the brain requires perinatal kisspeptin-GnRH neuron signaling.

    Science.gov (United States)

    Clarkson, Jenny; Busby, Ellen R; Kirilov, Milen; Schütz, Günther; Sherwood, Nancy M; Herbison, Allan E

    2014-11-12

    Sex differences in brain function underlie robust differences between males and females in both normal and disease states. Although alternative mechanisms exist, sexual differentiation of the male mammalian brain is initiated predominantly by testosterone secreted by the testes during the perinatal period. Despite considerable advances in understanding how testosterone and its metabolite estradiol sexually differentiate the brain, little is known about the mechanism that generates the male-specific perinatal testosterone surge. In mice, we show that a male-specific activation of GnRH neurons occurs 0-2 h following birth and that this correlates with the male-specific surge of testosterone occurring up to 5 h after birth. The necessity of GnRH signaling for the sexually differentiating effects of the perinatal testosterone surge was demonstrated by the persistence of female-like brain characteristics in adult male, GnRH receptor knock-out mice. Kisspeptin neurons have recently been identified to be potent, direct activators of GnRH neurons. We demonstrate that a population of kisspeptin neurons appears in the preoptic area of only the male between E19 and P1. The importance of kisspeptin inputs to GnRH neurons for the process of sexual differentiation was demonstrated by the lack of a normal neonatal testosterone surge, and disordered brain sexual differentiation of male mice in which the kisspeptin receptor was deleted selectively from GnRH neurons. These observations demonstrate the necessity of perinatal GnRH signaling for driving brain sexual differentiation and indicate that kisspeptin inputs to GnRH neurons are essential for this process to occur. PMID:25392497

  16. GPCR – G protein complexes – the fundamental signaling assembly

    OpenAIRE

    Jastrzebska, Beata

    2013-01-01

    G protein coupled receptors (GPCR) constitute the largest group of cell surface receptors that transmit various signals across biological membranes through the binding and activation of heterotrimeric G proteins, which amplify the signal and activate downstream effectors leading to the biological responses. Thus, the first critical step in this signaling cascade is the interaction between receptor and its cognate G protein. Understanding this critical event at the molecular level is of high i...

  17. DISC1 regulates astrogenesis in the embryonic brain via modulation of RAS/MEK/ERK signaling through RASSF7.

    Science.gov (United States)

    Wang, Shukun; Liang, Qingli; Qiao, Huimin; Li, Hong; Shen, Tianjin; Ji, Fen; Jiao, Jianwei

    2016-08-01

    Disrupted in schizophrenia 1 (DISC1) is known as a high susceptibility gene for schizophrenia. Recent studies have indicated that schizophrenia might be caused by glia defects and dysfunction. However, there is no direct evidence of a link between the schizophrenia gene DISC1 and gliogenesis defects. Thus, an investigation into the involvement of DISC1 (a ubiquitously expressed brain protein) in astrogenesis during the late stage of mouse embryonic brain development is warranted. Here, we show that suppression of DISC1 expression represses astrogenesis in vitro and in vivo, and that DISC1 overexpression substantially enhances the process. Furthermore, mouse and human DISC1 overexpression rescued the astrogenesis defects caused by DISC1 knockdown. Mechanistically, DISC1 activates the RAS/MEK/ERK signaling pathway via direct association with RASSF7. Also, the pERK complex undergoes nuclear translocation and influences the expression of genes related to astrogenesis. In summary, our results demonstrate that DISC1 regulates astrogenesis by modulating RAS/MEK/ERK signaling via RASSF7 and provide a framework for understanding how DISC1 dysfunction might lead to neuropsychiatric diseases. PMID:27287808

  18. Detecting the Intention to Move Upper Limbs from Electroencephalographic Brain Signals

    Directory of Open Access Journals (Sweden)

    Berenice Gudiño-Mendoza

    2016-01-01

    Full Text Available Early decoding of motor states directly from the brain activity is essential to develop brain-machine interfaces (BMI for natural motor control of neuroprosthetic devices. Hence, this study aimed to investigate the detection of movement information before the actual movement occurs. This information piece could be useful to provide early control signals to drive BMI-based rehabilitation and motor assisted devices, thus providing a natural and active rehabilitation therapy. In this work, electroencephalographic (EEG brain signals from six healthy right-handed participants were recorded during self-initiated reaching movements of the upper limbs. The analysis of these EEG traces showed that significant event-related desynchronization is present before and during the execution of the movements, predominantly in the motor-related α and β frequency bands and in electrodes placed above the motor cortex. This oscillatory brain activity was used to continuously detect the intention to move the limbs, that is, to identify the motor phase prior to the actual execution of the reaching movement. The results showed, first, significant classification between relax and movement intention and, second, significant detection of movement intention prior to the onset of the executed movement. On the basis of these results, detection of movement intention could be used in BMI settings to reduce the gap between mental motor processes and the actual movement performed by an assisted or rehabilitation robotic device.

  19. Immune-to-brain signalling: the role of cerebral CD163-positive macrophages

    OpenAIRE

    Galea, Ian; Felton, Leigh M.; Waters, Sara; van Rooijen, Nico; Perry, V. Hugh; Newman, Tracey A

    2008-01-01

    Systemic inflammation induces cytokine synthesis within the central nervous system. This results in sickness behaviour and may exacerbate ongoing neuroinflammatory disease. The precise mechanisms underlying the relay of signal from the periphery to the central nervous system are not entirely understood. CD163-positive macrophages occupy a unique position at the blood-brain barrier and upregulate prostaglandin-synthesizing enzymes in response to systemic inflammation. This finding suggests tha...

  20. Long-term music training tunes how the brain temporally binds signals from multiple senses

    OpenAIRE

    Lee, Hweeling; Noppeney, Uta

    2011-01-01

    Practicing a musical instrument is a rich multisensory experience involving the integration of visual, auditory, and tactile inputs with motor responses. This combined psychophysics–fMRI study used the musician's brain to investigate how sensory-motor experience molds temporal binding of auditory and visual signals. Behaviorally, musicians exhibited a narrower temporal integration window than nonmusicians for music but not for speech. At the neural level, musicians showed increased audiovisua...

  1. Analysis on Design of Kohonen-network System Based on Classification of Complex Signals

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The key methods of detection and classification of the electroencephalogram(EEG) used in recent years are introduced . Taking EEG for example, the design plan of Kohonen neural network system based on detection and classification of complex signals is proposed, and both the network design and signal processing are analyzed, including pre-processing of signals, extraction of signal features, classification of signal and network topology, etc.

  2. Study on Brain Dynamics by Non Linear Analysis of Music Induced EEG Signals

    Science.gov (United States)

    Banerjee, Archi; Sanyal, Shankha; Patranabis, Anirban; Banerjee, Kaushik; Guhathakurta, Tarit; Sengupta, Ranjan; Ghosh, Dipak; Ghose, Partha

    2016-02-01

    Music has been proven to be a valuable tool for the understanding of human cognition, human emotion, and their underlying brain mechanisms. The objective of this study is to analyze the effect of Hindustani music on brain activity during normal relaxing conditions using electroencephalography (EEG). Ten male healthy subjects without special musical education participated in the study. EEG signals were acquired at the frontal (F3/F4) lobes of the brain while listening to music at three experimental conditions (rest, with music and without music). Frequency analysis was done for the alpha, theta and gamma brain rhythms. The finding shows that arousal based activities were enhanced while listening to Hindustani music of contrasting emotions (romantic/sorrow) for all the subjects in case of alpha frequency bands while no significant changes were observed in gamma and theta frequency ranges. It has been observed that when the music stimulus is removed, arousal activities as evident from alpha brain rhythms remain for some time, showing residual arousal. This is analogous to the conventional 'Hysteresis' loop where the system retains some 'memory' of the former state. This is corroborated in the non linear analysis (Detrended Fluctuation Analysis) of the alpha rhythms as manifested in values of fractal dimension. After an input of music conveying contrast emotions, withdrawal of music shows more retention as evidenced by the values of fractal dimension.

  3. Comparative analysis of brain EEG signals generated from the right and left hand while writing

    Science.gov (United States)

    Sardesai, Neha; Jamali Mahabadi, S. E.; Meng, Qinglei; Choa, Fow-Sen

    2016-05-01

    This paper provides a comparative analysis of right handed people and left handed people when they write with both their hands. Two left handed and one right handed subject were asked to write their respective names on a paper using both, their left and right handed, and their brain signals were measured using EEG. Similarly, they were asked to perform simple mathematical calculations using both their hand. The data collected from the EEG from writing with both hands is compared. It is observed that though it is expected that the right brain only would contribute to left handed writing and vice versa, it is not so. When a right handed person writes with his/her left hand, the initial instinct is to go for writing with the right hand. Hence, both parts of the brain are active when a subject writes with the other hand. However, when the activity is repeated, the brain learns to expect to write with the other hand as the activity is repeated and then only the expected part of the brain is active.

  4. Matched signal detection on graphs: Theory and application to brain imaging data classification.

    Science.gov (United States)

    Hu, Chenhui; Sepulcre, Jorge; Johnson, Keith A; Fakhri, Georges E; Lu, Yue M; Li, Quanzheng

    2016-01-15

    Motivated by recent progress in signal processing on graphs, we have developed a matched signal detection (MSD) theory for signals with intrinsic structures described by weighted graphs. First, we regard graph Laplacian eigenvalues as frequencies of graph-signals and assume that the signal is in a subspace spanned by the first few graph Laplacian eigenvectors associated with lower eigenvalues. The conventional matched subspace detector can be applied to this case. Furthermore, we study signals that may not merely live in a subspace. Concretely, we consider signals with bounded variation on graphs and more general signals that are randomly drawn from a prior distribution. For bounded variation signals, the test is a weighted energy detector. For the random signals, the test statistic is the difference of signal variations on associated graphs, if a degenerate Gaussian distribution specified by the graph Laplacian is adopted. We evaluate the effectiveness of the MSD on graphs both with simulated and real data sets. Specifically, we apply MSD to the brain imaging data classification problem of Alzheimer's disease (AD) based on two independent data sets: 1) positron emission tomography data with Pittsburgh compound-B tracer of 30 AD and 40 normal control (NC) subjects, and 2) resting-state functional magnetic resonance imaging (R-fMRI) data of 30 early mild cognitive impairment and 20 NC subjects. Our results demonstrate that the MSD approach is able to outperform the traditional methods and help detect AD at an early stage, probably due to the success of exploiting the manifold structure of the data. PMID:26481679

  5. Quantifying the complexity of human colonic pressure signals using an entropy measure.

    Science.gov (United States)

    Xu, Fei; Yan, Guozheng; Zhao, Kai; Lu, Li; Wang, Zhiwu; Gao, Jinyang

    2016-02-01

    Studying the complexity of human colonic pressure signals is important in understanding this intricate, evolved, dynamic system. This article presents a method for quantifying the complexity of colonic pressure signals using an entropy measure. As a self-adaptive non-stationary signal analysis algorithm, empirical mode decomposition can decompose a complex pressure signal into a set of intrinsic mode functions (IMFs). Considering that IMF2, IMF3, and IMF4 represent crucial characteristics of colonic motility, a new signal was reconstructed with these three signals. Then, the time entropy (TE), power spectral entropy (PSE), and approximate entropy (AE) of the reconstructed signal were calculated. For subjects with constipation and healthy individuals, experimental results showed that the entropies of reconstructed signals between these two classes were distinguishable. Moreover, the TE, PSE, and AE can be extracted as features for further subject classification. PMID:26043437

  6. [Signaling molecules in the brain and epigenetic factors in neurodegenerative and mental disorders].

    Science.gov (United States)

    Gomazkov, O A

    2015-01-01

    The literature on a role of signaling molecules in the organization of memory and cognitive functions is analyzed basing on mechanisms of memory physiology determined by a complex of biochemical processes initiated by the transmission of the signal to the synapse and completed by the synthesis of functionally significant molecules in the neuronal genetic apparatus. The center of these processes is a coordinated system of signal transduction, transcription, epigenetic and neurotrophic molecules. The dissonance of signal mechanisms is a prime cause of memory impairment and cognitive dysfunction as social maladaptation factors. The results of experimental and clinical studies of a role of the multilevel signaling system in age-related, neurodegenerative (Alzheimer’s disease) and mental (depression) disorders are discussed. At the same time, signaling molecules may be considered as particular targets for new therapeutic approaches. PMID:26649375

  7. Graph theory analysis of complex brain networks: new concepts in brain mapping applied to neurosurgery.

    Science.gov (United States)

    Hart, Michael G; Ypma, Rolf J F; Romero-Garcia, Rafael; Price, Stephen J; Suckling, John

    2016-06-01

    Neuroanatomy has entered a new era, culminating in the search for the connectome, otherwise known as the brain's wiring diagram. While this approach has led to landmark discoveries in neuroscience, potential neurosurgical applications and collaborations have been lagging. In this article, the authors describe the ideas and concepts behind the connectome and its analysis with graph theory. Following this they then describe how to form a connectome using resting state functional MRI data as an example. Next they highlight selected insights into healthy brain function that have been derived from connectome analysis and illustrate how studies into normal development, cognitive function, and the effects of synthetic lesioning can be relevant to neurosurgery. Finally, they provide a précis of early applications of the connectome and related techniques to traumatic brain injury, functional neurosurgery, and neurooncology. PMID:26544769

  8. Signaled drug delivery and transport across the blood-brain barrier.

    Science.gov (United States)

    Hinow, Peter; Radunskaya, Ami; Mackay, Sean M; Reynolds, John N J; Schroeder, Morgan; Tan, Eng Wui; Tucker, Ian G

    2016-09-01

    We use a mathematical model to describe the delivery of a drug to a specific region of the brain. The drug is carried by liposomes that can release their cargo by application of focused ultrasound (US). Thereupon, the drug is absorbed through the endothelial cells that line the brain capillaries and form the physiologically important blood-brain barrier (BBB). We present a compartmental model of a capillary that is able to capture the complex binding and transport processes the drug undergoes in the blood plasma and at the BBB. We apply this model to the delivery of levodopa (L-dopa, used to treat Parkinson's disease) and doxorubicin (an anticancer agent). The goal is to optimize the delivery of drug while at the same time minimizing possible side effects of the US. PMID:26572864

  9. Cytokinin signal transduction: Known simplicity and unknown complexity

    Institute of Scientific and Technical Information of China (English)

    ZHENG Binglian; SUN Jiaqiang; ZHANG Suzhi; DENG Yan; ZUO Jianru

    2003-01-01

    Cytokinin plays a critical role in plant growth and development by regulating cell divisions and cell differentiation. Recent studies suggest that cytokinin signaling is presumably mediated by a two-component system analogous to those found in bacteria and fungi, which transduces an external signal via a phosphorelay from the plasma membrane-anchored receptors to downstream effectors andregulators. Moreover, cytokinin signaling is highly interactive with other pathways, and many components of the pathway appear to be functionally redundant. Proper address of these questions will be crucial for our further understanding onthis important network.

  10. Correlations between the signal complexity of cerebral and cardiac electrical activity: a multiscale entropy analysis.

    Directory of Open Access Journals (Sweden)

    Pei-Feng Lin

    Full Text Available The heart begins to beat before the brain is formed. Whether conventional hierarchical central commands sent by the brain to the heart alone explain all the interplay between these two organs should be reconsidered. Here, we demonstrate correlations between the signal complexity of brain and cardiac activity. Eighty-seven geriatric outpatients with healthy hearts and varied cognitive abilities each provided a 24-hour electrocardiography (ECG and a 19-channel eye-closed routine electroencephalography (EEG. Multiscale entropy (MSE analysis was applied to three epochs (resting-awake state, photic stimulation of fast frequencies (fast-PS, and photic stimulation of slow frequencies (slow-PS of EEG in the 1-58 Hz frequency range, and three RR interval (RRI time series (awake-state, sleep and that concomitant with the EEG for each subject. The low-to-high frequency power (LF/HF ratio of RRI was calculated to represent sympatho-vagal balance. With statistics after Bonferroni corrections, we found that: (a the summed MSE value on coarse scales of the awake RRI (scales 11-20, RRI-MSE-coarse were inversely correlated with the summed MSE value on coarse scales of the resting-awake EEG (scales 6-20, EEG-MSE-coarse at Fp2, C4, T6 and T4; (b the awake RRI-MSE-coarse was inversely correlated with the fast-PS EEG-MSE-coarse at O1, O2 and C4; (c the sleep RRI-MSE-coarse was inversely correlated with the slow-PS EEG-MSE-coarse at Fp2; (d the RRI-MSE-coarse and LF/HF ratio of the awake RRI were correlated positively to each other; (e the EEG-MSE-coarse at F8 was proportional to the cognitive test score; (f the results conform to the cholinergic hypothesis which states that cognitive impairment causes reduction in vagal cardiac modulation; (g fast-PS significantly lowered the EEG-MSE-coarse globally. Whether these heart-brain correlations could be fully explained by the central autonomic network is unknown and needs further exploration.

  11. Correlations between the signal complexity of cerebral and cardiac electrical activity: a multiscale entropy analysis.

    Science.gov (United States)

    Lin, Pei-Feng; Lo, Men-Tzung; Tsao, Jenho; Chang, Yi-Chung; Lin, Chen; Ho, Yi-Lwun

    2014-01-01

    The heart begins to beat before the brain is formed. Whether conventional hierarchical central commands sent by the brain to the heart alone explain all the interplay between these two organs should be reconsidered. Here, we demonstrate correlations between the signal complexity of brain and cardiac activity. Eighty-seven geriatric outpatients with healthy hearts and varied cognitive abilities each provided a 24-hour electrocardiography (ECG) and a 19-channel eye-closed routine electroencephalography (EEG). Multiscale entropy (MSE) analysis was applied to three epochs (resting-awake state, photic stimulation of fast frequencies (fast-PS), and photic stimulation of slow frequencies (slow-PS)) of EEG in the 1-58 Hz frequency range, and three RR interval (RRI) time series (awake-state, sleep and that concomitant with the EEG) for each subject. The low-to-high frequency power (LF/HF) ratio of RRI was calculated to represent sympatho-vagal balance. With statistics after Bonferroni corrections, we found that: (a) the summed MSE value on coarse scales of the awake RRI (scales 11-20, RRI-MSE-coarse) were inversely correlated with the summed MSE value on coarse scales of the resting-awake EEG (scales 6-20, EEG-MSE-coarse) at Fp2, C4, T6 and T4; (b) the awake RRI-MSE-coarse was inversely correlated with the fast-PS EEG-MSE-coarse at O1, O2 and C4; (c) the sleep RRI-MSE-coarse was inversely correlated with the slow-PS EEG-MSE-coarse at Fp2; (d) the RRI-MSE-coarse and LF/HF ratio of the awake RRI were correlated positively to each other; (e) the EEG-MSE-coarse at F8 was proportional to the cognitive test score; (f) the results conform to the cholinergic hypothesis which states that cognitive impairment causes reduction in vagal cardiac modulation; (g) fast-PS significantly lowered the EEG-MSE-coarse globally. Whether these heart-brain correlations could be fully explained by the central autonomic network is unknown and needs further exploration. PMID:24498375

  12. Predict or classify: The deceptive role of time-locking in brain signal classification

    Science.gov (United States)

    Rusconi, Marco; Valleriani, Angelo

    2016-01-01

    Several experimental studies claim to be able to predict the outcome of simple decisions from brain signals measured before subjects are aware of their decision. Often, these studies use multivariate pattern recognition methods with the underlying assumption that the ability to classify the brain signal is equivalent to predict the decision itself. Here we show instead that it is possible to correctly classify a signal even if it does not contain any predictive information about the decision. We first define a simple stochastic model that mimics the random decision process between two equivalent alternatives, and generate a large number of independent trials that contain no choice-predictive information. The trials are first time-locked to the time point of the final event and then classified using standard machine-learning techniques. The resulting classification accuracy is above chance level long before the time point of time-locking. We then analyze the same trials using information theory. We demonstrate that the high classification accuracy is a consequence of time-locking and that its time behavior is simply related to the large relaxation time of the process. We conclude that when time-locking is a crucial step in the analysis of neural activity patterns, both the emergence and the timing of the classification accuracy are affected by structural properties of the network that generates the signal. PMID:27320688

  13. Protein complex analysis of native brain potassium channels by proteomics.

    Science.gov (United States)

    Sandoz, Guillaume; Lesage, Florian

    2008-01-01

    TREK potassium channels belong to a family of channel subunits with two-pore domains (K(2P)). TREK1 knockout mice display impaired polyunsaturated fatty acid-mediated protection against brain ischemia, reduced sensitivity to volatile anesthetics, resistance to depression and altered perception of pain. Recently, we isolated native TREK1 channels from mouse brain and identified their specific components by mass spectrometry. Among the identified partners, the A-Kinase Anchoring Protein AKAP150 binds to a regulatory domain of TREK1 and acts as a molecular switch. It transforms low activity, outwardly rectifying TREK1 currents into robust leak conductances resistant to stimulation by arachidonic acid, membrane stretch and acidification. Inhibition of the TREK1/AKAP150 channel by Gs-coupled receptors is as extensive as for TREK1 alone (but faster) whereas inhibition of TREK1/AKAP150 by Gq-coupled receptors is reduced. Furthermore, the association of AKAP150 with TREK1 channels integrates them into postsynaptic scaffolds where G protein-coupled membrane receptors and channels dock simultaneously. This chapter describes the proteomic approach used to study the composition of native TREK1 channels and point out its advantages and limitations over more classical methods (two-hybrid screenings in the yeast and bacteria or GST-pull down). PMID:18998088

  14. SIMULATING BIOCHEMICAL SIGNALING NETWORKS IN COMPLEX MOVING GEOMETRIES.

    Science.gov (United States)

    Strychalski, Wanda; Adalsteinsson, David; Elston, Timothy C

    2010-01-01

    Signaling networks regulate cellular responses to environmental stimuli through cascades of protein interactions. External signals can trigger cells to polarize and move in a specific direction. During migration, spatially localized activity of proteins is maintained. To investigate the effects of morphological changes on intracellular signaling, we developed a numerical scheme consisting of a cut cell finite volume spatial discretization coupled with level set methods to simulate the resulting advection-reaction-diffusion system. We then apply the method to several biochemical reaction networks in changing geometries. We found that a Turing instability can develop exclusively by cell deformations that maintain constant area. For a Turing system with a geometry-dependent single or double peak solution, simulations in a dynamically changing geometry suggest that a single peak solution is the only stable one, independent of the oscillation frequency. The method is also applied to a model of a signaling network in a migrating fibroblast. PMID:24086102

  15. Effects of Cell Phone Radiofrequency Signal Exposure on Brain Glucos Metabolism

    International Nuclear Information System (INIS)

    The dramatic increase in use of cellular telephones has generated concern about possible negative effects of radiofrequency signals delivered to the brain. However, whether acute cell phone exposure affects the human brain is unclear. To evaluate if acute cell phone exposure affects brain glucose metabolism, a marker of brain activity. Randomized crossover study conducted between January 1 and December 31, 2009, at a single US laboratory among 47 healthy participants recruited from the community. Cell phones were placed on the left and right ears and positron emission tomography with (18F)fluorodeoxyglucose injection was used to measure brain glucose metabolism twice, once with the right cell phone activated (sound muted) for 50 minutes ('on' condition) and once with both cell phones deactivated ('off' condition). Statistical parametric mapping was used to compare metabolism between on and off conditions using paired t tests, and Pearson linear correlations were used to verify the association of metabolism and estimated amplitude of radiofrequency-modulated electromagnetic waves emitted by the cell phone. Clusters with at least 1000 voxels (volume >8 cm3) and P < .05 (corrected for multiple comparisons) were considered significant. Brain glucose metabolism computed as absolute metabolism ((micro)mol/100 g per minute) and as normalized metabolism (region/whole brain). Whole-brain metabolism did not differ between on and off conditions. In contrast, metabolism in the region closest to the antenna (orbitofrontal cortex and temporal pole) was significantly higher for on than off conditions (35.7 vs 33.3 (micro)mol/100 g per minute; mean difference, 2.4 (95% confidence interval, 0.67-4.2); P = .004). The increases were significantly correlated with the estimated electromagnetic field amplitudes both for absolute metabolism (R = 0.95, P < .001) and normalized metabolism (R = 0.89; P < .001). In healthy participants and compared with no exposure, 50-minute cell phone

  16. HBpF-proBDNF: A New Tool for the Analysis of Pro-Brain Derived Neurotrophic Factor Receptor Signaling and Cell Biology.

    Science.gov (United States)

    Gaub, Perrine; de Léon, Andrès; Gibon, Julien; Soubannier, Vincent; Dorval, Geneviève; Séguéla, Philippe; Barker, Philip A

    2016-01-01

    Neurotrophins activate intracellular signaling pathways necessary for neuronal survival, growth and apoptosis. The most abundant neurotrophin in the adult brain, brain-derived neurotrophic factor (BDNF), is first synthesized as a proBDNF precursor and recent studies have demonstrated that proBDNF can be secreted and that it functions as a ligand for a receptor complex containing p75NTR and sortilin. Activation of proBDNF receptors mediates growth cone collapse, reduces synaptic activity, and facilitates developmental apoptosis of motoneurons but the precise signaling cascades have been difficult to discern. To address this, we have engineered, expressed and purified HBpF-proBDNF, an expression construct containing a 6X-HIS tag, a biotin acceptor peptide (BAP) sequence, a PreScission™ Protease cleavage site and a FLAG-tag attached to the N-terminal part of murine proBDNF. Intact HBpF-proBDNF has activities indistinguishable from its wild-type counterpart and can be used to purify proBDNF signaling complexes or to monitor proBDNF endocytosis and retrograde transport. HBpF-proBDNF will be useful for characterizing proBDNF signaling complexes and for deciphering the role of proBDNF in neuronal development, synapse function and neurodegenerative disease. PMID:26950209

  17. Signalling through the type 1 insulin-like growth factor receptor (IGF1R interacts with canonical Wnt signalling to promote neural proliferation in developing brain

    Directory of Open Access Journals (Sweden)

    Qichen Hu

    2012-07-01

    Full Text Available Signalling through the IGF1R [type 1 IGF (insulin-like growth factor receptor] and canonical Wnt signalling are two signalling pathways that play critical roles in regulating neural cell generation and growth. To determine whether the signalling through the IGF1R can interact with the canonical Wnt signalling pathway in neural cells in vivo, we studied mutant mice with altered IGF signalling. We found that in mice with blunted IGF1R expression specifically in nestin-expressing neural cells (IGF1RNestin−KO mice the abundance of neural β-catenin was significantly reduced. Blunting IGF1R expression also markedly decreased: (i the activity of a LacZ (β-galactosidase reporter transgene that responds to Wnt nuclear signalling (LacZTCF reporter transgene and (ii the number of proliferating neural precursors. In contrast, overexpressing IGF-I (insulin-like growth factor I in brain markedly increased the activity of the LacZTCF reporter transgene. Consistently, IGF-I treatment also markedly increased the activity of the LacZTCF reporter transgene in embryonic neuron cultures that are derived from LacZTCF Tg (transgenic mice. Importantly, increasing the abundance of β-catenin in IGF1RNestin−KO embryonic brains by suppressing the activity of GSK3β (glycogen synthase kinase-3β significantly alleviated the phenotypic changes induced by IGF1R deficiency. These phenotypic changes includes: (i retarded brain growth, (ii reduced precursor proliferation and (iii decreased neuronal number. Our current data, consistent with our previous study of cultured oligodendrocytes, strongly support the concept that IGF signalling interacts with canonical Wnt signalling in the developing brain to promote neural proliferation. The interaction of IGF and canonical Wnt signalling plays an important role in normal brain development by promoting neural precursor proliferation.

  18. Histone deacetylases control neurogenesis in embryonic brain by inhibition of BMP2/4 signaling.

    Directory of Open Access Journals (Sweden)

    Maya Shakèd

    Full Text Available BACKGROUND: Histone-modifying enzymes are essential for a wide variety of cellular processes dependent upon changes in gene expression. Histone deacetylases (HDACs lead to the compaction of chromatin and subsequent silencing of gene transcription, and they have recently been implicated in a diversity of functions and dysfunctions in the postnatal and adult brain including ocular dominance plasticity, memory consolidation, drug addiction, and depression. Here we investigate the role of HDACs in the generation of neurons and astrocytes in the embryonic brain. PRINCIPAL FINDINGS: As a variety of HDACs are expressed in differentiating neural progenitor cells, we have taken a pharmacological approach to inhibit multiple family members. Inhibition of class I and II HDACs in developing mouse embryos with trichostatin A resulted in a dramatic reduction in neurogenesis in the ganglionic eminences and a modest increase in neurogenesis in the cortex. An identical effect was observed upon pharmacological inhibition of HDACs in in vitro-differentiating neural precursors derived from the same brain regions. A reduction in neurogenesis in ganglionic eminence-derived neural precursors was accompanied by an increase in the production of immature astrocytes. We show that HDACs control neurogenesis by inhibition of the bone morphogenetic protein BMP2/4 signaling pathway in radial glial cells. HDACs function at the transcriptional level by inhibiting and promoting, respectively, the expression of Bmp2 and Smad7, an intracellular inhibitor of BMP signaling. Inhibition of the BMP2/4 signaling pathway restored normal levels of neurogenesis and astrogliogenesis to both ganglionic eminence- and cortex-derived cultures in which HDACs were inhibited. CONCLUSIONS: Our results demonstrate a transcriptionally-based regulation of BMP2/4 signaling by HDACs both in vivo and in vitro that is critical for neurogenesis in the ganglionic eminences and that modulates cortical

  19. Complex Dynamics in Physiological Systems: From Heart to Brain

    CERN Document Server

    Dana, Syamal K; Kurths, Jürgen

    2009-01-01

    Nonlinear dynamics has become an important field of research in recent years in many areas of the natural sciences. In particular, it has potential applications in biology and medicine; nonlinear data analysis has helped to detect the progress of cardiac disease, physiological disorders, for example episodes of epilepsy, and others. This book focuses on the current trends of research concerning the prediction of sudden cardiac death and the onset of epileptic seizures, using the nonlinear analysis based on ECG and EEG data. Topics covered include the analysis of cardiac models and neural models. The book is a collection of recent research papers by leading physicists, mathematicians, cardiologists and neurobiologists who are actively involved in using the concepts of nonlinear dynamics to explore the functional behaviours of heart and brain under normal and pathological conditions. This collection is intended for students in physics, mathematics and medical sciences, and researchers in interdisciplinary areas...

  20. Expression Profile of DNA Damage Signaling Genes in Proton Exposed Mouse Brain

    Science.gov (United States)

    Ramesh, Govindarajan; Wu, Honglu

    Exposure of living systems to radiation results in a wide assortment of lesions, the most signif-icant of is damage to genomic DNA which induce several cellular functions such as cell cycle arrest, repair, apoptosis etc. The radiation induced DNA damage investigation is one of the im-portant area in biology, but still the information available regarding the effects of proton is very limited. In this report, we investigated the differential gene expression pattern of DNA damage signaling genes particularly, damaged DNA binding, repair, cell cycle arrest, checkpoints and apoptosis using quantitative real-time RT-PCR array in proton exposed mouse brain tissues. The expression profiles showed significant changes in DNA damage related genes in 2Gy proton exposed mouse brain tissues as compared with control brain tissues. Furthermore, we also show that significantly increased levels of apoptotic related genes, caspase-3 and 8 activities in these cells, suggesting that in addition to differential expression of DNA damage genes, the alteration of apoptosis related genes may also contribute to the radiation induced DNA damage followed by programmed cell death. In summary, our findings suggest that proton exposed brain tissue undergo severe DNA damage which in turn destabilize the chromatin stability.

  1. SELF-ADAPTIVE CONTROLS OF A COMPLEX CELLULAR SIGNALING TRANSDUCTION SYSTEM

    Institute of Scientific and Technical Information of China (English)

    LI Hong; ZHOU Zhiyuan; DAI Rongyang; LUO Bo; ZHENG Xiaoli; YANG Wenli; HE Tao; WU Minglu

    2004-01-01

    In cells, the interactions of distinct signaling transduction pathways originating from cross-talkings between signaling molecules give rise to the formation of signaling transduction networks, which contributes to the changes (emergency) of kinetic behaviors of signaling system compared with single molecule or pathway. Depending on the known experimental data, we have constructed a model for complex cellular signaling transduction system, which is derived from signaling transduction of epidermal growth factor receptor in neuron. By the computational simulating methods, the self-adaptive controls of this system have been investigated. We find that this model exhibits a relatively stable selfadaptive system, especially to over-stimulation of agonist, and the amplitude and duration of signaling intermediates in it could be controlled by multiple self-adaptive effects, such as "signal scattering", "positive feedback", "negative feedback" and "B-Raf shunt". Our results provide an approach to understanding the dynamic behaviors of complex biological systems.

  2. Signal transduction by the major histocompatibility complex class I molecule

    DEFF Research Database (Denmark)

    Pedersen, Anders Elm; Skov, S; Bregenholt, S; Ruhwald, M; Claesson, M H

    1999-01-01

    Ligation of cell surface major histocompatibility class I (MHC-I) proteins by antibodies, or by their native counter receptor, the CD8 molecule, mediates transduction of signals into the cells. MHC-I-mediated signaling can lead to both increased and decreased activity of the MHC-I-expressing cell...... immediately after and at later intervals following MHC-I ligation. It is hypothesized that MHC-I expression, both ontogenically and in evolution, is driven by a cell-mediated selection pressure advantageous to the MHC-I-expressing cell. Accordingly, in addition to their role in T-cell selection and...

  3. Brain

    Science.gov (United States)

    ... will return after updating. Resources Archived Modules Updates Brain Cerebrum The cerebrum is the part of the ... the outside of the brain and spinal cord. Brain Stem The brain stem is the part of ...

  4. A guide to delineate the logic of neurovascular signaling in the brain

    Directory of Open Access Journals (Sweden)

    David eKleinfeld

    2011-04-01

    Full Text Available The neurovascular system may be viewed as a distributed nervous system within the brain. It transforms local neuronal activity into a change in the tone of smooth muscle that lines the walls of arterioles and microvessels. We review the current state of neurovascular coupling, with an emphasis on signaling molecules that convey information from neurons to neighboring vessels. At the level of neocortex, this coupling is mediated by: (i a likely direct interaction with inhibitory neurons, (ii indirect interaction, via astrocytes, with excitatory neurons, and (iii fiber tracts from subcortical layers. Substantial evidence shows that control involves competition between signals that promote vasoconstriction versus vasodilation. Consistent with this picture is evidence that, under certain circumstances, increased neuronal activity can lead to vasoconstriction rather than vasodilation. This confounds naïve interpretations of functional brain images. We discuss experimental approaches to detect signaling molecules in vivo with the goal of formulating an empirical basis for the observed logic of neurovascular control.

  5. The Two Channels Complex Bioimpedance Signals in Cardiology

    Czech Academy of Sciences Publication Activity Database

    Halámek, Josef; Vondra, Vlastimil; Jurák, Pavel; Verner, Petr

    Brno: University of Technology, 2006, s. 137-139. ISBN 80-214-3152-0. ISSN 1211-412X. [BIOSIGNAL 2006 /18./. Brno (CZ), 28.06.2006-30.06.2006] R&D Projects: GA ČR GA102/06/0136 Institutional research plan: CEZ:AV0Z20650511 Keywords : bioimpedance * compex signal Subject RIV: FS - Medical Facilities ; Equipment

  6. Nonlinear signal processing for ultrasonic imaging of material complexity

    Czech Academy of Sciences Publication Activity Database

    Dos Santos, S.; Vejvodová, Šárka; Převorovský, Zdeněk

    2010-01-01

    Roč. 59, č. 2 (2010), s. 108-117. ISSN 1736-6046 Institutional research plan: CEZ:AV0Z20760514 Keywords : nonlinear signal processing * TR-NEWS * symmetry analysis * DORT Subject RIV: BI - Acoustics Impact factor: 0.464, year: 2010 www.eap.ee/proceedings

  7. Astrocyte sodium signaling and neuro-metabolic coupling in the brain.

    Science.gov (United States)

    Rose, C R; Chatton, J-Y

    2016-05-26

    At tripartite synapses, astrocytes undergo calcium signaling in response to release of neurotransmitters and this calcium signaling has been proposed to play a critical role in neuron-glia interaction. Recent work has now firmly established that, in addition, neuronal activity also evokes sodium transients in astrocytes, which can be local or global depending on the number of activated synapses and the duration of activity. Furthermore, astrocyte sodium signals can be transmitted to adjacent cells through gap junctions and following release of gliotransmitters. A main pathway for activity-related sodium influx into astrocytes is via high-affinity sodium-dependent glutamate transporters. Astrocyte sodium signals differ in many respects from the well-described glial calcium signals both in terms of their temporal as well as spatial distribution. There are no known buffering systems for sodium ions, nor is there store-mediated release of sodium. Sodium signals thus seem to represent rather direct and unbiased indicators of the site and strength of neuronal inputs. As such they have an immediate influence on the activity of sodium-dependent transporters which may even reverse in response to sodium signaling, as has been shown for GABA transporters for example. Furthermore, recovery from sodium transients through Na(+)/K(+)-ATPase requires a measurable amount of ATP, resulting in an activation of glial metabolism. In this review, we present basic principles of sodium regulation and the current state of knowledge concerning the occurrence and properties of activity-related sodium transients in astrocytes. We then discuss different aspects of the relationship between sodium changes in astrocytes and neuro-metabolic coupling, putting forward the idea that indeed sodium might serve as a new type of intracellular ion signal playing an important role in neuron-glia interaction and neuro-metabolic coupling in the healthy and diseased brain. PMID:25791228

  8. Hand posture classification using electrocorticography signals in the gamma band over human sensorimotor brain areas

    Science.gov (United States)

    Chestek, Cynthia A.; Gilja, Vikash; Blabe, Christine H.; Foster, Brett L.; Shenoy, Krishna V.; Parvizi, Josef; Henderson, Jaimie M.

    2013-04-01

    Objective. Brain-machine interface systems translate recorded neural signals into command signals for assistive technology. In individuals with upper limb amputation or cervical spinal cord injury, the restoration of a useful hand grasp could significantly improve daily function. We sought to determine if electrocorticographic (ECoG) signals contain sufficient information to select among multiple hand postures for a prosthetic hand, orthotic, or functional electrical stimulation system.Approach. We recorded ECoG signals from subdural macro- and microelectrodes implanted in motor areas of three participants who were undergoing inpatient monitoring for diagnosis and treatment of intractable epilepsy. Participants performed five distinct isometric hand postures, as well as four distinct finger movements. Several control experiments were attempted in order to remove sensory information from the classification results. Online experiments were performed with two participants. Main results. Classification rates were 68%, 84% and 81% for correct identification of 5 isometric hand postures offline. Using 3 potential controls for removing sensory signals, error rates were approximately doubled on average (2.1×). A similar increase in errors (2.6×) was noted when the participant was asked to make simultaneous wrist movements along with the hand postures. In online experiments, fist versus rest was successfully classified on 97% of trials; the classification output drove a prosthetic hand. Online classification performance for a larger number of hand postures remained above chance, but substantially below offline performance. In addition, the long integration windows used would preclude the use of decoded signals for control of a BCI system. Significance. These results suggest that ECoG is a plausible source of command signals for prosthetic grasp selection. Overall, avenues remain for improvement through better electrode designs and placement, better participant training

  9. Neurosensory Symptom Complexes after Acute Mild Traumatic Brain Injury.

    Directory of Open Access Journals (Sweden)

    Michael E Hoffer

    Full Text Available Mild Traumatic Brain Injury (mTBI is a prominent public health issue. To date, subjective symptom complaints primarily dictate diagnostic and treatment approaches. As such, the description and qualification of these symptoms in the mTBI patient population is of great value. This manuscript describes the symptoms of mTBI patients as compared to controls in a larger study designed to examine the use of vestibular testing to diagnose mTBI. Five symptom clusters were identified: Post-Traumatic Headache/Migraine, Nausea, Emotional/Affective, Fatigue/Malaise, and Dizziness/Mild Cognitive Impairment. Our analysis indicates that individuals with mTBI have headache, dizziness, and cognitive dysfunction far out of proportion to those without mTBI. In addition, sleep disorders and emotional issues were significantly more common amongst mTBI patients than non-injured individuals. A simple set of questions inquiring about dizziness, headache, and cognitive issues may provide diagnostic accuracy. The consideration of other symptoms may be critical for providing prognostic value and treatment for best short-term outcomes or prevention of long-term complications.

  10. Neurosensory Symptom Complexes after Acute Mild Traumatic Brain Injury.

    Science.gov (United States)

    Hoffer, Michael E; Szczupak, Mikhaylo; Kiderman, Alexander; Crawford, James; Murphy, Sara; Marshall, Kathryn; Pelusso, Constanza; Balaban, Carey

    2016-01-01

    Mild Traumatic Brain Injury (mTBI) is a prominent public health issue. To date, subjective symptom complaints primarily dictate diagnostic and treatment approaches. As such, the description and qualification of these symptoms in the mTBI patient population is of great value. This manuscript describes the symptoms of mTBI patients as compared to controls in a larger study designed to examine the use of vestibular testing to diagnose mTBI. Five symptom clusters were identified: Post-Traumatic Headache/Migraine, Nausea, Emotional/Affective, Fatigue/Malaise, and Dizziness/Mild Cognitive Impairment. Our analysis indicates that individuals with mTBI have headache, dizziness, and cognitive dysfunction far out of proportion to those without mTBI. In addition, sleep disorders and emotional issues were significantly more common amongst mTBI patients than non-injured individuals. A simple set of questions inquiring about dizziness, headache, and cognitive issues may provide diagnostic accuracy. The consideration of other symptoms may be critical for providing prognostic value and treatment for best short-term outcomes or prevention of long-term complications. PMID:26727256

  11. Complexity in relational processing predicts changes in functional brain network dynamics.

    Science.gov (United States)

    Cocchi, Luca; Halford, Graeme S; Zalesky, Andrew; Harding, Ian H; Ramm, Brentyn J; Cutmore, Tim; Shum, David H K; Mattingley, Jason B

    2014-09-01

    The ability to link variables is critical to many high-order cognitive functions, including reasoning. It has been proposed that limits in relating variables depend critically on relational complexity, defined formally as the number of variables to be related in solving a problem. In humans, the prefrontal cortex is known to be important for reasoning, but recent studies have suggested that such processes are likely to involve widespread functional brain networks. To test this hypothesis, we used functional magnetic resonance imaging and a classic measure of deductive reasoning to examine changes in brain networks as a function of relational complexity. As expected, behavioral performance declined as the number of variables to be related increased. Likewise, increments in relational complexity were associated with proportional enhancements in brain activity and task-based connectivity within and between 2 cognitive control networks: A cingulo-opercular network for maintaining task set, and a fronto-parietal network for implementing trial-by-trial control. Changes in effective connectivity as a function of increased relational complexity suggested a key role for the left dorsolateral prefrontal cortex in integrating and implementing task set in a trial-by-trial manner. Our findings show that limits in relational processing are manifested in the brain as complexity-dependent modulations of large-scale networks. PMID:23563963

  12. Differential susceptibility of mitochondrial complex II to inhibition by oxaloacetate in brain and heart

    OpenAIRE

    STEPANOVA, Anna; Shurubor, Yevgeniya; Valsecchi, Federica; Galkin, Alexander

    2016-01-01

    Mitochondrial Complex II is a key mitochondrial enzyme connecting the tricarboxylic acid (TCA) cycle and the electron transport chain. Studies of complex II are clinically important since new roles for this enzyme have recently emerged in cell signalling, cancer biology, immune response and neurodegeneration. Oxaloacetate (OAA) is an intermediate of the TCA cycle and at the same time is an inhibitor of complex II with high affinity (Kd ~ 10− 8 M). Whether or not OAA inhibition of complex II i...

  13. Nitric oxide and fever: immune-to-brain signaling vs. thermogenesis in chicks.

    Science.gov (United States)

    Dantonio, Valter; Batalhão, Marcelo E; Fernandes, Marcia H M R; Komegae, Evilin N; Buqui, Gabriela A; Lopes, Norberto P; Gargaglioni, Luciane H; Carnio, Évelin C; Steiner, Alexandre A; Bícego, Kênia C

    2016-05-15

    Nitric oxide (NO) plays a role in thermogenesis but does not mediate immune-to-brain febrigenic signaling in rats. There are suggestions of a different situation in birds, but the underlying evidence is not compelling. The present study was designed to clarify this matter in 5-day-old chicks challenged with a low or high dose of bacterial LPS. The lower LPS dose (2 μg/kg im) induced fever at 3-5 h postinjection, whereas 100 μg/kg im decreased core body temperature (Tc) (at 1 h) followed by fever (at 4 or 5 h). Plasma nitrate levels increased 4 h after LPS injection, but they were not correlated with the magnitude of fever. The NO synthase inhibitor (N(G)-nitro-l-arginine methyl ester, l-NAME; 50 mg/kg im) attenuated the fever induced by either dose of LPS and enhanced the magnitude of the Tc reduction induced by the high dose in chicks at 31-32°C. These effects were associated with suppression of metabolic rate, at least in the case of the high LPS dose. Conversely, the effects of l-NAME on Tc disappeared in chicks maintained at 35-36°C, suggesting that febrigenic signaling was essentially unaffected. Accordingly, the LPS-induced rise in the brain level of PGE2 was not affected by l-NAME. Moreover, l-NAME augmented LPS-induced huddling, which is indicative of compensatory mechanisms to run fever in the face of attenuated thermogenesis. Therefore, as in rats, systemic inhibition of NO synthesis attenuates LPS-induced fever in chicks by affecting thermoeffector activity and not by interfering with immune-to-brain signaling. This may constitute a conserved effect of NO in endotherms. PMID:26984892

  14. Perception of acoustically complex phonological features in vowels is reflected in the induced brain-magnetic activity

    Directory of Open Access Journals (Sweden)

    Obleser Jonas

    2007-06-01

    Full Text Available Abstract A central issue in speech recognition is which basic units of speech are extracted by the auditory system and used for lexical access. One suggestion is that complex acoustic-phonetic information is mapped onto abstract phonological representations of speech and that a finite set of phonological features is used to guide speech perception. Previous studies analyzing the N1m component of the auditory evoked field have shown that this holds for the acoustically simple feature place of articulation. Brain magnetic correlates indexing the extraction of acoustically more complex features, such as lip rounding (ROUND in vowels, have not been unraveled yet. The present study uses magnetoencephalography (MEG to describe the spatial-temporal neural dynamics underlying the extraction of phonological features. We examined the induced electromagnetic brain response to German vowels and found the event-related desynchronization in the upper beta-band to be prolonged for those vowels that exhibit the lip rounding feature (ROUND. It was the presence of that feature rather than circumscribed single acoustic parameters, such as their formant frequencies, which explained the differences between the experimental conditions. We conclude that the prolonged event-related desynchronization in the upper beta-band correlates with the computational effort for the extraction of acoustically complex phonological features from the speech signal. The results provide an additional biomagnetic parameter to study mechanisms of speech perception.

  15. [Music-Acoustic Signals Controlled by Subject's Brain Potentials in the Correction of Unfavorable Functional States].

    Science.gov (United States)

    Fedotchev, A I; Bondar, A T; Bakhchina, A V; Parin, S B; Polevaya, S A; Radchenko, G S

    2016-01-01

    Literature review and the results of own studies on the development and experimental testing of musical EEG neurofeedback technology are presented. The technology is based on exposure of subjects to music or music-like signals that are organized in strict accordance with the current values of brain potentials of the patient. The main attention is paid to the analysis of the effectiveness of several versions of the technology, using specific and meaningful for the individual narrow-frequency EEG oscillators during the correction of unfavorable changes of the functional state. PMID:27149824

  16. Evidence from cyclostomes for complex regionalization of the ancestral vertebrate brain.

    Science.gov (United States)

    Sugahara, Fumiaki; Pascual-Anaya, Juan; Oisi, Yasuhiro; Kuraku, Shigehiro; Aota, Shin-ichi; Adachi, Noritaka; Takagi, Wataru; Hirai, Tamami; Sato, Noboru; Murakami, Yasunori; Kuratani, Shigeru

    2016-03-01

    The vertebrate brain is highly complex, but its evolutionary origin remains elusive. Because of the absence of certain developmental domains generally marked by the expression of regulatory genes, the embryonic brain of the lamprey, a jawless vertebrate, had been regarded as representing a less complex, ancestral state of the vertebrate brain. Specifically, the absence of a Hedgehog- and Nkx2.1-positive domain in the lamprey subpallium was thought to be similar to mouse mutants in which the suppression of Nkx2-1 leads to a loss of the medial ganglionic eminence. Here we show that the brain of the inshore hagfish (Eptatretus burgeri), another cyclostome group, develops domains equivalent to the medial ganglionic eminence and rhombic lip, resembling the gnathostome brain. Moreover, further investigation of lamprey larvae revealed that these domains are also present, ruling out the possibility of convergent evolution between hagfish and gnathostomes. Thus, brain regionalization as seen in crown gnathostomes is not an evolutionary innovation of this group, but dates back to the latest vertebrate ancestor before the divergence of cyclostomes and gnathostomes more than 500 million years ago. PMID:26878236

  17. Mapping Complex Networks: Exploring Boolean Modeling of Signal Transduction Pathways

    OpenAIRE

    Bhardwaj, Gaurav; Wells, Christine P.; Albert, Reka; van Rossum, Damian B.; Patterson, Randen L

    2009-01-01

    In this study, we explored the utility of a descriptive and predictive bionetwork model for phospholipase C-coupled calcium signaling pathways, built with non-kinetic experimental information. Boolean models generated from these data yield oscillatory activity patterns for both the endoplasmic reticulum resident inositol-1,4,5-trisphosphate receptor (IP3R) and the plasma-membrane resident canonical transient receptor potential channel 3 (TRPC3). These results are specific as randomization of ...

  18. Modelling the optical bleaching of a complex TL signal

    International Nuclear Information System (INIS)

    Thermoluminescence (TL) intensity decrease is observed in many materials after optical stimulation and is called optical bleaching of TL. The optical bleaching of a TL peak does not always mean that the traps responsible for this peak are emptied by stimulating light. The McKeever model explains TL bleaching by the emptying of deep thermally disconnected traps. The modification of this model is used for simulating the optical bleaching of complex TL curves in the case of complex TL spectrum. Some characteristic outcomes important for interpreting the results of TL optical bleaching measurements are reported

  19. Contributions and complexities from the use of in-vivo animal models to improve understanding of human neuroimaging signals.

    Directory of Open Access Journals (Sweden)

    ChrisMartin

    2014-08-01

    Full Text Available Many of the major advances in our understanding of how functional brain imaging signals relate to neuronal activity over the previous two decades have arisen from physiological research studies involving experimental animal models. This approach has been successful partly because it provides opportunities to measure both the hemodynamic changes that underpin many human functional brain imaging techniques and the neuronal activity about which we wish to make inferences. Although research into the coupling of neuronal and hemodynamic responses using animal models has provided a general validation of the correspondence of neuroimaging signals to specific types of neuronal activity, it is also highlighting the key complexities and uncertainties in estimating neural signals from hemodynamic markers. This review will detail how research in animal models is contributing to our rapidly evolving understanding of what human neuroimaging techniques tell us about neuronal activity. It will highlight emerging issues in the interpretation of neuroimaging data that arise from in-vivo research studies, for example spatial and temporal constraints to neuroimaging signal interpretation, or the effects of disease and modulatory neurotransmitters upon neurovascular coupling. We will also give critical consideration to the limitations and possible complexities of translating data acquired in the typical animals models used in this area to the arena of human fMRI. These include the commonplace use of anaesthesia in animal research studies and the fact that many neuropsychological questions that are being actively explored in humans have limited homologues within current animal models for neuroimaging research. Finally we will highlighting approaches, both in experimental animals models (e.g. imaging in conscious, behaving animals and human studies (e.g. combined fMRI-EEG, that mitigate against these challenges.

  20. Differential erbB signaling in astrocytes from the cerebral cortex and the hypothalamus of the human brain. : ErbB signaling in human astrocytes

    OpenAIRE

    Sharif, Ariane; Duhem-Tonnelle, Véronique; Allet, Cécile; Baroncini, Marc; Loyens, Anne; Kerr-Conte, Julie; Collier, Francis; Blond, Serge; Ojeda, Sergio; Junier, Marie-Pierre; Prévot, Vincent

    2009-01-01

    Studies in rodents have shown that astroglial erbB tyrosine kinase receptors are key regulatory elements in neuron-glia communication. Although both astrocytes and deregulation of erbB functions have been implicated in the pathogenesis of many common human brain disorders, erbB signaling in native human brain astrocytes has never been explored. Taking advantage of our ability to perform primary cultures from the cortex and the hypothalamus of human fetuses, we conducted a thorough analysis of...

