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Sample records for brain electrical activity

  1. Order/disorder in brain electrical activity

    Science.gov (United States)

    Rosso, O. A.; Figliola, Y. A.

    2004-04-01

    The processing of information by the brain is reflected in dynamical changes of the electrical activity in time, frequency, and space. Therefore, the concomitant studies require methods capable of describing the quantitative variation of the signal in both time and frequency. Here we present a quantitative EEG (qEEG) analysis, based on the Orthogonal Discrete Wavelet Transform (ODWT), of generalized epileptic tonic-clonic EEG signals. Two quantifiers: the Relative Wavelet Energy (RWE) and the Normalized Total Wavelet Entropy (NTWS) have been used. The RWE gives information about the relative energy associated with the different frequency bands present in the EEG and their corresponding degree of importance. The NTWS is a measure of the order/disorder degree in the EEG signal. These two quantifiers were computing in EEG signals as provided by scalp electrodes of epileptic patients. We showed that the epileptic recruitment rhythm observed for generalized epileptic tonic-clonic seizures is accurately described by the RWE quantifier. In addition, a significant decrease in the NTWS was observed in the recruitment epoch, indicating a more rhythmic and ordered behavior in the brain electrical activity.

  2. Todd, Faraday, and the electrical basis of brain activity.

    Science.gov (United States)

    Reynolds, Edward H

    2004-09-01

    Robert Bentley Todd (1809-60) was the UK's first eminent neurologist and neuroscientist. An anatomist, physiologist, and clinical scientist with an interest in the nervous system, he was the first to confirm the electrical basis of brain activity in the 1840s. He was influenced by his contemporary, Michael Faraday at the Royal Institution, and by two colleagues at King's College, John Daniell and Charles Wheatstone, who were also working at the cutting edge of electrical science. Todd conceived of nervous polarity (force) generated in nervous centres and compared this with the polar force of voltaic electricity developed in the galvanic battery. He brilliantly foresaw each nerve vesicle (cell) and its related fibres (ie, neuron) as a distinct apparatus for the development and transmission of nervous polarity. Epilepsy was the result of periodic unnatural development of nervous force leading to the "disruptive discharge" described by Faraday. Faraday, who studied animal electricity in the Gymnotus (electric eel), and Todd saw nervous polarity as a higher form of interchangeable energy.

  3. Noninvasive method to assess the electrical brain activity from rats

    Directory of Open Access Journals (Sweden)

    Rosana Ferrari

    2013-10-01

    Full Text Available This research presents a noninvasive method for the acquisition of brain electrical signal in rat. Was used an electroencephalography (EEG system developed for bovine and adapted to rats. The bipolar electrode system (needle electrodes was glued on the surface of the head of the animal without surgical procedures and the other electrode was glued to the tail, as ground. The EEG activity was sampled at 120Hz for an hour. The accuracy and precision of the EEG measurement was performed using Fourier analysis and signal energy. For this, the digital signal was divided into sections successive of 3 seconds and was decomposed into four frequency bands: delta (0.3 to 4Hz, theta (4-8Hz, alpha (8-12Hz and beta (12-30Hz and energy (µV² of the series of time filtered were calculated. The method allowed the acquisition of non-invasive electrical brain signals in conscious rats and their frequency patterns were in agreement with previous studies that used surgical procedures to acquire EEG in rats. This system showed accuracy and precision and will allow further studies on behavior and to investigate the action of drugs on the central nervous system in rats without surgical procedures.

  4. Quantitative Brain Electrical Activity in the Initial Screening of Mild Traumatic Brain Injuries

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    Robert Chabot

    2012-12-01

    Full Text Available Introduction: The incidence of emergency department (ED visits for Traumatic Brain Injury (TBIin the United States exceeds 1,000,000 cases/year with the vast majority classified as mild (mTBI.Using existing computed tomography (CT decision rules for selecting patients to be referred for CT,such as the New Orleans Criteria (NOC, approximately 70% of those scanned are found to havea negative CT. This study investigates the use of quantified brain electrical activity to assess itspossible role in the initial screening of ED mTBI patients as compared to NOC.Methods: We studied 119 patients who reported to the ED with mTBI and received a CT. Using ahand-held electroencephalogram (EEG acquisition device, we collected data from frontal leadsto determine the likelihood of a positive CT. The brain electrical activity was processed off-line togenerate an index (TBI-Index, biomarker. This index was previously derived using an independentpopulation, and the value found to be sensitive for significant brain dysfunction in TBI patients. Wecompared this performance of the TBI-Index to the NOC for accuracy in prediction of positive CTfindings.Results: Both the brain electrical activity TBI-Index and the NOC had sensitivities, at 94.7% and92.1% respectively. The specificity of the TBI-Index was more than twice that of NOC, 49.4%and 23.5% respectively. The positive predictive value, negative predictive value and the positivelikelihood ratio were better with the TBI-Index. When either the TBI-Index or the NOC are positive(combining both indices the sensitivity to detect a positive CT increases to 97%.Conclusion: The hand-held EEG device with a limited frontal montage is applicable to the EDenvironment and its performance was superior to that obtained using the New Orleans criteria.This study suggests a possible role for an index of brain function based on EEG to aid in the acuteassessment of mTBI patients.

  5. Todd, Faraday and the electrical basis of brain activity.

    Science.gov (United States)

    Reynolds, Edward

    2007-10-01

    The origins of our understanding of brain electricity and electrical discharges in epilepsy can be traced to Robert Bentley Todd (1809-60). Todd was influenced by his contemporary in London, Michael Faraday (1791-1867), who in the 1830 s and 1840 s was laying the foundations of our modern understanding of electromagnetism. Todd's concept of nervous polarity, generated in nerve vesicles and transmitted in nerve fibres (neurons in later terminology), was confirmed a century later by the Nobel Prize-winning work of Hodgkin and Huxley, who demonstrated the ionic basis of neuro-transmission, involving the same ions which had had been discovered by Faraday's mentor, Sir Humphry Davy (1778-1829).

  6. Patterns recognition of electric brain activity using artificial neural networks

    Science.gov (United States)

    Musatov, V. Yu.; Pchelintseva, S. V.; Runnova, A. E.; Hramov, A. E.

    2017-04-01

    An approach for the recognition of various cognitive processes in the brain activity in the perception of ambiguous images. On the basis of developed theoretical background and the experimental data, we propose a new classification of oscillating patterns in the human EEG by using an artificial neural network approach. After learning of the artificial neural network reliably identified cube recognition processes, for example, left-handed or right-oriented Necker cube with different intensity of their edges, construct an artificial neural network based on Perceptron architecture and demonstrate its effectiveness in the pattern recognition of the EEG in the experimental.

  7. Patterns of Brain-Electrical Activity during Declarative Memory Performance in 10-Month-Old Infants

    Science.gov (United States)

    Morasch, Katherine C.; Bell, Martha Ann

    2009-01-01

    This study of infant declarative memory concurrently examined brain-electrical activity and deferred imitation performance in 10-month-old infants. Continuous electroencephalogram (EEG) measures were collected throughout the activity-matched baseline, encoding (modeling) and retrieval (delayed test) phases of a within-subjects deferred imitation…

  8. Dynamic Variation in Pleasure in Children Predicts Nonlinear Change in Lateral Frontal Brain Electrical Activity

    Science.gov (United States)

    Light, Sharee N.; Coan, James A.; Frye, Corrina; Goldsmith, H. Hill; Davidson, Richard J.

    2009-01-01

    Individual variation in the experience and expression of pleasure may relate to differential patterns of lateral frontal activity. Brain electrical measures have been used to study the asymmetric involvement of lateral frontal cortex in positive emotion, but the excellent time resolution of these measures has not been used to capture…

  9. Timing of intervention affects brain electrical activity in children exposed to severe psychosocial neglect.

    Directory of Open Access Journals (Sweden)

    Ross E Vanderwert

    Full Text Available BACKGROUND: Early psychosocial deprivation has profound effects on brain activity in the young child. Previous reports have shown increased power in slow frequencies of the electroencephalogram (EEG, primarily in the theta band, and decreased power in higher alpha and beta band frequencies in infants and children who have experienced institutional care. METHODOLOGY/PRINCIPAL FINDINGS: We assessed the consequences of removing infants from institutions and placing them into a foster care intervention on brain electrical activity when children were 8 years of age. We found the intervention was successful for increasing high frequency EEG alpha power, with effects being most pronounced for children placed into foster care before 24 months of age. CONCLUSIONS/SIGNIFICANCE: The dependence on age of placement for the effects observed on high frequency EEG alpha power suggests a sensitive period after which brain activity in the face of severe psychosocial deprivation is less amenable to recovery.

  10. Brain electrical activities of dancers and fast ball sports athletes are different.

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    Ermutlu, Numan; Yücesir, Ilker; Eskikurt, Gökçer; Temel, Tan; İşoğlu-Alkaç, Ümmühan

    2015-04-01

    Exercise training has been shown not only to influence physical fitness positively but also cognition in healthy and impaired populations. However, some particular exercise types, even though comparable based on physical efforts, have distinct cognitive and sensorimotor features. In this study, the effects of different types of exercise, such as fast ball sports and dance training, on brain electrical activity were investigated. Electroencephalography (EEG) scans were recorded in professional dancer, professional fast ball sports athlete (FBSA) and healthy control volunteer groups consisting of twelve subjects each. In FBSA, power of delta and theta frequency activities of EEG was significantly higher than those of the dancers and the controls. Conversely, dancers had significantly higher amplitudes in alpha and beta bands compared to FBSA and significantly higher amplitudes in the alpha band in comparison with controls. The results suggest that cognitive features of physical training can be reflected in resting brain electrical oscillations. The differences in resting brain electrical oscillations between the dancers and the FBSA can be the result of innate network differences determining the talents and/or plastic changes induced by physical training.

  11. Spatio-temporal analysis of brain electrical activity in epilepsy based on cellular nonlinear networks

    Science.gov (United States)

    Gollas, Frank; Tetzlaff, Ronald

    2009-05-01

    Epilepsy is the most common chronic disorder of the nervous system. Generally, epileptic seizures appear without foregoing sign or warning. The problem of detecting a possible pre-seizure state in epilepsy from EEG signals has been addressed by many authors over the past decades. Different approaches of time series analysis of brain electrical activity already are providing valuable insights into the underlying complex dynamics. But the main goal the identification of an impending epileptic seizure with a sufficient specificity and reliability, has not been achieved up to now. An algorithm for a reliable, automated prediction of epileptic seizures would enable the realization of implantable seizure warning devices, which could provide valuable information to the patient and time/event specific drug delivery or possibly a direct electrical nerve stimulation. Cellular Nonlinear Networks (CNN) are promising candidates for future seizure warning devices. CNN are characterized by local couplings of comparatively simple dynamical systems. With this property these networks are well suited to be realized as highly parallel, analog computer chips. Today available CNN hardware realizations exhibit a processing speed in the range of TeraOps combined with low power consumption. In this contribution new algorithms based on the spatio-temporal dynamics of CNN are considered in order to analyze intracranial EEG signals and thus taking into account mutual dependencies between neighboring regions of the brain. In an identification procedure Reaction-Diffusion CNN (RD-CNN) are determined for short segments of brain electrical activity, by means of a supervised parameter optimization. RD-CNN are deduced from Reaction-Diffusion Systems, which usually are applied to investigate complex phenomena like nonlinear wave propagation or pattern formation. The Local Activity Theory provides a necessary condition for emergent behavior in RD-CNN. In comparison linear spatio

  12. Increased determinism in brain electrical activity occurs in association with multiple sclerosis.

    Science.gov (United States)

    Carrubba, Simona; Minagar, Alireza; Chesson, Andrew L; Frilot, Clifton; Marino, Andrew A

    2012-04-01

    Increased determinism (decreased complexity) of brain electrical activity has been associated with some brain diseases. Our objective was to determine whether a similar association occurred for multiple sclerosis (MS). Ten subjects with a relapsing-remitting course of MS who were in remission were studied; the controls were age- and gender-matched clinically normal subjects. Recurrence plots were calculated using representative electroencephalogram (EEG) epochs (1-7 seconds) from six derivations; the plots were quantified using the nonlinear variables percent recurrence (%R) and percent determinism (%D). The results were averaged over all derivations for each participant, and the means were compared between the groups. As a linear control procedure the groups were also compared using spectral analysis. The mean±SD of %R for the MS subjects was 6·6±1·3%, compared with 5·1±1·3% in the normal group (P = 0·017), indicating that brain activity in the subjects with MS was less complex, as hypothesized. The groups were not distinguishable using %D or spectral analysis. Taken together with our earlier report that %R could be used to discriminate between MS and normal subjects based on the ability to exhibit evoked potentials, the evidence suggests that complexity analysis of the EEG has potential for development as a diagnostic test for MS.

  13. Infants of Depressed and Nondepressed Mothers Exhibit Differences in Frontal Brain Electrical Activity during the Expression of Negative Emotions.

    Science.gov (United States)

    Dawson, Geraldine; And Others

    1997-01-01

    Examined electrical brain activity during negative and positive emotion expression in infants of depressed and nondepressed mothers. Found that, compared with infants of nondepressed mothers, infants of depressed mothers exhibited increased EEG activation in the frontal but not parietal region when expressing negative emotions. There were no…

  14. Brain electric activity during the preattentive perception of speech sounds in tonal languages

    Directory of Open Access Journals (Sweden)

    Naiphinich Kotchabhakdi

    2004-05-01

    Full Text Available The present study was intended to make electrophysiological investigations into the preattentive perception of native and non-native speech sounds. We recorded the mismatch negativity, elicited by single syllable change of both native and non-native speech-sound contrasts in tonal languages. EEGs were recorded and low-resolution brain electromagnetic tomography (LORETA was utilized to explore the neural electrical activity. Our results suggested that the left hemisphere was predominant in the perception of native speech sounds, whereas the non-native speech sound was perceived predominantly by the right hemisphere, which may be explained by the specialization in processing the prosodic and emotional components of speech formed in this hemisphere.

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

    Science.gov (United States)

    Fröhlich, Flavio

    2014-03-01

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

  16. Language selection in bilinguals: a spatio-temporal analysis of electric brain activity.

    Science.gov (United States)

    Khateb, Asaid; Abutalebi, Jubin; Michel, Christoph M; Pegna, Alan J; Lee-Jahnke, Hannelore; Annoni, Jean-Marie

    2007-09-01

    Language selection refers to the cognitive mechanism that allows bilinguals to communicate in one language or the other and to switch between languages depending on the listener. Previous studies suggested that various brain areas might be involved in this process. However, the question remains whether language selection is achieved through a language-specific mechanism or through a general cognitive control process. To address this question, we compared event-related potentials (ERPs) induced by language selection and task selection processes during image naming. ERPs were collected from bilingual subjects while tested in two different contexts: a monolingual task selection context (TSc) where a post-stimulus cue instructed subjects either to name the image or generate a corresponding verb in their first language (L1), and a bilingual language selection context (LSc) where the cue indicated to name the image either in the first or the second language. By comparing the ERPs induced by the same L1 naming as a function of context, we assumed that if the selection processes varied across contexts, then electric brain responses should differ rapidly after the cue presentation. Our analysis indicated that the first ERP differences accounting for the diverging processes involved appeared between approximately 220 and 300 ms after the cue. The estimation by source localisation of brain regions accounting for these differences pointed to an increased activation during LSc in the left middle frontal-precentral gyri, supramarginal and angular gyri. Our results suggest that language selection is achieved through a neural network involving areas implicated in both general cognitive processes and language processing.

  17. Effects of auditory stimuli on electrical activity in the brain during cycle ergometry.

    Science.gov (United States)

    Bigliassi, Marcelo; Karageorghis, Costas I; Wright, Michael J; Orgs, Guido; Nowicky, Alexander V

    2017-08-01

    The present study sought to further understanding of the brain mechanisms that underlie the effects of music on perceptual, affective, and visceral responses during whole-body modes of exercise. Eighteen participants were administered light-to-moderate intensity bouts of cycle ergometer exercise. Each exercise bout was of 12-min duration (warm-up [3min], exercise [6min], and warm-down [3min]). Portable techniques were used to monitor the electrical activity in the brain, heart, and muscle during the administration of three conditions: music, audiobook, and control. Conditions were randomized and counterbalanced to prevent any influence of systematic order on the dependent variables. Oscillatory potentials at the Cz electrode site were used to further understanding of time-frequency changes influenced by voluntary control of movements. Spectral coherence analysis between Cz and frontal, frontal-central, central, central-parietal, and parietal electrode sites was also calculated. Perceptual and affective measures were taken at five timepoints during the exercise bout. Results indicated that music reallocated participants' attentional focus toward auditory pathways and reduced perceived exertion. The music also inhibited alpha resynchronization at the Cz electrode site and reduced the spectral coherence values at Cz-C4 and Cz-Fz. The reduced focal awareness induced by music led to a more autonomous control of cycle movements performed at light-to-moderate-intensities. Processing of interoceptive sensory cues appears to upmodulate fatigue-related sensations, increase the connectivity in the frontal and central regions of the brain, and is associated with neural resynchronization to sustain the imposed exercise intensity. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  18. Clinical usefulness of brain-computer interface-controlled functional electrical stimulation for improving brain activity in children with spastic cerebral palsy: a pilot randomized controlled trial

    OpenAIRE

    Kim, Tae-Woo; Lee, Byoung-Hee

    2016-01-01

    [Purpose] Evaluating the effect of brain-computer interface (BCI)-based functional electrical stimulation (FES) training on brain activity in children with spastic cerebral palsy (CP) was the aim of this study. [Subjects and Methods] Subjects were randomized into a BCI-FES group (n=9) and a functional electrical stimulation (FES) control group (n=9). Subjects in the BCI-FES group received wrist and hand extension training with FES for 30 minutes per day, 5 times per week for 6 weeks under the...

  19. Effect of diet with omega-3 in basal brain electrical activity and during status epilepticus in rats.

    Science.gov (United States)

    Pessoa, Daniella Tavares; da Silva, Eva Luana Almeida; Costa, Edbhergue Ventura Lola; Nogueira, Romildo Albuquerque

    2017-11-01

    Western diets are high in saturated fat and low in omega-3. Certain animals cannot produce omega-3 from their own lipids, making it necessary for it to be acquired from the diet. However, omega-3s are important components of the plasma membrane, and altering their proportions can promote physical and chemical alterations in the membranes, which may modify neuronal excitability. These alterations occur in healthy individuals, as well as in patients with epilepsy who are more sensitive to changes in brain electrical activity. This study evaluated the effect of a diet supplemented with omega-3 on the basal brain electrical activity both before and during status epilepticus in rats. To evaluate the brain electrical activity, we recorded electrocorticograms (ECoG) of animals both with and without omega-3 supplementation before and during status epilepticus induced by pilocarpine. Calculation of the average brain wave power by a power spectrum revealed that omega-3 supplementation reduced the average power of the delta wave by 20% and increased the average power of the beta wave by 45%. These effects were exacerbated when status epilepticus was induced in the animals supplemented with omega-3. The animals with and without omega-3 supplementation exhibited increases in basal brain electrical activities during status epilepticus. The two groups showed hyperactivity, but no significant difference between them was noted. Even though the brain activity levels observed during status epilepticus were similar between the two groups, neuron damage to the animals supplemented with omega-3 was more slight, revealing the neuroprotective effect of the omega-3. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. [The changes in the brain's electrical activity in children with cerebral palsy during the complex rehabilitation].

    Science.gov (United States)

    Ukhanova, T A; Gorbunov, F E; Dement'eva, E V; Volkova, E A; Novikova, E E

    2012-01-01

    One hundred and five children, aged from 3 to 7 years, with the diagnosis "spastic diplegia cerebral palsy" were treated. Patients were stratified into three groups: group I (n=36) received three courses of microcurrent therapy (MENS) in addition to standard treatment; group II (n=38) received three courses of MENS in the combination with two treatment courses with the nootropic drug cortexin; children of group III (n=31) received standard therapy using massage and gymnastics. MENS was carried out in courses, including 15 sessions each, using the apparatus "MEKS". Cortexin was introduced intramuscular in dosage 10 mg, the treatment course consisted of 10 injections. To the end of the rehabilitation program, positive changes were found: 50% patients of group I, 66% patients of group II and 16% patients of group III could perform complex instructions and acquired skills in modeling and recognition of geometric forms. Positive changes in the brain's electrical activity were found in 75% of children in group I, in 82% of children in group II and in 64% of children in group III.

  1. Localization of Brain Electrical Activity Sources and Hemodynamic Activity Foci during Motor Imagery

    Czech Academy of Sciences Publication Activity Database

    Frolov, A. A.; Húsek, Dušan; Mokienko, O.; Bobrov, P.; Chernikova, L.; Konovalov, R.

    2014-01-01

    Roč. 40, č. 3 (2014), s. 273-283 ISSN 0362-1197 Grant - others:GA MŠk(CZ) ED1.1.00/02.0070; GA MŠk(CZ) EE.2.3.20.0073 Program:ED Institutional support: RVO:67985807 Keywords : brain computer interface * independent component analysis * EEG pattern classification * motor imagery * inverse EEG problem Subject RIV: IN - Informatics, Computer Science

  2. Effects of brain-computer interface-based functional electrical stimulation on brain activation in stroke patients: a pilot randomized controlled trial.

    Science.gov (United States)

    Chung, EunJung; Kim, Jung-Hee; Park, Dae-Sung; Lee, Byoung-Hee

    2015-03-01

    [Purpose] This study sought to determine the effects of brain-computer interface-based functional electrical stimulation (BCI-FES) on brain activation in patients with stroke. [Subjects] The subjects were randomized to in a BCI-FES group (n=5) and a functional electrical stimulation (FES) group (n=5). [Methods] Patients in the BCI-FES group received ankle dorsiflexion training with FES for 30 minutes per day, 5 times under the brain-computer interface-based program. The FES group received ankle dorsiflexion training with FES for the same amount of time. [Results] The BCI-FES group demonstrated significant differences in the frontopolar regions 1 and 2 attention indexes, and frontopolar 1 activation index. The FES group demonstrated no significant differences. There were significant differences in the frontopolar 1 region activation index between the two groups after the interventions. [Conclusion] The results of this study suggest that BCI-FES training may be more effective in stimulating brain activation than only FES training in patients recovering from stroke.

  3. Automated analysis of seizure semiology and brain electrical activity in presurgery evaluation of epilepsy: A focused survey.

    Science.gov (United States)

    Ahmedt-Aristizabal, David; Fookes, Clinton; Dionisio, Sasha; Nguyen, Kien; Cunha, João Paulo S; Sridharan, Sridha

    2017-11-01

    Epilepsy being one of the most prevalent neurological disorders, affecting approximately 50 million people worldwide, and with almost 30-40% of patients experiencing partial epilepsy being nonresponsive to medication, epilepsy surgery is widely accepted as an effective therapeutic option. Presurgical evaluation has advanced significantly using noninvasive techniques based on video monitoring, neuroimaging, and electrophysiological and neuropsychological tests; however, certain clinical settings call for invasive intracranial recordings such as stereoelectroencephalography (SEEG), aiming to accurately map the eloquent brain networks involved during a seizure. Most of the current presurgical evaluation procedures focus on semiautomatic techniques, where surgery diagnosis relies immensely on neurologists' experience and their time-consuming subjective interpretation of semiology or the manifestations of epilepsy and their correlation with the brain's electrical activity. Because surgery misdiagnosis reaches a rate of 30%, and more than one-third of all epilepsies are poorly understood, there is an evident keen interest in improving diagnostic precision using computer-based methodologies that in the past few years have shown near-human performance. Among them, deep learning has excelled in many biological and medical applications, but has advanced insufficiently in epilepsy evaluation and automated understanding of neural bases of semiology. In this paper, we systematically review the automatic applications in epilepsy for human motion analysis, brain electrical activity, and the anatomoelectroclinical correlation to attribute anatomical localization of the epileptogenic network to distinctive epilepsy patterns. Notably, recent advances in deep learning techniques will be investigated in the contexts of epilepsy to address the challenges exhibited by traditional machine learning techniques. Finally, we discuss and propose future research on epilepsy surgery assessment

  4. Significance probability mapping: an aid in the topographic analysis of brain electrical activity.

    Science.gov (United States)

    Duffy, F H; Bartels, P H; Burchfiel, J L

    1981-05-01

    We illustrate the application of significance probability mapping (SPM) to the analysis of topographic maps of spectral analyzed EEG and visual evoked potential (VEP) activity from patients with brain tumors, boys with dyslexia, and control subjects. When the VEP topographic plots of tumor patients were displayed as number of standard deviations from a reference mean, more subjects were correctly identified than by inspection of the underlying raw data. When topographic plots of EEG alpha activity obtained while listening to speech or music were compared by t statistic to plots of resting alpha activity, regions of cortex presumably activated by speech or music were delineated. DIfferent regions were defined in dyslexic boys and controls. We propose that SPM will prove valuable in the regional localization of normal and abnormal functions in other clinical situations.

  5. Clinical usefulness of brain-computer interface-controlled functional electrical stimulation for improving brain activity in children with spastic cerebral palsy: a pilot randomized controlled trial.

    Science.gov (United States)

    Kim, Tae-Woo; Lee, Byoung-Hee

    2016-09-01

    [Purpose] Evaluating the effect of brain-computer interface (BCI)-based functional electrical stimulation (FES) training on brain activity in children with spastic cerebral palsy (CP) was the aim of this study. [Subjects and Methods] Subjects were randomized into a BCI-FES group (n=9) and a functional electrical stimulation (FES) control group (n=9). Subjects in the BCI-FES group received wrist and hand extension training with FES for 30 minutes per day, 5 times per week for 6 weeks under the BCI-based program. The FES group received wrist and hand extension training with FES for the same amount of time. Sensorimotor rhythms (SMR) and middle beta waves (M-beta) were measured in frontopolar regions 1 and 2 (Fp1, Fp2) to determine the effects of BCI-FES training. [Results] Significant improvements in the SMR and M-beta of Fp1 and Fp2 were seen in the BCI-FES group. In contrast, significant improvement was only seen in the SMR and M-beta of Fp2 in the control group. [Conclusion] The results of the present study suggest that BCI-controlled FES training may be helpful in improving brain activity in patients with cerebral palsy and may be applied as effectively as traditional FES training.

  6. Clinical usefulness of brain-computer interface-controlled functional electrical stimulation for improving brain activity in children with spastic cerebral palsy: a pilot randomized controlled trial

    Science.gov (United States)

    Kim, Tae-Woo; Lee, Byoung-Hee

    2016-01-01

    [Purpose] Evaluating the effect of brain-computer interface (BCI)-based functional electrical stimulation (FES) training on brain activity in children with spastic cerebral palsy (CP) was the aim of this study. [Subjects and Methods] Subjects were randomized into a BCI-FES group (n=9) and a functional electrical stimulation (FES) control group (n=9). Subjects in the BCI-FES group received wrist and hand extension training with FES for 30 minutes per day, 5 times per week for 6 weeks under the BCI-based program. The FES group received wrist and hand extension training with FES for the same amount of time. Sensorimotor rhythms (SMR) and middle beta waves (M-beta) were measured in frontopolar regions 1 and 2 (Fp1, Fp2) to determine the effects of BCI-FES training. [Results] Significant improvements in the SMR and M-beta of Fp1 and Fp2 were seen in the BCI-FES group. In contrast, significant improvement was only seen in the SMR and M-beta of Fp2 in the control group. [Conclusion] The results of the present study suggest that BCI-controlled FES training may be helpful in improving brain activity in patients with cerebral palsy and may be applied as effectively as traditional FES training. PMID:27799677

  7. Evidence of self-organization in brain electrical activity using wavelet-based informational tools

    Science.gov (United States)

    Rosso, O. A.; Martin, M. T.; Plastino, A.

    2005-03-01

    In the present work, we show that appropriate information-theory tools based on the wavelet transform (relative wavelet energy; normalized total wavelet entropy, H; generalized wavelet complexity, CW), when applied to tonic-clonic epileptic EEG data, provide one with valuable insights into the dynamics of neural activity. Twenty tonic-clonic secondary generalized epileptic records pertaining to eight patients have been analyzed. If the electromyographic activity is excluded the difference between the ictal and pre-ictal mean entropic values (ΔH=-) is negative in 95% of the cases (p-) is positive in 85% of the cases (p=0.0002). Thus during the seizure entropy diminishes while complexity grows. This is construed as evidence supporting the conjecture that an epileptic focus in this kind of seizures triggers a self-organized brain state characterized by both order and maximal complexity.

  8. Regional brain electrical activity in posttraumatic stress disorder after motor vehicle accident.

    Science.gov (United States)

    Rabe, Sirko; Beauducel, André; Zöllner, Tanja; Maercker, Andreas; Karl, Anke

    2006-11-01

    This study examined whether patients with posttraumatic stress disorder (PTSD) related to motor vehicle accidents (MVAs) would show an abnormal pattern of electroencephalographic (EEG) alpha asymmetries, which has been proposed for particular types of anxiety. Patients with PTSD (n = 22) or subsyndromal PTSD (n = 21), traumatized controls without PTSD (non-PTSD with MVA; n = 21), and healthy controls without MVA (n = 23) underwent measurement of EEG activity during baseline and exposure to a neutral, a positive, a negative, and an accident-related picture. Differences in brain asymmetry between groups were observed only during exposure to trauma-related material. PTSD and subsyndromal PTSD patients showed a pattern of enhanced right anterior and posterior activation, whereas non-PTSD with MVA participants showed the opposite pattern. Furthermore, posterior asymmetry in nontraumatized healthy controls varied with gender, with female participants showing a pattern of higher right posterior activation. The results support the hypothesis that symptomatic MVA survivors are characterized by a pattern of right hemisphere activation that is associated with anxious arousal and symptoms of PTSD during processing of trauma-specific information. (c) 2006 APA, all rights reserved.

  9. Effects of on-board storage and electrical stunning of wild cod (Gadus morhua) and haddock (Melanogrammus aeglefinus) on brain and heart activity

    NARCIS (Netherlands)

    Lambooij, E.; Digre, H.; Reimert, H.G.M.; Aursand, I.G.; Grimso, L.; Vis, van de J.W.

    2012-01-01

    Cod and haddock captured with commercial trawling gear were taken immediately after landing on deck to on-board storage in dry bins for measuring brain and heart activity, and behaviour. Other groups were first stored in holding tanks and then electrically stunned with a prototype "dry stunner". For

  10. Learning-Related Brain-Electrical Activity Dynamics Associated with the Subsequent Impact of Learnt Action-Outcome Associations

    Directory of Open Access Journals (Sweden)

    Fabian Baum

    2017-05-01

    Full Text Available Goal-directed behavior relies on the integration of anticipated outcomes into action planning based on acquired knowledge about the current contingencies between behavioral responses (R and desired outcomes (O under specific stimulus conditions (S. According to ideomotor theory, bidirectional R-O associations are an integral part of this knowledge structure. Previous EEG studies have identified neural activity markers linked to the involvement of such associations, but the initial acquisition process has not yet been characterized. The present study thus examined brain-electrical activity dynamics during the rapid acquisition of novel bidirectional R-O associations during instructed S-R learning. Within a trial, we inspected response-locked and stimulus-locked activity dynamics in order to identify markers linked to the forward and backward activation of bidirectional R-O associations as they were being increasingly strengthened under forced choice conditions. We found that a post-response anterior negativity following auditory outcomes was increasingly attenuated as a function of the acquired association strength. This suggests that previously reported action-induced sensory attenuation effects under extensively trained free choice conditions can be established within few repetitions of specific R-O pairings under forced choice conditions. Furthermore, we observed the even more rapid development of a post-response but pre-outcome fronto-central positivity which was reduced for high R-O learners which might indicate the rapid deployment of preparatory attention towards predictable outcomes. Finally, we identified a learning-related stimulus-locked activity modulation within the visual P1-N1 latency range which might reflect the multi-sensory integration of the perceived antecedent visual stimulus the anticipated auditory outcome.

  11. Slow oscillation electrical brain stimulation during waking promotes EEG theta activity and memory encoding

    DEFF Research Database (Denmark)

    Kirov, Roumen; Weiss, Carsten; Siebner, Hartwig R

    2009-01-01

    The application of transcranial slow oscillation stimulation (tSOS; 0.75 Hz) was previously shown to enhance widespread endogenous EEG slow oscillatory activity when applied during a sleep period characterized by emerging endogenous slow oscillatory activity. Processes of memory consolidation...... in a marked and widespread increase in EEG theta (4-8 Hz) activity. During wake, tSOS did not enhance consolidation of memories when applied after learning, but improved encoding of hippocampus-dependent memories when applied during learning. We conclude that the EEG frequency and related memory processes...

  12. Patterns of Brain Electrical Activity during Facial Signs of Emotion in 10-Month-Old Infants.

    Science.gov (United States)

    Fox, Nathan A.; Davidson, Richard J.

    1988-01-01

    Examined were electroencephalogram (EEG) asymmetries during the presence of discrete facial signs of emotion among 10-month-old infants who were tested in a standard stranger- and mother-approach paradigm that included a brief separation from mother. Data underscore the usefulness of EEG measures of hemispheric activation in differentiating among…

  13. Emergency Department Triage of Traumatic Head Injury Using a Brain Electrical Activity Biomarker: A Multisite Prospective Observational Validation Trial.

    Science.gov (United States)

    Hanley, Daniel; Prichep, Leslie S; Bazarian, Jeffrey; Huff, J Stephen; Naunheim, Rosanne; Garrett, John; Jones, Elizabeth B; Wright, David W; O'Neill, John; Badjatia, Neeraj; Gandhi, Dheeraj; Curley, Kenneth C; Chiacchierini, Richard; O'Neil, Brian; Hack, Dallas C

    2017-05-01

    A brain electrical activity biomarker for identifying traumatic brain injury (TBI) in emergency department (ED) patients presenting with high Glasgow Coma Scale (GCS) after sustaining a head injury has shown promise for objective, rapid triage. The main objective of this study was to prospectively evaluate the efficacy of an automated classification algorithm to determine the likelihood of being computed tomography (CT) positive, in high-functioning TBI patients in the acute state. Adult patients admitted to the ED for evaluation within 72 hours of sustaining a closed head injury with GCS 12 to 15 were candidates for study. A total of 720 patients (18-85 years) meeting inclusion/exclusion criteria were enrolled in this observational, prospective validation trial, at 11 U.S. EDs. GCS was 15 in 97%, with the first and third quartiles being 15 (interquartile range = 0) in the study population at the time of the evaluation. Standard clinical evaluations were conducted and 5 to 10 minutes of electroencephalogram (EEG) was acquired from frontal and frontal-temporal scalp locations. Using an a priori derived EEG-based classification algorithm developed on an independent population and applied to this validation population prospectively, the likelihood of each subject being CT+ was determined, and performance metrics were computed relative to adjudicated CT findings. Sensitivity of the binary classifier (likely CT+ or CT-) was 92.3% (95% confidence interval [CI] = 87.8%-95.5%) for detection of any intracranial injury visible on CT (CT+), with specificity of 51.6% (95% CI = 48.1%-55.1%) and negative predictive value (NPV) of 96.0% (95% CI = 93.2%-97.9%). Using ternary classification (likely CT+, equivocal, likely CT-) demonstrated enhanced sensitivity to traumatic hematomas (≥1 mL of blood), 98.6% (95% CI = 92.6%-100.0%), and NPV of 98.2% (95% CI = 95.5%-99.5%). Using an EEG-based biomarker high accuracy of predicting the likelihood of being CT+ was obtained, with

  14. Changes in brain electrical activity after cognitive behavioral therapy for posttraumatic stress disorder in patients injured in motor vehicle accidents.

    Science.gov (United States)

    Rabe, Sirko; Zoellner, Tanja; Beauducel, Andrë; Maercker, Andreas; Karl, Anke

    2008-01-01

    To explore changes for the first time in neural processing due to effective cognitive behavioral therapy (CBT) in posttraumatic stress disorder (PTSD) after severe motor vehicle accidents. Recent studies have highlighted the role of right hemisphere activation during withdrawal-related emotions (e.g., anxiety). There has been little research on changes in brain function due to cognitive-behavioral interventions in anxiety disorders. We conducted a randomized, controlled trial comparing cognitive-behavioral therapy with an assessment-only Wait-list condition. Spontaneous electroencephalographic activity was recorded from left and right anterior and posterior regions in participants with PTSD/subsyndromal PTSD receiving CBT (n = 17) before and after a CBT program. Wait-list controls (n = 18) were investigated before and after 3 months. At the pretreatment assessment, a pattern of increased right-sided activation during exposure to a trauma-related picture (relative to a neutral picture) was observed in both CBT and Wait-list participants. At posttreatment, there was a greater reduction of right anterior activation in the CBT group as compared with Wait-list controls. Across both groups, PTSD symptom reduction was significantly positively correlated with a decrease in right anterior activation to the trauma stimulus. These findings suggest that effective CBT treatment of PTSD may be accompanied by adaptive changes in asymmetrical brain function. Future studies are needed to confirm our findings.

  15. A randomized, controlled, double-blind pilot study of the effects of cranial electrical stimulation on activity in brain pain processing regions in individuals with fibromyalgia.

    Science.gov (United States)

    Taylor, Ann Gill; Anderson, Joel G; Riedel, Shannon L; Lewis, Janet E; Bourguignon, Cheryl

    2013-01-01

    To investigate the effects of microcurrent cranial electrical stimulation (CES) therapy on activity in pain processing brain regions. A randomized, controlled, three-group, double-blind pilot study. Persons with physician-diagnosed fibromyalgia. Active CES device, sham device, and usual care alone. Those individuals using the active device had a greater decrease in average pain (P = .023) than individuals using the sham device or receiving usual care alone over time. Preliminary analyses of the functional magnetic resonance imaging data on a subset of six participants from each of the two device groups show that individuals using an active CES device had a decrease in activation in the pain processing regions of the brain compared to those using a sham device. The observed decrease in activation in the pain processing regions may indicate a decrease in neural activity in these regions that may be related to decreased pain. This is the first randomized, controlled trial of CES in patients diagnosed with fibromyalgia to report functional magnetic resonance imaging data. Copyright © 2013 Elsevier Inc. All rights reserved.

  16. Integrative assessment of kick boxers’ brain blood circulation and bio-electrical activity in conditions of correction technologies’ application

    Directory of Open Access Journals (Sweden)

    Romanov Y.N.

    2016-06-01

    Full Text Available Purpose: to scientifically substantiate the role of para-vertebral impacts on blood circulation and bio-electrical activity of kick boxers’ cortex. Material: in the research participated kick boxers (main group, n=62 and university students (control group, n=25 of 18-23 years’ age. Assessment of para-vertebral impacts with device Armos and classic massage was fulfilled with the help of the following methodic: trans-cranial dopplerography of head main arteries and cortex EEG of the tested. Results: it was found that with the help of para-vertebral impacts by device Armos linear velocity of cerebral blood flow reduces to normal limits and in- and inter-hemispheres’ interaction strength increases. Conclusions: para-vertebral impacts by device Armos activate integrative processes and inter-hemispheres’ interactions of different cortex areas of kick boxers. It can witness about better formation of functional systems, ensuring sports efficiency.

  17. The effects of typical and atypical antipsychotics on the electrical activity of the brain in a rat model

    Directory of Open Access Journals (Sweden)

    Oytun Erbaş

    2013-09-01

    Full Text Available Objective: Antipsychotic drugs are known to have strongeffect on the bioelectric activity in the brain. However,some studies addressing the changes on electroencephalography(EEG caused by typical and atypical antipsychoticdrugs are conflicting. We aimed to compare the effectsof typical and atypical antipsychotics on the electricalactivity in the brain via EEG recordings in a rat model.Methods: Thirty-two Sprague Dawley adult male ratswere used in the study. The rats were divided into fivegroups, randomly (n=7, for each group. The first groupwas used as control group and administered 1 ml/kg salineintraperitoneally (IP. Haloperidol (1 mg/kg (group 2,chlorpromazine (5 mg/kg (group 3, olanzapine (1 mg/kg(group 4, ziprasidone (1 mg/ kg (group 5 were injectedIP for five consecutive days. Then, EEG recordings ofeach group were taken for 30 minutes.Results: The percentages of delta and theta waves inhaloperidol, chlorpromazine, olanzapine and ziprasidonegroups were found to have a highly significant differencecompared with the saline administration group (p<0.001.The theta waves in the olanzapine and ziprasidonegroups were increased compared with haloperidol andchlorpromazine groups (p<0.05.Conclusion: The typical and atypical antipsychotic drugsmay be risk factor for EEG abnormalities. This studyshows that antipsychotic drugs should be used with caution.J Clin Exp Invest 2013; 4 (3: 279-284Key words: Haloperidol, chlorpromazine, olanzapine,ziprasidone, EEG, rat

  18. Effect of the 5-HT(1A) partial agonist buspirone on regional brain electrical activity in man: a functional neuroimaging study using low-resolution electromagnetic tomography (LORETA).

    Science.gov (United States)

    Anderer, P; Saletu, B; Pascual-Marqui, R D

    2000-12-04

    In a double-blind, placebo-controlled study, the effects of 20 mg buspirone - a 5-HT(1A) partial agonist - on regional electrical generators within the human brain were investigated utilizing three-dimensional EEG tomography. Nineteen-channel vigilance-controlled EEG recordings were carried out in 20 healthy subjects before and 1, 2, 4, 6 and 8 h after drug intake. Low-resolution electromagnetic tomography (LORETA; Key Institute for Brain-Mind Research, software: http://www.keyinst.unizh.ch) was computed from spectrally analyzed EEG data, and differences between drug- and placebo-induced changes were displayed as statistical parametric maps. Data were registered to the Talairach-Tournoux human brain atlas available as a digitized MRI (McConnell Brain Imaging Centre: http://www.bic.mni.mcgill.ca). At the pharmacodynamic peak (1st hour), buspirone increased theta and decreased fast alpha and beta sources. Areas of theta increase were mainly the left temporo-occipito-parietal and left prefrontal cortices, which is consistent with PET studies on buspirone-induced decreases in regional cerebral blood flow and fenfluramine-induced serotonin activation demonstrated by changes in regional cerebral glucose metabolism. In later hours (8th hour) with lower buspirone plasma levels, delta, theta, slow alpha and fast beta decreased, predominantly in the prefrontal and anterior limbic lobe. Whereas the results of the 1st hour speak for a slight CNS sedation (more in the sense of relaxation), those obtained in the 8th hour indicate activation. Thus, LORETA may provide useful and direct information on drug-induced changes in central nervous system function in man.

  19. Resting and reactive frontal brain electrical activity (EEG among a non-clinical sample of socially anxious adults: Does concurrent depressive mood matter?

    Directory of Open Access Journals (Sweden)

    Elliott A Beaton

    2008-03-01

    Full Text Available Elliott A Beaton1, Louis A Schmidt2, Andrea R Ashbaugh2,5, Diane L Santesso2, Martin M Antony1,3,4, Randi E McCabe1,31Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, Ontario, Canada; 2Department of Psychology, Neuroscience and Behaviour, McMaster University, Hamilton, Ontario, Canada; 3Anxiety Treatment and Research Centre, St. Joseph’s Healthcare, Hamilton, Ontario, Canada; 4Department of Psychology, Ryerson University, Toronto, Ontario, Canada; 5Concordia University, Montreal, Quebec, CanadaAbstract: A number of studies have noted that the pattern of resting frontal brain electrical activity (EEG is related to individual differences in affective style in healthy infants, children, and adults and some clinical populations when symptoms are reduced or in remission. We measured self-reported trait shyness and sociability, concurrent depressive mood, and frontal brain electrical activity (EEG at rest and in anticipation of a speech task in a non-clinical sample of healthy young adults selected for high and low social anxiety. Although the patterns of resting and reactive frontal EEG asymmetry did not distinguish among individual differences in social anxiety, the pattern of resting frontal EEG asymmetry was related to trait shyness after controlling for concurrent depressive mood. Individuals who reported a higher degree of shyness were likely to exhibit greater relative right frontal EEG activity at rest. However, trait shyness was not related to frontal EEG asymmetry measured during the speech-preparation task, even after controlling for concurrent depressive mood. These findings replicate and extend prior work on resting frontal EEG asymmetry and individual differences in affective style in adults. Findings also highlight the importance of considering concurrent emotional states of participants when examining psychophysiological correlates of personality.Keywords: social anxiety, shyness, sociability

  20. Effects of the South American psychoactive beverage ayahuasca on regional brain electrical activity in humans: a functional neuroimaging study using low-resolution electromagnetic tomography.

    Science.gov (United States)

    Riba, Jordi; Anderer, Peter; Jané, Francesc; Saletu, Bernd; Barbanoj, Manel J

    2004-01-01

    Ayahuasca, a South American psychotropic plant tea obtained from Banisteriopsis caapi and Psychotria viridis, combines monoamine oxidase-inhibiting beta-carboline alkaloids with N,N-dimethyltryptamine (DMT), a psychedelic agent showing 5-HT(2A) agonist activity. In a clinical research setting, ayahuasca has demonstrated a combined stimulatory and psychedelic effect profile, as measured by subjective effect self-assessment instruments and dose-dependent changes in spontaneous brain electrical activity, which parallel the time course of subjective effects. In the present study, the spatial distribution of ayahuasca-induced changes in brain electrical activity was investigated by means of low-resolution electromagnetic tomography (LORETA). Electroencephalography recordings were obtained from 18 volunteers after the administration of a dose of encapsulated freeze-dried ayahuasca containing 0.85 mg DMT/kg body weight and placebo. The intracerebral power density distribution was computed with LORETA from spectrally analyzed data, and subjective effects were measured by means of the Hallucinogen Rating Scale (HRS). Statistically significant differences compared to placebo were observed for LORETA power 60 and 90 min after dosing, together with increases in all six scales of the HRS. Ayahuasca decreased power density in the alpha-2, delta, theta and beta-1 frequency bands. Power decreases in the delta, alpha-2 and beta-1 bands were found predominantly over the temporo-parieto-occipital junction, whereas theta power was reduced in the temporomedial cortex and in frontomedial regions. The present results suggest the involvement of unimodal and heteromodal association cortex and limbic structures in the psychological effects elicited by ayahuasca. Copyright 2004 S. Karger AG, Basel

  1. Electric Brain Stimulation No Better Than Meds for Depression: Study

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_166920.html Electric Brain Stimulation No Better Than Meds For Depression: ... can't find relief, stimulating the brain with electric impulses may help. But a new study by ...

  2. Parental Rearing Behavior Prospectively Predicts Adolescents' Risky Decision-Making and Feedback-Related Electrical Brain Activity

    Science.gov (United States)

    Euser, Anja S.; Evans, Brittany E.; Greaves-Lord, Kirstin; Huizink, Anja C.; Franken, Ingmar H. A.

    2013-01-01

    The present study examined the role of parental rearing behavior in adolescents' risky decision-making and the brain's feedback processing mechanisms. Healthy adolescent participants ("n" = 110) completed the EMBU-C, a self-report questionnaire on perceived parental rearing behaviors between 2006 and 2008 (T1). Subsequently, after an…

  3. Functional electrical stimulation improves brain perfusion in cranial trauma patients

    Directory of Open Access Journals (Sweden)

    Bárbara Juarez Amorim

    2011-08-01

    Full Text Available OBJECTIVE: Demonstrate brain perfusion changes due to neuronal activation after functional electrical stimulation (FES. METHOD: It was studied 14 patients with hemiplegia who were submitted to a program with FES during fourteen weeks. Brain perfusion SPECT was performed before and after FES therapy. These patients were further separated into 2 groups according to the hemiplegia cause: cranial trauma and major vascular insults. All SPECT images were analyzed using SPM. RESULTS: There was a significant statistical difference between the two groups related to patient's ages and extent of hypoperfusion in the SPECT. Patients with cranial trauma had a reduction in the hypoperfused area and patients with major vascular insult had an increase in the hypoperfused area after FES therapy. CONCLUSION: FES therapy can result in brain perfusion improvement in patients with brain lesions due to cranial trauma but probably not in patients with major vascular insults with large infarct area.

  4. Asynchronous presentation of global and local information reveals effects of attention on brain electrical activity specific to each level

    Directory of Open Access Journals (Sweden)

    Jorge eIglesias-Fuster

    2015-01-01

    Full Text Available The neural basis of selective attention within hierarchically organized Navon figures has been extensively studied with event related potentials (ERPs, by contrasting responses obtained when attending the global and the local echelons. The findings are inherently ambiguous because both levels are always presented together. Thus only a mixture of the brain responses to two levels can be observed. Here, we use a method that allows unveiling of global and local letters at distinct times, enabling estimation of separate ERPs related to each level. Two interspersed oddball streams were presented, each using letters from one level and comprised of frequent distracters and rare targets. Previous work and our Experiment 1 show that it is difficult to divide attention between two such streams of stimuli. ERP recording in Experiment 2 evinced an early selection negativity (SN, with latencies to the 50% area of about 266 ms for global distracters and 276 ms for local distracters that was larger for attended relative to unattended distracters. The SN was larger over right posterior occipito-temporal derivations for global stimuli and over left posterior occipito-temporal derivations for local stimuli (although the latter was less strongly lateralized. A discrimination negativity (DN, accompanied by a P3b was larger for attended targets relative to attended distracters, with latencies to the 50% area of about 316 ms for global stimuli and 301 ms for local stimuli, which presented a similar distribution for both levels over left temporo-parietal electrodes. The two negativities apparently index successive stages in the processing of a selected level within a compound figure. By resolving the ambiguity of traditional designs, our method allowed us to observe the effects of attention for each hierarchical level on its own.

  5. Increased prognostic accuracy of TBI when a brain electrical activity biomarker is added to loss of consciousness (LOC).

    Science.gov (United States)

    Hack, Dallas; Huff, J Stephen; Curley, Kenneth; Naunheim, Roseanne; Ghosh Dastidar, Samanwoy; Prichep, Leslie S

    2017-07-01

    Extremely high accuracy for predicting CT+ traumatic brain injury (TBI) using a quantitative EEG (QEEG) based multivariate classification algorithm was demonstrated in an independent validation trial, in Emergency Department (ED) patients, using an easy to use handheld device. This study compares the predictive power using that algorithm (which includes LOC and amnesia), to the predictive power of LOC alone or LOC plus traumatic amnesia. ED patients 18-85years presenting within 72h of closed head injury, with GSC 12-15, were study candidates. 680 patients with known absence or presence of LOC were enrolled (145 CT+ and 535 CT- patients). 5-10min of eyes closed EEG was acquired using the Ahead 300 handheld device, from frontal and frontotemporal regions. The same classification algorithm methodology was used for both the EEG based and the LOC based algorithms. Predictive power was evaluated using area under the ROC curve (AUC) and odds ratios. The QEEG based classification algorithm demonstrated significant improvement in predictive power compared with LOC alone, both in improved AUC (83% improvement) and odds ratio (increase from 4.65 to 16.22). Adding RGA and/or PTA to LOC was not improved over LOC alone. Rapid triage of TBI relies on strong initial predictors. Addition of an electrophysiological based marker was shown to outperform report of LOC alone or LOC plus amnesia, in determining risk of an intracranial bleed. In addition, ease of use at point-of-care, non-invasive, and rapid result using such technology suggests significant value added to standard clinical prediction. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Magnetic resonance electric property imaging of brain tissues.

    Science.gov (United States)

    Zhang, Xiaotong; Zhu, Shanan; He, Bin

    2009-01-01

    The electric properties (EPs) of brain tissues, i.e., the electric conductivity and permittivity, can provide important information for diagnosis of various brain disorders. A high-field MRI system is accompanied by significant wave propagation effects, and the radio frequency (RF) radiation is dependent on EPs of the biological tissue. Based on the measurement of the active transverse magnetic component of the applied RF field (known as B1-mapping technique), we have developed a dual-excitation algorithm, which uses two sets of measured B1 data, to noninvasively reconstruct the biological tissue's electric properties. A series of computer simulations were conducted to evaluate the feasibility and performance of the proposed method on a 3-D head model within a birdcage coil and a transverse electromagnetic coil. Compared with other B1-mapping based reconstruction algorithms, our approach provides superior performance without the need for iterative computations. The present simulation results indicate good reconstruction of electric properties of brain tissues from noninvasive MRI B1 mapping.

  7. Frequency-spatial organization of brain electrical activity in creative verbal thought: the role of the gender factor.

    Science.gov (United States)

    Razumnikova, O M; Bryzgalov, A O

    2006-07-01

    Gender-related differences in the EEG correlates of creative thought were studied by mapping EEG power during performance of a Remote Associations Task as compared with verbal word-generation and simple association tasks. Right-handed students (18 male, 21 female) took part in the studies. Gender-related differences were seen in the factor structure of measures of verbal activity and in the larger number of words generated for a given letter in women than in men. In terms of the originality of the associations, men and women showed no significant difference, though the dynamics of the power of the beta-2 rhythm during creative thought differed. In males, the search for original associations was accompanied by increases in beta-2 power in both hemispheres at the initial stages of performing the task, with local increases in the beta-2 rhythm in the central parts of the cortex at the end of testing. In women, the increase in beta-2 power was initially greater in the right hemisphere than the left, while there was a relative decrease in beta activity in the parietal-temporal areas of the cortex and an increase in the left anterior frontal areas at the terminal stage of task performance. It is suggested that creative verbal thought is based mostly on an "insight" strategy in males, while women additionally use an "intellectual" strategy.

  8. The effects of inhibitory control training on alcohol consumption, implicit alcohol-related cognitions and brain electrical activity.

    Science.gov (United States)

    Bowley, Claire; Faricy, Cameron; Hegarty, Bronwyn; J Johnstone, Stuart; L Smith, Janette; J Kelly, Peter; A Rushby, Jacqueline

    2013-09-01

    This study aimed to replicate findings that alcohol consumption and positive implicit beer-related cognitions can be reduced using inhibitory control (IC) training, with the addition of an active training control. Frontal EEG asymmetry, an objective psychophysiological index of approach motivation, was used as a dependent measure to examine training outcomes. Participants were randomly assigned to one of two IC training conditions (Beer NoGo or Beer Go) or a Brief Alcohol Intervention (BAI) (i.e. the active training control). The IC training tasks consistently paired a stimulus that required a response with images of water (Beer NoGo) or images of beer (Beer Go). Alcohol consumption and implicit beer-related cognitions were measured at pre-training, post-training and at one week follow-up. Frontal EEG asymmetry was recorded during a passive image viewing task that presented neutral, healthy, and beer stimuli - at pre-training, post-training and follow-up. Participants in the Beer NoGo and BAI conditions consumed less beer in a taste test immediately after training than Beer Go participants, suggesting that IC training may be as effective as the already established BAI. The taste test findings were in line with the frontal EEG asymmetry data, which indicated that approach motivation for beer stimuli was altered in the expected directions. However, the positive correlation between post-training frontal EEG asymmetry data and taste test consumption was not significant. While there were no significant changes in implicit beer-related cognitions following training, a trending positive relationship between implicit beer-related cognitions at post-training and taste test consumption was reported. Further exploration addressing the limitations of the current study is required in order to clarify the implications of these findings. Copyright © 2013 Elsevier B.V. All rights reserved.

  9. [Frequency-spatial organization of brain electrical activity in creative verbal thinking: role of the gender factor].

    Science.gov (United States)

    Razumnikova, O M; Bryzgalova, A O

    2005-01-01

    Gender differences in EEG patterns associated with verbal creativity were studied by EEG mapping. The EEGs of 18 males and 21 females (right-handed university students) were recorded during a performance of Remote Associates Task (RAT) compared with the letter-fluency and simple associate's tasks. Gender differences were found in a factor structure of the indices of verbal thinking and a score of generating words was greater in women than men. No significant gender differences in originality of associations were revealed, however, gender-related differences in the EEG-patterns were found at the final and initial stages of RAT. In men, the beta2-power was increased in both hemispheres at the beginning of test. To the end of testing, the power of oscillations in the beta2 band increased only in the central part of the cortex. In women, the beta2-power was increased to a greater extent in the right than in the left hemisphere at the initial stage of task performance, whereas the final stage was characterized by a relative decrease in beta-activity in parietotemporal cortical regions and increase in the left prefrontal region. It is suggested that the verbal creative thinking in men is based mostly on "insight" strategy whereas women additionally involve the "intellectual" strategy.

  10. Salicylate-Induced Suppression of Electrically Driven Activity in Brain Slices from the Auditory Cortex of Aging Mice

    Directory of Open Access Journals (Sweden)

    Minoru Namikawa

    2017-12-01

    Full Text Available The prevalence of tinnitus is known to increase with age. The age-dependent mechanisms of tinnitus may have important implications for the development of new therapeutic treatments. High doses of salicylate can be used experimentally to induce transient tinnitus and hearing loss. Although accumulating evidence indicates that salicylate induces tinnitus by directly targeting neurons in the peripheral and central auditory systems, the precise effect of salicylate on neural networks in the auditory cortex (AC is unknown. Here, we examined salicylate-induced changes in stimulus-driven laminar responses of AC slices with salicylate superfusion in young and aged senescence-accelerated-prone (SAMP and -resistant (SAMR mice. Of the two strains, SAMP1 is known to be a more suitable model of presbycusis. We recorded stimulus-driven laminar local field potential (LFP responses at multi sites in AC slice preparations. We found that for all AC slices in the two strains, salicylate always reduced stimulus-driven LFP responses in all layers. However, for the amplitudes of the LFP responses, the two senescence-accelerated mice (SAM strains showed different laminar properties between the pre- and post-salicylate conditions, reflecting strain-related differences in local circuits. As for the relationships between auditory brainstem response (ABR thresholds and the LFP amplitude ratios in the pre- vs. post-salicylate condition, we found negative correlations in layers 2/3 and 4 for both older strains, and in layer 5 (L5 in older SAMR1. In contrast, the GABAergic agonist muscimol (MSC led to positive correlations between ABR thresholds and LFP amplitude ratios in the pre- vs. post-MSC condition in younger SAM mice from both strains. Further, in younger mice, salicylate decreased the firing rate in AC L4 pyramidal neurons. Thus, salicylate can directly reduce neural excitability of L4 pyramidal neurons and thereby influence AC neural circuit activity. That we

  11. Neurocortical electrical activity tomography in chronic schizophrenics

    Directory of Open Access Journals (Sweden)

    Veiga Heloisa

    2003-01-01

    Full Text Available Functional imaging of brain electrical activity was performed in 25 chronic medicated schizophrenics and 40 controls, analyzing the classical frequency bands (delta, theta, alpha, and beta of 19-channel EEG during resting state to identify brain regions with deviant activity of different functional significances, using LORETA (Low Resolution Tomography and SPM99 (Statistical Parametric Mapping. Patients differed from controls due to an excess of slow activity comprising delta + theta frequency bands (inhibitory pattern located at the right middle frontal gyrus, right inferior frontal gyrus, and right insula, as well as at the bilateral anterior cingulum with a left preponderance. The high temporal resolution of EEG enables the specification of the deviations not only as an excess or a deficit of brain electrical activity, but also as inhibitory (delta, theta, normal (alpha, and excitatory (beta activities. These deviations point out to an impaired functional brain state consisting of inhibited frontal and prefrontal areas that may result in inadequate treatment of externally or internally generated information.

  12. In vivo assessment of human brain oscillations during application of transcranial electric currents

    NARCIS (Netherlands)

    Soekadar, S.R.; Witkowski, M.; Garcia Cossio, E.; Birbaumer, N.; Robinson, S.E.; Cohen, L.G.

    2013-01-01

    Brain oscillations reflect pattern formation of cell assemblies’ activity, which is often disturbed in neurological and psychiatric diseases like depression, schizophrenia and stroke. In the neurobiological analysis and treatment of these conditions, transcranial electric currents applied to the

  13. [Effect of Transcutaneous Electrical Acupoint Stimulation on Post-surgical Gastrointestinal Function, Autonomic Nerve Activities and Plasma Brain-gut Peptide Levels in Patients Undergoing Gastrointestinal Surgery].

    Science.gov (United States)

    Li, Jin-Jin; Zhao, Wen-Sheng; Shao, Xiao-Mei; Yang, Ai-Ming; Zhang, Fang-Fang; Fang, Jian-Qiao

    2016-06-25

    To observe the effect of transcutaneous electrical acupoint stimulation (TEAS) on ileus-postope-rative gastrointestinal functions and plasma ghrelin, motilin, and gastrin contents, and heart rate variability (HRV) in patients undergoing gastrointestinal surgery, so as to explore the interaction of vagus-brain-gut peptide. A total of 58 patients undergoing elective gastrointestinal surgery were randomly assigned to TEAS (n=29) and sham-TEAS group (n=29, patients had no subjective sensation to 1 mA TEAS, thus, being considered to be sham-TEAS). TEAS (2 Hz/100 Hz, 6-8 mA for LI 4-PC 6, 12-18 mA for ST 36-SP 6) was applied to bilateral Hegu (LI 4)-Neiguan (PC 6) from 30 min pre-operation to the end of the operation and to bilateral LI 4-PC 6 and Zusanli (ST 36)-Sanyinjiao (SP 6) for 30 minutes twice daily in 3 consecutive post-operative days. ECGs of 12 leads were recorded to analyze different parameters of HRV from 2 days before and 4 days after surgery. Plasma ghrelin, motilin and gastrin contents were assayed by radioimmunoassay, and the patients' first bowel sound, first independent walk, first flatus, first solid food-intake and first defecation were recorded to evaluate the recovery state of gastrointestinal motility. Postoperative gastrointestinal motility:compared with the sham-TEAS group, the first bowel sound and the first defecation after surgery appeared apparently earlier in the TEAS group (P0.05). HRV domains:in comparison with pre-surgery, the levels of low frequency (LF) and high frequency (HF) of frequency domain (FD) and root mean square of successive differences (rMSSD) of the time domain (TD) of HRV 4 days after surgery were significantly decreased in the sham-TEAS group (P0.05). Compared with the sham-TEAS group, the HF and rMSSD levels were significantly increased in the TEAS group 4 days after the surgery (P<0.05). No significant differences were found between the two groups in the levels of very low frequency, LF and LF/HF levels of FD, and

  14. A simple procedure to synchronize concurrent measurements of gait and brain electrical activity and preliminary results from a pilot measurement involving motor-cognitive dual-tasking in healthy older and young volunteers.