  1. Free-running ADC- and FPGA-based signal processing method for brain PET using GAPD arrays

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Wei [Department of Electronic Engineering, Sogang University, 1 Shinsu-Dong, Mapo-Gu, Seoul 121-742 (Korea, Republic of); Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-Dong, Gangnam-Gu, Seoul 135-710 (Korea, Republic of); Choi, Yong, E-mail: ychoi.image@gmail.com [Department of Electronic Engineering, Sogang University, 1 Shinsu-Dong, Mapo-Gu, Seoul 121-742 (Korea, Republic of); Hong, Key Jo [Department of Electronic Engineering, Sogang University, 1 Shinsu-Dong, Mapo-Gu, Seoul 121-742 (Korea, Republic of); Kang, Jihoon [Department of Electronic Engineering, Sogang University, 1 Shinsu-Dong, Mapo-Gu, Seoul 121-742 (Korea, Republic of); Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-Dong, Gangnam-Gu, Seoul 135-710 (Korea, Republic of); Jung, Jin Ho [Department of Electronic Engineering, Sogang University, 1 Shinsu-Dong, Mapo-Gu, Seoul 121-742 (Korea, Republic of); Huh, Youn Suk [Department of Electronic Engineering, Sogang University, 1 Shinsu-Dong, Mapo-Gu, Seoul 121-742 (Korea, Republic of); Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-Dong, Gangnam-Gu, Seoul 135-710 (Korea, Republic of); Lim, Hyun Keong; Kim, Sang Su [Department of Electronic Engineering, Sogang University, 1 Shinsu-Dong, Mapo-Gu, Seoul 121-742 (Korea, Republic of); Kim, Byung-Tae [Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-Dong, Gangnam-Gu, Seoul 135-710 (Korea, Republic of); Chung, Yonghyun [Department of Radiological Science, Yonsei University College of Health Science, 234 Meaji, Heungup Wonju, Kangwon-Do 220-710 (Korea, Republic of)

    2012-02-01

    then transferred to a host computer for coincidence sorting and image reconstruction. In order to evaluate the functionality of the developed signal processing method, energy and timing resolutions for brain PET were measured via the placement of a 6 {mu}Ci {sup 22}Na point source at the center of the PET scanner. Furthermore the PET image of the hot rod phantom (rod diameter: from 2.5 mm to 6.5 mm) with activity of 1 mCi was simulated, and then image acquisition experiment was performed using the brain PET. Measured average energy resolution for 1152 GAPD channels and system timing resolution were 19.5% (FWHM%) and 2.7 ns (FWHM), respectively. With regard to the acquisition of the hot rod phantom image, rods could be resolved down to a diameter of 2.5 mm, which was similar to simulated results. The experimental results demonstrated that the signal processing method developed herein was successfully implemented for brain PET. This reduced the complexity, cost and developing duration for PET system relative to normal PET electronics, and it will obviously be useful for the development of high-performance investigational PET systems.

  2. Free-running ADC- and FPGA-based signal processing method for brain PET using GAPD arrays

    International Nuclear Information System (INIS)

    evaluate the functionality of the developed signal processing method, energy and timing resolutions for brain PET were measured via the placement of a 6 μCi 22Na point source at the center of the PET scanner. Furthermore the PET image of the hot rod phantom (rod diameter: from 2.5 mm to 6.5 mm) with activity of 1 mCi was simulated, and then image acquisition experiment was performed using the brain PET. Measured average energy resolution for 1152 GAPD channels and system timing resolution were 19.5% (FWHM%) and 2.7 ns (FWHM), respectively. With regard to the acquisition of the hot rod phantom image, rods could be resolved down to a diameter of 2.5 mm, which was similar to simulated results. The experimental results demonstrated that the signal processing method developed herein was successfully implemented for brain PET. This reduced the complexity, cost and developing duration for PET system relative to normal PET electronics, and it will obviously be useful for the development of high-performance investigational PET systems.

  3. In vivo photoacoustic neuronal imaging of odor-evoked calcium signals in the drosophila brain (Conference Presentation)

    Science.gov (United States)

    Zhang, Ruiying; Rao, Bin; Rong, Haoyang; Raman, Baranidharan; Wang, Lihong V.

    2016-03-01

    Neural scientists can benefit greatly from imaging tools that can penetrate thick brain tissue. Compared with traditional optical microscopy methods, photoacoustic imaging can beat the optical diffusion limit and achieve such deep tissue imaging with high spatial resolution. In this study, we used an optical-resolution photoacoustic microscope to image the odor-evoked neuronal activities in a drosophila model. Drosophila brain neurons stably express GCaMP5G, a calcium-sensitive fluorescent protein whose optical absorption coefficient changes with calcium influx during action potentials. We recorded an ~20% odor-evoked fractional photoacoustic signal increase at all depths of the drosophila brain in vivo, with and without removal of the brain cuticle, at a recording rate of 1 kHz. Our results were confirmed by concurrent fluorescent recordings. Furthermore, by performing fast 2D scanning, we imaged the antenna lobe region, which is of particular interest in neuroscience, at a volumetric rate of ~1 Hz with a sub-neuron resolution of 3 μm. Unlike optical imaging, which requires surgical removal of the scattering brain cuticle, our photoacoustic system can image through the cuticle and measure neuronal signals of the whole drosophila brain without invasive surgery, enabling minimal disturbance to the animal's behaviors. In conclusion, we have demonstrated photoacoustic imaging of calcium signals in drosophila brains for the first time. Utilizing the deep imaging capability of photoacoustic tomography, our methods could potentially be extended to in vivo imaging of neuronal activities from deep brains in other animal models.

  4. In vivo optical microprobe imaging for intracellular Ca2+ dynamics in response to dopaminergic signaling in deep brain evoked by cocaine

    Science.gov (United States)

    Luo, Zhongchi; Pan, Yingtian; Du, Congwu

    2012-02-01

    Ca2+ plays a vital role as second messenger in signal transduction and the intracellular Ca2+ ([Ca2+]i) change is an important indicator of neuronal activity in the brain, including both cortical and subcortical brain regions. Due to the highly scattering and absorption of brain tissue, it is challenging to optically access the deep brain regions (e.g., striatum at >3mm under the brain surface) and image [Ca2+]i changes with cellular resolutions. Here, we present two micro-probe approaches (i.e., microlens, and micro-prism) integrated with a fluorescence microscope modified to permit imaging of neuronal [Ca2+]i signaling in the striatum using a calcium indicator Rhod2(AM). While a micro-prism probe provides a larger field of view to image neuronal network from cortex to striatum, a microlens probe enables us to track [Ca2+]i dynamic change in individual neurons within the brain. Both techniques are validated by imaging neuronal [Ca2+]i changes in transgenic mice with dopamine receptors (D1R, D2R) expressing EGFP. Our results show that micro-prism images can map the distribution of D1R- and D2R-expressing neurons in various brain regions and characterize their different mean [Ca2+]i changes induced by an intervention (e.g., cocaine administration, 8mg/kg., i.p). In addition, microlens images can characterize the different [Ca2+]i dynamics of D1 and D2 neurons in response to cocaine, including new mechanisms of these two types of neurons in striatum. These findings highlight the power of the optical micro-probe imaging for dissecting the complex cellular and molecular insights of cocaine in vivo.

  5. On the space and time evolution of regular or irregular human heart or brain signals

    CERN Document Server

    Tuncay, Caglar

    2011-01-01

    A coupled map is suggested to investigate various spatial or temporal designs in biology: Several cells (or tissues) in an organ are considered as connected to each other in terms of some molecular diffusions or electrical potential differences and so on. The biological systems (groups of cells) start from various initial conditions for spatial designs (or initial signals for temporal designs) and they evolve in time in terms of the mentioned interactions (connections) besides some individual feedings. The basic aim of the present contribution is to mimic various empirical data for the heart (in normal, quasi-stable, unstable and post operative physiological conditions) or brain (regular or irregular; for epilepsy) signals. The mentioned empirical data are borrowed from various literatures which are cited. The suggested model (to be used besides or instead of the artificial network models) involves simple mathematics and the related software is easy. The results may be considered as in good agreement with the...

  6. Protease activated receptor signaling is required for African trypanosome traversal of human brain microvascular endothelial cells.

    Directory of Open Access Journals (Sweden)

    Dennis J Grab

    Full Text Available BACKGROUND: Using human brain microvascular endothelial cells (HBMECs as an in vitro model for how African trypanosomes cross the human blood-brain barrier (BBB we recently reported that the parasites cross the BBB by generating calcium activation signals in HBMECs through the activity of parasite cysteine proteases, particularly cathepsin L (brucipain. In the current study, we examined the possible role of a class of protease stimulated HBMEC G protein coupled receptors (GPCRs known as protease activated receptors (PARs that might be implicated in calcium signaling by African trypanosomes. METHODOLOGY/PRINCIPAL FINDINGS: Using RNA interference (RNAi we found that in vitro PAR-2 gene (F2RL1 expression in HBMEC monolayers could be reduced by over 95%. We also found that the ability of Trypanosoma brucei rhodesiense to cross F2RL1-silenced HBMEC monolayers was reduced (39%-49% and that HBMECs silenced for F2RL1 maintained control levels of barrier function in the presence of the parasite. Consistent with the role of PAR-2, we found that HBMEC barrier function was also maintained after blockade of Galpha(q with Pasteurella multocida toxin (PMT. PAR-2 signaling has been shown in other systems to have neuroinflammatory and neuroprotective roles and our data implicate a role for proteases (i.e. brucipain and PAR-2 in African trypanosome/HBMEC interactions. Using gene-profiling methods to interrogate candidate HBMEC pathways specifically triggered by brucipain, several pathways that potentially link some pathophysiologic processes associated with CNS HAT were identified. CONCLUSIONS/SIGNIFICANCE: Together, the data support a role, in part, for GPCRs as molecular targets for parasite proteases that lead to the activation of Galpha(q-mediated calcium signaling. The consequence of these events is predicted to be increased permeability of the BBB to parasite transmigration and the initiation of neuroinflammation, events precursory to CNS disease.

  7. The Trees and the Forest: Characterization of complex brain networks with minimum spanning trees

    NARCIS (Netherlands)

    Stam, C.J.; Tewarie, P.; Van Dellen, E.; Van Straaten, E.C.W.; Hillebrand, A.; Van Mieghem, P.

    2014-01-01

    In recent years there has been a shift in focus from the study of local, mostly task-related activation to the exploration of the organization and functioning of large-scale structural and functional complex brain networks. Progress in the interdisciplinary field of modern network science has introd

  8. Method for analyzing signaling networks in complex cellular systems.

    Science.gov (United States)

    Plavec, Ivan; Sirenko, Oksana; Privat, Sylvie; Wang, Yuker; Dajee, Maya; Melrose, Jennifer; Nakao, Brian; Hytopoulos, Evangelos; Berg, Ellen L; Butcher, Eugene C

    2004-02-01

    Now that the human genome has been sequenced, the challenge of assigning function to human genes has become acute. Existing approaches using microarrays or proteomics frequently generate very large volumes of data not directly related to biological function, making interpretation difficult. Here, we describe a technique for integrative systems biology in which: (i) primary cells are cultured under biologically meaningful conditions; (ii) a limited number of biologically meaningful readouts are measured; and (iii) the results obtained under several different conditions are combined for analysis. Studies of human endothelial cells overexpressing different signaling molecules under multiple inflammatory conditions show that this system can capture a remarkable range of functions by a relatively small number of simple measurements. In particular, measurement of seven different protein levels by ELISA under four different conditions is capable of reconstructing pathway associations of 25 different proteins representing four known signaling pathways, implicating additional participants in the NF-kappaBorRAS/mitogen-activated protein kinase pathways and defining additional interactions between these pathways. PMID:14745015

  9. Quantitative Analysis of Diffusion Weighted MR Images of Brain Tumor Using Signal Intensity Gradient Technique

    Directory of Open Access Journals (Sweden)

    S. S. Shanbhag

    2014-01-01

    Full Text Available The purpose of this study was to evaluate the role of diffusion weighted-magnetic resonance imaging (DW-MRI in the examination and classification of brain tumors, namely, glioma and meningioma. Our hypothesis was that as signal intensity variations on diffusion weighted (DW images depend on histology and cellularity of the tumor, analysing the signal intensity characteristics on DW images may allow differentiating between the tumor types. Towards this end the signal intensity variations on DW images of the entire tumor volume data of 20 subjects with glioma and 12 subjects with meningioma were investigated and quantified using signal intensity gradient (SIG parameter. The relative increase in the SIG values (RSIG for the subjects with glioma and meningioma was in the range of 10.08–28.36 times and 5.60–9.86 times, respectively, compared to their corresponding SIG values on the contralateral hemisphere. The RSIG values were significantly different between the subjects with glioma and meningioma (P<0.01, with no overlap between RSIG values across the two tumors. The results indicate that the quantitative changes in the RSIG values could be applied in the differential diagnosis of glioma and meningioma, and their adoption in clinical diagnosis and treatment could be helpful and informative.

  10. Investigating Irregularly Patterned Deep Brain Stimulation Signal Design Using Biophysical Models

    Directory of Open Access Journals (Sweden)

    Samantha Rose Summerson

    2015-06-01

    Full Text Available Parkinson’s disease (PD is a neurodegenerative disorder which follows from cell loss of dopaminergic neurons in the substantia nigra pars compacta (SNc, a nucleus in the basal ganglia (BG. Deep brain stimulation (DBS is an electrical therapy that modulates the pathological activity to treat the motor symptoms of PD. Although this therapy is currently used in clinical practice, the sufficient conditions for therapeutic efficacy are unknown. In this work we develop a model of critical motor circuit structures in the brain using biophysical cell models as the base components and then evaluate performance of different DBS signals in this model to perform comparative studies of their efficacy. Biological models are an important tool for gaining insights into neural function and, in this case, serve as effective tools for investigating innovative new DBS paradigms. Experiments were performed using the hemi-parkinsonian rodent model to test the same set of signals, verifying the obedience of the model to physiological trends. We show that antidromic spiking from DBS of the subthalamic nucleus (STN has a significant impact on cortical neural activity, which is frequency dependent and additionally modulated by the regularity of the stimulus pulse train used. Irregular spacing between stimulus pulses, where the amount of variability added is bounded, is shown to increase diversification of response of basal ganglia neurons and reduce entropic noise in cortical neurons, which may be fundamentally important to restoration of information flow in the motor circuit.

  11. Oligodendrocyte precursor cells support blood-brain barrier integrity via TGF-β signaling.

    Directory of Open Access Journals (Sweden)

    Ji Hae Seo

    Full Text Available Trophic coupling between cerebral endothelium and their neighboring cells is required for the development and maintenance of blood-brain barrier (BBB function. Here we report that oligodendrocyte precursor cells (OPCs secrete soluble factor TGF-β1 to support BBB integrity. Firstly, we prepared conditioned media from OPC cultures and added them to cerebral endothelial cultures. Our pharmacological experiments showed that OPC-conditioned media increased expressions of tight-junction proteins and decreased in vitro BBB permeability by activating TGB-β-receptor-MEK/ERK signaling pathway. Secondly, our immuno-electron microscopic observation revealed that in neonatal mouse brains, OPCs attach to cerebral endothelial cells via basal lamina. And finally, we developed a novel transgenic mouse line that TGF-β1 is knocked down specifically in OPCs. Neonates of these OPC-specific TGF-β1 deficient mice (OPC-specific TGF-β1 partial KO mice: PdgfraCre/Tgfb1flox/wt mice or OPC-specific TGF-β1 total KO mice: PdgfraCre/Tgfb1flox/flox mice exhibited cerebral hemorrhage and loss of BBB function. Taken together, our current study demonstrates that OPCs increase BBB tightness by upregulating tight junction proteins via TGF-β signaling. Although astrocytes and pericytes are well-known regulators of BBB maturation and maintenance, these findings indicate that OPCs also play a pivotal role in promoting BBB integrity.

  12. From phenotype to genotype in complex brain networks

    Science.gov (United States)

    Zanin, Massimiliano; Correia, Marco; Sousa, Pedro A. C.; Cruz, Jorge

    2016-01-01

    Generative models are a popular instrument for illuminating the relationships between the hidden variables driving the growth of a complex network and its final topological characteristics, a process known as the “genotype to phenotype problem”. However, the definition of a complete methodology encompassing all stages of the analysis, and in particular the validation of the final model, is still an open problem. We here discuss a framework that allows to quantitatively optimise and validate each step of the model creation process. It is based on the execution of a classification task, and on estimating the additional precision provided by the modelled genotype. This encompasses the three main steps of the model creation, namely the selection of topological features, the optimisation of the parameters of the generative model, and the validation of the obtained results. We provide a minimum requirement for a generative model to be useful, prescribing the function mapping genotype to phenotype to be non-monotonic; and we further show how a previously published model does not fulfil such condition, casting doubts on its fitness for the study of neurological disorders. The generality of such framework guarantees its applicability beyond neuroscience, like the emergence of social or technological networks.

  13. Classification of Brain Signals in Normal Subjects and Patients with Epilepsy Using Mixture of Experts

    Directory of Open Access Journals (Sweden)

    S. Amoozegar

    2013-06-01

    Full Text Available EEG is one of the most important and common sources for study of brain function and neurological disorders. Automated systems are under study for many years to detect EEG changes. Because of the importance of making correct decision, we are looking for better classification methods for EEG signals. In this paper a smart compound system is used for classifying EEG signals to different groups. Since in each classification the system accuracy of making decision is very important, in this study we look for some methods to improve the accuracy of EEG signals classification. In this paper the use of Mixture of Experts for improving the EEG signals classification of normal subjects and patients with epilepsy is shown and the classification accuracy is evaluated. Decision making was performed in two stages: 1 feature extractions with different methods of eigenvector and 2 Classification using the classifier trained by extracted features. This smart system inputs are formed from composites features that are selected appropriate with network structure. In this study tree methods based on eigenvectors (Minimum Norm, MUSIC, Pisarenko are chosen for the estimation of Power Spectral Density (PSD. After the implementation of ME and train it on composite features, we propose that this technique can reach high classification accuracy. Hence, EEG signals classification of epilepsy patients in different situations and control subjects is available. In this study, Mixture of Experts structure was used for EEG signals classification. Proper performance of Neural Network depends on the size of train and test data. Combination of multiple Neural Networks even without using the probable structure in obtaining weights in classification problem can produce high accuracy in less time, which is important and valuable in the classification point of view.

  14. Lineage-based analysis of the development of the central complex of the Drosophila brain.

    Science.gov (United States)

    Pereanu, Wayne; Younossi-Hartenstein, Amelia; Lovick, Jennifer; Spindler, Shana; Hartenstein, Volker

    2011-03-01

    Most neurons of the central complex belong to 10 secondary (larvally produced) lineages. In the late larva, undifferentiated axon tracts of these lineages form a primordium in which all of the compartments of the central complex can be recognized as discrete entities. Four posterior lineages (DPMm1, DPMpm1, DPMpm2, and CM4) generate the classes of small-field neurons that interconnect the protocerebral bridge, fan-shaped body, noduli, and ellipsoid body. Three lineages located in the anterior brain, DALv2, BAmv1, and DALcl2, form the large-field neurons of the ellipsoid body and fan-shaped body, respectively. These lineages provide an input channel from the optic tubercle and connect the central complex with adjacent anterior brain compartments. Three lineages in the posterior cortex, CM3, CP2, and DPMpl2, connect the posterior brain neuropil with specific layers of the fan-shaped body. Even though all of the compartments of the central complex are prefigured in the late larval brain by the axon tracts of the above-mentioned lineages, the neuropil differentiates during the first 2 days of the pupal period when terminal branches and synapses of secondary neurons are formed. During this phase the initially straight horizontal layers of the central complex bend in the frontal plane, which produces the characteristic shape of the fan-shaped and ellipsoid body. Our analysis provides a comprehensive picture of the lineages that form the central complex, and will facilitate future studies that address the structure or function of the central complex at the single cell level. PMID:21246549

  15. Brain serotonin signaling does not determine sexual preference in male mice.

    Directory of Open Access Journals (Sweden)

    Mariana Angoa-Pérez

    Full Text Available It was reported recently that male mice lacking brain serotonin (5-HT lose their preference for females (Liu et al., 2011, Nature, 472, 95-100, suggesting a role for 5-HT signaling in sexual preference. Regulation of sex preference by 5-HT lies outside of the well established roles in this behavior established for the vomeronasal organ (VNO and the main olfactory epithelium (MOE. Presently, mice with a null mutation in the gene for tryptophan hydroxylase 2 (TPH2, which are depleted of brain 5-HT, were tested for sexual preference. When presented with inanimate (urine scents from male or estrous female or animate (male or female mouse in estrus sexual stimuli, TPH2-/- males show a clear preference for female over male stimuli. When a TPH2-/- male is offered the simultaneous choice between an estrous female and a male mouse, no sexual preference is expressed. However, when confounding behaviors that are seen among 3 mice in the same cage are controlled, TPH2-/- mice, like their TPH2+/+ counterparts, express a clear preference for female mice. Female TPH2-/- mice are preferred by males over TPH2+/+ females but this does not lead to increased pregnancy success. In fact, if one or both partners in a mating pair are TPH2-/- in genotype, pregnancy success rates are significantly decreased. Finally, expression of the VNO-specific cation channel TRPC2 and of CNGA2 in the MOE of TPH2-/- mice is normal, consistent with behavioral findings that sexual preference of TPH2-/- males for females is intact. In conclusion, 5-HT signaling in brain does not determine sexual preference in male mice. The use of pharmacological agents that are non-selective for the 5-HT neuronal system and that have serious adverse effects may have contributed historically to the stance that 5-HT regulates sexual behavior, including sex partner preference.

  16. Brain serotonin signaling does not determine sexual preference in male mice.

    Science.gov (United States)

    Angoa-Pérez, Mariana; Herrera-Mundo, Nieves; Kane, Michael J; Sykes, Catherine E; Anneken, John H; Francescutti, Dina M; Kuhn, Donald M

    2015-01-01

    It was reported recently that male mice lacking brain serotonin (5-HT) lose their preference for females (Liu et al., 2011, Nature, 472, 95-100), suggesting a role for 5-HT signaling in sexual preference. Regulation of sex preference by 5-HT lies outside of the well established roles in this behavior established for the vomeronasal organ (VNO) and the main olfactory epithelium (MOE). Presently, mice with a null mutation in the gene for tryptophan hydroxylase 2 (TPH2), which are depleted of brain 5-HT, were tested for sexual preference. When presented with inanimate (urine scents from male or estrous female) or animate (male or female mouse in estrus) sexual stimuli, TPH2-/- males show a clear preference for female over male stimuli. When a TPH2-/- male is offered the simultaneous choice between an estrous female and a male mouse, no sexual preference is expressed. However, when confounding behaviors that are seen among 3 mice in the same cage are controlled, TPH2-/- mice, like their TPH2+/+ counterparts, express a clear preference for female mice. Female TPH2-/- mice are preferred by males over TPH2+/+ females but this does not lead to increased pregnancy success. In fact, if one or both partners in a mating pair are TPH2-/- in genotype, pregnancy success rates are significantly decreased. Finally, expression of the VNO-specific cation channel TRPC2 and of CNGA2 in the MOE of TPH2-/- mice is normal, consistent with behavioral findings that sexual preference of TPH2-/- males for females is intact. In conclusion, 5-HT signaling in brain does not determine sexual preference in male mice. The use of pharmacological agents that are non-selective for the 5-HT neuronal system and that have serious adverse effects may have contributed historically to the stance that 5-HT regulates sexual behavior, including sex partner preference. PMID:25706994

  17. Brain signal variability as a window into the bidirectionality between music and language processing: moving from a linear to a nonlinear model

    Science.gov (United States)

    Hutka, Stefanie; Bidelman, Gavin M.; Moreno, Sylvain

    2013-01-01

    There is convincing empirical evidence for bidirectional transfer between music and language, such that experience in either domain can improve mental processes required by the other. This music-language relationship has been studied using linear models (e.g., comparing mean neural activity) that conceptualize brain activity as a static entity. The linear approach limits how we can understand the brain’s processing of music and language because the brain is a nonlinear system. Furthermore, there is evidence that the networks supporting music and language processing interact in a nonlinear manner. We therefore posit that the neural processing and transfer between the domains of language and music are best viewed through the lens of a nonlinear framework. Nonlinear analysis of neurophysiological activity may yield new insight into the commonalities, differences, and bidirectionality between these two cognitive domains not measurable in the local output of a cortical patch. We thus propose a novel application of brain signal variability (BSV) analysis, based on mutual information and signal entropy, to better understand the bidirectionality of music-to-language transfer in the context of a nonlinear framework. This approach will extend current methods by offering a nuanced, network-level understanding of the brain complexity involved in music-language transfer. PMID:24454295

  18. Brain signal variability as a window into the bidirectionality between music and language processing: Moving from a linear to a nonlinear model

    Directory of Open Access Journals (Sweden)

    StefanieAndreaHutka

    2013-12-01

    Full Text Available There is convincing empirical evidence for bidirectional transfer between music and language, such that experience in either domain can improve mental processes required by the other. This music-language relationship has been studied using linear models (e.g., comparing mean neural activity that conceptualize brain activity as a static entity. The linear approach limits how we can understand the brain’s processing of music and language because the brain is a nonlinear system. Furthermore, there is evidence that the networks supporting music and language processing interact in a nonlinear manner. We therefore posit that the neural processing and transfer between the domains of language and music are best viewed through the lens of a nonlinear framework. Nonlinear analysis of neurophysiological activity may yield new insight into the commonalities, differences, and bidirectionality between these two cognitive domains not measurable in the local output of a cortical patch. We thus propose a novel application of brain signal variability (BSV analysis, based on mutual information and signal entropy, to better understand the bidirectionality of music-to-language transfer in the context of a nonlinear framework. This approach will extend current methods by offering a nuanced, network-level understanding of the brain complexity involved in music-language transfer.

  19. Eph receptor and ephrin signaling in developing and adult brain of the honeybee (Apis mellifera).

    Science.gov (United States)

    Vidovic, Maria; Nighorn, Alan; Koblar, Simon; Maleszka, Ryszard

    2007-02-01

    Roles for Eph receptor tyrosine kinase and ephrin signaling in vertebrate brain development are well established. Their involvement in the modulation of mammalian synaptic structure and physiology is also emerging. However, less is known of their effects on brain development and their function in adult invertebrate nervous systems. Here, we report on the characterization of Eph receptor and ephrin orthologs in the honeybee, Apis mellifera (Am), and their role in learning and memory. In situ hybridization for mRNA expression showed a uniform distribution of expression of both genes across the developing pupal and adult brain. However, in situ labeling with Fc fusion proteins indicated that the AmEphR and Amephrin proteins were differentially localized to cell body regions in the mushroom bodies and the developing neuropiles of the antennal and optic lobes. In adults, AmEphR protein was localized to regions of synaptic contacts in optic lobes, in the glomeruli of antennal lobes, and in the medial lobe of the mushroom body. The latter two regions are involved in olfactory learning and memory in the honeybee. Injections of EphR-Fc and ephrin-Fc proteins into the brains of adult bees, 1 h before olfactory conditioning of the proboscis extension reflex, significantly reduced memory 24 h later. Experimental amnesia in the group injected with ephrin-Fc was apparent 1 h post-training. Experimental amnesia was also induced by post-training injections with ephrin-Fc suggesting a role in recall. This is the first demonstration that Eph molecules function to regulate the formation of memory in insects. PMID:17443785

  20. A stochastic mechanism for signal propagation in the brain: Force of rapid random fluctuations in membrane potentials of individual neurons.

    Science.gov (United States)

    Hong, Dawei; Man, Shushuang; Martin, Joseph V

    2016-01-21

    There are two functionally important factors in signal propagation in a brain structural network: the very first synaptic delay-a time delay about 1ms-from the moment when signals originate to the moment when observation on the signal propagation can begin; and rapid random fluctuations in membrane potentials of every individual neuron in the network at a timescale of microseconds. We provide a stochastic analysis of signal propagation in a general setting. The analysis shows that the two factors together result in a stochastic mechanism for the signal propagation as described below. A brain structural network is not a rigid circuit rather a very flexible framework that guides signals to propagate but does not guarantee success of the signal propagation. In such a framework, with the very first synaptic delay, rapid random fluctuations in every individual neuron in the network cause an "alter-and-concentrate effect" that almost surely forces signals to successfully propagate. By the stochastic mechanism we provide analytic evidence for the existence of a force behind signal propagation in a brain structural network caused by rapid random fluctuations in every individual neuron in the network at a timescale of microseconds with a time delay of 1ms. PMID:26555846

  1. Modeling and Rotor Current Control of Doubly-fed Induction Machine with Complex Signal Flow Graphs

    OpenAIRE

    Khambadkone, AM; Datta, Rajib; Ranganathan, VT

    1998-01-01

    Doubly fed induction machine can be used for wind energy generation. The control of rotor currents can facilitate variable speed constant frequency operation at unity power factor. A model based on complex signal flow graph is developed. This leads to a physically insightful control structure of the machine. A rotor current control strategy based on the complex signal flow graph is developed to facilitate fast current control. The paper gives the analysis, design and simulation for rotor curr...

  2. Wnt signalling induces accumulation of phosphorylated β-catenin in two distinct cytosolic complexes

    OpenAIRE

    Gerlach, Jan P.; Emmink, Benjamin L; Nojima, Hisashi; Kranenburg, Onno; Maurice, Madelon M.

    2014-01-01

    Wnt/β-catenin signalling controls development and adult tissue homeostasis and causes cancer when inappropriately activated. In unstimulated cells, an Axin1-centred multi-protein complex phosphorylates the transcriptional co-activator β-catenin, marking it for degradation. Wnt signalling antagonizes β-catenin proteolysis, leading to its accumulation and target gene expression. How Wnt stimulation alters the size distribution, composition and activity of endogenous Axin1 complexes remains poor...

  3. Modulation of EEG Theta Band Signal Complexity by Music Therapy [Forthcoming

    OpenAIRE

    Bhattacharya, Joydeep; Lee, Eun-Jeong

    2012-01-01

    The primary goal of this study was to investigate the impact of monochord (MC) sounds, a type of archaic sounds used in music therapy, on the neural complexity of EEG signals obtained from patients undergoing chemotherapy. The secondary goal was to compare the EEG signal complexity values for monochords with those for progressive muscle relaxation (PMR), an alternative therapy for relaxation. Forty cancer patients were randomly allocated to one of the two relaxation groups, MC and PMR, over a...

  4. Quantitative complexity analysis in multi-channel intracranial EEG recordings form epilepsy brains

    Science.gov (United States)

    Liu, Chang-Chia; Pardalos, Panos M.; Chaovalitwongse, W. Art; Shiau, Deng-Shan; Ghacibeh, Georges; Suharitdamrong, Wichai; Sackellares, J. Chris

    2008-01-01

    Epilepsy is a brain disorder characterized clinically by temporary but recurrent disturbances of brain function that may or may not be associated with destruction or loss of consciousness and abnormal behavior. Human brain is composed of more than 10 to the power 10 neurons, each of which receives electrical impulses known as action potentials from others neurons via synapses and sends electrical impulses via a sing output line to a similar (the axon) number of neurons. When neuronal networks are active, they produced a change in voltage potential, which can be captured by an electroencephalogram (EEG). The EEG recordings represent the time series that match up to neurological activity as a function of time. By analyzing the EEG recordings, we sought to evaluate the degree of underlining dynamical complexity prior to progression of seizure onset. Through the utilization of the dynamical measurements, it is possible to classify the state of the brain according to the underlying dynamical properties of EEG recordings. The results from two patients with temporal lobe epilepsy (TLE), the degree of complexity start converging to lower value prior to the epileptic seizures was observed from epileptic regions as well as non-epileptic regions. The dynamical measurements appear to reflect the changes of EEG’s dynamical structure. We suggest that the nonlinear dynamical analysis can provide a useful information for detecting relative changes in brain dynamics, which cannot be detected by conventional linear analysis. PMID:19079790

  5. Abnormal EEG Complexity and Functional Connectivity of Brain in Patients with Acute Thalamic Ischemic Stroke

    Science.gov (United States)

    Liu, Shuang; Guo, Jie; Meng, Jiayuan; Wang, Zhijun; Yao, Yang; Yang, Jiajia; Qi, Hongzhi; Ming, Dong

    2016-01-01

    Ischemic thalamus stroke has become a serious cardiovascular and cerebral disease in recent years. To date the existing researches mostly concentrated on the power spectral density (PSD) in several frequency bands. In this paper, we investigated the nonlinear features of EEG and brain functional connectivity in patients with acute thalamic ischemic stroke and healthy subjects. Electroencephalography (EEG) in resting condition with eyes closed was recorded for 12 stroke patients and 11 healthy subjects as control group. Lempel-Ziv complexity (LZC), Sample Entropy (SampEn), and brain network using partial directed coherence (PDC) were calculated for feature extraction. Results showed that patients had increased mean LZC and SampEn than the controls, which implied the stroke group has higher EEG complexity. For the brain network, the stroke group displayed a trend of weaker cortical connectivity, which suggests a functional impairment of information transmission in cortical connections in stroke patients. These findings suggest that nonlinear analysis and brain network could provide essential information for better understanding the brain dysfunction in the stroke and assisting monitoring or prognostication of stroke evolution.

  6. Preparation of new technetium-99m NNS/X complexes and selection for brain imaging agent

    Institute of Scientific and Technical Information of China (English)

    HE; Qiange; CHEN; Xiangji; MIAO; Yubin; LIU; Boli

    2004-01-01

    Based on excellent experiment results of 99mTcO-MPBDA-Cl, two new ligands MPTDA and MPDAA are synthesized. Then series of 99mTcO3+ complexes are prepared through adding different halide anions, followed by tests of physical chemistry qualities and biodistribution experiments. And results of these experiments show that complexes formed with MPTDA and MPDAA have better lipophilicity than those formed with MPBDA, still maintain the good brain retention ability of this type of compounds, but radioactivity uptake in blood is higher than that of 99mTcO-MPBDA and ratios of brain/blood are reduced. Obvious affections are fetched out on brain uptake and retention if fluoride, bromide or iodide anions are added. Results of experiments can be explained in reason with theoretic computation. It is confirmed that 99mTcO-MPBDA-Cl has potential to develop a new type of brain imaging agent considering integrated factors such as brain uptake, retention and toxicity.

  7. Unraveling the Complexities of Androgen Receptor Signaling in Prostate Cancer Cells

    OpenAIRE

    Heemers, Hannelore V.; Tindall, Donald J.

    2009-01-01

    Androgen signaling is critical for proliferation of prostate cancer cells but cannot be fully inhibited by current androgen deprivation therapies. A study by Xu et al. in this issue of Cancer Cell provides insights into the complexities of androgen signaling in prostate cancer and suggests avenues to target a subset of androgen-sensitive genes.

  8. Videogame training strategy-induced change in brain function during a complex visuomotor task.

    Science.gov (United States)

    Lee, Hyunkyu; Voss, Michelle W; Prakash, Ruchika Shaurya; Boot, Walter R; Vo, Loan T K; Basak, Chandramallika; Vanpatter, Matt; Gratton, Gabriele; Fabiani, Monica; Kramer, Arthur F

    2012-07-01

    Although changes in brain function induced by cognitive training have been examined, functional plasticity associated with specific training strategies is still relatively unexplored. In this study, we examined changes in brain function during a complex visuomotor task following training using the Space Fortress video game. To assess brain function, participants completed functional magnetic resonance imaging (fMRI) before and after 30 h of training with one of two training regimens: Hybrid Variable-Priority Training (HVT), with a focus on improving specific skills and managing task priority, or Full Emphasis Training (FET), in which participants simply practiced the game to obtain the highest overall score. Control participants received only 6 h of FET. Compared to FET, HVT learners reached higher performance on the game and showed less brain activation in areas related to visuo-spatial attention and goal-directed movement after training. Compared to the control group, HVT exhibited less brain activation in right dorsolateral prefrontal cortex (DLPFC), coupled with greater performance improvement. Region-of-interest analysis revealed that the reduction in brain activation was correlated with improved performance on the task. This study sheds light on the neurobiological mechanisms of improved learning from directed training (HVT) over non-directed training (FET), which is related to visuo-spatial attention and goal-directed motor planning, while separating the practice-based benefit, which is related to executive control and rule management. PMID:22504276

  9. The application of graph theoretical analysis to complex networks in the brain.

    Science.gov (United States)

    Reijneveld, Jaap C; Ponten, Sophie C; Berendse, Henk W; Stam, Cornelis J

    2007-11-01

    Considering the brain as a complex network of interacting dynamical systems offers new insights into higher level brain processes such as memory, planning, and abstract reasoning as well as various types of brain pathophysiology. This viewpoint provides the opportunity to apply new insights in network sciences, such as the discovery of small world and scale free networks, to data on anatomical and functional connectivity in the brain. In this review we start with some background knowledge on the history and recent advances in network theories in general. We emphasize the correlation between the structural properties of networks and the dynamics of these networks. We subsequently demonstrate through evidence from computational studies, in vivo experiments, and functional MRI, EEG and MEG studies in humans, that both the functional and anatomical connectivity of the healthy brain have many features of a small world network, but only to a limited extent of a scale free network. The small world structure of neural networks is hypothesized to reflect an optimal configuration associated with rapid synchronization and information transfer, minimal wiring costs, resilience to certain types of damage, as well as a balance between local processing and global integration. Eventually, we review the current knowledge on the effects of focal and diffuse brain disease on neural network characteristics, and demonstrate increasing evidence that both cognitive and psychiatric disturbances, as well as risk of epileptic seizures, are correlated with (changes in) functional network architectural features. PMID:17900977

  10. Apo-ghrelin receptor (apo-GHSR1a Regulates Dopamine Signaling in the Brain

    Directory of Open Access Journals (Sweden)

    Andras eKern

    2014-08-01

    Full Text Available The orexigenic peptide hormone ghrelin is synthesized in the stomach and its receptor growth hormone secretagogue receptor (GHSR1a is expressed mainly in the central nervous system (CNS. In this review we confine our discussion to the physiological role of GHSR1a in the brain. Paradoxically, despite broad expression of GHSR1a in the CNS, other than trace amounts in the hypothalamus, ghrelin is undetectable in the brain. In our efforts to elucidate the function of the ligand-free ghrelin receptor (apo-GHSR1a we identified subsets of neurons that co-express GHSR1a and dopamine receptors. In this review we focus on interactions between apo-GHSR1a and dopamine-2 receptor (DRD2 and formation of GHSR1a:DRD2 heteromers in hypothalamic neurons that regulate appetite, and discuss implications for the treatment of Prader-Willi syndrome. GHSR1a antagonists of distinct chemical structures, a quinazolinone and a triazole, respectively enhance and inhibit dopamine signaling through GHSR1a:DRD2 heteromers by an allosteric mechanism. This finding illustrates a potential strategy for designing the next generation of drugs for treating eating disorders as well as psychiatric disorders caused by abnormal dopamine signaling. Treatment with a GHSR1a antagonist that enhances dopamine/DRD2 activity in GHSR1a:DRD2 expressing hypothalamic neurons has the potential to inhibit the uncontrollable hyperphagia associated with Prader-Willi syndrome. DRD2 antagonists are prescribed for treating schizophrenia, but these block dopamine signaling in all DRD2 expressing neurons and are associated with adverse side effects, including enhanced appetite and excessive weight gain. A GHSR1a antagonist of structural class that allosterically blocks dopamine/DRD2 action in GHSR1a:DRD2 expressing neurons would have no effect on neurons expressing DRD2 alone; therefore, the side effects of DRD2 antagonists would potentially be reduced thereby enhancing patient compliance.

  11. Comparison of Matching Pursuit Algorithm with Other Signal Processing Techniques for Computation of the Time-Frequency Power Spectrum of Brain Signals.

    Science.gov (United States)

    Chandran Ks, Subhash; Mishra, Ashutosh; Shirhatti, Vinay; Ray, Supratim

    2016-03-23

    Signals recorded from the brain often show rhythmic patterns at different frequencies, which are tightly coupled to the external stimuli as well as the internal state of the subject. In addition, these signals have very transient structures related to spiking or sudden onset of a stimulus, which have durations not exceeding tens of milliseconds. Further, brain signals are highly nonstationary because both behavioral state and external stimuli can change on a short time scale. It is therefore essential to study brain signals using techniques that can represent both rhythmic and transient components of the signal, something not always possible using standard signal processing techniques such as short time fourier transform, multitaper method, wavelet transform, or Hilbert transform. In this review, we describe a multiscale decomposition technique based on an over-complete dictionary called matching pursuit (MP), and show that it is able to capture both a sharp stimulus-onset transient and a sustained gamma rhythm in local field potential recorded from the primary visual cortex. We compare the performance of MP with other techniques and discuss its advantages and limitations. Data and codes for generating all time-frequency power spectra are provided. PMID:27013668

  12. Comparison of Matching Pursuit Algorithm with Other Signal Processing Techniques for Computation of the Time-Frequency Power Spectrum of Brain Signals

    Science.gov (United States)

    Chandran KS, Subhash; Mishra, Ashutosh; Shirhatti, Vinay

    2016-01-01

    Signals recorded from the brain often show rhythmic patterns at different frequencies, which are tightly coupled to the external stimuli as well as the internal state of the subject. In addition, these signals have very transient structures related to spiking or sudden onset of a stimulus, which have durations not exceeding tens of milliseconds. Further, brain signals are highly nonstationary because both behavioral state and external stimuli can change on a short time scale. It is therefore essential to study brain signals using techniques that can represent both rhythmic and transient components of the signal, something not always possible using standard signal processing techniques such as short time fourier transform, multitaper method, wavelet transform, or Hilbert transform. In this review, we describe a multiscale decomposition technique based on an over-complete dictionary called matching pursuit (MP), and show that it is able to capture both a sharp stimulus-onset transient and a sustained gamma rhythm in local field potential recorded from the primary visual cortex. We compare the performance of MP with other techniques and discuss its advantages and limitations. Data and codes for generating all time-frequency power spectra are provided. PMID:27013668

  13. Brain connectivity analysis from EEG signals using stable phase-synchronized states during face perception tasks

    Science.gov (United States)

    Jamal, Wasifa; Das, Saptarshi; Maharatna, Koushik; Pan, Indranil; Kuyucu, Doga

    2015-09-01

    Degree of phase synchronization between different Electroencephalogram (EEG) channels is known to be the manifestation of the underlying mechanism of information coupling between different brain regions. In this paper, we apply a continuous wavelet transform (CWT) based analysis technique on EEG data, captured during face perception tasks, to explore the temporal evolution of phase synchronization, from the onset of a stimulus. Our explorations show that there exists a small set (typically 3-5) of unique synchronized patterns or synchrostates, each of which are stable of the order of milliseconds. Particularly, in the beta (β) band, which has been reported to be associated with visual processing task, the number of such stable states has been found to be three consistently. During processing of the stimulus, the switching between these states occurs abruptly but the switching characteristic follows a well-behaved and repeatable sequence. This is observed in a single subject analysis as well as a multiple-subject group-analysis in adults during face perception. We also show that although these patterns remain topographically similar for the general category of face perception task, the sequence of their occurrence and their temporal stability varies markedly between different face perception scenarios (stimuli) indicating toward different dynamical characteristics for information processing, which is stimulus-specific in nature. Subsequently, we translated these stable states into brain complex networks and derived informative network measures for characterizing the degree of segregated processing and information integration in those synchrostates, leading to a new methodology for characterizing information processing in human brain. The proposed methodology of modeling the functional brain connectivity through the synchrostates may be viewed as a new way of quantitative characterization of the cognitive ability of the subject, stimuli and information integration

  14. Neurochemical modulation of repetition suppression and novelty signals in the human brain.

    Science.gov (United States)

    Bunzeck, Nico; Thiel, Christiane

    2016-07-01

    The repeated processing of a sensory stimulus, such as a picture or sound, leads to a decrement in response in neurons that fired to the initial presentation. These effects are well known from single cell recordings in the inferior temporal cortex in monkeys, and functional neuroimaging in humans on large-scale neural activity could show similar effects in extrastriate, frontal and medial temporal lobe (MTL) regions. The role of specific neurotransmitters in repeated processing of information is, however, less clear. In the first part of this article, we will introduce the two concepts of repetition suppression and novelty signals, which is followed by a brief overview of pharmacological neuroimaging in humans. We will then summarize human studies suggesting that gamma-aminobutyric-acid (GABA) and acetylcholine (ACh) play an important role in modulating behavioral priming and associated repetition suppression in extrastriate and frontal brain regions. Finally, we review studies on neural novelty signals in the dopaminergic mesolimbic system, and conclude that dopamine (DA) regulates the temporal aspects of novelty processing and closely relates to long-term memory encoding rather than behavioral priming. As such, this review describes differential roles of GABA, ACh and DA in repeated stimulus processing, and further suggests that repetition suppression and neural novelty signals may not be two sides of the same coin but rather independent processes. PMID:26625882

  15. On the space and time evolution of regular or irregular human heart or brain signals

    Science.gov (United States)

    Tuncay, Ç.

    2009-01-01

    A coupled map is suggested to investigate various spatial or temporal designs in biology: several cells (or tissues) in an organ are considered as connected to each other in terms of some molecular diffusions or electrical potential differences and so on. The biological systems (groups of cells) start from various initial conditions for spatial designs (or initial signals for temporal designs) and they evolve in time in terms of the mentioned interactions (connections) besides some individual feedings. The basic aim of the present contribution is to mimic various empirical data for the heart (in normal, quasi-stable, unstable and post operative physiological conditions) or brain (regular or irregular; for epilepsy) signals. The mentioned empirical data are borrowed from various works in the literature which are cited. The suggested model (to be used besides or instead of the artificial network models) involves simple mathematics and the related software is easy. The results may be considered as in good agreement with the mentioned real signals.

  16. STAT1 signaling modulates HIV-1–induced inflammatory responses and leukocyte transmigration across the blood-brain barrier

    OpenAIRE

    Chaudhuri, Anathbandhu; Yang, Bo; Gendelman, Howard E; Persidsky, Yuri; Kanmogne, Georgette D.

    2008-01-01

    The relationship among neuroinflammation, blood-brain barrier (BBB) dysfunction, and progressive HIV-1 infection as they affect the onset and development of neuroAIDS is incompletely understood. One possible link is signal transducers and activators of transcription (STATs) pathways. These respond to proinflammatory and regulatory factors and could affect neuroinflammatory responses induced from infected cells and disease-affected brain tissue. Our previous works demonstrated that HIV-1 activ...

  17. Contribution of altered signal transduction associated to glutamate receptors in brain to the neurological alterations of hepatic encephalopathy

    Institute of Scientific and Technical Information of China (English)

    Vicente Felipo

    2006-01-01

    Patients with liver disease may present hepatic encephalopathy (HE), a complex neuropsychiatric syndrome covering a wide range of neurological alterations,including cognitive and motor disturbances. HE reduces the quality of life of the patients and is associated with poor prognosis. In the worse cases HE may lead to coma or death.The mechanisms leading to HE which are not well known are being studied using animal models. The neurological alterations in HE are a consequence of impaired cerebral function mainly due to alterations in neurotransmission. We review here some studies indicating that alterations in neurotransmission associated to different types of glutamate receptors are responsible for some of the cognitive and motor alterations present in HE.These studies show that the function of the signal transduction pathway glutamate-nitric oxide-cGMP associated to the NMDA type of glutamate receptors is impaired in brain in vivo in HE animal models as well as in brain of patients died of HE. Activation of NMDA receptors in brain activates this pathway and increases cGMP. In animal models of HE this increase in cGMP induced by activation of NMDA receptors is reduced,which is responsible for the impairment in learning ability in these animal models. Increasing cGMP by pharmacological means restores learning ability in rats with HE and may be a new therapeutic approach to improve cognitive function in patients with HE.However, it is necessary to previously assess the possible secondary effects.Patients with HE may present psychomotor slowing,hypokinesia and bradykinesia. Animal models of HE also show hypolocomotion. It has been shown in rats with HE that hypolocomotion is due to excessive activation of metabotropic glutamate receptors (mGluRs) in substantia nigra pars reticulata. Blocking mGluR1 in this brain area normalizes motor activity in the rats, suggesting that a similar treatment for patients with HE could be useful to treat psychomotor slowing and

  18. Contribution of altered signal transduction associated to glutamate receptors in brain to the neurological alterations of hepatic encephalopathy

    Science.gov (United States)

    Felipo, Vicente

    2006-01-01

    Patients with liver disease may present hepatic enceph-alopathy (HE), a complex neuropsychiatric syndrome covering a wide range of neurological alterations, including cognitive and motor disturbances. HE reduces the quality of life of the patients and is associated with poor prognosis. In the worse cases HE may lead to coma or death. The mechanisms leading to HE which are not well known are being studied using animal models. The neurological alterations in HE are a consequence of impaired cerebral function mainly due to alterations in neurotransmission. We review here some studies indicating that alterations in neurotransmission associated to different types of glutamate receptors are responsible for some of the cognitive and motor alterations present in HE. These studies show that the function of the signal transduction pathway glutamate-nitric oxide-cGMP associated to the NMDA type of glutamate receptors is impaired in brain in vivo in HE animal models as well as in brain of patients died of HE. Activation of NMDA receptors in brain activates this pathway and increases cGMP. In animal models of HE this increase in cGMP induced by activation of NMDA receptors is reduced, which is responsible for the impairment in learning ability in these animal models. Increasing cGMP by pharmacological means restores learning ability in rats with HE and may be a new therapeutic approach to improve cognitive function in patients with HE. However, it is necessary to previously assess the possible secondary effects. Patients with HE may present psychomotor slowing, hypokinesia and bradykinesia. Animal models of HE also show hypolocomotion. It has been shown in rats with HE that hypolocomotion is due to excessive activation of metabotropic glutamate receptors (mGluRs) in substantia nigra pars reticulata. Blocking mGluR1 in this brain area normalizes motor activity in the rats, suggesting that a similar treatment for patients with HE could be useful to treat psychomotor slowing and

  19. Performance Analysis of a Hardware Implemented Complex Signal Kurtosis Radio-Frequency Interference Detector

    Science.gov (United States)

    Schoenwald, Adam J.; Bradley, Damon C.; Mohammed, Priscilla N.; Piepmeier, Jeffrey R.; Wong, Mark

    2016-01-01

    In the field of microwave radiometry, Radio Frequency Interference (RFI) consistently degrades the value of scientific results. Through the use of digital receivers and signal processing, the effects of RFI on scientific measurements can be reduced depending on certain circumstances. As technology allows us to implement wider band digital receivers for radiometry, the problem of RFI mitigation changes. Our work focuses on finding a detector that outperforms real kurtosis in wide band scenarios. The algorithm implemented is a complex signal kurtosis detector which was modeled and simulated. The performance of both complex and real signal kurtosis is evaluated for continuous wave, pulsed continuous wave, and wide band quadrature phase shift keying (QPSK) modulations. The use of complex signal kurtosis increased the detectability of interference.

  20. Analysis of signal transduction in brain cells using molecular signal microscope; Bunshi jiho kenbikyo wo mochiita nousaibou no joho henkan kiko no kaiseki

    Energy Technology Data Exchange (ETDEWEB)

    Kawato, Suguru [The University of Tokyo, Tokyo (Japan). Dept. of Biophysics and Life Sciences

    1999-12-16

    We analyzed the signal transduction in brain neurons by real-time imaging of Ca/NO signals using the Molecular Signal Microscope. We also analyzed synthesis and action of neurosteroids in the hippocampus. We discovered steroid synthesis machinery containing cytochrome P 450 scc in hippocampal neurons. We found that pregnenolone sulfate acutely potentiated NMDA receptor-mediated Ca conductivity in hippocampal neurons. We also found that stress steroid corticosterone acutely prolonged NMDA receptor-mediated Ca{sup 2+} influx, resulting in Ca-induced neuro-toxicity. (author)

  1. Nine-month follow-up of the insulin receptor signalling cascade in the brain of streptozotocin rat model of sporadic Alzheimer's disease

    OpenAIRE

    Osmanović Barilar, Jelena; Knezović, Ana; Grünblatt, Edna; Riederer, Peter; Šalković-Petrišić, Melita

    2015-01-01

    Sporadic Alzheimer disease (sAD) is associated with impairment of insulin receptor (IR) signalling in the brain. Rats used to model sAD develop insulin-resistant brain state following intracerebroventricular treatment with a betacytotoxic drug streptozotocin (STZ-icv). Brain IR signalling has been explored usually at only one time point in periods ≤3 months after the STZ-icv administration. We have investigated insulin signalling in the rat hippocampus at five time points in periods ≤9 months...