    Science.gov (United States)

    Marcar, Valentine L; Bridenbaugh, Stephanie A; Kool, Jan; Niedermann, Karin; Kressig, Reto W

    2014-05-15

    The ability to record brain activity under normal walking conditions is the key to studying supraspinal influence on spinal gait control. We developed a procedure of synchronizing an electronic walkway (GAITRite, CIR Systems Inc.) with a multi-channel, wireless EEG-system (BrainAmp, Brainproducts). To assess the practicability of our procedure we performed a proof of concept measurement involving concurrently recording gait pattern and brain electrical activity in two elderly and two young participants. This measurement enabled us to assess the synchronization of the two data sets under realistic conditions. Only carrying a filled water glass reduced gait regularity in the elderly. In the young gait regularity was constant across all tasks. This concurs with previous findings reporting a task specific influence on gait. Carrying a full water glass also led to an increase in the power of the EEG gamma-band oscillations in frontal cortex of the elderly, but led to a decrease in the young participants. Carrying a full glass increased activity in frontal cortex of the elderly but decreased it in the young participants. At present, concurrent recording of gait pattern and electrical brain activity requires participants to walk on a treadmill. Our procedure enables these measurements to be made under natural walking conditions. This allows measurements of brain activity during walking in special needs groups such as children, the elderly or the infirm under near natural conditions. Our procedure for synchronizing EEG and gait proved simple, reliable and generated data of high-quality. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

  15. Chaos and Brain Wave Activity: Measures of Irregular Time Series

    National Research Council Canada - National Science Library

    West, Bruce

    1988-01-01

    Physiological measurements of the electrical activity of the brain may provide the predictive information necessary for a sensitive measure of the attention state of an airplane pilot or air traffic controller...

  16. Noninvasive Deep Brain Stimulation via Temporally Interfering Electric Fields

    OpenAIRE

    Grossman, Nir; De Bono, David; Dedic, Nina; Kodandaramaiah, Suhasa B.; Rudenko, Andrii; Suk, Ho-Jun; Cassara, Antonio M.; Neufeld, Esra; Kuster, Niels; Tsai, Li-Huei; Pascual-Leone, Alvaro; Boyden, Edward S.

    2017-01-01

    We report a noninvasive strategy for electrically stimulating neurons at depth. By delivering to the brain multiple electric fields at frequencies too high to recruit neural firing, but which differ by a frequency within the dynamic range of neural firing, we can electrically stimulate neurons throughout a region where interference between the multiple fields results in a prominent electric field envelope modulated at the difference frequency. We validated this temporal interference (TI) conc...

  17. Look at Epilepsy: Electrical Outbursts in the Brain

    Science.gov (United States)

    ... November 2015 Print this issue A Look at Epilepsy Electrical Outbursts in the Brain En español Send us your comments When you hear the word epilepsy, you might think of intense seizures with muscle ...

  18. Look at Epilepsy: Electrical Outbursts in the Brain

    Science.gov (United States)

    ... Print this issue Health Capsule A Look at Epilepsy Electrical Outbursts in the Brain En español Send us your comments When you hear the word epilepsy, you might think of intense seizures with muscle ...

  19. Physical activity and brain development.

    Science.gov (United States)

    Gomes da Silva, Sérgio; Arida, Ricardo Mario

    2015-01-01

    Brain development is a complex process, and stimuli during this developmental period may modulate the brain's functional maturation and determine its lifelong integrity. Human and animal studies have shown that environmental stimuli such as physical activity habits seem to have a favorable influence on brain development. Research on humans has demonstrated improvement in cognitive performance in the children of women who exercised regularly throughout pregnancy and in individuals who were physically active during childhood and adolescence. Investigations using animal models have also reported that physical activity improves the cognitive function of developing rats. In this review, we will present the neurobiological mechanisms of such effects.

  20. Recording of brain activity across spatial scales

    NARCIS (Netherlands)

    Lewis, C.M.; Bosman, C.A.; Fries, P.

    2015-01-01

    Brain activity reveals exquisite coordination across spatial scales, from local microcircuits to brain-wide networks. Understanding how the brain represents, transforms and communicates information requires simultaneous recordings from distributed nodes of whole brain networks with single-cell

  1. Brain Gym. Simple Activities for Whole Brain Learning.

    Science.gov (United States)

    Dennison, Paul E.; Dennison, Gail E.

    This booklet contains simple movements and activities that are used with students in Educational Kinesiology to enhance their experience of whole brain learning. Whole brain learning through movement repatterning and Brain Gym activities enable students to access those parts of the brain previously unavailable to them. These movements of body and…

  2. Electric Field Encephalography as a tool for functional brain research: a modeling study.

    Directory of Open Access Journals (Sweden)

    Yury Petrov

    Full Text Available We introduce the notion of Electric Field Encephalography (EFEG based on measuring electric fields of the brain and demonstrate, using computer modeling, that given the appropriate electric field sensors this technique may have significant advantages over the current EEG technique. Unlike EEG, EFEG can be used to measure brain activity in a contactless and reference-free manner at significant distances from the head surface. Principal component analysis using simulated cortical sources demonstrated that electric field sensors positioned 3 cm away from the scalp and characterized by the same signal-to-noise ratio as EEG sensors provided the same number of uncorrelated signals as scalp EEG. When positioned on the scalp, EFEG sensors provided 2-3 times more uncorrelated signals. This significant increase in the number of uncorrelated signals can be used for more accurate assessment of brain states for non-invasive brain-computer interfaces and neurofeedback applications. It also may lead to major improvements in source localization precision. Source localization simulations for the spherical and Boundary Element Method (BEM head models demonstrated that the localization errors are reduced two-fold when using electric fields instead of electric potentials. We have identified several techniques that could be adapted for the measurement of the electric field vector required for EFEG and anticipate that this study will stimulate new experimental approaches to utilize this new tool for functional brain research.

  3. Efficacy of brain-computer interface-driven neuromuscular electrical stimulation for chronic paresis after stroke.

    Science.gov (United States)

    Mukaino, Masahiko; Ono, Takashi; Shindo, Keiichiro; Fujiwara, Toshiyuki; Ota, Tetsuo; Kimura, Akio; Liu, Meigen; Ushiba, Junichi

    2014-04-01

    Brain computer interface technology is of great interest to researchers as a potential therapeutic measure for people with severe neurological disorders. The aim of this study was to examine the efficacy of brain computer interface, by comparing conventional neuromuscular electrical stimulation and brain computer interface-driven neuromuscular electrical stimulation, using an A-B-A-B withdrawal single-subject design. A 38-year-old male with severe hemiplegia due to a putaminal haemorrhage participated in this study. The design involved 2 epochs. In epoch A, the patient attempted to open his fingers during the application of neuromuscular electrical stimulation, irrespective of his actual brain activity. In epoch B, neuromuscular electrical stimulation was applied only when a significant motor-related cortical potential was observed in the electroencephalogram. The subject initially showed diffuse functional magnetic resonance imaging activation and small electro-encephalogram responses while attempting finger movement. Epoch A was associated with few neurological or clinical signs of improvement. Epoch B, with a brain computer interface, was associated with marked lateralization of electroencephalogram (EEG) and blood oxygenation level dependent responses. Voluntary electromyogram (EMG) activity, with significant EEG-EMG coherence, was also prompted. Clinical improvement in upper-extremity function and muscle tone was observed. These results indicate that self-directed training with a brain computer interface may induce activity- dependent cortical plasticity and promote functional recovery. This preliminary clinical investigation encourages further research using a controlled design.

  4. Electrical Guidance of Human Stem Cells in the Rat Brain

    Directory of Open Access Journals (Sweden)

    Jun-Feng Feng

    2017-07-01

    Full Text Available Limited migration of neural stem cells in adult brain is a roadblock for the use of stem cell therapies to treat brain diseases and injuries. Here, we report a strategy that mobilizes and guides migration of stem cells in the brain in vivo. We developed a safe stimulation paradigm to deliver directional currents in the brain. Tracking cells expressing GFP demonstrated electrical mobilization and guidance of migration of human neural stem cells, even against co-existing intrinsic cues in the rostral migration stream. Transplanted cells were observed at 3 weeks and 4 months after stimulation in areas guided by the stimulation currents, and with indications of differentiation. Electrical stimulation thus may provide a potential approach to facilitate brain stem cell therapies.

  5. Fueling and Imaging Brain Activation

    Directory of Open Access Journals (Sweden)

    Gerald A Dienel

    2012-05-01

    Full Text Available Metabolic signals are used for imaging and spectroscopic studies of brain function and disease and to elucidate the cellular basis of neuroenergetics. The major fuel for activated neurons and the models for neuron–astrocyte interactions have been controversial because discordant results are obtained in different experimental systems, some of which do not correspond to adult brain. In rats, the infrastructure to support the high energetic demands of adult brain is acquired during postnatal development and matures after weaning. The brain's capacity to supply and metabolize glucose and oxygen exceeds demand over a wide range of rates, and the hyperaemic response to functional activation is rapid. Oxidative metabolism provides most ATP, but glycolysis is frequently preferentially up-regulated during activation. Underestimation of glucose utilization rates with labelled glucose arises from increased lactate production, lactate diffusion via transporters and astrocytic gap junctions, and lactate release to blood and perivascular drainage. Increased pentose shunt pathway flux also causes label loss from C1 of glucose. Glucose analogues are used to assay cellular activities, but interpretation of results is uncertain due to insufficient characterization of transport and phosphorylation kinetics. Brain activation in subjects with low blood-lactate levels causes a brain-to-blood lactate gradient, with rapid lactate release. In contrast, lactate flooding of brain during physical activity or infusion provides an opportunistic, supplemental fuel. Available evidence indicates that lactate shuttling coupled to its local oxidation during activation is a small fraction of glucose oxidation. Developmental, experimental, and physiological context is critical for interpretation of metabolic studies in terms of theoretical models.

  6. Noninvasive Deep Brain Stimulation via Temporally Interfering Electric Fields.

    Science.gov (United States)

    Grossman, Nir; Bono, David; Dedic, Nina; Kodandaramaiah, Suhasa B; Rudenko, Andrii; Suk, Ho-Jun; Cassara, Antonino M; Neufeld, Esra; Kuster, Niels; Tsai, Li-Huei; Pascual-Leone, Alvaro; Boyden, Edward S

    2017-06-01

    We report a noninvasive strategy for electrically stimulating neurons at depth. By delivering to the brain multiple electric fields at frequencies too high to recruit neural firing, but which differ by a frequency within the dynamic range of neural firing, we can electrically stimulate neurons throughout a region where interference between the multiple fields results in a prominent electric field envelope modulated at the difference frequency. We validated this temporal interference (TI) concept via modeling and physics experiments, and verified that neurons in the living mouse brain could follow the electric field envelope. We demonstrate the utility of TI stimulation by stimulating neurons in the hippocampus of living mice without recruiting neurons of the overlying cortex. Finally, we show that by altering the currents delivered to a set of immobile electrodes, we can steerably evoke different motor patterns in living mice. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Electrical activity in muscle pain.

    Science.gov (United States)

    Cobb, C R; deVries, H A; Urban, R T; Luekens, C A; Bagg, R J

    1975-04-01

    The concept of muscle pain-spasm-pain vicious cycle has been challenged on the basis of inability to find electrical activity in the presence of palpable changes in fibrositic muscle. We produced muscle pain in the wrist extensor and paravertebral muscle groups of seven healthy subjects by injection of hypertonic saline (0.3 ml of 6% NaCl solution). The time course of the integrated muscle action potentials, roughly paralleled the time course of the developed pain in all but one subject for each muscle group. EMG recordings were made on one subject using both surface electrodes with amplifier sensitivity of 10 muV/cm and needle electrodes with an amplifier sensitivity of 100 muV/cm. Sequential recording showed clear evidence of electrical activity from the surface electrode and high sensitivity whereas the combination of the needle electrode with lower sensitivity showed no electrical activity whatever. We conclude that even mild muscle spasm is accompanied by muscular hyperactivity which can be evaluated by appropriate EMG techniques. There appears to be no reason to challenge the widely accepted concept of pain-spasm-pain as stated by Travell, Rinzler and Herman.

  8. Electric field calculations in brain stimulation based on finite elements

    DEFF Research Database (Denmark)

    Windhoff, Mirko; Opitz, Alexander; Thielscher, Axel

    2013-01-01

    The need for realistic electric field calculations in human noninvasive brain stimulation is undisputed to more accurately determine the affected brain areas. However, using numerical techniques such as the finite element method (FEM) is methodologically complex, starting with the creation...... elements. The latter is crucial to guarantee the numerical robustness of the FEM calculations. The pipeline will be released as open-source, allowing for the first time to perform realistic field calculations at an acceptable methodological complexity and moderate costs....

  9. Electrical bioimpedance enabling prompt intervention in traumatic brain injury

    Science.gov (United States)

    Seoane, Fernando; Atefi, S. Reza

    2017-05-01

    Electrical Bioimpedance (EBI) is a well spread technology used in clinical practice across the world. Advancements in Textile material technology with conductive textile fabrics and textile-electronics integration have allowed exploring potential applications for Wearable Measurement Sensors and Systems exploiting. The sensing principle of electrical bioimpedance is based on the intrinsic passive dielectric properties of biological tissue. Using a pair of electrodes, tissue is electrically stimulated and the electrical response can be sensed with another pair of surface electrodes. EBI spectroscopy application for cerebral monitoring of neurological conditions such as stroke and perinatal asphyxia in newborns have been justified using animal studies and computational simulations. Such studies have shown proof of principle that neurological pathologies indeed modify the dielectric composition of the brain that is detectable via EBI. Similar to stroke, Traumatic Brain Injury (TBI) also affects the dielectric properties of brain tissue that can be detected via EBI measurements. Considering the portable and noninvasive characteristics of EBI it is potentially useful for prehospital triage of TBI patients where. In the battlefield blast induced Traumatic Brain Injuries are very common. Brain damage must be assessed promptly to have a chance to prevent severe damage or eventually death. The relatively low-complexity of the sensing hardware required for EBI sensing and the already proven compatibility with textile electrodes suggest the EBI technology is indeed a candidate for developing a handheld device equipped with a sensorized textile cap to produce an examination in minutes for enabling medically-guided prompt intervention.

  10. Syncing your brain: electric currents to enhance cognition

    NARCIS (Netherlands)

    Schutter, D.J.L.G.

    2014-01-01

    Contemporary studies in cognitive neuroscience demonstrate that cognitive performance can be enhanced by applying exogenous low-intensity electric currents to the brain. These findings have resulted in a widespread interest from both scientists and popular media, particularly, regarding the host of

  11. Ownership of an artificial limb induced by electrical brain stimulation.

    Science.gov (United States)

    Collins, Kelly L; Guterstam, Arvid; Cronin, Jeneva; Olson, Jared D; Ehrsson, H Henrik; Ojemann, Jeffrey G

    2017-01-03

    Replacing the function of a missing or paralyzed limb with a prosthetic device that acts and feels like one's own limb is a major goal in applied neuroscience. Recent studies in nonhuman primates have shown that motor control and sensory feedback can be achieved by connecting sensors in a robotic arm to electrodes implanted in the brain. However, it remains unknown whether electrical brain stimulation can be used to create a sense of ownership of an artificial limb. In this study on two human subjects, we show that ownership of an artificial hand can be induced via the electrical stimulation of the hand section of the somatosensory (SI) cortex in synchrony with touches applied to a rubber hand. Importantly, the illusion was not elicited when the electrical stimulation was delivered asynchronously or to a portion of the SI cortex representing a body part other than the hand, suggesting that multisensory integration according to basic spatial and temporal congruence rules is the underlying mechanism of the illusion. These findings show that the brain is capable of integrating "natural" visual input and direct cortical-somatosensory stimulation to create the multisensory perception that an artificial limb belongs to one's own body. Thus, they serve as a proof of concept that electrical brain stimulation can be used to "bypass" the peripheral nervous system to induce multisensory illusions and ownership of artificial body parts, which has important implications for patients who lack peripheral sensory input due to spinal cord or nerve lesions.

  12. Changes in the spectral composition of animal-brain electrical activity under the influence of nonthermal millimeter-wave radiation on acupuncture points

    Science.gov (United States)

    Khramov, R. N.; Vorob'ev, V. V.

    1994-01-01

    The frequency spectra (0 26 Hz) of electrograms (EG) of the preoptic region of the hypothalamus were studied in chronic experiments on nine awake rabbits under the influence of nonthermal millimeter-band (55 75 GHz) electromagnetic fields on various acupuncture points: I) the auricular “heart” point (after F. G. Portnov); II) the cranial acupoint (TR-20; the “hypothalamus” point after R. Voll); and III) the “longevity” acupoint (E-36). Irradiation of point I was accompanied by significant suppression of hypothalamic electrical activity at 5 and 16 Hz and enhancement at 7 8, 12, and 26 Hz. Irradiation of point II had similar but less-prominent effects at 7 8 and 12 Hz. Minimal EG changes were observed with exposure of point III. The probabilities of significant changes in EG spectra for irradiation of points I, II, and III were, respectively, 31%, 21%, and 5% (pacupuncture points I and II are more sensitive to millimeter-band radiation than is point III. The presence of individual characteristics of the effects and their change after stress to sign inversion were shown in rat experiments in which the acupuncture points were irradiated.

  13. Changes in the spectral composition of animal-brain electrical activity under the influence of nonthermal millimeter-wave radiation on acupuncture points

    Energy Technology Data Exchange (ETDEWEB)

    Khramov, R.N.; Vorob`ev, V.V.

    1994-07-01

    The frequency spectra (0-26 Hz) of electrograms (EG) of the preoptic region of the hypothalamus were studied in chronic experiments on nine awake rabbits under the influence of nonthermal millimeter-bank (55-75 GHz) electromagnetic fields on various acupuncture points: (I) the auricular {open_quotes}heart{close_quotes} point (after F. G. Portnov); (II) the cranial acupoint (TR-20; the {open_quotes}hypothalamus{close_quotes} point after R. Voll); and (III) the {open_quotes}longevity{close_quotes} acupoint (E-36). Irradiation of point I was accompanied by significant suppression of hypothalamic electrical activity at 5 and 16 Hz and enhancement at 7-8, 12, and 26 Hz. Irradiation of point II, and III were, respectively, 31%, 21%, and 5% (p < 0.05, U-criterion). These results suggest that acupuncture points I and II are more sensitive to millimeter-band radiation than is point III. The presence of individual characteristics of the effects and their change after stress to sign inversion were shown in rat experiments in which the acupuncture points were irradiated.

  14. Measurements and models of electric fields in the in vivo human brain during transcranial electric stimulation.

    Science.gov (United States)

    Huang, Yu; Liu, Anli A; Lafon, Belen; Friedman, Daniel; Dayan, Michael; Wang, Xiuyuan; Bikson, Marom; Doyle, Werner K; Devinsky, Orrin; Parra, Lucas C

    2017-02-07

    Transcranial electric stimulation aims to stimulate the brain by applying weak electrical currents at the scalp. However, the magnitude and spatial distribution of electric fields in the human brain are unknown. We measured electric potentials intracranially in ten epilepsy patients and estimated electric fields across the entire brain by leveraging calibrated current-flow models. When stimulating at 2 mA, cortical electric fields reach 0.4 V/m, the lower limit of effectiveness in animal studies. When individual whole-head anatomy is considered, the predicted electric field magnitudes correlate with the recorded values in cortical (r = 0.89) and depth (r = 0.84) electrodes. Accurate models require adjustment of tissue conductivity values reported in the literature, but accuracy is not improved when incorporating white matter anisotropy or different skull compartments. This is the first study to validate and calibrate current-flow models with in vivo intracranial recordings in humans, providing a solid foundation to target stimulation and interpret clinical trials.

  15. Brain evolution triggers increased diversification of electric fishes.

    Science.gov (United States)

    Carlson, Bruce A; Hasan, Saad M; Hollmann, Michael; Miller, Derek B; Harmon, Luke J; Arnegard, Matthew E

    2011-04-29

    Communication can contribute to the evolution of biodiversity by promoting speciation and reinforcing reproductive isolation between existing species. The evolution of species-specific signals depends on the ability of individuals to detect signal variation, which in turn relies on the capability of the brain to process signal information. Here, we show that evolutionary change in a region of the brain devoted to the analysis of communication signals in mormyrid electric fishes improved detection of subtle signal variation and resulted in enhanced rates of signal evolution and species diversification. These results show that neural innovations can drive the diversification of signals and promote speciation.

  16. Multi-Scale Computational Models for Electrical Brain Stimulation

    Science.gov (United States)

    Seo, Hyeon; Jun, Sung C.

    2017-01-01

    Electrical brain stimulation (EBS) is an appealing method to treat neurological disorders. To achieve optimal stimulation effects and a better understanding of the underlying brain mechanisms, neuroscientists have proposed computational modeling studies for a decade. Recently, multi-scale models that combine a volume conductor head model and multi-compartmental models of cortical neurons have been developed to predict stimulation effects on the macroscopic and microscopic levels more precisely. As the need for better computational models continues to increase, we overview here recent multi-scale modeling studies; we focused on approaches that coupled a simplified or high-resolution volume conductor head model and multi-compartmental models of cortical neurons, and constructed realistic fiber models using diffusion tensor imaging (DTI). Further implications for achieving better precision in estimating cellular responses are discussed. PMID:29123476

  17. [Comparative study on effects of electroacupuncture stimulation of Shenmen (HT 7) and Taiyuan (LU 9) on P 300 of event-related potentials and brain electrical activity mapping in healthy young adults].

    Science.gov (United States)

    Hu, Wu-Bin; Hu, Ling; Dong, Chao-Yang; Cai, Rong-Lin; Zhou, Yi-Ping; Wang, Ke-Ming; Zhang, Cheng; Zhou, Feng

    2013-06-01

    To observe the effect difference of electroacupuncture (EA) stimulation of Shenmen (HT 7) and Taiyuan (LU 9) on P 300 of event-related potentials (ERPs) in volunteer subjects, so as to explore functional specificity of acupoints in processing cerebral information. Sixty healthy volunteer college students were randomly and equally divided into Shenmen (HT 7) group and Taiyuan (LU 9) group (30 persons/group). EA (2 Hz, 1 mA) was applied to bilateral Shenmen (HT 7) and Taiyuan (LU 9) for 15 min. The ERPs were acquired by averaging EEG activity following Oddba II auditory tone-double stimuli and brain electrical activity mapping (BEAM) acquired by means of Scan 4.5 collection and analysis system. Data were calculated and analyzed with SPSS 17.0 for Windows. After testing, the subjects were inquired about the perception for acupuncture stimulation and other sensations or psychological activities. Following EA stimulation of both HT 7 and LU 9, the amplitude of P 300 in the ERPs were significantly decreased in comparison with pre-EA stimulation in the same one group (P 0.05). But, EA of HT 7 had a slightly stronger effect in shortening P 300 latency. With regard to the potential intensity distribution of BEAM, there were some differences between HT 7 and LU 9 groups. The high potential responses for HT 7 were found mainly in the occipital lobe, and in the left parietal lobe and the right temporal lobe, whereas those for LU 9 were found to mainly disperse in the left occipital lobe and the parietal lobe. EA stimulation of HT 7 and LU 9 has a slight difference on lowering P 300 amplitude of ERPs, and may result in different distribution of the high potential responses in different lobes of the cerebral cortex in healthy subjects. The functional specificity of EA stimulation of different acupoints needs further study.

  18. Electrical stunning and exsanguination decrease the extracellular volume in the broiler brain as studied with brain impedance recordings

    NARCIS (Netherlands)

    Savenije, B; Lambooij, E; Pieterse, C; Korf, J

    Electrical stunning in the process of slaughtering poultry is used to induce unconsciousness and immobilize the animal for easier processing. Unconsciousness is a function of brain damage. Brain damage has been studied with brain impedance recordings under ischemic conditions. This experiment

  19. Electricity and Magnetism: Insights into the brain from multimodal imaging.

    Science.gov (United States)

    Cohen, M S

    2009-11-01

    The windows into brain function given us by the instruments of neuroimaging each are murky and their view is limited. Simultaneous collection of data from multiple modalities offers the potential to overcome the weaknesses of any tool alone. We argue that the combination of electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) offers observations - and hypothesis testing - not possible using either single instrument. Because of their safety profiles and their non-invasive natures, EEG fMRI are among the best available devices for the study of human brain. These methods are complementary. EEG is fast, operating in a time domain comparable to single unit activity, but its localizing power is poor and the field of view is limited. While fMRI has the highest spatial resolution of any noninvasive imaging method and can reveal multiple centers of brain activity implicated in cognitive tasks, it is very slow compared to mental activity and is a poor choice for studying rapidly evolving processes. Here, we address theoretical models of the coupling between EEG and fMRI signals based on cellular physiology and energetics and argue that both tools observe principally synaptic activity. We discuss the technical problems of mutual interference then present several models of brain rhythms for which the joint EEG and fMRI observations provide significant evidence.

  20. Alterations of brain activity in fibromyalgia patients.

    Science.gov (United States)

    Sawaddiruk, Passakorn; Paiboonworachat, Sahattaya; Chattipakorn, Nipon; Chattipakorn, Siriporn C

    2017-04-01

    Fibromyalgia is a chronic pain syndrome, characterized by widespread musculoskeletal pain with diffuse tenderness at multiple tender points. Despite intense investigations, the pathophysiology of fibromyalgia remains elusive. Evidence shows that it could be due to changes in either the peripheral or central nervous system (CNS). For the CNS changes, alterations in the high brain area of fibromyalgia patients have been investigated but the definite mechanisms are still unclear. Magnetic Resonance Imaging (MRI) and Functional Magnetic Resonance (fMRI) have been used to gather evidence regarding the changes of brain morphologies and activities in fibromyalgia patients. Nevertheless, due to few studies, limited knowledge for alterations in brain activities in fibromyalgia is currently available. In this review, the changes in brain activity in various brain areas obtained from reports in fibromyalgia patients are comprehensively summarized. Changes of the grey matter in multiple regions such as the superior temporal gyrus, posterior thalamus, amygdala, basal ganglia, cerebellum, cingulate cortex, SII, caudate and putamen from the MRI as well as the increase of brain activities in the cerebellum, prefrontal cortex, anterior cingulate cortex, thalamus, somatosensory cortex, insula in fMRI studies are presented and discussed. Moreover, evidence from pharmacological interventions offering benefits for fibromyalgia patients by reducing brain activity is presented. Because of limited knowledge regarding the roles of brain activity alterations in fibromyalgia, this summarized review will encourage more future studies to elucidate the underlying mechanisms involved in the brains of these patients. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Mapping brain activity with flexible graphene micro-transistors

    CERN Document Server

    Blaschke, Benno M; Guimerà-Brunet, Anton; Weinert, Julia; Rousseau, Lionel; Heimann, Axel; Drieschner, Simon; Kempski, Oliver; Villa, Rosa; Sanchez-Vives, Maria V; Garrido, Jose A

    2016-01-01

    Establishing a reliable communication interface between the brain and electronic devices is of paramount importance for exploiting the full potential of neural prostheses. Current microelectrode technologies for recording electrical activity, however, evidence important shortcomings, e.g. challenging high density integration. Solution-gated field-effect transistors (SGFETs), on the other hand, could overcome these shortcomings if a suitable transistor material were available. Graphene is particularly attractive due to its biocompatibility, chemical stability, flexibility, low intrinsic electronic noise and high charge carrier mobilities. Here, we report on the use of an array of flexible graphene SGFETs for recording spontaneous slow waves, as well as visually evoked and also pre-epileptic activity in vivo in rats. The flexible array of graphene SGFETs allows mapping brain electrical activity with excellent signal-to-noise ratio (SNR), suggesting that this technology could lay the foundation for a future gene...

  2. Mapping brain activity with flexible graphene micro-transistors

    Science.gov (United States)

    Blaschke, Benno M.; Tort-Colet, Núria; Guimerà-Brunet, Anton; Weinert, Julia; Rousseau, Lionel; Heimann, Axel; Drieschner, Simon; Kempski, Oliver; Villa, Rosa; Sanchez-Vives, Maria V.; Garrido, Jose A.

    2017-06-01

    Establishing a reliable communication interface between the brain and electronic devices is of paramount importance for exploiting the full potential of neural prostheses. Current microelectrode technologies for recording electrical activity, however, evidence important shortcomings, e.g. challenging high density integration. Solution-gated field-effect transistors (SGFETs), on the other hand, could overcome these shortcomings if a suitable transistor material were available. Graphene is particularly attractive due to its biocompatibility, chemical stability, flexibility, low intrinsic electronic noise and high charge carrier mobilities. Here, we report on the use of an array of flexible graphene SGFETs for recording spontaneous slow waves, as well as visually evoked and also pre-epileptic activity in vivo in rats. The flexible array of graphene SGFETs allows mapping brain electrical activity with excellent signal-to-noise ratio (SNR), suggesting that this technology could lay the foundation for a future generation of in vivo recording implants.

  3. Electric Field Activated Shape Memory Polymer Composite

    Science.gov (United States)

    Kang, Jin Ho (Inventor); Siochi, Emilie J. (Inventor); Penner, Ronald K. (Inventor); Turner, Travis L. (Inventor)

    2017-01-01

    Provided is an electrically activated shape memory polymer composite capable of thermal shape reformation using electric power to heat the composite through its matrix glass transition temperature. The composite includes an adaptable polymer matrix component using a diglycidyl ether resin, at least one substantially well-dispersed conductive or magnetic nano-filler component, and at least one elastic, laminated layer. Also provided are methods of preparing the composite and methods of activating the composite. A shape reformation of the composite is triggered by applying an electric field at DC and/or at a frequency above about 1.mu.Hz for a sufficient time.

  4. Effect of electrical vs. chemical deep brain stimulation at midbrain sites on micturition in anaesthetized rats.

    Science.gov (United States)

    Stone, E; Coote, J H; Lovick, T A

    2015-05-01

    To understand how deep brain stimulation of the midbrain influences control of the urinary bladder. In urethane-anaesthetized male rats, saline was infused continuously into the bladder to evoke cycles of filling and voiding. The effect of electrical (0.1-2.0 ms pulses, 5-180 Hz, 0.5-2.5 V) compared to chemical stimulation (microinjection of D,L-homocysteic acid, 50 nL 0.1 M solution) at the same midbrain sites was tested. Electrical stimulation of the periaqueductal grey matter and surrounding midbrain disrupted normal coordinated voiding activity in detrusor and sphincters muscles and suppressed urine output. The effect occurred within seconds was reversible and not secondary to cardiorespiratory changes. Bladder compliance remained unchanged. Chemical stimulation over the same area using microinjection of D,L-homocysteic acid (DLH) to preferentially activate somatodendritic receptors decreased the frequency of micturition but did not disrupt the coordinated pattern of voiding. In contrast, chemical stimulation within the caudal ventrolateral periaqueductal grey, in the area where critical synapses in the micturition reflex pathway are located, increased the frequency of micturition. Electrical deep brain stimulation within the midbrain can inhibit reflex micturition. We suggest that the applied stimulus entrained activity in the neural circuitry locally, thereby imposing an unphysiological pattern of activity. In a way similar to the use of electrical signals to 'jam' radio transmission, this may prevent a synchronized pattern of efferent activity being transmitted to the spinal outflows to orchestrate a coordinated voiding response. Further experiments to record neuronal firing in the midbrain during the deep brain stimulation will be necessary to test this hypothesis. © 2015 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

  5. The Physical Brain: New Approaches to Brain Structure, Activity, and Function

    Science.gov (United States)

    Robinson, P. A.

    By viewing the brain as a multiscale physical system it is possible to circumvent the shortcomings of abstract signal-based and statistical approaches to analysis of brain structure, activity, and function. Eigenmode approaches enable the key elements of brain structure to be isolated systematically, along with their effects on brain activity and functional measures. Physiologically-based neural field theory permits tractable analysis from sub-mm scales to the whole brain, demonstrating the near-critical state of normal brain operation, relationships between structure and function, nonlinear dynamics, and phase transitions. Results in normal and abnormal states include experimentally verified predictions of electrical and hemodynamic signals, and the successful inversion of functional correlation measures to infer underlying brain structure, including connectivities that cannot be measured directly. These results illustrate the power of physically based modeling to predict, explain, and unify multiple observations across scales. Furthermore, they open up ways to expand the field of biological physics and apply it to a host of new phenomena. Australian Research Council, Grants FL1401000225 and CE140100007.

  6. An improved ivermectin-activated chloride channel receptor for inhibiting electrical activity in defined neuronal populations

    DEFF Research Database (Denmark)

    Lynagh, Timothy Peter; Lynch, Joseph W

    2010-01-01

    The ability to silence the electrical activity of defined neuronal populations in vivo is dramatically advancing our understanding of brain function. This technology may eventually be useful clinically for treating a variety of neuropathological disorders caused by excessive neuronal activity...... for surgically implanted stimulus delivery methods and their use of nonhuman receptors. A third silencing method, an invertebrate glutamate-gated chloride channel receptor (GluClR) activated by ivermectin, solves the stimulus delivery problem as ivermectin is a safe, well tolerated drug that reaches the brain...

  7. Electric field distribution in a finite-volume head model of deep brain stimulation.

    Science.gov (United States)

    Grant, Peadar F; Lowery, Madeleine M

    2009-11-01

    This study presents a whole-head finite element model of deep brain stimulation to examine the effect of electrical grounding, the finite conducting volume of the head, and scalp, skull and cerebrospinal fluid layers. The impedance between the stimulating and reference electrodes in the whole-head model was found to lie within clinically reported values when the reference electrode was incorporated on a localized surface in the model. Incorporation of the finite volume of the head and inclusion of surrounding outer tissue layers reduced the magnitude of the electric field and activating function by approximately 20% in the region surrounding the electrode. Localized distortions of the electric field were also observed when the electrode was placed close to the skull. Under bipolar conditions the effect of the finite conducting volume was shown to be negligible. The results indicate that, for monopolar stimulation, incorporation of the finite volume and outer tissue layers can alter the magnitude of the electric field and activating function when the electrode is deep within the brain, and may further affect the shape if the electrode is close to the skull.

  8. Active Electrical-Transient Damper

    Science.gov (United States)

    Dolland, Carlisle R.

    1992-01-01

    Active damping circuit functions similarly to passive damping circuit, but volume, weight, and cost do not increase as steeply with rated power as equivalent passive damper. Affords advantages of economy that increases with rated power.

  9. Active tactile exploration using a brain-machine-brain interface.

    Science.gov (United States)

    O'Doherty, Joseph E; Lebedev, Mikhail A; Ifft, Peter J; Zhuang, Katie Z; Shokur, Solaiman; Bleuler, Hannes; Nicolelis, Miguel A L

    2011-10-05

    Brain-machine interfaces use neuronal activity recorded from the brain to establish direct communication with external actuators, such as prosthetic arms. It is hoped that brain-machine interfaces can be used to restore the normal sensorimotor functions of the limbs, but so far they have lacked tactile sensation. Here we report the operation of a brain-machine-brain interface (BMBI) that both controls the exploratory reaching movements of an actuator and allows signalling of artificial tactile feedback through intracortical microstimulation (ICMS) of the primary somatosensory cortex. Monkeys performed an active exploration task in which an actuator (a computer cursor or a virtual-reality arm) was moved using a BMBI that derived motor commands from neuronal ensemble activity recorded in the primary motor cortex. ICMS feedback occurred whenever the actuator touched virtual objects. Temporal patterns of ICMS encoded the artificial tactile properties of each object. Neuronal recordings and ICMS epochs were temporally multiplexed to avoid interference. Two monkeys operated this BMBI to search for and distinguish one of three visually identical objects, using the virtual-reality arm to identify the unique artificial texture associated with each. These results suggest that clinical motor neuroprostheses might benefit from the addition of ICMS feedback to generate artificial somatic perceptions associated with mechanical, robotic or even virtual prostheses.

  10. Low-frequency dielectric dispersion of brain tissue due to electrically long neurites

    Science.gov (United States)

    Monai, Hiromu; Inoue, Masashi; Miyakawa, Hiroyoshi; Aonishi, Toru

    2012-12-01

    The dielectric properties of brain tissue are important for understanding how neural activity is related to local field potentials and electroencephalograms. It is known that the permittivity of brain tissue exhibits strong frequency dependence (dispersion) and that the permittivity is very large in the low-frequency region. However, little is known with regard to the cause of the large permittivity in the low-frequency region. Here, we postulate that the dielectric properties of brain tissue can be partially accounted for by assuming that neurites are of sufficient length to be “electrically long.” To test this idea, we consider a model in which a neurite is treated as a long, narrow body, and it is subjected to a stimulus created by electrodes situated in the region external to it. With regard to this electric stimulus, the neurite can be treated as a passive cable. Assuming adequate symmetry so that the tissue packed with multiple cables is equivalent to an isolated system consisting of a single cable and a surrounding extracellular resistive medium, we analytically calculate the extracellular potential of the tissue in response to such an externally created alternating-current electric field using a Green's function that we obtained previously. Our results show that brain tissue modeled by such a cable existing within a purely resistive extracellular medium exhibits a large effective permittivity in the low-frequency region. Moreover, we obtain results suggesting that an extremely large low-frequency permittivity can coexist with weak low-pass filter characteristics in brain tissue.

  11. Using perturbations to identify the brain circuits underlying active vision.

    Science.gov (United States)

    Wurtz, Robert H

    2015-09-19

    The visual and oculomotor systems in the brain have been studied extensively in the primate. Together, they can be regarded as a single brain system that underlies active vision--the normal vision that begins with visual processing in the retina and extends through the brain to the generation of eye movement by the brainstem. The system is probably one of the most thoroughly studied brain systems in the primate, and it offers an ideal opportunity to evaluate the advantages and disadvantages of the series of perturbation techniques that have been used to study it. The perturbations have been critical in moving from correlations between neuronal activity and behaviour closer to a causal relation between neuronal activity and behaviour. The same perturbation techniques have also been used to tease out neuronal circuits that are related to active vision that in turn are driving behaviour. The evolution of perturbation techniques includes ablation of both cortical and subcortical targets, punctate chemical lesions, reversible inactivations, electrical stimulation, and finally the expanding optogenetic techniques. The evolution of perturbation techniques has supported progressively stronger conclusions about what neuronal circuits in the brain underlie active vision and how the circuits themselves might be organized.

  12. Mimicking muscle activity with electrical stimulation

    Science.gov (United States)

    Johnson, Lise A.; Fuglevand, Andrew J.

    2011-02-01

    Functional electrical stimulation is a rehabilitation technology that can restore some degree of motor function in individuals who have sustained a spinal cord injury or stroke. One way to identify the spatio-temporal patterns of muscle stimulation needed to elicit complex upper limb movements is to use electromyographic (EMG) activity recorded from able-bodied subjects as a template for electrical stimulation. However, this requires a transfer function to convert the recorded (or predicted) EMG signals into an appropriate pattern of electrical stimulation. Here we develop a generalized transfer function that maps EMG activity into a stimulation pattern that modulates muscle output by varying both the pulse frequency and the pulse amplitude. We show that the stimulation patterns produced by this transfer function mimic the active state measured by EMG insofar as they reproduce with good fidelity the complex patterns of joint torque and joint displacement.

  13. Subthalamic nucleus electrical stimulation modulates calcium activity of nigral astrocytes.

    Directory of Open Access Journals (Sweden)

    Elodie Barat

    Full Text Available BACKGROUND: The substantia nigra pars reticulata (SNr is a major output nucleus of the basal ganglia, delivering inhibitory efferents to the relay nuclei of the thalamus. Pathological hyperactivity of SNr neurons is known to be responsible for some motor disorders e.g. in Parkinson's disease. One way to restore this pathological activity is to electrically stimulate one of the SNr input, the excitatory subthalamic nucleus (STN, which has emerged as an effective treatment for parkinsonian patients. The neuronal network and signal processing of the basal ganglia are well known but, paradoxically, the role of astrocytes in the regulation of SNr activity has never been studied. PRINCIPAL FINDINGS: In this work, we developed a rat brain slice model to study the influence of spontaneous and induced excitability of afferent nuclei on SNr astrocytes calcium activity. Astrocytes represent the main cellular population in the SNr and display spontaneous calcium activities in basal conditions. Half of this activity is autonomous (i.e. independent of synaptic activity while the other half is dependent on spontaneous glutamate and GABA release, probably controlled by the pace-maker activity of the pallido-nigral and subthalamo-nigral loops. Modification of the activity of the loops by STN electrical stimulation disrupted this astrocytic calcium excitability through an increase of glutamate and GABA releases. Astrocytic AMPA, mGlu and GABA(A receptors were involved in this effect. SIGNIFICANCE: Astrocytes are now viewed as active components of neural networks but their role depends on the brain structure concerned. In the SNr, evoked activity prevails and autonomous calcium activity is lower than in the cortex or hippocampus. Our data therefore reflect a specific role of SNr astrocytes in sensing the STN-GPe-SNr loops activity and suggest that SNr astrocytes could potentially feedback on SNr neuronal activity. These findings have major implications given the

  14. Measuring thrombin activity in frozen brain tissue.

    Science.gov (United States)

    Reuveni, Gilad; Golderman, Valery; Shavit-Stein, Efrat; Rosman, Yossi; Shrot, Shai; Chapman, Joab; Harnof, Sagi

    2017-12-06

    Thrombin is a coagulation factor implicated in various pathological and physiological processes in the brain, exerting beneficial and deleterious effects in a concentration-dependent manner. Measurement of thrombin activity levels in pathological animal models is needed and in some cases, because of technical considerations, only frozen samples are available. In the current study, we used a quantitative method to evaluate thrombin activity in fresh and frozen brain sections of 43 male and female adult healthy mice. We stratified data per brain section, brain hemisphere, and mouse sex. We found lower thrombin activity in frozen sections compared with fresh sections, falling within levels considered central nervous system protective in previous studies. The results suggest that fresh section thrombin activity levels in healthy mice can be extrapolated from frozen brain sections. In addition, we found varying thrombin activity across the brain sections, with maximal activity in the olfactory system and hippocampus-containing sections. Thrombin activity did not vary between males and females, or between the right and the left hemispheres, in a statistically significantly manner.

  15. A brain-specific transcription activator.

    Science.gov (United States)

    Korner, M; Rattner, A; Mauxion, F; Sen, R; Citri, Y

    1989-11-01

    We have identified a DNA binding protein, named BETA, that interacts with the same (B) transcriptional regulatory sequence as the known transcription factor NF-kappa B. BETA is found only in gray matter throughout the brain, and not in a variety of other rat tissues. Two binding sites for BETA are present adjacent to the promoter of the rat proenkephalin gene. Transfection of primary brain cultures that express BETA, with a reporter gene driven by the SV40 promoter linked to BETA DNA binding sites, results in transcriptional activation. We infer that BETA is a brain-specific transcription activator.

  16. The morphological and molecular changes of brain cells exposed to direct current electric field stimulation.

    Science.gov (United States)

    Pelletier, Simon J; Lagacé, Marie; St-Amour, Isabelle; Arsenault, Dany; Cisbani, Giulia; Chabrat, Audrey; Fecteau, Shirley; Lévesque, Martin; Cicchetti, Francesca

    2014-12-07

    The application of low-intensity direct current electric fields has been experimentally used in the clinic to treat a number of brain disorders, predominantly using transcranial direct current stimulation approaches. However, the cellular and molecular changes induced by such treatment remain largely unknown. Here, we tested various intensities of direct current electric fields (0, 25, 50, and 100V/m) in a well-controlled in vitro environment in order to investigate the responses of neurons, microglia, and astrocytes to this type of stimulation. This included morphological assessments of the cells, viability, as well as shape and fiber outgrowth relative to the orientation of the direct current electric field. We also undertook enzyme-linked immunosorbent assays and western immunoblotting to identify which molecular pathways were affected by direct current electric fields. In response to direct current electric field, neurons developed an elongated cell body shape with neurite outgrowth that was associated with a significant increase in growth associated protein-43. Fetal midbrain dopaminergic explants grown in a collagen gel matrix also showed a reorientation of their neurites towards the cathode. BV2 microglial cells adopted distinct morphological changes with an increase in cyclooxygenase-2 expression, but these were dependent on whether they had already been activated with lipopolysaccharide. Finally, astrocytes displayed elongated cell bodies with cellular filopodia that were oriented perpendicularly to the direct current electric field. We show that cells of the central nervous system can respond to direct current electric fields both in terms of their morphological shape and molecular expression of certain proteins, and this in turn can help us to begin understand the mechanisms underlying the clinical benefits of direct current electric field. © The Author 2015. Published by Oxford University Press on behalf of CINP.

  17. Does Aerobic Exercise Influence Intrinsic Brain Activity?

    DEFF Research Database (Denmark)

    Flodin, Pär; Jonasson, Lars S; Riklund, Katrin

    2017-01-01

    . At baseline, VO2-peak was negativly related to BOLD-signal fluctuations (BOLDSTD) in mid temporal areas. Over 6 months, improvements in aerobic capacity were associated with decreased connectivity between left hippocampus and contralateral precentral gyrus, and positively to connectivity between right mid......Previous studies have indicated that aerobic exercise could reduce age related decline in cognition and brain functioning. Here we investigated the effects of aerobic exercise on intrinsic brain activity. Sixty sedentary healthy males and females (64-78 years) were randomized into either an aerobic...... exercise group or an active control group. Both groups recieved supervised training, 3 days a week for 6 months. Multimodal brain imaging data was acquired before and after the intervention, including 10 min of resting state brain functional magnetic resonance imaging (rs-fMRI) and arterial spin labeling...

  18. Heritability of working memory brain activation.

    Science.gov (United States)

    Blokland, Gabriëlla A M; McMahon, Katie L; Thompson, Paul M; Martin, Nicholas G; de Zubicaray, Greig I; Wright, Margaret J

    2011-07-27

    Although key to understanding individual variation in task-related brain activation, the genetic contribution to these individual differences remains largely unknown. Here we report voxel-by-voxel genetic model fitting in a large sample of 319 healthy, young adult, human identical and fraternal twins (mean ± SD age, 23.6 ± 1.8 years) who performed an n-back working memory task during functional magnetic resonance imaging (fMRI) at a high magnetic field (4 tesla). Patterns of task-related brain response (BOLD signal difference of 2-back minus 0-back) were significantly heritable, with the highest estimates (40-65%) in the inferior, middle, and superior frontal gyri, left supplementary motor area, precentral and postcentral gyri, middle cingulate cortex, superior medial gyrus, angular gyrus, superior parietal lobule, including precuneus, and superior occipital gyri. Furthermore, high test-retest reliability for a subsample of 40 twins indicates that nongenetic variance in the fMRI brain response is largely due to unique environmental influences rather than measurement error. Individual variations in activation of the working memory network are therefore significantly influenced by genetic factors. By establishing the heritability of cognitive brain function in a large sample that affords good statistical power, and using voxel-by-voxel analyses, this study provides the necessary evidence for task-related brain activation to be considered as an endophenotype for psychiatric or neurological disorders, and represents a substantial new contribution to the field of neuroimaging genetics. These genetic brain maps should facilitate discovery of gene variants influencing cognitive brain function through genome-wide association studies, potentially opening up new avenues in the treatment of brain disorders.

  19. Core networks for visual-concrete and abstract thought content: a brain electric microstate analysis.

    Science.gov (United States)

    Lehmann, Dietrich; Pascual-Marqui, Roberto D; Strik, Werner K; Koenig, Thomas

    2010-01-01

    Commonality of activation of spontaneously forming and stimulus-induced mental representations is an often made but rarely tested assumption in neuroscience. In a conjunction analysis of two earlier studies, brain electric activity during visual-concrete and abstract thoughts was studied. The conditions were: in study 1, spontaneous stimulus-independent thinking (post-hoc, visual imagery or abstract thought were identified); in study 2, reading of single nouns ranking high or low on a visual imagery scale. In both studies, subjects' tasks were similar: when prompted, they had to recall the last thought (study 1) or the last word (study 2). In both studies, subjects had no instruction to classify or to visually imagine their thoughts, and accordingly were not aware of the studies' aim. Brain electric data were analyzed into functional topographic brain images (using LORETA) of the last microstate before the prompt (study 1) and of the word-type discriminating event-related microstate after word onset (study 2). Conjunction analysis across the two studies yielded commonality of activation of core networks for abstract thought content in left anterior superior regions, and for visual-concrete thought content in right temporal-posterior inferior regions. The results suggest that two different core networks are automatedly activated when abstract or visual-concrete information, respectively, enters working memory, without a subject task or instruction about the two classes of information, and regardless of internal or external origin, and of input modality. These core machineries of working memory thus are invariant to source or modality of input when treating the two types of information.

  20. Electrical Activity in Martian Dust Storms

    Science.gov (United States)

    Majid, W.; Arabshahi, S.; Kocz, J.

    2016-12-01

    Dust storms on Mars are predicted to be capable of producing electrostatic fields and discharges, even larger than those in dust storms on Earth. Such electrical activity poses serious risks to any Human exploration of the planet and the lack of sufficient data to characterize any such activity has been identified by NASA's MEPAG as a key human safety knowledge gap. There are three key elements in the characterization of Martian electrostatic discharges: dependence on Martian environmental conditions, frequency of occurrence, and the strength of the generated electric fields. We will describe a recently deployed detection engine using NASA's Deep Space Network (DSN) to carry out a long term monitoring campaign to search for and characterize the entire Mars hemisphere for powerful discharges during routine tracking of spacecraft at Mars on an entirely non-interfering basis. The resulting knowledge of Mars electrical activity would allow NASA to plan risk mitigation measures to ensure human safety during Mars exploration. In addition, these measurements will also allow us to place limits on presence of oxidants such as H2O2 that may be produced by such discharges, providing another measurement point for models describing Martian atmospheric chemistry and habitability. Because of the continuous Mars telecommunication needs of NASA's Mars-based assets, the DSN is the only instrument in the world that combines long term, high cadence, observing opportunities with large sensitive telescopes, making it a unique asset worldwide in searching for and characterizing electrostatic activity at Mars from the ground.

  1. A device for long-term perfusion, imaging, and electrical interfacing of brain tissue in vitro

    Directory of Open Access Journals (Sweden)

    Nathaniel J Killian

    2016-03-01

    Full Text Available Distributed microelectrode array (MEA recordings from consistent, viable, ≥ 500 µm thick tissue preparations over time periods from days to weeks may aid in studying a wide range of problems in neurobiology that require in vivo-like organotypic morphology. Existing tools for electrically interfacing with organotypic slices do not address necrosis that inevitably occurs within thick slices with limited diffusion of nutrients and gas, and limited removal of waste. We developed an integrated device that enables long-term maintenance of thick, functionally active, brain tissue models using interstitial perfusion and distributed recordings from thick sections of explanted tissue on a perforated multi-electrode array. This novel device allows for automated culturing, in situ imaging, and extracellular multi-electrode interfacing with brain slices, 3 D cell cultures, and potentially other tissue culture models. The device is economical, easy to assemble, and integrable with standard electrophysiology tools. We found that convective perfusion through the culture thickness provided a functional benefit to the preparations as firing rates were generally higher in perfused cultures compared to their respective unperfused controls. This work is a step towards the development of integrated tools for days-long experiments with more consistent, healthier, thicker, and functionally more active tissue cultures with built-in distributed electrophysiological recording and stimulation functionality. The results may be useful for the study of normal processes, pathological conditions, and drug screening strategies currently hindered by the limitations of acute (a few hours long brain slice preparations.

  2. Inhibition of brain tumor cell proliferation by alternating electric fields

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Hyesun; Oh, Seung-ick; Hong, Sunghoi, E-mail: shong21@korea.ac.kr, E-mail: radioyoon@korea.ac.kr [School of Biosystem and Biomedical Science, Korea University, Seoul 136-703 (Korea, Republic of); Sung, Jiwon; Jeong, Seonghoon; Yoon, Myonggeun, E-mail: shong21@korea.ac.kr, E-mail: radioyoon@korea.ac.kr [Department of Bio-convergence Engineering, Korea University, Seoul 136-703 (Korea, Republic of); Koh, Eui Kwan [Seoul Center, Korea Basic Science Institute, Seoul 136-713 (Korea, Republic of)

    2014-11-17

    This study was designed to investigate the mechanism by which electric fields affect cell function, and to determine the optimal conditions for electric field inhibition of cancer cell proliferation. Low-intensity (<2 V/cm) and intermediate-frequency (100–300 kHz) alternating electric fields were applied to glioblastoma cell lines. These electric fields inhibited cell proliferation by inducing cell cycle arrest and abnormal mitosis due to the malformation of microtubules. These effects were significantly dependent on the intensity and frequency of applied electric fields.

  3. Brain activation during human male ejaculation revisited

    NARCIS (Netherlands)

    Georgiadis, Janniko R.; Reinders, A. A. T. Simone; Van der Graaf, Ferdinand H. C. E.; Paans, Anne M. J.; Kortekaas, Rudie

    2007-01-01

    In a prior [O-15]-H2O positron emission tomographic study we reported brain regions involved in human male ejaculation. Here, we used another, more recently acquired data set to evaluate the methodological approach of this previous study, and discovered that part of the reported activation pattern

  4. Electromagnetic imaging of dynamic brain activity

    Energy Technology Data Exchange (ETDEWEB)

    Mosher, J.; Leahy, R. [University of Southern California, Los Angeles, CA (United States). Dept. of Electrical Engineering; Lewis, P.; Lewine, J.; George, J. [Los Alamos National Lab., NM (United States); Singh, M. [University of Southern California, Los Angeles, CA (United States). Dept. of Radiology

    1991-12-31

    Neural activity in the brain produces weak dynamic electromagnetic fields that can be measured by an array of sensors. Using a spatio-temporal modeling framework, we have developed a new approach to localization of multiple neural sources. This approach is based on the MUSIC algorithm originally developed for estimating the direction of arrival of signals impinging on a sensor array. We present applications of this technique to magnetic field measurements of a phantom and of a human evoked somatosensory response. The results of the somatosensory localization are mapped onto the brain anatomy obtained from magnetic resonance images.

  5. Long-range correlations in rabbit brain neural activity.

    Science.gov (United States)

    de la Fuente, I M; Perez-Samartin, A L; Martínez, L; Garcia, M A; Vera-Lopez, A

    2006-02-01

    We have analyzed the presence of persistence properties in rabbit brain electrical signals by means of non-equilibrium statistical physics tools. To measure long-memory properties of these experimental signals, we have first determined whether the data are fractional Gaussian noise (fGn) or fractional Brownian motion (fBm) by calculating the slope of the power spectral density plot of the series. The results show that the series correspond to fBm. Then, the data were studied by means of the bridge detrended scaled windowed variance analysis, detecting long-term correlation. Three different types of experimental signals have been studied: neural basal activity without stimulation, the response induced by a single flash light stimulus and the average of the activity evoked by 200 flash light stimulations. Analysis of the series revealed the existence of persistent behavior in all cases. Moreover, the results also exhibited an increasing correlation in the level of long-term memory from recordings without stimulation, to one sweep recording or 200 sweeps averaged recordings. Thus, brain neural electrical activity is affected not only by its most recent states, but also by previous states much more distant in the past.

  6. Emerging subspecialties in neurology: deep brain stimulation and electrical neuro-network modulation.

    Science.gov (United States)

    Hassan, Anhar; Okun, Michael S

    2013-01-29

    Deep brain stimulation (DBS) is a surgical therapy that involves the delivery of an electrical current to one or more brain targets. This technology has been rapidly expanding to address movement, neuropsychiatric, and other disorders. The evolution of DBS has created a niche for neurologists, both in the operating room and in the clinic. Since DBS is not always deep, not always brain, and not always simply stimulation, a more accurate term for this field may be electrical neuro-network modulation (ENM). Fellowships will likely in future years evolve their scope to include other technologies, and other nervous system regions beyond typical DBS therapy.

  7. The restless brain: how intrinsic activity organizes brain function

    National Research Council Canada - National Science Library

    Raichle, Marcus E

    2015-01-01

    .... I suggest that the latter view best captures the essence of brain function, a position that accords well with the allocation of the brain's energy resources, its limited access to sensory information...

  8. A NOVEL METHOD FOR ANALYZING ELECTRIC FIELD DISTRIBUTION OF ELECTRO CAPACITIVE CANCER TREATMENT (ECCT USING WIRE MESH ELECTRODES: A CASE STUDY OF BRAIN CANCER THERAPY.

    Directory of Open Access Journals (Sweden)

    Linahtadiya Andiani

    2017-12-01

    Full Text Available Electric field distribution analysis generated by ECCT in a human head model with or without brain cancer using wire mesh electrode has been conductedsuccessfully. The analysis of electric field distribution was done using simulation in a human head model with ECCT Apparel Helmet system type A which is three dimensional model. The electric field distribution was measured with and without a wire mesh electrode which was either passive or active using COMSOL Multiphysics 5.2 software and was then processed using MATLAB R2010a. The aim of the research was to assess the performance of wire mesh electrode in detecting electric field distribution. ECCT which is utilized in brain cancer therapy with input 10 V is able to produce an electric field with an average of 178.8 V/m. The input voltage influences electric field distribution whereas the signal frequency does not affect the electric field distribution. Wire mesh electrode which is either active or passive can measure the electric field distribution generated by ECCT that neither the active nor the passive wire mesh electrode changed the pattern of the electric field distribution and the change in the measured electric field value is not significant.

  9. Enhancing Hebbian Learning to Control Brain Oscillatory Activity.

    Science.gov (United States)

    Soekadar, Surjo R; Witkowski, Matthias; Birbaumer, Niels; Cohen, Leonardo G

    2015-09-01

    Sensorimotor rhythms (SMR, 8-15 Hz) are brain oscillations associated with successful motor performance, imagery, and imitation. Voluntary modulation of SMR can be used to control brain-machine interfaces (BMI) in the absence of any physical movements. The mechanisms underlying acquisition of such skill are unknown. Here, we provide evidence for a causal link between function of the primary motor cortex (M1), active during motor skill learning and retention, and successful acquisition of abstract skills such as control over SMR. Thirty healthy participants were trained on 5 consecutive days to control SMR oscillations. Each participant was randomly assigned to one of 3 groups that received either 20 min of anodal, cathodal, or sham transcranial direct current stimulation (tDCS) over M1. Learning SMR control across training days was superior in the anodal tDCS group relative to the other 2. Cathodal tDCS blocked the beneficial effects of training, as evidenced with sham tDCS. One month later, the newly acquired skill remained superior in the anodal tDCS group. Thus, application of weak electric currents of opposite polarities over M1 differentially modulates learning SMR control, pointing to this primary cortical region as a common substrate for acquisition of physical motor skills and learning to control brain oscillatory activity. Published by Oxford University Press 2014. This work is written by (a) US Government employee(s) and is in the public domain in the US.

  10. Electromagnons: Electrically active spin excitations in multiferroics

    Science.gov (United States)

    Kamba, Stanislav; Goian, Veronica; Kadlec, Filip; Kadlec, Christelle; Vanek, Premysl; Kempa, Martin; Gich, Marti; Academy of Sciences of the Czech Republic Team; Institut de Ciència de Materials de Barcelona Team

    2014-03-01

    In some multiferroics spin wave can be excited by electric component of elmg. radiation and such excitations activated by dynamic magnetoelectric coupling are called electromagnons. We will discuss mechanism of electromagnon activation in the THz spectra of three different compounds: In the multiferroic TbMnO3, the ferroelectricity is induced by inverse Dzyaloshinskii-Moriya interaction, but two electromagnons are activated by the magnetostriction. Second example is CaMn7O12, whose polarization is the highest among all spin-induced ferroelectrics. In this material we observed three electromagnons, whose frequencies correspond to maxima of magnon density of states, so they should correspond to magnons from Brillouin zone boundary. Finally we will demonstrate that electromagnons are not limited to spin-induced ferroelectrics. We have observed an electromagnon in nanograin ceramics of epsilon-Fe2O3. This material is below 490 K a pyroelectric ferrimagnet and the electromagnon activates in the THz spectra only below 110 K, when the magnetic structure becomes incommensurately modulated. We will show how by combining infrared, THz and inelastic neutron scattering experiments, the electromagnons can be discerned from magnons or phonons. Performed all measurements.