  2. Reiteration of Hankel singular value decomposition for modeling of complex-valued signal

    Science.gov (United States)

    Staniszewski, Michał; Skorupa, Agnieszka; Boguszewicz, Łukasz; Wicher, Magdalena; Konopka, Marek; Sokół, Maria; Polański, Andrzej

    2016-06-01

    Modeling signal which forms complex values is a common scientific problem, which is present in many applications, i.e. in medical signals, computer graphics and vision. One of the possible solution is utilization of Hankel Singular Value Decomposition. In the first step complex-valued signal is arranged in a special form called Hankel matrix, which is in the next step decomposed in operation of Singular Value Decomposition. Obtained matrices can be then reformulated in order to get parameters describing system. Basic method can be applied for fitting whole signal but it fails in modeling each particular component of signal. Modification of basic HSVD method, which relies on reiteration and is used for main components, and application of prior knowledge solves presented problem.

  3. Inhibitory effects of matrine on electrical signals and amino acid neurotransmitters in hippocampal brain slices

    Institute of Scientific and Technical Information of China (English)

    Xuping Wang; Jiping Chen; Guizhi Zhao; Dan Shou; Xuezhi Hong; Jianmin Zhang

    2009-01-01

    BACKGROUND: Studies on electrical signals of hippocampal brain slices in vivo have shown that matrine inhibits benzylpenicillin sodium-induced activation of neuronal signal transduction.OBJECTIVE: To verify the inhibition effect of matrine on activation of electrical signals in rat brain slices and the role matrine plays in hippocampal amino acid transmitter release.DESIGN, TIME AND SETTING: The in vitro, neurophysiological, controlled experiment was performed in the Zhejiang Province Key Laboratory of Cardio-cerebrovascular Disease and Nerve System Drugs Appraisement and Chinese Traditional Medicine Screening and Research between July 2003 and May 2004. The in vivo, neuronal, biochemical experiment was performed in the Zhejiang Province Key Laboratory of Chinese Traditional Medicine Quality Standardization from July 2005 to December 2006.MATERIALS: Forty healthy, Sprague Dawley rats, 7-8 weeks old, and 120 healthy, ICR mice, 5-6weeks old, were included in this study, irrespective of gender. Matrine powder was provided by the National Institute for the Control of Pharmaceutical and Biological Products, China. Matrine injection was purchased from Zhuhai Biochemical Pharmaceutical Factory, China. Penicillin was bought from Shijiazhuang Pharmaceutical Group Co., Ltd., China.METHODS: (1) Rats were randomly assigned to four groups: control, penicillin model, and matrine high-dose and low-dose, with 10 rats in each group. The control group was perfused with artificial cerebrospinal fluid, in the remaining three groups, hippocampal brain slices were perfused with normal artificial cerebrospinal fluid containing 1x106 U/L penicillin for the first 10 minutes. The penicillin model group received artificial cerebrospinal fluid for an additional 30 minutes, while the matrine high-dose and low-dose groups received 0.1 g/L and 0.05 g/L matdne, respectively, for an additional 30 minutes. (2) Mice were randomly assigned to four groups (n=30). The matrine high-,medium-, and low

  4. A new NOE-mediated MT signal at around -1.6ppm for detecting ischemic stroke in rat brain.

    Science.gov (United States)

    Zhang, Xiao-Yong; Wang, Feng; Afzal, Aqeela; Xu, Junzhong; Gore, John C; Gochberg, Daniel F; Zu, Zhongliang

    2016-10-01

    In the present work, we reported a new nuclear Overhauser enhancement (NOE)-mediated magnetization transfer (MT) signal at around -1.6ppm (NOE(-1.6)) in rat brain and investigated its application in the detection of acute ischemic stroke in rodent model. Using continuous wave (CW) MT sequence, the NOE(-1.6) is reliably detected in rat brain. The amplitude of this new NOE signal in rat brain was quantified using a 5-pool Lorentzian Z-spectral fitting method. Amplitudes of amide, amine, NOE at -3.5ppm (NOE(-3.5)), as well as NOE(-1.6) were mapped using this fitting method in rat brain. Several other conventional imaging parameters (R1, R2, apparent diffusion coefficient (ADC), and semi-solid pool size ratio (PSR)) were also measured. Our results show that NOE(-1.6), R1, R2, ADC, and APT signals from stroke lesion have significant changes at 0.5-1h after stroke. Compared with several other imaging parameters, NOE(-1.6) shows the strongest contrast differences between stroke and contralateral normal tissues and stays consistent over time until 2h after onset of stroke. Our results demonstrate that this new NOE(-1.6) signal in rat brain is a new potential contrast for assessment of acute stroke in vivo and might provide broad applications in the detection of other abnormal tissues. PMID:27211260

  5. Effects of tramadol, clonazepam, and their combination on brain mitochondrial complexes.

    Science.gov (United States)

    Mohamed, Tarek Mostafa; Ghaffar, Hamdy M Abdel; El Husseiny, Rabee M R

    2015-12-01

    The present study is an unsubstantiated qualitative assessment of the abused drugs-tramadol and clonazepam. The aim of this study is to evaluate whether the effects of tramadol, clonazepam, and their combination on mitochondrial electron transport chain (ETC) complexes were influential at therapeutic or at progressively increasing doses. The study comprised of a total of 70 healthy male rats, aged 3 months. According to the drug intake regimen, animals were divided into seven groups: control, tramadol therapeutic, clonazepam therapeutic, combination therapeutic, tramadol abuse, clonazepam abuse, and combination abuse group. At the end of the experiment, brain mitochondrial ETC complexes (I, II, III, and IV) were evaluated. Histopathological examinations were also performed on brain tissues. The results showed that groups that received tramadol (therapeutic and abuse) suffered from weight loss. Tramadol abuse group and combination abuse group showed significant decrease in the activities of I, III, and IV complexes but not in the activity of complex II. In conclusion, tramadol but not clonazepam has been found to partially inhibit the activities of respiratory chain complexes I, III, and IV but not the activity of complex II and such inhibition occurred only at doses that exceeded the maximum recommended adult human daily therapeutic doses. This result explains the clinical and histopathological effects of tramadol, such as seizures and red neurons (marker for apoptosis), respectively. PMID:23843224

  6. Neutron capture therapy signal-to-noise ratio distribution for deep seated brain tumors

    International Nuclear Information System (INIS)

    Boron and Gadolinium Neutron Capture Therapy effects are modelled using COG, a Monte Carlo radiation transport code developed and tested at Lawrence Livermore National Laboratory (LLNL) and MCNP. Calculations were performed to analyze the effect of various gadolinium concentrations on dose distribution and cell-kill effect of the GdNCT modality and to determine the optimum therapeutic conditions for treating the brain cancers. Results showed that a concentration of 100 ppm gadolinium, resulting in a signal-to-noise ratio of 1.53, was most beneficial for a deep seated tumor irradiated with an epithermal beam. A concentration of 1000 ppm, producing a ratio of 1.41, may still be advantageous, as the dose is increased without compromising the tumor to normal tissue dose ratio. The ratio decreases substantially to 1.15 for a concentration of 5000 ppm, suggesting such a high concentration may be deleterious. Calculations were also done for alternate tumor locations. (author)

  7. Getting a decent (but sparse) signal to the brain for users of cochlear implants.

    Science.gov (United States)

    Wilson, Blake S

    2015-04-01

    The challenge in getting a decent signal to the brain for users of cochlear implants (CIs) is described. A breakthrough occurred in 1989 that later enabled most users to understand conversational speech with their restored hearing alone. Subsequent developments included stimulation in addition to that provided with a unilateral CI, either with electrical stimulation on both sides or with acoustic stimulation in combination with a unilateral CI, the latter for persons with residual hearing at low frequencies in either or both ears. Both types of adjunctive stimulation produced further improvements in performance for substantial fractions of patients. Today, the CI and related hearing prostheses are the standard of care for profoundly deaf persons and ever-increasing indications are now allowing persons with less severe losses to benefit from these marvelous technologies. The steps in achieving the present levels of performance are traced, and some possibilities for further improvements are mentioned. This article is part of a Special Issue entitled . PMID:25500178

  8. Direct Signaling from Astrocytes to Neurons in Cultures of Mammalian Brain Cells

    Science.gov (United States)

    Nedergaard, Maiken

    1994-03-01

    Although astrocytes have been considered to be supportive, rather than transmissive, in the adult nervous system, recent studies have challenged this assumption by demonstrating that astrocytes possess functional neurotransmitter receptors. Astrocytes are now shown to directly modulate the free cytosolic calcium, and hence transmission characteristics, of neighboring neurons. When a focal electric field potential was applied to single astrocytes in mixed cultures of rat forebrain astrocytes and neurons, a prompt elevation of calcium occurred in the target cell. This in turn triggered a wave of calcium increase, which propagated from astrocyte to astrocyte. Neurons resting on these astrocytes responded with large increases in their concentration of cytosolic calcium. The gap junction blocker octanol attenuated the neuronal response, which suggests that the astrocytic-neuronal signaling is mediated through intercellular connections rather than synaptically. This neuronal response to local astrocytic stimulation may mediate local intercellular communication within the brain.

  9. Cis-regulatory architecture of a brain signaling center predates the origin of chordates.

    Science.gov (United States)

    Yao, Yao; Minor, Paul J; Zhao, Ying-Tao; Jeong, Yongsu; Pani, Ariel M; King, Anna N; Symmons, Orsolya; Gan, Lin; Cardoso, Wellington V; Spitz, François; Lowe, Christopher J; Epstein, Douglas J

    2016-05-01

    Genomic approaches have predicted hundreds of thousands of tissue-specific cis-regulatory sequences, but the determinants critical to their function and evolutionary history are mostly unknown. Here we systematically decode a set of brain enhancers active in the zona limitans intrathalamica (zli), a signaling center essential for vertebrate forebrain development via the secreted morphogen Sonic hedgehog (Shh). We apply a de novo motif analysis tool to identify six position-independent sequence motifs together with their cognate transcription factors that are essential for zli enhancer activity and Shh expression in the mouse embryo. Using knowledge of this regulatory lexicon, we discover new Shh zli enhancers in mice and a functionally equivalent element in hemichordates, indicating an ancient origin of the Shh zli regulatory network that predates the chordate phylum. These findings support a strategy for delineating functionally conserved enhancers in the absence of overt sequence homologies and over extensive evolutionary distances. PMID:27064252

  10. TNF signaling inhibition in the CNS: implications for normal brain function and neurodegenerative disease

    Directory of Open Access Journals (Sweden)

    Tansey Malú G

    2008-10-01

    Full Text Available Abstract The role of tumor necrosis factor (TNF as an immune mediator has long been appreciated but its function in the brain is still unclear. TNF receptor 1 (TNFR1 is expressed in most cell types, and can be activated by binding of either soluble TNF (solTNF or transmembrane TNF (tmTNF, with a preference for solTNF; whereas TNFR2 is expressed primarily by microglia and endothelial cells and is preferentially activated by tmTNF. Elevation of solTNF is a hallmark of acute and chronic neuroinflammation as well as a number of neurodegenerative conditions including ischemic stroke, Alzheimer's (AD, Parkinson's (PD, amyotrophic lateral sclerosis (ALS, and multiple sclerosis (MS. The presence of this potent inflammatory factor at sites of injury implicates it as a mediator of neuronal damage and disease pathogenesis, making TNF an attractive target for therapeutic development to treat acute and chronic neurodegenerative conditions. However, new and old observations from animal models and clinical trials reviewed here suggest solTNF and tmTNF exert different functions under normal and pathological conditions in the CNS. A potential role for TNF in synaptic scaling and hippocampal neurogenesis demonstrated by recent studies suggest additional in-depth mechanistic studies are warranted to delineate the distinct functions of the two TNF ligands in different parts of the brain prior to large-scale development of anti-TNF therapies in the CNS. If inactivation of TNF-dependent inflammation in the brain is warranted by additional pre-clinical studies, selective targeting of TNFR1-mediated signaling while sparing TNFR2 activation may lessen adverse effects of anti-TNF therapies in the CNS.

  11. Dysregulated brain immunity and neurotrophin signaling in Rett syndrome and autism spectrum disorders.

    Science.gov (United States)

    Theoharides, Theoharis C; Athanassiou, Marianna; Panagiotidou, Smaro; Doyle, Robert

    2015-02-15

    Rett syndrome is a neurodevelopmental disorder, which occurs in about 1:15,000 females and presents with neurologic and communication defects. It is transmitted as an X-linked dominant linked to mutations of the methyl-CpG-binding protein (MeCP2), a gene transcription suppressor, but its definitive pathogenesis is unknown thus hindering development of effective treatments. Almost half of children with Rett syndrome also have behavioral symptoms consistent with those of autism spectrum disorders (ASDs). PubMed was searched (2005-2014) using the terms: allergy, atopy, brain, brain-derived neurotrophic factor (BDNF), corticotropin-releasing hormone (CRH), cytokines, gene mutations, inflammation, mast cells (MCs), microglia, mitochondria, neurotensin (NT), neurotrophins, seizures, stress, and treatment. There are a number of intriguing differences and similarities between Rett syndrome and ASDs. Rett syndrome occurs in females, while ASDs more often in males, and the former has neurologic disabilities unlike ASDs. There is evidence of dysregulated immune system early in life in both conditions. Lack of microglial phagocytosis and decreased levels of BDNF appear to distinguish Rett syndrome from ASDs, in which there is instead microglia activation and/or proliferation and possibly defective BDNF signaling. Moreover, brain mast cell (MC) activation and focal inflammation may be more prominent in ASDs than Rett syndrome. The flavonoid luteolin blocks microglia and MC activation, provides BDNF-like activity, reverses Rett phenotype in mouse models, and has a significant benefit in children with ASDs. Appropriate formulations of luteolin or other natural molecules may be useful in the treatment of Rett syndrome. PMID:25669997

  12. Uncoupling of the endocannabinoid signalling complex in a mouse model of fragile X syndrome

    OpenAIRE

    Jung, Kwang-Mook; Sepers, Marja; Henstridge, Christopher M.; Lassalle, Olivier; Neuhofer, Daniela; Martin, Henry; Ginger, Melanie; Frick, Andreas; DiPatrizio, Nicholas V.; Mackie, Ken; Katona, Istvan; Piomelli, Daniele; Manzoni, Olivier J.

    2012-01-01

    Fragile X syndrome, the most commonly known genetic cause of autism, is due to loss of the fragile X mental retardation protein, which regulates signal transduction at metabotropic glutamate receptor-5 in the brain. Fragile X mental retardation protein deletion in mice enhances metabotropic glutamate receptor-5-dependent long-term depression in the hippocampus and cerebellum. Here we show that a distinct type of metabotropic glutamate receptor-5-dependent long-term depression at excitatory sy...

  13. Dietary Lipids Inform the Gut and Brain about Meal Arrival via CD36-Mediated Signal Transduction.

    Science.gov (United States)

    Sundaresan, Sinju; Abumrad, Nada A

    2015-10-01

    Sensing mechanisms for nutrients, in particular dietary fat, operate in the mouth, brain, and gastrointestinal tract and play a key role in regulating feeding behavior and energy balance. Critical to these regulatory mechanisms are the specialized receptors present on taste buds on the tongue, on neurons in specialized centers in the brain, and on epithelial and enteroendocrine cells in the intestinal mucosa. These receptors recognize nutrients and respond by inducing intracellular signals that trigger release of bioactive compounds that influence other organs and help coordinate the response to the meal. Components of dietary fat that are recognized by these receptors are the long-chain fatty acids that act as ligands for 2 G protein-coupled receptors, GPR40 and GPR120, and the fatty acid (FA) translocase/CD36. Recent evidence that emphasizes the important role of CD36 in orosensory, intestinal, and neuronal sensing of FAs under physiologic conditions is highlighted in the review. How this role intersects with that of GPR120 and GPR40 in the regulation of food preference and energy balance is briefly discussed. PMID:26269236

  14. Brain-derived neurotrophic factor signaling is altered in the forebrain of Engrailed-2 knockout mice.

    Science.gov (United States)

    Zunino, G; Messina, A; Sgadò, P; Baj, G; Casarosa, S; Bozzi, Y

    2016-06-01

    Engrailed-2 (En2), a homeodomain transcription factor involved in regionalization and patterning of the midbrain and hindbrain regions has been associated to autism spectrum disorders (ASDs). En2 knockout (En2(-/-)) mice show ASD-like features accompanied by a significant loss of GABAergic subpopulations in the hippocampus and neocortex. Brain-derived neurotrophic factor (BDNF) is a crucial factor for the postnatal development of forebrain GABAergic neurons, and altered GABA signaling has been hypothesized to underlie the symptoms of ASD. Here we sought to determine whether interneuron loss in the En2(-/-) forebrain might be related to altered expression of BDNF and its signaling receptors. We first evaluated the expression of different BDNF mRNA isoforms in the neocortex and hippocampus of wild-type (WT) and En2(-/-) mice. Quantitative RT-PCR showed a marked down-regulation of several splicing variants of BDNF mRNA in the neocortex but not hippocampus of adult En2(-/-) mice, as compared to WT controls. Accordingly, levels of mature BDNF protein were lower in the neocortex but not hippocampus of En2(-/-) mice, as compared to WT. Increased levels of phosphorylated TrkB and decreased levels of p75 receptor were also detected in the neocortex of mutant mice. Accordingly, the expression of low density lipoprotein receptor (LDLR) and RhoA, two genes regulated via p75 was significantly altered in forebrain areas of mutant mice. These data indicate that BDNF signaling alterations might be involved in the anatomical changes observed in the En2(-/-) forebrain and suggest a pathogenic role of altered BDNF signaling in this mouse model of ASD. PMID:26987954

  15. Affordable low complexity heart/brain monitoring methodology for remote health care.

    Science.gov (United States)

    Vemishetty, Naresh; Jadhav, Pranit; Adapa, Bhagyaraja; Acharyya, Amit; Pachamuthu, Rajalakshmi; Naik, Ganesh R

    2015-01-01

    This paper introduces a dual-mode low complex on-chip methodology for processing of ECG (Electrocardiogram) and EEG (Electroencephalography) signals, wherein based on the input switch the architecture can be dynamically configured to operate either as an ECG bio-marker or EEG signal de-noising system. In both the modes the signal processing technique depends on the output of the DWT (Discrete Wavelet Transform), hence a low complex methodology has been developed in which both ECG and EEG processing blocks sharing the same DWT block resulting in low area and low power consumption. The integrated ECG and EEG methodology has been implemented in Matlab, for verifying the ECG processing block the ECG database is taken from MIT-BIH PTBDB and IITH DB, similarly for EEG processing block the EEG signals are taken from PhysioNet database. The outcome of methodology in Matlab is equal to the results obtained from individual ECG and EEG blocks. PMID:26737434

  16. A simple iterative independent component analysis algorithm for vibration source signal identification of complex structures

    Directory of Open Access Journals (Sweden)

    Lee Dong-Sup

    2015-01-01

    Full Text Available Independent Component Analysis (ICA, one of the blind source separation methods, can be applied for extracting unknown source signals only from received signals. This is accomplished by finding statistical independence of signal mixtures and has been successfully applied to myriad fields such as medical science, image processing, and numerous others. Nevertheless, there are inherent problems that have been reported when using this technique: instability and invalid ordering of separated signals, particularly when using a conventional ICA technique in vibratory source signal identification of complex structures. In this study, a simple iterative algorithm of the conventional ICA has been proposed to mitigate these problems. The proposed method to extract more stable source signals having valid order includes an iterative and reordering process of extracted mixing matrix to reconstruct finally converged source signals, referring to the magnitudes of correlation coefficients between the intermediately separated signals and the signals measured on or nearby sources. In order to review the problems of the conventional ICA technique and to validate the proposed method, numerical analyses have been carried out for a virtual response model and a 30 m class submarine model. Moreover, in order to investigate applicability of the proposed method to real problem of complex structure, an experiment has been carried out for a scaled submarine mockup. The results show that the proposed method could resolve the inherent problems of a conventional ICA technique.

  17. Nicotine and elevated body temperature reduce the complexity of the genioglossus and diaphragm EMG signals in rats during early maturation

    Science.gov (United States)

    Akkurt, David; Akay, Yasemin M.; Akay, Metin

    2009-10-01

    In this paper, we examined the effect of nicotine exposure and increased body temperature on the complexity (dynamics) of the genioglossus muscle (EMGg) and the diaphragm muscle (EMGdia) to explore the effects of nicotine and hyperthermia. Nonlinear dynamical analysis of the EMGdia and EMGg signals was performed using the approximate entropy method on 15 (7 saline- and 8 nicotine-treated) juvenile rats (P25-P35) and 19 (11 saline- and 8 nicotine-treated) young adult rats (P36-P44). The mean complexity values were calculated over the ten consecutive breaths using the approximate entropy method during mild elevated body temperature (38 °C) and severe elevated body temperature (39-40 °C) in two groups. In the first (nicotine) group, rats were treated with single injections of nicotine enough to produce brain levels of nicotine similar to those achieved in human smokers (2.5 (mg kg-1)/day) until the recording day. In the second (control) group, rats were treated with injections of saline, beginning at postnatal 5 days until the recording day. Our results show that warming the rat by 2-3 °C and nicotine exposure significantly decreased the complexity of the EMGdia and EMGg for the juvenile age group. This reduction in the complexity of the EMGdia and EMGg for the nicotine group was much greater than the normal during elevated body temperatures. We speculate that the generalized depressive effects of nicotine exposure and elevated body temperature on the respiratory neural firing rate and the behavior of the central respiratory network could be responsible for the drastic decrease in the complexity of the EMGdia and EMGg signals, the outputs of the respiratory neural network during early maturation.

  18. Neural changes in the primate brain correlated with the evolution of complex motor skills.

    Science.gov (United States)

    Yamazaki, Y; Hikishima, K; Saiki, M; Inada, M; Sasaki, E; Lemon, R N; Price, C J; Okano, H; Iriki, A

    2016-01-01

    Complex motor skills of eventual benefit can be learned after considerable trial and error. What do structural brain changes that accompany such effortful long-term learning tell us about the mechanisms for developing innovative behavior? Using MRI, we monitored brain structure before, during and after four marmosets learnt to use a rake, over a long period of 10-13 months. Throughout learning, improvements in dexterity and visuo-motor co-ordination correlated with increased volume in the lateral extrastriate cortex. During late learning, when the most complex behavior was maintained by sustained motivation to acquire the skill, the volume of the nucleus accumbens increased. These findings reflect the motivational state required to learn, and show accelerated function in higher visual cortex that is consistent with neurocognitive divergence across a spectrum of primate species. PMID:27498966

  19. Forget-me-not:Complex floral displays,inter-signal interactions,and pollinator cognition

    Institute of Scientific and Technical Information of China (English)

    Anne S.LEONARD; Anna DORNHAUS; Daniel R.PAPAJ

    2011-01-01

    Flowers are multisensory displays used by plants to influence the behavior of pollinators.Although we know a great deal about how individual signal components are preduced by plants and detected or learned by pollinators,very few experiments directly address the function of floral signal complexity,I.e.how the multicompenent nature of these signals benefits plant or pollinator.Yet,experimental psychology suggests that increasing complexity can enhance subjects'ability to deteCt,learn and remember stimuli,and the plant,sreproductive success depends upon ensuring that pollinators learn their signals and so transport pollen to other similar(conspecific)flowers.Here we explore functional hypotheses for why plants invest in complex floral displays focusing on hypotheses in which floral signals interact to promote pollinator learning and memory'Specifically,we discuss how an attention-altering or context-providing function of one signal may promote acquisition or recall of a second signal.Although we focus on communication between plants and poilinators,these process-based hypotheses should apply to any situation where a sender benefits from enhancing a receiver's acquisition or recall of informtion.

  20. A Measure for Brain Complexity: Relating Functional Segregation and Integration in the Nervous System

    Science.gov (United States)

    Tononi, Giulio; Sporns, Olaf; Edelman, Gerald M.

    1994-05-01

    In brains of higher vertebrates, the functional segregation of local areas that differ in their anatomy and physiology contrasts sharply with their global integration during perception and behavior. In this paper, we introduce a measure, called neural complexity (C_N), that captures the interplay between these two fundamental aspects of brain organization. We express functional segregation within a neural system in terms of the relative statistical independence of small subsets of the system and functional integration in terms of significant deviations from independence of large subsets. C_N is then obtained from estimates of the average deviation from statistical independence for subsets of increasing size. C_N is shown to be high when functional segregation coexists with integration and to be low when the components of a system are either completely independent (segregated) or completely dependent (integrated). We apply this complexity measure in computer simulations of cortical areas to examine how some basic principles of neuroanatomical organization constrain brain dynamics. We show that the connectivity patterns of the cerebral cortex, such as a high density of connections, strong local connectivity organizing cells into neuronal groups, patchiness in the connectivity among neuronal groups, and prevalent reciprocal connections, are associated with high values of C_N. The approach outlined here may prove useful in analyzing complexity in other biological domains such as gene regulation and embryogenesis.

  1. Wnt signaling through inhibition of β-catenin degradation in an intact Axin1 complex.

    Science.gov (United States)

    Li, Vivian S W; Ng, Ser Sue; Boersema, Paul J; Low, Teck Y; Karthaus, Wouter R; Gerlach, Jan P; Mohammed, Shabaz; Heck, Albert J R; Maurice, Madelon M; Mahmoudi, Tokameh; Clevers, Hans

    2012-06-01

    Degradation of cytosolic β-catenin by the APC/Axin1 destruction complex represents the key regulated step of the Wnt pathway. It is incompletely understood how the Axin1 complex exerts its Wnt-regulated function. Here, we examine the mechanism of Wnt signaling under endogenous levels of the Axin1 complex. Our results demonstrate that β-catenin is not only phosphorylated inside the Axin1 complex, but also ubiquinated and degraded via the proteasome, all within an intact Axin1 complex. In disagreement with current views, we find neither a disassembly of the complex nor an inhibition of phosphorylation of Axin1-bound β-catenin upon Wnt signaling. Similar observations are made in primary intestinal epithelium and in colorectal cancer cell lines carrying activating Wnt pathway mutations. Wnt signaling suppresses β-catenin ubiquitination normally occurring within the complex, leading to complex saturation by accumulated phospho-β-catenin. Subsequently, newly synthesized β-catenin can accumulate in a free cytosolic form and engage nuclear TCF transcription factors. PMID:22682247

  2. Simulation study on effects of signaling network structure on the developmental increase in complexity

    Energy Technology Data Exchange (ETDEWEB)

    Keranen, Soile V.E.

    2003-04-02

    The developmental increase in structural complexity in multicellular life forms depends on local, often non-periodic differences in gene expression. These depend on a network of gene-gene interactions coded within the organismal genome. To better understand how genomic information generates complex expression patterns, I have modeled the pattern forming behavior of small artificial genomes in virtual blastoderm embryos. I varied several basic properties of these genomic signaling networks, such as the number of genes, the distributions of positive (inductive) and negative (repressive) interactions, and the strengths of gene-gene interactions, and analyzed their effects on developmental pattern formation. The results show how even simple genomes can generate complex non-periodic patterns under suitable conditions. They also show how the frequency of complex patterns depended on the numbers and relative arrangements of positive and negative interactions. For example, negative co-regulation of signaling pathway components increased the likelihood of (complex) patterns relative to differential negative regulation of the pathway components. Interestingly, neither quantitative differences either in strengths of signaling interactions nor multiple response thresholds to signal concentration (as in morphogen gradients) were essential for formation of multiple, spatially unique cell types. Thus, with combinatorial code of gene regulation and hierarchical signaling interactions, it is theoretically possible to organize metazoan embryogenesis with just a small fraction of the metazoan genome. Because even small networks can generate complex patterns when they contain a suitable set of connections, evolution of metazoan complexity may have depended more on selection for favourable configurations of signaling interactions than on the increase in numbers of regulatory genes.

  3. Glioblastoma multiforme versus solitary supratentorial brain metastasis. Differentiation based on morphology and magnetic resonance signal characteristics

    International Nuclear Information System (INIS)

    Purpose: To evaluate the diagnostic potential of a multi-factor analysis of morphometric parameters and magnetic resonance (MR) signal characteristics of a mass and peritumoral area to distinguish solitary supratentorial metastasis from glioblastoma multiforme (GBM). Materials and Methods: MR examinations of 51 patients with histologically proven GBM and 44 with a single supratentorial metastasis were evaluated. A large variety of morphologic criteria and MR signal characteristics in different sequences were analyzed. The data were subjected to logistic regression to investigate their ability to discriminate between GBM and cerebral metastasis. Receiver-operating characteristic (ROC) analysis was used to select an optimal cut-off point for prediction and to assess the predictive value in terms of sensitivity, specificity, and accuracy of the final model. Results: The logistic regression analysis revealed that the ratio of the maximum diameter of the peritumoral area measured on T2-weighted images (d T2) to the maximum diameter of the enhancing mass area (d T1, post-contrast) is the only useful criterion to distinguish single supratentorial brain metastasis from GBM with a lower ratio favoring GBM (accuracy 68 %, sensitivity 84 % and specificity 45 %). The cut-off point for the ratio d T2/d T1 post-contrast was calculated as 2.35. Conclusion: Measurement of maximum diameters of the peritumoral area in relation to the enhancing mass can be evaluated easily in the clinical routine to discriminate GBM from solitary supratentorial metastasis with an accuracy comparable to that of advanced MRI techniques. (orig.)

  4. Hybrid Brain-Computer Interface (BCI) based on the EEG and EOG signals.

    Science.gov (United States)

    Jiang, Jun; Zhou, Zongtan; Yin, Erwei; Yu, Yang; Hu, Dewen

    2014-01-01

    Recently, the integration of different electrophysiological signals into an electroencephalogram (EEG) has become an effective approach to improve the practicality of brain-computer interface (BCI) systems, referred to as hybrid BCIs. In this paper, a hybrid BCI was designed by combining an EEG with electrocardiograph (EOG) signals and tested using a target selection experiment. Gaze direction from the EOG and the event-related (de)synchronization (ERD/ERS) induced by motor imagery from the EEG were simultaneously detected as the output of the BCI system. The target selection mechanism was based on the synthesis of the gaze direction and ERD activity. When an ERD activity was detected, the target corresponding to the gaze direction was selected; without ERD activity, no target was selected, even when a subjects gaze was directed at the target. With this mechanism, the operation of the BCI system is more flexible and voluntary. The accuracy and completion time of the target selection tasks during the online testing were 89.3% and 2.4 seconds, respectively. These results show the feasibility and practicality of this hybrid BCI system, which can potentially be used in the rehabilitation of disabled individuals. PMID:25226998

  5. Long-term music training tunes how the brain temporally binds signals from multiple senses.

    Science.gov (United States)

    Lee, Hweeling; Noppeney, Uta

    2011-12-20

    Practicing a musical instrument is a rich multisensory experience involving the integration of visual, auditory, and tactile inputs with motor responses. This combined psychophysics-fMRI study used the musician's brain to investigate how sensory-motor experience molds temporal binding of auditory and visual signals. Behaviorally, musicians exhibited a narrower temporal integration window than nonmusicians for music but not for speech. At the neural level, musicians showed increased audiovisual asynchrony responses and effective connectivity selectively for music in a superior temporal sulcus-premotor-cerebellar circuitry. Critically, the premotor asynchrony effects predicted musicians' perceptual sensitivity to audiovisual asynchrony. Our results suggest that piano practicing fine tunes an internal forward model mapping from action plans of piano playing onto visible finger movements and sounds. This internal forward model furnishes more precise estimates of the relative audiovisual timings and hence, stronger prediction error signals specifically for asynchronous music in a premotor-cerebellar circuitry. Our findings show intimate links between action production and audiovisual temporal binding in perception. PMID:22114191

  6. A novel feature extracting method of QRS complex classification for mobile ECG signals

    Science.gov (United States)

    Zhu, Lingyun; Wang, Dong; Huang, Xianying; Wang, Yue

    2007-12-01

    The conventional classification parameters of QRS complex suffer from larger activity rang of patients and lower signal to noise ratio in mobile cardiac telemonitoring system and can not meet the identification needs of ECG signal. Based on individual sinus heart rhythm template built with mobile ECG signals in time window, we present semblance index to extract the classification features of QRS complex precisely and expeditiously. Relative approximation r2 and absolute error r3 are used as estimating parameters of semblance between testing QRS complex and template. The evaluate parameters corresponding to QRS width and types are demonstrated to choose the proper index. The results show that 99.99 percent of the QRS complex for sinus and superventricular ECG signals can be distinguished through r2 but its average accurate ratio is only 46.16%. More than 97.84 percent of QRS complexes are identified using r3 but its accurate ratio to the sinus and superventricular is not better than r2. By the feature parameter of width, only 42.65 percent of QRS complexes are classified correctly, but its accurate ratio to the ventricular is superior to r2. To combine the respective superiority of three parameters, a nonlinear weighing computation of QRS width, r2 and r3 is introduced and the total classification accuracy up to 99.48% by combing indexes.

  7. Mu-Opioid (MOP) receptor mediated G-protein signaling is impaired in specific brain regions in a rat model of schizophrenia.

    Science.gov (United States)

    Szűcs, Edina; Büki, Alexandra; Kékesi, Gabriella; Horváth, Gyöngyi; Benyhe, Sándor

    2016-04-21

    Schizophrenia is a complex mental health disorder. Clinical reports suggest that many patients with schizophrenia are less sensitive to pain than other individuals. Animal models do not interpret schizophrenia completely, but they can model a number of symptoms of the disease, including decreased pain sensitivities and increased pain thresholds of various modalities. Opioid receptors and endogenous opioid peptides have a substantial role in analgesia. In this biochemical study we investigated changes in the signaling properties of the mu-opioid (MOP) receptor in different brain regions, which are involved in the pain transmission, i.e., thalamus, olfactory bulb, prefrontal cortex and hippocampus. Our goal was to compare the transmembrane signaling mediated by MOP receptors in control rats and in a recently developed rat model of schizophrenia. Regulatory G-protein activation via MOP receptors were measured in [(35)S]GTPγS binding assays in the presence of a highly selective MOP receptor peptide agonist, DAMGO. It was found that the MOP receptor mediated activation of G-proteins was substantially lower in membranes prepared from the 'schizophrenic' model rats than in control animals. The potency of DAMGO to activate MOP receptor was also decreased in all brain regions studied. Taken together in our rat model of schizophrenia, MOP receptor mediated G-proteins have a reduced stimulatory activity compared to membrane preparations taken from control animals. The observed distinct changes of opioid receptor functions in different areas of the brain do not explain the augmented nociceptive threshold described in these animals. PMID:26946106

  8. EXPRESSION OF SV40 Tag AND FORMATION Tag-p53 AND Tag-Rb COMPLEXES IN CHINESE BRAIN TUMORS

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective: To investigate the expression of SV40 Tag andformation of Tag-p53 and Tag-Rb complexes in Chinese brain tumors. Methods: SV40 large tumor antigen (Tag) were investigated by immunoprecipitation, silver staining and Western blot in 65 cases of Chinese brain tumors and 8 cases of normal brain tissues. Tag-p53 and Tag-Rb complexes were screened by the same way in 20 and 15 Tag positive tumor tissues respectively. Results: Tag was found in all of 8 ependymomas and 2 choroid plexus papillomas, 90% (9/10) of pituitary adenomas, 73% (11/15) of astrocytomas, 70% (7/10) of meningiomas, 50% (4/8) of glioblastoma multiform, 33% (2/6) of medulloblastomas, 5 oligodendrogliomas, 1 pineocytoma and 8 normal brain tissues were negative for Tag. Tag-p53 complex was detected in all of 20 Tag positive tumors as well as Tag-Rb complex in all of 15 Tag positive tumors. Conclusion: SV40 Tag is not only expressed in human brain tumors, but also it can form specific complexes with tumor suppressors p53 and Rb. SV40 is correlated to human brain tumorigenesis. The inactivation of p53 and Rb due to the formation of Tag-p53 and Tag-Rb complexes is possibly an important mechanism in the etiopathogenesis of human brain tumors.

  9. Performance Analysis of a Hardware Implemented Complex Signal Kurtosis Radio-Frequency Interference Detector

    Science.gov (United States)

    Schoenwald, Adam J.; Bradley, Damon C.; Mohammed, Priscilla N.; Piepmeier, Jeffrey R.; Wong, Mark

    2016-01-01

    Radio-frequency interference (RFI) is a known problem for passive remote sensing as evidenced in the L-band radiometers SMOS, Aquarius and more recently, SMAP. Various algorithms have been developed and implemented on SMAP to improve science measurements. This was achieved by the use of a digital microwave radiometer. RFI mitigation becomes more challenging for microwave radiometers operating at higher frequencies in shared allocations. At higher frequencies larger bandwidths are also desirable for lower measurement noise further adding to processing challenges. This work focuses on finding improved RFI mitigation techniques that will be effective at additional frequencies and at higher bandwidths. To aid the development and testing of applicable detection and mitigation techniques, a wide-band RFI algorithm testing environment has been developed using the Reconfigurable Open Architecture Computing Hardware System (ROACH) built by the Collaboration for Astronomy Signal Processing and Electronics Research (CASPER) Group. The testing environment also consists of various test equipment used to reproduce typical signals that a radiometer may see including those with and without RFI. The testing environment permits quick evaluations of RFI mitigation algorithms as well as show that they are implementable in hardware. The algorithm implemented is a complex signal kurtosis detector which was modeled and simulated. The complex signal kurtosis detector showed improved performance over the real kurtosis detector under certain conditions. The real kurtosis is implemented on SMAP at 24 MHz bandwidth. The complex signal kurtosis algorithm was then implemented in hardware at 200 MHz bandwidth using the ROACH. In this work, performance of the complex signal kurtosis and the real signal kurtosis are compared. Performance evaluations and comparisons in both simulation as well as experimental hardware implementations were done with the use of receiver operating characteristic (ROC

  10. Wnt signalling induces accumulation of phosphorylated β-catenin in two distinct cytosolic complexes.

    Science.gov (United States)

    Gerlach, Jan P; Emmink, Benjamin L; Nojima, Hisashi; Kranenburg, Onno; Maurice, Madelon M

    2014-11-01

    Wnt/β-catenin signalling controls development and adult tissue homeostasis and causes cancer when inappropriately activated. In unstimulated cells, an Axin1-centred multi-protein complex phosphorylates the transcriptional co-activator β-catenin, marking it for degradation. Wnt signalling antagonizes β-catenin proteolysis, leading to its accumulation and target gene expression. How Wnt stimulation alters the size distribution, composition and activity of endogenous Axin1 complexes remains poorly understood. Here, we employed two-dimensional blue native/SDS-PAGE to analyse endogenous Axin1 and β-catenin complexes during Wnt signalling. We show that the size range of Axin1 complexes is conserved between species and remains largely unaffected by Wnt stimulation. We detect a striking Wnt-dependent, cytosolic accumulation of both non-phosphorylated and phosphorylated β-catenin within a 450 kDa Axin1-based complex and in a distinct, Axin1-free complex of 200 kDa. These results argue that during Wnt stimulation, phosphorylated β-catenin is released from the Axin1 complex but fails to undergo immediate degradation. Importantly, in APC-mutant cancer cells, the distribution of Axin1 and β-catenin complexes strongly resembles that of Wnt-stimulated cells. Our findings argue that Wnt signals and APC mutations interfere with the turnover of phosphorylated β-catenin. Furthermore, our results suggest that the accumulation of small-sized β-catenin complexes may serve as an indicator of Wnt pathway activity in primary cancer cells. PMID:25392450

  11. Maternal Inflammation Contributes to Brain Overgrowth and Autism-Associated Behaviors through Altered Redox Signaling in Stem and Progenitor Cells

    Directory of Open Access Journals (Sweden)

    Janel E. Le Belle

    2014-11-01

    Full Text Available A period of mild brain overgrowth with an unknown etiology has been identified as one of the most common phenotypes in autism. Here, we test the hypothesis that maternal inflammation during critical periods of embryonic development can cause brain overgrowth and autism-associated behaviors as a result of altered neural stem cell function. Pregnant mice treated with low-dose lipopolysaccharide at embryonic day 9 had offspring with brain overgrowth, with a more pronounced effect in PTEN heterozygotes. Exposure to maternal inflammation also enhanced NADPH oxidase (NOX-PI3K pathway signaling, stimulated the hyperproliferation of neural stem and progenitor cells, increased forebrain microglia, and produced abnormal autism-associated behaviors in affected pups. Our evidence supports the idea that a prenatal neuroinflammatory dysregulation in neural stem cell redox signaling can act in concert with underlying genetic susceptibilities to affect cellular responses to environmentally altered cellular levels of reactive oxygen species.

  12. Processing of simple and complex acoustic signals in a tonotopically organized ear.

    Science.gov (United States)

    Hummel, Jennifer; Wolf, Konstantin; Kössl, Manfred; Nowotny, Manuela

    2014-12-01

    Processing of complex signals in the hearing organ remains poorly understood. This paper aims to contribute to this topic by presenting investigations on the mechanical and neuronal response of the hearing organ of the tropical bushcricket species Mecopoda elongata to simple pure tone signals as well as to the conspecific song as a complex acoustic signal. The high-frequency hearing organ of bushcrickets, the crista acustica (CA), is tonotopically tuned to frequencies between about 4 and 70 kHz. Laser Doppler vibrometer measurements revealed a strong and dominant low-frequency-induced motion of the CA when stimulated with either pure tone or complex stimuli. Consequently, the high-frequency distal area of the CA is more strongly deflected by low-frequency-induced waves than by high-frequency-induced waves. This low-frequency dominance will have strong effects on the processing of complex signals. Therefore, we additionally studied the neuronal response of the CA to native and frequency-manipulated chirps. Again, we found a dominant influence of low-frequency components within the conspecific song, indicating that the mechanical vibration pattern highly determines the neuronal response of the sensory cells. Thus, we conclude that the encoding of communication signals is modulated by ear mechanics. PMID:25339727

  13. Synthesis of high-complexity rhythmic signals for closed-loop electrical neuromodulation.

    Science.gov (United States)

    Zalay, Osbert C; Bardakjian, Berj L

    2013-06-01

    We propose an approach to synthesizing high-complexity rhythmic signals for closed-loop electrical neuromodulation using cognitive rhythm generator (CRG) networks, wherein the CRG is a hybrid oscillator comprised of (1) a bank of neuronal modes, (2) a ring device (clock), and (3) a static output nonlinearity (mapper). Networks of coupled CRGs have been previously implemented to simulate the electrical activity of biological neural networks, including in silico models of epilepsy, producing outputs of similar waveform and complexity to the biological system. This has enabled CRG network models to be used as platforms for testing seizure control strategies. Presently, we take the application one step further, envisioning therapeutic CRG networks as rhythmic signal generators creating neuromimetic signals for stimulation purposes, motivated by recent research indicating that stimulus complexity and waveform characteristics influence neuromodulation efficacy. To demonstrate this concept, an epileptiform CRG network generating spontaneous seizure-like events (SLEs) was coupled to a therapeutic CRG network, forming a closed-loop neuromodulation system. SLEs are associated with low-complexity dynamics and high phase coherence in the network. The tuned therapeutic network generated a high-complexity, multi-banded rhythmic stimulation signal with prominent theta and gamma-frequency power that suppressed SLEs and increased dynamic complexity in the epileptiform network, as measured by a relative increase in the maximum Lyapunov exponent and decrease in phase coherence. CRG-based neuromodulation outperformed both low and high-frequency periodic pulse stimulation, suggesting that neuromodulation using complex, biomimetic signals may provide an improvement over conventional electrical stimulation techniques for treating neurological disorders such as epilepsy. PMID:23501170

  14. Biomedical image and signal de-noising using dual tree complex wavelet transform

    Science.gov (United States)

    Rizi, F. Yousefi; Noubari, H. Ahmadi; Setarehdan, S. K.

    2011-10-01

    Dual tree complex wavelet transform(DTCWT) is a form of discrete wavelet transform, which generates complex coefficients by using a dual tree of wavelet filters to obtain their real and imaginary parts. The purposes of de-noising are reducing noise level and improving signal to noise ratio (SNR) without distorting the signal or image. This paper proposes a method for removing white Gaussian noise from ECG signals and biomedical images. The discrete wavelet transform (DWT) is very valuable in a large scope of de-noising problems. However, it has limitations such as oscillations of the coefficients at a singularity, lack of directional selectivity in higher dimensions, aliasing and consequent shift variance. The complex wavelet transform CWT strategy that we focus on in this paper is Kingsbury's and Selesnick's dual tree CWT (DTCWT) which outperforms the critically decimated DWT in a range of applications, such as de-noising. Each complex wavelet is oriented along one of six possible directions, and the magnitude of each complex wavelet has a smooth bell-shape. In the final part of this paper, we present biomedical image and signal de-noising by the means of thresholding magnitude of the wavelet coefficients.

  15. Effect of Dietary Complex Lipids on the Biosynthesis of Piglet Brain Gangliosides.

    Science.gov (United States)

    Reis, Marlon M; Bermingham, Emma N; Reis, Mariza G; Deb-Choudhury, Santanu; MacGibbon, Alastair; Fong, Bertram; McJarrow, Paul; Bibiloni, Rodrigo; Bassett, Shalome A; Roy, Nicole C

    2016-02-17

    Gangliosides, found in mammalian milk, are known for their roles in brain development of the newborn. However, the mechanism involved in the impact of dietary gangliosides on brain metabolism is not fully understood. The impact of diets containing complex lipids rich in milk-derived ganglioside GD3 on the biosynthesis of gangliosides (assessed from the incorporation of deuterium) in the frontal lobe of a piglet model is reported. Higher levels of incorporation of deuterium was observed in the GM1 and GD1a containing stearic acid in samples from piglets fed milk containing 18.2 μg/mL of GD3 compared to that in those fed milk containing 25 μg/mL of GD3. This could suggest that the gangliosides from the diet may be used as a precursor for de novo biosynthesis of brain gangliosides or lead to the reduction of de novo biosynthesis of these gangliosides. This effect was more pronounced in the left compared to that in the right brain hemisphere. PMID:26808587

  16. Supplementation with complex milk lipids during brain development promotes neuroplasticity without altering myelination or vascular density

    Directory of Open Access Journals (Sweden)

    Rosamond B. Guillermo

    2015-03-01

    Full Text Available Background: Supplementation with complex milk lipids (CML during postnatal brain development has been shown to improve spatial reference learning in rats. Objective: The current study examined histo-biological changes in the brain following CML supplementation and their relationship to the observed improvements in memory. Design: The study used the brain tissues from the rats (male Wistar, 80 days of age after supplementing with either CML or vehicle during postnatal day 10–80. Immunohistochemical staining of synaptophysin, glutamate receptor-1, myelin basic protein, isolectin B-4, and glial fibrillary acidic protein was performed. The average area and the density of the staining and the numbers of astrocytes and capillaries were assessed and analysed. Results: Compared with control rats, CML supplementation increased the average area of synaptophysin staining and the number of GFAP astrocytes in the CA3 sub-region of the hippocampus (p<0.01, but not in the CA4 sub-region. The supplementation also led to an increase in dopamine output in the striatum that was related to nigral dopamine expression (p<0.05, but did not alter glutamate receptors, myelination or vascular density. Conclusion: CML supplementation may enhance neuroplasticity in the CA3 sub-regions of the hippocampus. The brain regions-specific increase of astrocyte may indicate a supporting role for GFAP in synaptic plasticity. CML supplementation did not associate with postnatal white matter development or vascular remodelling.

  17. Pseudo-stokes vector from complex signal representation of a speckle pattern and its applications to micro-displacement measurement

    DEFF Research Database (Denmark)

    Wang, W.; Ishijima, R.; Matsuda, A.;

    2010-01-01

    the intensity speckle pattern, which converts the original real-valued signal into a complex signal. In closest analogy to the polarisation of a vector wave, the Stokes-like vector constructed from the spatial derivative of the generated complex signal has been applied for correlation. Experimental...

  18. Directional dual-tree complex wavelet packet transforms for processing quadrature signals.

    Science.gov (United States)

    Serbes, Gorkem; Gulcur, Halil Ozcan; Aydin, Nizamettin

    2016-03-01

    Quadrature signals containing in-phase and quadrature-phase components are used in many signal processing applications in every field of science and engineering. Specifically, Doppler ultrasound systems used to evaluate cardiovascular disorders noninvasively also result in quadrature format signals. In order to obtain directional blood flow information, the quadrature outputs have to be preprocessed using methods such as asymmetrical and symmetrical phasing filter techniques. These resultant directional signals can be employed in order to detect asymptomatic embolic signals caused by small emboli, which are indicators of a possible future stroke, in the cerebral circulation. Various transform-based methods such as Fourier and wavelet were frequently used in processing embolic signals. However, most of the times, the Fourier and discrete wavelet transforms are not appropriate for the analysis of embolic signals due to their non-stationary time-frequency behavior. Alternatively, discrete wavelet packet transform can perform an adaptive decomposition of the time-frequency axis. In this study, directional discrete wavelet packet transforms, which have the ability to map directional information while processing quadrature signals and have less computational complexity than the existing wavelet packet-based methods, are introduced. The performances of proposed methods are examined in detail by using single-frequency, synthetic narrow-band, and embolic quadrature signals. PMID:25388779

  19. Overcoming the signaling defect of Lyn-sequestering, signal-curtailing FcepsilonRI dimers: aggregated dimers can dissociate from Lyn and form signaling complexes with Syk.

    Science.gov (United States)

    Lara, M; Ortega, E; Pecht, I; Pfeiffer, J R; Martinez, A M; Lee, R J; Surviladze, Z; Wilson, B S; Oliver, J M

    2001-10-15

    Clustering the tetrameric (alphabetagamma(2)) IgE receptor, FcepsilonRI, on basophils and mast cells activates the Src-family tyrosine kinase, Lyn, which phosphorylates FcepsilonRI beta and gamma subunit tyrosines, creating binding sites for the recruitment and activation of Syk. We reported previously that FcepsilonRI dimers formed by a particular anti-FcepsilonRI alpha mAb (H10) initiate signaling through Lyn activation and FcepsilonRI subunit phosphorylation, but cause only modest activation of Syk and little Ca(2+) mobilization and secretion. Curtailed signaling was linked to the formation of unusual, detergent-resistant complexes between Lyn and phosphorylated receptor subunits. Here, we show that H10-FcepsilonRI multimers, induced by adding F(ab')(2) of goat anti-mouse IgG to H10-treated cells, support strong Ca(2+) mobilization and secretion. Accompanying the recovery of signaling, H10-FcepsilonRI multimers do not form stable complexes with Lyn and do support the phosphorylation of Syk and phospholipase Cgamma2. Immunogold electron microscopy showed that H10-FcepsilonRI dimers colocalize preferentially with Lyn and are rarely within the osmiophilic "signaling domains" that accumulate FcepsilonRI and Syk in Ag-treated cells. In contrast, H10-FcepsilonRI multimers frequently colocalize with Syk within osmiophilic patches. In sucrose gradient centrifugation analyses of detergent-extracted cells, H10-treated cells show a more complete redistribution of FcepsilonRI beta from heavy (detergent-soluble) to light (Lyn-enriched, detergent-resistant) fractions than cells activated with FcepsilonRI multimers. We hypothesize that restraints imposed by the particular orientation of H10-FcepsilonRI dimers traps them in signal-initiating Lyn microdomains, and that converting the dimers to multimers permits receptors to dissociate from Lyn and redistribute to separate membrane domains that support Syk-dependent signal propagation. PMID:11591756

  20. Influence of Signal Intensity Non-Uniformity on Brain Volumetry Using an Atlas-Based Method

    International Nuclear Information System (INIS)

    Many studies have reported pre-processing effects for brain volumetry; however, no study has investigated whether non-parametric non-uniform intensity normalization (N3) correction processing results in reduced system dependency when using an atlas-based method. To address this shortcoming, the present study assessed whether N3 correction processing provides reduced system dependency in atlas-based volumetry. Contiguous sagittal T1-weighted images of the brain were obtained from 21 healthy participants, by using five magnetic resonance protocols. After image preprocessing using the Statistical Parametric Mapping 5 software, we measured the structural volume of the segmented images with the WFU-PickAtlas software. We applied six different bias-correction levels (Regularization 10, Regularization 0.0001, Regularization 0, Regularization 10 with N3, Regularization 0.0001 with N3, and Regularization 0 with N3) to each set of images. The structural volume change ratio (%) was defined as the change ratio (%) = (100 X[measured volume - mean volume of five magnetic resonance protocols] / mean volume of five magnetic resonance protocols) for each bias-correction level. A low change ratio was synonymous with lower system dependency. The results showed that the images with the N3 correction had a lower change ratio compared with those without the N3 correction. The present study is the first atlas-based volumetry study to show that the precision of atlas-based volumetry improves when using N3-corrected images. Therefore, correction for signal intensity non-uniformity is strongly advised for multi-scanner or multi-site imaging trials.

  1. Use of multiple singular value decompositions to analyze complex intracellular calcium ion signals

    KAUST Repository

    Martinez, Josue G.