  11. Influence of denture treatment on brain function activity

    Directory of Open Access Journals (Sweden)

    Toshio Hosoi

    2011-02-01

    In this study, it was revealed that brain function activity was enhanced by the improvement of complete dentures, and by wearing partial dentures. Not only denture function improvement but also brain functional activation was achieved in elderly denture wearers at risk of brain activity deterioration.

  12. Managing Brain Extracellular K(+) during Neuronal Activity

    DEFF Research Database (Denmark)

    Larsen, Brian Roland; Stoica, Anca; MacAulay, Nanna

    2016-01-01

    isoform compositions of the Na(+)/K(+)-ATPase remain unresolved. The various cell types in the brain serve a certain temporal contribution in the face of network activity; astrocytes respond directly to the immediate release of K(+) from neurons, whereas the neurons themselves become the primary K...... characteristics required to fulfill their distinct physiological roles in clearance of K(+) from the extracellular space in the face of neuronal activity. Understanding the nature, impact and effects of the various Na(+)/K(+)-ATPase isoform combinations in K(+) management in the central nervous system might...

  13. Broadband active electrically small superconductor antennas

    Science.gov (United States)

    Kornev, V. K.; Kolotinskiy, N. V.; Sharafiev, A. V.; Soloviev, I. I.; Mukhanov, O. A.

    2017-10-01

    A new type of broadband active electrically small antenna (ESA) based on superconducting quantum arrays (SQAs) has been proposed and developed. These antennas are capable of providing both sensing and amplification of broadband electromagnetic signals with a very high spurious-free dynamic range (SFDR)—up to 100 dB (and even more)—with high sensitivity. The frequency band can range up to tens of gigahertz, depending on Josephson junction characteristic frequency, set by fabrication. In this paper we review theoretical and experimental studies of SQAs and SQA-based antenna prototypes of both transformer and transformer-less types. The ESA prototypes evaluated were fabricated using a standard Nb process with critical current density 4.5 kA cm-2. Measured device characteristics, design issues and comparative analysis of various ESA types, as well as requirements for interfaces, are reviewed and discussed.

  14. Complicated Electrical Activities in Cardiac Tissue

    Science.gov (United States)

    Shiau, Yuo-Hsien; Hsueh, Ming-Pin; Hseu, Shu-Shya; Yien, Huey-Wen

    It has become widely accepted that ventricular fibrillation, the most dangerous cardiac arrhythmias, is a major cause of death in the industrialized world. Alternans and conduction block have recently been related to the progression from ventricular tachycardia to ventricular fibrillation. From the point of view in cellular electrophysiology, ventricular tachycardia is the formation of reentrant wave in cardiac tissue. And ventricular fibrillation arises from subsequent breakdown of reentrant wave into multiple drifting and meandering spiral waves. In this paper, we numerically study pulse and vortex dynamics in cardiac tissue. Our numerical results include 1:1 normal sinus rhythm, 2:1 conduction block, complete conduction block, spiral wave, and spiral breakup. All of our numerical findings can be corresponding to clinical measurements in electrocardiogram. Various electrical activities in cardiac tissue will be discussed in detail in the present manuscript.

  15. Magnetism and Electricity Activity "Attracts" Student Interest

    Science.gov (United States)

    Roman, Harry T.

    2010-01-01

    Electricity and magnetism are intimately linked, this relationship forming the basis of the modern electric utility system and the generation of bulk electrical energy. There is rich literature from which to teach students the basics, but nothing drives the point home like having them learn from firsthand experience--and that is what this…

  16. Stereotactic biopsy with electrical monitoring for deep-seated brain tumors.

    Science.gov (United States)

    Ooba, Hiroshi; Abe, Tatsuya; Momii, Yasutomo; Fujiki, Minoru

    2013-01-01

    The stereotactic biopsy is widely integrated into clinical practice as an efficient and safe procedure for histologic diagnoses. However, the surgical risk increases when the lesions are close to the eloquence of the adjacent brain. The present report describes two patients with deep-seated brain tumors who underwent a stereotactic biopsy with electrical monitoring and demonstrates the importance of this technique. The tentative target and trajectory were determined on a stereotactic map from the Schaltenbrand and Wahren atlas. A Cosman-Roberts-Wells stereotactic frame was applied to the patient. Electrical recording along a single trajectory was used to identify the circumscribed neuronal structures, and electrical simulation was administered to the target. The biopsy point was decided when no adverse events were observed with a low electric current level. A 34-year-old male patient with anaplastic astrocytoma in the putamen and thalamus and an 81-year-old female patient with malignant lymphoma in the midbrain underwent stereotactic biopsies with electrical monitoring. The biopsies were successfully performed without any resulting neurologic deficits. This report describes two patients with deep-seated brain tumors who underwent stereotactic biopsies with electrical recording and stimulation. The electrical monitoring appears to be a useful technique to complement the ordinary image-guided biopsy. Copyright © 2013 Elsevier Inc. All rights reserved.

  17. Brain activity associated with translation from a visual to a symbolic representation in algebra and geometry.

    Science.gov (United States)

    Leikin, Mark; Waisman, Ilana; Shaul, Shelley; Leikin, Roza

    2014-03-01

    This paper presents a small part of a larger interdisciplinary study that investigates brain activity (using event related potential methodology) of male adolescents when solving mathematical problems of different types. The study design links mathematics education research with neurocognitive studies. In this paper we performed a comparative analysis of brain activity associated with the translation from visual to symbolic representations of mathematical objects in algebra and geometry. Algebraic tasks require translation from graphical to symbolic representation of a function, whereas tasks in geometry require translation from a drawing of a geometric figure to a symbolic representation of its property. The findings demonstrate that electrical activity associated with the performance of geometrical tasks is stronger than that associated with solving algebraic tasks. Additionally, we found different scalp topography of the brain activity associated with algebraic and geometric tasks. Based on these results, we argue that problem solving in algebra and geometry is associated with different patterns of brain activity.

  18. Predicting the electric field distribution in the brain for the treatment of glioblastoma.

    Science.gov (United States)

    Miranda, Pedro C; Mekonnen, Abeye; Salvador, Ricardo; Basser, Peter J

    2014-08-07

    The use of alternating electric fields has been recently proposed for the treatment of recurrent glioblastoma. In order to predict the electric field distribution in the brain during the application of such tumor treating fields (TTF), we constructed a realistic head model from MRI data and placed transducer arrays on the scalp to mimic an FDA-approved medical device. Values for the tissue dielectric properties were taken from the literature; values for the device parameters were obtained from the manufacturer. The finite element method was used to calculate the electric field distribution in the brain. We also included a 'virtual lesion' in the model to simulate the presence of an idealized tumor. The calculated electric field in the brain varied mostly between 0.5 and 2.0 V cm( - 1) and exceeded 1.0 V cm( - 1) in 60% of the total brain volume. Regions of local field enhancement occurred near interfaces between tissues with different conductivities wherever the electric field was perpendicular to those interfaces. These increases were strongest near the ventricles but were also present outside the tumor's necrotic core and in some parts of the gray matter-white matter interface. The electric field values predicted in this model brain are in reasonably good agreement with those that have been shown to reduce cancer cell proliferation in vitro. The electric field distribution is highly non-uniform and depends on tissue geometry and dielectric properties. This could explain some of the variability in treatment outcomes. The proposed modeling framework could be used to better understand the physical basis of TTF efficacy through retrospective analysis and to improve TTF treatment planning.

  19. Invasive and transcranial photoacoustic imaging of the vascular response to brain electrical stimulation

    Science.gov (United States)

    Tsytsarev, Vassiliy; Yao, Junjie; Hu, Song; Li, Li; Favazza, Christopher P.; Maslov, Konstantin I.; Wang, Lihong V.

    2010-02-01

    Advances in the brain functional imaging greatly facilitated the understanding of neurovascular coupling. For monitoring of the microvascular response to the brain electrical stimulation in vivo we used optical-resolution photoacoustic microscopy (OR-PAM) through the cranial openings as well as transcranially. Both types of the vascular response, vasoconstriction and vasodilatation, were clearly observed with good spatial and temporal resolution. Obtained results confirm one of the primary points of the neurovascular coupling theory that blood vessels could present vasoconstriction or vasodilatation in response to electrical stimulation, depending on the balance between inhibition and excitation of the different parts of the elements of the neurovascular coupling system.

  20. The fractionation of spoken language understanding by measuring electrical and magnetic brain signals.

    Science.gov (United States)

    Hagoort, Peter

    2008-03-12

    This paper focuses on what electrical and magnetic recordings of human brain activity reveal about spoken language understanding. Based on the high temporal resolution of these recordings, a fine-grained temporal profile of different aspects of spoken language comprehension can be obtained. Crucial aspects of speech comprehension are lexical access, selection and semantic integration. Results show that for words spoken in context, there is no 'magic moment' when lexical selection ends and semantic integration begins. Irrespective of whether words have early or late recognition points, semantic integration processing is initiated before words can be identified on the basis of the acoustic information alone. Moreover, for one particular event-related brain potential (ERP) component (the N400), equivalent impact of sentence- and discourse-semantic contexts is observed. This indicates that in comprehension, a spoken word is immediately evaluated relative to the widest interpretive domain available. In addition, this happens very quickly. Findings are discussed that show that often an unfolding word can be mapped onto discourse-level representations well before the end of the word. Overall, the time course of the ERP effects is compatible with the view that the different information types (lexical, syntactic, phonological, pragmatic) are processed in parallel and influence the interpretation process incrementally, that is as soon as the relevant pieces of information are available. This is referred to as the immediacy principle.

  1. Active seat isolation for hybrid electric vehicles

    Science.gov (United States)

    Leo, Donald J.; Malowicki, Mark; Buckley, Stephen J.; Naganathan, Ganapathy

    1999-07-01

    A feasibility study in the use of induced strain actuators for active seal isolation is described. The focus of the work is the isolation of lightweight automotive seats for hybrid-electric vehicles. The feasibility study is based on a numerical analysis of a three-degree-of-freedom vibration model of the seat. Mass and inertia properties are based on measurements from a powered seat that is found in current model year automobiles. Tradeoffs between vertical acceleration of the seat, actuator stroke requirements, and isolation frequency are determined through numerical analysis of the vibration model. Root mean square accelerations and actuator strokes are computed using power spectral densities that model broadband excitation and road excitation that is filtered by the vehicle suspension. Numerical results using the road excitation indicate that factors of two to three reduction in vertical acceleration are achieved when the active isolation frequency is reduced to approximately 1 Hz with damping factors on the order of 10 to 30 percent critical. More significant reductions are achieved in the case of broadband floor excitation. Root mean square actuator strokes for both case are int he range of 0.4 to 50 mm. Root mean square accelerations in the vertical direction are consistent with the levels found in standard comfort curves.

  2. Electrical Vehicles Activities Around the World

    DEFF Research Database (Denmark)

    Schauer, Gerd; Garcia-Valle, Rodrigo

    2013-01-01

    which have jointly changed how mobility is viewed in recent years. We describe key points concerning such field testing and the renaissance in electric vehicles that occurred around 2010. We discuss progress in lithium battery technology for high power and high energy density, improvement in integrated...... business models, and the availability of high-performance electric vehicles have become key enablers of this new technology. In this regard, it is promising that electric vehicles will soon be a part of a green transport solution (green mobility) powered by renewable energy and a new smart electricity......To understand the development of electric vehicles it is helpful to recognize constraints that were overcome during its history and the lessons learned from these constraints. In the earliest history of automobiles electrical cars initially dominated, but were pushed aside by cars with a combustion...

  3. Temperament, character and serotonin activity in the human brain

    DEFF Research Database (Denmark)

    Tuominen, L; Salo, J; Hirvonen, J

    2013-01-01

    The psychobiological model of personality by Cloninger and colleagues originally hypothesized that interindividual variability in the temperament dimension 'harm avoidance' (HA) is explained by differences in the activity of the brain serotonin system. We assessed brain serotonin transporter (5-HTT...

  4. Investigation of Brain Arterial Circle Malformations Using Electrical Modelling and Simulation

    Directory of Open Access Journals (Sweden)

    Klara Capova

    2006-01-01

    Full Text Available The paper deals with the cerebral arterial system investigation by means of electrical modelling and simulations. The main attention is paid to the brain arterial circle malformations (stenoses and aneurysms and their determination and evaluation by computer-aided methods as tools of a non-invasive diagnostics. The compensation possibilities of brain arterial circle in case of presence of concrete arterial malformations are modelled and simulated. The simulation results of brain arteries blood pressures and volume flow velocities time dependences are presented and discussed under various health conditions.

  5. Biomimetic Sonar for Electrical Activation of the Auditory Pathway

    Directory of Open Access Journals (Sweden)

    D. Menniti

    2017-01-01

    Full Text Available Relying on the mechanism of bat’s echolocation system, a bioinspired electronic device has been developed to investigate the cortical activity of mammals in response to auditory sensorial stimuli. By means of implanted electrodes, acoustical information about the external environment generated by a biomimetic system and converted in electrical signals was delivered to anatomically selected structures of the auditory pathway. Electrocorticographic recordings showed that cerebral activity response is highly dependent on the information carried out by ultrasounds and is frequency-locked with the signal repetition rate. Frequency analysis reveals that delta and beta rhythm content increases, suggesting that sensorial information is successfully transferred and integrated. In addition, principal component analysis highlights how all the stimuli generate patterns of neural activity which can be clearly classified. The results show that brain response is modulated by echo signal features suggesting that spatial information sent by biomimetic sonar is efficiently interpreted and encoded by the auditory system. Consequently, these results give new perspective in artificial environmental perception, which could be used for developing new techniques useful in treating pathological conditions or influencing our perception of the surroundings.

  6. Fluidic Active Transducer for Electricity Generation

    Science.gov (United States)

    Yang, Youngjun; Park, Junwoo; Kwon, Soon-Hyung; Kim, Youn Sang

    2015-10-01

    Flows in small size channels have been studied for a long time over multidisciplinary field such as chemistry, biology and medical through the various topics. Recently, the attempts of electricity generation from the small flows as a new area for energy harvesting in microfluidics have been reported. Here, we propose for the first time a new fluidic electricity generator (FEG) by modulating the electric double layer (EDL) with two phase flows of water and air without external power sources. We find that an electric current flowed by the forming/deforming of the EDL with a simple separated phase flow of water and air at the surface of the FEG. Electric signals between two electrodes of the FEG are checked from various water/air passing conditions. Moreover, we verify the possibility of a self-powered air slug sensor by applying the FEG in the detection of an air slug.

  7. In vivo modulation of hippocampal epileptiform activity with radial electric fields.

    Science.gov (United States)

    Richardson, Kristen A; Gluckman, Bruce J; Weinstein, Steven L; Glosch, Caryn E; Moon, Jessica B; Gwinn, Ryder P; Gale, Karen; Schiff, Steven J

    2003-06-01

    Electric field stimulation can interact with brain activity in a subthreshold manner. Electric fields have been previously adaptively applied to control seizures in vitro. We report the first results from establishing suitable electrode geometries and trajectories, as well as stimulation and recording electronics, to apply this technology in vivo. Electric field stimulation was performed in a rat kainic acid injection seizure model. Radial electric fields were generated unilaterally in hippocampus from an axial depth electrode. Both sinusoidal and multiphasic stimuli were applied. Hippocampal activity was recorded bilaterally from tungsten microelectrode pairs. Histologic examination was performed to establish electrode trajectory and characterize lesioning. Electric field modulation of epileptiform neural activity in phase with the stimulus was observed in five of six sinusoidal and six of six multiphasic waveform experiments. Both excitatory and suppressive modulation were observed in the two experiments with stimulation electrodes most centrally placed within the hippocampus. Distinctive modulation was observed in the period preceding seizure-onset detection in two of six experiments. Short-term histologic tissue damage was observed in one of six experiments associated with high unbalanced charge delivery. We demonstrated in vivo electric field modulation of epileptiform hippocampal activity, suggesting that electric field control of in vivo seizures may be technically feasible. The response to stimulation before seizure could be useful for triggering control systems, and may be a novel approach to define a preseizure state.

  8. Electroconvulsive therapy in the presence of deep brain stimulation implants: electric field effects.

    Science.gov (United States)

    Deng, Zhi-De; Hardesty, David E; Lisanby, Sarah H; Peterchev, Angel V

    2010-01-01

    The safety of electroconvulsive therapy (ECT) in patients who have deep brain stimulation (DBS) implants represents a significant clinical issue. A major safety concern is the presence of burr holes and electrode anchoring devices in the skull, which may alter the induced electric field distribution in the brain. We simulated the electric field using finite-element method in a five-shell spherical head model. Three DBS electrode anchoring techniques were modeled, including ring/cap, microplate, and burr-hole cover. ECT was modeled with bilateral (BL), right unilateral (RUL), and bifrontal (BF) electrode placements and with clinically-used stimulus current amplitude. We compared electric field strength and focality among the DBS implantation techniques and ECT electrode configurations. The simulation results show an increase in the electric field strength in the brain due to conduction through the burr holes, especially when the burr holes are not fitted with nonconductive caps. For typical burr hole placement for subthalamic nucleus DBS, the effect on the electric field strength and focality is strongest for BF ECT, which runs contrary to the belief that more anterior ECT electrode placements are safer in patients with DBS implants.

  9. [Geomagnetic storm decreases coherence of electric oscillations of human brain while working at the computer].

    Science.gov (United States)

    Novik, O B; Smirnov, F A

    2013-01-01

    The effect of geomagnetic storms at the latitude of Moscow on the electric oscillations of the human brain cerebral cortex was studied. In course of electroencephalogram measurements it was shown that when the voluntary persons at the age of 18-23 years old were performing tasks using a computer during moderate magnetic storm or no later than 24 hrs after it, the value of the coherence function of electric oscillations of the human brain in the frontal and occipital areas in a range of 4.0-7.9 Hz (so-called the theta rhythm oscillations of the human brain) decreased by a factor of two or more, sometimes reaching zero, although arterial blood pressure, respiratory rate and the electrocardiogram registered during electroencephalogram measurements remained within the standard values.

  10. Measurable benefits on brain activity from the practice of educational leisure

    Directory of Open Access Journals (Sweden)

    Carmen eRequena

    2014-03-01

    Full Text Available Even if behavioural studies relate leisure practices to the preservation of memory in old persons, there is unsubstantial evidence of the import of leisure on brain activity. Aim of this study was to compare the brain activity of elderly retired people who engage in different types of leisure activities. Methods: quasi-experimental study over a sample of 60 elderly, retired subjects distributed into three groups according to the leisure activities they practised: educational leisure (G1, memory games (G2 and card games (G3. Applied measures include the conceptual distinction between free time and leisure, the Test of Organization of Free Time (TOFT measuring 24 clock divisions, and EEG register during 12 word list memorizing. The results show that the type of leisure activity is associated with significant quantitative differences regarding the use of free time. G1 devotes more time to leisure activities than G2 (p = 0.007 and G3 (p = 0.034. G1 rests more actively than the other two groups (p=0.001. The electrical localization of brain activity indicated a reverse tendency of activation according to the bands and groups. Discussion. Engaging in educational leisure activities is a useful practice to protect healthy brain compensation strategies. Future longitudinal research may verify the causal relation between practicing educational leisure activities and functional brain aging.

  11. Measurable benefits on brain activity from the practice of educational leisure.

    Science.gov (United States)

    Requena, Carmen; López, Verónica

    2014-01-01

    Even if behavioral studies relate leisure practices to the preservation of memory in old persons, there is unsubstantial evidence of the import of leisure on brain activity. This study was to compare the brain activity of elderly retired people who engage in different types of leisure activities. Quasi-experimental study over a sample of 60 elderly, retired subjects distributed into three groups according to the leisure activities they practised: educational leisure (G1), memory games (G2), and card games (G3). Applied measures include the conceptual distinction between free time and leisure, the test of the organization of free time measuring 24 clock divisions, and EEG register during 12 word list memorizing. The results show that the type of leisure activity is associated with significant quantitative differences regarding the use of free time. G1 devotes more time to leisure activities than G2 (p = 0.007) and G3 (p = 0.034). G1 rests more actively than the other two groups (p = 0.001). The electrical localization of brain activity indicated a reverse tendency of activation according to the bands and groups. Engaging in educational leisure activities is a useful practice to protect healthy brain compensation strategies. Future longitudinal research may verify the causal relation between practicing educational leisure activities and functional brain aging.

  12. Measurable benefits on brain activity from the practice of educational leisure

    Science.gov (United States)

    Requena, Carmen; López, Verónica

    2014-01-01

    Even if behavioral studies relate leisure practices to the preservation of memory in old persons, there is unsubstantial evidence of the import of leisure on brain activity. Aim: This study was to compare the brain activity of elderly retired people who engage in different types of leisure activities. Methods: Quasi-experimental study over a sample of 60 elderly, retired subjects distributed into three groups according to the leisure activities they practised: educational leisure (G1), memory games (G2), and card games (G3). Applied measures include the conceptual distinction between free time and leisure, the test of the organization of free time measuring 24 clock divisions, and EEG register during 12 word list memorizing. Results: The results show that the type of leisure activity is associated with significant quantitative differences regarding the use of free time. G1 devotes more time to leisure activities than G2 (p = 0.007) and G3 (p = 0.034). G1 rests more actively than the other two groups (p = 0.001). The electrical localization of brain activity indicated a reverse tendency of activation according to the bands and groups. Discussion: Engaging in educational leisure activities is a useful practice to protect healthy brain compensation strategies. Future longitudinal research may verify the causal relation between practicing educational leisure activities and functional brain aging. PMID:24653699

  13. Memory scrutinized through electrical brain stimulation: A review of 80 years of experiential phenomena.

    Science.gov (United States)

    Curot, Jonathan; Busigny, Thomas; Valton, Luc; Denuelle, Marie; Vignal, Jean-Pierre; Maillard, Louis; Chauvel, Patrick; Pariente, Jérémie; Trebuchon, Agnès; Bartolomei, Fabrice; Barbeau, Emmanuel J

    2017-07-01

    Electrical brain stimulations (EBS) sometimes induce reminiscences, but it is largely unknown what type of memories they can trigger. We reviewed 80 years of literature on reminiscences induced by EBS and added our own database. We classified them according to modern conceptions of memory. We observed a surprisingly large variety of reminiscences covering all aspects of declarative memory. However, most were poorly detailed and only a few were episodic. This result does not support theories of a highly stable and detailed memory, as initially postulated, and still widely believed as true by the general public. Moreover, memory networks could only be activated by some of their nodes: 94.1% of EBS were temporal, although the parietal and frontal lobes, also involved in memory networks, were stimulated. The qualitative nature of memories largely depended on the site of stimulation: EBS to rhinal cortex mostly induced personal semantic reminiscences, while only hippocampal EBS induced episodic memories. This result supports the view that EBS can activate memory in predictable ways in humans. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  14. Physical activity and brain plasticity in late adulthood.

    Science.gov (United States)

    Erickson, Kirk I; Gildengers, Ariel G; Butters, Meryl A

    2013-03-01

    The human brain shrinks with advancing age, but recent research suggests that it is also capable of remarkable plasticity, even in late life. In this review we summarize the research linking greater amounts of physical activity to less cortical atrophy, better brain function, and enhanced cognitive function, and argue that physical activity takes advantage of the brain's natural capacity for plasticity. Further, although the effects of physical activity on the brain are relatively widespread, there is also some specificity, such that prefrontal and hippocampal areas appear to be more influenced than other areas of the brain. The specificity of these effects, we argue, provides a biological basis for understanding the capacity for physical activity to influence neurocognitive and neuropsychiatric disorders such as depression. We conclude that physical activity is a promising intervention that can influence the endogenous pharmacology of the brain to enhance cognitive and emotional function in late adulthood.

  15. Cognitive Control of Language Production in Bilinguals Involves a Partly Independent Process within the Domain-General Cognitive Control Network: Evidence from Task-switching and Electrical Brain Activity

    Science.gov (United States)

    Magezi, David A.; Khateb, Asaid; Mouthon, Michael; Spierer, Lucas; Annoni, Jean-Marie

    2012-01-01

    In highly proficient, early bilinguals, behavioural studies of the cost of switching language or task suggest qualitative differences between language control and domain-general cognitive control. By contrast, several neuroimaging studies have shown an overlap of the brain areas involved in language control and domain-general cognitive control.…

  16. Prolonged Intracellular Na+ Dynamics Govern Electrical Activity in Accessory Olfactory Bulb Mitral Cells.

    Directory of Open Access Journals (Sweden)

    Asaph Zylbertal

    2015-12-01

    Full Text Available Persistent activity has been reported in many brain areas and is hypothesized to mediate working memory and emotional brain states and to rely upon network or biophysical feedback. Here, we demonstrate a novel mechanism by which persistent neuronal activity can be generated without feedback, relying instead on the slow removal of Na+ from neurons following bursts of activity. We show that mitral cells in the accessory olfactory bulb (AOB, which plays a major role in mammalian social behavior, may respond to a brief sensory stimulation with persistent firing. By combining electrical recordings, Ca2+ and Na+ imaging, and realistic computational modeling, we explored the mechanisms underlying the persistent activity in AOB mitral cells. We found that the exceptionally slow inward current that underlies this activity is governed by prolonged dynamics of intracellular Na+ ([Na+]i, which affects neuronal electrical activity via several pathways. Specifically, elevated dendritic [Na+]i reverses the Na+-Ca2+ exchanger activity, thus modifying the [Ca2+]i set-point. This process, which relies on ubiquitous membrane mechanisms, is likely to play a role in other neuronal types in various brain regions.

  17. Mapping effective connectivity in the human brain with concurrent intracranial electrical stimulation and BOLD-fMRI.

    Science.gov (United States)

    Oya, Hiroyuki; Howard, Matthew A; Magnotta, Vincent A; Kruger, Anton; Griffiths, Timothy D; Lemieux, Louis; Carmichael, David W; Petkov, Christopher I; Kawasaki, Hiroto; Kovach, Christopher K; Sutterer, Matthew J; Adolphs, Ralph

    2017-02-01

    Understanding brain function requires knowledge of how one brain region causally influences another. This information is difficult to obtain directly in the human brain, and is instead typically inferred from resting-state fMRI. Here, we demonstrate the safety and scientific promise of a novel and complementary approach: concurrent electrical stimulation and fMRI (es-fMRI) at 3T in awake neurosurgical patients with implanted depth electrodes. We document the results of safety testing, actual experimental setup, and stimulation parameters, that safely and reliably evoke activation in distal structures through stimulation of amygdala, cingulate, or prefrontal cortex. We compare connectivity inferred from the evoked patterns of activation with that estimated from standard resting-state fMRI in the same patients: while connectivity patterns obtained with each approach are correlated, each method produces unique results. Response patterns were stable over the course of 11min of es-fMRI runs. COMPARISON WITH EXISTING METHOD: es-fMRI in awake humans yields unique information about effective connectivity, complementing resting-state fMRI. Although our stimulations were below the level of inducing any apparent behavioral or perceptual effects, a next step would be to use es-fMRI to modulate task performances. This would reveal the acute network-level changes induced by the stimulation that mediate the behavioral and cognitive effects seen with brain stimulation. es-fMRI provides a novel and safe approach for mapping effective connectivity in the human brain in a clinical setting, and will inform treatments for psychiatric and neurodegenerative disorders that use deep brain stimulation. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. BrainK for Structural Image Processing: Creating Electrical Models of the Human Head

    Directory of Open Access Journals (Sweden)

    Kai Li

    2016-01-01

    Full Text Available BrainK is a set of automated procedures for characterizing the tissues of the human head from MRI, CT, and photogrammetry images. The tissue segmentation and cortical surface extraction support the primary goal of modeling the propagation of electrical currents through head tissues with a finite difference model (FDM or finite element model (FEM created from the BrainK geometries. The electrical head model is necessary for accurate source localization of dense array electroencephalographic (dEEG measures from head surface electrodes. It is also necessary for accurate targeting of cerebral structures with transcranial current injection from those surface electrodes. BrainK must achieve five major tasks: image segmentation, registration of the MRI, CT, and sensor photogrammetry images, cortical surface reconstruction, dipole tessellation of the cortical surface, and Talairach transformation. We describe the approach to each task, and we compare the accuracies for the key tasks of tissue segmentation and cortical surface extraction in relation to existing research tools (FreeSurfer, FSL, SPM, and BrainVisa. BrainK achieves good accuracy with minimal or no user intervention, it deals well with poor quality MR images and tissue abnormalities, and it provides improved computational efficiency over existing research packages.

  19. The impact of large structural brain changes in chronic stroke patients on the electric field caused by transcranial brain stimulation

    DEFF Research Database (Denmark)

    Minjoli, Sena; Saturnino, Guilherme B.; Blicher, Jakob Udby

    2017-01-01

    Transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (TDCS) are two types of non-invasive transcranial brain stimulation (TBS). They are useful tools for stroke research and may be potential adjunct therapies for functional recovery. However, stroke often causes large...... aimed to characterize the impact of these changes on the spatial distribution of the electric field generated by both TBS methods. In addition to confirming the safety of TBS in the presence of large stroke-related structural changes, our aim was to clarify whether targeted stimulation is still possible...

  20. Lisuride and cerebral electrical activity in the rabbit.

    Science.gov (United States)

    Bo, P; Maurelli, M; Nappi, G; Savoldi, F

    1981-05-01

    This study was meant to investigate the action of lisuride hydrogen maleate on somatic and visceral behaviour, and on cerebral electrical activity. With regard to the cortical and deep components of electrical activity, we recorded arousal and, at times, the onset of epileptic activity, mainly from the rhinencephalic area and sometimes spreading to other cerebral structures. We also report the results obtained in rabbits treated acutely and chronically by us with neuroleptics.

  1. [Changes in brain bioelectrical activity during xenon anesthesia in neurosurgical patients].

    Science.gov (United States)

    Rylova, A V; Sazonova, O B; Lubnin, A Iu; Masherov, E L

    2010-01-01

    Xenon is a promising anesthetic agent in neurosurgery. However, there is now little evidence on the effect of xenon at anesthetic concentrations on brain electrical activity, which limits its use in neurosurgical patients. Changes in brain bioelectrical activity were studied in patients with skull base tumors before surgery (conscious ones) and at different stages of xenon anesthesia (after denitrogenization, at 50% xenon concentration in the circuit, at 65% xenon concentration in the circuit, during steady-state xenon anesthesia, and after hyperventilation). EEG during xenon anesthesia was similar to that during propofol anesthesia; a circuit xenon concentration (50 or 65%) and a ventilation mode had no considerable impact on EEG. Xenon did not induce paroxysmal activity. The findings suggest that the use of xenon anesthesia in neurosurgical patients is safe in terms of its impact on brain bioelectrical activity.