    2009-12-01

    We compare calcium ion signaling (Ca(2+)) between two exposures; the data are present as movies, or, more prosaically, time series of images. This paper describes novel uses of singular value decompositions (SVD) and weighted versions of them (WSVD) to extract the signals from such movies, in a way that is semi-automatic and tuned closely to the actual data and their many complexities. These complexities include the following. First, the images themselves are of no interest: all interest focuses on the behavior of individual cells across time, and thus, the cells need to be segmented in an automated manner. Second, the cells themselves have 100+ pixels, so that they form 100+ curves measured over time, so that data compression is required to extract the features of these curves. Third, some of the pixels in some of the cells are subject to image saturation due to bit depth limits, and this saturation needs to be accounted for if one is to normalize the images in a reasonably un-biased manner. Finally, the Ca(2+) signals have oscillations or waves that vary with time and these signals need to be extracted. Thus, our aim is to show how to use multiple weighted and standard singular value decompositions to detect, extract and clarify the Ca(2+) signals. Our signal extraction methods then lead to simple although finely focused statistical methods to compare Ca(2+) signals across experimental conditions.

  2. Dataflow/Actor-Oriented language for the design of complex signal processing systems

    OpenAIRE

    Lucarz, Christophe; Mattavelli, Marco; Wipliez, Matthieu; Roquier, Ghislain; Raulet, Mickael; Janneck, Jörn W.; Miller, Ian D.; Parlour, David B.

    2008-01-01

    International audience Signal processing algorithms become more and more complex and the algorithm architecture adaptation and design processes cannot any longer rely only on the intuition of the designers to build efficient systems. Specific tools and methods are needed to cope with the increasing complexity of both algorithms and platforms. This paper presents a new framework which allows the specification, design, simulation and implementation of a system operating at a higher level of ...

  3. Performance Analysis of a Hardware Implemented Complex Signal Kurtosis Radio-Frequency Interference Detector

    Science.gov (United States)

    Bradley, Damon C.; Mohammed, Priscilla N.; Schoenwald, Adam J.; Piepmeier, Jeffrey R.; Wong, Mark

    2016-01-01

    Radio-frequency interference (RFI) is a known problem for passive remote sensing as evidenced in the L-band radiometers SMOS, Aquarius and more recently, SMAP. Various algorithms have been developed and implemented on SMAP to improve science measurements. This was achieved by the use of a digital microwave radiometer. RFI mitigation becomes more challenging for microwave radiometers operating at higher frequencies in shared allocations. At higher frequencies larger bandwidths are also desirable for lower measurement noise further adding to processing challenges. This work focuses on finding improved RFI mitigation techniques that will be effective at additional frequencies and at higher bandwidths. To aid the development and testing of applicable detection and mitigation techniques, a wide-band RFI algorithm testing environment has been developed using the Reconfigurable Open Architecture Computing Hardware System (ROACH) built by the Collaboration for Astronomy Signal Processing and Electronics Research (CASPER) Group. The testing environment also consists of various test equipment used to reproduce typical signals that a radiometer may see including those with and without RFI. The testing environment permits quick evaluations of RFI mitigation algorithms as well as show that they are implementable in hardware. The algorithm implemented is a complex signal kurtosis detector which was modeled and simulated. The complex signal kurtosis detector showed improved performance over the real kurtosis detector under certain conditions. The real kurtosis is implemented on SMAP at 24 MHz bandwidth. The complex signal kurtosis algorithm was then implemented in hardware at 200 MHz bandwidth using the ROACH. In this work, performance of the complex signal kurtosis and the real signal kurtosis are compared. Performance evaluations and comparisons in both simulation as well as experimental hardware implementations were done with the use of receiver operating characteristic (ROC

  4. Major Histocompatibility Complex class I proteins are critical for maintaining neuronal structural complexity in the aging brain.

    Science.gov (United States)

    Lazarczyk, Maciej J; Kemmler, Julia E; Eyford, Brett A; Short, Jennifer A; Varghese, Merina; Sowa, Allison; Dickstein, Daniel R; Yuk, Frank J; Puri, Rishi; Biron, Kaan E; Leist, Marcel; Jefferies, Wilfred A; Dickstein, Dara L

    2016-01-01

    Major histocompatibility complex class I (MHCI) proteins have been implicated in neuronal function through the modulation of neuritogenesis, synaptogenesis, synaptic plasticity, and memory consolidation during development. However, the involvement of MHCI in the aged brain is unclear. Here we demonstrate that MHCI deficiency results in significant dendritic atrophy along with an increase in thin dendritic spines and a reduction in stubby spines in the hippocampus of aged (12 month old) mice. Ultrastructural analyses revealed a decrease in spine head diameter and post synaptic density (PSD) area, as well as an increase in overall synapse density, and non-perforated, small spines. Interestingly, we found that the changes in synapse density and morphology appear relatively late (after the age of 6 months). Finally, we found a significant age dependent increase in the levels of the glutamate receptor, GluN2B in aged MHCI knockout mice, with no change in GluA2/3, VGluT1, PSD95 or synaptophysin. These results indicate that MHCI may be also be involved in maintaining brain integrity at post-developmental stages notably in the modulation of neuronal and spine morphology and synaptic function during non-pathological aging which could have significant implications for cognitive function. PMID:27229916

  5. Genome-wide coexpression of steroid receptors in the mouse brain: Identifying signaling pathways and functionally coordinated regions.

    Science.gov (United States)

    Mahfouz, Ahmed; Lelieveldt, Boudewijn P F; Grefhorst, Aldo; van Weert, Lisa T C M; Mol, Isabel M; Sips, Hetty C M; van den Heuvel, José K; Datson, Nicole A; Visser, Jenny A; Reinders, Marcel J T; Meijer, Onno C

    2016-03-01

    Steroid receptors are pleiotropic transcription factors that coordinate adaptation to different physiological states. An important target organ is the brain, but even though their effects are well studied in specific regions, brain-wide steroid receptor targets and mediators remain largely unknown due to the complexity of the brain. Here, we tested the idea that novel aspects of steroid action can be identified through spatial correlation of steroid receptors with genome-wide mRNA expression across different regions in the mouse brain. First, we observed significant coexpression of six nuclear receptors (NRs) [androgen receptor (Ar), estrogen receptor alpha (Esr1), estrogen receptor beta (Esr2), glucocorticoid receptor (Gr), mineralocorticoid receptor (Mr), and progesterone receptor (Pgr)] with sets of steroid target genes that were identified in single brain regions. These coexpression relationships were also present in distinct other brain regions, suggestive of as yet unidentified coordinate regulation of brain regions by, for example, glucocorticoids and estrogens. Second, coexpression of a set of 62 known NR coregulators and the six steroid receptors in 12 nonoverlapping mouse brain regions revealed selective downstream pathways, such as Pak6 as a mediator for the effects of Ar and Gr on dopaminergic transmission. Third, Magel2 and Irs4 were identified and validated as strongly responsive targets to the estrogen diethylstilbestrol in the mouse hypothalamus. The brain- and genome-wide correlations of mRNA expression levels of six steroid receptors that we provide constitute a rich resource for further predictions and understanding of brain modulation by steroid hormones. PMID:26811448

  6. MRI and pathological examination of post-mortem brains: the problem of white matter high signal areas

    International Nuclear Information System (INIS)

    We examined 21 brains from individuals more than 65 years of age by MRI and neuropathological methods to study the frequency and morphology of white matter changes. There were 16 brains from neurologically normal subjects (Group 1) while the remaining 5 (Group 2) had neurological disturbances. In Group 1 MRI showed high signal areas in the periventricular white matter in 12 brains and in the deep white matter in 9. All had focal areas, with confluent zones in 4; 3 cystic infarcts were also detected. Neuropathology in this Group showed periventricular changes of variable extent in all cases, vacuolated myelin around the perivascular spaces in 14 and degenerate myelin in 4. Macroscopic inspection showed 3 cystic lacunar infarcts, while areas of recent infarction were present on histology in 2. Four of the Group 2 brains had periventricular MRI changes; high signal areas in deep white matter were focal in 2 and confluent in 1. Cystic infarcts were detected in 3 cases. Neuropathology showed periventricular changes in all the brains; in 4 myelin around the perivascular spaces was vacuolated while degenerate myelin was demonstrated in 1. There were also old (1) and recent (2) lacunar infarcts. (orig.)

  7. MRI and pathological examination of post-mortem brains: the problem of white matter high signal areas

    Energy Technology Data Exchange (ETDEWEB)

    Scarpelli, M. (Inst. of Pathological Anatomy and Histopathology, Ancona Univ. (Italy)); Salvolini, U. (Magnetic Resonance Research Unit, Ancona Univ. (Italy)); Diamanti, L. (Inst. of Pathological Anatomy and Histopathology, Ancona Univ. (Italy)); Montironi, R. (Inst. of Pathological Anatomy and Histopathology, Ancona Univ. (Italy)); Chiaromoni, L. (Magnetic Resonance Research Unit, Ancona Univ. (Italy)); Maricotti, M. (Magnetic Resonance Research Unit, Ancona Univ. (Italy))

    1994-07-01

    We examined 21 brains from individuals more than 65 years of age by MRI and neuropathological methods to study the frequency and morphology of white matter changes. There were 16 brains from neurologically normal subjects (Group 1) while the remaining 5 (Group 2) had neurological disturbances. In Group 1 MRI showed high signal areas in the periventricular white matter in 12 brains and in the deep white matter in 9. All had focal areas, with confluent zones in 4; 3 cystic infarcts were also detected. Neuropathology in this Group showed periventricular changes of variable extent in all cases, vacuolated myelin around the perivascular spaces in 14 and degenerate myelin in 4. Macroscopic inspection showed 3 cystic lacunar infarcts, while areas of recent infarction were present on histology in 2. Four of the Group 2 brains had periventricular MRI changes; high signal areas in deep white matter were focal in 2 and confluent in 1. Cystic infarcts were detected in 3 cases. Neuropathology showed periventricular changes in all the brains; in 4 myelin around the perivascular spaces was vacuolated while degenerate myelin was demonstrated in 1. There were also old (1) and recent (2) lacunar infarcts. (orig.)

  8. Hypoxic preconditioning induces neuroprotective stanniocalcin-1 in brain via IL-6 signaling

    DEFF Research Database (Denmark)

    Westberg, Johan A; Serlachius, Martina; Lankila, Petri;

    2007-01-01

    mRNA levels in brains of wild-type and IL-6 deficient mice. Furthermore, we monitored the Stc-1 response in brains of wild-type and transgenic mice, overexpressing IL-6 in the astroglia, before and after induced brain injury. RESULTS: Hypoxic preconditioning induced an upregulated expression of Stc...

  9. Suppressor of cytokine Signaling-3 inhibits interleukin-1 signaling by targeting the TRAF-6/TAK1 complex

    DEFF Research Database (Denmark)

    Frobøse, Helle; Rønn, Sif Groth; Heding, Peter E; Mendoza, Heidi; Cohen, Philip; Mandrup-Poulsen, Thomas; Billestrup, Nils

    2006-01-01

    IL-1 plays a major role in inflammation and autoimmunity through activation of nuclear factor kappa B (NFkappaB) and MAPKs. Although a great deal is known about the mechanism of activation of NFkappaB and MAPKs by IL-1, much less is known about the down-regulation of this pathway. Suppressor of...... cytokine signaling (SOCS)-3 was shown to inhibit IL-1-induced transcription and activation of NFkappaB and the MAPKs JNK and p38, but the mechanism is unknown. We show here that SOCS-3 inhibits NFkappaB-dependent transcription induced by overexpression of the upstream IL-1 signaling molecules MyD88, IL-1R......-activated kinase 1, TNF receptor-associated factor (TRAF)6, and TGFbeta-activated kinase (TAK)1, but not when the MAP3K MAPK/ERK kinase kinase-1 is used instead of TAK1, indicating that the target for SOCS-3 is the TRAF6/TAK1 signaling complex. By coimmunoprecipitation, it was shown that SOCS-3 inhibited the...

  10. The early signal substances induced by heat stress in brains of mice

    Institute of Scientific and Technical Information of China (English)

    Chunxu WANG; Hanxing WANG

    2008-01-01

    To study the effects of early signal substances induced by heat stress in brains of Kunming mice, six-month-old mice (n=72) were pretreated with heat stress and subsequent ischemia/reperfusion by clipping of their bilateral cervical common arteries for 7 min. According to different treatments, animals were randomly divided into four groups: (1) normal control group; (2) heat stress pre-treatment followed by ischemia and reperfusion group (HS/IR); (3) ischemia and reperfusion group (IR); (4) heat stress group (HS). Animals in the later three groups were subdivided into 3 subgroups (1 day, 4 days, 14 days), respectively. The changes in the expression of cAMP res-ponse element binding protein (CREB) and calcitonin gene-related peptide (CGRP) were detected by immuno-histochemistry and computer image analysis methods. The results showed that compared with the normal group, the expressions of CREB in the hippocampal CA1 region increased significantly in the HS, HS/IR and IR groups (P<0.05). Compared to the normal group, heat stress could result in CGRP excretion and redistribution in the cerebrum, with the highest level in the 4 d HS/IR group. Following heat stress, CGRP immunoreactivity was observed in varicose fibers and neuronal perikarya within the CA1 region. The results indicate that heat stress can induce CREB expression, which in turn stimulates CGRP secretion.

  11. Neuroprotective Effects of Physical Activity on the Brain A Closer Look at Trophic Factor Signaling

    Directory of Open Access Journals (Sweden)

    Cristy ePhillips

    2014-06-01

    Full Text Available While the relationship between increased physical activity and cognitive ability hasbeen conjectured for centuries, only recently have the mechanisms underlying this relationship began to emerge. Convergent evidence suggests that physical activity offers an affordable and effective method to improve cognitive function in all ages, particularly the elderly who are most vulnerable to neurodegenerative disorders. In addition to improving cardiac and immune function, physical activity alters trophic factor signaling and, in turn, neuronal function and structure in areas critical for cognition. Sustained exercise plays a role in modulating anti-inflammatory effects and may play a role in preserving cognitive function in aging and neuropathological conditions. Moreover, recent evidence suggests that myokines released by exercising muscles affect the expression of brain-derived neurotrophic factor synthesis in the dentate gyrus of the hippocampus, a finding that could lead to the identification of new and therapeutically important mediating factors. Given the growing numbers of individuals with cognitive impairment in the US population, a better understanding of how these factors work in aggregate to contribute to cognition is imperative, and constitutes an important first step toward developing non-pharmacological therapeutic strategies to improve cognition in vulnerable populations.

  12. Effects of beta-alanine supplementation on brain homocarnosine/carnosine signal and cognitive function: an exploratory study.

    Directory of Open Access Journals (Sweden)

    Marina Yazigi Solis

    Full Text Available Two independent studies were conducted to examine the effects of 28 d of beta-alanine supplementation at 6.4 g d(-1 on brain homocarnosine/carnosine signal in omnivores and vegetarians (Study 1 and on cognitive function before and after exercise in trained cyclists (Study 2.In Study 1, seven healthy vegetarians (3 women and 4 men and seven age- and sex-matched omnivores undertook a brain 1H-MRS exam at baseline and after beta-alanine supplementation. In study 2, nineteen trained male cyclists completed four 20-Km cycling time trials (two pre supplementation and two post supplementation, with a battery of cognitive function tests (Stroop test, Sternberg paradigm, Rapid Visual Information Processing task being performed before and after exercise on each occasion.In Study 1, there were no within-group effects of beta-alanine supplementation on brain homocarnosine/carnosine signal in either vegetarians (p = 0.99 or omnivores (p = 0.27; nor was there any effect when data from both groups were pooled (p = 0.19. Similarly, there was no group by time interaction for brain homocarnosine/carnosine signal (p = 0.27. In study 2, exercise improved cognitive function across all tests (P 0.05 of beta-alanine supplementation on response times or accuracy for the Stroop test, Sternberg paradigm or RVIP task at rest or after exercise.28 d of beta-alanine supplementation at 6.4 g d(-1 appeared not to influence brain homocarnosine/carnosine signal in either omnivores or vegetarians; nor did it influence cognitive function before or after exercise in trained cyclists.

  13. Effects of Beta-Alanine Supplementation on Brain Homocarnosine/Carnosine Signal and Cognitive Function: An Exploratory Study

    OpenAIRE

    Marina Yazigi Solis; Simon Cooper; Hobson, Ruth M; Artioli, Guilherme G.; Otaduy, Maria C.; Hamilton Roschel; Jacques Robertson; Daniel Martin; Vitor S Painelli; Harris, Roger C; Bruno Gualano; Craig Sale

    2015-01-01

    Objectives Two independent studies were conducted to examine the effects of 28 d of beta-alanine supplementation at 6.4 g d-1 on brain homocarnosine/carnosine signal in omnivores and vegetarians (Study 1) and on cognitive function before and after exercise in trained cyclists (Study 2). Methods In Study 1, seven healthy vegetarians (3 women and 4 men) and seven age- and sex-matched omnivores undertook a brain 1H-MRS exam at baseline and after beta-alanine supplementation. In study 2, nineteen...

  14. Imaging decreased brain docosahexaenoic acid metabolism and signaling in iPLA2β (VIA)-deficient mice

    OpenAIRE

    Basselin, Mireille; Rosa, Angelo O.; Ramadan, Epolia; Cheon, Yewon; Chang, Lisa; Chen, Mei; Greenstein, Deanna; Wohltmann, Mary; Turk, John; Rapoport, Stanley I.

    2010-01-01

    Ca2+-independent phospholipase A2β (iPLA2β) selectively hydrolyzes docosahexaenoic acid (DHA, 22:6n-3) in vitro from phospholipid. Mutations in the PLA2G6 gene encoding this enzyme occur in patients with idiopathic neurodegeneration plus brain iron accumulation and dystonia-parkinsonism without iron accumulation, whereas mice lacking PLA2G6 show neurological dysfunction and neuropathology after 13 months. We hypothesized that brain DHA metabolism and signaling would be reduced in 4-month-old ...

  15. Weak signal transmission in complex networks and its application in detecting connectivity.

    Science.gov (United States)

    Liang, Xiaoming; Liu, Zonghua; Li, Baowen

    2009-10-01

    We present a network model of coupled oscillators to study how a weak signal is transmitted in complex networks. Through both theoretical analysis and numerical simulations, we find that the response of other nodes to the weak signal decays exponentially with their topological distance to the signal source and the coupling strength between two neighboring nodes can be figured out by the responses. This finding can be conveniently used to detect the topology of unknown network, such as the degree distribution, clustering coefficient and community structure, etc., by repeatedly choosing different nodes as the signal source. Through four typical networks, i.e., the regular one dimensional, small world, random, and scale-free networks, we show that the features of network can be approximately given by investigating many fewer nodes than the network size, thus our approach to detect the topology of unknown network may be efficient in practical situations with large network size. PMID:19905385

  16. Stochastic effects as a force to increase the complexity of signaling networks

    KAUST Repository

    Kuwahara, Hiroyuki

    2013-07-29

    Cellular signaling networks are complex and appear to include many nonfunctional elements. Recently, it was suggested that nonfunctional interactions of proteins cause signaling noise, which, perhaps, shapes the signal transduction mechanism. However, the conditions under which molecular noise influences cellular information processing remain unclear. Here, we explore a large number of simple biological models of varying network sizes to understand the architectural conditions under which the interactions of signaling proteins can exhibit specific stochastic effects - called deviant effects - in which the average behavior of a biological system is substantially altered in the presence of molecular noise. We find that a small fraction of these networks does exhibit deviant effects and shares a common architectural feature whereas most of the networks show only insignificant levels of deviations. Interestingly, addition of seemingly unimportant interactions into protein networks gives rise to deviant effects.

  17. Brain source localization: A new method based on MUltiple SIgnal Classification algorithm and spatial sparsity of the field signal for electroencephalogram measurements

    Science.gov (United States)

    Vergallo, P.; Lay-Ekuakille, A.

    2013-08-01

    Brain activity can be recorded by means of EEG (Electroencephalogram) electrodes placed on the scalp of the patient. The EEG reflects the activity of groups of neurons located in the head, and the fundamental problem in neurophysiology is the identification of the sources responsible of brain activity, especially if a seizure occurs and in this case it is important to identify it. The studies conducted in order to formalize the relationship between the electromagnetic activity in the head and the recording of the generated external field allow to know pattern of brain activity. The inverse problem, that is given the sampling field at different electrodes the underlying asset must be determined, is more difficult because the problem may not have a unique solution, or the search for the solution is made difficult by a low spatial resolution which may not allow to distinguish between activities involving sources close to each other. Thus, sources of interest may be obscured or not detected and known method in source localization problem as MUSIC (MUltiple SIgnal Classification) could fail. Many advanced source localization techniques achieve a best resolution by exploiting sparsity: if the number of sources is small as a result, the neural power vs. location is sparse. In this work a solution based on the spatial sparsity of the field signal is presented and analyzed to improve MUSIC method. For this purpose, it is necessary to set a priori information of the sparsity in the signal. The problem is formulated and solved using a regularization method as Tikhonov, which calculates a solution that is the better compromise between two cost functions to minimize, one related to the fitting of the data, and another concerning the maintenance of the sparsity of the signal. At the first, the method is tested on simulated EEG signals obtained by the solution of the forward problem. Relatively to the model considered for the head and brain sources, the result obtained allows to

  18. Brain source localization: a new method based on MUltiple SIgnal Classification algorithm and spatial sparsity of the field signal for electroencephalogram measurements.

    Science.gov (United States)

    Vergallo, P; Lay-Ekuakille, A

    2013-08-01

    Brain activity can be recorded by means of EEG (Electroencephalogram) electrodes placed on the scalp of the patient. The EEG reflects the activity of groups of neurons located in the head, and the fundamental problem in neurophysiology is the identification of the sources responsible of brain activity, especially if a seizure occurs and in this case it is important to identify it. The studies conducted in order to formalize the relationship between the electromagnetic activity in the head and the recording of the generated external field allow to know pattern of brain activity. The inverse problem, that is given the sampling field at different electrodes the underlying asset must be determined, is more difficult because the problem may not have a unique solution, or the search for the solution is made difficult by a low spatial resolution which may not allow to distinguish between activities involving sources close to each other. Thus, sources of interest may be obscured or not detected and known method in source localization problem as MUSIC (MUltiple SIgnal Classification) could fail. Many advanced source localization techniques achieve a best resolution by exploiting sparsity: if the number of sources is small as a result, the neural power vs. location is sparse. In this work a solution based on the spatial sparsity of the field signal is presented and analyzed to improve MUSIC method. For this purpose, it is necessary to set a priori information of the sparsity in the signal. The problem is formulated and solved using a regularization method as Tikhonov, which calculates a solution that is the better compromise between two cost functions to minimize, one related to the fitting of the data, and another concerning the maintenance of the sparsity of the signal. At the first, the method is tested on simulated EEG signals obtained by the solution of the forward problem. Relatively to the model considered for the head and brain sources, the result obtained allows to

  19. Analysis of MRI spectrum of brain abnormalities in tuberous sclerosis complex - data from one institution

    International Nuclear Information System (INIS)

    Tuberous sclerosis complex (TSC) is an autosomal dominant multisystem disorder with gene loci located on chromosomes 9q34 (TSC1) and 16p13 (TSC2). Brain is the most frequently affected organ. We retrospectively reviewed magnetic resonance features of the brain in 92 patients with tuberous sclerosis, examined in our Institute from 1997 to 2006. We analyzed MR imaging of the spectrum of supra- and infratentorial brain lesions encountered in TSC. MR examinations were performed with a 1.5 T scanner. The basic imaging protocol included axial SE T1WI, FSE PD, T2WI, FSE FLAIR images, sagittal T1,T2WI and coronal FLAIR images. Axial T1-WI contrast-enhanced images were obtained in each patient. Cortical tubers were found in 89 of the 92 patients (96.74%) and they have been located in frontal and parietal cerebral lobes predominantly. Cerebellar tubers were found in 12/92 (13.04%), cerebral white matter lesions in 34/92 patients (36.96%), subependymal nodules in 80/92 patients (86.96%) and subependymal giant cell astrocytomas in 11/92 of our patients (11.96%). Partial agenesis of corpus callosum, cortical dysplasia, cerebellar atrophy, intracranial arterial aneurysm, enlargement of ventricles and venous malformation were rare associated findings. Administration of gadolinium was useful in detecting and delineation subependymal giant cell astrocytomas - SGCAs. Our study presents a wide range of MR signs and variance of the cerebral manifestations with TSC patients. (author)

  20. ECG Signal Compression Technique Based on Discrete Wavelet Transform and QRS-Complex Estimation

    Directory of Open Access Journals (Sweden)

    Ahmed Zakaria

    2010-07-01

    Full Text Available In this paper, an Electrocardiogram (ECG signal is compressed based on discrete wavelet transform (DWT and QRS-complex estimation. The ECG signal is preprocessed by normalization and mean removal. Then, an error signal is formed as the difference between the preprocessed ECG signal and the estimated QRS-complex waveform. This error signal is wavelet transformed and the resulting wavelet coefficients are thresholded by setting to zero all coefficients that are smaller than certain threshold levels. The threshold levels of all subbands are calculated based on Energy Packing Efficiency (EPE such that minimum percentage root mean square difference (PRD and maximum compression ratio (CR are obtained. The resulted thresholded DWT coefficients are coded using the coding technique given in [1], [20]. The compression algorithm was implemented and tested upon records selected from the MIT - BIH arrhythmia database [2]. Simulation results show that the proposed algorithm leads to high CR associated with low distortion level relative to previously reported compression algorithms [1], [14] and [18]. For example, the compression of record 100 using the proposed algorithm yields to CR = 25.15 associated with PRD = 0.7% and PSNR = 45 dB. This achieves compression rate of nearly 128 bit/sec. The main features of this compression algorithm are the high efficiency, high speed and simplicity in design.

  1. A potential neural substrate for processing functional classes of complex acoustic signals.

    Directory of Open Access Journals (Sweden)

    Isabelle George

    Full Text Available Categorization is essential to all cognitive processes, but identifying the neural substrates underlying categorization processes is a real challenge. Among animals that have been shown to be able of categorization, songbirds are particularly interesting because they provide researchers with clear examples of categories of acoustic signals allowing different levels of recognition, and they possess a system of specialized brain structures found only in birds that learn to sing: the song system. Moreover, an avian brain nucleus that is analogous to the mammalian secondary auditory cortex (the caudo-medial nidopallium, or NCM has recently emerged as a plausible site for sensory representation of birdsong, and appears as a well positioned brain region for categorization of songs. Hence, we tested responses in this non-primary, associative area to clear and distinct classes of songs with different functions and social values, and for a possible correspondence between these responses and the functional aspects of songs, in a highly social songbird species: the European starling. Our results clearly show differential neuronal responses to the ethologically defined classes of songs, both in the number of neurons responding, and in the response magnitude of these neurons. Most importantly, these differential responses corresponded to the functional classes of songs, with increasing activation from non-specific to species-specific and from species-specific to individual-specific sounds. These data therefore suggest a potential neural substrate for sorting natural communication signals into categories, and for individual vocal recognition of same-species members. Given the many parallels that exist between birdsong and speech, these results may contribute to a better understanding of the neural bases of speech.

  2. Brain MR imaging in patients with hepatic cirrhosis: relationship between high intensity signal in basal ganglia on T1-weighted images and elemental concentrations in brain

    International Nuclear Information System (INIS)

    In patients with hepatic cirrhosis, the globus pallidus and putamen show high intensity on T1-weighted MRI. While the causes of this high signal have been thought to include paramagnetic substances, especially manganese, no evidence for this has been presented. Autopsy in four cases of hepatic cirrhosis permitted measurement of metal concentrations in brain and histopathological examination. In three cases the globus pallidus showed high intensity on T1-weighted images. Mean manganese concentrations in globus pallidus, putamen and frontal white matter were 3.03 ± 0.38, 2.12 ± 0.37, and 1.38 ± 0.24 (μg/g wet weight), respectively, being approximately four- to almost ten-fold the normal values. Copper concentrations in globus pallidus and putamen were also high, 50 % more than normal. Calcium, iron, zinc and magnesium concentrations were all normal. The fourth case showed no abnormal intensity in the basal ganglia and brain metal concentrations were all normal. Histopathologically, cases with showing high signal remarkable atrophy, necrosis, and deciduation of nerve cells and proliferation of glial cells and microglia in globus pallidus. These findings were similar to those in chronic manganese poisoning. On T1-weighted images, copper deposition shows no abnormal intensity. It is therefore inferred that deposition of highly concentrations of manganese may caused high signal on T1-weighted images and nerve cell death in the globus pallidus. (orig.). With 2 figs., 2 tabs

  3. Effect of naringenin on brain insulin signaling and cognitive functions in ICV-STZ induced dementia model of rats.

    Science.gov (United States)

    Yang, Wenqing; Ma, Jing; Liu, Zheng; Lu, Yongliang; Hu, Bin; Yu, Huarong

    2014-05-01

    Recent evidence indicates that severe abnormalities in brain glucose/energy metabolism and insulin signaling have been documented to take a pivotal role in early sporadic Alzheimer's disease pathology. It has been reported that naringenin (NAR), derived from citrus aurantium, exhibits antioxidant potential and protects the brain against neurodegeneration. The current study was designed to further investigate the protective effect of the NAR on neurodegeneration in a rat model of AD induced by an intracerebroventricular (ICV) injection of streptozotocin (STZ), and to determine whether this neuroprotective effect was associated with brain insulin signaling. Rats were injected bilaterally with ICV-STZ (3 mg/kg), while sham rats received the same volume of vehicle and then supplemented with NAR (25, 50 mg, 100 mg/kg, respectively) for 3 weeks. The ICV-STZ injected rats did not have elevated blood glucose levels. 21 days following ICV-STZ injection, rats treated with NAR had better learning and memory performance in the Morris water maze test compared with rats treated with saline. We demonstrated that NAR increased the mRNA expression of INS and INSR in cerebral cortex and hippocampus. In addition, NAR reversed ICV-STZ induced Tau hyper-phosphorylation in both hippocampus and cerebral cortex through downregulation of glycogen synthase kinase-3β (GSK-3β) activity, a key kinase in the insulin signaling. Brain levels of Abeta, which were elevated in ICV-STZ rats, were significantly reduced in NAR-treated rats via upregulation of insulin degrading enzyme. These effects were mediated by increased insulin and insulin receptors expression in the brain, suggesting that insulin sensitizer agents might have therapeutic efficacy in early AD. PMID:24337945

  4. Heterogeneous intracellular trafficking dynamics of brain-derived neurotrophic factor complexes in the neuronal soma revealed by single quantum dot tracking.

    Science.gov (United States)

    Vermehren-Schmaedick, Anke; Krueger, Wesley; Jacob, Thomas; Ramunno-Johnson, Damien; Balkowiec, Agnieszka; Lidke, Keith A; Vu, Tania Q

    2014-01-01

    Accumulating evidence underscores the importance of ligand-receptor dynamics in shaping cellular signaling. In the nervous system, growth factor-activated Trk receptor trafficking serves to convey biochemical signaling that underlies fundamental neural functions. Focus has been placed on axonal trafficking but little is known about growth factor-activated Trk dynamics in the neuronal soma, particularly at the molecular scale, due in large part to technical hurdles in observing individual growth factor-Trk complexes for long periods of time inside live cells. Quantum dots (QDs) are intensely fluorescent nanoparticles that have been used to study the dynamics of ligand-receptor complexes at the plasma membrane but the value of QDs for investigating ligand-receptor intracellular dynamics has not been well exploited. The current study establishes that QD conjugated brain-derived neurotrophic factor (QD-BDNF) binds to TrkB receptors with high specificity, activates TrkB downstream signaling, and allows single QD tracking capability for long recording durations deep within the soma of live neurons. QD-BDNF complexes undergo internalization, recycling, and intracellular trafficking in the neuronal soma. These trafficking events exhibit little time-synchrony and diverse heterogeneity in underlying dynamics that include phases of sustained rapid motor transport without pause as well as immobility of surprisingly long-lasting duration (several minutes). Moreover, the trajectories formed by dynamic individual BDNF complexes show no apparent end destination; BDNF complexes can be found meandering over long distances of several microns throughout the expanse of the neuronal soma in a circuitous fashion. The complex, heterogeneous nature of neuronal soma trafficking dynamics contrasts the reported linear nature of axonal transport data and calls for models that surpass our generally limited notions of nuclear-directed transport in the soma. QD-ligand probes are poised to provide

  5. Cutting the Gordian knot:Complex signaling in African cichlids is more than multimodal

    Institute of Scientific and Technical Information of China (English)

    Moira J.VAN STAADEN; Adam R.SMITH

    2011-01-01

    The active transmission of information from sender to recelver is a fundamental component of communication,and is therefore a primary facet in evolutionary models of sexual selection.Research in several systetms has underlined the importance of multiple sensory modalities in courtship signals.However,we still tend to think of individuals as having a relatively static signal in consecutive communicative events.While this may be true for certain traits such as body size or coloration,behaviorally modulated signals can quickly violate this assumption.In this work,we explore how intraspecific variation may be an important component of interspeclfic signal divergence using cichlid fishes from Lake Maiawi.Behavloral analyses were made using six species of Malawian cichlids from two divergent genera.while interspecific differences were found between congeners based on species-level analyses of both acoustic and audiovisual signais,intraspecific variation was of a similar magnitude.Specifically,individual fishes were found to possess highiy plastic signal repertoires.This finding was ubiquitous across all species and resulted in a great deal of overlap between heterospecific individuals,despite statistically distinct species means.These results demonstrate that some aspects of courtship in Malawian cichlids are more plastic than previously proposed,and that studies must account for signal variability within individuals.We propose here that bebavioral variability in signaling is important in determining the communication landscape on which signals are perceived.We review potential complexity deriving from multimodal signaling,discuss the sources for such lability,and suggest ways in which is issue may be approached experimentally.

  6. Absence of Doppler signal in transcranial color-coded ultrasonography may be confirmatory for brain death: A case report

    Directory of Open Access Journals (Sweden)

    Mehmet Akif Topçuoğlu

    2015-08-01

    Full Text Available Transcranial Doppler ultrasonography (TCD is a valuable tool for demonstrating cerebral circulatory arrest (CCA in the setting of brain death. Complete reversal of diastolic flow (to-and-fro flow and systolic spikes in bilateral terminal internal carotid arteries and vertebrobasilar circulation are considered as specific sonogram configurations supporting the diagnosis of CCA. Because of the possibility of sonic bone window impermeability, absence of any waveform in TCD is not confirmatory for CCA unless there is documentation of disappearance of a previously well detected signal by the same recording settings. Transcranial color-coded sonography (TCCS with B-mode imaging can reliably detect adequacy of bone windows with clarity contralateral skull and ipsilateral planum temporale visualization. Therefore, absence of detectable intracranial Doppler signal along with available ultrasound window in TCCS can confirm clinical diagnosis of brain death. We herein discuss this entity from the frame of a representative case.

  7. Improved signal processing approaches in an offline simulation of a hybrid brain-computer interface

    OpenAIRE

    Brunner & C.; Allison B.Z.; Krusienski D.J.; Kaiser V.; Muller-Putz G.R.; Pfurtscheller G.; Neuper C.

    2010-01-01

    In a conventional brain–computer interface (BCI) system, users perform mental tasks that yield specific patterns of brain activity. A pattern recognition system determines which brain activity pattern a user is producing and thereby infers the user’s mental task, allowing users to send messages or commands through brain activity alone. Unfortunately, despite extensive research to improve classification accuracy, BCIs almost always exhibit errors, which are sometimes so severe that effective c...

  8. Modulation of Intercellular Calcium Signaling by Melatonin, in Avian and Mammalian Astrocytes, is Brain Region Specific

    OpenAIRE

    Peters, Jennifer L.; Earnest, Barbara J.; Tjalkens, Ronald B.; Cassone, Vincent M.; Zoran, Mark J.

    2005-01-01

    Calcium waves among glial cells impact many central nervous system functions, including neural integration and brain metabolism. Here, we have characterized the modulatory effects of melatonin, a pineal neurohormone that mediates circadian and seasonal processes, on glial calcium waves derived from different brain regions and species. Diencephalic and telencephalic astrocytes, from both chick and mouse brains, expressed melatonin receptor proteins. Further, using the calcium-sensitive dye Flu...

  9. TRPV1 is crucial for proinflammatory STAT3 signaling and thermoregulation-associated pathways in the brain during inflammation.

    Science.gov (United States)

    Yoshida, Ayaka; Furube, Eriko; Mannari, Tetsuya; Takayama, Yasunori; Kittaka, Hiroki; Tominaga, Makoto; Miyata, Seiji

    2016-01-01

    Transient receptor potential vanilloid receptor 1 (TRPV1) is a non-selective cation channel that is stimulated by heat (>43 °C), mechanical/osmotic stimuli, and low pH. The importance of TRPV1 in inflammatory responses has been demonstrated, whereas its participation in brains remains unclear. In the present study, the intracerebroventricular (icv) administration of the TRPV1 agonist resiniferatoxin (RTX) induced the activation of signal transducer and activator of transcription 3 (STAT3) in circumventricular organs (CVOs) and thermoregulation-associated brain regions with a similar patttern to the peripheral and icv administration of lipopolysaccharide (LPS). With the peripheral and icv LPS stimuli, STAT3 activation was significantly lower in Trpv1(-/-) mice than in Trpv1(+/+) mice. The icv administration of RTX induced transient hypothermia, whereas that of the TRPV1 antagonist capsazepine enhanced the magnitude and period of LPS-induced hyperthermia. These results indicate that TRPV1 is important for activating proinflammatory STAT3 signaling and thermoregulation-associated brain pathways in the brain. PMID:27188969

  10. Differentiation of brain metastases by percentagewise quantification of intratumoral-susceptibility-signals at 3 Tesla

    International Nuclear Information System (INIS)

    Introduction: Evaluation of intratumoral-susceptibility-signals (ITSS) in susceptibility-weighted-imaging (SWI) has been reported to improve diagnostic performance for solitary enhancing brain lesions. Due to the distinct morphologic variability of ITSS, standardized evaluation proved to be difficult. We analyzed, if a new postprocessing method using percentagewise quantification (PQ) of ITSS enables differentiation between different entities of cerebral metastases and may thus improve differential diagnosis in cases of unknown primary. Materials and methods: SWI and contrast enhanced T1-weighted MR images were acquired from 84 patients with intracerebral metastases (20 patients with mamma carcinoma (MC), 15 patients with malignant melanoma (MM), 49 patients with bronchial carcinoma (BC)) at 3 Tesla MR. Images were co-registered and enhancing lesions were delineated on T1-weighted images and the outline transferred to the corresponding SWI map. All voxels within the lesion presenting values below a reference value placed in the ventricular system were determined and percentagewise calculated. Results: Diagnostic performance of percentagewise quantification (PQ) of ITSS, as determined with area under the receiver operating characteristic curve (AUC) was excellent (AUC = 0.96; 95% confidence interval (CI) 0.90, 1.00) to discriminate MM from MC, good for the discrimination of MM and BC (AUC = 0.81, 95% CI 0.70, 0.92) and poor for the discrimination of MC and BC (AUC = 0.60; 95% CI 0.47, 0.73). Conclusion: PQ is a new approach for the assessment of SWI that can be used for differential diagnosis of intracerebral metastases. Metastases of MM and MC or BC can be distinguished with high sensitivity and specificity.

  11. The biological behaviour of technetium complexes with particular reference to brain tumours

    International Nuclear Information System (INIS)

    Ionic radionuclide complexes and in particular technetium compounds have long been the reagents of choice for the detection of brain tumours. Despite their lack of tumour specificity detection rates in the region of 80% can be routinely achieved. The most widely-used reagent to date has been sodium pertechnetate but recently a number of other technetium complexes such as DTPA, citrate and glucoheptonate with a more rapid blood clearance and better tumour to blood ratios than pertechnetate have been proposed as alternatives. All of these reagents are anionic complexes of reduced technetium which do not bind to any extent to plasma proteins or to enzymes. They do, however, satisfy the requirements of the ionic model proposed by Van der Pompe which has been outlined in the previous chapter. In the study reported here a number of technetium complexes, citrate, glucoheptonate and n-acetyl cysteine have been compared with pertechnetate with regard to their uptake in a transplantable rhabdomyosarcoma in the rat. The results obtained have then been used to provide a possible explanation for observed differences in clinical performance between these reagents. (Auth.)

  12. Contributions and complexities from the use of in vivo animal models to improve understanding of human neuroimaging signals

    OpenAIRE

    ChrisMartin

    2014-01-01

    Many of the major advances in our understanding of how functional brain imaging signals relate to neuronal activity over the previous two decades have arisen from physiological research studies involving experimental animal models. This approach has been successful partly because it provides opportunities to measure both the hemodynamic changes that underpin many human functional brain imaging techniques and the neuronal activity about which we wish to make inferences. Although research into ...

  13. Low complexity method for spreading sequence estimation of DSSS signal in non-cooperative communication systems*

    Institute of Scientific and Technical Information of China (English)

    Chang Liang; Wang Fuping; Wang Zanji

    2009-01-01

    It is a necessary step to estimate the spreading sequence of direct sequence spread spectrum (DSSS) signal for blind despreading and demodulation in non-cooperative communications. Two innovative and effective detection statistics axe proposed to implement the synchronization and spreading sequence estimation procedure. The proposed algorithm also has a low computational complexity with only linear additions and modifications. Theoretical analysis and simulation results show that the algorithm performs quite well in low SNR environment, and is much better than all the existing typical algorithms with a comprehensive consideration both in performance and computational complexity.

  14. Complexity, signal detection, and the application of ergonomics: reflections on a healthcare case study.

    Science.gov (United States)

    Dekker, Sidney

    2012-05-01

    Complexity is a defining characteristic of healthcare, and ergonomic interventions in clinical practice need to take into account aspects vital for the success or failure of new technology. The introduction of new monitoring technology, for example, creates many ripple effects through clinical relationships and agents' cross-adaptations. This paper uses the signal detection paradigm to account for a case in which multiple clinical decision makers, across power hierarchies and gender gaps, manipulate each others' sensitivities to evidence and decision criteria. These are possible to analyze and predict with an applied ergonomics that is sensitive to the social complexities of the workplace, including power, gender, hierarchy and fuzzy system boundaries. PMID:21813110

  15. Decoding the complex brain: multivariate and multimodal analyses of neuroimaging data

    International Nuclear Information System (INIS)

    various cognitive questions. These methods are used in order to extract features that are inaccessible using univariate / unimodal analytic approaches. To this end, I implemented multivariate partial least squares analysis in study I and II in order to identify neural commonalities and differences between the available and accessible information in memory (study I), and also between episodic encoding and episodic retrieval (study II). Study I provided evidence of a qualitative differences between availability and accessibility signals in memory by linking memory access to modality-independent brain regions, and availability in memory to elevated activity in modality-specific brain regions. Study II provided evidence in support of general and specific memory operations during encoding and retrieval by linking general processes to the joint demands on attentional, executive, and strategic processing, and a process-specific network to core episodic memory function. In study II, III, and IV, I explored whether the age-related changes/differences in one modality were driven by age-related changes/differences in another modality. To this end, study II investigated whether age-related functional differences in hippocampus during an episodic memory task could be accounted for by age-related structural differences. I found that age-related local structural deterioration could partially but not entirely account for age-related diminished hippocampal activation. In study III, I sought to explore whether age-related changes in the prefrontal and occipital cortex during a semantic memory task were driven by local and/or distal gray matter loss. I found that age-related diminished prefrontal activation was driven, at least in part, by local gray matter atrophy, whereas the age-related decline in occipital cortex was accounted for by distal gray matter atrophy. Finally, in study IV, I investigated whether white matter (WM) microstructural differences mediated age-related decline in

  16. Decoding the complex brain: multivariate and multimodal analyses of neuroimaging data

    Energy Technology Data Exchange (ETDEWEB)

    Salami, Alireza

    2012-07-01

    various cognitive questions. These methods are used in order to extract features that are inaccessible using univariate / unimodal analytic approaches. To this end, I implemented multivariate partial least squares analysis in study I and II in order to identify neural commonalities and differences between the available and accessible information in memory (study I), and also between episodic encoding and episodic retrieval (study II). Study I provided evidence of a qualitative differences between availability and accessibility signals in memory by linking memory access to modality-independent brain regions, and availability in memory to elevated activity in modality-specific brain regions. Study II provided evidence in support of general and specific memory operations during encoding and retrieval by linking general processes to the joint demands on attentional, executive, and strategic processing, and a process-specific network to core episodic memory function. In study II, III, and IV, I explored whether the age-related changes/differences in one modality were driven by age-related changes/differences in another modality. To this end, study II investigated whether age-related functional differences in hippocampus during an episodic memory task could be accounted for by age-related structural differences. I found that age-related local structural deterioration could partially but not entirely account for age-related diminished hippocampal activation. In study III, I sought to explore whether age-related changes in the prefrontal and occipital cortex during a semantic memory task were driven by local and/or distal gray matter loss. I found that age-related diminished prefrontal activation was driven, at least in part, by local gray matter atrophy, whereas the age-related decline in occipital cortex was accounted for by distal gray matter atrophy. Finally, in study IV, I investigated whether white matter (WM) microstructural differences mediated age-related decline in

  17. Multifractal analysis of sEMG signal of the complex muscle activity

    CERN Document Server

    Trybek, Paulina; Nowakowski, Michal; Machura, Lukasz

    2014-01-01

    The neuro--muscular activity while working on laparoscopic trainer is the example of the complex (and complicated) movement. This class of problems are still waiting for the proper theory which will be able to describe the actual properties of the muscle performance. Here we consider the signals obtained from three states of muscle activity: at maximum contraction, during complex movements (at actual work) and in the completely relaxed state. In addition the difference between a professional and an amateur is presented. The Multifractal Detrended Fluctuation Analysis was used in description of the properties the kinesiological surface electromyographic signals (sEMG). We demonstrate the dissimilarity between each state of work for the selected group of muscles as well as between trained and untrained individuals.

  18. Direct Modulation of Heterotrimeric G Protein-coupled Signaling by a Receptor Kinase Complex.

    Science.gov (United States)

    Tunc-Ozdemir, Meral; Urano, Daisuke; Jaiswal, Dinesh Kumar; Clouse, Steven D; Jones, Alan M

    2016-07-01

    Plants and some protists have heterotrimeric G protein complexes that activate spontaneously without canonical G protein-coupled receptors (GPCRs). In Arabidopsis, the sole 7-transmembrane regulator of G protein signaling 1 (AtRGS1) modulates the G protein complex by keeping it in the resting state (GDP-bound). However, it remains unknown how a myriad of biological responses is achieved with a single G protein modulator. We propose that in complete contrast to G protein activation in animals, plant leucine-rich repeat receptor-like kinases (LRR RLKs), not GPCRs, provide this discrimination through phosphorylation of AtRGS1 in a ligand-dependent manner. G protein signaling is directly activated by the pathogen-associated molecular pattern flagellin peptide 22 through its LRR RLK, FLS2, and co-receptor BAK1. PMID:27235398

  19. Increased Signal Complexity Improves the Breadth of Generalization in Auditory Perceptual Learning

    OpenAIRE

    Brown, David J.; Proulx, Michael J.

    2013-01-01

    Perceptual learning can be specific to a trained stimulus or optimally generalized to novel stimuli with the breadth of generalization being imperative for how we structure perceptual training programs. Adapting an established auditory interval discrimination paradigm to utilise complex signals, we trained human adults on a standard interval for either 2, 4, or 10 days. We then tested the standard, alternate frequency, interval, and stereo input conditions to evaluate the rapidity of specifi...

  20. The afferent signaling complex: Regulation of type I spiral ganglion neuron responses in the auditory periphery.

    Science.gov (United States)

    Reijntjes, Daniël O J; Pyott, Sonja J

    2016-06-01

    The spiral ganglion neurons (SGNs) are the first action potential generating neurons in the auditory pathway. The type I SGNs contact the sensory inner hair cells via their peripheral dendrites and relay auditory information to the brainstem via their central axon fibers. Individual afferent fibers show differences in response properties that are essential for normal hearing. The mechanisms that give rise to the heterogeneity of afferent responses are very poorly understood but are likely already in place at the peripheral dendrites where synapses are formed and action potentials are generated. To identify these molecular mechanisms, this review synthesizes a variety of literature and comprehensively outlines the cellular and molecular components positioned to regulate SGN afferent dendrite excitability, especially following glutamate release. These components include 1) proteins of the SGN postsynapses and neighboring supporting cells that together shape glutamatergic signaling, 2) the ion channels and transporters that determine the intrinsic excitability of the SGN afferent dendrites, and 3) the neurotransmitter receptors that extrinsically modify this excitability via synaptic input from the lateral olivocochlear efferents. This cellular and molecular machinery, together with presynaptic specializations of the inner hair cells, can be collectively referred to as the type I afferent signaling complex. As this review underscores, interactions of this signaling complex determine excitability of the SGN afferent dendrites and the afferent fiber responses. Moreover, this complex establishes the environmental milieu critical for the development and maintenance of the SGN afferent dendrites and synapses. Motivated by these important functions, this review also indicates areas of future research to elucidate the contributions of the afferent signaling complex to both normal hearing and also hearing loss. PMID:27018296

  1. Therapeutic targeting of the focal adhesion complex prevents oncogenic TGF-β signaling and metastasis

    OpenAIRE

    Wendt, Michael K.; William P. Schiemann

    2009-01-01

    Introduction Mammary tumorigenesis is associated with the increased expression of several proteins in the focal adhesion complex, including focal adhesion kinase (FAK) and various integrins. Aberrant expression of these molecules occurs concomitant with the conversion of TGF-β function from a tumor suppressor to a tumor promoter. We previously showed that interaction between β3 integrin and TβR-II facilitates TGF-β-mediated oncogenic signaling, epithelial-mesenchymal transition (EMT), and met...

  2. Signals Analysis and Clinical Validation of Blood and Oxygen Data in Human Brain

    Institute of Scientific and Technical Information of China (English)

    LI Kai-yang; LIU Li-jun; WANG Xiang; QIN Zhao; XIE Ze-ping

    2005-01-01

    With a self-made near-infrared analytical instrument to blood and oxygen parameters in human brain, 80 cases in which 20 are healthy persons and 30are anaesthetised cases and others are patients with heart function lack is taken to examine, and the data of blood and oxygen in brain tissue were collected and analyzed by the method of power spectrum and correlation function. The results indicate that: (1) The average brain oxygen saturation of healthy persons and anaesthetised cases is about 80%, in accord with normal parameter of physiology. Contrastively, the average brain oxygen saturation of patients with heart function lack is 72. 8%, which is obviously less than that of healthy persons and anaesthetised cases. The probability of medical statistics is less than 0. 01. (2) The shapes of wave of brain blood and oxygen for the healthy person and the anaesthetised case reveal small periodical fluctuations with stable shape and base line, and the trend of increase or decrease of blood and oxygen parameters in brain tissue is synchronous and a phase reversal, but for the patient with heart function lack in a brain oxygen lack state, the shapes of wave are irregular. This is a hint that near infrared light passing through tissue can reflect the intuitionistic change of brain blood and oxygen parameters. (3) The power spectra of brain blood and oxygen for the healthy person and the anaesthetised case has a clear main peak, narrow bandwidth and perfect superposition each other, but the power spectra for the patient with heart function lack in a brain oxygen lack state is on the contrary. (4) The average cross correlation coefficient of brain blood and oxygen for healthy persons and anaesthetised cases is -0. 9825±0. 1027 close to -1. But the average cross correlation coefficient for patients with heart function lack in a brain oxygen lack state is merely -0. 8923± 0. 1035 which is obviously greater than -1 and the probability of medical statistics is less than 0. 01

  3. Enterococcal Sex Pheromones: Evolutionary Pathways to Complex, Two-Signal Systems.

    Science.gov (United States)

    Dunny, Gary M; Berntsson, Ronnie Per-Arne

    2016-06-01

    Gram-positive bacteria carry out intercellular communication using secreted peptides. Important examples of this type of communication are the enterococcal sex pheromone systems, in which the transfer of conjugative plasmids is controlled by intercellular signaling among populations of donors and recipients. This review focuses on the pheromone response system of the conjugative plasmid pCF10. The peptide pheromones regulating pCF10 transfer act by modulating the ability of the PrgX transcription factor to repress the transcription of an operon encoding conjugation functions. Many Gram-positive bacteria regulate important processes, including the production of virulence factors, biofilm formation, sporulation, and genetic exchange using peptide-mediated signaling systems. The key master regulators of these systems comprise the RRNPP (RggRap/NprR/PlcR/PrgX) family of intracellular peptide receptors; these regulators show conserved structures. While many RRNPP systems include a core module of two linked genes encoding the regulatory protein and its cognate signaling peptide, the enterococcal sex pheromone plasmids have evolved to a complex system that also recognizes a second host-encoded signaling peptide. Additional regulatory genes not found in most RRNPP systems also modulate signal production and signal import in the enterococcal pheromone plasmids. This review summarizes several structural studies that cumulatively demonstrate that the ability of three pCF10 regulatory proteins to recognize the same 7-amino-acid pheromone peptide arose by convergent evolution of unrelated proteins from different families. We also focus on the selective pressures and structure/function constraints that have driven the evolution of pCF10 from a simple, single-peptide system resembling current RRNPPs in other bacteria to the current complex inducible plasmid transfer system. PMID:27021562

  4. Receiver discriminability drives the evolution of complex sexual signals by sexual selection.

    Science.gov (United States)

    Cui, Jianguo; Song, Xiaowei; Zhu, Bicheng; Fang, Guangzhan; Tang, Yezhong; Ryan, Michael J

    2016-04-01

    A hallmark of sexual selection by mate choice is the evolution of exaggerated traits, such as longer tails in birds and more acoustic components in the calls of birds and frogs. Trait elaboration can be opposed by costs such as increased metabolism and greater predation risk, but cognitive processes of the receiver can also put a brake on trait elaboration. For example, according to Weber's Law traits of a fixed absolute difference will be more difficult to discriminate as the absolute magnitude increases. Here, we show that in the Emei music frog (Babina daunchina) increases in the fundamental frequency between successive notes in the male advertisement call, which increases the spectral complexity of the call, facilitates the female's ability to compare the number of notes between calls. These results suggest that female's discriminability provides the impetus to switch from enhancement of signaling magnitude (i.e., adding more notes into calls) to employing a new signal feature (i.e., increasing frequency among notes) to increase complexity. We suggest that increasing the spectral complexity of notes ameliorates some of the effects of Weber's Law, and highlights how perceptual and cognitive biases of choosers can have important influences on the evolution of courtship signals. PMID:26920078

  5. Compound Heterozygosity for Mutations in PAX6 in Patient with Complex Brain Anomaly, Neonatal Diabetes Mellitus, and Microophthalmia

    OpenAIRE

    Solomon, Benjamin D.; Pineda-Alvarez, Daniel E.; Balog, Joan Z.; Hadley, Donald; Gropman, Andrea L.; Nandagopal, Radha; Han, Joan C.; Hahn, Jin S; BLAIN, DELPHINE; Brooks, Brian; Muenke, Maximilian

    2009-01-01

    We report on a patient with trisomy 21, microophthalmia, neonatal diabetes mellitus, hypopituitarism, and a complex structural brain anomaly who was a member of a large bilineal family with eye anomalies. The patient inherited a different mutation in PAX6 from each parent and is the only known living and second reported patient with compound heterozygosity for mutations in PAX6. PAX6 is a transcription factor involved in eye and brain development, and has roles in pancreatic and pituitary dev...

  6. Inhibition of IL-6 trans-signaling in the brain increases sociability in the BTBR mouse model of autism.

    Science.gov (United States)

    Wei, Hongen; Ma, Yuehong; Liu, Jianrong; Ding, Caiyun; Jin, Guorong; Wang, Yi; Hu, Fengyun; Yu, Li

    2016-10-01

    Autism is a severe neurodevelopmental disorder with a large population prevalence, characterized by abnormal reciprocal social interactions, communication deficits, and repetitive behaviors with restricted interests. The BTBR T(+)Itpr3(tf) (BTBR) mice have emerged as strong candidates to serve as models of a range of autism-relevant behaviors. Increasing evidences suggest that interleukin (IL)-6, one of the most important neuroimmune factors, was involved in the pathophysiology of autism. It is of great importance to further investigate whether therapeutic interventions in autism can be achieved through the manipulation of IL-6. Our previous studies showed that IL-6 elevation in the brain could mediate autistic-like behaviors, possibly through the imbalances of neural circuitry and impairments of synaptic plasticity. In this study, we evaluate whether inhibiting IL-6 signaling in the brain is sufficient to modulate the autism-like behaviors on the BTBR mice. The results showed that chronic infusion of an analog of the endogenous IL-6 trans-signaling blocker sgp130Fc protein increased the sociability in BTBR mice. Furthermore, no change was observed in the number of excitatory synapse, level of synaptic proteins, density of dentitic spine and postsynaptic density in BTBR cortices after inhibiting IL-6 trans-signaling. However, inhibition of IL-6 trans-signaling increased the evoked glutamate release in synaptoneurosomes from the cerebral cortex of BTBR mice. Our findings suggest that inhibition of excessive production of IL-6 may have selective therapeutic efficacy in treating abnormal social behaviors in autism. PMID:27460706

  7. Dynamic characteristics of oxygenation-sensitive MRI signal in different temporal protocols for imaging human brain activity

    International Nuclear Information System (INIS)

    The temporal characteristics of cerebral blood oxygenation during human brain activation were monitored with dynamic echo-planar imaging (EPI) using the blood oxygenation level dependent (BOLD) fMRI. We investigated oxygenation-sensitive signal changes: 1. during repetitive block stimuli, to determine the latency of the activation-induced signal change in the primary visual cortex; 2. on shortening the rest periods between constant stimulated phases, to investigate the limitations that this latency poses in temporal resolution of the technique; and 3. on sustained steady-state stimulation, to characterise oxygenation changes during prolonged brain activation using different stimuli. Delayed intrinsic haemodynamic response and a finite signal-to-noise ratio limit the temporal resolution achieved with BOLD fMRI. Separate activation periods were resolved when the delay between consecutive stimulations was at least 2 s. In this study oxygenation remained elevated throughout sustained activation, suggesting a constant rate of oxygen consumption by the primary cortical neurones during activation. Characterisation of fMRI signal dynamics in dynamic temporal protocols is significant both in terms of optimising stimulation protocols and the potential to gain insight into the physiological mechanisms underlying neuronal activation which could increase the clinical applicability of the technique. (orig.)

  8. TOR Complex 2-Ypk1 Signaling Maintains Sphingolipid Homeostasis by Sensing and Regulating ROS Accumulation

    Directory of Open Access Journals (Sweden)

    Brad J. Niles

    2014-02-01

    Full Text Available Reactive oxygen species (ROS are produced during normal metabolism and can function as signaling molecules. However, ROS at elevated levels can damage cells. Here, we identify the conserved target of rapamycin complex 2 (TORC2/Ypk1 signaling module as an important regulator of ROS in the model eukaryotic organism, S. cerevisiae. We show that TORC2/Ypk1 suppresses ROS produced both by mitochondria as well as by nonmitochondrial sources, including changes in acidification of the vacuole. Furthermore, we link vacuole-related ROS to sphingolipids, essential components of cellular membranes, whose synthesis is also controlled by TORC2/Ypk1 signaling. In total, our data reveal that TORC2/Ypk1 act within a homeostatic feedback loop to maintain sphingolipid levels and that ROS are a critical regulatory signal within this system. Thus, ROS sensing and signaling by TORC2/Ypk1 play a central physiological role in sphingolipid biosynthesis and in the maintenance of cell growth and viability.

  9. Synthesis and evaluation of ether containing {sup 99m}Tc-nitrido dithiocarbamate complexes as brain perfusion imaging agent

    Energy Technology Data Exchange (ETDEWEB)

    Mallia, Madhava B. [Radiopharmaceuticals Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Mathur, Anupam [Medical and Biological Products Program, Board of Radiation and Isotope Technology, Mumbai 400094 (India); Subramanian, Suresh [Radiopharmaceuticals Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Banerjee, Sharmila [Radiopharmaceuticals Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Kothari, Kanchan [Radiopharmaceuticals Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Koiry, S.P. [TechnicalPhysics and Prototype Engineering Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Sarma, H.D. [Radiation Biology and Health Science Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Venkatesh, Meera [Radiopharmaceuticals Division, Bhabha Atomic Research Centre, Mumbai 400085 (India) and Medical and Biological Products Program, Board of Radiation and Isotope Technology, Mumbai 400094 (India)]. E-mail: meerav@apsara.barc.ernet.in

    2006-03-15

    In the present study, a series of {sup 99m}Tc-nitrido dithiocarbamate complexes containing ether linkages have been prepared and their brain perfusion characteristics studied. Two primary dithiocarbamates and two secondary dithiocarbamates were synthesized in >80% yield and were characterized by elemental analyses. The ligands were then labeled using a {sup 99m}Tc-nitrido intermediate, prepared from sodium pertechnetate using commercially available nitrido kit-vials, at a low ligand concentration of 0.1 mg. The prepared complexes were obtained in more than 95% yield and were characterized by paper electrophoresis and HPLC. All the complexes were found to be neutral and eluted out as a single species in HPLC. Biodistribution studies were carried out in normal Swiss mice. All the complexes showed uptake in the brain. {sup 99m}TcN complexes of secondary dithiocarbamates showed higher initial brain uptake (5 min p.i.) than their primary amine counterparts. However, all the complexes exhibited rapid washout from the brain.

  10. Synthesis and evaluation of ether containing 99mTc-nitrido dithiocarbamate complexes as brain perfusion imaging agent

    International Nuclear Information System (INIS)

    In the present study, a series of 99mTc-nitrido dithiocarbamate complexes containing ether linkages have been prepared and their brain perfusion characteristics studied. Two primary dithiocarbamates and two secondary dithiocarbamates were synthesized in >80% yield and were characterized by elemental analyses. The ligands were then labeled using a 99mTc-nitrido intermediate, prepared from sodium pertechnetate using commercially available nitrido kit-vials, at a low ligand concentration of 0.1 mg. The prepared complexes were obtained in more than 95% yield and were characterized by paper electrophoresis and HPLC. All the complexes were found to be neutral and eluted out as a single species in HPLC. Biodistribution studies were carried out in normal Swiss mice. All the complexes showed uptake in the brain. 99mTcN complexes of secondary dithiocarbamates showed higher initial brain uptake (5 min p.i.) than their primary amine counterparts. However, all the complexes exhibited rapid washout from the brain

  11. Small and neutral TcvO BAT, bisaminoethanethiol (N2S2) complexes for developing new brain imaging agents

    International Nuclear Information System (INIS)

    Bisaminoethanethiol (BAT) ligands with various gem-dimethyl and amide groups were prepared, and the corresponding neutral Tc-99m complexes were prepared and evaluated for their relative stabilities by ligand-exchange reactions. It was demonstrated that technetium complexes containing gem-dimethyl substituents have higher lipophilicities, whereas those with an amide group possess greater stability, which enhances ligand-exchange reaction. The most interesting observation was that the brain uptake in rats is not determined only by lipophilicity. Apparently, Tc-99m complexes with an amide functional group display lower brain uptakes in rats compared to those without an amide group. The brain uptake was strongly influenced by substituents on the BAT ligand. These factors are critically important and should be taken into consideration when designing Tc-99m-labeled agents for CNS receptor imaging

  12. Evaluation of brain metabolite in patients with complex regional pain syndrome by MR spectroscopy

    International Nuclear Information System (INIS)

    Recently brain imaging studies have shown that patients with chronic pain have an altered cortical processing of nociceptive inputs. We evaluated brain metabolites in patients with complex regional pain syndrome (CRPS) using MR spectroscopy. Absolute concentrations of N-acetylaspartate (NAA) and choline (Cho) were measured in anterior cingulate (ACC) and prefrontal cortices (PFC) of patients and volunteers as matched control. Psychological aspects of patients were also evaluated with Hospital Anxiety and Depression (HAD) scale, in addition to the intensity of pain by visual analog scale. In the ACC, CRPS patients had a significant decrease of NAA and a significant increase of Cho compared to the control. Furthermore, patients with anxiety scored by HAD scale had reduced NAA concentration in ACC compared to the patients without anxiety. In the PFC, there was a reduction of NAA in the patients compared with that in control. No correlation was observed between intensity of pain and these metabolites. These results suggest that metabolite changes in ACC and PFC could reflect the pathogenesis of CRPS. (author)

  13. Dual-Tree Complex Wavelet Transform and Twin Support Vector Machine for Pathological Brain Detection

    Directory of Open Access Journals (Sweden)

    Shuihua Wang

    2016-06-01

    Full Text Available (Aim Classification of brain images as pathological or healthy case is a key pre-clinical step for potential patients. Manual classification is irreproducible and unreliable. In this study, we aim to develop an automatic classification system of brain images in magnetic resonance imaging (MRI. (Method Three datasets were downloaded from the Internet. Those images are of T2-weighted along axial plane with size of 256 × 256. We utilized an s-level decomposition on the basis of dual-tree complex wavelet transform (DTCWT, in order to obtain 12s “variance and entropy (VE” features from each subband. Afterwards, we used support vector machine (SVM and its two variants: the generalized eigenvalue proximal SVM (GEPSVM and the twin SVM (TSVM, as the classifiers. In all, we proposed three novel approaches: DTCWT + VE + SVM, DTCWT + VE + GEPSVM, and DTCWT + VE + TSVM. (Results The results showed that our “DTCWT + VE + TSVM” obtained an average accuracy of 99.57%, which was not only better than the two other proposed methods, but also superior to 12 state-of-the-art approaches. In addition, parameter estimation showed the classification accuracy achieved the largest when the decomposition level s was assigned with a value of 1. Further, we used 100 slices from real subjects, and we found our proposed method was superior to human reports from neuroradiologists. (Conclusions This proposed system is effective and feasible.

  14. Structural bases for neurophysiological investigations of amygdaloid complex of the brain

    Science.gov (United States)

    Kalimullina, Liliya B.; Kalkamanov, Kh. A.; Akhmadeev, Azat V.; Zakharov, Vadim P.; Sharafullin, Ildus F.

    2015-11-01

    Amygdala (Am) as a part of limbic system of the brain defines such important functions as adaptive behavior of animals, formation of emotions and memory, regulation of endocrine and visceral functions. We worked out, with the help of mathematic modelling of the pattern recognition theory, principles for organization of neurophysiological and neuromorphological studies of Am nuclei, which take into account the existing heterogeneity of its formations and optimize, to a great extent, the protocol for carrying out of such investigations. The given scheme of studies of Am’s structural-functional organization at its highly-informative sections can be used as a guide for precise placement of electrodes’, cannulae’s and microsensors into particular Am nucleus in the brain with the registration not only the nucleus itself, but also its extensions. This information is also important for defining the number of slices covering specific Am nuclei which must be investigated to reveal the physiological role of a particular part of amygdaloid complex.

  15. Active site coupling in PDE:PKA complexes promotes resetting of mammalian cAMP signaling.

    Science.gov (United States)

    Krishnamurthy, Srinath; Moorthy, Balakrishnan Shenbaga; Xin Xiang, Lim; Xin Shan, Lim; Bharatham, Kavitha; Tulsian, Nikhil Kumar; Mihalek, Ivana; Anand, Ganesh S

    2014-09-16

    Cyclic 3'5' adenosine monophosphate (cAMP)-dependent-protein kinase (PKA) signaling is a fundamental regulatory pathway for mediating cellular responses to hormonal stimuli. The pathway is activated by high-affinity association of cAMP with the regulatory subunit of PKA and signal termination is achieved upon cAMP dissociation from PKA. Although steps in the activation phase are well understood, little is known on how signal termination/resetting occurs. Due to the high affinity of cAMP to PKA (KD ∼ low nM), bound cAMP does not readily dissociate from PKA, thus begging the question of how tightly bound cAMP is released from PKA to reset its signaling state to respond to subsequent stimuli. It has been recently shown that phosphodiesterases (PDEs) can catalyze dissociation of bound cAMP and thereby play an active role in cAMP signal desensitization/termination. This is achieved through direct interactions with the regulatory subunit of PKA, thereby facilitating cAMP dissociation and hydrolysis. In this study, we have mapped direct interactions between a specific cyclic nucleotide phosphodiesterase (PDE8A) and a PKA regulatory subunit (RIα isoform) in mammalian cAMP signaling, by a combination of amide hydrogen/deuterium exchange mass spectrometry, peptide array, and computational docking. The interaction interface of the PDE8A:RIα complex, probed by peptide array and hydrogen/deuterium exchange mass spectrometry, brings together regions spanning the phosphodiesterase active site and cAMP-binding sites of RIα. Computational docking combined with amide hydrogen/deuterium exchange mass spectrometry provided a model for parallel dissociation of bound cAMP from the two tandem cAMP-binding domains of RIα. Active site coupling suggests a role for substrate channeling in the PDE-dependent dissociation and hydrolysis of cAMP bound to PKA. This is the first instance, to our knowledge, of PDEs directly interacting with a cAMP-receptor protein in a mammalian system, and

  16. Deep Brain Stimulation: More Complex than the Inhibition of Cells and Excitation of Fibers.

    Science.gov (United States)

    Florence, Gerson; Sameshima, Koichi; Fonoff, Erich T; Hamani, Clement

    2016-08-01

    High-frequency deep brain stimulation (DBS) is an effective treatment for some movement disorders. Though mechanisms underlying DBS are still unclear, commonly accepted theories include a "functional inhibition" of neuronal cell bodies and the excitation of axonal projections near the electrodes. It is becoming clear, however, that the paradoxical dissociation "local inhibition" and "distant excitation" is far more complex than initially thought. Despite an initial increase in neuronal activity following stimulation, cells are often unable to maintain normal ionic concentrations, particularly those of sodium and potassium. Based on currently available evidence, we proposed an alternative hypothesis. Increased extracellular concentrations of potassium during DBS may change the dynamics of both cells and axons, contributing not only to the intermittent excitation and inhibition of these elements but also to interrupt abnormal pathological activity. In this article, we review mechanisms through which high extracellular potassium may mediate some of the effects of DBS. PMID:26150316

  17. The locust standard brain: a 3D standard of the central complex as a platform for neural network analysis

    Directory of Open Access Journals (Sweden)

    Stanley Heinze

    2010-02-01

    Full Text Available Many insects use the pattern of polarized light in the sky for spatial orientation and navigation. We have investigated the polarization vision system in the desert locust. To create a common platform for anatomical studies on polarization vision pathways, Kurylas et al. (2008 have generated a three-dimensional (3D standard brain from confocal microscopy image stacks of 10 male brains, using two different standardization methods, the Iterative Shape Averaging (ISA procedure and the Virtual Insect Brain (VIB protocol. Comparison of both standardization methods showed that the VIB standard is ideal for comparative volume analysis of neuropils, whereas the ISA standard is the method of choice to analyze the morphology and connectivity of neurons. The central complex is a key processing stage for polarization information in the locust brain. To investigate neuronal connections between diverse central-complex neurons, we generated a higher-resolution standard atlas of the central complex and surrounding areas, using the ISA method based on brain sections from 20 individual central complexes. To explore the usefulness of this atlas, two central-complex neurons, a polarization-sensitive columnar neuron (type CPU1a and a tangential neuron that is activated during flight, the giant-fan shaped (GFS neuron, were reconstructed three-dimensionally from brain sections. To examine whether the GFS neuron is a candidate to contribute to synaptic input to the CPU1a neuron, we registered both neurons into the standardized central complex. Visualization of both neurons revealed a potential connection of the CPU1a and GFS neurons in layer II of the upper division of the central body.

  18. Efficient physical embedding of topologically complex information processing networks in brains and computer circuits.

    Directory of Open Access Journals (Sweden)

    Danielle S Bassett

    2010-04-01

    Full Text Available Nervous systems are information processing networks that evolved by natural selection, whereas very large scale integrated (VLSI computer circuits have evolved by commercially driven technology development. Here we follow historic intuition that all physical information processing systems will share key organizational properties, such as modularity, that generally confer adaptivity of function. It has long been observed that modular VLSI circuits demonstrate an isometric scaling relationship between the number of processing elements and the number of connections, known as Rent's rule, which is related to the dimensionality of the circuit's interconnect topology and its logical capacity. We show that human brain structural networks, and the nervous system of the nematode C. elegans, also obey Rent's rule, and exhibit some degree of hierarchical modularity. We further show that the estimated Rent exponent of human brain networks, derived from MRI data, can explain the allometric scaling relations between gray and white matter volumes across a wide range of mammalian species, again suggesting that these principles of nervous system design are highly conserved. For each of these fractal modular networks, the dimensionality of the interconnect topology was greater than the 2 or 3 Euclidean dimensions of the space in which it was embedded. This relatively high complexity entailed extra cost in physical wiring: although all networks were economically or cost-efficiently wired they did not strictly minimize wiring costs. Artificial and biological information processing systems both may evolve to optimize a trade-off between physical cost and topological complexity, resulting in the emergence of homologous principles of economical, fractal and modular design across many different kinds of nervous and computational networks.

  19. Inhibition of cerebral vascular inflammation by brain endothelium-targeted oligodeoxynucleotide complex.

    Science.gov (United States)

    Hu, Jing; Al-Waili, Daniah; Hassan, Aishlin; Fan, Guo-Chang; Xin, Mei; Hao, Jiukuan

    2016-08-01

    The present study generated a novel DNA complex to specifically target endothelial NF-κB to inhibit cerebral vascular inflammation. This DNA complex (GS24-NFκB) contains a DNA decoy which inhibits NF-κB activity, and a DNA aptamer (GS-24), a ligand of transferrin receptor (TfR), which allows for targeted delivery of the DNA decoy into cells. The results indicate that GS24-NFκB was successfully delivered into a murine brain-derived endothelial cell line, bEND5, and inhibited inflammatory responses induced by tumor necrosis factor α (TNF-α) or oxygen-glucose deprivation/re-oxygenation (OGD/R) via down-regulation of the nuclear NF-κB subunit, p65, as well as its downstream inflammatory cytokines, inter-cellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule (VCAM-1). The inhibitory effect of the GS24-NFκB was demonstrated by a significant reduction in TNF-α or OGD/R induced monocyte adhesion to the bEND5 cells after GS24-NFκB treatment. Intravenous (i.v.) injection of GS24-'NFκB (15mg/kg) was able to inhibit the levels of phoseph-p65 and VCAM-1 in brain endothelial cells in a mouse lipopolysaccharide (LPS)-induced inflammatory model in vivo. In conclusion, our approach using DNA nanotechnology for DNA decoy delivery could potentially be utilized for inhibition of inflammation in ischemic stroke and other neuro-inflammatory diseases affecting cerebral vasculature. PMID:27132231

  20. Cinnamon counteracts the negative effects of a high fat/high fructose diet on behavior, brain insulin signaling and Alzheimer-associated changes

    Science.gov (United States)

    Insulin resistance leads to memory impairment. Cinnamon (CN) improves whole body insulin resistance but its effects in the brain are not known. Changes in behavior, insulin signaling, and Alzheimer-associated gene expression in the brain were measured in male Wistar rats fed a high fat/high fructose...

  1. Demonstration of brain noise on human EEG signals in perception of bistable images

    Science.gov (United States)

    Grubov, Vadim V.; Runnova, Anastasiya E.; Kurovskaya, Maria K.; Pavlov, Alexey N.; Koronovskii, Alexey A.; Hramov, Alexander E.

    2016-03-01

    In this report we studied human brain activity in the case of bistable visual perception. We proposed a new approach for quantitative characterization of this activity based on analysis of EEG oscillatory patterns and evoked potentials. Accordingly to theoretical background, obtained experimental EEG data and results of its analysis we studied a characteristics of brain activity during decision-making. Also we have shown that decisionmaking process has the special patterns on the EEG data.

  2. Butylphthalide Suppresses Neuronal Cells Apoptosis and Inhibits JNK-Caspase3 Signaling Pathway After Brain Ischemia /Reperfusion in Rats.

    Science.gov (United States)

    Wen, Xiang-Ru; Tang, Man; Qi, Da-Shi; Huang, Xiao-Jing; Liu, Hong-Zhi; Zhang, Fang; Wu, Jian; Wang, Yi-Wen; Zhang, Xun-Bao; Guo, Ji-Qiang; Wang, Shu-Ling; Liu, Yong; Wang, Yu-Lan; Song, Yuan-Jian

    2016-10-01

    Although Butylphthalide (BP) has protective effects that reduce ischemia-induced brain damage and neuronal cell death, little is known about the precise mechanisms occurring during cerebral ischemia/reperfusion (I/R). Therefore, the aim of this study was to investigate the neuroprotective mechanisms of BP against ischemic brain injury induced by cerebral I/R through inhibition of the c-Jun N-terminal kinase (JNK)-Caspase3 signaling pathway. BP in distilled non-genetically modified Soybean oil was administered intragastrically three times a day at a dosage of 15 mg/(kg day) beginning at 20 min after I/R in Sprague-Dawley rats. Immunohistochemical staining and Western blotting were performed to examine the expression of related proteins, and TUNEL-staining was used to detect the percentage of neuronal apoptosis in the hippocampal CA1 region. The results showed that BP could significantly protect neurons against cerebral I/R-induced damage. Furthermore, the expression of p-JNK, p-Bcl2, p-c-Jun, FasL, and cleaved-caspase3 was also decreased in the rats treated with BP. In summary, our results imply that BP could remarkably improve the survival of CA1 pyramidal neurons in I/R-induced brain injury and inhibit the JNK-Caspase3 signaling pathway. PMID:27015680

  3. Real-time estimation and detection of non-linearity in bio-signals using wireless brain-computer interface.

    Science.gov (United States)

    Ganesan, S; Victoire, T Aruldoss Albert; Vijayalakshmy, G

    2014-01-01

    In this paper, the work is mainly concentrated on removing non-linear parameters to make the physiological signals more linear and reducing the complexity of the signals. This paper discusses three different types of techniques that can be successfully utilised to remove non-linear parameters in EEG and ECG. (i) Transformation technique using Discrete Walsh-Hadamard Transform (DWHT); (ii) application of fuzzy logic control and (iii) building the Adaptive Neuro-Fuzzy Inference System (ANFIS) model for fuzzy. This work has been inspired by the need to arrive at an efficient, simple, accurate and quicker method for analysis of bio-signal. PMID:24589837

  4. Transport of receptors, receptor signaling complexes and ion channels via neuropeptide-secretory vesicles

    Institute of Scientific and Technical Information of China (English)

    Bo Zhao; Hai-Bo Wang; Ying-Jin Lu; Jian-Wen Hu; Lan Bao; Xu Zhang

    2011-01-01

    Stimulus-induced exocytosis of large dense-core vesicles(LDCVs)leads to discharge of neuropeptides and fusion of LDCV membranes with the plasma membrane. However, the contribution of LDCVs to the properties of the neuronal membrane remains largely unclear. The present study found that LDCVs were associated with multiple receptors, channels and signaling molecules, suggesting that neuronal sensitivity is modulated by an LDCV-mediated mechanism. Liquid chromatography-mass spectrometry combined with immunoblotting of subcellular fractions identified 298 proteins in LDCV membranes purified from the dorsal spinal cord, including Gprotein-coupled receptors, Gproteins and other signaling molecules, ion channels and trafficking-related proteins. Morphological assays showed that δ-opioid receptor 1(DORI), β2 adrenergic receptor(AR), Gα12,voltage-gated calcium channel a2δ1subunit and P2X purinoceptor 2 were localized in substance P(SP)-positive LDCVs in small-diameter dorsal root ganglion neurons, whereas β1 AR, Wnt receptor frizzled 8 and dishevelled 1 were present in SP-negative LDCVs.Furthermore, DOR1/α12/Gβ1γ5/phospholipase C β2 complexes were associated with LDCVs. Blockade of the DOR1/Gαi2 interaction largely abolished the LDCV localization of Gαi2 and impaired stimulation-induced surface expression of Gαi2. Thus, LDCVs serve as carriers of receptors, ion channels and preassembled receptor signaling complexes, enabling a rapid, activity-dependent modulation of neuronal sensitivity.

  5. Melatonin attenuated early brain injury induced by subarachnoid hemorrhage via regulating NLRP3 inflammasome and apoptosis signaling.

    Science.gov (United States)

    Dong, Yushu; Fan, Chongxi; Hu, Wei; Jiang, Shuai; Ma, Zhiqiang; Yan, Xiaolong; Deng, Chao; Di, Shouyin; Xin, Zhenlong; Wu, Guiling; Yang, Yang; Reiter, Russel J; Liang, Guobiao

    2016-04-01

    Subarachnoid hemorrhage (SAH) is a devastating condition with high morbidity and mortality rates due to the lack of effective therapy. Nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome activation associated with the upregulation of apoptotic signaling pathway has been implicated in various inflammatory diseases including hemorrhagic insults. Melatonin is reported to possess substantial anti-inflammatory properties, which is beneficial for early brain injury (EBI) after SAH. However, the molecular mechanisms have not been clearly identified. This study was designed to investigate the protective effects of melatonin against EBI induced by SAH and to elucidate the potential mechanisms. The adult mice were subjected to SAH. Melatonin or vehicle was injected intraperitoneally 2 hr after SAH. Melatonin was neuroprotective, as shown by increased survival rate, as well as elevated neurological score, greater survival of neurons, preserved brain glutathione levels, and reduced brain edema, malondialdehyde concentrations, apoptotic ratio, and blood-brain barrier (BBB) disruption. Melatonin also attenuated the expressions of NLRP3, apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), cleaved caspase-1, interleukin-1β (IL-1β), and interleukin-6 (IL-6); these changes were also associated with an increase in the anti-apoptotic factor (Bcl2) and reduction in the pro-apoptotic factor (Bim). In summary, our results demonstrate that melatonin treatment attenuates the EBI following SAH by inhibiting NLRP3 inflammasome-associated apoptosis. PMID:26639408

  6. A high-content imaging workflow to study Grb2 signaling complexes by expression cloning.

    Science.gov (United States)

    Freeman, Jamie; Kriston-Vizi, Janos; Seed, Brian; Ketteler, Robin

    2012-01-01

    Signal transduction by growth factor receptors is essential for cells to maintain proliferation and differentiation and requires tight control. Signal transduction is initiated by binding of an external ligand to a transmembrane receptor and activation of downstream signaling cascades. A key regulator of mitogenic signaling is Grb2, a modular protein composed of an internal SH2 (Src Homology 2) domain flanked by two SH3 domains that lacks enzymatic activity. Grb2 is constitutively associated with the GTPase Son-Of-Sevenless (SOS) via its N-terminal SH3 domain. The SH2 domain of Grb2 binds to growth factor receptors at phosphorylated tyrosine residues thus coupling receptor activation to the SOS-Ras-MAP kinase signaling cascade. In addition, other roles for Grb2 as a positive or negative regulator of signaling and receptor endocytosis have been described. The modular composition of Grb2 suggests that it can dock to a variety of receptors and transduce signals along a multitude of different pathways(1-3). Described here is a simple microscopy assay that monitors recruitment of Grb2 to the plasma membrane. It is adapted from an assay that measures changes in sub-cellular localization of green-fluorescent protein (GFP)-tagged Grb2 in response to a stimulus(4-6). Plasma membrane receptors that bind Grb2 such as activated Epidermal Growth Factor Receptor (EGFR) recruit GFP-Grb2 to the plasma membrane upon cDNA expression and subsequently relocate to endosomal compartments in the cell. In order to identify in vivo protein complexes of Grb2, this technique can be used to perform a genome-wide high-content screen based on changes in Grb2 sub-cellular localization. The preparation of cDNA expression clones, transfection and image acquisition are described in detail below. Compared to other genomic methods used to identify protein interaction partners, such as yeast-two-hybrid, this technique allows the visualization of protein complexes in mammalian cells at the sub

  7. Mass exponent spectrum analysis of human ECG signals and its application to complexity detection

    Science.gov (United States)

    Yang, Xiaodong; Du, Sidan; Ning, Xinbao; Bian, Chunhua

    2008-06-01

    The complexity of electrocardiogram (ECG) signal may reflect the physiological function and healthy status of the heart. In this paper, we introduced two novel intermediate parameters of multifractality, the mass exponent spectrum curvature and area, to characterize the nonlinear complexity of ECG signal. These indicators express the nonlinear superposition of the discrepancies of singularity strengths from all the adjacent points of the spectrum curve and thus overall subsets of original fractal structure. The evaluation of binomial multifractal sets validated these two variables were entirely effective in exploring the complexity of this time series. We then studied the ECG mass exponent spectra taken from the cohorts of healthy, ischemia and myocardial infarction (MI) sufferer based on a large sets of 12 leads’ recordings, and took the statistical averages among each crowd. Experimental results suggest the two values from healthy ECG are apparently larger than those from the heart diseased. While the values from ECG of MI sufferer are much smaller than those from the other two groups. As for the ischemia sufferer, they are almost of moderate magnitude. Afterward, we compared these new indicators with the nonlinear parameters of singularity spectrum. The classification indexes and results of total separating ratios (TSR, defined in the paper) both indicated that our method could achieve a better effect. These conclusions may be of some values in early diagnoses and clinical applications.

  8. HGF-MET signals via the MLL-ETS2 complex in hepatocellular carcinoma.

    Science.gov (United States)

    Takeda, Shugaku; Liu, Han; Sasagawa, Satoru; Dong, Yiyu; Trainor, Paul A; Cheng, Emily H; Hsieh, James J

    2013-07-01

    HGF signals through its cognate receptor, MET, to orchestrate diverse biological processes, including cell proliferation, cell fate specification, organogenesis, and epithelial-mesenchymal transition. Mixed-lineage leukemia (MLL), an epigenetic regulator, plays critical roles in cell fate, stem cell, and cell cycle decisions. Here, we describe a role for MLL in the HGF-MET signaling pathway. We found a shared phenotype among Mll(-/-), Hgf(-/-), and Met(-/-) mice with common cranial nerve XII (CNXII) outgrowth and myoblast migration defects. Phenotypic analysis demonstrated that MLL was required for HGF-induced invasion and metastatic growth of hepatocellular carcinoma cell lines. HGF-MET signaling resulted in the accumulation of ETS2, which interacted with MLL to transactivate MMP1 and MMP3. ChIP assays demonstrated that activation of the HGF-MET pathway resulted in increased occupancy of the MLL-ETS2 complex on MMP1 and MMP3 promoters, where MLL trimethylated histone H3 lysine 4 (H3K4), activating transcription. Our results present an epigenetic link between MLL and the HGF-MET signaling pathway, which may suggest new strategies for therapeutic intervention. PMID:23934123

  9. Estrogen treatment following severe burn injury reduces brain inflammation and apoptotic signaling

    Directory of Open Access Journals (Sweden)

    Idris Ahamed H

    2009-10-01

    Full Text Available Abstract Background Patients with severe burn injury experience a rapid elevation in multiple circulating pro-inflammatory cytokines, with the levels correlating with both injury severity and outcome. Accumulations of these cytokines in animal models have been observed in remote organs, however data are lacking regarding early brain cytokine levels following burn injury, and the effects of estradiol on these levels. Using an experimental animal model, we studied the acute effects of a full-thickness third degree burn on brain levels of TNF-α, IL-1β, and IL-6 and the protective effects of acute estrogen treatment on these levels. Additionally, the acute administration of estrogen on regulation of inflammatory and apoptotic events in the brain following severe burn injury were studied through measuring the levels of phospho-ERK, phospho-Akt, active caspase-3, and PARP cleavage in the placebo and estrogen treated groups. Methods In this study, 149 adult Sprague-Dawley male rats received 3rd degree 40% total body surface area (TBSA burns. Fifteen minutes following burn injury, the animals received a subcutaneous injection of either placebo (n = 72 or 17 beta-estradiol (n = 72. Brains were harvested at 0.5, 1, 2, 4, 6, 8, 12, 18, and 24 hours after injury from the control (n = 5, placebo (n = 8/time point, and estrogen treated animals (n = 8/time point. The brain cytokine levels were measured using the ELISA method. In addition, we assessed the levels of phosphorylated-ERK, phosphorylated-Akt, active caspase-3, and the levels of cleaved PARP at the 24 hour time-point using Western blot analysis. Results In burned rats, 17 beta-estradiol significantly decreased the levels of brain tissue TNF-α (~25%, IL-1β (~60%, and IL-6 (~90% when compared to the placebo group. In addition, we determined that in the estrogen-treated rats there was an increase in the levels of phospho-ERK (p p p p Conclusion Following severe burn injury, estrogens decrease both

  10. NONINVASIVE DETECTION OF BRAIN ACTIVITY VARIATION UNDER DIFFERENT DEPTH OF ANESTHESIA BY EEG COMPLEXITY

    Institute of Scientific and Technical Information of China (English)

    Xu Jin; Li Wenwen; Zheng Chongxun; Jing Guixia; Liu Xueliang

    2006-01-01

    Objective To detect the change of brain activity under different depth of anesthesia (DOA)noninvasively. Methods The Lempel-Ziv complexity C(n) was used to analyze EEG and its four components (delta,theta, alpha, beta), which was recorded from SD rats under different DOA. The relationship between C(n) and DOA was studied. Results The C(n) of EEG will decrease while the depth of anesthesia increasing and vice versa. It can be used to detect the change of DOA sensitively. Compared with power spectrum, the change of C(n) is opposite to that of power spectru,. Only the C(n) of delta rhythm has obvious variations induced by the change of DOA, and the variations of delta is as similar as the EEG's. Conclusion The study shows that the desynchronized EEG is replaced by the synchronized EEG when rat goes into anesthesia state from awake, that is just the reason why complexity and power spectrum appear corresponding changes under different DOA. C(n) of delta rhythm dynamic change leads to the change of EEG, and the delta rhythm is the dominant rhythm during anesthesia for rats.

  11. Nonessential Role for the NLRP1 Inflammasome Complex in a Murine Model of Traumatic Brain Injury

    Directory of Open Access Journals (Sweden)

    Thomas Brickler

    2016-01-01

    Full Text Available Traumatic brain injury (TBI elicits the immediate production of proinflammatory cytokines which participate in regulating the immune response. While the mechanisms of adaptive immunity in secondary injury are well characterized, the role of the innate response is unclear. Recently, the NLR inflammasome has been shown to become activated following TBI, causing processing and release of interleukin-1β (IL-1β. The inflammasome is a multiprotein complex consisting of nucleotide-binding domain and leucine-rich repeat containing proteins (NLR, caspase-1, and apoptosis-associated speck-like protein (ASC. ASC is upregulated after TBI and is critical in coupling the proteins during complex formation resulting in IL-1β cleavage. To directly test whether inflammasome activation contributes to acute TBI-induced damage, we assessed IL-1β, IL-18, and IL-6 expression, contusion volume, hippocampal cell death, and motor behavior recovery in Nlrp1−/−, Asc−/−, and wild type mice after moderate controlled cortical impact (CCI injury. Although IL-1β expression is significantly attenuated in the cortex of Nlrp1−/− and Asc−/− mice following CCI injury, no difference in motor recovery, cell death, or contusion volume is observed compared to wild type. These findings indicate that inflammasome activation does not significantly contribute to acute neural injury in the murine model of moderate CCI injury.

  12. Using ipsilateral motor signals in the unaffected cerebral hemisphere as a signal platform for brain-computer interfaces in hemiplegic stroke survivors

    Science.gov (United States)

    Bundy, David T.; Wronkiewicz, Mark; Sharma, Mohit; Moran, Daniel W.; Corbetta, Maurizio; Leuthardt, Eric C.

    2012-06-01

    Brain-computer interface (BCI) systems have emerged as a method to restore function and enhance communication in motor impaired patients. To date, this has been applied primarily to patients who have a compromised motor outflow due to spinal cord dysfunction, but an intact and functioning cerebral cortex. The cortical physiology associated with movement of the contralateral limb has typically been the signal substrate that has been used as a control signal. While this is an ideal control platform in patients with an intact motor cortex, these signals are lost after a hemispheric stroke. Thus, a different control signal is needed that could provide control capability for a patient with a hemiparetic limb. Previous studies have shown that there is a distinct cortical physiology associated with ipsilateral, or same-sided, limb movements. Thus far, it was unknown whether stroke survivors could intentionally and effectively modulate this ipsilateral motor activity from their unaffected hemisphere. Therefore, this study seeks to evaluate whether stroke survivors could effectively utilize ipsilateral motor activity from their unaffected hemisphere to achieve this BCI control. To investigate this possibility, electroencephalographic (EEG) signals were recorded from four chronic hemispheric stroke patients as they performed (or attempted to perform) real and imagined hand tasks using either their affected or unaffected hand. Following performance of the screening task, the ability of patients to utilize a BCI system was investigated during on-line control of a one-dimensional control task. Significant ipsilateral motor signals (associated with movement intentions of the affected hand) in the unaffected hemisphere, which were found to be distinct from rest and contralateral signals, were identified and subsequently used for a simple online BCI control task. We demonstrate here for the first time that EEG signals from the unaffected hemisphere, associated with overt and

  13. Features of adult neurogenesis and neurochemical signaling in the Cherry salmon Oncorhynchus masou brain

    Institute of Scientific and Technical Information of China (English)

    Evgeniya V. Pushchina; Dmitry K. Оbukhov; Anatoly A. Varaksin

    2013-01-01

    We investigated the distribution of gamma aminobutyric acid, tyrosine hydroxylase and nitric oxide-producing elements in a cherry salmon Oncorhynchus masou brain at various stages of postnatal ontogenesis by immunohistochemical staining and histochemical staining. The periventricular region cells exhibited the morphology of neurons and glia including radial glia-like cells and contained several neurochemical substances. Heterogeneous populations of tyrosine dinucleotide phosphate diaphorase-positive cells were observed in proliferating cell nuclear antigen-immunoreactive proliferative zones in periventricular area of diencephalon, central grey layer of dorsomedial tegmentum, medulla and spinal cord. Immunolocalization of Pax6 in the cherry salmon brain revealed a neuromeric construction of the brain at various stages of postnatal ontogenesis, and this was confirmed by tyrosine hydroxylase and gamma aminobutyric acid labeling.

  14. Modeling Transitions in Complex Systems by Multiplicative Effect of Temporal Patterns Extracted from Signal Flows

    Directory of Open Access Journals (Sweden)

    Ezzat G. Bakhoum

    2012-01-01

    for characterizing suddenly emerging phenomena as nonlinear transitions. Newly created temporal patterns extracted from internal signal flow (mathematically represented as oscillations with long period interact as new entities in a multiplicative manner with subsequent pulses from the external time series (already existing entities in order to generate nonlinear transitions within the system. Such effects are enhanced when the period of external pulses creating new patterns is similar to the settling time of the complex system (this being the condition for an efficient external action. For complex systems where both classical and quantum phenomena generated by external time series are involved, this mathematical model can correctly explain the transition from classical to quantum behaviour (corresponding to a more ordered structure avoiding typical contradictions generated by analysis performed on transient time intervals or by wave superposition.

  15. Chromogenic signaling of water traces by 1,8-naphthalohydrazone-anion complex in organic solvents

    Directory of Open Access Journals (Sweden)

    Veikko Uahengo

    2016-06-01

    Full Text Available A naphthalo-1, 8-bis[(2,4-dinitrophenylhydrazone] sensor (K was synthesized and characterized using UV–vis, 1H NMR and fluorescence spectroscopy. The sensor showed strong colorimetric and spectral response upon the molar addition of acetate or fluoride ion (AcO− or F− in acetonitrile. The complexed state (KF or KAcO of the system showed significant reversibility properties, both in color and spectra, upon the addition of small traces of water. Subsequently, in addition to sensing of fluoride or acetate ions, the complexed KF or KAcO adducts can be used in colorimetric signaling of water traces in different organic mediums. In order to have more understanding of the interaction between K and the anions, the study was supplemented using density functional theory computations.

  16. Alterations in brain leptin signalling in spite of unchanged CSF leptin levels in Alzheimer’s disease

    OpenAIRE

    S. MAIOLI; Lodeiro, M. (María); Merino-Serrais, P.; Falahati, F.; Khan, W.; Puerta, E. (Elena); Codita, A. (Alina); Rimondini, R.; Ramirez, M.J. (María Javier); Simmons, A.; Gil-Bea, F J; Westman, E.; Cedazo-Minguez, A.

    2014-01-01

    Several studies support the relation between leptin and Alzheimer’s disease (AD). We show that leptin levels in CSF are unchanged as subjects progress to AD. However, in AD hippocampus, leptin signalling was decreased and leptin localization was shifted, being more abundant in reactive astrocytes and less in neurons. Similar translocation of leptin was found in brains from Tg2576 and apoE4 mice. Moreover, an enhancement of leptin receptors was found in hippocampus of young Tg2576 mice and in ...

  17. Comparison of Classifiers and Statistical Analysis for EEG Signals Used in Brain Computer Interface Motor Task Paradigm

    Directory of Open Access Journals (Sweden)

    Oana Diana Eva

    2015-01-01

    Full Text Available Using the EEG Motor Movement/Imagery database there is proposed an off-line analysis for a brain computer interface (BCI paradigm. The purpose of the quantitative research is to compare classifiers in order to determinate which of them has highest rates of classification. The power spectral density method is used to evaluated the (desynchronizations that appear on Mu rhythm. The features extracted from EEG signals are classified using linear discriminant classifier (LDA, quadratic classifier (QDA and classifier based on Mahalanobis distance (MD. The differences between LDA, QDA and MD are small, but the superiority of QDA was sustained by analysis of variance (ANOVA.

  18. Music Composition from the Brain Signal: Representing the Mental State by Music

    OpenAIRE

    Dan Wu; Chaoyi Li; Yu Yin; Changzheng Zhou; Dezhong Yao

    2010-01-01

    This paper proposes a method to translate human EEG into music, so as to represent mental state by music. The arousal levels of the brain mental state and music emotion are implicitly used as the bridge between the mind world and the music. The arousal level of the brain is based on the EEG features extracted mainly by wavelet analysis, and the music arousal level is related to the musical parameters such as pitch, tempo, rhythm, and tonality. While composing, some music principles (harmonics...

  19. Resting and Task-Modulated High-Frequency Brain Rhythms Measured by Scalp Encephalography in Infants with Tuberous Sclerosis Complex

    Science.gov (United States)

    Stamoulis, Catherine; Vogel-Farley, Vanessa; Degregorio, Geneva; Jeste, Shafali S.; Nelson, Charles A.

    2015-01-01

    The electrophysiological correlates of cognitive deficits in tuberous sclerosis complex (TSC) are not well understood, and modulations of neural dynamics by neuroanatomical abnormalities that characterize the disorder remain elusive. Neural oscillations (rhythms) are a fundamental aspect of brain function, and have dominant frequencies in a wide…

  20. Reversible brain atrophy and subcortical high signal on MRI in a patient with anorexia nervosa

    International Nuclear Information System (INIS)

    Anorexia nervosa (AN), usually seen in young girls, is characterised by severe emaciation induced by self-imposed starvation. Enlargement of the ventricular system and sulci has been reported, as has high signal on T2-weighted images. We present a case with atrophic changes and high signal on T2-weighted images, which resolved completely following weight gain. (orig.)

  1. Reversible brain atrophy and subcortical high signal on MRI in a patient with anorexia nervosa

    Energy Technology Data Exchange (ETDEWEB)

    Drevelengas, A. [Asklipios-Aristotelio Diagnostic Centre, Thessaloniki (Greece); Dept. of Radiology, AHEPA University Hospital, Thessaloniki (Greece); Chourmouzi, D.; Boulogianni, G. [Asklipios-Aristotelio Diagnostic Centre, Thessaloniki (Greece); Pitsavas, G. [Paediatric Clinic, AHEPA University Hospital, Thessaloniki (Greece); Charitandi, A. [Dept. of Radiology, AHEPA University Hospital, Thessaloniki (Greece)

    2001-10-01

    Anorexia nervosa (AN), usually seen in young girls, is characterised by severe emaciation induced by self-imposed starvation. Enlargement of the ventricular system and sulci has been reported, as has high signal on T2-weighted images. We present a case with atrophic changes and high signal on T2-weighted images, which resolved completely following weight gain. (orig.)

  2. Perturbation and Nonlinear Dynamic Analysis of Acoustic Phonatory Signal in Parkinsonian Patients Receiving Deep Brain Stimulation

    Science.gov (United States)

    Lee, Victoria S.; Zhou, Xiao Ping; Rahn, Douglas A., III; Wang, Emily Q.; Jiang, Jack J.

    2008-01-01

    Nineteen PD patients who received deep brain stimulation (DBS), 10 non-surgical (control) PD patients, and 11 non-pathologic age- and gender-matched subjects performed sustained vowel phonations. The following acoustic measures were obtained on the sustained vowel phonations: correlation dimension (D[subscript 2]), percent jitter, percent shimmer,…

  3. Signal changes in gradient echo images of human brain induced by hypo- and hyperoxia

    DEFF Research Database (Denmark)

    Rostrup, Egill; Larsson, H B; Toft, P B; Garde, K; Henriksen, O

    1995-01-01

    The effect of hypoxia (inspired oxygen fraction, FiO2 of 10% and 16%) and hyperoxia (FiO2) of 100%) on gradient echo images of the brain using long echo times was investigated in six healthy volunteers (age 24-28 years). Different flip angles were used with an FiO2 of 10% to assess the importance...

  4. Complex patterns of signalling to convey different social goals of sex in bonobos, Pan paniscus

    Science.gov (United States)

    Genty, Emilie; Neumann, Christof; Zuberbühler, Klaus

    2015-01-01

    Sexual behaviour in bonobos (Pan paniscus) functions beyond mere reproduction to mediate social interactions and relationships. In this study, we assessed the signalling behaviour in relation to four social goals of sex in this species: appeasement after conflict, tension reduction, social bonding and reproduction. Overall, sexual behaviour was strongly decoupled from its ancestral reproductive function with habitual use in the social domain, which was accompanied by a corresponding complexity in communication behaviour. We found that signalling behaviour varied systematically depending on the initiator’s goals and gender. Although all gestures and vocalisations were part of the species-typical communication repertoire, they were often combined and produced flexibly. Generally, gestures and multi-modal combinations were more flexibly used to communicate a goal than vocalisations. There was no clear relation between signalling behaviour and success of sexual initiations, suggesting that communication was primarily used to indicate the signaller’s intention, and not to influence a recipient’s willingness to interact sexually. We discuss these findings in light of the larger question of what may have caused, in humans, the evolutionary transition from primate-like communication to language. PMID:26538281

  5. Pharmacology of bile acid receptors: Evolution of bile acids from simple detergents to complex signaling molecules.

    Science.gov (United States)

    Copple, Bryan L; Li, Tiangang

    2016-02-01

    For many years, bile acids were thought to only function as detergents which solubilize fats and facilitate the uptake of fat-soluble vitamins in the intestine. Many early observations; however, demonstrated that bile acids regulate more complex processes, such as bile acids synthesis and immune cell function through activation of signal transduction pathways. These studies were the first to suggest that receptors may exist for bile acids. Ultimately, seminal studies by many investigators led to the discovery of several bile acid-activated receptors including the farnesoid X receptor, the vitamin D receptor, the pregnane X receptor, TGR5, α5 β1 integrin, and sphingosine-1-phosphate receptor 2. Several of these receptors are expressed outside of the gastrointestinal system, indicating that bile acids may have diverse functions throughout the body. Characterization of the functions of these receptors over the last two decades has identified many important roles for these receptors in regulation of bile acid synthesis, transport, and detoxification; regulation of glucose utilization; regulation of fatty acid synthesis and oxidation; regulation of immune cell function; regulation of energy expenditure; and regulation of neural processes such as gastric motility. Through these many functions, bile acids regulate many aspects of digestion ranging from uptake of essential vitamins to proper utilization of nutrients. Accordingly, within a short time period, bile acids moved beyond simple detergents and into the realm of complex signaling molecules. Because of the important processes that bile acids regulate through activation of receptors, drugs that target these receptors are under development for the treatment of several diseases, including cholestatic liver disease and metabolic syndrome. In this review, we will describe the various bile acid receptors, the signal transduction pathways activated by these receptors, and briefly discuss the physiological processes that

  6. Astaxanthin Alleviates Early Brain Injury Following Subarachnoid Hemorrhage in Rats: Possible Involvement of Akt/Bad Signaling

    Directory of Open Access Journals (Sweden)

    Xiang-Sheng Zhang

    2014-07-01

    Full Text Available Apoptosis has been proven to play a crucial role in early brain injury pathogenesis and to represent a target for the treatment of subarachnoid hemorrhage (SAH. Previously, we demonstrated that astaxanthin (ATX administration markedly reduced neuronal apoptosis in the early period after SAH. However, the underlying molecular mechanisms remain obscure. In the present study, we tried to investigate whether ATX administration is associated with the phosphatidylinositol 3-kinase-Akt (PI3K/Akt pathway, which can play an important role in the signaling of apoptosis. Our results showed that post-SAH treatment with ATX could cause a significant increase of phosphorylated Akt and Bad levels, along with a significant decrease of cleaved caspase-3 levels in the cortex after SAH. In addition to the reduced neuronal apoptosis, treatment with ATX could also significantly reduce secondary brain injury characterized by neurological dysfunction, cerebral edema and blood-brain barrier disruption. In contrast, the PI3K/Akt inhibitor, LY294002, could partially reverse the neuroprotection of ATX in the early period after SAH by downregulating ATX-induced activation of Akt/Bad and upregulating cleaved caspase-3 levels. These results provided the evidence that ATX could attenuate apoptosis in a rat SAH model, potentially, in part, through modulating the Akt/Bad pathway.