  2. Evaluation method for in situ electric field in standardized human brain for different transcranial magnetic stimulation coils.

    Science.gov (United States)

    Iwahashi, Masahiro; Gomez-Tames, Jose; Laakso, Ilkka; Hirata, Akimasa

    2017-03-21

    This study proposes a method to evaluate the electric field induced in the brain by transcranial magnetic stimulation (TMS) to realize focal stimulation in the target area considering the inter-subject difference of the brain anatomy. The TMS is a non-invasive technique used for treatment/diagnosis, and it works by inducing an electric field in a specific area of the brain via a coil-induced magnetic field. Recent studies that report on the electric field distribution in the brain induced by TMS coils have been limited to simplified human brain models or a small number of detailed human brain models. Until now, no method has been developed that appropriately evaluates the coil performance for a group of subjects. In this study, we first compare the magnetic field and the magnetic vector potential distributions to determine if they can be used as predictors of the TMS focality derived from the electric field distribution. Next, the hotspots of the electric field on the brain surface of ten subjects using six coils are compared. Further, decisive physical factors affecting the focality of the induced electric field by different coils are discussed by registering the computed electric field in a standard brain space for the first time, so as to evaluate coil characteristics for a large population of subjects. The computational results suggest that the induced electric field in the target area cannot be generalized without considering the morphological variability of the human brain. Moreover, there was no remarkable difference between the various coils, although focality could be improved to a certain extent by modifying the coil design (e.g., coil radius). Finally, the focality estimated by the electric field was more correlated with the magnetic vector potential than the magnetic field in a homogeneous sphere.

  3. Evaluation method for in situ electric field in standardized human brain for different transcranial magnetic stimulation coils

    Science.gov (United States)

    Iwahashi, Masahiro; Gomez-Tames, Jose; Laakso, Ilkka; Hirata, Akimasa

    2017-03-01

    This study proposes a method to evaluate the electric field induced in the brain by transcranial magnetic stimulation (TMS) to realize focal stimulation in the target area considering the inter-subject difference of the brain anatomy. The TMS is a non-invasive technique used for treatment/diagnosis, and it works by inducing an electric field in a specific area of the brain via a coil-induced magnetic field. Recent studies that report on the electric field distribution in the brain induced by TMS coils have been limited to simplified human brain models or a small number of detailed human brain models. Until now, no method has been developed that appropriately evaluates the coil performance for a group of subjects. In this study, we first compare the magnetic field and the magnetic vector potential distributions to determine if they can be used as predictors of the TMS focality derived from the electric field distribution. Next, the hotspots of the electric field on the brain surface of ten subjects using six coils are compared. Further, decisive physical factors affecting the focality of the induced electric field by different coils are discussed by registering the computed electric field in a standard brain space for the first time, so as to evaluate coil characteristics for a large population of subjects. The computational results suggest that the induced electric field in the target area cannot be generalized without considering the morphological variability of the human brain. Moreover, there was no remarkable difference between the various coils, although focality could be improved to a certain extent by modifying the coil design (e.g., coil radius). Finally, the focality estimated by the electric field was more correlated with the magnetic vector potential than the magnetic field in a homogeneous sphere.

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

    Science.gov (United States)

    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 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. PMID:25206446

  5. An electrically active microneedle array for electroporation

    Science.gov (United States)

    Choi, Seong-O; Kim, Yeu Chun; Park, Jung-Hwan; Hutcheson, Joshua; Gill, Harvinder S.; Yoon, Yong-Kyu; Prausnitz, Mark R.; Allen, Mark G.

    2010-01-01

    We have designed and fabricated a microneedle array with electrical functionality with the final goal of electroporating skin’s epidermal cells to increase their transfection by DNA vaccines. The microneedle array was made of polymethylmethacrylate (PMMA) by micromolding technology from a master PDMS mold, followed by metal deposition, patterning using laser ablation, and electrodeposition. This microneedle array possessed sufficient mechanical strength to penetrate human skin in vivo and was also able to electroporate both red blood cells and human prostate cancer cells as an in vitro model to demonstrate cell membrane permeabilization. A model to predict the effective volume for electroporation with respect to applied voltages was constructed from finite element simulation. This study demonstrates the mechanical and electrical functionalities of the first MEMS-fabricated microneedle array for electroporation, designed for DNA vaccine delivery. PMID:20012696

  6. Potential Moderators of Physical Activity on Brain Health

    Directory of Open Access Journals (Sweden)

    Regina L. Leckie

    2012-01-01

    Full Text Available Age-related cognitive decline is linked to numerous molecular, structural, and functional changes in the brain. However, physical activity is a promising method of reducing unfavorable age-related changes. Physical activity exerts its effects on the brain through many molecular pathways, some of which are regulated by genetic variants in humans. In this paper, we highlight genes including apolipoprotein E (APOE, brain derived neurotrophic factor (BDNF, and catechol-O-methyltransferase (COMT along with dietary omega-3 fatty acid, docosahexaenoic acid (DHA, as potential moderators of the effect of physical activity on brain health. There are a growing number of studies indicating that physical activity might mitigate the genetic risks for disease and brain dysfunction and that the combination of greater amounts of DHA intake with physical activity might promote better brain function than either treatment alone. Understanding whether genes or other lifestyles moderate the effects of physical activity on neurocognitive health is necessary for delineating the pathways by which brain health can be enhanced and for grasping the individual variation in the effectiveness of physical activity interventions on the brain and cognition. There is a need for future research to continue to assess the factors that moderate the effects of physical activity on neurocognitive function.

  7. A Closed Loop Brain-machine Interface for Epilepsy Control Using Dorsal Column Electrical Stimulation.

    Science.gov (United States)

    Pais-Vieira, Miguel; Yadav, Amol P; Moreira, Derek; Guggenmos, David; Santos, Amílcar; Lebedev, Mikhail; Nicolelis, Miguel A L

    2016-09-08

    Although electrical neurostimulation has been proposed as an alternative treatment for drug-resistant cases of epilepsy, current procedures such as deep brain stimulation, vagus, and trigeminal nerve stimulation are effective only in a fraction of the patients. Here we demonstrate a closed loop brain-machine interface that delivers electrical stimulation to the dorsal column (DCS) of the spinal cord to suppress epileptic seizures. Rats were implanted with cortical recording microelectrodes and spinal cord stimulating electrodes, and then injected with pentylenetetrazole to induce seizures. Seizures were detected in real time from cortical local field potentials, after which DCS was applied. This method decreased seizure episode frequency by 44% and seizure duration by 38%. We argue that the therapeutic effect of DCS is related to modulation of cortical theta waves, and propose that this closed-loop interface has the potential to become an effective and semi-invasive treatment for refractory epilepsy and other neurological disorders.

  8. Brain activity associated with illusory correlations in animal phobia.

    Science.gov (United States)

    Wiemer, Julian; Schulz, Stefan M; Reicherts, Philipp; Glotzbach-Schoon, Evelyn; Andreatta, Marta; Pauli, Paul

    2015-07-01

    Anxiety disorder patients were repeatedly found to overestimate the association between disorder-relevant stimuli and aversive outcomes despite random contingencies. Such an illusory correlation (IC) might play an important role in the return of fear after extinction learning; yet, little is known about how this cognitive bias emerges in the brain. In a functional magnetic resonance imaging study, 18 female patients with spider phobia and 18 healthy controls were exposed to pictures of spiders, mushrooms and puppies followed randomly by either a painful electrical shock or nothing. In advance, both patients and healthy controls expected more shocks after spider pictures. Importantly, only patients with spider phobia continued to overestimate this association after the experiment. The strength of this IC was predicted by increased outcome aversiveness ratings and primary sensory motor cortex activity in response to the shock after spider pictures. Moreover, increased activation of the left dorsolateral prefrontal cortex (dlPFC) to spider pictures predicted the IC. These results support the theory that phobia-relevant stimuli amplify unpleasantness and sensory motor representations of aversive stimuli, which in turn may promote their overestimation. Hyper-activity in dlPFC possibly reflects a pre-occupation of executive resources with phobia-relevant stimuli, thus complicating the accurate monitoring of objective contingencies and the unlearning of fear. © The Author (2014). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

  9. The impact of large structural brain changes in chronic stroke patients on the electric field caused by transcranial brain stimulation

    Directory of Open Access Journals (Sweden)

    Sena Minjoli

    2017-01-01

    Full Text Available Transcranial magnetic stimulation (TMS and transcranial direct current stimulation (TDCS are two types of non-invasive transcranial brain stimulation (TBS. They are useful tools for stroke research and may be potential adjunct therapies for functional recovery. However, stroke often causes large cerebral lesions, which are commonly accompanied by a secondary enlargement of the ventricles and atrophy. These structural alterations substantially change the conductivity distribution inside the head, which may have potentially important consequences for both brain stimulation methods. We therefore aimed to characterize the impact of these changes on the spatial distribution of the electric field generated by both TBS methods. In addition to confirming the safety of TBS in the presence of large stroke-related structural changes, our aim was to clarify whether targeted stimulation is still possible. Realistic head models containing large cortical and subcortical stroke lesions in the right parietal cortex were created using MR images of two patients. For TMS, the electric field of a double coil was simulated using the finite-element method. Systematic variations of the coil position relative to the lesion were tested. For TDCS, the finite-element method was used to simulate a standard approach with two electrode pads, and the position of one electrode was systematically varied. For both TMS and TDCS, the lesion caused electric field “hot spots” in the cortex. However, these maxima were not substantially stronger than those seen in a healthy control. The electric field pattern induced by TMS was not substantially changed by the lesions. However, the average field strength generated by TDCS was substantially decreased. This effect occurred for both head models and even when both electrodes were distant to the lesion, caused by increased current shunting through the lesion and enlarged ventricles. Judging from the similar peak field strengths compared

  10. The impact of large structural brain changes in chronic stroke patients on the electric field caused by transcranial brain stimulation.

    Science.gov (United States)

    Minjoli, Sena; Saturnino, Guilherme B; Blicher, Jakob Udby; Stagg, Charlotte J; Siebner, Hartwig R; Antunes, André; Thielscher, Axel

    2017-01-01

    Transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (TDCS) are two types of non-invasive transcranial brain stimulation (TBS). They are useful tools for stroke research and may be potential adjunct therapies for functional recovery. However, stroke often causes large cerebral lesions, which are commonly accompanied by a secondary enlargement of the ventricles and atrophy. These structural alterations substantially change the conductivity distribution inside the head, which may have potentially important consequences for both brain stimulation methods. We therefore aimed to characterize the impact of these changes on the spatial distribution of the electric field generated by both TBS methods. In addition to confirming the safety of TBS in the presence of large stroke-related structural changes, our aim was to clarify whether targeted stimulation is still possible. Realistic head models containing large cortical and subcortical stroke lesions in the right parietal cortex were created using MR images of two patients. For TMS, the electric field of a double coil was simulated using the finite-element method. Systematic variations of the coil position relative to the lesion were tested. For TDCS, the finite-element method was used to simulate a standard approach with two electrode pads, and the position of one electrode was systematically varied. For both TMS and TDCS, the lesion caused electric field "hot spots" in the cortex. However, these maxima were not substantially stronger than those seen in a healthy control. The electric field pattern induced by TMS was not substantially changed by the lesions. However, the average field strength generated by TDCS was substantially decreased. This effect occurred for both head models and even when both electrodes were distant to the lesion, caused by increased current shunting through the lesion and enlarged ventricles. Judging from the similar peak field strengths compared to the healthy

  11. Non-invasive electrical and magnetic stimulation of the brain, spinal cord, roots and peripheral nerves

    DEFF Research Database (Denmark)

    Rossini, P M; Burke, D; Chen, R

    2015-01-01

    These guidelines provide an up-date of previous IFCN report on "Non-invasive electrical and magnetic stimulation of the brain, spinal cord and roots: basic principles and procedures for routine clinical application" (Rossini et al., 1994). A new Committee, composed of international experts, some...... theoretical, physiological and practical aspects of non-invasive stimulation of brain, spinal cord, nerve roots and peripheral nerves in the light of more updated knowledge, and include some recent extensions and developments....... of whom were in the panel of the 1994 "Report", was selected to produce a current state-of-the-art review of non-invasive stimulation both for clinical application and research in neuroscience. Since 1994, the international scientific community has seen a rapid increase in non-invasive brain stimulation...

  12. Metformin induces up-regulation of blood-brain barrier functions by activating AMP-activated protein kinase in rat brain microvascular endothelial cells.

    Science.gov (United States)

    Takata, Fuyuko; Dohgu, Shinya; Matsumoto, Junichi; Machida, Takashi; Kaneshima, Shuji; Matsuo, Mai; Sakaguchi, Shinya; Takeshige, Yuki; Yamauchi, Atsushi; Kataoka, Yasufumi

    2013-04-19

    Blood-brain barrier (BBB) disruption occurs frequently in CNS diseases and injuries. Few drugs have been developed as therapeutic candidates for facilitating BBB functions. Here, we examined whether metformin up-regulates BBB functions using rat brain microvascular endothelial cells (RBECs). Metformin, concentration- and time-dependently increased transendothelial electrical resistance of RBEC monolayers, and decreased RBEC permeability to sodium fluorescein and Evans blue albumin. These effects of metformin were blocked by compound C, an inhibitor of AMP-activated protein kinase (AMPK). AMPK stimulation with an AMPK activator, AICAR, enhanced BBB functions. These findings indicate that metformin induces up-regulation of BBB functions via AMPK activation. Copyright © 2013 Elsevier Inc. All rights reserved.

  13. Syndrome of Electrical Status Epilepticus During Sleep: Epileptic Encephalopathy Related to Brain Development.

    Science.gov (United States)

    Chen, Xiao-Qiao; Zhang, Wei-Na; Hu, Lin-Yan; Liu, Meng-Jia; Zou, Li-Ping

    2016-03-01

    Epileptic encephalopathy with electrical status epilepticus during sleep is an age-related and self-limited disorder. The present study analyzed the etiology, demographics, and pathogenesis of patients with electrical status epilepticus during sleep to provide information on the diagnosis and therapy of this syndrome. The etiologies of epileptic encephalopathy with electrical status epilepticus during sleep in patients admitted in Chinese People's Liberation Army General Hospital from 2009 to 2014 were retrospectively analyzed. Patients were classified into the genetic, structural-metabolic, and unknown groups according to the etiology. Demographics and clinical characteristics of all the patients were then analyzed and compared among groups. The etiologies of epileptic encephalopathy with electrical status epilepticus during sleep in 75 patients mainly included benign childhood epilepsy with centrotemporal spikes, Landau-Kleffner syndrome, polymicrogyria, and migration disorders. Age at onset of epilepsy did not show a specific pattern, but age at onset of epileptic encephalopathy with electrical status epilepticus during sleep was concentrated at age 6-9 years. The mean age at onset of epilepsy in the genetic group was significantly older than that in the structural-metabolic group (P sleep did not significantly differ between the two groups. Electrical status epilepticus during sleep is an epileptic encephalopathy related to brain development and presents an age-dependent occurrence. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Spontaneous Electrical Activity in the Nervous System and its ...

    African Journals Online (AJOL)

    The present study was carried out to examine the effects of biogenic amines on the spontaneous electrical activity of the nervous system in the silkworm Bombyx mori. The activity recorded from different segments of the ventral nerve cord differed in the frequency and number of spike categories firing. The activity was highest ...

  15. Intelligent Electric Power Systems with Active-Adaptive Electric Networks: Challenges for Simulation Tools

    Directory of Open Access Journals (Sweden)

    Ufa Ruslan A.

    2015-01-01

    Full Text Available The motivation of the presented research is based on the needs for development of new methods and tools for adequate simulation of intelligent electric power systems with active-adaptive electric networks (IES including Flexible Alternating Current Transmission System (FACTS devices. The key requirements for the simulation were formed. The presented analysis of simulation results of IES confirms the need to use a hybrid modelling approach.

  16. Resting Brain Activity Related to Dispositional Mindfulness: a PET Study

    OpenAIRE

    Gartenschl?ger, Martin; Schreckenberger, Mathias; Buchholz, Hans-Georg; Reiner, Iris; Beutel, Manfred E.; Adler, Julia; Michal, Matthias

    2017-01-01

    Mindfulness denotes a state of consciousness characterized by receptive attention to and awareness of present events and experiences. As a personality trait, it constitutes the ability to become aware of mental activities such as sensations, images, feelings, and thoughts, and to disengage from judgment, conditioned emotions, and their cognitive processing or automatic inhibition. Default brain activity reflects the stream of consciousness and sense of self at rest. Analysis of brain activity...

  17. Human brain activity patterns beyond the isoelectric line of extreme deep coma.

    Directory of Open Access Journals (Sweden)

    Daniel Kroeger

    Full Text Available The electroencephalogram (EEG reflects brain electrical activity. A flat (isoelectric EEG, which is usually recorded during very deep coma, is considered to be a turning point between a living brain and a deceased brain. Therefore the isoelectric EEG constitutes, together with evidence of irreversible structural brain damage, one of the criteria for the assessment of brain death. In this study we use EEG recordings for humans on the one hand, and on the other hand double simultaneous intracellular recordings in the cortex and hippocampus, combined with EEG, in cats. They serve to demonstrate that a novel brain phenomenon is observable in both humans and animals during coma that is deeper than the one reflected by the isoelectric EEG, and that this state is characterized by brain activity generated within the hippocampal formation. This new state was induced either by medication applied to postanoxic coma (in human or by application of high doses of anesthesia (isoflurane in animals leading to an EEG activity of quasi-rhythmic sharp waves which henceforth we propose to call ν-complexes (Nu-complexes. Using simultaneous intracellular recordings in vivo in the cortex and hippocampus (especially in the CA3 region we demonstrate that ν-complexes arise in the hippocampus and are subsequently transmitted to the cortex. The genesis of a hippocampal ν-complex depends upon another hippocampal activity, known as ripple activity, which is not overtly detectable at the cortical level. Based on our observations, we propose a scenario of how self-oscillations in hippocampal neurons can lead to a whole brain phenomenon during coma.

  18. Effects of geomagnetic activity on the mesospheric electric fields

    Directory of Open Access Journals (Sweden)

    A. M. Zadorozhny

    1998-12-01

    Full Text Available The results of three series of rocket measurements of mesospheric electric fields carried out under different geomagnetic conditions at polar and high middle latitudes are analysed. The measurements show a clear dependence of the vertical electric fields on geomagnetic activity at polar and high middle latitudes. The vertical electric fields in the lower mesosphere increase with the increase of geomagnetic indexes Kp and ∑Kp. The simultaneous increase of the vertical electric field strength and ion conductivity was observed in the mesosphere during geomagnetic disturbances. This striking phenomenon was displayed most clearly during the solar proton events of October, 1989 accompanied by very strong geomagnetic storm (Kp=8+. A possible mechanism of generation of the vertical electric fields in the mesosphere caused by gravitational sedimentation of charged aerosol particles is discussed. Simultaneous existence in the mesosphere of both the negative and positive multiply charged aerosol particles of different sizes is assumed for explanation of the observed V/m vertical electric fields and their behaviour under geomagnetically disturbed conditions.Keywords. Atmospheric composition and structure (aerosols and particles · Ionosphere (electric fields and currents · Meteorology and atmospheric dynamics (atmospheric electricity

  19. Effects of geomagnetic activity on the mesospheric electric fields

    Directory of Open Access Journals (Sweden)

    A. M. Zadorozhny

    Full Text Available The results of three series of rocket measurements of mesospheric electric fields carried out under different geomagnetic conditions at polar and high middle latitudes are analysed. The measurements show a clear dependence of the vertical electric fields on geomagnetic activity at polar and high middle latitudes. The vertical electric fields in the lower mesosphere increase with the increase of geomagnetic indexes Kp and ∑Kp. The simultaneous increase of the vertical electric field strength and ion conductivity was observed in the mesosphere during geomagnetic disturbances. This striking phenomenon was displayed most clearly during the solar proton events of October, 1989 accompanied by very strong geomagnetic storm (Kp=8+. A possible mechanism of generation of the vertical electric fields in the mesosphere caused by gravitational sedimentation of charged aerosol particles is discussed. Simultaneous existence in the mesosphere of both the negative and positive multiply charged aerosol particles of different sizes is assumed for explanation of the observed V/m vertical electric fields and their behaviour under geomagnetically disturbed conditions.

    Keywords. Atmospheric composition and structure (aerosols and particles · Ionosphere (electric fields and currents · Meteorology and atmospheric dynamics (atmospheric electricity

  20. Quantitative conductivity and permittivity imaging of the human brain using electric properties tomography.

    Science.gov (United States)

    Voigt, Tobias; Katscher, Ulrich; Doessel, Olaf

    2011-08-01

    The electric properties of human tissue can potentially be used as an additional diagnostic parameter, e.g., in tumor diagnosis. In the framework of radiofrequency safety, the electric conductivity of tissue is needed to correctly estimate the local specific absorption rate distribution during MR measurements. In this study, a recently developed approach, called electric properties tomography (EPT) is adapted for and applied to in vivo imaging. It derives the patient's electric conductivity and permittivity from the spatial sensitivity distributions of the applied radiofrequency coils. In contrast to other methods to measure the patient's electric properties, EPT does not apply externally mounted electrodes, currents, or radiofrequency probes, which enhances the practicability of the approach. This work shows that conductivity distributions can be reconstructed from phase images and permittivity distributions can be reconstructed from magnitude images of the radiofrequency transmit field. Corresponding numerical simulations using finite-difference time-domain methods support the feasibility of this phase-based conductivity imaging and magnitude-based permittivity imaging. Using this approximation, three-dimensional in vivo conductivity and permittivity maps of the human brain are obtained in 5 and 13 min, respectively, which can be considered a step toward clinical feasibility for EPT. Copyright © 2011 Wiley-Liss, Inc.

  1. Spatial heterogeneity analysis of brain activation in fMRI

    Directory of Open Access Journals (Sweden)

    Lalit Gupta

    2014-01-01

    Full Text Available In many brain diseases it can be qualitatively observed that spatial patterns in blood oxygenation level dependent (BOLD activation maps appear more (diffusively distributed than in healthy controls. However, measures that can quantitatively characterize this spatial distributiveness in individual subjects are lacking. In this study, we propose a number of spatial heterogeneity measures to characterize brain activation maps. The proposed methods focus on different aspects of heterogeneity, including the shape (compactness, complexity in the distribution of activated regions (fractal dimension and co-occurrence matrix, and gappiness between activated regions (lacunarity. To this end, functional MRI derived activation maps of a language and a motor task were obtained in language impaired children with (Rolandic epilepsy and compared to age-matched healthy controls. Group analysis of the activation maps revealed no significant differences between patients and controls for both tasks. However, for the language task the activation maps in patients appeared more heterogeneous than in controls. Lacunarity was the best measure to discriminate activation patterns of patients from controls (sensitivity 74%, specificity 70% and illustrates the increased irregularity of gaps between activated regions in patients. The combination of heterogeneity measures and a support vector machine approach yielded further increase in sensitivity and specificity to 78% and 80%, respectively. This illustrates that activation distributions in impaired brains can be complex and more heterogeneous than in normal brains and cannot be captured fully by a single quantity. In conclusion, heterogeneity analysis has potential to robustly characterize the increased distributiveness of brain activation in individual patients.

  2. Brain activation during human male ejaculation

    NARCIS (Netherlands)

    Holstege, Ger; Georgiadis, Janniko R.; Paans, Anne M.J.; Meiners, Linda C.; Graaf, Ferdinand H.C.E. van der; Reinders, A.A.T.Simone

    2003-01-01

    Brain mechanisms that control human sexual behavior in general, and ejaculation in particular, are poorly understood. We used positron emission tomography to measure increases in regional cerebral blood flow (rCBF) during ejaculation compared with sexual stimulation in heterosexual male volunteers.

  3. Modelling the Effects of Electrical Coupling between Unmyelinated Axons of Brainstem Neurons Controlling Rhythmic Activity.

    Directory of Open Access Journals (Sweden)

    Michael J Hull

    2015-05-01

    Full Text Available Gap junctions between fine unmyelinated axons can electrically couple groups of brain neurons to synchronise firing and contribute to rhythmic activity. To explore the distribution and significance of electrical coupling, we modelled a well analysed, small population of brainstem neurons which drive swimming in young frog tadpoles. A passive network of 30 multicompartmental neurons with unmyelinated axons was used to infer that: axon-axon gap junctions close to the soma gave the best match to experimentally measured coupling coefficients; axon diameter had a strong influence on coupling; most neurons were coupled indirectly via the axons of other neurons. When active channels were added, gap junctions could make action potential propagation along the thin axons unreliable. Increased sodium and decreased potassium channel densities in the initial axon segment improved action potential propagation. Modelling suggested that the single spike firing to step current injection observed in whole-cell recordings is not a cellular property but a dynamic consequence of shunting resulting from electrical coupling. Without electrical coupling, firing of the population during depolarising current was unsynchronised; with coupling, the population showed synchronous recruitment and rhythmic firing. When activated instead by increasing levels of modelled sensory pathway input, the population without electrical coupling was recruited incrementally to unpatterned activity. However, when coupled, the population was recruited all-or-none at threshold into a rhythmic swimming pattern: the tadpole "decided" to swim. Modelling emphasises uncertainties about fine unmyelinated axon physiology but, when informed by biological data, makes general predictions about gap junctions: locations close to the soma; relatively small numbers; many indirect connections between neurons; cause of action potential propagation failure in fine axons; misleading alteration of intrinsic

  4. Magnetic fields and brain tumour risks in UK electricity supply workers.

    Science.gov (United States)

    Sorahan, T

    2014-04-01

    To investigate whether brain tumour risks are related to occupational exposure to low-frequency magnetic fields. Brain tumour risks experienced by 73 051 employees of the former Central Electricity Generating Board of England and Wales were investigated for the period 1973-2010. All employees were hired in the period 1952-82 and were employed for at least 6 months with some employment in the period 1973-82. Detailed calculations had been performed by others to enable an assessment to be made of exposures to magnetic fields. Poisson regression was used to calculate relative risks (rate ratios) of developing a brain tumour (or glioma or meningioma) for categories of lifetime, distant (lagged) and recent (lugged) exposure. Findings for glioma and for the generality of all brain tumours were unexceptional; risks were close to (or below) unity for all exposure categories and there was no suggestion of risks increasing with cumulative (or recent or distant) magnetic field exposures. There were no statistically significant dose-response effects shown for meningioma, but there was some evidence of elevated risks in the three highest exposure categories for exposures received >10 years ago. This study found no evidence to support the hypothesis that exposure to magnetic fields is a risk factor for gliomas, and the findings are consistent with the hypotheses that both distant and recent magnetic field exposures are not causally related to gliomas. The limited positive findings for meningioma may be chance findings; national comparisons argue against a causal interpretation.

  5. [Need-information organization of brain activity].

    Science.gov (United States)

    Simonov, P V

    1979-01-01

    Experimental results and literature data point to the leading role of four brain structures in the genesis of emotional states and in the organization of goal directed behaviour. Owing to the functioning of the frontal parts of the neocortex behaviour is oriented to signals with a high probability of their reinforcement, and owing to the hypothalamus--to satisfaction of the dominant need. Unlike the neocortex the hippocampus is necessary for reactions to signals of lowly probable events, which is typical of emotionally exicted brain. The amygdala complx participates in creation of a balance, a dynamic co-existence between completing needs (motivations) and corresponding emotions. As a result, behaviour becomes more plastic and adequate to the given situation.

  6. The effects of physical activity on brain structure

    Directory of Open Access Journals (Sweden)

    Adam eThomas

    2012-03-01

    Full Text Available Aerobic activity is a powerful stimulus for improving mental health and for generating structural changes in the brain. We review the literature documenting these structural changes and explore exactly where in the brain these changes occur as well as the underlying substrates of the changes including neural, glial, and vasculature components. Aerobic activity has been shown to produce different types of changes in the brain. The presence of novel experiences or learning is an especially important component in how these changes are manifest. We also discuss the distinct time courses of structural brain changes with both aerobic activity and learning as well as how these effects might differ in diseased and elderly groups.

  7. TRANSLATION OF BRAIN ACTIVITY INTO SLEEP

    OpenAIRE

    Krueger, James M.

    2012-01-01

    Cytokines including tumor necrosis factor alpha (TNF) play a role in sleep regulation in health and disease. Hypothalamic and cerebral cortical levels of TNF mRNA or TNF protein have diurnal variations with higher levels associated with greater sleep propensity. Sleep loss is associated with enhanced brain TNF. Central or systemic TNF injections enhance sleep. Inhibition of TNF using the soluble TNF receptor, or anti-TNF antibodies, or a TNF siRNA reduces spontaneous sleep. Mice lacking the T...

  8. Afferent and efferent activity control in the design of brain computer interfaces for motor rehabilitation.

    Science.gov (United States)

    Cho, Woosang; Vidaurre, Carmen; Hoffmann, Ulrich; Birbaumer, Niels; Ramos-Murguialday, Ander

    2011-01-01

    Stroke is a cardiovascular accident within the brain resulting in motor and sensory impairment in most of the survivors. A stroke can produce complete paralysis of the limb although sensory abilities are normally preserved. Functional electrical stimulation (FES), robotics and brain computer interfaces (BCIs) have been used to induce motor rehabilitation. In this work we measured the brain activity of healthy volunteers using electroencephalography (EEG) during FES, passive movements, active movements, motor imagery of the hand and resting to compare afferent and efferent brain signals produced during these motor related activities and to define possible features for an online FES-BCI. In the conditions in which the hand was moved we limited the movement range in order to control the afferent flow. Although we observed that there is a subject dependent frequency and spatial distribution of efferent and afferent signals, common patterns between conditions and subjects were present mainly in the low beta frequency range. When averaging all the subjects together the most significant frequency bin comparing each condition versus rest was exactly the same for all conditions but motor imagery. These results suggest that to implement an on-line FES-BCI, afferent brain signals resulting from FES have to be filtered and time-frequency-spatial features need to be used.

  9. Coherence of brain electrical activity: a quality of life indicator in Alzheimer’s disease?Coerência da atividade elétrica cerebral: indicador da qualidade de vida na doença de Alzheimer?

    Directory of Open Access Journals (Sweden)

    Lineu Corrêa Fonseca

    2015-05-01

    Full Text Available Objective To investigate the relationships between quality of life (QOL and clinical and electroencephalogram (EEG aspects in patients with Alzheimer’s disease (AD. Method Twenty-eight patients with mild or moderate AD, 31 with Parkinson’s disease (PD, and 27 normal controls (NC were submitted to: CERAD neuropsychological battery, Hamilton Depression and Anxiety Rating Scales, Functional Activities Questionnaire, QOL scale for patients with AD, and quantitative EEG measures. Results AD and PD patients had similar QOL (31.0 ± 5.8; 31.7 ± 4.8, respectively, worse than that of NC (37.5 ± 6.3. AD patients had lower global interhemispheric theta coherence (0.49 ± 0.04; 0.52 ± 0.05; 0.52 ± 0.05; respectively than PD and NC. Multiple linear regression for QOL of AD patients revealed that global interhemispheric theta coherence, and Hamilton depression scores were significant factors (coefficients; 58.2 and -0.27, respectively; R2, 0.377. Conclusion Interhemispheric coherence correlates with QOL regardless of cognitive and functional variables and seems to be a neurophysiological indicator of QOL in AD patients.