  7. Mechanisms of extracellular signal-regulated kinase/cAMP response element-binding protein/brain-derived neurotrophic factor signaltransduction pathway in depressive disorder

    Institute of Scientific and Technical Information of China (English)

    Hongyan Wang; Yingquan Zhang; Mingqi Qiao

    2013-01-01

    The extracellular signal-regulated kinase/cAMP response element-binding protein/brain-derived neurotrophic factor signal transduction pathway plays an important role in the mechanism of action of antidepressant drugs and has dominated recent studies on the pathogenesis of depression. In the present review we summarize the known roles of extracellular signal-regulated kinase, cAMP response element-binding protein and brain-derived neurotrophic factor in the pathogenesis of depression and in the mechanism of action of antidepressant medicines. The extracellular signal-regulated kinase/cAMP response element-binding protein/brain-derived neurotrophic factor pathway has potential to be used as a biological index to help diagnose depression, and as such it is considered as an important new target in the treatment of depression.

  8. Attention modulations of posterior alpha as a control signal for two-dimensional brain-computer interfaces.

    Science.gov (United States)

    van Gerven, Marcel; Jensen, Ole

    2009-04-30

    Research on brain-computer interfaces (BCIs) is gaining strong interest. This is motivated by BCIs being applicable for helping disabled, for gaming, and as a tool in cognitive neuroscience. Often, motor imagery is used to produce (binary) control signals. However, finding other types of control signals that allow the discrimination of multiple classes would help to increase the applicability of BCIs. We have investigated if modulation of posterior alpha activity by means of covert spatial attention in two dimensions can be reliably classified in single trials. Magnetoencephalography (MEG) data were collected for 15 subjects who were engaged in a task where they covertly had to visually attend left, right, up or down during a period of 2500 ms. We then classified the trials using support vector machines. The four orientations of covert attention could be reliably classified up to a maximum of 69% correctly classified trials (25% chance level) without the need for lengthy and burdensome subject training. Low classification performance in some subjects was explained by a low alpha signal. These findings support the case that modulation of alpha activity by means of covert spatial attention is promising as a control signal for a two-dimensional BCI. PMID:19428515

  9. Final Report on LDRD project 130784 : functional brain imaging by tunable multi-spectral Event-Related Optical Signal (EROS).

    Energy Technology Data Exchange (ETDEWEB)

    Speed, Ann Elizabeth; Spahn, Olga Blum; Hsu, Alan Yuan-Chun

    2009-09-01

    Functional brain imaging is of great interest for understanding correlations between specific cognitive processes and underlying neural activity. This understanding can provide the foundation for developing enhanced human-machine interfaces, decision aides, and enhanced cognition at the physiological level. The functional near infrared spectroscopy (fNIRS) based event-related optical signal (EROS) technique can provide direct, high-fidelity measures of temporal and spatial characteristics of neural networks underlying cognitive behavior. However, current EROS systems are hampered by poor signal-to-noise-ratio (SNR) and depth of measure, limiting areas of the brain and associated cognitive processes that can be investigated. We propose to investigate a flexible, tunable, multi-spectral fNIRS EROS system which will provide up to 10x greater SNR as well as improved spatial and temporal resolution through significant improvements in electronics, optoelectronics and optics, as well as contribute to the physiological foundation of higher-order cognitive processes and provide the technical foundation for miniaturized portable neuroimaging systems.

  10. JNK Signaling: Regulation and Functions Based on Complex Protein-Protein Partnerships.

    Science.gov (United States)

    Zeke, András; Misheva, Mariya; Reményi, Attila; Bogoyevitch, Marie A

    2016-09-01

    The c-Jun N-terminal kinases (JNKs), as members of the mitogen-activated protein kinase (MAPK) family, mediate eukaryotic cell responses to a wide range of abiotic and biotic stress insults. JNKs also regulate important physiological processes, including neuronal functions, immunological actions, and embryonic development, via their impact on gene expression, cytoskeletal protein dynamics, and cell death/survival pathways. Although the JNK pathway has been under study for >20 years, its complexity is still perplexing, with multiple protein partners of JNKs underlying the diversity of actions. Here we review the current knowledge of JNK structure and isoforms as well as the partnerships of JNKs with a range of intracellular proteins. Many of these proteins are direct substrates of the JNKs. We analyzed almost 100 of these target proteins in detail within a framework of their classification based on their regulation by JNKs. Examples of these JNK substrates include a diverse assortment of nuclear transcription factors (Jun, ATF2, Myc, Elk1), cytoplasmic proteins involved in cytoskeleton regulation (DCX, Tau, WDR62) or vesicular transport (JIP1, JIP3), cell membrane receptors (BMPR2), and mitochondrial proteins (Mcl1, Bim). In addition, because upstream signaling components impact JNK activity, we critically assessed the involvement of signaling scaffolds and the roles of feedback mechanisms in the JNK pathway. Despite a clarification of many regulatory events in JNK-dependent signaling during the past decade, many other structural and mechanistic insights are just beginning to be revealed. These advances open new opportunities to understand the role of JNK signaling in diverse physiological and pathophysiological states. PMID:27466283

  11. Brain Basics

    Medline Plus

    Full Text Available ... Brain Basics will introduce you to some of this science, such as: How the brain develops How ... cell, and responds to signals from the environment; this all helps the cell maintain its balance with ...

  12. Brain mapping

    OpenAIRE

    Blaž Koritnik

    2004-01-01

    Cartography of the brain ("brain mapping") aims to represent the complexities of the working brain in an understandable and usable way. There are four crucial steps in brain mapping: (1) acquiring data about brain structure and function, (2) transformation of data into a common reference, (3) visualization and interpretation of results, and (4) databasing and archiving. Electrophysiological and functional imaging methods provide information about function of the human brain. A prere...

  13. Music Composition from the Brain Signal: Representing the Mental State by Music

    Directory of Open Access Journals (Sweden)

    Dan Wu

    2010-01-01

    Full Text Available This paper proposes a method to translate human EEG into music, so as to represent mental state by music. The arousal levels of the brain mental state and music emotion are implicitly used as the bridge between the mind world and the music. The arousal level of the brain is based on the EEG features extracted mainly by wavelet analysis, and the music arousal level is related to the musical parameters such as pitch, tempo, rhythm, and tonality. While composing, some music principles (harmonics and structure were taken into consideration. With EEGs during various sleep stages as an example, the music generated from them had different patterns of pitch, rhythm, and tonality. 35 volunteers listened to the music pieces, and significant difference in music arousal levels was found. It implied that different mental states may be identified by the corresponding music, and so the music from EEG may be a potential tool for EEG monitoring, biofeedback therapy, and so forth.

  14. Cortical complexity as a measure of age-related brain atrophy.

    Science.gov (United States)

    Madan, Christopher R; Kensinger, Elizabeth A

    2016-07-01

    The structure of the human brain changes in a variety of ways as we age. While a sizeable literature has examined age-related differences in cortical thickness, and to a lesser degree, gyrification, here we examined differences in cortical complexity, as indexed by fractal dimensionality in a sample of over 400 individuals across the adult lifespan. While prior studies have shown differences in fractal dimensionality between patient populations and age-matched, healthy controls, it is unclear how well this measure would relate to age-related cortical atrophy. Initially computing a single measure for the entire cortical ribbon, i.e., unparcellated gray matter, we found fractal dimensionality to be more sensitive to age-related differences than either cortical thickness or gyrification index. We additionally observed regional differences in age-related atrophy between the three measures, suggesting that they may index distinct differences in cortical structure. We also provide a freely available MATLAB toolbox for calculating fractal dimensionality. PMID:27103141

  15. Candesartan and glycyrrhizin ameliorate ischemic brain damage through downregulation of the TLR signaling cascade.

    Science.gov (United States)

    Barakat, Waleed; Safwet, Nancy; El-Maraghy, Nabila N; Zakaria, Mohamed N M

    2014-02-01

    Stroke is the second leading cause of death in industrialized countries and the most frequent cause of permanent disability in adults worldwide. The final outcome of stroke is determined not only by the volume of the ischemic core, but also by the extent of secondary brain damage inflicted to penumbral tissues by brain swelling, impaired microcirculation, and inflammation. The only drug approved for the treatment ischemic stroke is recombinant tissue plasminogen activator (rt-PA). The current study was designed to investigate the protective effects of candesartan (0.15 mg/kg, orally) and glycyrrhizin (30 mg/kg, orally) experimentally-induced ischemic brain damage in C57BL/6 mice (middle cerebral artery occlusion, MCAO) in comparison to the effects of a standard neuroprotective drug (cerebrolysin, 7.5 mg/kg, IP). All drugs were administered 30 min before and 24h after MCAO. Both candesartan and glycyrrhizin ameliorated the deleterious effects of MCAO as indicated by the improvement in the performance of the animals in behaviour tests, reduction in brain infarction, neuronal degeneration, and leukocyte infiltration. In addition, MCAO induced a significant upregulation in the different elements of the TLR pathway including TLR-2 and TLR-4, Myd88, TRIF and IRF-3 and the downstream effectors TNF-α, IL-1β, IL-6 and NF-kB. All these changes were significantly ameliorated by treatment with candesartan and glycyrrhizin. The results of the current study represent a new indication for both candesartan and glycyrrhizin in the management of ischemic stroke with effects comparable to those of the standard neuroprotective drug cerebrolysin. PMID:24378346

  16. BrainSignals Revisited: Simplifying a Computational Model of Cerebral Physiology

    OpenAIRE

    Caldwell, M; Hapuarachchi, T.; Highton, D.; Elwell, C.; Smith, M.; Tachtsidis, I.

    2015-01-01

    Multimodal monitoring of brain state is important both for the investigation of healthy cerebral physiology and to inform clinical decision making in conditions of injury and disease. Near-infrared spectroscopy is an instrument modality that allows non-invasive measurement of several physiological variables of clinical interest, notably haemoglobin oxygenation and the redox state of the metabolic enzyme cytochrome c oxidase. Interpreting such measurements requires the integration of multiple ...

  17. Classification of EEG Signals in a Brain-Computer Interface System

    OpenAIRE

    Larsen, Erik Andreas

    2011-01-01

    Electroencephalography (EEG) equipment are becoming more available on thepublic market, which enables more diverse research in a currently narrow field.The Brain-Computer Interface (BCI) community recognize the need for systemsthat makes BCI more user-friendly, real-time, manageable and suited for peoplethat are not forced to use them, like clinical patients, and those who are disabled.Thus, this project is an effort to seek such improvements, having a newly availablemarket product to experim...

  18. Storm in a coffee cup: caffeine modifies brain activation to social signals of threat

    OpenAIRE

    Smith, Jessica E.; Lawrence, Andrew D; Diukova, Ana; Wise, Richard G; Rogers, Peter J.

    2011-01-01

    Caffeine, an adenosine A1 and A2A receptor antagonist, is the most popular psychostimulant drug in the world, but it is also anxiogenic. The neural correlates of caffeine-induced anxiety are currently unknown. This study investigated the effects of caffeine on brain regions implicated in social threat processing and anxiety. Participants were 14 healthy male non/infrequent caffeine consumers. In a double-blind placebo-controlled crossover design, they underwent blood oxygenation level-depende...

  19. Dual Roles for Perivascular Macrophages in Immune-to-Brain Signaling

    OpenAIRE

    Serrats, Jordi; Schiltz, Jennifer C.; García-Bueno, Borja; Van Rooijen, Nico; Reyes, Teresa M.; Sawchenko, Paul E.

    2010-01-01

    Cytokines produced during infection/inflammation activate adaptive CNS responses, including acute stress responses mediated by the hypothalamo-pituitary-adrenal (HPA) axis. The mechanisms by which cytokines engage HPA control circuitry remain unclear, though stimulated release of prostanoids from neighboring vascular cells has been implicated in this regard. How specific vascular cell types, endothelial cells (ECs) vs. perivascular cells (PVCs; a subset of brain-resident macrophages), partici...

  20. Power law scaling in synchronization of brain signals depends on cognitive load

    OpenAIRE

    Jose Luis Perez Velazquez

    2014-01-01

    As it has several features that optimize information processing, it has been proposed that criticality governs the dynamics of nervous system activity. Indications of such dynamics have been reported for a variety of in vitro and in vivo recordings, ranging from in vitro slice electrophysiology to human functional magnetic resonance imaging. However, there still remains considerable debate as to whether the brain actually operates close to criticality or in another governing state such as sto...

  1. Power law scaling in synchronization of brain signals depends on cognitive load

    Science.gov (United States)

    Tinker, Jesse; Velazquez, Jose Luis Perez

    2014-01-01

    As it has several features that optimize information processing, it has been proposed that criticality governs the dynamics of nervous system activity. Indications of such dynamics have been reported for a variety of in vitro and in vivo recordings, ranging from in vitro slice electrophysiology to human functional magnetic resonance imaging. However, there still remains considerable debate as to whether the brain actually operates close to criticality or in another governing state such as stochastic or oscillatory dynamics. A tool used to investigate the criticality of nervous system data is the inspection of power-law distributions. Although the findings are controversial, such power-law scaling has been found in different types of recordings. Here, we studied whether there is a power law scaling in the distribution of the phase synchronization derived from magnetoencephalographic recordings during executive function tasks performed by children with and without autism. Characterizing the brain dynamics that is different between autistic and non-autistic individuals is important in order to find differences that could either aid diagnosis or provide insights as to possible therapeutic interventions in autism. We report in this study that power law scaling in the distributions of a phase synchrony index is not very common and its frequency of occurrence is similar in the control and the autism group. In addition, power law scaling tends to diminish with increased cognitive load (difficulty or engagement in the task). There were indications of changes in the probability distribution functions for the phase synchrony that were associated with a transition from power law scaling to lack of power law (or vice versa), which suggests the presence of phenomenological bifurcations in brain dynamics associated with cognitive load. Hence, brain dynamics may fluctuate between criticality and other regimes depending upon context and behaviors. PMID:24822039

  2. Power law scaling in synchronization of brain signals depends on cognitive load

    Directory of Open Access Journals (Sweden)

    Jose Luis ePerez Velazquez

    2014-05-01

    Full Text Available As it has several features that optimize information processing, it has been proposed that criticality governs the dynamics of nervous system activity. Indications of such dynamics have been reported for a variety of in vitro and in vivo recordings, ranging from in vitro slice electrophysiology to human functional magnetic resonance imaging. However, there still remains considerable debate as to whether the brain actually operates close to criticality or in another governing state such as stochastic or oscillatory dynamics. A tool used to investigate the criticality of nervous system data is the inspection of power-law distributions. Although the findings are controversial, such power-law scaling has been found in different types of recordings. Here, we studied whether there is a power law scaling in the distribution of the phase synchronization derived from magnetoencephalographic recordings during executive function tasks performed by children with and without autism. Characterizing the brain dynamics that is different between autistic and non-autistic individuals is important in order to find differences that could either aid diagnosis or provide insights as to possible therapeutic interventions in autism. We report in this study that power law scaling in the distributions of a phase synchrony index is not very common and its frequency of occurrence is similar in the control and the autism group. In addition, power law scaling tends to diminish with increased cognitive load (difficulty or engagement in the task. There were indications of changes in the probability distribution functions for the phase synchrony that were associated with a transition from power law scaling to lack of power law (or vice versa, which suggests the presence of phenomenological bifurcations in brain dynamics associated with cognitive load. Hence, brain dynamics may fluctuate between criticality and other regimes depending upon context and behaviours.

  3. Compound heterozygosity for mutations in PAX6 in a patient with complex brain anomaly, neonatal diabetes mellitus, and microophthalmia.

    Science.gov (United States)

    Solomon, Benjamin D; Pineda-Alvarez, Daniel E; Balog, Joan Z; Hadley, Donald; Gropman, Andrea L; Nandagopal, Radha; Han, Joan C; Hahn, Jin S; Blain, Delphine; Brooks, Brian; Muenke, Maximilian

    2009-11-01

    We report on a patient with trisomy 21, microophthalmia, neonatal diabetes mellitus, hypopituitarism, and a complex structural brain anomaly who was a member of a large bilineal family with eye anomalies. The patient inherited a different mutation in PAX6 from each parent and is the only known living and second reported patient with compound heterozygosity for mutations in PAX6. PAX6 is a transcription factor involved in eye and brain development and has roles in pancreatic and pituitary development. Clinical evaluation of the propositus and his parents demonstrated the effects of mutations of differing severity in multiple individuals. PMID:19876904

  4. Compound Heterozygosity for Mutations in PAX6 in Patient with Complex Brain Anomaly, Neonatal Diabetes Mellitus, and Microophthalmia

    Science.gov (United States)

    Solomon, Benjamin D.; Pineda-Alvarez, Daniel E.; Balog, Joan Z.; Hadley, Donald; Gropman, Andrea L.; Nandagopal, Radha; Han, Joan C.; Hahn, Jin S.; Blain, Delphine; Brooks, Brian; Muenke, Maximilian

    2009-01-01

    We report on a patient with trisomy 21, microophthalmia, neonatal diabetes mellitus, hypopituitarism, and a complex structural brain anomaly who was a member of a large bilineal family with eye anomalies. The patient inherited a different mutation in PAX6 from each parent and is the only known living and second reported patient with compound heterozygosity for mutations in PAX6. PAX6 is a transcription factor involved in eye and brain development, and has roles in pancreatic and pituitary development. Clinical evaluation of the propositus and his parents demonstrated the effects of mutations of differing severity in multiple individuals. PMID:19876904

  5. Miniaturized Swimming Soft Robot with Complex Movement Actuated and Controlled by Remote Light Signals

    Science.gov (United States)

    Huang, Chaolei; Lv, Jiu-An; Tian, Xiaojun; Wang, Yuechao; Yu, Yanlei; Liu, Jie

    2015-12-01

    Powering and communication with micro robots to enable complex functions is a long-standing challenge as the size of robots continues to shrink. Physical connection of wires or components needed for wireless communication are complex and limited by the size of electronic and energy storage devices, making miniaturization of robots difficult. To explore an alternative solution, we designed and fabricated a micro soft swimming robot with both powering and controlling functions provided by remote light, which does not carry any electronic devices and batteries. In this approach, a polymer film containing azobenzene chromophore which is sensitive to ultra-violet (UV) light works as “motor”, and the UV light and visible light work as “power and signal lines”. Periodically flashing UV light and white light drives the robot flagellum periodically to swing to eventually push forward the robot in the glass tube filled with liquid. The gripper on robot head can be opened or closed by lights to grab and carry the load. This kind of remotely light-driven approach realizes complex driving and controlling of micro robotic structures, making it possible to design and fabricate even smaller robots. It will have great potential among applications in the micro machine and robot fields.

  6. Another kind of 'BOLD Response': answering multiple-choice questions via online decoded single-trial brain signals.

    Science.gov (United States)

    Sorger, Bettina; Dahmen, Brigitte; Reithler, Joel; Gosseries, Olivia; Maudoux, Audrey; Laureys, Steven; Goebel, Rainer

    2009-01-01

    The term 'locked-in'syndrome (LIS) describes a medical condition in which persons concerned are severely paralyzed and at the same time fully conscious and awake. The resulting anarthria makes it impossible for these patients to naturally communicate, which results in diagnostic as well as serious practical and ethical problems. Therefore, developing alternative, muscle-independent communication means is of prime importance. Such communication means can be realized via brain-computer interfaces (BCIs) circumventing the muscular system by using brain signals associated with preserved cognitive, sensory, and emotional brain functions. Primarily, BCIs based on electrophysiological measures have been developed and applied with remarkable success. Recently, also blood flow-based neuroimaging methods, such as functional magnetic resonance imaging (fMRI) and functional near-infrared spectroscopy (fNIRS), have been explored in this context. After reviewing recent literature on the development of especially hemodynamically based BCIs, we introduce a highly reliable and easy-to-apply communication procedure that enables untrained participants to motor-independently and relatively effortlessly answer multiple-choice questions based on intentionally generated single-trial fMRI signals that can be decoded online. Our technique takes advantage of the participants' capability to voluntarily influence certain spatio-temporal aspects of the blood oxygenation level-dependent (BOLD) signal: source location (by using different mental tasks), signal onset and offset. We show that healthy participants are capable of hemodynamically encoding at least four distinct information units on a single-trial level without extensive pretraining and with little effort. Moreover, real-time data analysis based on simple multi-filter correlations allows for automated answer decoding with a high accuracy (94.9%) demonstrating the robustness of the presented method. Following our 'proof of concept', the

  7. Effects of Habitat and Social Complexity on Brain Size, Brain Asymmetry and Dentate Gyrus Morphology in Two Octodontid Rodents.

    Science.gov (United States)

    Sobrero, Raúl; Fernández-Aburto, Pedro; Ly-Prieto, Álvaro; Delgado, Scarlett E; Mpodozis, Jorge; Ebensperger, Luis A

    2016-01-01

    Navigational and social challenges due to habitat conditions and sociality are known to influence dentate gyrus (DG) morphology, yet the relative importance of these factors remains unclear. Thus, we studied three natural populations of O. lunatus (Los Molles) and Octodon degus (El Salitre and Rinconada), two caviomorph species that differ in the extent of sociality and with contrasting vegetation cover of habitat used. The brains and DG of male and female breeding degus with simultaneous information on their physical and social environments were examined. The extent of sociality was quantified from total group size and range area overlap. O. degus at El Salitre was more social than at Rinconada and than O. lunatus from Los Molles. The use of transects to quantify cover of vegetation (and other physical objects in the habitat) and measures of the spatial behavior of animals indicated animal navigation based on unique cues or global landmarks is more cognitively challenging to O. lunatus. During lactation, female O. lunatus had larger brains than males. Relative DG volume was similar across sexes and populations. The right hemisphere of male and female O. lunatus had more cells than the left hemisphere, with DG directional asymmetry not found in O. degus. Degu population differences in brain size and DG cell number seemed more responsive to differences in habitat than to differences in sociality. Yet, large-sized O. degus (but not O. lunatus) that ranged over larger areas and were members of larger social groups had more DG cells per hemisphere. Thus, within-population variation in DG cell number by hemisphere was consistent with a joint influence of habitat and sociality in O. degus at El Salitre. PMID:27045373

  8. Synthesis characterization and biological evaluation of a novel mixed ligand 99mTc complex as potential brain imaging agent

    International Nuclear Information System (INIS)

    One approach in the design of neutral oxotechnetium complexes is based on the simultaneous substitution of a tridentate dianionic ligand and a monodentate monoanionic coligand on a [Tc(V)O]+3 precursor. Following this ''mixed ligand'' concept, a novel 99mTc complex with N,N-bis(2-mercaptoethyl)-N'N'-diethylethylenediamine as ligand and 1-octanethiol as coligand is prepared and evaluated as potential brain radiopharmaceutical. Preparation of the complex at tracer level was accomplished by using 99mTc-glucoheptonate as precursor. The substitution was optimized and a coligand/ligand ratio of 5 was selected. Under this conditions the labeling yield was over 80% and a major product (with radiochemical purity > 80%) was isolated by HPLC methods and used for biological evaluation. Chemical characterization at carrier level was developed using the corresponding rhenium complex as structural model. The Re complex was also prepared by substitution method and isolated as a crystalline product. The crystals were characterized by UV-vis and IR spectra and elemental analysis. Results were consistent with the expected ReOLC structure. X ray crystallographic study demonstrated that the complex adopts a distorted trigonal bipyramidal geometry. The basal plane is defined by the SS atoms of the ligand and the oxo group, while the N of the ligand and the S of the colligand occupy the two apical positions. All sulphur atoms underwent ionization leading to the formation of a neutral compound. 99Tc complex was also prepared. Although it was not isolated due to the small amount of reagents employed, the HPLC profile was identical to the one observed for the rhenium complex suggesting the same chemical structure. Biodistribution in mice demonstrated early brain uptake, fast blood clearance, excretion through hepatobiliary system and a brain/blood ratio that increased significantly with time. (author)

  9. The Hrs/Stam complex acts as a positive and negative regulator of RTK signaling during Drosophila development.

    Directory of Open Access Journals (Sweden)

    Hélène Chanut-Delalande

    Full Text Available BACKGROUND: Endocytosis is a key regulatory step of diverse signalling pathways, including receptor tyrosine kinase (RTK signalling. Hrs and Stam constitute the ESCRT-0 complex that controls the initial selection of ubiquitinated proteins, which will subsequently be degraded in lysosomes. It has been well established ex vivo and during Drosophila embryogenesis that Hrs promotes EGFR down regulation. We have recently isolated the first mutations of stam in flies and shown that Stam is required for air sac morphogenesis, a larval respiratory structure whose formation critically depends on finely tuned levels of FGFR activity. This suggest that Stam, putatively within the ESCRT-0 complex, modulates FGF signalling, a possibility that has not been examined in Drosophila yet. PRINCIPAL FINDINGS: Here, we assessed the role of the Hrs/Stam complex in the regulation of signalling activity during Drosophila development. We show that stam and hrs are required for efficient FGFR signalling in the tracheal system, both during cell migration in the air sac primordium and during the formation of fine cytoplasmic extensions in terminal cells. We find that stam and hrs mutant cells display altered FGFR/Btl localisation, likely contributing to impaired signalling levels. Electron microscopy analyses indicate that endosome maturation is impaired at distinct steps by hrs and stam mutations. These somewhat unexpected results prompted us to further explore the function of stam and hrs in EGFR signalling. We show that while stam and hrs together downregulate EGFR signalling in the embryo, they are required for full activation of EGFR signalling during wing development. CONCLUSIONS/SIGNIFICANCE: Our study shows that the ESCRT-0 complex differentially regulates RTK signalling, either positively or negatively depending on tissues and developmental stages, further highlighting the importance of endocytosis in modulating signalling pathways during development.

  10. The Study of Properties of n-D Analytic Signals and Their Spectra in Complex and Hypercomplex Domains

    Directory of Open Access Journals (Sweden)

    K. M. Snopek

    2012-04-01

    Full Text Available In the paper, two various representations of a n-dimensional (n-D real signal u(x1,x2,…,xn are investigated. The first one is the n-D complex analytic signal with a single-orthant spectrum defined by Hahn in 1992 as the extension of the 1-D Gabor’s analytic signal. It is compared with two hypercomplex approaches: the known n-D Clifford analytic signal and the Cayley-Dickson analytic signal defined by the Author in 2009. The signal-domain and frequency-domain definitions of these signals are presented and compared in 2-D and 3-D. Some new relations between the spectra in 2-D and 3-D hypercomplex domains are presented. The paper is illustrated with the example of a 2-D separable Cauchy pulse.

  11. Pre-ischemic treadmill training alleviates brain damage via GLT-1-mediated signal pathway after ischemic stroke in rats.

    Science.gov (United States)

    Wang, X; Zhang, M; Yang, S-D; Li, W-B; Ren, S-Q; Zhang, J; Zhang, F

    2014-08-22

    Physical exercise could play a neuroprotective role in both human and animals. However, the involved signal pathways underlying the neuroprotective effect are still not well established. This study was to investigate the possible signal pathways involved in the neuroprotection of pre-ischemic treadmill training after ischemic stroke. Seventy-two SD rats were randomly assigned into three groups (n=24/group): sham surgery group, middle cerebral artery occlusion (MCAO) group and MCAO with exercise group. Following three weeks of treadmill training exercise, ischemic stroke was induced by occluding the middle cerebral artery (MCA) in rat for 2 h, followed by reperfusion. Twenty-four hours after MCAO/reperfusion, 12 rats in each group were evaluated for neurological deficit scores and then sacrificed to measure the infarct volume (n=6) and cerebral edema (n=6). Six rats in each group were sacrificed to measure the expression level of glutamate transporter-1 (GLT-1), protein kinase C-α (PKC-α), Akt, and phosphatidylinositol 3 kinase (PI3K) (n=6). Two hundred and eighty minutes (4.67 h) after occlusion, six rats in each group were decapitated to detect the mRNA expression level of metabotropic glutamate receptor 5 (mGluR5) and N-methyl-D-aspartate receptor subunit type 2B (NR2B) (n=6).The results demonstrated that pre-ischemic treadmill training exercise reduced brain infarct volume, cerebral edema and neurological deficits, also decreased the over expression of PKC-α and increased the expression level of GLT-1, Akt and PI3K after ischemic stroke (pexercise (pexercise preconditioning ameliorated brain damage after ischemic stroke, which might be involved in two signal pathways: PKC-α-GLT-1-Glutamate and PI3K/Akt-GLT-1-Glutamate. PMID:24907601

  12. Mitochondrial complex I dysfunction induced by cocaine and cocaine plus morphine in brain and liver mitochondria

    OpenAIRE

    cunha-oliveira, teresa; Silva, Lisbeth; Silva, Ana Maria; Moreno, António J.; Oliveira, Catarina R.; Santos, Maria S.

    2013-01-01

    Mitochondrial function and energy metabolism are affected in brains of human cocaine abusers. Cocaine is known to induce mitochondrial dysfunction in cardiac and hepatic tissues, but its effects on brain bioenergetics are less documented. Furthermore, the combination of cocaine and opioids (speedball) was also shown to induce mitochondrial dysfunction. In this work, we compared the effects of cocaine and/or morphine on the bioenergetics of isolated brain and liver mitochondria, to understand ...

  13. Beyond the brain-Peripheral kisspeptin signaling is essential for promoting endometrial gland development and function.

    Science.gov (United States)

    León, Silvia; Fernadois, Daniela; Sull, Alexandra; Sull, Judith; Calder, Michele; Hayashi, Kanako; Bhattacharya, Moshmi; Power, Stephen; Vilos, George A; Vilos, Angelos G; Tena-Sempere, Manuel; Babwah, Andy V

    2016-01-01

    Uterine growth and endometrial gland formation (adenogenesis) and function, are essential for fertility and are controlled by estrogens and other regulators, whose nature and physiological relevance are yet to be elucidated. Kisspeptin, which signals via Kiss1r, is essential for fertility, primarily through its central control of the hypothalamic-pituitary-ovarian axis, but also likely through peripheral actions. Using genetically modified mice, we addressed the contributions of central and peripheral kisspeptin signaling in regulating uterine growth and adenogenesis. Global ablation of Kiss1 or Kiss1r dramatically suppressed uterine growth and almost fully prevented adenogenesis. However, while uterine growth was fully rescued by E2 treatment of Kiss1(-/-) mice and by genetic restoration of kisspeptin signaling in GnRH neurons in Kiss1r(-/-) mice, functional adenogenesis was only marginally restored. Thus, while uterine growth is largely dependent on ovarian E2-output via central kisspeptin signaling, peripheral kisspeptin signaling is indispensable for endometrial adenogenesis and function, essential aspects of reproductive competence. PMID:27364226

  14. fMRI brain mapping during motion capture and FES induced motor tasks: signal to noise ratio assessment.

    Science.gov (United States)

    Gandolla, Marta; Ferrante, Simona; Casellato, Claudia; Ferrigno, Giancarlo; Molteni, Franco; Martegani, Alberto; Frattini, Tiziano; Pedrocchi, Alessandra

    2011-10-01

    Functional Electrical Stimulation (FES) is a well known clinical rehabilitation procedure, however the neural mechanisms that underlie this treatment at Central Nervous System (CNS) level are still not completely understood. Functional magnetic resonance imaging (fMRI) is a suitable tool to investigate effects of rehabilitative treatments on brain plasticity. Moreover, monitoring the effective executed movement is needed to correctly interpret activation maps, most of all in neurological patients where required motor tasks could be only partially accomplished. The proposed experimental set-up includes a 1.5 T fMRI scanner, a motion capture system to acquire kinematic data, and an electro-stimulation device. The introduction of metallic devices and of stimulation current in the MRI room could affect fMRI acquisitions so as to prevent a reliable activation maps analysis. What we are interested in is that the Blood Oxygenation Level Dependent (BOLD) signal, marker of neural activity, could be detected within a given experimental condition and set-up. In this paper we assess temporal Signal to Noise Ratio (SNR) as image quality index. BOLD signal change is about 1-2% as revealed by a 1.5 T scanner. This work demonstrates that, with this innovative set-up, in the main cortical sensorimotor regions 1% BOLD signal change can be detected at least in the 93% of the sub-volumes, and almost 100% of the sub-volumes are suitable for 2% signal change detection. The integrated experimental set-up will therefore allows to detect FES induced movements fMRI maps simultaneously with kinematic acquisitions so as to investigate FES-based rehabilitation treatments contribution at CNS level. PMID:21550290

  15. A low complexity, low spur digital IF conversion circuit for high-fidelity GNSS signal playback

    Science.gov (United States)

    Su, Fei; Ying, Rendong

    2016-01-01

    A low complexity high efficiency and low spur digital intermediate frequency (IF) conversion circuit is discussed in the paper. This circuit is key element in high-fidelity GNSS signal playback instrument. We analyze the spur performance of a finite state machine (FSM) based numerically controlled oscillators (NCO), by optimization of the control algorithm, a FSM based NCO with 3 quantization stage can achieves 65dB SFDR in the range of the seventh harmonic. Compare with traditional lookup table based NCO design with the same Spurious Free Dynamic Range (SFDR) performance, the logic resource require to implemented the NCO is reduced to 1/3. The proposed design method can be extended to the IF conversion system with good SFDR in the range of higher harmonic components by increasing the quantization stage.

  16. Ant Queen Egg-Marking Signals: Matching Deceptive Laboratory Simplicity with Natural Complexity

    DEFF Research Database (Denmark)

    van Zweden, Jelle Stijn; Heinze, Jürgen; Boomsma, Jacobus Jan;

    2009-01-01

    Background Experiments under controlled laboratory conditions can produce decisive evidence for testing biological hypotheses, provided they are representative of the more complex natural conditions. However, whether this requirement is fulfilled is seldom tested explicitly. Here we provide a lab....../field comparison to investigate the identity of an egg-marking signal of ant queens. Our study was based on ant workers resolving conflict over male production by destroying each other's eggs, but leaving queen eggs unharmed. For this, the workers need a proximate cue to discriminate between the two egg types....... Earlier correlative evidence indicated that, in the ant Pachycondyla inversa, the hydrocarbon 3,11-dimethylheptacosane (3,11-diMeC27) is more abundant on the surface of queen-laid eggs. Methodology We first tested the hypothesis that 3,11-diMeC27 functions as a queen egg-marking pheromone using laboratory...

  17. On chip complex signal processing devices using coupled phononic crystal slab resonators and waveguides

    Directory of Open Access Journals (Sweden)

    Saeed Mohammadi

    2011-12-01

    Full Text Available In this paper, we report the evidence for the possibility of achieving complex signal processing functionalities such as multiplexing/demultiplexing at high frequencies using phononic crystal (PnC slabs. It is shown that such functionalities can be obtained by appropriate cross-coupling of PnC resonators and waveguides. PnC waveguides and waveguide-based resonators are realized and cross-coupled through two different methods of mechanical coupling (i.e., direct coupling and side coupling. Waveguide-based PnC resonators are employed because of their high-Q, compactness, large spurious-free spectral ranges, and the possibility of better control over coupling to PnC waveguides. It is shown that by modifying the defects in the formation of the resonators, the frequency of the resonance can be tuned.

  18. Dopamine D1-D2 receptor heteromer signaling pathway in the brain: emerging physiological relevance

    Directory of Open Access Journals (Sweden)

    Hasbi Ahmed

    2011-06-01

    Full Text Available Abstract Dopamine is an important catecholamine neurotransmitter modulating many physiological functions, and is linked to psychopathology of many diseases such as schizophrenia and drug addiction. Dopamine D1 and D2 receptors are the most abundant dopaminergic receptors in the striatum, and although a clear segregation between the pathways expressing these two receptors has been reported in certain subregions, the presence of D1-D2 receptor heteromers within a unique subset of neurons, forming a novel signaling transducing functional entity has been shown. Recently, significant progress has been made in elucidating the signaling pathways activated by the D1-D2 receptor heteromer and their potential physiological relevance.

  19. Role of IL-6 trans-signalling for sleep-wake behaviour of rats : generation of brain-specific sgp130-Fc transgenic mice ; central blockade of IL-6 trans-signalling

    OpenAIRE

    May, Ulrike

    2010-01-01

    The cytokine Interleukin 6 (IL-6) is involved in many biological functions of the immune system, metabolism and the central nervous system, and in the bidirectional communication between these systems. In the brain, IL-6 is considered to affect the modulation of sleep-wake behaviour and synaptic plasticity. IL-6 is further well characterised for its dual role to maintain homeostasis as well as to contribute to inflammatory and autoimmune processes, both in brain and periphery. Signal transduc...

  20. Ultrasound/Magnetic Targeting with SPIO-DOX-Microbubble Complex for Image-Guided Drug Delivery in Brain Tumors

    Science.gov (United States)

    Fan, Ching-Hsiang; Cheng, Yu-Hang; Ting, Chien-Yu; Ho, Yi-Ju; Hsu, Po-Hung; Liu, Hao-Li; Yeh, Chih-Kuang

    2016-01-01

    One of the greatest challenges in the deployment of chemotherapeutic drugs against brain tumors is ensuring that sufficient drug concentrations reach the tumor, while minimizing drug accumulation at undesired sites. Recently, injection of therapeutic agents following blood-brain barrier (BBB) opening by focused ultrasound (FUS) with microbubbles (MBs) has been shown to enhance drug delivery in targeted brain regions. Nevertheless, the distribution and quantitative deposition of agents delivered to the brain are still hard to estimate. Based on our previous work on superparamagnetic iron oxide (SPIO)-loaded MBs, we present a novel theranostic complex of SPIO-Doxorubicin (DOX)-conjugated MB (SD-MB) for drug delivery to the brain. Magnetic labeling of the drug enables direct visualization via magnetic resonance imaging, and also facilitates magnetic targeting (MT) to actively enhance targeted deposition of the drug. In a rat glioma model, we demonstrated that FUS sonication can be used with SD-MBs to simultaneously facilitate BBB opening and allow dual ultrasound/magnetic targeting of chemotherapeutic agent (DOX) delivery. The accumulation of SD complex within brain tumors can be significantly enhanced by MT (25.7 fold of DOX, 7.6 fold of SPIO). The change in relaxation rate R2 (1/T2) within tumors was highly correlated with SD deposition as quantified by high performance liquid chromatography (R2 = 0.93) and inductively coupled plasma-atomic emission spectroscopy (R2 = 0.94), demonstrating real-time monitoring of DOX distribution. Our results suggest that SD-MBs can serve as multifunction agents to achieve advanced molecular theranostics. PMID:27446489

  1. Micro-earthquake signal analysis and hypocenter determination around Lokon volcano complex

    Energy Technology Data Exchange (ETDEWEB)

    Firmansyah, Rizky, E-mail: rizkyfirmansyah@hotmail.com [Geophysical Engineering, Faculty of Mining and Petroleum Engineering, Institut Teknologi Bandung, Bandung, 40132 (Indonesia); Nugraha, Andri Dian, E-mail: nugraha@gf.itb.ac.id [Global Geophysical Group, Faculty of Mining and Petroleum Engineering, Institut Teknologi Bandung, Bandung, 40132 (Indonesia); Kristianto, E-mail: kris@vsi.esdm.go.id [Center for Volcanology and Geological Hazard Mitigation (CVGHM), Geological Agency, Bandung, 40122 (Indonesia)

    2015-04-24

    Mount Lokon is one of five active volcanoes which is located in the North Sulawesi region. Since June 26{sup th}, 2011, standby alert set by the Center for Volcanology and Geological Hazard Mitigation (CVGHM) for this mountain. The Mount Lokon volcano erupted on July 4{sup th}, 2011 and still continuously erupted until August 28{sup th}, 2011. Due to its high seismic activity, this study is focused to analysis of micro-earthquake signal and determine the micro-earthquake hypocenter location around the complex area of Lokon-Empung Volcano before eruption phase in 2011 (time periods of January, 2009 up to March, 2010). Determination of the hypocenter location was conducted with Geiger Adaptive Damping (GAD) method. We used initial model from previous study in Volcan de Colima, Mexico. The reason behind the model selection was based on the same characteristics that shared between Mount Lokon and Colima including andesitic stratovolcano and small-plinian explosions volcanian types. In this study, a picking events was limited to the volcano-tectonics of A and B types, hybrid, long-period that has a clear signal onset, and local tectonic with different maximum S – P time are not more than three seconds. As a result, we observed the micro-earthquakes occurred in the area north-west of Mount Lokon region.

  2. Micro-earthquake signal analysis and hypocenter determination around Lokon volcano complex

    Science.gov (United States)

    Firmansyah, Rizky; Nugraha, Andri Dian; Kristianto

    2015-04-01

    Mount Lokon is one of five active volcanoes which is located in the North Sulawesi region. Since June 26th, 2011, standby alert set by the Center for Volcanology and Geological Hazard Mitigation (CVGHM) for this mountain. The Mount Lokon volcano erupted on July 4th, 2011 and still continuously erupted until August 28th, 2011. Due to its high seismic activity, this study is focused to analysis of micro-earthquake signal and determine the micro-earthquake hypocenter location around the complex area of Lokon-Empung Volcano before eruption phase in 2011 (time periods of January, 2009 up to March, 2010). Determination of the hypocenter location was conducted with Geiger Adaptive Damping (GAD) method. We used initial model from previous study in Volcan de Colima, Mexico. The reason behind the model selection was based on the same characteristics that shared between Mount Lokon and Colima including andesitic stratovolcano and small-plinian explosions volcanian types. In this study, a picking events was limited to the volcano-tectonics of A and B types, hybrid, long-period that has a clear signal onset, and local tectonic with different maximum S - P time are not more than three seconds. As a result, we observed the micro-earthquakes occurred in the area north-west of Mount Lokon region.

  3. Micro-earthquake signal analysis and hypocenter determination around Lokon volcano complex

    International Nuclear Information System (INIS)

    Mount Lokon is one of five active volcanoes which is located in the North Sulawesi region. Since June 26th, 2011, standby alert set by the Center for Volcanology and Geological Hazard Mitigation (CVGHM) for this mountain. The Mount Lokon volcano erupted on July 4th, 2011 and still continuously erupted until August 28th, 2011. Due to its high seismic activity, this study is focused to analysis of micro-earthquake signal and determine the micro-earthquake hypocenter location around the complex area of Lokon-Empung Volcano before eruption phase in 2011 (time periods of January, 2009 up to March, 2010). Determination of the hypocenter location was conducted with Geiger Adaptive Damping (GAD) method. We used initial model from previous study in Volcan de Colima, Mexico. The reason behind the model selection was based on the same characteristics that shared between Mount Lokon and Colima including andesitic stratovolcano and small-plinian explosions volcanian types. In this study, a picking events was limited to the volcano-tectonics of A and B types, hybrid, long-period that has a clear signal onset, and local tectonic with different maximum S – P time are not more than three seconds. As a result, we observed the micro-earthquakes occurred in the area north-west of Mount Lokon region

  4. BRAIN 2.0: Time and Memory Complexity Improvements in the Algorithm for Calculating the Isotope Distribution

    Science.gov (United States)

    Dittwald, Piotr; Valkenborg, Dirk

    2014-04-01

    Recently, an elegant iterative algorithm called BRAIN ( Baffling Recursive Algorithm for Isotopic distributio N calculations) was presented. The algorithm is based on the classic polynomial method for calculating aggregated isotope distributions, and it introduces algebraic identities using Newton-Girard and Viète's formulae to solve the problem of polynomial expansion. Due to the iterative nature of the BRAIN method, it is a requirement that the calculations start from the lightest isotope variant. As such, the complexity of BRAIN scales quadratically with the mass of the putative molecule, since it depends on the number of aggregated peaks that need to be calculated. In this manuscript, we suggest two improvements of the algorithm to decrease both time and memory complexity in obtaining the aggregated isotope distribution. We also illustrate a concept to represent the element isotope distribution in a generic manner. This representation allows for omitting the root calculation of the element polynomial required in the original BRAIN method. A generic formulation for the roots is of special interest for higher order element polynomials such that root finding algorithms and its inaccuracies can be avoided.

  5. Fodrin in centrosomes: implication of a role of fodrin in the transport of gamma-tubulin complex in brain.

    Directory of Open Access Journals (Sweden)

    Sasidharan Shashikala

    Full Text Available Gamma-tubulin is the major protein involved in the nucleation of microtubules from centrosomes in eukaryotic cells. It is present in both cytoplasm and centrosome. However, before centrosome maturation prior to mitosis, gamma-tubulin concentration increases dramatically in the centrosome, the mechanism of which is not known. Earlier it was reported that cytoplasmic gamma-tubulin complex isolated from goat brain contains non-erythroid spectrin/fodrin. The major role of erythroid spectrin is to help in the membrane organisation and integrity. However, fodrin or non-erythroid spectrin has a distinct pattern of localisation in brain cells and evidently some special functions over its erythroid counterpart. In this study, we show that fodrin and γ-tubulin are present together in both the cytoplasm and centrosomes in all brain cells except differentiated neurons and astrocytes. Immunoprecipitation studies in purified centrosomes from brain tissue and brain cell lines confirm that fodrin and γ-tubulin interact with each other in centrosomes. Fodrin dissociates from centrosome just after the onset of mitosis, when the concentration of γ-tubulin attains a maximum at centrosomes. Further it is observed that the interaction between fodrin and γ-tubulin in the centrosome is dependent on actin as depolymerisation of microfilaments stops fodrin localization. Image analysis revealed that γ-tubulin concentration also decreased drastically in the centrosome under this condition. This indicates towards a role of fodrin as a regulatory transporter of γ-tubulin to the centrosomes for normal progression of mitosis.

  6. Structure of PqsD, a Pseudomonas quinolone signal biosynthetic enzyme, in complex with anthranilate.

    Science.gov (United States)

    Bera, Asim K; Atanasova, Vesna; Robinson, Howard; Eisenstein, Edward; Coleman, James P; Pesci, Everett C; Parsons, James F

    2009-09-15

    Pseudomonas quinolone signal (PQS), 2-heptyl-3-hydroxy-4-quinolone, is an intercellular alkyl quinolone signaling molecule produced by the opportunistic pathogen Pseudomonas aeruginosa. Alkyl quinolone signaling is an atypical system that, in P. aeruginosa, controls the expression of numerous virulence factors. PQS is synthesized from the tryptophan pathway intermediate, anthranilate, which is derived either from the kynurenine pathway or from an alkyl quinolone specific anthranilate synthase encoded by phnAB. Anthranilate is converted to PQS by the enzymes encoded by the pqsABCDE operon and pqsH. PqsA forms an activated anthraniloyl-CoA thioester that shuttles anthranilate to the PqsD active site where it is transferred to Cys112 of PqsD. In the only biochemically characterized reaction, a condensation then occurs between anthraniloyl-PqsD and malonyl-CoA or malonyl-ACP, a second PqsD substrate, forming 2,4-dihydroxyquinoline (DHQ). The role PqsD plays in the biosynthesis of other alkyl quinolones, such as PQS, is unclear, though it has been reported to be required for their production. No evidence exists that DHQ is a PQS precursor, however. Here we present a structural and biophysical characterization of PqsD that includes several crystal structures of the enzyme, including that of the PqsD-anthranilate covalent intermediate and the inactive Cys112Ala active site mutant in complex with anthranilate. The structure reveals that PqsD is structurally similar to the FabH and chalcone synthase families of fatty acid and polyketide synthases. The crystallographic asymmetric unit contains a PqsD dimer. The PqsD monomer is composed of two nearly identical approximately 170-residue alphabetaalphabetaalpha domains. The structures show anthranilate-liganded Cys112 is positioned deep in the protein interior at the bottom of an approximately 15 A long channel while a second anthraniloyl-CoA molecule is waiting in the cleft leading to the protein surface. Cys112, His257, and

  7. Cylinder pressure reconstruction based on complex radial basis function networks from vibration and speed signals

    Science.gov (United States)

    Johnsson, Roger

    2006-11-01

    Methods to measure and monitor the cylinder pressure in internal combustion engines can contribute to reduced fuel consumption, noise and exhaust emissions. As direct measurements of the cylinder pressure are expensive and not suitable for measurements in vehicles on the road indirect methods which measure cylinder pressure have great potential value. In this paper, a non-linear model based on complex radial basis function (RBF) networks is proposed for the reconstruction of in-cylinder pressure pulse waveforms. Input to the network is the Fourier transforms of both engine structure vibration and crankshaft speed fluctuation. The primary reason for the use of Fourier transforms is that different frequency regions of the signals are used for the reconstruction process. This approach also makes it easier to reduce the amount of information that is used as input to the RBF network. The complex RBF network was applied to measurements from a 6-cylinder ethanol powered diesel engine over a wide range of running conditions. Prediction accuracy was validated by comparing a number of parameters between the measured and predicted cylinder pressure waveform such as maximum pressure, maximum rate of pressure rise and indicated mean effective pressure. The performance of the network was also evaluated for a number of untrained running conditions that differ both in speed and load from the trained ones. The results for the validation set were comparable to the trained conditions.

  8. Structural Basis for Conserved Regulation and Adaptation of the Signal Recognition Particle Targeting Complex.

    Science.gov (United States)

    Wild, Klemens; Bange, Gert; Motiejunas, Domantas; Kribelbauer, Judith; Hendricks, Astrid; Segnitz, Bernd; Wade, Rebecca C; Sinning, Irmgard

    2016-07-17

    The signal recognition particle (SRP) is a ribonucleoprotein complex with a key role in targeting and insertion of membrane proteins. The two SRP GTPases, SRP54 (Ffh in bacteria) and FtsY (SRα in eukaryotes), form the core of the targeting complex (TC) regulating the SRP cycle. The architecture of the TC and its stimulation by RNA has been described for the bacterial SRP system while this information is lacking for other domains of life. Here, we present the crystal structures of the GTPase heterodimers of archaeal (Sulfolobus solfataricus), eukaryotic (Homo sapiens), and chloroplast (Arabidopsis thaliana) SRP systems. The comprehensive structural comparison combined with Brownian dynamics simulations of TC formation allows for the description of the general blueprint and of specific adaptations of the quasi-symmetric heterodimer. Our work defines conserved external nucleotide-binding sites for SRP GTPase activation by RNA. Structural analyses of the GDP-bound, post-hydrolysis states reveal a conserved, magnesium-sensitive switch within the I-box. Overall, we provide a general model for SRP cycle regulation by RNA. PMID:27241309

  9. Efficient transmission of subthreshold signals in complex networks of spiking neurons.

    Directory of Open Access Journals (Sweden)

    Joaquin J Torres

    Full Text Available We investigate the efficient transmission and processing of weak, subthreshold signals in a realistic neural medium in the presence of different levels of the underlying noise. Assuming Hebbian weights for maximal synaptic conductances--that naturally balances the network with excitatory and inhibitory synapses--and considering short-term synaptic plasticity affecting such conductances, we found different dynamic phases in the system. This includes a memory phase where population of neurons remain synchronized, an oscillatory phase where transitions between different synchronized populations of neurons appears and an asynchronous or noisy phase. When a weak stimulus input is applied to each neuron, increasing the level of noise in the medium we found an efficient transmission of such stimuli around the transition and critical points separating different phases for well-defined different levels of stochasticity in the system. We proved that this intriguing phenomenon is quite robust, as it occurs in different situations including several types of synaptic plasticity, different type and number of stored patterns and diverse network topologies, namely, diluted networks and complex topologies such as scale-free and small-world networks. We conclude that the robustness of the phenomenon in different realistic scenarios, including spiking neurons, short-term synaptic plasticity and complex networks topologies, make very likely that it could also occur in actual neural systems as recent psycho-physical experiments suggest.

  10. Increased Signal Complexity Improves the Breadth of Generalization in Auditory Perceptual Learning

    Directory of Open Access Journals (Sweden)

    David J. Brown

    2013-01-01

    Full Text Available Perceptual learning can be specific to a trained stimulus or optimally generalized to novel stimuli with the breadth of generalization being imperative for how we structure perceptual training programs. Adapting an established auditory interval discrimination paradigm to utilise complex signals, we trained human adults on a standard interval for either 2, 4, or 10 days. We then tested the standard, alternate frequency, interval, and stereo input conditions to evaluate the rapidity of specific learning and breadth of generalization over the time course. In comparison with previous research using simple stimuli, the speed of perceptual learning and breadth of generalization were more rapid and greater in magnitude, including novel generalization to an alternate temporal interval within stimulus type. We also investigated the long term maintenance of learning and found that specific and generalized learning was maintained over 3 and 6 months. We discuss these findings regarding stimulus complexity in perceptual learning and how they can inform the development of effective training protocols.