  10. The Event-Related Brain Potential as an Index of Information Processing and Cognitive Activity: A Program of Basic Research.

    Science.gov (United States)

    1986-02-20

    microscopic and Sonar images, has been applied to ERP data by Duffy and his colleagues (Duffy, Bartels, & Burchfiel, 1981; Duffy, Burchfiel, & Lombroso ...1981, 51: 455-462. Duffy, F.H., Burchfiel, J.L., & Lombroso , C.T. Brain electrical activity mapping (BEAM): a new method for extending the clinical

  11. Brain activity during complex imagined gait tasks in Parkinson disease.

    Science.gov (United States)

    Peterson, Daniel S; Pickett, Kristen A; Duncan, Ryan P; Perlmutter, Joel S; Earhart, Gammon M

    2014-05-01

    Motor imagery during functional magnetic resonance imaging (fMRI) allows assessment of brain activity during tasks, like walking, that cannot be completed in an MRI scanner. We used gait imagery to assess the neural pathophysiology of locomotion in Parkinson disease (PD). Brain activity was measured in five locomotor regions (supplementary motor area (SMA), globus pallidus (GP), putamen, mesencephalic locomotor region, cerebellar locomotor region) during simple (forward) and complex (backward, turning) gait imagery. Brain activity was correlated to overground walking velocity. Across tasks, PD exhibited reduced activity in the globus pallidus compared to controls. People with PD, but not controls, exhibited more activity in the SMA during imagined turning compared to forward or backward walking. In PD, walking speed was correlated to brain activity in several regions. Altered SMA activity in PD during imagined turning may represent compensatory neural adaptations during complex gait. The lowered activity and positive correlation to locomotor function in GP suggests reduced activity in this region may relate to locomotor dysfunction. This study elucidates changes in neural activity during gait in PD, underscoring the importance of testing simple and complex tasks. Results support a positive relationship between activity in locomotor regions and walking ability. Copyright © 2013 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  12. Emotion regulation modulates anticipatory brain activity that predicts emotional memory encoding in women.

    Science.gov (United States)

    Galli, Giulia; Griffiths, Victoria A; Otten, Leun J

    2014-03-01

    It has been shown that the effectiveness with which unpleasant events are encoded into memory is related to brain activity set in train before the events. Here, we assessed whether encoding-related activity before an aversive event can be modulated by emotion regulation. Electrical brain activity was recorded from the scalps of healthy women while they performed an incidental encoding task on randomly intermixed unpleasant and neutral visual scenes. A cue presented 1.5 s before each picture indicated the upcoming valence. In half of the blocks of trials, the instructions emphasized to let emotions arise in a natural way. In the other half, participants were asked to decrease their emotional response by adopting the perspective of a detached observer. Memory for the scenes was probed 1 day later with a recognition memory test. Brain activity before unpleasant scenes predicted later memory of the scenes, but only when participants felt their emotions and did not detach from them. The findings indicate that emotion regulation can eliminate the influence of anticipatory brain activity on memory encoding. This may be relevant for the understanding and treatment of psychiatric diseases with a memory component.

  13. [Study on dewatering of activated sludge under applied electric field].

    Science.gov (United States)

    Ji, Xue-Yuan; Wang, Yi-Li; Feng, Jing

    2012-12-01

    For an electro-dewatering process of activated sludge (AS), the effect of pH and conductivity of AS, flocculation conditioning and operation factors of horizontal electric field (voltage magnitude, method of applying electric field and distance between plates) were investigated, and the corresponding optimum electro-dewatering conditions were also obtained. The results showed that the best electro-dewatering effect was achieved for AS without change of its pH value (6.93) and conductivity (1.46 mS x cm(-1)). CPAM conditioning could lead to the increase of 30%-40% in the dewatering rate and accelerate the dewatering process, whereas a slight increase in the electro-dewatering rate. The electro-dewatering rate for conditioned AS reached 83.12% during an electric field applied period of 60 minutes, while this rate for original AS could be 75.31% even the electric field applied period extended to 120 minutes. The delay of applying the electric field had an inhibition effect on the AS electro-dewatering rate. Moreover, the optimum conditions for AS electro-dewatering were followed: CPAM dose of 9 g x kg(-1), electric field strength of 600 V x m(-1), distance between the two plates of 40 mm, dehydration time of 60 minutes. Under above optimum conditions the AS electro-dewatering rate could approach to 85.33% and the moisture content in AS decreased from 99.30% to 95.15% accordingly.

  14. Non-Invasive Electrical Brain Stimulation Montages for Modulation of Human Motor Function.

    Science.gov (United States)

    Curado, Marco; Fritsch, Brita; Reis, Janine

    2016-02-04

    Non-invasive electrical brain stimulation (NEBS) is used to modulate brain function and behavior, both for research and clinical purposes. In particular, NEBS can be applied transcranially either as direct current stimulation (tDCS) or alternating current stimulation (tACS). These stimulation types exert time-, dose- and in the case of tDCS polarity-specific effects on motor function and skill learning in healthy subjects. Lately, tDCS has been used to augment the therapy of motor disabilities in patients with stroke or movement disorders. This article provides a step-by-step protocol for targeting the primary motor cortex with tDCS and transcranial random noise stimulation (tRNS), a specific form of tACS using an electrical current applied randomly within a pre-defined frequency range. The setup of two different stimulation montages is explained. In both montages the emitting electrode (the anode for tDCS) is placed on the primary motor cortex of interest. For unilateral motor cortex stimulation the receiving electrode is placed on the contralateral forehead while for bilateral motor cortex stimulation the receiving electrode is placed on the opposite primary motor cortex. The advantages and disadvantages of each montage for the modulation of cortical excitability and motor function including learning are discussed, as well as safety, tolerability and blinding aspects.

  15. A pioneer work on electric brain stimulation in psychotic patients. Rudolph Gottfried Arndt and his 1870s studies.

    Science.gov (United States)

    Steinberg, Holger

    2013-07-01

    Today's brain stimulation methods are commonly traced back historically to surgical brain operations. With this one-sided historical approach it is easy to overlook the fact that non-surgical electrical brain-stimulating applications preceded present-day therapies. The first study on transcranial electrical brain stimulation for the treatment of severe mental diseases in a larger group of patients was carried out in the 1870s. Between 1870 and 1878 German psychiatrist Rudolph Gottfried Arndt published the results of his studies in three reports. These are contextualized with contemporary developments of the time, focusing in particular on the (neuro-) sciences. As was common practice at the time, Arndt basically reported individual cases in which electricity was applied to treat severe psychoses with depressive symptoms or even catatonia, hypochondriac delusion and melancholia. Despite their lengthiness, there is frequently a lack of precise physical data on the application of psychological-psychopathological details. Only his 1878 report includes general rules for electrical brain stimulation. Despite their methodological shortcomings and lack of precise treatment data impeding exact understanding, Arndt's studies are pioneering works in the field of electric brain stimulation with psychoses and its positive impacts. Today's transcranial direct current stimulation, and partly vagus nerve stimulation, can be compared with Arndt's methods. Although Arndt's only tangible results were indications for the application of faradic electricity (for inactivity, stupor, weakness and manic depressions) and galvanic current (for affective disorders and psychoses), a historiography of present-day brain stimulation therapies should no longer neglect studies on electrotherapy published in German and international psychiatric and neurological journals and monographs in the 1870s and 1880s. Copyright © 2013 Elsevier Inc. All rights reserved.

  16. Brain Activity Monitoring for Assessing Satisfaction

    Directory of Open Access Journals (Sweden)

    Paola Johanna Rodríguez Carrillo

    2015-06-01

    Full Text Available Satisfaction is a dimension of usability for which quantitative metrics cannot be calculated during user interactions. Measurement is subjective and depends on the ability to interpret questionnaires and on the memory of the user. This paper represents an attempt to develop an automatic quantitative metric of satisfaction, developed using a Brain Computer Interface to monitor the mental states (Attention/Meditation of users. Based on these results, we are able to establish a correlation between the state of Attention and the users' level of satisfaction.

  17. Extracellular electrical activity from the photoreceptors of midge

    Indian Academy of Sciences (India)

    The ontogeny of photosensitivity has been studied in a holometabolous insect, the midge Chironomus ramosus. The life cycle of midges shifts from an aquatic environment to a non-aquatic environment. Extracellular electrical activity of photoreceptor organs was recorded at larval and adult stages. We found an increase in ...

  18. Electrically active sodium-related defect centres in silicon

    DEFF Research Database (Denmark)

    Dahl, Espen; Madsbøll, J.; Søiland, A.-K.

    2013-01-01

    Electrically active defect centres related to sodium in silicon have been examined with deep level transient spectroscopy, and their recombination potential analysed with the microwave photoconductive decay technique. In order to investigate the entire silicon band gap for defect centres, both p-...

  19. On the relation between complex brain activity and consciousness

    OpenAIRE

    Schartner, Michael Manfred

    2017-01-01

    Why does it feel like something to be awake? I.e. how is consciousness generated by the body, the brain in particular? Seeking to map phenomenological properties of any first person experience to neural activity patterns, theories of consciousness suggest a correlation between a specific type of neural dynamical complexity and the level of consciousness: When awake and aware, all brain regions are to a certain extent connected and there is diversity in the interactions. In support of this, Ca...

  20. The effect of physical activity on the brain derived neurotrophic factor: from animal to human studies.

    Science.gov (United States)

    Zoladz, J A; Pilc, A

    2010-10-01

    It is well documented that physical activity can induce a number of various stimuli which are able to enhance the strength and endurance performance of muscles. Moreover, regular physical activity can preserve or delay the appearance of several metabolic disorders in the human body. Physical exercise is also known to enhance the mood and cognitive functions of active people, although the physiological backgrounds of these effects remain unclear. In recent years, since the pioneering study in the past showed that physical activity increases the expression of the brain derived neurothophic factor (BDNF) in the rat brain, a number of studies were undertaken in order to establish the link between that neurothrophin and post-exercise enhancement of mood and cognitive functions in humans. It was recently demonstrated that physical exercise can increase plasma and/or serum BDNF concentration in humans. It was also reported that physical exercise or electrical stimulation can increase the BDNF expression in the skeletal muscles. In the present review, we report the current state of research concerning the effect of a single bout of exercise and training on the BDNF expression in the brain, in both the working muscles as well as on its concentrations in the blood. We have concluded that there may be potential benefits of the exercise-induced enhancement of the BDNF expression and release in the brain as well as in the peripheral tissues, resulting in the improvement of the functioning of the body, although this effect, especially in humans, requires more research.

  1. The electrical activity of stacking faults in Czochralski silicon

    Science.gov (United States)

    Castaldini, A.; Cavallini, A.; Poggi, A.; Susi, E.

    1989-05-01

    A spectroscopic analysis by the light-beam-induced-current technique has been carried out to study the electrical properties of stacking faults in Czochralski silicon subjected to internal gettering treatments. By changing the wavelength of the light beam probing the sample, we have obtained the depth profiling of the stacking fault electrical activity. Occurrence of minority carrier recombination and generation processes at some stacking faults, corresponding, respectively, to dark and bright levels in a grey-shade imaging, has been observed. The presence of fixed charges at the defect-silicon matrix interface is hypothesized as a possible cause of the observed images.

  2. Increased brain activation during working memory processing after pediatric mild traumatic brain injury (mTBI)

    Science.gov (United States)

    Westfall, Daniel R.; West, John D.; Bailey, Jessica N.; Arnold, Todd W.; Kersey, Patrick A.; Saykin, Andrew J.; McDonald, Brenna C.

    2016-01-01

    Purpose The neural substrate of post-concussive symptoms following the initial injury period after mild traumatic brain injury (mTBI) in pediatric populations remains poorly elucidated. This study examined neuropsychological, behavioral, and brain functioning in adolescents post-mTBI to assess whether persistent differences were detectable up to a year post-injury. Methods Nineteen adolescents (mean age 14.7 years) who experienced mTBI 3–12 months previously (mean 7.5 months) and 19 matched healthy controls (mean age 14.0 years) completed neuropsychological testing and an fMRI auditory-verbal N-back working memory task. Parents completed behavioral ratings. Results No between-group differences were found for cognition, behavior, or N-back task performance, though the expected decreased accuracy and increased reaction time as task difficulty increased were apparent. However, the mTBI group showed significantly greater brain activation than controls during the most difficult working memory task condition. Conclusion Greater working memory task-related activation was found in adolescents up to one year post-mTBI relative to controls, potentially indicating compensatory activation to support normal task performance. Differences in brain activation in the mTBI group so long after injury may indicate residual alterations in brain function much later than would be expected based on the typical pattern of natural recovery, which could have important clinical implications. PMID:26684070

  3. On the possibilities of electric power quality control via electric loads with active rectifiers

    Directory of Open Access Journals (Sweden)

    Володимир Володимирович Бурлака

    2017-07-01

    Full Text Available The paper proposes a method for controlling the electric power quality parameters in a distribution network by modifying the control algorithms for electric loads equipped with active rectifiers fed from this network. Thus, by controlling the reactive component of the input current of such rectifiers, it is possible to reduce the voltage fluctuations at the point of common connection (PCC, the efficiency of such a method being higher the higher the X/R ratio of the network is. It is also possible to reduce the voltage harmonics in the PCC by integrating the functions of parallel active filters into active rectifiers. The proposed method allows for limited control over the flow of inactive power in the distribution network, which makes it possible to improve the electric power quality and reduce the required power of the filter compensating devices. The proposed algorithm for controlling the active rectifier is tested on the mathematical model of group loads. A group of high power resistance welding machines (RWMs operating randomly with a normal probability distribution connected to 0,4 kV grid as a non-stationary load is used. The application of the proposed reactive current control method in the RWM power supplies made it possible to reduce the voltage fluctuations in 0,4 kV grid from 12% to 5%.

  4. Disparate effects of training on brain activation in Parkinson disease.

    Science.gov (United States)

    Maidan, Inbal; Rosenberg-Katz, Keren; Jacob, Yael; Giladi, Nir; Hausdorff, Jeffrey M; Mirelman, Anat

    2017-10-24

    To compare the effects of 2 forms of exercise, i.e., a 6-week trial of treadmill training with virtual reality (TT + VR) that targets motor and cognitive aspects of safe ambulation and a 6-week trial of treadmill training alone (TT), on brain activation in patients with Parkinson disease (PD). As part of a randomized controlled trial, patients were randomly assigned to 6 weeks of TT (n = 17, mean age 71.5 ± 1.5 years, disease duration 11.6 ± 1.6 years; 70% men) or TT + VR (n = 17, mean age 71.2 ± 1.7 years, disease duration 7.9 ± 1.4 years; 65% men). A previously validated fMRI imagery paradigm assessed changes in neural activation pretraining and post-training. Participants imagined themselves walking in 2 virtual scenes projected in the fMRI: (1) a clear path and (2) a path with virtual obstacles. Whole brain and region of interest analyses were performed. Brain activation patterns were similar between training arms before the interventions. After training, participants in the TT + VR arm had lower activation than the TT arm in Brodmann area 10 and the inferior frontal gyrus (cluster level familywise error-corrected [FWEcorr] p Exercise modifies brain activation patterns in patients with PD in a mode-specific manner. Motor-cognitive training decreased the reliance on frontal regions, which apparently resulted in improved function, perhaps reflecting increased brain efficiency. © 2017 American Academy of Neurology.

  5. Brain-controlled functional electrical stimulation therapy for gait rehabilitation after stroke: a safety study.

    Science.gov (United States)

    McCrimmon, Colin M; King, Christine E; Wang, Po T; Cramer, Steven C; Nenadic, Zoran; Do, An H

    2015-07-11

    Many stroke survivors have significant long-term gait impairment, often involving foot drop. Current physiotherapies provide limited recovery. Orthoses substitute for ankle strength, but they provide no lasting therapeutic effect. Brain-computer interface (BCI)-controlled functional electrical stimulation (FES) is a novel rehabilitative approach that may generate permanent neurological improvements. This study explores the safety and feasibility of a foot-drop-targeted BCI-FES physiotherapy in chronic stroke survivors. Subjects (n = 9) operated an electroencephalogram-based BCI-FES system for foot dorsiflexion in 12 one-hour sessions over four weeks. Gait speed, dorsiflexion active range of motion (AROM), six-minute walk distance (6MWD), and Fugl-Meyer leg motor (FM-LM) scores were assessed before, during, and after therapy. The primary safety outcome measure was the proportion of subjects that deteriorated in gait speed by ≥0.16 m/s at one week or four weeks post-therapy. The secondary outcome measures were the proportion of subjects that experienced a clinically relevant decrease in dorsiflexion AROM (≥2.5°), 6MWD (≥20 %), and FM-LM score (≥10 %) at either post-therapy assessment. No subjects (0/9) experienced a clinically significant deterioration in gait speed, dorsiflexion AROM, 6MWT distance, or FM-LM score at either post-therapy assessment. Five subjects demonstrated a detectable increase (≥0.06 m/s) in gait speed, three subjects demonstrated a detectable increase (≥2.5°) in dorsiflexion AROM, five subjects demonstrated a detectable increase (≥10 %) in 6MWD, and three subjects demonstrated a detectable increase (≥10 %) in FM-LM. Five of the six subjects that exhibited a detectable increase in either post-therapy gait speed or 6MWD also exhibited significant (p stroke gait function in future studies, it could provide a new gait rehabilitation option for severely impaired patients. Formal clinical trials are warranted.

  6. Uncovering intrinsic modular organization of spontaneous brain activity in humans.

    Directory of Open Access Journals (Sweden)

    Yong He

    Full Text Available The characterization of topological architecture of complex brain networks is one of the most challenging issues in neuroscience. Slow (<0.1 Hz, spontaneous fluctuations of the blood oxygen level dependent (BOLD signal in functional magnetic resonance imaging are thought to be potentially important for the reflection of spontaneous neuronal activity. Many studies have shown that these fluctuations are highly coherent within anatomically or functionally linked areas of the brain. However, the underlying topological mechanisms responsible for these coherent intrinsic or spontaneous fluctuations are still poorly understood. Here, we apply modern network analysis techniques to investigate how spontaneous neuronal activities in the human brain derived from the resting-state BOLD signals are topologically organized at both the temporal and spatial scales. We first show that the spontaneous brain functional networks have an intrinsically cohesive modular structure in which the connections between regions are much denser within modules than between them. These identified modules are found to be closely associated with several well known functionally interconnected subsystems such as the somatosensory/motor, auditory, attention, visual, subcortical, and the "default" system. Specifically, we demonstrate that the module-specific topological features can not be captured by means of computing the corresponding global network parameters, suggesting a unique organization within each module. Finally, we identify several pivotal network connectors and paths (predominantly associated with the association and limbic/paralimbic cortex regions that are vital for the global coordination of information flow over the whole network, and we find that their lesions (deletions critically affect the stability and robustness of the brain functional system. Together, our results demonstrate the highly organized modular architecture and associated topological properties in

  7. Long-duration transcutaneous electric acupoint stimulation alters small-world brain functional networks.

    Science.gov (United States)

    Zhang, Yue; Jiang, Yin; Glielmi, Christopher B; Li, Longchuan; Hu, Xiaoping; Wang, Xiaoying; Han, Jisheng; Zhang, Jue; Cui, Cailian; Fang, Jing

    2013-09-01

    Acupuncture, which is recognized as an alternative and complementary treatment in Western medicine, has long shown efficiencies in chronic pain relief, drug addiction treatment, stroke rehabilitation and other clinical practices. The neural mechanism underlying acupuncture, however, is still unclear. Many studies have focused on the sustained effects of acupuncture on healthy subjects, yet there are very few on the topological organization of functional networks in the whole brain in response to long-duration acupuncture (longer than 20 min). This paper presents a novel study on the effects of long-duration transcutaneous electric acupoint stimulation (TEAS) on the small-world properties of brain functional networks. Functional magnetic resonance imaging was used to construct brain functional networks of 18 healthy subjects (9 males and 9 females) during the resting state. All subjects received both TEAS and minimal TEAS (MTEAS) and were scanned before and after each stimulation. An altered functional network was found with lower local efficiency and no significant change in global efficiency for healthy subjects after TEAS, while no significant difference was observed after MTEAS. The experiments also showed that the nodal efficiencies in several paralimbic/limbic regions were altered by TEAS, and those in middle frontal gyrus and other regions by MTEAS. To remove the psychological effects and the baseline, we compared the difference between diffTEAS (difference between after and before TEAS) and diffMTEAS (difference between after and before MTEAS). The results showed that the local efficiency was decreased and that the nodal efficiencies in frontal gyrus, orbitofrontal cortex, anterior cingulate gyrus and hippocampus gyrus were changed. Based on those observations, we conclude that long-duration TEAS may modulate the short-range connections of brain functional networks and also the limbic system. Copyright © 2013 Elsevier Inc. All rights reserved.

  8. Evaluation of the Electrical Resistance and Capacitance of a Di-Electric Electro-Active Polymer

    Science.gov (United States)

    Ng, Boon Chai; Lovhoiden, Gunnar; Magbanua, James

    Dielectric Electro Active Polymers (DEAP) have the potential of converting mechanical energy into electrical energy. DEAP consists of a silicone dielectric film material with a special corrugated surface and a very thin layer of metallic electrodes on both sides of the surface allowing for large mechanical deformations with low operating forces. This work examined how the DEAP capacitance and the electrode resistance were affected by repeated stress relaxation cycles.

  9. Brain network activity in monolingual and bilingual older adults.

    Science.gov (United States)

    Grady, Cheryl L; Luk, Gigi; Craik, Fergus I M; Bialystok, Ellen

    2015-01-01

    Bilingual older adults typically have better performance on tasks of executive control (EC) than do their monolingual peers, but differences in brain activity due to language experience are not well understood. Based on studies showing a relation between the dynamic range of brain network activity and performance on EC tasks, we hypothesized that life-long bilingual older adults would show increased functional connectivity relative to monolinguals in networks related to EC. We assessed intrinsic functional connectivity and modulation of activity in task vs. fixation periods in two brain networks that are active when EC is engaged, the frontoparietal control network (FPC) and the salience network (SLN). We also examined the default mode network (DMN), which influences behavior through reduced activity during tasks. We found stronger intrinsic functional connectivity in the FPC and DMN in bilinguals than in monolinguals. Although there were no group differences in the modulation of activity across tasks and fixation, bilinguals showed stronger correlations than monolinguals between intrinsic connectivity in the FPC and task-related increases of activity in prefrontal and parietal regions. This bilingual difference in network connectivity suggests that language experience begun in childhood and continued throughout adulthood influences brain networks in ways that may provide benefits in later life. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Spontaneous brain activity predicts learning ability of foreign sounds.

    Science.gov (United States)

    Ventura-Campos, Noelia; Sanjuán, Ana; González, Julio; Palomar-García, María-Ángeles; Rodríguez-Pujadas, Aina; Sebastián-Gallés, Núria; Deco, Gustavo; Ávila, César

    2013-05-29

    Can learning capacity of the human brain be predicted from initial spontaneous functional connectivity (FC) between brain areas involved in a task? We combined task-related functional magnetic resonance imaging (fMRI) and resting-state fMRI (rs-fMRI) before and after training with a Hindi dental-retroflex nonnative contrast. Previous fMRI results were replicated, demonstrating that this learning recruited the left insula/frontal operculum and the left superior parietal lobe, among other areas of the brain. Crucially, resting-state FC (rs-FC) between these two areas at pretraining predicted individual differences in learning outcomes after distributed (Experiment 1) and intensive training (Experiment 2). Furthermore, this rs-FC was reduced at posttraining, a change that may also account for learning. Finally, resting-state network analyses showed that the mechanism underlying this reduction of rs-FC was mainly a transfer in intrinsic activity of the left frontal operculum/anterior insula from the left frontoparietal network to the salience network. Thus, rs-FC may contribute to predict learning ability and to understand how learning modifies the functioning of the brain. The discovery of this correspondence between initial spontaneous brain activity in task-related areas and posttraining performance opens new avenues to find predictors of learning capacities in the brain using task-related fMRI and rs-fMRI combined.

  11. Experimental evaluation of electrical conductivity imaging of anisotropic brain tissues using a combination of diffusion tensor imaging and magnetic resonance electrical impedance tomography

    Directory of Open Access Journals (Sweden)

    Saurav Z. K. Sajib

    2016-06-01

    Full Text Available Anisotropy of biological tissues is a low-frequency phenomenon that is associated with the function and structure of cell membranes. Imaging of anisotropic conductivity has potential for the analysis of interactions between electromagnetic fields and biological systems, such as the prediction of current pathways in electrical stimulation therapy. To improve application to the clinical environment, precise approaches are required to understand the exact responses inside the human body subjected to the stimulated currents. In this study, we experimentally evaluate the anisotropic conductivity tensor distribution of canine brain tissues, using a recently developed diffusion tensor-magnetic resonance electrical impedance tomography method. At low frequency, electrical conductivity of the biological tissues can be expressed as a product of the mobility and concentration of ions in the extracellular space. From diffusion tensor images of the brain, we can obtain directional information on diffusive movements of water molecules, which correspond to the mobility of ions. The position dependent scale factor, which provides information on ion concentration, was successfully calculated from the magnetic flux density, to obtain the equivalent conductivity tensor. By combining the information from both techniques, we can finally reconstruct the anisotropic conductivity tensor images of brain tissues. The reconstructed conductivity images better demonstrate the enhanced signal intensity in strongly anisotropic brain regions, compared with those resulting from previous methods using a global scale factor.

  12. Experimental evaluation of electrical conductivity imaging of anisotropic brain tissues using a combination of diffusion tensor imaging and magnetic resonance electrical impedance tomography

    Energy Technology Data Exchange (ETDEWEB)

    Sajib, Saurav Z. K.; Jeong, Woo Chul; Oh, Tong In; Kim, Hyung Joong, E-mail: bmekim@khu.ac.kr, E-mail: ejwoo@khu.ac.kr; Woo, Eung Je, E-mail: bmekim@khu.ac.kr, E-mail: ejwoo@khu.ac.kr [Department of Biomedical Engineering, Kyung Hee University, Seoul 02447 (Korea, Republic of); Kyung, Eun Jung [Department of Pharmacology, Chung-Ang University, Seoul 06974 (Korea, Republic of); Kim, Hyun Bum [Department of East-West Medical Science, Kyung Hee University, Yongin 17104 (Korea, Republic of); Kwon, Oh In [Department of Mathematics, Konkuk University, Seoul 05029 (Korea, Republic of)

    2016-06-15

    Anisotropy of biological tissues is a low-frequency phenomenon that is associated with the function and structure of cell membranes. Imaging of anisotropic conductivity has potential for the analysis of interactions between electromagnetic fields and biological systems, such as the prediction of current pathways in electrical stimulation therapy. To improve application to the clinical environment, precise approaches are required to understand the exact responses inside the human body subjected to the stimulated currents. In this study, we experimentally evaluate the anisotropic conductivity tensor distribution of canine brain tissues, using a recently developed diffusion tensor-magnetic resonance electrical impedance tomography method. At low frequency, electrical conductivity of the biological tissues can be expressed as a product of the mobility and concentration of ions in the extracellular space. From diffusion tensor images of the brain, we can obtain directional information on diffusive movements of water molecules, which correspond to the mobility of ions. The position dependent scale factor, which provides information on ion concentration, was successfully calculated from the magnetic flux density, to obtain the equivalent conductivity tensor. By combining the information from both techniques, we can finally reconstruct the anisotropic conductivity tensor images of brain tissues. The reconstructed conductivity images better demonstrate the enhanced signal intensity in strongly anisotropic brain regions, compared with those resulting from previous methods using a global scale factor.

  13. Visceral Inflammation and Immune Activation Stress the Brain

    Science.gov (United States)

    Holzer, Peter; Farzi, Aitak; Hassan, Ahmed M.; Zenz, Geraldine; Jačan, Angela; Reichmann, Florian

    2017-01-01

    Stress refers to a dynamic process in which the homeostasis of an organism is challenged, the outcome depending on the type, severity, and duration of stressors involved, the stress responses triggered, and the stress resilience of the organism. Importantly, the relationship between stress and the immune system is bidirectional, as not only stressors have an impact on immune function, but alterations in immune function themselves can elicit stress responses. Such bidirectional interactions have been prominently identified to occur in the gastrointestinal tract in which there is a close cross-talk between the gut microbiota and the local immune system, governed by the permeability of the intestinal mucosa. External stressors disturb the homeostasis between microbiota and gut, these disturbances being signaled to the brain via multiple communication pathways constituting the gut–brain axis, ultimately eliciting stress responses and perturbations of brain function. In view of these relationships, the present article sets out to highlight some of the interactions between peripheral immune activation, especially in the visceral system, and brain function, behavior, and stress coping. These issues are exemplified by the way through which the intestinal microbiota as well as microbe-associated molecular patterns including lipopolysaccharide communicate with the immune system and brain, and the mechanisms whereby overt inflammation in the GI tract impacts on emotional-affective behavior, pain sensitivity, and stress coping. The interactions between the peripheral immune system and the brain take place along the gut–brain axis, the major communication pathways of which comprise microbial metabolites, gut hormones, immune mediators, and sensory neurons. Through these signaling systems, several transmitter and neuropeptide systems within the brain are altered under conditions of peripheral immune stress, enabling adaptive processes related to stress coping and resilience

  14. Traumatic Brain Injury Increases Cortical Glutamate Network Activity by Compromising GABAergic Control.

    Science.gov (United States)

    Cantu, David; Walker, Kendall; Andresen, Lauren; Taylor-Weiner, Amaro; Hampton, David; Tesco, Giuseppina; Dulla, Chris G

    2015-08-01

    Traumatic brain injury (TBI) is a major risk factor for developing pharmaco-resistant epilepsy. Although disruptions in brain circuitry are associated with TBI, the precise mechanisms by which brain injury leads to epileptiform network activity is unknown. Using controlled cortical impact (CCI) as a model of TBI, we examined how cortical excitability and glutamatergic signaling was altered following injury. We optically mapped cortical glutamate signaling using FRET-based glutamate biosensors, while simultaneously recording cortical field potentials in acute brain slices 2-4 weeks following CCI. Cortical electrical stimulation evoked polyphasic, epileptiform field potentials and disrupted the input-output relationship in deep layers of CCI-injured cortex. High-speed glutamate biosensor imaging showed that glutamate signaling was significantly increased in the injured cortex. Elevated glutamate responses correlated with epileptiform activity, were highest directly adjacent to the injury, and spread via deep cortical layers. Immunoreactivity for markers of GABAergic interneurons were significantly decreased throughout CCI cortex. Lastly, spontaneous inhibitory postsynaptic current frequency decreased and spontaneous excitatory postsynaptic current increased after CCI injury. Our results suggest that specific cortical neuronal microcircuits may initiate and facilitate the spread of epileptiform activity following TBI. Increased glutamatergic signaling due to loss of GABAergic control may provide a mechanism by which TBI can give rise to post-traumatic epilepsy. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  15. Traumatic Brain Injury Increases Cortical Glutamate Network Activity by Compromising GABAergic Control

    Science.gov (United States)

    Cantu, David; Walker, Kendall; Andresen, Lauren; Taylor-Weiner, Amaro; Hampton, David; Tesco, Giuseppina; Dulla, Chris G.