  11. Centromedian-Parafascicular Complex Deep Brain Stimulation for Tourette Syndrome: A Retrospective Study.

    Science.gov (United States)

    Testini, Paola; Zhao, Cong Z; Stead, Matt; Duffy, Penelope S; Klassen, Bryan T; Lee, Kendall H

    2016-02-01

    Deep brain stimulation (DBS) of the thalamic centromedian/parafascicular (CM-Pf) complex has been reported as a promising treatment for patients with severe, treatment-resistant Tourette syndrome (TS). In this study, safety and clinical outcomes of bilateral thalamic CM-Pf DBS were reviewed in a series of 12 consecutive patients with medically refractory TS, 11 of whom met the criteria of postsurgical follow-up at our institution for at least 2 months. Five patients were followed for a year or longer. Consistent with many patients with TS, all patients had psychiatric comorbidities. Tic severity and frequency were measured by using the Yale Global Tic Severity Scale (YGTSS) over time (average, 26 months) in 10 subjects. One patient was tested at 2-week follow-up only and thus was excluded from group YGTSS analysis. Final YGTSS scores differed significantly from the preoperative baseline score. The average (n=10) improvement relative to baseline in the total score was 54% (95% CI, 37-70); average improvement relative to baseline in the YGTSS Motor tic, Phonic tic, and Impairment subtests was 46% (95% CI, 34-64), 52% (95% CI, 34-72), and 59% (95% CI, 39-78), respectively. There were no intraoperative complications. After surgery, 1 subject underwent wound revision because of a scalp erosion and wound infection; the implanted DBS system was successfully salvaged with surgical revision and combined antibiotic therapy. Stimulation-induced adverse effects did not prevent the use of the DBS system, although 1 subject is undergoing a trial period with the stimulator off. This surgical series adds to the literature on CM-Pf DBS and supports its use as an effective and safe therapeutic option for severe refractory TS. PMID:26848003

  12. Design of complex-valued variable FIR digital filters and its application to the realization of arbitrary sampling rate conversion for complex signals

    OpenAIRE

    Tsui, KM; Chan, SC; Tse, KW

    2005-01-01

    This brief studies the design of complex-valued variable digital filters (CVDFs) and their applications to the efficient arbitrary sample rate conversion for complex signals. The design of CVDFs using either the minimax or least-squares criteria is formulated as a convex optimization problem and solved using the second-order cone programming (SOCP). In addition, linear and convex quadratic inequality constraints can be readily incorporated. Design examples are given to demonstrate the effecti...

  13. DIFFERENTIAL INHIBITION OF MITOCHONDRIAL RESPIRATORY COMPLEXES BY INHALATION OF COMBUSTION SMOKE AND CARBON MONOXIDE, IN VIVO, IN THE RAT BRAIN

    OpenAIRE

    Lee, Heung M; Hallberg, Lance M.; Greeley, George H.; Englander, Ella W.

    2010-01-01

    Combustion smoke contains gases and particulates, which act via hypoxia and cytotoxicity producing mechanisms to injure cells and tissues. While carbon monoxide (CO) is the major toxicant in smoke, its toxicity is exacerbated in presence of other compounds. Here, we examined modulations of mitochondrial and cytosolic energy metabolism by inhalation of combustion smoke versus CO, in vivo, in the rat brain. Measurements revealed reduced activities of respiratory complexes, with greater inhibiti...

  14. Parallel states of pathological Wnt signaling in neonatal brain injury and colon cancer.

    Science.gov (United States)

    Fancy, Stephen P J; Harrington, Emily P; Baranzini, Sergio E; Silbereis, John C; Shiow, Lawrence R; Yuen, Tracy J; Huang, Eric J; Lomvardas, Stavros; Rowitch, David H

    2014-04-01

    In colon cancer, mutation of the Wnt repressor APC (encoding adenomatous polyposis coli) leads to a state of aberrant and unrestricted high-activity signaling. However, the relevance of high Wnt tone in non-genetic human disease is unknown. Here we demonstrate that distinct functional states of Wnt activity determine oligodendrocyte precursor cell (OPC) differentiation and myelination. Mouse OPCs with genetic Wnt dysregulation (high tone) express multiple genes in common with colon cancer, including Lef1, Sp5, Ets2, Rnf43 and Dusp4. Surprisingly, we found that OPCs in lesions of hypoxic human neonatal white matter injury upregulated markers of high Wnt activity and lacked expression of APC. We also found that lack of Wnt repressor tone promoted permanent white matter injury after mild hypoxic insult. These findings suggest a state of pathological high-activity Wnt signaling in human disease tissues that lack predisposing genetic mutation. PMID:24609463

  15. Beyond the brain-Peripheral kisspeptin signaling is essential for promoting endometrial gland development and function

    OpenAIRE

    Silvia León; Daniela Fernadois; Alexandra Sull; Judith Sull; Michele Calder; Kanako Hayashi; Moshmi Bhattacharya; Stephen Power; George A. Vilos; Vilos, Angelos G.; Manuel Tena-Sempere; Babwah, Andy V.

    2016-01-01

    Uterine growth and endometrial gland formation (adenogenesis) and function, are essential for fertility and are controlled by estrogens and other regulators, whose nature and physiological relevance are yet to be elucidated. Kisspeptin, which signals via Kiss1r, is essential for fertility, primarily through its central control of the hypothalamic-pituitary-ovarian axis, but also likely through peripheral actions. Using genetically modified mice, we addressed the contributions of central and p...

  16. Effect of cannabis on glutamate signalling in the brain: A systematic review of human and animal evidence.

    Science.gov (United States)

    Colizzi, Marco; McGuire, Philip; Pertwee, Roger G; Bhattacharyya, Sagnik

    2016-05-01

    Use of cannabis or delta-9-tetrahydrocannabinol (Δ9-THC), its main psychoactive ingredient, is associated with psychotic symptoms or disorder. However, the neurochemical mechanism that may underlie this psychotomimetic effect is poorly understood. Although dopaminergic dysfunction is generally recognized as the final common pathway in psychosis, evidence of the effects of Δ9-THC or cannabis use on dopaminergic measures in the brain is equivocal. In fact, it is thought that cannabis or Δ9-THC may not act on dopamine firing directly but indirectly by altering glutamate neurotransmission. Here we systematically review all studies examining acute and chronic effects of cannabis or Δ9-THC on glutamate signalling in both animals and man. Limited research carried out in humans tends to support the evidence that chronic cannabis use reduces levels of glutamate-derived metabolites in both cortical and subcortical brain areas. Research in animals tends to consistently suggest that Δ9-THC depresses glutamate synaptic transmission via CB1 receptor activation, affecting glutamate release, inhibiting receptors and transporters function, reducing enzyme activity, and disrupting glutamate synaptic plasticity after prolonged exposure. PMID:26987641

  17. Treatment with gelsolin reduces brain inflammation and apoptotic signaling in mice following thermal injury

    Directory of Open Access Journals (Sweden)

    Sheng Zhi-Yong

    2011-09-01

    Full Text Available Abstract Background Burn survivors develop long-term cognitive impairment with increased inflammation and apoptosis in the brain. Gelsolin, an actin-binding protein with capping and severing activities, plays a crucial role in the septic response. We investigated if gelsolin infusion could attenuate neural damage in burned mice. Methods Mice with 15% total body surface area burns were injected intravenously with bovine serum albumin as placebo (2 mg/kg, or with low (2 mg/kg or high doses (20 mg/kg of gelsolin. Samples were harvested at 8, 24, 48 and 72 hours postburn. The immune function of splenic T cells was analyzed. Cerebral pathology was examined by hematoxylin/eosin staining, while activated glial cells and infiltrating leukocytes were detected by immunohistochemistry. Cerebral cytokine mRNAs were further assessed by quantitative real-time PCR, while apoptosis was evaluated by caspase-3. Neural damage was determined using enzyme-linked immunosorbent assay of neuron-specific enolase (NSE and soluble protein-100 (S-100. Finally, cerebral phospho-ERK expression was measured by western blot. Results Gelsolin significantly improved the outcomes of mice following major burns in a dose-dependent manner. The survival rate was improved by high dose gelsolin treatment compared with the placebo group (56.67% vs. 30%. Although there was no significant improvement in outcome in mice receiving low dose gelsolin (30%, survival time was prolonged against the placebo control (43.1 ± 4.5 h vs. 35.5 ± 5.0 h; P Conclusion Exogenous gelsolin infusion improves survival of mice following major burn injury by partially attenuating inflammation and apoptosis in brain, and by enhancing peripheral T lymphocyte function as well. These data suggest a novel and effective strategy to combat excessive neuroinflammation and to preserve cognition in the setting of major burns.

  18. Multiple brain parenchymal neurocysticercosis with extraocular muscle cysticercosis affecting levator palpebral superioris and superior rectus complex: an unusual association

    OpenAIRE

    Verma, Rajesh; Jaiswal, Anupam

    2013-01-01

    An 8-year-old girl presented to the neurology department with a complaint of insidious onset of left-sided ptosis and restricted elevation of the left eye. A CT scan orbit and brain revealed a ring-enhancing lesion in the levator palpebral superioris (LPS) and superior rectus (SR) muscle complex of the left eye and left parietal and right temporal region. She was started on steroid, followed by albendazole with improvement. The LPS/SR complex is the least common site of involvement among extr...

  19. Posture-related changes in brain functional connectivity as assessed by wavelet phase coherence of NIRS signals in elderly subjects.

    Science.gov (United States)

    Wang, Bitan; Zhang, Ming; Bu, Lingguo; Xu, Liwei; Wang, Wei; Li, Zengyong

    2016-10-01

    Postural instability and falls are commonly seen because of aging and motor disabilities. This study aims to assess the posture-related changes in brain functional connectivity by wavelet phase coherence (WPCO) of oxyhemoglobin concentration change (Δ[HbO2]) signals measured through near-infrared spectroscopy (NIRS) in elderly subjects. The NIRS signals were continuously recorded from the prefrontal cortex and sensorimotor cortical areas in 39 healthy elderly subjects and 22 young healthy subjects during 20min resting and 10min standing states. Eight connection types were obtained from the recorded brain areas. The WPCO were calculated in five frequency intervals in each channel pair as follows: I, 0.6-2Hz; II, 0.145-0.6Hz; III, 0.052-0.145Hz; IV, 0.021-0.052Hz; and V, 0.0095-0.021Hz. Results show that posture change and age significantly interacts with the right prefrontal cortex (PFC) and left sensorimotor cortex (SMC) connectivity in interval V (F=5.010, p=0.028). The left and right PFC connectivity in interval I, the left and right SMC connectivity in interval IV, and the connectivity in interval V, including right PFC and right SMC connectivity, left PFC and left SMC connectivity, and right PFC and left SMC connectivity, showed a significant difference between the Group Elderly and Group Young in response to posture change (p<0.05). This study provides new insight into the mechanism of posture control, and results may be useful in assessing the risk of postural instability in aged persons. PMID:27335218

  20. WNT/FZD signaling : an odyssey from molecular pharmacology to brain (patho)physiology

    OpenAIRE

    Dijksterhuis, Jacomijn P.

    2015-01-01

    The 19 members of the lipoglycoprotein family of WNTs interact with the highly conserved cysteine-rich domain (CRD) of ten members of the Frizzled (FZD1-10) family. The seven transmembrane-spanning surface receptors are listed as G protein-coupled receptors and are known to interact with heterotrimeric G proteins as well as the scaffolding protein disheveled. Upon ligand binding, activation of β-catenin-dependent and/or –independent pathways are induced. The WNT/Frizzled signaling pathway is ...

  1. Task-Dependent Signal Variations in EEG Error-Related Potentials for Brain-Computer Interfaces

    OpenAIRE

    Iturrate, Inaki; Montesano, Luis; Minguez, Javier

    2013-01-01

    Objective. A major difficulty of brain–computer interface (BCI) technology is dealing with the noise of EEG and its signal variations. Previous works studied time-dependent non-stationarities for BCIs in which the user's mental task was independent of the device operation (e.g., the mental task was motor imagery and the operational task was a speller). However, there are some BCIs, such as those based on error-related potentials, where the mental and operational tasks are dependent (e.g., the...

  2. From PII Signaling to Metabolite Sensing: A Novel 2-Oxoglutarate Sensor That Details PII - NAGK Complex Formation

    OpenAIRE

    Lüddecke, Jan; Forchhammer, Karl

    2013-01-01

    The widespread PII signal transduction proteins are known for integrating signals of nitrogen and energy supply and regulating cellular behavior by interacting with a multitude of target proteins. The PII protein of the cyanobacterium Synechococcus elongatus forms complexes with the controlling enzyme of arginine synthesis, N-acetyl-L-glutamate kinase (NAGK) in a 2-oxoglutarate- and ATP/ADP-dependent manner. Fusing NAGK and PII proteins to either CFP or YFP yielded a FRET sensor that specific...

  3. RHINO forms a stoichiometric complex with the 9-1-1 checkpoint clamp and mediates ATR-Chk1 signaling

    OpenAIRE

    Lindsey-Boltz, Laura A.; Kemp, Michael G.; Capp, Christopher; Sancar, Aziz

    2015-01-01

    The ATR-Chk1 signaling pathway mediates cellular responses to DNA damage and replication stress and is composed of a number of core factors that are conserved throughout eukaryotic organisms. However, humans and other higher eukaryotic species possess additional factors that are implicated in the regulation of this signaling network but that have not been extensively studied. Here we show that RHINO (for Rad9, Rad1, Hus1 interacting nuclear orphan) forms complexes with both the 9-1-1 checkpoi...

  4. Regulatory Networks and Complex Interactions between the Insulin and Angiotensin II Signalling Systems: Models and Implications for Hypertension and Diabetes

    OpenAIRE

    Çizmeci, Deniz; Arkun, Yaman

    2013-01-01

    Regulatory Networks and Complex Interactions between the Insulin and Angiotensin II Signalling Systems: Models and Implications for Hypertension and Diabetes Deniz Cizmeci, Yaman Arkun* Department of Chemical and Biological Engineering, Koc University, Istanbul, Turkey Abstract The cross-talk between insulin and angiotensin II signalling pathways plays a significant role in the co-occurrence of diabetes and hypertension. We developed a mathematical model of the system of ...

  5. Dopaminergic and brain-derived neurotrophic factor signalling in inbred mice exposed to a restricted feeding schedule.

    Science.gov (United States)

    Gelegen, C; van den Heuvel, J; Collier, D A; Campbell, I C; Oppelaar, H; Hessel, E; Kas, M J H

    2008-07-01

    Increased physical activity and decreased motivation to eat are common features in anorexia nervosa. We investigated the development of these features and the potential implication of brain-derived neurotrophic factor (BDNF) and dopaminergic signalling in their development in C57BL/6J and A/J inbred mice, using the 'activity-based anorexia' model. In this model, mice on a restricted-feeding schedule are given unlimited access to running wheels. We measured dopamine receptor D2 and BDNF expression levels in the caudate putamen and the hippocampus, respectively, using in situ hybridization. We found that in response to scheduled feeding, C57BL/6J mice reduced their running wheel activity and displayed food anticipatory activity prior to food intake from day 2 of scheduled feeding as an indication of motivation to eat. In contrast, A/J mice increased running wheel activity during scheduled feeding and lacked food anticipatory activity. These were accompanied by increased dopamine receptor D2 expression in the caudate putamen and reduced BDNF expression in the hippocampus. Consistent with human linkage and association studies on BDNF and dopamine receptor D2 in anorexia nervosa, our study shows that dopaminergic and BDNF signalling are altered as a function of susceptibility to activity-based anorexia. Differences in gene expression and behaviour between A/J and C57BL/6J mice indicate that mouse genetic mapping populations based on these progenitor lines are valuable for identifying molecular determinants of anorexia-related traits. PMID:18363853

  6. Brain Basics

    Medline Plus

    Full Text Available ... Life Brain Basics in Real Life—How Depression affects the Brain Meet Sarah Sarah is a middle-aged woman ... new memories. hypothalmic-pituitary-adrenal (HPA) axis —A brain-body ... stress. impulse —An electrical communication signal sent between neurons ...

  7. Sevoflurane-Sulfobutylether-β-Cyclodextrin Complex: Preparation, Characterization, Cellular Toxicity, Molecular Modeling and Blood-Brain Barrier Transport Studies

    Directory of Open Access Journals (Sweden)

    Sergey Shityakov

    2015-06-01

    Full Text Available The objective of the present investigation was to study the ability of sulfobutylether-β-cyclodextrin (SBEβCD to form an inclusion complex with sevoflurane (SEV, a volatile anesthetic with poor water solubility. The inclusion complex was prepared, characterized and its cellular toxicity and blood-brain barrier (BBB permeation potential of the formulated SEV have also been examined for the purpose of controlled drug delivery. The SEV-SBEβCD complex was nontoxic to the primary brain microvascular endothelial (pEND cells at a clinically relevant concentration of sevoflurane. The inclusion complex exhibited significantly higher BBB permeation profiles as compared with the reference substance (propranolol concerning calculated apparent permeability values (Papp. In addition, SEV binding affinity to SBEβCD was confirmed by a minimal Gibbs free energy of binding (ΔGbind value of −1.727 ± 0.042 kcal·mol−1 and an average binding constant (Kb of 53.66 ± 9.24 mM indicating rapid drug liberation from the cyclodextrin amphiphilic cavity.

  8. Sevoflurane-Sulfobutylether-β-Cyclodextrin Complex: Preparation, Characterization, Cellular Toxicity, Molecular Modeling and Blood-Brain Barrier Transport Studies.

    Science.gov (United States)

    Shityakov, Sergey; Puskás, István; Pápai, Katalin; Salvador, Ellaine; Roewer, Norbert; Förster, Carola; Broscheit, Jens-Albert

    2015-01-01

    The objective of the present investigation was to study the ability of sulfobutylether-β-cyclodextrin (SBEβCD) to form an inclusion complex with sevoflurane (SEV), a volatile anesthetic with poor water solubility. The inclusion complex was prepared, characterized and its cellular toxicity and blood-brain barrier (BBB) permeation potential of the formulated SEV have also been examined for the purpose of controlled drug delivery. The SEV-SBEβCD complex was nontoxic to the primary brain microvascular endothelial (pEND) cells at a clinically relevant concentration of sevoflurane. The inclusion complex exhibited significantly higher BBB permeation profiles as compared with the reference substance (propranolol) concerning calculated apparent permeability values (Papp). In addition, SEV binding affinity to SBEβCD was confirmed by a minimal Gibbs free energy of binding (ΔGbind) value of -1.727 ± 0.042 kcal·mol-1 and an average binding constant (Kb) of 53.66 ± 9.24 mM indicating rapid drug liberation from the cyclodextrin amphiphilic cavity. PMID:26046323

  9. [Asthenic syndrome in clinical course of acute period of brain concussion during complex treatment using nootropic agents].

    Science.gov (United States)

    Tkachov, A V

    2008-01-01

    The comparative analysis of a complex examination of 108 persons aged from 16 till 60 years in acute period of closed craniocerebral injury (CCCT) has been done. Every participants have been divided into 2 groups depending on a nootrop medication they receive in a complex treatment. A control group consisted of 30 practically healthy people. Objective examination by means of tests was done on the 1-st, 10-th that 30-th day of treatment. Patients of 1-st (37 persons) group received piracetam in complex treatment and patients of the 2-nd group (71 persons) pramistar. Patients of the first group received a base treatment (analgetics, tranquilizers, vitamins of group B, magnesium sulfate, diuretic preparations) as well as piracetam at dosage 0.2, two tablets three times per day. The Patients of the 2-nd group received a base treatment as well as pramistar at dosage 0.6, one tablet 2 times per day. Specially developed multiaspects scales and questionnaires, MRT of the brain and EEG have been used for objectification of patient, complaints. During a complex clinico-neuropsychological examination it was found that all cases of concussion of the brain are accompanied by those or other asthenic disorders. PMID:19145827

  10. Massively parallel signal processing using the graphics processing unit for real-time brain-computer interface feature extraction

    Directory of Open Access Journals (Sweden)

    J. Adam Wilson

    2009-07-01

    Full Text Available The clock speeds of modern computer processors have nearly plateaued in the past five years. Consequently, neural prosthetic systems that rely on processing large quantities of data in a short period of time face a bottleneck, in that it may not be possible to process all of the data recorded from an electrode array with high channel counts and bandwidth, such as electrocorticographic grids or other implantable systems. Therefore, in this study a method of using the processing capabilities of a graphics card (GPU was developed for real-time neural signal processing of a brain-computer interface (BCI. The NVIDIA CUDA system was used to offload processing to the GPU, which is capable of running many operations in parallel, potentially greatly increasing the speed of existing algorithms. The BCI system records many channels of data, which are processed and translated into a control signal, such as the movement of a computer cursor. This signal processing chain involves computing a matrix-matrix multiplication (i.e., a spatial filter, followed by calculating the power spectral density on every channel using an auto-regressive method, and finally classifying appropriate features for control. In this study, the first two computationally-intensive steps were implemented on the GPU, and the speed was compared to both the current implementation and a CPU-based implementation that uses multi-threading. Significant performance gains were obtained with GPU processing: the current implementation processed 1000 channels in 933 ms, while the new GPU method took only 27 ms, an improvement of nearly 35 times.

  11. Massively Parallel Signal Processing using the Graphics Processing Unit for Real-Time Brain-Computer Interface Feature Extraction.

    Science.gov (United States)

    Wilson, J Adam; Williams, Justin C

    2009-01-01

    The clock speeds of modern computer processors have nearly plateaued in the past 5 years. Consequently, neural prosthetic systems that rely on processing large quantities of data in a short period of time face a bottleneck, in that it may not be possible to process all of the data recorded from an electrode array with high channel counts and bandwidth, such as electrocorticographic grids or other implantable systems. Therefore, in this study a method of using the processing capabilities of a graphics card [graphics processing unit (GPU)] was developed for real-time neural signal processing of a brain-computer interface (BCI). The NVIDIA CUDA system was used to offload processing to the GPU, which is capable of running many operations in parallel, potentially greatly increasing the speed of existing algorithms. The BCI system records many channels of data, which are processed and translated into a control signal, such as the movement of a computer cursor. This signal processing chain involves computing a matrix-matrix multiplication (i.e., a spatial filter), followed by calculating the power spectral density on every channel using an auto-regressive method, and finally classifying appropriate features for control. In this study, the first two computationally intensive steps were implemented on the GPU, and the speed was compared to both the current implementation and a central processing unit-based implementation that uses multi-threading. Significant performance gains were obtained with GPU processing: the current implementation processed 1000 channels of 250 ms in 933 ms, while the new GPU method took only 27 ms, an improvement of nearly 35 times. PMID:19636394

  12. Genome-wide identification of Bcl11b gene targets reveals role in brain-derived neurotrophic factor signaling.

    Directory of Open Access Journals (Sweden)

    Bin Tang

    Full Text Available B-cell leukemia/lymphoma 11B (Bcl11b is a transcription factor showing predominant expression in the striatum. To date, there are no known gene targets of Bcl11b in the nervous system. Here, we define targets for Bcl11b in striatal cells by performing chromatin immunoprecipitation followed by high-throughput sequencing (ChIP-seq in combination with genome-wide expression profiling. Transcriptome-wide analysis revealed that 694 genes were significantly altered in striatal cells over-expressing Bcl11b, including genes showing striatal-enriched expression similar to Bcl11b. ChIP-seq analysis demonstrated that Bcl11b bound a mixture of coding and non-coding sequences that were within 10 kb of the transcription start site of an annotated gene. Integrating all ChIP-seq hits with the microarray expression data, 248 direct targets of Bcl11b were identified. Functional analysis on the integrated gene target list identified several zinc-finger encoding genes as Bcl11b targets, and further revealed a significant association of Bcl11b to brain-derived neurotrophic factor/neurotrophin signaling. Analysis of ChIP-seq binding regions revealed significant consensus DNA binding motifs for Bcl11b. These data implicate Bcl11b as a novel regulator of the BDNF signaling pathway, which is disrupted in many neurological disorders. Specific targeting of the Bcl11b-DNA interaction could represent a novel therapeutic approach to lowering BDNF signaling specifically in striatal cells.

  13. Cocaine and mitochondria-related signaling in the brain: A mechanistic view and future directions.

    Science.gov (United States)

    de Oliveira, Marcos Roberto; Jardim, Fernanda Rafaela

    2016-01-01

    Cocaine is extensively used as a psychostimulant among subjects at different ages worldwide. Cocaine causes neuronal dysfunction and, consequently, negatively affects human behavior and decreases life quality severely. Cocaine acts through diverse mechanisms, including mitochondrial impairment and activation of cell signaling pathways associated to stress response. There is some controversy regarding the effect of cocaine in inducing cell death through apoptosis in different experimental models. The aim of the present work is to discuss data associated to the mitochondrial consequences of cocaine exposure of mammalian cells in several experimental models from in vitro to in vivo, including postmortem human tissue analyses. Furthermore, future directions are proposed in order to serve as a suggestive guide in relation to the next steps towards the complete elucidation of the mechanisms of toxicity elicited by cocaine upon mitochondria of neuronal cells. PMID:26707813

  14. Signaling through MyD88 regulates leukocyte recruitment after brain injury

    DEFF Research Database (Denmark)

    Babcock, Alicia A; Toft-Hansen, Henrik; Owens, Trevor

    2008-01-01

    protein that transmits signals from TLRs and receptors for IL-1 and IL-18, regulates leukocyte infiltration into the stab-injured entorhinal cortex (EC) and into sites of axonal degeneration in the denervated hippocampus. We have previously established the kinetics of leukocyte entry into the denervated...... hippocampus. We now show that significant leukocyte entry into the EC occurs within 3-12 h of stab injury. Whereas T cells showed small, gradual increases over 8 days, macrophage infiltration was pronounced and peaked within 12-24 h. MyD88 deficiency significantly reduced macrophage and T cell recruitment to....... Transcripts for TNF-alpha, IL-1beta, and CCL2, which increased >50-fold after stab injury in C57BL/6 mice at the time of peak expression, were severely reduced in injured MyD88 knockout mice. Leukocyte recruitment and gene expression were unaffected in TLR2-deficient or TLR4 mutant mice. No significant...

  15. Bifurcation mechanisms of regular and chaotic network signaling in brain astrocytes

    Science.gov (United States)

    Matrosov, V. V.; Kazantsev, V. B.

    2011-06-01

    Bifurcation mechanisms underlying calcium oscillations in the network of astrocytes are investigated. Network model includes the dynamics of intracellular calcium concentration and intercellular diffusion of inositol 1,4,5-trisphosphate through gap junctions. Bifurcation analysis of underlying nonlinear dynamical system is presented. Parameter regions and principle bifurcation boundaries have been delineated and described. We show how variations of the diffusion rate can lead to generation of network calcium oscillations in originally nonoscillating cells. Different scenarios of regular activity and its transitions to chaotic dynamics have been obtained. Then, the bifurcations have been associated with statistical characteristics of calcium signals showing that different bifurcation scenarios yield qualitative changes in experimentally measurable quantities of the astrocyte activity, e.g., statistics of calcium spikes.

  16. KINESTHETIC IMAGERY TRAINING OF FORCEFUL MUSCLE CONTRACTIONS INCREASES BRAIN SIGNAL AND MUSCLE STRENGTH

    Directory of Open Access Journals (Sweden)

    Wan X Yao

    2013-09-01

    Full Text Available The purpose of this study was to compare the effect of training using internal imagery (IMI; also known as kinesthetic imagery or first person imagery with that of external imagery (EMI; also known as third-person visual imagery of strong muscle contractions on voluntary muscle strengthening. Eighteen young, healthy subjects were randomly assigned to one of three groups (6 in each group: internal motor imagery (IMI, external motor imagery (EMI, or a no-practice control (CTRL group. Training lasted for 6 weeks (~15 min/day, 5 days/week. The participants’ right arm elbow-flexion strength, muscle electrical activity and movement-related cortical potential (MRCP were evaluated before and after training. Only the IMI group showed significant strength gained (10.8% while the EMI (4.8% and CTRL (-3.3% groups did not. Only the IMI group showed a significant elevation in MRCP on scalp locations over both the primary motor (M1 and supplementary motor cortices (EMI group over M1 only and this increase was significantly greater than that of EMI and CTRL groups. These results suggest that training by IMI of forceful muscle contractions was effective in improving voluntary muscle strength without physical exercise. We suggest that the IMI training likely strengthened brain-to-muscle (BTM command that may have improved motor unit recruitment and activation, and led to greater muscle output. Training by internal motor imagery of forceful muscle contractions may change the activity level of cortical motor control network, which may translate into greater descending command to the target muscle and increase its strength.

  17. Signaling pathways regulating production of hyaluronic acid in pig oocyte-cumulus cell-complexes

    Czech Academy of Sciences Publication Activity Database

    Procházka, Radek; Nagyová, Eva

    Luxembourg: Recherches Scientifiques Luxembourg, 2006. s. 647. [Cell Signaling World 2006, Signal Transduction Pathways therapeutic targets. 25.01.2006-28.01.2006, Luxembourg] R&D Projects: GA ČR GA523/04/0574 Institutional research plan: CEZ:AV0Z50450515 Keywords : signaling pathways Subject RIV: EB - Genetics ; Molecular Biology

  18. Effect of lighting conditions on brain network complexity associated with response learning.

    Science.gov (United States)

    Fidalgo, Camino; Conejo, Nélida M; González-Pardo, Héctor; Arias, Jorge L

    2013-10-25

    Several studies have reported the brain regions involved in response learning. However, there is discrepancy regarding the lighting conditions in the experimental setting (i.e. under dark or light conditions). In this regard, it would be relevant to know if the presence/absence of visual cues in the environment has any effect in the brain networks involved in a response learning task. Animals were trained in a water T-maze under two different lighting conditions (light versus dark). All subjects reached the learning criterion of 80% correct arm choices. Quantitative cytochrome oxidase (CO) histochemistry was used as a metabolic brain mapping technique. Our results show that the ventral hippocampus and the parietal cortex are associated with the acquisition of a response learning task regardless of lighting conditions. In addition, when the same task is run in the dark, widespread recruitment of structures involving cortical, limbic and striatal regions was found. PMID:24084195

  19. Does cannabis affect dopaminergic signaling in the human brain? A systematic review of evidence to date.

    Science.gov (United States)

    Sami, Musa Basser; Rabiner, Eugenii A; Bhattacharyya, Sagnik

    2015-08-01

    A significant body of epidemiological evidence has linked psychotic symptoms with both acute and chronic use of cannabis. Precisely how these effects of THC are mediated at the neurochemical level is unclear. While abnormalities in multiple pathways may lead to schizophrenia, an abnormality in dopamine neurotransmission is considered to be the final common abnormality. One would thus expect cannabis use to be associated with dopamine signaling alterations. This is the first systematic review of all studies, both observational as well as experimental, examining the acute as well as chronic effect of cannabis or its main psychoactive ingredient, THC, on the dopamine system in man. We aimed to review all studies conducted in man, with any reported neurochemical outcomes related to the dopamine system after cannabis, cannabinoid or endocannabinoid administration or use. We identified 25 studies reporting outcomes on over 568 participants, of which 244 participants belonged to the cannabis/cannabinoid exposure group. In man, there is as yet little direct evidence to suggest that cannabis use affects acute striatal dopamine release or affects chronic dopamine receptor status in healthy human volunteers. However some work has suggested that acute cannabis exposure increases dopamine release in striatal and pre-frontal areas in those genetically predisposed for, or at clinical high risk of psychosis. Furthermore, recent studies are suggesting that chronic cannabis use blunts dopamine synthesis and dopamine release capacity. Further well-designed studies are required to definitively delineate the effects of cannabis use on the dopaminergic system in man. PMID:26068702

  20. Comparative Analysis of Signal Intensity and Apparent Diffusion Coefficient at Varying b-values in the Brain : Diffusion Weighted-Echo Planar Image (T2 and FLAIR) Sequence

    International Nuclear Information System (INIS)

    Diffusion-weighted imaging (DWI) has been demonstrated to be a practical method for the diagnosis of various brain diseases such as acute infarction, brain tumor, and white matter disease. In this study, we used two techniques to examine the average signal intensity (SI) and apparent diffusion coefficient (ADC) of the brains of patients who ranged in age from 10 to 60 years. Our results indicated that the average SI was the highest in amygdala (as derived from DWI), whereas that in the cerebrospinal fluid was the lowest. The average ADC was the highest in the cerebrospinal fluid, whereas the lowest measurement was derived from the pons. The average SI and ADC were higher in T2-DW-EPI than in FLAIR-DW-EPI. The higher the b-value, the smaller the average difference in both imaging techniques; the lower the b-value, the greater the average difference. Also, comparative analysis of the brains of patients who had experienced cerebral infarction showed no distinct lesion in the general MR image over time. However, there was a high SI in apparent weighted images. Analysis of other brain diseases (e.g., bleeding, acute, subacute, chronic infarction) indicated SI variance in accordance with characteristics of the two techniques. The higher the SI, the lower the ADC. Taken together, the value of SI and ADC in accordance with frequently occurring areas and various brain disease varies based on the b-value and imaging technique. Because they provide additional useful information in the diagnosis and treatment of patients with various brain diseases through signal recognition, the proper imaging technique and b-value are important for the detection and interpretation of subacute stroke and other brain diseases.

  1. Comment on 'Interpretation of the Lempel-Ziv Complexity Measure in the context of Biomedical Signal Analysis'

    CERN Document Server

    Balasubramanian, Karthi

    2013-01-01

    In this Communication, we express our reservations on some aspects of the interpretation of the Lempel-Ziv Complexity measure (LZ) by Mateo et al. in "Interpretation of the Lempel-Ziv complexity measure in the context of biomedical signal analysis," IEEE Trans. Biomed. Eng., vol. 53, no. 11, pp. 2282-2288, Nov. 2006. In particular, we comment on the dependence of the LZ complexity measure on number of harmonics, frequency content and amplitude modulation. We disagree with the following statements made by Mateo et al. 1. "LZ is not sensitive to the number of harmonics in periodic signals." 2. "LZ increases as the frequency of a sinusoid increases." 3. "Amplitude modulation of a signal doesnot result in an increase in LZ." We show the dependence of LZ complexity measure on harmonics and amplitude modulation by using a modified version of the synthetic signal that has been used in the original paper. Also, the second statement is a generic statement which is not entirely true. This is true only in the low freque...

  2. Fixed-Point Algorithms for the Blind Separation of Arbitrary Complex-Valued Non-Gaussian Signal Mixtures

    Directory of Open Access Journals (Sweden)

    Douglas Scott C

    2007-01-01

    Full Text Available We derive new fixed-point algorithms for the blind separation of complex-valued mixtures of independent, noncircularly symmetric, and non-Gaussian source signals. Leveraging recently developed results on the separability of complex-valued signal mixtures, we systematically construct iterative procedures on a kurtosis-based contrast whose evolutionary characteristics are identical to those of the FastICA algorithm of Hyvarinen and Oja in the real-valued mixture case. Thus, our methods inherit the fast convergence properties, computational simplicity, and ease of use of the FastICA algorithm while at the same time extending this class of techniques to complex signal mixtures. For extracting multiple sources, symmetric and asymmetric signal deflation procedures can be employed. Simulations for both noiseless and noisy mixtures indicate that the proposed algorithms have superior finite-sample performance in data-starved scenarios as compared to existing complex ICA methods while performing about as well as the best of these techniques for larger data-record lengths.

  3. Evaluation of 18F-BCPP-EF for mitochondrial complex 1 imaging in the brain of conscious monkeys using PET

    International Nuclear Information System (INIS)

    We have reported on the development of a novel PET probe, 18F-2-tert-butyl-4-chloro-5-{6-[2-(2-fluoroethoxy)-ethoxy] -pyridin-3-ylmethoxy}-2H-pyridazin-3-one (18F-BCPP-EF), for quantitative imaging of mitochondrial complex 1 (MC-1) activity in the brain of the living rat. For clinical application in humans, translational research in the monkey was conducted. PET measurements with 18F-BCPP-EF were performed in young and old monkeys (Macaca mulatta) in a conscious state with arterial blood sampling. The binding specificity of 18F-BCPP-EF was evaluated with rotenone, a specific MC-1 inhibitor, in young animals. The binding (total distribution volume, VT) of 18F-BCPP-EF was calculated using Logan graphical analysis, and one-tissue compartment model (1-TC) and two-tissue compartment model (2-TC) analyses using a metabolite-corrected plasma input function. F-BCPP-EF was rapidly taken up into the brain just after intravenous injection, peaked between 10 and 20 min after injection, and was then gradually eliminated. The 2-TC analysis provided a better fit than the 1-TC analysis, and the VT values from the 2-TC analysis correlated well with those from the Logan plot. With predosing with rotenone, 18F-BCPP-EF showed a higher uptake peak in the brain, followed by more rapid elimination thereafter than in the vehicle condition, resulting in significant reductions in 2-TC VT values in all regions. In old animals, the kinetics of 18F-BCPP-EF were slightly slower with lower peak levels than in young animals, resulting age-related reductions in 18F-BCPP-EF binding in all brain regions. The present study demonstrated that 18F-BCPP-EF may be a potential PET probe for quantitative imaging MC-1 activity in the living brain using PET. (orig.)

  4. Volume of discrete brain structures in complex dissociative disorders : preliminary findings

    NARCIS (Netherlands)

    Ehling, T.; Nijenhuis, E. R. S.; Krikke, A. P.; DeKloet, ER; Vermetten, E

    2007-01-01

    Based on findings in traumatized animals and patients with posttraumatic stress disorder, and on traumatogenic models of complex dissociative disorders, it was hypothesized that (1) patients with complex dissociative disorders have smaller volumes of hippocampus, parahippocampal gyrus, and amygdala

  5. MRI of the normal brain from early childhood to middle age. Pt. 2. Age dependence of signal intensity changes on T2-weighted images

    International Nuclear Information System (INIS)

    We examined 66 healthy volunteers aged 4 to 50 years by magnetic resonance imaging (MRI) and the signal intensity was measured on T2-weighted images in numerous sites and correlated with age and sex. Using distilled water and cerebrospinal fluid (CSF) as references on each slice, we calculated the signal intensities of the brain structures. Calculated ratios between structures did not change with age, except for those of the globus pallidus and thalamus, in which the signal intensities decreased more rapidly. The signal intensities of other brain structures changed equally but this could not be discerned visually and quantitative measurements were required. The signal intensities in the white and deep grey matter decreased rapidly in the first decade and then gradually to reach a plateau after the age of 18 years. Maturation of the brain thus seems to continue until near the end of the second decade of life. No sex differences were found. Quantitative analysis requires intensity references. The CSF in the tips of the frontal horns seems to be as reliable as an external fluid reference for intensity, and can be used in routine examinations provided the frontal horns are large enough to avoid partial volume effect. (orig.)

  6. Self-organized Critical Model Based on Complex Brain Networks with Hierarchical Organization

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ying-Yue; ZHANG Gui-Qing; YANG Qiu-Ying; CHEN Tian-Lun

    2008-01-01

    The dynamical behavior in the cortical brain network of macaque is studied by modelling each cortical area with a subnetwork of interacting excitable neurons.We find that the avalanche of our model on different levels exhibits power-law.Furthermore the power-law exponent of the distribution and the average avalanche Size are affected by the topology of the network.

  7. Signal recognition particle receptor is a complex that contains two distinct polypeptide chains

    International Nuclear Information System (INIS)

    Signal recognition particle (SRP) and SRP receptor are known to be essential components of the cellular machinery that targets nascent secretory proteins to the endoplasmic reticulum (ER) membrane. Here the authors report that the SRP receptor contains, in addition to the previously identified and sequenced 69-kD polypeptide (α-subunit, SRα), a 30-kD β-subunit SRβ). When SRP receptor was purified by SRP-Sepharose affinity chromatography, they observed the co-purification of two other ER membrane proteins. Both proteins are ∼30 kD in size and are immunologically distinct from each other, as well as from SRα and SRP proteins. One of the 30-kD proteins (SRβ) forms a tight complex with SRα in detergent solution that is stable to high salt and can be immunoprecipitated with antibodies to either SRα or SRβ. Both subunits are present in the ER membrane in equimolar amounts and co-fractionate in constant stoichiometry when rough and smooth liver microsomes are separated on sucrose gradients. They therefore conclude that SRβ is an integral component of SRP receptor. The presence of SRβ was previously masked by proteolytic breakdown products of SRα observed by others and by the presence of another 30-kD ER membrane protein (mp30) which co-purifies with SRα. Mp30 binds to SRP-Sepharose directly and is present in the ER membrane in several-fold molar excess of SRα and SRβ. The affinity of mp30 for SRP suggests that it may serve a yet unknown function in protein translocation

  8. Brain mapping

    Directory of Open Access Journals (Sweden)

    Blaž Koritnik

    2004-08-01

    Full Text Available Cartography of the brain ("brain mapping" aims to represent the complexities of the working brain in an understandable and usable way. There are four crucial steps in brain mapping: (1 acquiring data about brain structure and function, (2 transformation of data into a common reference, (3 visualization and interpretation of results, and (4 databasing and archiving. Electrophysiological and functional imaging methods provide information about function of the human brain. A prerequisite for multisubject, multidimensional and multimodal mapping is transformation of individual images to match a standard brain template. To produce brain maps, color, contours, and other visual cues are used to differentiate metabolic rates, electrical field potentials, receptor densities, and other attributes of structure or function. Databases are used to organize and archive data records. By relating the maps to cognitive functions and psychological models, brain mapping offers a prerequisite for the understanding of organizational principles of the human brain.

  9. Complex plastic changes in the neuropeptide Y system during ethanol intoxication and withdrawal in the rat brain

    DEFF Research Database (Denmark)

    Olling, J D; Ulrichsen, J; Christensen, D Z;

    2009-01-01

    Previous studies show that chronic ethanol treatment induces prominent changes in brain neuropeptide Y (NPY). The purpose of the present study was to explore ethanol effects at a deeper NPY-system level, measuring expression of NPY and its receptors (Y1, Y2, Y5) as well as NPY receptor binding and...... intoxication and in functional binding in the DG and NeoCx during intoxication and at 16 hr and in PirCx during intoxication and at 1 week. Thus this study shows that ethanol intoxication and withdrawal induce complex plastic changes in the NPY system, with decreased/increased gene expression or binding...

  10. Philosophy Thinking and Research on Complex Brain Network%复杂脑网络的哲学观思考与研究

    Institute of Scientific and Technical Information of China (English)

    张兰华; 许晓晨; 唐一源

    2011-01-01

    为了在复杂脑网络研究中取得新的进展,利用学科综合研究的方法引入哲学观思考,通过分析脑网络内在的哲学思想,论述哲学与脑网络之间的相互关系来说明脑网络的哲学含义,并对哲学含义下的脑网络应用进行阐述,最后以复杂脑网络的难题及潜在的哲学观思考印证哲学与复杂脑网络的相互联系,并提出进一步的思考.%Complex brain network researches make great progress by introducing the view of philosophy that brought by the relation and process of other subject developments. The study clarifies the inner philosophy thinking by the current situation of complex brain network, then discusses the mutual relations and explains the philosophy meaning of complex brain network and applications in it. At last, it confirms the relation between the philosophy and camplex brain network by the complex brain network puzzles and the potential philosophy thinking. Moreover, it puts forward the further research about the philosophy and the complex brain network problem.

  11. HIV-1 Tat Regulates Occludin and Aβ Transfer Receptor Expression in Brain Endothelial Cells via Rho/ROCK Signaling Pathway

    Science.gov (United States)

    Chen, Yanlan; Jiang, Wenlin; Wu, Xianghong; Ye, Biao; Zhou, Xiaoting

    2016-01-01

    HIV-1 transactivator protein (Tat) has been shown to play an important role in HIV-associated neurocognitive disorders. The aim of the present study was to evaluate the relationship between occludin and amyloid-beta (Aβ) transfer receptors in human cerebral microvascular endothelial cells (hCMEC/D3) in the context of HIV-1-related pathology. The protein expressions of occludin, receptor for advanced glycation end products (RAGE), and low-density lipoprotein receptor-related protein 1 (LRP1) in hCMEC/D3 cells were examined using western blotting and immunofluorescent staining. The mRNA levels of occludin, RAGE, and LRP1 were measured using quantitative real-time polymerase chain reaction. HIV-1 Tat at 1 µg/mL and the Rho inhibitor hydroxyfasudil (HF) at 30 µmol/L, with 24 h exposure, had no significant effect on hCMEC/D3 cell viability. Treatment with HIV-1 Tat protein decreased mRNA and protein levels of occludin and LRP1 and upregulated the expression of RAGE; however, these effects were attenuated by HF. These data suggest that the Rho/ROCK signaling pathway is involved in HIV-1 Tat-mediated changes in occludin, RAGE, and LRP1 in hCMEC/D3 cells. HF may have a beneficial influence by protecting the integrity of the blood-brain barrier and the expression of Aβ transfer receptors.

  12. Magnetic resonance imaging of the brain in chronic dialysis patients. Evaluation of high signal lesions in cerebral subcortical areas

    International Nuclear Information System (INIS)

    This study was aimed to evaluate the incidence of cerebral subcortical high signal lesions (SHS) on T2 weighted images of Magnetic Resonance Imaging in chronic dialysis patients. The incidence of SHS was investigated in three clinically different groups of patients (196 divided into 3 age groups (20-40, 41-60, 61-83 years old). SHS were graded according to size and number. The incidence and severity of SHS increased with advancing age in all groups of patients and were higher in hypertensive and dialysis patients. Patchy confluent SHS were not identified in any patient younger than 60 years old in normal subjects and hypertensive patients. They were present in 9% in patients 41 to 60 years old of dialysis patients. In patients over than 61 years old, patchy confluent SHS were present in 1% of normal subjects, 11% of hypertensive patients, and 30% of dialysis patients. Duration, methods of dialysis therapy or previous history of hypertension in dialysis patients did not affect the incidence of SHS. SHS were mainly located in the territory of anterior, middle carebral and lenticulostriate arteries. In one autopsy case of chronic dialysis patient with severe SHS on magnetic resonance images, microscopic finding at pathological examination showed dilated perivascular space and increased water content in white matter. The results demonstrate a high incidence of severe SHS in chronic dialysis patients, and suggest that the SHS in dialysis patients appear to represent increased water content in perivascular brain tissue. (author)

  13. Neuroprotective Effects of Rhynchophylline Against Ischemic Brain Injury via Regulation of the Akt/mTOR and TLRs Signaling Pathways

    Directory of Open Access Journals (Sweden)

    Houcai Huang

    2014-07-01

    Full Text Available Rhynchophylline (Rhy is an alkaloid isolated from Uncaria which has long been recommended for the treatment of central nervous diseases. In our study, the neuroprotective effect of Rhy was investigated in a stroke model, namely permanent middle cerebral artery occlusion (pMCAO. Rats were injected intraperitoneally once daily for four consecutive days before surgery and then received one more injection after surgery. The protein and mRNA levels of p-Akt, p-mTOR, apoptosis-related proteins (p-BAD and cleaved caspase-3, TLR2/4/9, NF-κB, MyD88, BDNF and claudin-5 were examined. Following pMCAO, Rhy treatment not only ameliorated neurological deficits, infarct volume and brain edema, but also increased claudin-5 and BDNF expressions (p < 0.05. Moreover, Rhy could activate PI3K/Akt/mTOR signaling while inhibiting TLRs/NF-κB pathway. Wortmannin, a selective PI3K inhibitor, could abolish the neuroprotective effect of Rhy and reverse the increment in p-Akt, p-mTOR and p-BAD levels. In conclusion, we hypothesize that Rhy protected against ischemic damage, probably via regulating the Akt/mTOR pathway.

  14. Neuroprotective effects of rhynchophylline against ischemic brain injury via regulation of the Akt/mTOR and TLRs signaling pathways.

    Science.gov (United States)

    Huang, Houcai; Zhong, Rongling; Xia, Zhi; Song, Jie; Feng, Liang

    2014-01-01

    Rhynchophylline (Rhy) is an alkaloid isolated from Uncaria which has long been recommended for the treatment of central nervous diseases. In our study, the neuroprotective effect of Rhy was investigated in a stroke model, namely permanent middle cerebral artery occlusion (pMCAO). Rats were injected intraperitoneally once daily for four consecutive days before surgery and then received one more injection after surgery. The protein and mRNA levels of p-Akt, p-mTOR, apoptosis-related proteins (p-BAD and cleaved caspase-3), TLR2/4/9, NF-κB, MyD88, BDNF and claudin-5 were examined. Following pMCAO, Rhy treatment not only ameliorated neurological deficits, infarct volume and brain edema, but also increased claudin-5 and BDNF expressions (p < 0.05). Moreover, Rhy could activate PI3K/Akt/mTOR signaling while inhibiting TLRs/NF-κB pathway. Wortmannin, a selective PI3K inhibitor, could abolish the neuroprotective effect of Rhy and reverse the increment in p-Akt, p-mTOR and p-BAD levels. In conclusion, we hypothesize that Rhy protected against ischemic damage, probably via regulating the Akt/mTOR pathway. PMID:25079660

  15. The Whole-Brain "Global" Signal from Resting State fMRI as a Potential Biomarker of Quantitative State Changes in Glucose Metabolism.

    Science.gov (United States)

    Thompson, Garth J; Riedl, Valentin; Grimmer, Timo; Drzezga, Alexander; Herman, Peter; Hyder, Fahmeed

    2016-07-01

    The evolution of functional magnetic resonance imaging to resting state (R-fMRI) allows measurement of changes in brain networks attributed to state changes, such as in neuropsychiatric diseases versus healthy controls. Since these networks are observed by comparing normalized R-fMRI signals, it is difficult to determine the metabolic basis of such group differences. To investigate the metabolic basis of R-fMRI network differences within a normal range, eyes open versus eyes closed in healthy human subjects was used. R-fMRI was recorded simultaneously with fluoro-deoxyglucose positron emission tomography (FDG-PET). Higher baseline FDG was observed in the eyes open state. Variance-based metrics calculated from R-fMRI did not match the baseline shift in FDG. Functional connectivity density (FCD)-based metrics showed a shift similar to the baseline shift of FDG, however, this was lost if R-fMRI "nuisance signals" were regressed before FCD calculation. Average correlation with the mean R-fMRI signal across the whole brain, generally regarded as a "nuisance signal," also showed a shift similar to the baseline of FDG. Thus, despite lacking a baseline itself, changes in whole-brain correlation may reflect changes in baseline brain metabolism. Conversely, variance-based metrics may remain similar between states due to inherent region-to-region differences overwhelming the differences between normal physiological states. As most previous studies have excluded the spatial means of R-fMRI metrics from their analysis, this work presents the first evidence of a potential R-fMRI biomarker for baseline shifts in quantifiable metabolism between brain states. PMID:27029438

  16. From PII signaling to metabolite sensing: a novel 2-oxoglutarate sensor that details PII-NAGK complex formation.

    Science.gov (United States)

    Lüddecke, Jan; Forchhammer, Karl

    2013-01-01

    The widespread PII signal transduction proteins are known for integrating signals of nitrogen and energy supply and regulating cellular behavior by interacting with a multitude of target proteins. The PII protein of the cyanobacterium Synechococcus elongatus forms complexes with the controlling enzyme of arginine synthesis, N-acetyl-L-glutamate kinase (NAGK) in a 2-oxoglutarate- and ATP/ADP-dependent manner. Fusing NAGK and PII proteins to either CFP or YFP yielded a FRET sensor that specifically responded to 2-oxoglutarate. The impact of the fluorescent tags on PII and NAGK was evaluated by enzyme assays, surface plasmon resonance spectroscopy and isothermal calorimetric experiments. The developed FRET sensor provides real-time data on PII - NAGK interaction and its modulation by the effector molecules ATP, ADP and 2-oxoglutarate in vitro. Additionally to its utility to monitor 2-oxoglutarate levels, the FRET assay provided novel insights into PII - NAGK complex formation: (i) It revealed the formation of an encounter-complex between PII and NAGK, which holds the proteins in proximity even in the presence of inhibitors of complex formation; (ii) It revealed that the PII T-loop residue Ser49 is neither essential for complex formation with NAGK nor for activation of the enzyme but necessary to form a stable complex and efficiently relieve NAGK from arginine inhibition; (iii) It showed that arginine stabilizes the NAGK hexamer and stimulates PII - NAGK interaction. PMID:24349456

  17. From PII signaling to metabolite sensing: a novel 2-oxoglutarate sensor that details PII-NAGK complex formation.

    Directory of Open Access Journals (Sweden)

    Jan Lüddecke

    Full Text Available The widespread PII signal transduction proteins are known for integrating signals of nitrogen and energy supply and regulating cellular behavior by interacting with a multitude of target proteins. The PII protein of the cyanobacterium Synechococcus elongatus forms complexes with the controlling enzyme of arginine synthesis, N-acetyl-L-glutamate kinase (NAGK in a 2-oxoglutarate- and ATP/ADP-dependent manner. Fusing NAGK and PII proteins to either CFP or YFP yielded a FRET sensor that specifically responded to 2-oxoglutarate. The impact of the fluorescent tags on PII and NAGK was evaluated by enzyme assays, surface plasmon resonance spectroscopy and isothermal calorimetric experiments. The developed FRET sensor provides real-time data on PII - NAGK interaction and its modulation by the effector molecules ATP, ADP and 2-oxoglutarate in vitro. Additionally to its utility to monitor 2-oxoglutarate levels, the FRET assay provided novel insights into PII - NAGK complex formation: (i It revealed the formation of an encounter-complex between PII and NAGK, which holds the proteins in proximity even in the presence of inhibitors of complex formation; (ii It revealed that the PII T-loop residue Ser49 is neither essential for complex formation with NAGK nor for activation of the enzyme but necessary to form a stable complex and efficiently relieve NAGK from arginine inhibition; (iii It showed that arginine stabilizes the NAGK hexamer and stimulates PII - NAGK interaction.

  18. Region-Specific Expression of Mitochondrial Complex I Genes during Murine Brain Development

    OpenAIRE

    Wirtz, Stefanie; Schuelke, Markus

    2011-01-01

    Mutations in the nuclear encoded subunits of mitochondrial complex I (NADH:ubiquinone oxidoreductase) may cause circumscribed cerebral lesions ranging from degeneration of the striatal and brainstem gray matter (Leigh syndrome) to leukodystrophy. We hypothesized that such pattern of regional pathology might be due to local differences in the dependence on complex I function. Using in situ hybridization we investigated the relative expression of 33 nuclear encoded complex I subunits in differe...

  19. Living longer living happier: My journey from clinical neurology to complexities of brain

    Directory of Open Access Journals (Sweden)

    Ashok Panagariya

    2011-01-01

    Full Text Available The present article is a treatise on the illuminating voyage of a Neurophysician along the fascinating horizons and frontiers of neurosciences. During the career as a clinical neurologist, some very interesting and intriguing cases and issues were dealt with and documented scientifically. The working of the brain and its operational architectonics came up for critical analysis, opening up new vistas in the appreciation and management of various neurological disorders. Issues regarding the working of the mind and the guidelines for health and happiness became apparent, and some very interesting generalizations with far-reaching consequences on the general well-being and health have been formulated and put forward for a healthy and happy future for mankind. A paradigm shift is warranted for a closer and better appreciation of neural dynamics at all levels of the brain, namely microscopic, mesoscopic and macroscopic levels!

  20. Naringin Improves Neuronal Insulin Signaling, Brain Mitochondrial Function, and Cognitive Function in High-Fat Diet-Induced Obese Mice.

    Science.gov (United States)

    Wang, Dongmei; Yan, Junqiang; Chen, Jing; Wu, Wenlan; Zhu, Xiaoying; Wang, Yong

    2015-10-01

    The epidemic and experimental studies have confirmed that the obesity induced by high-fat diet not only caused neuronal insulin resistance, but also induced brain mitochondrial dysfunction as well as learning impairment in mice. Naringin has been reported to posses biological functions which are beneficial to human cognitions, but its protective effects on HFD-induced cognitive deficits and underlying mechanisms have not been well characterized. In the present study Male C57BL/6 J mice were fed either a control or high-fat diet for 20 weeks and then randomized into four groups treated with their respective diets including control diet, control diet + naringin, high-fat diet (HFD), and high-fat diet + naringin (HFDN). The behavioral performance was assessed by using novel object recognition test and Morris water maze test. Hippocampal mitochondrial parameters were analyzed. Then the protein levels of insulin signaling pathway and the AMP-activated protein kinase (AMPK) in the hippocampus were detected by Western blot method. Our results showed that oral administration of naringin significantly improved the learning and memory abilities as evidenced by increasing recognition index by 52.5% in the novel object recognition test and inducing a 1.05-fold increase in the crossing-target number in the probe test, and ameliorated mitochondrial dysfunction in mice caused by HFD consumption. Moreover, naringin significantly enhanced insulin signaling pathway as indicated by a 34.5% increase in the expression levels of IRS-1, a 47.8% decrease in the p-IRS-1, a 1.43-fold increase in the p-Akt, and a 1.89-fold increase in the p-GSK-3β in the hippocampus of the HFDN mice versus HFD mice. Furthermore, the AMPK activity significantly increased in the naringin-treated (100 mg kg(-1) d(-1)) group. These findings suggest that an enhancement in insulin signaling and a decrease in mitochondrial dysfunction through the activation of AMPK may be one of the mechanisms that naringin

  1. The exon junction complex regulates the splicing of cell polarity gene dlg1 to control Wingless signaling in development

    Science.gov (United States)

    Liu, Min; Li, Yajuan; Liu, Aiguo; Li, Ruifeng; Su, Ying; Du, Juan; Li, Cheng; Zhu, Alan Jian

    2016-01-01

    Wingless (Wg)/Wnt signaling is conserved in all metazoan animals and plays critical roles in development. The Wg/Wnt morphogen reception is essential for signal activation, whose activity is mediated through the receptor complex and a scaffold protein Dishevelled (Dsh). We report here that the exon junction complex (EJC) activity is indispensable for Wg signaling by maintaining an appropriate level of Dsh protein for Wg ligand reception in Drosophila. Transcriptome analyses in Drosophila wing imaginal discs indicate that the EJC controls the splicing of the cell polarity gene discs large 1 (dlg1), whose coding protein directly interacts with Dsh. Genetic and biochemical experiments demonstrate that Dlg1 protein acts independently from its role in cell polarity to protect Dsh protein from lysosomal degradation. More importantly, human orthologous Dlg protein is sufficient to promote Dvl protein stabilization and Wnt signaling activity, thus revealing a conserved regulatory mechanism of Wg/Wnt signaling by Dlg and EJC. DOI: http://dx.doi.org/10.7554/eLife.17200.001 PMID:27536874

  2. Brain networks during free viewing of complex erotic movie: new insights on psychogenic erectile dysfunction.

    Science.gov (United States)

    Cera, Nicoletta; Di Pierro, Ezio Domenico; Ferretti, Antonio; Tartaro, Armando; Romani, Gian Luca; Perrucci, Mauro Gianni

    2014-01-01

    Psychogenic erectile dysfunction (ED) is defined as a male sexual dysfunction characterized by a persistent or recurrent inability to attain adequate penile erection due predominantly or exclusively to psychological or interpersonal factors. Previous fMRI studies were based on the common occurrence in the male sexual behaviour represented by the sexual arousal and penile erection related to viewing of erotic movies. However, there is no experimental evidence of altered brain networks in psychogenic ED patients (EDp). Some studies showed that fMRI activity collected during non sexual movie viewing can be analyzed in a reliable manner with independent component analysis (ICA) and that the resulting brain networks are consistent with previous resting state neuroimaging studies. In the present study, we investigated the modification of the brain networks in EDp compared to healthy controls (HC), using whole-brain fMRI during free viewing of an erotic video clip. Sixteen EDp and nineteen HC were recruited after RigiScan evaluation, psychiatric, and general medical evaluations. The performed ICA showed that visual network (VN), default-mode network (DMN), fronto-parietal network (FPN) and salience network (SN) were spatially consistent across EDp and HC. However, between-group differences in functional connectivity were observed in the DMN and in the SN. In the DMN, EDp showed decreased connectivity values in the inferior parietal lobes, posterior cingulate cortex and medial prefrontal cortex, whereas in the SN decreased and increased connectivity was observed in the right insula and in the anterior cingulate cortex respectively. The decreased levels of intrinsic functional connectivity principally involved the subsystem of DMN relevant for the self relevant mental simulation that concerns remembering of past experiences, thinking to the future and conceiving the viewpoint of the other's actions. Moreover, the between group differences in the SN nodes suggested a

  3. Brain networks during free viewing of complex erotic movie: new insights on psychogenic erectile dysfunction.

    Directory of Open Access Journals (Sweden)

    Nicoletta Cera

    Full Text Available Psychogenic erectile dysfunction (ED is defined as a male sexual dysfunction characterized by a persistent or recurrent inability to attain adequate penile erection due predominantly or exclusively to psychological or interpersonal factors. Previous fMRI studies were based on the common occurrence in the male sexual behaviour represented by the sexual arousal and penile erection related to viewing of erotic movies. However, there is no experimental evidence of altered brain networks in psychogenic ED patients (EDp. Some studies showed that fMRI activity collected during non sexual movie viewing can be analyzed in a reliable manner with independent component analysis (ICA and that the resulting brain networks are consistent with previous resting state neuroimaging studies. In the present study, we investigated the modification of the brain networks in EDp compared to healthy controls (HC, using whole-brain fMRI during free viewing of an erotic video clip. Sixteen EDp and nineteen HC were recruited after RigiScan evaluation, psychiatric, and general medical evaluations. The performed ICA showed that visual network (VN, default-mode network (DMN, fronto-parietal network (FPN and salience network (SN were spatially consistent across EDp and HC. However, between-group differences in functional connectivity were observed in the DMN and in the SN. In the DMN, EDp showed decreased connectivity values in the inferior parietal lobes, posterior cingulate cortex and medial prefrontal cortex, whereas in the SN decreased and increased connectivity was observed in the right insula and in the anterior cingulate cortex respectively. The decreased levels of intrinsic functional connectivity principally involved the subsystem of DMN relevant for the self relevant mental simulation that concerns remembering of past experiences, thinking to the future and conceiving the viewpoint of the other's actions. Moreover, the between group differences in the SN nodes

  4. Brain Networks during Free Viewing of Complex Erotic Movie: New Insights on Psychogenic Erectile Dysfunction

    OpenAIRE

    Cera, Nicoletta; Di Pierro, Ezio Domenico; Ferretti, Antonio; Tartaro, Armando; Romani, Gian Luca; Perrucci, Mauro Gianni

    2014-01-01

    Psychogenic erectile dysfunction (ED) is defined as a male sexual dysfunction characterized by a persistent or recurrent inability to attain adequate penile erection due predominantly or exclusively to psychological or interpersonal factors. Previous fMRI studies were based on the common occurrence in the male sexual behaviour represented by the sexual arousal and penile erection related to viewing of erotic movies. However, there is no experimental evidence of altered brain networks in psych...

  5. Personality and complex brain networks: The role of openness to experience in default network efficiency.

    Science.gov (United States)

    Beaty, Roger E; Kaufman, Scott Barry; Benedek, Mathias; Jung, Rex E; Kenett, Yoed N; Jauk, Emanuel; Neubauer, Aljoscha C; Silvia, Paul J

    2016-02-01

    The brain's default network (DN) has been a topic of considerable empirical interest. In fMRI research, DN activity is associated with spontaneous and self-generated cognition, such as mind-wandering, episodic memory retrieval, future thinking, mental simulation, theory of mind reasoning, and creative cognition. Despite large literatures on developmental and disease-related influences on the DN, surprisingly little is known about the factors that impact normal variation in DN functioning. Using structural equation modeling and graph theoretical analysis of resting-state fMRI data, we provide evidence that Openness to Experience-a normally distributed personality trait reflecting a tendency to engage in imaginative, creative, and abstract cognitive processes-underlies efficiency of information processing within the DN. Across two studies, Openness predicted the global efficiency of a functional network comprised of DN nodes and corresponding edges. In Study 2, Openness remained a robust predictor-even after controlling for intelligence, age, gender, and other personality variables-explaining 18% of the variance in DN functioning. These findings point to a biological basis of Openness to Experience, and suggest that normally distributed personality traits affect the intrinsic architecture of large-scale brain systems. Hum Brain Mapp 37:773-779, 2016. © 2015 Wiley Periodicals, Inc. PMID:26610181

  6. Deconstructing the ßcatenin destruction complex: mechanistic roles for the tumor suppressor APC in regulating Wnt signaling.

    Science.gov (United States)

    Roberts, David M; Pronobis, Mira I; Poulton, John S; Waldmann, Jon D; Stephenson, Elise M; Hanna, Shahnaz; Peifer, Mark

    2011-06-01

    Negatively regulating signaling by targeting key effectors for ubiquitination/destruction is essential for development and oncogenesis. The tumor suppressor adenomatous polyposis coli (APC), an essential negative regulator of Wnt signaling, provides a paradigm. APC mutations occur in most colon cancers. Acting in the "destruction complex" with Axin, glycogen synthase kinase 3, and casein kinase, APC targets ßcatenin (ßcat) for phosphorylation and recognition by an E3 ubiquitin-ligase. Despite 20 years of work, the internal workings of the destruction complex and APC's role remain largely mysterious. We use both Drosophila and colon cancer cells to test hypotheses for APC's mechanism of action. Our data are inconsistent with current models suggesting that high-affinity ßcat-binding sites on APC play key roles. Instead, they suggest that multiple ßcat-binding sites act additively to fine-tune signaling via cytoplasmic retention. We identify essential roles for two putative binding sites for new partners--20-amino-acid repeat 2 and conserved sequence B--in destruction complex action. Finally, we demonstrate that APC interacts with Axin by two different modes and provide evidence that conserved sequence B helps ensure release of APC from Axin, with disassembly critical in regulating ßcat levels. Using these data, we suggest a new model for destruction complex action in development, which also provides new insights into functions of truncated APC proteins in cancer. PMID:21471006

  7. Stable G protein-effector complexes in striatal neurons: mechanism of assembly and role in neurotransmitter signaling.

    Science.gov (United States)

    Xie, Keqiang; Masuho, Ikuo; Shih, Chien-Cheng; Cao, Yan; Sasaki, Keita; Lai, Chun Wan J; Han, Pyung-Lim; Ueda, Hiroshi; Dessauer, Carmen W; Ehrlich, Michelle E; Xu, Baoji; Willardson, Barry M; Martemyanov, Kirill A

    2015-01-01

    In the striatum, signaling via G protein-coupled neurotransmitter receptors is essential for motor control. Critical to this process is the effector enzyme adenylyl cyclase type 5 (AC5) that produces second messenger cAMP upon receptor-mediated activation by G protein Golf. However, the molecular organization of the Golf-AC5 signaling axis is not well understood. In this study, we report that in the striatum AC5 exists in a stable pre-coupled complex with subunits of Golf heterotrimer. We use genetic mouse models with disruption in individual components of the complex to reveal hierarchical order of interactions required for AC5-Golf stability. We further identify that the assembly of AC5-Golf complex is mediated by PhLP1 chaperone that plays central role in neurotransmitter receptor coupling to cAMP production motor learning. These findings provide evidence for the existence of stable G protein-effector signaling complexes and identify a new component essential for their assembly. PMID:26613416

  8. Insulin signaling, lifespan and stress resistance are modulated by metabotropic GABA receptors on insulin producing cells in the brain of Drosophila.

    Science.gov (United States)

    Enell, Lina E; Kapan, Neval; Söderberg, Jeannette A E; Kahsai, Lily; Nässel, Dick R

    2010-01-01

    Insulin-like peptides (ILPs) regulate growth, reproduction, metabolic homeostasis, life span and stress resistance in worms, flies and mammals. A set of insulin producing cells (IPCs) in the Drosophila brain that express three ILPs (DILP2, 3 and 5) have been the main focus of interest in hormonal DILP signaling. Little is, however, known about factors that regulate DILP production and release by these IPCs. Here we show that the IPCs express the metabotropic GABA(B) receptor (GBR), but not the ionotropic GABA(A) receptor subunit RDL. Diminishing the GBR expression on these cells by targeted RNA interference abbreviates life span, decreases metabolic stress resistance and alters carbohydrate and lipid metabolism at stress, but not growth in Drosophila. A direct effect of diminishing GBR on IPCs is an increase in DILP immunofluorescence in these cells, an effect that is accentuated at starvation. Knockdown of irk3, possibly part of a G protein-activated inwardly rectifying K(+) channel that may link to GBRs, phenocopies GBR knockdown in starvation experiments. Our experiments suggest that the GBR is involved in inhibitory control of DILP production and release in adult flies at metabolic stress and that this receptor mediates a GABA signal from brain interneurons that may convey nutritional signals. This is the first demonstration of a neurotransmitter that inhibits insulin signaling in its regulation of metabolism, stress and life span in an invertebrate brain. PMID:21209905

  9. Persistent activation of DNA damage signaling in response to complex mixtures of PAHs in air particulate matter

    International Nuclear Information System (INIS)

    Complex mixtures of polycyclic aromatic hydrocarbons (PAHs) are present in air particulate matter (PM) and have been associated with many adverse human health effects including cancer and respiratory disease. However, due to their complexity, the risk of exposure to mixtures is difficult to estimate. In the present study the effects of binary mixtures of benzo[a]pyrene (BP) and dibenzo[a,l]pyrene (DBP) and complex mixtures of PAHs in urban air PM extracts on DNA damage signaling was investigated. Applying a statistical model to the data we observed a more than additive response for binary mixtures of BP and DBP on activation of DNA damage signaling. Persistent activation of checkpoint kinase 1 (Chk1) was observed at significantly lower BP equivalent concentrations in air PM extracts than BP alone. Activation of DNA damage signaling was also more persistent in air PM fractions containing PAHs with more than four aromatic rings suggesting larger PAHs contribute a greater risk to human health. Altogether our data suggests that human health risk assessment based on additivity such as toxicity equivalency factor scales may significantly underestimate the risk of exposure to complex mixtures of PAHs. The data confirms our previous findings with PAH-contaminated soil (Niziolek-Kierecka et al., 2012) and suggests a possible role for Chk1 Ser317 phosphorylation as a biological marker for future analyses of complex mixtures of PAHs. -- Highlights: ► Benzo[a]pyrene (BP), dibenzo[a,l]pyrene (DBP) and air PM PAH extracts were compared. ► Binary mixture of BP and DBP induced a more than additive DNA damage response. ► Air PM PAH extracts were more potent than toxicity equivalency factor estimates. ► Larger PAHs (> 4 rings) contribute more to the genotoxicity of PAHs in air PM. ► Chk1 is a sensitive marker for persistent activation of DNA damage signaling from PAH mixtures.

  10. Molecular Evidence for Convergence and Parallelism in Evolution of Complex Brains of Cephalopod Molluscs: Insights from Visual Systems.

    Science.gov (United States)

    Yoshida, M A; Ogura, A; Ikeo, K; Shigeno, S; Moritaki, T; Winters, G C; Kohn, A B; Moroz, L L

    2015-12-01

    Coleoid cephalopods show remarkable evolutionary convergence with vertebrates in their neural organization, including (1) eyes and visual system with optic lobes, (2) specialized parts of the brain controlling learning and memory, such as vertical lobes, and (3) unique vasculature supporting such complexity of the central nervous system. We performed deep sequencing of eye transcriptomes of pygmy squids (Idiosepius paradoxus) and chambered nautiluses (Nautilus pompilius) to decipher the molecular basis of convergent evolution in cephalopods. RNA-seq was complemented by in situ hybridization to localize the expression of selected genes. We found three types of genomic innovations in the evolution of complex brains: (1) recruitment of novel genes into morphogenetic pathways, (2) recombination of various coding and regulatory regions of different genes, often called "evolutionary tinkering" or "co-option", and (3) duplication and divergence of genes. Massive recruitment of novel genes occurred in the evolution of the "camera" eye from nautilus' "pinhole" eye. We also showed that the type-2 co-option of transcription factors played important roles in the evolution of the lens and visual neurons. In summary, the cephalopod convergent morphological evolution of the camera eyes was driven by a mosaic of all types of gene recruitments. In addition, our analysis revealed unexpected variations of squids' opsins, retinochromes, and arrestins, providing more detailed information, valuable for further research on intra-ocular and extra-ocular photoreception of the cephalopods. PMID:26002349

  11. Analyzing the tradeoff between electrical complexity and accuracy in patient-specific computational models of deep brain stimulation

    Science.gov (United States)

    Howell, Bryan; McIntyre, Cameron C.

    2016-06-01

    Objective. Deep brain stimulation (DBS) is an adjunctive therapy that is effective in treating movement disorders and shows promise for treating psychiatric disorders. Computational models of DBS have begun to be utilized as tools to optimize the therapy. Despite advancements in the anatomical accuracy of these models, there is still uncertainty as to what level of electrical complexity is adequate for modeling the electric field in the brain and the subsequent neural response to the stimulation. Approach. We used magnetic resonance images to create an image-based computational model of subthalamic DBS. The complexity of the volume conductor model was increased by incrementally including heterogeneity, anisotropy, and dielectric dispersion in the electrical properties of the brain. We quantified changes in the load of the electrode, the electric potential distribution, and stimulation thresholds of descending corticofugal (DCF) axon models. Main results. Incorporation of heterogeneity altered the electric potentials and subsequent stimulation thresholds, but to a lesser degree than incorporation of anisotropy. Additionally, the results were sensitive to the choice of method for defining anisotropy, with stimulation thresholds of DCF axons changing by as much as 190%. Typical approaches for defining anisotropy underestimate the expected load of the stimulation electrode, which led to underestimation of the extent of stimulation. More accurate predictions of the electrode load were achieved with alternative approaches for defining anisotropy. The effects of dielectric dispersion were small compared to the effects of heterogeneity and anisotropy. Significance. The results of this study help delineate the level of detail that is required to accurately model electric fields generated by DBS electrodes.

  12. SNPs in the TGF-β signaling pathway are associated with increased risk of brain metastasis in patients with non-small-cell lung cancer.

    Directory of Open Access Journals (Sweden)

    Qianxia Li

    Full Text Available PURPOSE: Brain metastasis (BM from non-small cell lung cancer (NSCLC is relatively common, but identifying which patients will develop brain metastasis has been problematic. We hypothesized that genotype variants in the TGF-β signaling pathway could be a predictive biomarker of brain metastasis. PATIENTS AND METHODS: We genotyped 33 SNPs from 13 genes in the TGF-β signaling pathway and evaluated their associations with brain metastasis risk by using DNA from blood samples from 161 patients with NSCLC. Kaplan-Meier analysis was used to assess brain metastasis risk; Cox hazard analyses were used to evaluate the effects of various patient and disease characteristics on the risk of brain metastasis. RESULTS: The median age of the 116 men and 45 women in the study was 58 years; 62 (39% had stage IIIB or IV disease. Within 24 months after initial diagnosis of lung cancer, brain metastasis was found in 60 patients (37%. Of these 60 patients, 16 had presented with BM at diagnosis. Multivariate analysis showed the GG genotype of SMAD6: rs12913975 and TT genotype of INHBC: rs4760259 to be associated with a significantly higher risk of brain metastasis at 24 months follow-up (hazard ratio [HR] 2.540, 95% confidence interval [CI] 1.204-5.359, P = 0.014; and HR 1.885, 95% CI 1.086-3.273, P = 0.024, compared with the GA or CT/CC genotypes, respectively. When we analyzed combined subgroups, these rates showed higher for those having both the GG genotype of SMAD6: rs12913975 and the TT genotype of INHBC: rs4760259 (HR 2.353, 95% CI 1.390-3.985, P = 0.001. CONCLUSIONS: We found the GG genotype of SMAD6: rs12913975 and TT genotype of INHBC: rs4760259 to be associated with risk of brain metastasis in patients with NSCLC. This finding, if confirmed, can help to identify patients at high risk of brain metastasis.

  13. Investigating complex patterns of blocked intestinal artery blood pressure signals by empirical mode decomposition and linguistic analysis

    International Nuclear Information System (INIS)

    In this investigation, surgical operations of blocked intestinal artery have been conducted on pigs to simulate the condition of acute mesenteric arterial occlusion. The empirical mode decomposition method and the algorithm of linguistic analysis were applied to verify the blood pressure signals in simulated situation. We assumed that there was some information hidden in the high-frequency part of the blood pressure signal when an intestinal artery is blocked. The empirical mode decomposition method (EMD) has been applied to decompose the intrinsic mode functions (IMF) from a complex time series. But, the end effects and phenomenon of intermittence damage the consistence of each IMF. Thus, we proposed the complementary ensemble empirical mode decomposition method (CEEMD) to solve the problems of end effects and the phenomenon of intermittence. The main wave of blood pressure signals can be reconstructed by the main components, identified by Monte Carlo verification, and removed from the original signal to derive a riding wave. Furthermore, the concept of linguistic analysis was applied to design the blocking index to verify the pattern of riding wave of blood pressure using the measurements of dissimilarity. Blocking index works well to identify the situation in which the sampled time series of blood pressure signal was recorded. Here, these two totally different algorithms are successfully integrated and the existence of the existence of information hidden in high-frequency part of blood pressure signal has been proven

  14. Correction of complex nonlinear signal response from a pixel array detector

    DEFF Research Database (Denmark)

    Brandt van Driel, Tim; Herrmann, Sven; Carini, Gabriella; Nielsen, Martin Meedom; Lemke, Henrik Till

    2015-01-01

    The pulsed free-electron laser light sources represent a new challenge to photon area detectors due to the intrinsic spontaneous X-ray photon generation process that makes single-pulse detection necessary. Intensity fluctuations up to 100% between individual pulses lead to high linearity...... requirements in order to distinguish small signal changes. In real detectors, signal distortions as a function of the intensity distribution on the entire detector can occur. Here a robust method to correct this nonlinear response in an area detector is presented for the case of exposures to similar signals...

  15. Application of Entropy Measures on Intrinsic Mode Functions for the Automated Identification of Focal Electroencephalogram Signals

    OpenAIRE

    Rajeev Sharma; Ram Bilas Pachori; U. Rajendra Acharya

    2015-01-01

    The brain is a complex structure made up of interconnected neurons, and its electrical activities can be evaluated using electroencephalogram (EEG) signals. The characteristics of the brain area affected by partial epilepsy can be studied using focal and non-focal EEG signals. In this work, a method for the classification of focal and non-focal EEG signals is presented using entropy measures. These entropy measures can be useful in assessing the nonlinear interrelation and complexity of focal...

  16. Dynamic SPECT of the brain using a lipophilic technetium-99m complex, PnAO

    DEFF Research Database (Denmark)

    Holm, S; Andersen, A R; Vorstrup, S;

    1985-01-01

    The lipophilic 99mTc-labeled oxime propylene amine oxime (PnAO) should, according to recent reports behave like 133Xe in the human brain. This study compares SPECT images of the two tracers in six subjects: four stroke cases, one transitory ischemic attack case and one normal subject. Technetium-99...... cerebral blood flow followed by rapid washout. In the stroke cases, low flow areas were equally well visualized by both tracers. Two dissimilarities were seen in the initial pictures: PnAO visualized the cerebral veins and showed a lesser contrast of gray:white matter uptake. The results suggest that Pn...

  17. Multiple receptor complexes assembled for transmitting CLV3 signaling in Arabidopsis

    OpenAIRE

    Zhu, Yingfang; Wan, Yinglang; Lin, Jinxing

    2010-01-01

    In Arabidopsis, the feedback regulatory loop between CLAVATA3 (CLV3) signaling pathway and transcription factor, WUSCHEL (WUS) plays a significant role in shoot apical meristems (SAM) maintenance. Previously, CLV1/CLV2 heterodimers were supposed to perceive and transmit CLV3 signaling. Recent genetic analysis isolated a novel receptor kinase, CORYNE (CRN), which was found to be involved in the CLV3 pathway. Therefore, new hypothesis was put forward that CRN probably acts with CLV2 to transmit...

  18. Complex time dependence of the EPR signal of irradiated L-α-alanine

    International Nuclear Information System (INIS)

    Measurements of the EPR signal amplitude of γ-irradiated L-α-alanine with use of an adjacent reference sample have revealed variations in the signal intensity within hours and days after irradiation. The character of the time dependence of the amplitude varies with dose and the amplitude changes reach 1-1.5%. This observation favors the hypothesis that irradiated alanine contains several paramagnetic centers. Usefulness of adjacent reference samples in alanine dosimetry is also demonstrated. (Author)

  19. The role of enhanced cutaneous IL-1β signaling in a rat tibia fracture model of complex regional pain syndrome

    OpenAIRE

    Li, Wenwu; Sabsovich, Ilya; Guo, Tian-Zhi; Zhao, Rong; Kingery, Wade S.; Clark, J. David

    2009-01-01

    Tibia fracture in rats initiates a syndrome resembling the complex regional pain syndrome type I. Accumulating evidence indicates that IL-1β is involved in the modulation of nociceptive information and it acts as an intermediate inflammatory mediator via up-regulation of NGF. We hypothesized that IL-1β signaling might mediate the development of the CRPS-like changes after tibial fracture, either directly or by stimulating NGF expression. Rats underwent distal tibia fracture and casting for 4 ...

  20. The biological networks in studying cell signal transduction complexity: The examples of sperm capacitation and of endocannabinoid system

    OpenAIRE

    Nicola Bernabò; Barbara Barboni; Mauro Maccarrone

    2014-01-01

    Cellular signal transduction is a complex phenomenon, which plays a central role in cell surviving and adaptation. The great amount of molecular data to date present in literature, together with the adoption of high throughput technologies, on the one hand, made available to scientists an enormous quantity of information, on the other hand, failed to provide a parallel increase in the understanding of biological events. In this context, a new discipline arose, the systems biology, aimed to ma...

  1. Propofol-Induced Frontal Cortex Disconnection: A Study of Resting-State Networks, Total Brain Connectivity, and Mean BOLD Signal Oscillation Frequencies.

    Science.gov (United States)

    Guldenmund, Pieter; Gantner, Ithabi S; Baquero, Katherine; Das, Tushar; Demertzi, Athena; Boveroux, Pierre; Bonhomme, Vincent; Vanhaudenhuyse, Audrey; Bruno, Marie-Aurélie; Gosseries, Olivia; Noirhomme, Quentin; Kirsch, Muriëlle; Boly, Mélanie; Owen, Adrian M; Laureys, Steven; Gómez, Francisco; Soddu, Andrea

    2016-04-01

    Propofol is one of the most commonly used anesthetics in the world, but much remains unknown about the mechanisms by which it induces loss of consciousness. In this resting-state functional magnetic resonance imaging study, we examined qualitative and quantitative changes of resting-state networks (RSNs), total brain connectivity, and mean oscillation frequencies of the regional blood oxygenation level-dependent (BOLD) signal, associated with propofol-induced mild sedation and loss of responsiveness in healthy subjects. We found that detectability of RSNs diminished significantly with loss of responsiveness, and total brain connectivity decreased strongly in the frontal cortex, which was associated with increased mean oscillation frequencies of the BOLD signal. Our results suggest a pivotal role of the frontal cortex in propofol-induced loss of responsiveness. PMID:26650183

  2. Wogonin improves histological and functional outcomes, and reduces activation of TLR4/NF-κB signaling after experimental traumatic brain injury.

    Directory of Open Access Journals (Sweden)

    Chien-Cheng Chen

    Full Text Available BACKGROUND: Traumatic brain injury (TBI initiates a neuroinflammatory cascade that contributes to neuronal damage and behavioral impairment. This study was undertaken to investigate the effects of wogonin, a flavonoid with potent anti-inflammatory properties, on functional and histological outcomes, brain edema, and toll-like receptor 4 (TLR4- and nuclear factor kappa B (NF-κB-related signaling pathways in mice following TBI. METHODOLOGY/PRINCIPAL FINDINGS: Mice subjected to controlled cortical impact injury were injected with wogonin (20, 40, or 50 mg·kg(-1 or vehicle 10 min after injury. Behavioral studies, histology analysis, and measurement of blood-brain barrier (BBB permeability and brain water content were carried out to assess the effects of wogonin. Levels of TLR4/NF-κB-related inflammatory mediators were also examined. Treatment with 40 mg·kg(-1 wogonin significantly improved functional recovery and reduced contusion volumes up to post-injury day 28. Wogonin also significantly reduced neuronal death, BBB permeability, and brain edema beginning at day 1. These changes were associated with a marked reduction in leukocyte infiltration, microglial activation, TLR4 expression, NF-κB translocation to nucleus and its DNA binding activity, matrix metalloproteinase-9 activity, and expression of inflammatory mediators, including interleukin-1β, interleukin-6, macrophage inflammatory protein-2, and cyclooxygenase-2. CONCLUSIONS/SIGNIFICANCE: Our results show that post-injury wogonin treatment improved long-term functional and histological outcomes, reduced brain edema, and attenuated the TLR4/NF-κB-mediated inflammatory response in mouse TBI. The neuroprotective effects of wogonin may be related to modulation of the TLR4/NF-κB signaling pathway.

  3. A Signal-Processing-Based Approach to Time-Varying Graph Analysis for Dynamic Brain Network Identification

    OpenAIRE

    Ali Yener Mutlu; Edward Bernat; Selin Aviyente

    2012-01-01

    In recent years, there has been a growing need to analyze the functional connectivity of the human brain. Previous studies have focused on extracting static or time-independent functional networks to describe the long-term behavior of brain activity. However, a static network is generally not sufficient to represent the long term communication patterns of the brain and is considered as an unreliable snapshot of functional connectivity. In this paper, we propose a dynamic network summarization...

  4. The biological networks in studying cell signal transduction complexity: The examples of sperm capacitation and of endocannabinoid system

    Science.gov (United States)

    Bernabò, Nicola; Barboni, Barbara; Maccarrone, Mauro

    2014-01-01

    Cellular signal transduction is a complex phenomenon, which plays a central role in cell surviving and adaptation. The great amount of molecular data to date present in literature, together with the adoption of high throughput technologies, on the one hand, made available to scientists an enormous quantity of information, on the other hand, failed to provide a parallel increase in the understanding of biological events. In this context, a new discipline arose, the systems biology, aimed to manage the information with a computational modeling-based approach. In particular, the use of biological networks has allowed the making of huge progress in this field. Here we discuss two possible application of the use of biological networks to explore cell signaling: the study of the architecture of signaling systems that cooperate in determining the acquisition of a complex cellular function (as it is the case of the process of activation of spermatozoa) and the organization of a single specific signaling systems expressed by different cells in different tissues (i.e. the endocannabinoid system). In both the cases we have found that the networks follow a scale free and small world topology, likely due to the evolutionary advantage of robustness against random damages, fastness and specific of information processing, and easy navigability. PMID:25379139

  5. Alteration of Cortical Functional Connectivity as a Result of Traumatic Brain Injury Revealed by Graph Theory, ICA, and sLORETA Analyses of EEG Signals

    OpenAIRE

    Cao, C.; Slobounov, S.

    2009-01-01

    In this paper, a novel approach to examine the cortical functional connectivity using multichannel electroen-cephalographic (EEG) signals is proposed. First we utilized independent component analysis (ICA) to transform multichannel EEG recordings into independent processes and then applied source reconstruction algorithm [i.e., standardize low resolution brain electromagnetic (sLORETA)] to identify the cortical regions of interest (ROIs). Second, we performed a graph theory analysis of the bi...

  6. 99mTc complex conjugated to insulin: CNS radio-pharmaceuticals design based on principles of blood-brain barrier transport vector

    Institute of Scientific and Technical Information of China (English)

    LIU Fei; FAN Caiyun; ZHANG Jinming; WANG Wushang; LIU Boli

    2005-01-01

    Hydrophilic 99mTc-EC and nonlipophilic 99mTc- MAMA′-BA complexes, owing to the existing of intact blood-brain barrier (BBB) in vivo, cannot cross from blood to brain. Previous studies showed that insulin is selectively transported by receptor-mediated transcytosis through the brain capillary endothelial wall that makes up the BBB. In this paper, based on the characteristic of the insulin receptor enriched in brain capillary, the complexes of hydrophilic 99mTc-EC and nonlipophilic 99mTc-MAMA′-BA are conjugated to insulin respectively. After purification, the radiochemical purity of 99mTc-EC-insulin and 99mTc-MAMA′- BA-insulin was > 90% and the stability in vitro was good. Expectation for the special formulation can be internalized and endocytosed into the capillary membrane by the vector-mediated brain delivery system, and transported 99mTc-labeled conjugate through the BBB in vivo, thus enhancing brain uptake in mice. The biodistribution results of 99mTc-EC-insulin and 99mTc-MAMA′-BA-insulin in mice indicated that the brain uptake was higher than 99mTc-EC and 99mTc-MAMA′-BA to some extent. The ratios of brain uptake of 99mTc-EC-insulin to 99mTc-EC, 99mTc-MAMA′-BA-insulin to 99mTc-MAMA′-BA were 4―6 at 2 and 3 h post-injection respectively. In conclusion, the given results have illustrated a new way of brain uptake enhancing for nonlipophilic like complexes that have BBB delivery problems. It has a potential value for the ongoing development of 99mTc-labeled radiopharmaceuticals for CNS receptors imaging.

  7. Patterns of Cortical Oscillations Organize Neural Activity into Whole-Brain Functional Networks Evident in the fMRI BOLD Signal.

    Science.gov (United States)

    Whitman, Jennifer C; Ward, Lawrence M; Woodward, Todd S

    2013-01-01

    Recent findings from electrophysiology and multimodal neuroimaging have elucidated the relationship between patterns of cortical oscillations evident in EEG/MEG and the functional brain networks evident in the BOLD signal. Much of the existing literature emphasized how high-frequency cortical oscillations are thought to coordinate neural activity locally, while low-frequency oscillations play a role in coordinating activity between more distant brain regions. However, the assignment of different frequencies to different spatial scales is an oversimplification. A more informative approach is to explore the arrangements by which these low- and high-frequency oscillations work in concert, coordinating neural activity into whole-brain functional networks. When relating such networks to the BOLD signal, we must consider how the patterns of cortical oscillations change at the same speed as cognitive states, which often last less than a second. Consequently, the slower BOLD signal may often reflect the summed neural activity of several transient network configurations. This temporal mismatch can be circumvented if we use spatial maps to assess correspondence between oscillatory networks and BOLD networks. PMID:23504590

  8. Patterns of cortical oscillations organize neural activity into whole-brain functional networks evident in the fMRI BOLD signal

    Directory of Open Access Journals (Sweden)

    Jennifer C Whitman

    2013-03-01

    Full Text Available Recent findings from electrophysiology and multimodal neuroimaging have elucidated the relationship between patterns of cortical oscillations evident in EEG / MEG and the functional brain networks evident in the BOLD signal. Much of the existing literature emphasized how high-frequency cortical oscillations are thought to coordinate neural activity locally, while low-frequency oscillations play a role in coordinating activity between more distant brain regions. However, the assignment of different frequencies to different spatial scales is an oversimplification. A more informative approach is to explore the arrangements by which these low- and high-frequency oscillations work in concert, coordinating neural activity into whole-brain functional networks. When relating such networks to the BOLD signal, we must consider how the patterns of cortical oscillations change at the same speed as cognitive states, which often last less than a second. Consequently, the slower BOLD signal may often reflect the summed neural activity of several transient network configurations. This temporal mismatch can be circumvented if we use spatial maps to assess correspondence between oscillatory networks and BOLD networks.

  9. A System for True and False Memory Prediction Based on 2D and 3D Educational Contents and EEG Brain Signals

    Directory of Open Access Journals (Sweden)

    Saeed Bamatraf

    2016-01-01

    Full Text Available We studied the impact of 2D and 3D educational contents on learning and memory recall using electroencephalography (EEG brain signals. For this purpose, we adopted a classification approach that predicts true and false memories in case of both short term memory (STM and long term memory (LTM and helps to decide whether there is a difference between the impact of 2D and 3D educational contents. In this approach, EEG brain signals are converted into topomaps and then discriminative features are extracted from them and finally support vector machine (SVM which is employed to predict brain states. For data collection, half of sixty-eight healthy individuals watched the learning material in 2D format whereas the rest watched the same material in 3D format. After learning task, memory recall tasks were performed after 30 minutes (STM and two months (LTM, and EEG signals were recorded. In case of STM, 97.5% prediction accuracy was achieved for 3D and 96.6% for 2D and, in case of LTM, it was 100% for both 2D and 3D. The statistical analysis of the results suggested that for learning and memory recall both 2D and 3D materials do not have much difference in case of STM and LTM.

  10. A System for True and False Memory Prediction Based on 2D and 3D Educational Contents and EEG Brain Signals.

    Science.gov (United States)

    Bamatraf, Saeed; Hussain, Muhammad; Aboalsamh, Hatim; Qazi, Emad-Ul-Haq; Malik, Amir Saeed; Amin, Hafeez Ullah; Mathkour, Hassan; Muhammad, Ghulam; Imran, Hafiz Muhammad

    2016-01-01

    We studied the impact of 2D and 3D educational contents on learning and memory recall using electroencephalography (EEG) brain signals. For this purpose, we adopted a classification approach that predicts true and false memories in case of both short term memory (STM) and long term memory (LTM) and helps to decide whether there is a difference between the impact of 2D and 3D educational contents. In this approach, EEG brain signals are converted into topomaps and then discriminative features are extracted from them and finally support vector machine (SVM) which is employed to predict brain states. For data collection, half of sixty-eight healthy individuals watched the learning material in 2D format whereas the rest watched the same material in 3D format. After learning task, memory recall tasks were performed after 30 minutes (STM) and two months (LTM), and EEG signals were recorded. In case of STM, 97.5% prediction accuracy was achieved for 3D and 96.6% for 2D and, in case of LTM, it was 100% for both 2D and 3D. The statistical analysis of the results suggested that for learning and memory recall both 2D and 3D materials do not have much difference in case of STM and LTM. PMID:26819593

  11. Rapamycin Reduced Ischemic Brain Damage in Diabetic Animals Is Associated with Suppressions of mTOR and ERK1/2 Signaling

    Science.gov (United States)

    Liu, Ping; Yang, Xiao; Hei, Changchun; Meli, Yvonne; Niu, Jianguo; Sun, Tao; Li, P. Andy

    2016-01-01

    The objectives of the present study are to investigate the activation of mTOR and ERK1/2 signaling after cerebral ischemia in diabetic rats and to examine the neuroprotective effects of rapamycin. Ten minutes transient global cerebral ischemia was induced in straptozotocin-induced diabetic hyperglycemic rats and non-diabetic, euglycemic rats. Brain samples were harvested after 16 h of reperfusion. Rapamycin or vehicle was injected 1 month prior to the induction of ischemia. The results showed that diabetes increased ischemic neuronal cell death and associated with elevations of p-P70S6K and Ras/ERK1/2 and suppression of p-AMPKα. Rapamycin ameliorated diabetes-enhanced ischemic brain damage and suppressed phosphorylation of P70S6K and ERK1/2. It is concluded that diabetes activates mTOR and ERK1/2 signaling pathways in rats subjected to transient cerebral ischemia and inhibition of mTOR by rapamycin reduces ischemic brain damage and suppresses the mTOR and ERK1/2 signaling in diabetic settings. PMID:27489506

  12. Real-Time Frequency Estimation of Complex GMSK Signal of Green Communications Devices

    Institute of Scientific and Technical Information of China (English)

    Umar Suleiman Dauda; NikNoordini NikAbdMalik; Mazlina Esa; Kamaludin Mohd Yusof; Mohd Fairus Mohd Yusoff; Mohamed Rijal Hamid

    2016-01-01

    Abstract-Parameter estimation of signals of universal software radio peripheral (USRP) devices is crucial to solve the problem of phase offsets of received signals in distributed beamforming. For systems that will utilize the closed loop feedback algorithm where the receiver needs to send the received signal strength (RSS) values periodically to the beamforming node so as to take advantage of energy conservation, the frequency and phase of these signals should be estimated before smoothening by nonlinear filters. This article presents the estimation of the frequency offsets of a Gaussian minimum shift keying (GMSK) signal from N210 USRP devices in real time by using the Radix-2 fast Fourier transform (FFT) algorithm in GNURadio. For these green communications devices, most of the needed hardware parts have been software defined, thereby reducing the supposed energy consumption. The frequency offsets from reference carrier frequencies of 900 MHz and 2.4GHz are less than 3 kHz each before the estimation, but the average offsets are 45 Hz and 100 Hz after the estimation, respectively. The high offset value experienced with the 2.4GHz carrier was due to consistent interference from devices on that same frequency.

  13. Wing, tail, and vocal contributions to the complex acoustic signals of courting Calliope hummingbirds

    Directory of Open Access Journals (Sweden)

    Christopher James CLARK

    2011-04-01

    Full Text Available Multi-component signals contain multiple signal parts expressed in the same physical modality. One way to identify individual components is if they are produced by different physical mechanisms. Here, I studied the mechanisms generating acoustic signals in the courtship displays of the Calliope hummingbird Stellula calliope. Display dives consisted of three synchronized sound elements, a high-frequency tone (hft, a low frequency tone (lft, and atonal sound pulses (asp, which were then followed by a frequency-modulated fall. Manipulating any of the rectrices (tail-feathers of wild males impaired production of the lft and asp but not the hft or fall, which are apparently vocal. I tested the sound production capabilities of the rectrices in a wind tunnel. Single rectrices could generate the lft but not the asp, whereas multiple rectrices tested together produced sounds similar to the asp when they fluttered and collided with their neighbors percussively, representing a previously unknown mechanism of sound production. During the shuttle display, a trill is generated by the wings during pulses in which the wingbeat frequency is elevated to 95 Hz, 40% higher than the typical hovering wingbeat frequency. The Calliope hummingbird courtship displays include sounds produced by three independent mechanisms, and thus include a minimum of three acoustic signal components. These acoustic mechanisms have different constraints and thus potentially contain different messages. Producing multiple acoustic signals via multiple mechanisms may be a way to escape the constraints present in any single mechanism [Current Zoology 57 (2: 187–196, 2011].

  14. NADPH oxidase and lipid raft-associated redox signaling are required for PCB153-induced upregulation of cell adhesion molecules in human brain endothelial cells

    International Nuclear Information System (INIS)

    Exposure to persistent organic pollutants, such as polychlorinated biphenyls (PCBs), can lead to chronic inflammation and the development of vascular diseases. Because cell adhesion molecules (CAMs) of the cerebrovascular endothelium regulate infiltration of inflammatory cells into the brain, we have explored the molecular mechanisms by which ortho-substituted polychlorinated biphenyls (PCBs), such as PCB153, can upregulate CAMs in brain endothelial cells. Exposure to PCB153 increased expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1), as well as elevated adhesion of leukocytes to brain endothelial cells. These effects were impeded by inhibitors of EGFR, JAKs, or Src activity. In addition, pharmacological inhibition of NADPH oxidase or disruption of lipid rafts by cholesterol depleting agents blocked PCB153-induced phosphorylation of JAK and Src kinases and upregulation of CAMs. In contrast, silencing of caveolin-1 by siRNA interference did not affect upregulation of ICAM-1 and VCAM-1 in brain endothelial cells stimulated by PCB153. Results of the present study indicate that lipid raft-dependent NADPH oxidase/JAK/EGFR signaling mechanisms regulate the expression of CAMs in brain endothelial cells and adhesion of leukocytes to endothelial monolayers. Due to its role in leukocyte infiltration, induction of CAMs may contribute to PCB-induced cerebrovascular disorders and neurotoxic effects in the CNS.

  15. Focal cerebral vasculitis associated with circulating immune complexes and brain irradiation

    International Nuclear Information System (INIS)

    In this report we describe a patient with a benign glioma treated with surgery and radiation. After a period of stability he developed subacute bacterial endocarditis, and deteriorated neurologically. Computed tomographic scans did not show recurrent tumor. An angiogram showed vasculitis restricted to the previously irradiated area. Secondary to subacute bacterial endocarditis was the presence of high levels of circulating immune complexes. His neurological status was unchanged after antibiotics, but improved after treatment with dexamethasone. We interpret the clinical course as an immune-complex-mediated vasculitis superimposed on a subclinical radiation vasculitis. This case supports the hypothesis that immune mechanisms may be involved in delayed radiation injury to the nervous system

  16. Human-derived physiological heat shock protein 27 complex protects brain after focal cerebral ischemia in mice.

    Directory of Open Access Journals (Sweden)

    Shinichiro Teramoto

    Full Text Available Although challenging, neuroprotective therapies for ischemic stroke remain an interesting strategy for countering ischemic injury and suppressing brain tissue damage. Among potential neuroprotective molecules, heat shock protein 27 (HSP27 is a strong cell death suppressor. To assess the neuroprotective effects of HSP27 in a mouse model of transient middle cerebral artery occlusion, we purified a "physiological" HSP27 (hHSP27 from normal human lymphocytes. hHSP27 differed from recombinant HSP27 in that it formed dimeric, tetrameric, and multimeric complexes, was phosphorylated, and contained small amounts of αβ-crystallin and HSP20. Mice received intravenous injections of hHSP27 following focal cerebral ischemia. Infarct volume, neurological deficit scores, physiological parameters, and immunohistochemical analyses were evaluated 24 h after reperfusion. Intravenous injections of hHSP27 1 h after reperfusion significantly reduced infarct size and improved neurological deficits. Injected hHSP27 was localized in neurons on the ischemic side of the brain. hHSP27 suppressed neuronal cell death resulting from cytochrome c-mediated caspase activation, oxidative stress, and inflammatory responses. Recombinant HSP27 (rHSP27, which was artificially expressed and purified from Escherichia coli, and dephosphorylated hHSP27 did not have brain protective effects, suggesting that the phosphorylation of hHSP27 may be important for neuroprotection after ischemic insults. The present study suggests that hHSP27 with posttranslational modifications provided neuroprotection against ischemia/reperfusion injury and that the protection was mediated through the inhibition of apoptosis, oxidative stress, and inflammation. Intravenously injected human HSP27 should be explored for the treatment of acute ischemic strokes.

  17. CD163: a signal receptor scavenging haptoglobin-hemoglobin complexes from plasma

    DEFF Research Database (Denmark)

    Graversen, Jonas Heilskov; Madsen, Mette; Moestrup, Søren K

    2002-01-01

    endocytic receptor binding hemoglobin (Hb) in complex with the plasma protein haptoglobin (Hp). This specific receptor-ligand interaction leading to removal from plasma of the Hp-Hb complex-but not free Hp or Hb-now explains the depletion of circulating Hp in individuals with increased intravascular...... hemolysis. Besides having a detoxificating effect by removing Hb from plasma, the CD163-mediated endocytosis of the Hp-Hb complex may represent a major pathway for uptake of iron in the tissue macrophages. The novel functional linkage of CD163 and Hp, which both are induced during inflammation, also reveal...

  18. Stream computing for biomedical signal processing: A QRS complex detection case-study.

    Science.gov (United States)

    Murphy, B M; O'Driscoll, C; Boylan, G B; Lightbody, G; Marnane, W P

    2015-08-01

    Recent developments in "Big Data" have brought significant gains in the ability to process large amounts of data on commodity server hardware. Stream computing is a relatively new paradigm in this area, addressing the need to process data in real time with very low latency. While this approach has been developed for dealing with large scale data from the world of business, security and finance, there is a natural overlap with clinical needs for physiological signal processing. In this work we present a case study of streams processing applied to a typical physiological signal processing problem: QRS detection from ECG data. PMID:26737641

  19. The Relationship Between Relative Hydration Free Energies of 99mTcON2S2 Complexes and Their Brain Uptakes

    Institute of Scientific and Technical Information of China (English)

    SONG Wei; XUE Ying; CHEN Wei-zu; WANG Cun-xin; JIA Hong-mei; LIU Bo-li

    2003-01-01

    A thermodynamic integration dual-transform method was firstly applied to calculating the relative hydration free energies of 99mTcO-N2S2 complexes. The relationship between the brain uptakes(B.U.) of 99mTcO-N2S2 complexes with different substituted functional groups and their relative hydration free energies was investigated. The simulation results show that the experiment brain uptake(B.U.) data are strongly influenced by the relative hydration free energies of 99mTcO-N2S2 complexes, thus the simulations can provide the useful information for the medicine design of 99mTc brain imaging agents.

  20. Improved brain delivery of vincristine using dextran sulfate complex solid lipid nanoparticles: optimization and in vivo evaluation.

    Science.gov (United States)

    Aboutaleb, Ehsan; Atyabi, Fatemeh; Khoshayand, Mohammad Reza; Vatanara, Ali Reza; Ostad, Seyed Nasser; Kobarfard, Farzad; Dinarvand, Rassoul

    2014-07-01

    Vincristine (VC) sulfate, a freely water-soluble cytotoxic agent was incorporated into cetyl palmitate solid lipid nanoparticles (SLNs) with the aid of dextran sodium sulfate (DS), a poly anion, using a microemulsion method. The manufacturing process was optimized using response surface methodology (Box-Behnken design). SLNs were characterized for size, zeta potential, morphology, crystallinity, and release behavior. The drug encapsulation efficiency reached up to 93% and release study revealed sustained drug release. SLN formulation showed comparable cytotoxic effect in comparison to VC sulfate solution against the MDA-MB-231 cells. The in vivo studies following injection to rat revealed higher plasma and tissue concentrations and longer drug mean residence times compared to VC solution. Using cumarin-6 as a model drug, it was shown that drug delivery to the brain was enhanced close to five times using SLNs prepared in this study compared to free cumarin-6. It can be concluded that complexes of cetyl palmitate SLNs with DS could produce high VC-loaded SLNs suitable for delivery of anticancer drugs to brain tumors. PMID:23893939