    2015-01-01

    Traumatic brain injury (TBI) is a major risk factor for developing pharmaco-resistant epilepsy. Although disruptions in brain circuitry are associated with TBI, the precise mechanisms by which brain injury leads to epileptiform network activity is unknown. Using controlled cortical impact (CCI) as a model of TBI, we examined how cortical excitability and glutamatergic signaling was altered following injury. We optically mapped cortical glutamate signaling using FRET-based glutamate biosensors, while simultaneously recording cortical field potentials in acute brain slices 2–4 weeks following CCI. Cortical electrical stimulation evoked polyphasic, epileptiform field potentials and disrupted the input–output relationship in deep layers of CCI-injured cortex. High-speed glutamate biosensor imaging showed that glutamate signaling was significantly increased in the injured cortex. Elevated glutamate responses correlated with epileptiform activity, were highest directly adjacent to the injury, and spread via deep cortical layers. Immunoreactivity for markers of GABAergic interneurons were significantly decreased throughout CCI cortex. Lastly, spontaneous inhibitory postsynaptic current frequency decreased and spontaneous excitatory postsynaptic current increased after CCI injury. Our results suggest that specific cortical neuronal microcircuits may initiate and facilitate the spread of epileptiform activity following TBI. Increased glutamatergic signaling due to loss of GABAergic control may provide a mechanism by which TBI can give rise to post-traumatic epilepsy. PMID:24610117

  16. Abnormal Brain Activation During Inhibition and Error Detection in Medication-Naive Adolescents With ADHD

    National Research Council Canada - National Science Library

    Rubia, Katya; Smith, Anna B; Brammer, Michael J; Toone, Brian; Taylor, Eric

    2005-01-01

    OBJECTIVE: Patients with attention deficit hyperactivity disorder (ADHD) and a medication history have shown abnormal brain activation in prefrontal and striatal brain regions during cognitive challenge...

  17. Electrical conductivity and permittivity maps of brain tissues derived from water content based on T1 -weighted acquisition.

    Science.gov (United States)

    Michel, Eric; Hernandez, Daniel; Lee, Soo Yeol

    2017-03-01

    To develop an electrical properties tomography (EPT) technique that can provide in vivo electrical conductivity and permittivity images of biological tissue without performing complex-valued radiofrequency field measurements. Electrical conductivity and permittivity images are modeled as a monotonic function of tissues' water content (W) under the principle of Maxwell's mixture theory. Water content maps are estimated from two spin-echo images having different repetition times (TRs). For the modeling functions, physically measured parameters (electrical properties, water content, and T1 ) of brain cerebrospinal fluid (CSF), gray matter, and white matter are used as landmark literature references. The formulations are validated by a developed electrolyte-protein phantom and by human brain studies at 3 Tesla (T). The electrical properties (EPs) of the phantom estimated by the proposed method match well with the values measured on the bench. The conductivity and permittivity maps from all experiments show uncompromised spatial resolution without boundary artifacts and higher contrast when compared with water content maps. Human brain and phantom EP images suggest that water content is a dominating factor in determining the electrical properties of tissues. Despite possible literature inaccuracies, the proposed method offers EP maps that can provide complementary information to current approaches, to facilitate EPT scans in clinical applications. Magn Reson Med 77:1094-1103, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

  18. [Functional asymmetry of electric processes in the rabbit brain cortex at formation of the hunger dominant].

    Science.gov (United States)

    Rusinova, E V

    2011-01-01

    The motivational condition of hunger and formation of the hunger dominant after daily food deprivation was studied in the conditions of chronic experiments on rabbits. It was shown, that the hunger condition was accompanied by left sided interhemispher asymmetry on indicators of spectral capacity of EEG frontal and right-hand asymmetry sensorimotor areas of the cortex. A hunger dominant was accompanied by falling of spectral capacity of EEG of areas of both hemispheres. The condition of hunger and a hunger dominant were characterized by right-hand asymmetry on average level of EEG coherence of frontal and sensorimotor areas. At transition of a condition of hunger in a hunger dominant there was an average level of EEG coherence decrease in areas of the right hemisphere. Electric processes of the cortex of the brain at a motivational condition of hunger and a hunger dominant were different.

  19. Functional asymmetry between the left and right human fusiform gyrus explored through electrical brain stimulation.

    Science.gov (United States)

    Rangarajan, Vinitha; Parvizi, Josef

    2016-03-01

    The ventral temporal cortex (VTC) contains several areas with selective responses to words, numbers, faces, and objects as demonstrated by numerous human and primate imaging and electrophysiological studies. Our recent work using electrocorticography (ECoG) confirmed the presence of face-selective neuronal populations in the human fusiform gyrus (FG) in patients implanted with intracranial electrodes in either the left or right hemisphere. Electrical brain stimulation (EBS) disrupted the conscious perception of faces only when it was delivered in the right, but not left, FG. In contrast to our previous findings, here we report both negative and positive EBS effects in right and left FG, respectively. The presence of right hemisphere language dominance in the first, and strong left-handedness and poor language processing performance in the second case, provide indirect clues about the functional architecture of the human VTC in relation to hemispheric asymmetries in language processing and handedness. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. The active electric sense of weakly electric fish: from electric organ discharge to sensory processing and behaviour

    Directory of Open Access Journals (Sweden)

    Krahe Rüdiger

    2016-01-01

    Full Text Available Sensory systems have been shaped by evolution to extract information that is relevant for decision making. In order to understand the mechanisms used by sensory systems for filtering the incoming stream of sensory input, it is important to have a quantitative understanding of the natural sensory scenes that are to be processed. Weakly electric fish lead a rather cryptic nocturnal life in often turbid tropical rainforest streams. They produce electric discharges and sense perturbations of their selfgenerated electric field for prey detection and navigation, and also use their active sense for communication in the context of courtship and aggression. The fact that they produce their electric signals throughout day and night permits the use of electrode arrays to track the movements of multiple individual fish and monitor their communication interactions, thus offering a window into their electrosensory world. This approach yields unprecedented access to information on the biology of these fishes and also on the statistical properties of the sensory scenes that are to be processed by their electrosensory system. The electrosensory system shares many organizational features with other sensory systems, in particular, the use of multiple topographic maps. In fact, the sensory surface (the skin is represented in three parallel maps in the hindbrain, with each map covering the receptor organ array with six different cell types that project to the next higher level of processing. Thus, the electroreceptive body surface is represented a total of 18 times in the hindbrain, with each representation having its specific filter properties and degree of response plasticity. Thus, the access to the sensory world of these fish as well as the manifold filtering of the sensory input makes these fish an excellent model system for exploring the cell-intrinsic and network characteristics underlying the extraction of behaviourally relevant sensory information.

  1. Model of electrical activity in cardiac tissue under electromagnetic induction.

    Science.gov (United States)

    Wu, Fuqiang; Wang, Chunni; Xu, Ying; Ma, Jun

    2016-12-23

    Complex electrical activities in cardiac tissue can set up time-varying electromagnetic field. Magnetic flux is introduced into the Fitzhugh-Nagumo model to describe the effect of electromagnetic induction, and then memristor is used to realize the feedback of magnetic flux on the membrane potential in cardiac tissue. It is found that a spiral wave can be triggered and developed by setting specific initials in the media, that is to say, the media still support the survival of standing spiral waves under electromagnetic induction. Furthermore, electromagnetic radiation is considered on this model as external stimuli, it is found that spiral waves encounter breakup and turbulent electrical activities are observed, and it can give guidance to understand the occurrence of sudden heart disorder subjected to heavily electromagnetic radiation.

  2. Simulated driving and brain imaging: combining behavior, brain activity, and virtual reality.

    Science.gov (United States)

    Carvalho, Kara N; Pearlson, Godfrey D; Astur, Robert S; Calhoun, Vince D

    2006-01-01

    Virtual reality in the form of simulated driving is a useful tool for studying the brain. Various clinical questions can be addressed, including both the role of alcohol as a modulator of brain function and regional brain activation related to elements of driving. We reviewed a study of the neural correlates of alcohol intoxication through the use of a simulated-driving paradigm and wished to demonstrate the utility of recording continuous-driving behavior through a new study using a programmable driving simulator developed at our center. Functional magnetic resonance imaging data was collected from subjects while operating a driving simulator. Independent component analysis (ICA) was used to analyze the data. Specific brain regions modulated by alcohol, and relationships between behavior, brain function, and alcohol blood levels were examined with aggregate behavioral measures. Fifteen driving epochs taken from two subjects while also recording continuously recorded driving variables were analyzed with ICA. Preliminary findings reveal that four independent components correlate with various aspects of behavior. An increase in braking while driving was found to increase activation in motor areas, while cerebellar areas showed signal increases during steering maintenance, yet signal decreases during steering changes. Additional components and significant findings are further outlined. In summary, continuous behavioral variables conjoined with ICA may offer new insight into the neural correlates of complex human behavior.

  3. Model of brain activation predicts the neural collective influence map of the brain.

    Science.gov (United States)

    Morone, Flaviano; Roth, Kevin; Min, Byungjoon; Stanley, H Eugene; Makse, Hernán A

    2017-04-11

    Efficient complex systems have a modular structure, but modularity does not guarantee robustness, because efficiency also requires an ingenious interplay of the interacting modular components. The human brain is the elemental paradigm of an efficient robust modular system interconnected as a network of networks (NoN). Understanding the emergence of robustness in such modular architectures from the interconnections of its parts is a longstanding challenge that has concerned many scientists. Current models of dependencies in NoN inspired by the power grid express interactions among modules with fragile couplings that amplify even small shocks, thus preventing functionality. Therefore, we introduce a model of NoN to shape the pattern of brain activations to form a modular environment that is robust. The model predicts the map of neural collective influencers (NCIs) in the brain, through the optimization of the influence of the minimal set of essential nodes responsible for broadcasting information to the whole-brain NoN. Our results suggest intervention protocols to control brain activity by targeting influential neural nodes predicted by network theory.

  4. Practice induces function-specific changes in brain activity.

    Science.gov (United States)

    van Raalten, Tamar R; Ramsey, Nick F; Duyn, Jeff; Jansma, Johan M

    2008-10-01

    Practice can have a profound effect on performance and brain activity, especially if a task can be automated. Tasks that allow for automatization typically involve repeated encoding of information that is paired with a constant response. Much remains unknown about the effects of practice on encoding and response selection in an automated task. To investigate function-specific effects of automatization we employed a variant of a Sternberg task with optimized separation of activity associated with encoding and response selection by means of m-sequences. This optimized randomized event-related design allows for model free measurement of BOLD signals over the course of practice. Brain activity was measured at six consecutive runs of practice and compared to brain activity in a novel task. Prompt reductions were found in the entire cortical network involved in encoding after a single run of practice. Changes in the network associated with response selection were less robust and were present only after the third run of practice. This study shows that automatization causes heterogeneous decreases in brain activity across functional regions that do not strictly track performance improvement. This suggests that cognitive performance is supported by a dynamic allocation of multiple resources in a distributed network. Our findings may bear importance in understanding the role of automatization in complex cognitive performance, as increased encoding efficiency in early stages of practice possibly increases the capacity to otherwise interfering information.

  5. Practice induces function-specific changes in brain activity.

    Directory of Open Access Journals (Sweden)

    Tamar R van Raalten

    2008-10-01

    Full Text Available Practice can have a profound effect on performance and brain activity, especially if a task can be automated. Tasks that allow for automatization typically involve repeated encoding of information that is paired with a constant response. Much remains unknown about the effects of practice on encoding and response selection in an automated task.To investigate function-specific effects of automatization we employed a variant of a Sternberg task with optimized separation of activity associated with encoding and response selection by means of m-sequences. This optimized randomized event-related design allows for model free measurement of BOLD signals over the course of practice. Brain activity was measured at six consecutive runs of practice and compared to brain activity in a novel task.Prompt reductions were found in the entire cortical network involved in encoding after a single run of practice. Changes in the network associated with response selection were less robust and were present only after the third run of practice.This study shows that automatization causes heterogeneous decreases in brain activity across functional regions that do not strictly track performance improvement. This suggests that cognitive performance is supported by a dynamic allocation of multiple resources in a distributed network. Our findings may bear importance in understanding the role of automatization in complex cognitive performance, as increased encoding efficiency in early stages of practice possibly increases the capacity to otherwise interfering information.

  6. The effect of electrically activated sodium bicarbonate solution on tomatoes.

    OpenAIRE

    2008-01-01

    Tomato (Lycopersicon esculentum Mill.) is an important commercial crop. High quality tomatoes for the local and export markets are grown hydroponically. In this study, the effect of electrically activated sodium bicarbonate and non-ionized sodium bicarbonate solutions on productivity and postharvest quality of hydroponically grown tomatoes was tested. Sodium bicarbonate is a ready source of bicarbonate. By using a novel technique obtained from Radical Waters (Pty) Ltd., ionized bicarbonate (a...

  7. Inferring deep-brain activity from cortical activity using functional near-infrared spectroscopy

    Science.gov (United States)

    Liu, Ning; Cui, Xu; Bryant, Daniel M.; Glover, Gary H.; Reiss, Allan L.

    2015-01-01

    Functional near-infrared spectroscopy (fNIRS) is an increasingly popular technology for studying brain function because it is non-invasive, non-irradiating and relatively inexpensive. Further, fNIRS potentially allows measurement of hemodynamic activity with high temporal resolution (milliseconds) and in naturalistic settings. However, in comparison with other imaging modalities, namely fMRI, fNIRS has a significant drawback: limited sensitivity to hemodynamic changes in deep-brain regions. To overcome this limitation, we developed a computational method to infer deep-brain activity using fNIRS measurements of cortical activity. Using simultaneous fNIRS and fMRI, we measured brain activity in 17 participants as they completed three cognitive tasks. A support vector regression (SVR) learning algorithm was used to predict activity in twelve deep-brain regions using information from surface fNIRS measurements. We compared these predictions against actual fMRI-measured activity using Pearson’s correlation to quantify prediction performance. To provide a benchmark for comparison, we also used fMRI measurements of cortical activity to infer deep-brain activity. When using fMRI-measured activity from the entire cortex, we were able to predict deep-brain activity in the fusiform cortex with an average correlation coefficient of 0.80 and in all deep-brain regions with an average correlation coefficient of 0.67. The top 15% of predictions using fNIRS signal achieved an accuracy of 0.7. To our knowledge, this study is the first to investigate the feasibility of using cortical activity to infer deep-brain activity. This new method has the potential to extend fNIRS applications in cognitive and clinical neuroscience research. PMID:25798327

  8. Brain activation studies with PET and functional MRI

    Energy Technology Data Exchange (ETDEWEB)

    Yonekura, Yoshiharu [Fukui Medical Univ., Matsuoka (Japan). Biomedical Imaging Research Center; Sadato, Norihiro [Okazaki National Research Inst., Aichi (Japan). National Inst. for Physiological Sciences

    2002-01-01

    Application of PET and functional MRI in brain activation studies is reviewed. 3D-PET images obtained repeatedly after intravenous injection of about 370 MBq of H{sub 2}{sup 15}O can detect a faint blood flow change in the brain. Functional MRI can also detect the blood flow change in the brain due to blood oxygen level-dependent effect. Echo-planar imaging is popular in MRI with 1.5 or 3 T. Images are analyzed by statistical parametric mapping with correction of cerebral regions, anatomical normalization and statistics. PET data give the blood flow change by the H{sub 2}{sup 15}O incorporation into the brain and MRI data, by the scarce tissue oxygen consumption despite the change. Actual images during the cognition task-performance and of frequent artifacts are given. PET is suitable for studies of brain functions like sensibility and emotion and functional MRI, like cortex functions and clinical practices in identification of functional regions prior to surgery and evaluation of functional recovery of damaged brain. (K.H.)

  9. Brain activation during micturition in women

    NARCIS (Netherlands)

    Blok, Bertil F.M.; Sturms, Leontien M.; Holstege, Gert

    1998-01-01

    Experiments in the cat have led to a concept of how the CNS controls micturition. In a previous study this concept was tested in a PET study in male volunteers, It was demonstrated that specific brainstem and forebrain areas are activated during micturition, It was unfortunate that this study did

  10. The electric field distribution in the brain during TTFields therapy and its dependence on tissue dielectric properties and anatomy: a computational study

    Science.gov (United States)

    Wenger, Cornelia; Salvador, Ricardo; Basser, Peter J.; Miranda, Pedro C.

    2015-09-01

    Tumor treating fields (TTFields) are a non-invasive, anti-mitotic and approved treatment for recurrent glioblastoma multiforme (GBM) patients. In vitro studies have shown that inhibition of cell division in glioma is achieved when the applied alternating electric field has a frequency in the range of 200 kHz and an amplitude of 1-3 V cm-1. Our aim is to calculate the electric field distribution in the brain during TTFields therapy and to investigate the dependence of these predictions on the heterogeneous, anisotropic dielectric properties used in the computational model. A realistic head model was developed by segmenting MR images and by incorporating anisotropic conductivity values for the brain tissues. The finite element method (FEM) was used to solve for the electric potential within a volume mesh that consisted of the head tissues, a virtual lesion with an active tumour shell surrounding a necrotic core, and the transducer arrays. The induced electric field distribution is highly non-uniform. Average field strength values are slightly higher in the tumour when incorporating anisotropy, by about 10% or less. A sensitivity analysis with respect to the conductivity and permittivity of head tissues shows a variation in field strength of less than 42% in brain parenchyma and in the tumour, for values within the ranges reported in the literature. Comparing results to a previously developed head model suggests significant inter-subject variability. This modelling study predicts that during treatment with TTFields the electric field in the tumour exceeds 1 V cm-1, independent of modelling assumptions. In the future, computational models may be useful to optimize delivery of TTFields.

  11. Fast regulation of axonal growth cone motility by electrical activity.

    Science.gov (United States)

    Ibarretxe, Gaskon; Perrais, David; Jaskolski, Frédéric; Vimeney, Alice; Mulle, Christophe

    2007-07-18

    Axonal growth cones are responsible for the correct guidance of developing axons and the establishment of functional neural networks. They are highly motile because of fast and continuous rearrangements of their actin-rich cytoskeleton. Here we have used live imaging of axonal growth cones of hippocampal neurons in culture and quantified their motility with a temporal resolution of 2 s. Using novel methods of analysis of growth cone dynamics, we show that transient activation of kainate receptors by bath-applied kainate induced a fast and reversible growth cone stalling. This effect depends on electrical activity and can be mimicked by the transient discharge of action potentials elicited in the neuron by intracellular current injections at the somatic level through a patch pipette. Growth cone stalling induced by electrical stimulation is mediated by calcium entry from the extracellular medium as well as by calcium release from intracellular stores that define spatially restricted microdomains directly affecting cytoskeletal dynamics. We propose that growth cone motility is dynamically controlled by transient bursts of spontaneous electrical activity, which constitutes a prominent feature of developing neural networks in vivo.

  12. Social anxiety disorder: radio electric asymmetric conveyor brain stimulation versus sertraline.

    Science.gov (United States)

    Fontani, Vania; Mannu, Piero; Castagna, Alessandro; Rinaldi, Salvatore

    2011-01-01

    Social anxiety disorder (SAD) is a disabling condition that affects almost 5% of the general population. Many types of drugs have shown their efficacy in the treatment of SAD. There are also some data regarding psychotherapies, but no data are available today about the efficacy of brain stimulation techniques. The aim of the study is to compare the efficacy of noninvasive brain stimulation neuro psycho physical optimization (NPPO) protocol performed by radio electric asymmetric conveyor (REAC) with that of sertraline in adults with SAD. Twenty SAD patients on sertraline were compared with 23 SAD patients who refused any drug treatment and who chose to be treated with NPPO-REAC brain stimulation. This was a 6-month, open-label, naturalistic study. Patients on sertraline received flexible doses, whereas NPPO-REAC patients received two 18-session cycles of treatment. Clinical Global Improvement scale items "much improved" or "very much improved" and Liebowitz Social Anxiety Scale total score variation on fear and avoidance components were used to detect the results. The statistical analysis was performed with t-test. All measures <0.05 have been considered statistically significant. Ten of 23 subjects on NPPO-REAC and six of the 20 taking sertraline were much improved or very much improved 1 month after the first NPPO-REAC cycle (t1). Sixteen of the subjects on NPPO-REAC and ten of the subjects taking sertraline were much improved or very much improved 1 month after the second NPPO-REAC cycle (t2). In respect of the Liebowitz Social Anxiety Scale, at t1 NPPO-REAC resulted in statistically more efficacy for sertraline on both fear and avoidance total scores. At t2, NPPO-REAC resulted in statistically more efficacy for sertraline on fear but not on avoidance. NPPO-REAC is an effective treatment for SAD, allowing substantial and clinically meaningful reductions in symptoms and disability in comparison with sertraline.

  13. Active Removal of Large Debris: Electrical Propulsion Capabilities

    Science.gov (United States)

    Billot Soccodato, Carole; Lorand, Anthony; Perrin, Veronique; Couzin, Patrice; FontdecabaBaig, Jordi

    2013-08-01

    The risk for current operational spacecraft or future market induced by large space debris, dead satellites or rocket bodies, in Low Earth Orbit has been identified several years ago. Many potential solutions and architectures are traded with a main objective of reducing cost per debris. Based on cost consideration, specially driven by launch cost, solutions constructed on multi debris capture capacities seem to be much affordable The recent technologic evolutions in electric propulsion and solar power generation can be used to combine high potential vehicles for debris removal. The present paper reports the first results of a study funded by CNES that addresses full electric solutions for large debris removal. Some analysis are currently in progress as the study will end in August. It compares the efficiency of in-orbit Active Removal of typical debris using electric propulsion The electric engine performances used in this analysis are demonstrated through a 2012/2013 PPS 5000 on-ground tests campaign. The traded missions are based on a launch in LEO, the possible vehicle architectures with capture means or contact less, the selection of deorbiting or reorbiting strategy. For contact less strategy, the ion-beam shepherd effect towards the debris problematic will be addressed. Vehicle architecture and performance of the overall system will be stated, showing the adequacy and the limits of each solution.

  14. Working Memory Training: Improving Intelligence--Changing Brain Activity

    Science.gov (United States)

    Jausovec, Norbert; Jausovec, Ksenija

    2012-01-01

    The main objectives of the study were: to investigate whether training on working memory (WM) could improve fluid intelligence, and to investigate the effects WM training had on neuroelectric (electroencephalography--EEG) and hemodynamic (near-infrared spectroscopy--NIRS) patterns of brain activity. In a parallel group experimental design,…

  15. Oxidative stress and superoxide dismutase activity in brain of rats ...

    African Journals Online (AJOL)

    The present study was envisaged to investigate the possible role of oxidative stress in permethrin neurotoxicity and to evaluate the protective effect of superoxide dismutase (SOD) activity in brain homogenates of Wistar rats. Oxidative stress measured as thiobarbituric acid reacting substances (TBARS) was found to ...

  16. Towards a fourth spatial dimension of brain activity.

    Science.gov (United States)

    Tozzi, Arturo; Peters, James F

    2016-06-01

    Current advances in neurosciences deal with the functional architecture of the central nervous system, paving the way for general theories that improve our understanding of brain activity. From topology, a strong concept comes into play in understanding brain functions, namely, the 4D space of a "hypersphere's torus", undetectable by observers living in a 3D world. The torus may be compared with a video game with biplanes in aerial combat: when a biplane flies off one edge of gaming display, it does not crash but rather it comes back from the opposite edge of the screen. Our thoughts exhibit similar behaviour, i.e. the unique ability to connect past, present and future events in a single, coherent picture as if we were allowed to watch the three screens of past-present-future "glued" together in a mental kaleidoscope. Here we hypothesize that brain functions are embedded in a imperceptible fourth spatial dimension and propose a method to empirically assess its presence. Neuroimaging fMRI series can be evaluated, looking for the topological hallmark of the presence of a fourth dimension. Indeed, there is a typical feature which reveal the existence of a functional hypersphere: the simultaneous activation of areas opposite each other on the 3D cortical surface. Our suggestion-substantiated by recent findings-that brain activity takes place on a closed, donut-like trajectory helps to solve long-standing mysteries concerning our psychological activities, such as mind-wandering, memory retrieval, consciousness and dreaming state.

  17. Oxidative stress and superoxide dismutase activity in brain of rats ...

    African Journals Online (AJOL)

    JTEkanem

    Oxidative stress and superoxide dismutase activity in brain of rats fed with diet containing permethrin. Olawale OTITOJU1, Ikechukwu N. E. ONWURAH2*, Grace T. O. OTITOJU3 and. Chidiebere E. UGWU4. 1Department of Biochemistry, Faculty of Basic Medical Sciences, University of Uyo, Uyo,. Nigeria. 2 Pollution Control ...

  18. Alcohol dependence and anxiety increase error-related brain activity.

    NARCIS (Netherlands)

    Schellekens, A.F.A.; Bruijn, E.R. de; Lankveld, C.A. van; Hulstijn, W.; Buitelaar, J.K.; Jong, C.A.J. de; Verkes, R.J.

    2010-01-01

    AIMS: Detection of errors is crucial for efficient goal-directed behaviour. The ability to monitor behaviour is found to be diminished in patients with substance dependence, as reflected in decreased error-related brain activity, i.e. error-related negativity (ERN). The ERN is also decreased in

  19. Alcohol dependence and anxiety increase error-related brain activity

    NARCIS (Netherlands)

    Schellekens, A.F.A.; Bruijn, E.R.A. de; Lankveld, C.A.A. van; Hulstijn, W.; Buitelaar, J.K.; Jong, C.A.J. de; Verkes, R.J.

    2010-01-01

    Aims Detection of errors is crucial for efficient goal-directed behaviour. The ability to monitor behaviour is found to be diminished in patients with substance dependence, as reflected in decreased error-related brain activity, i.e. error-related negativity (ERN). The ERN is also decreased in other

  20. Abnormal brain activation in excoriation (skin-picking) disorder

    DEFF Research Database (Denmark)

    Odlaug, Brian L.; Hampshire, Adam; Chamberlain, Samuel R

    2016-01-01

    planning task (Tower of London) during functional magnetic resonance imaging (fMRI). Activation during planning was compared between groups using region of interest and whole-brain permutation cluster approaches. Results: The SPD group exhibited significant functional underactivation in a cluster...

  1. Smart Moves: Powering up the Brain with Physical Activity

    Science.gov (United States)

    Conyers, Marcus; Wilson, Donna

    2015-01-01

    The Common Core State Standards emphasize higher-order thinking, problem solving, and the creation, retention, and application of knowledge. Achieving these standards creates greater cognitive demands on students. Recent research suggests that active play and regular exercise have a positive effect on brain regions associated with executive…

  2. Specific features of learning with nociceptive electrical reinforcement in rats of different genetic strains: role of brain neurotransmitter systems.

    Science.gov (United States)

    Kalyuzhnyi, A L; Litvinova, S V; Shulgovskii, V V; Panchenko, L F

    2005-01-01

    The interaction between neurotransmitter systems and opioid system in rats of different strains was studied during learning and emotional stress. The interaction between noradrenergic, serotoninergic, and opioid systems in the brain is the main neurochemical mechanism underlying learning reinforced by nociceptive electrical stimulation, which determine individual differences in the rate and type of learning.

  3. The integration of functional brain activity from adolescence to adulthood.

    Science.gov (United States)

    Kundu, Prantik; Benson, Brenda E; Rosen, Dana; Frangou, Sophia; Leibenluft, Ellen; Luh, Wen-Ming; Bandettini, Peter A; Pine, Daniel S; Ernst, Monique

    2018-02-27

    Age-related changes in human functional neuroanatomy are poorly understood. This is partly due to the limits to interpretation of standard fMRI. These limits relate to age-related variation in noise levels across subjects, and the frequent need for standard adult parcellations in developmental studies. Here we used an emerging MRI approach called multi-echo (ME)-fMRI to characterize functional brain changes with age. ME-fMRI acquires blood oxygenation level dependent (BOLD) signals while also quantifying T2* signal decay. This newly enables reliable analysis of BOLD components at the subject level. We hypothesized that BOLD components of the resting state are not stable with age, and would decrease in number from adolescence to adulthood. This runs counter to the current assumptions in neurodevelopmental analyses of brain connectivity that the number of components is a random effect. From resting state ME-fMRI of 51 healthy subjects of both sexes, between ages of 8.3 and 46.2 y, we found a highly significant (R=-0.55, p[dlt]0.001) exponential decrease in the number of BOLD components with age. The number of BOLD components were halved from adolescence to the fifth decade of life, stabilizing in middle adulthood. The regions driving this change were dorsolateral prefrontal cortices, parietal cortex, and cerebellum. The functional network of these regions centered on the cerebellum. We conclude that age-related decrease in BOLD component number concurs with the hypothesis of neurodevelopmental integration of functional brain activity. We show evidence that the cerebellum may play a key role in this process. SIGNIFICANCE STATEMENT Human brain development is ongoing to at least age 30. Functional MRI (fMRI) is key for studying the change in brain function with development. However, developmental fMRI studies have relied on reference maps of brain organization derived from adult data. This may limit sensitivity to major differences in younger brains. We created an f

  4. Participation in leisure activities during brain injury rehabilitation.

    Science.gov (United States)

    Fleming, Jennifer; Braithwaite, Helen; Gustafsson, Louise; Griffin, Janelle; Collier, Ann Maree; Fletcher, Stephanie

    2011-01-01

    To describe and compare pre- and post-injury leisure activities of individuals receiving brain injury rehabilitation and explore levels of leisure participation and satisfaction. Cross-sectional descriptive study incorporating a survey of current and past leisure activities. Questionnaires were completed by 40 individuals with an acquired brain injury receiving inpatient or outpatient rehabilitation. Shortened Version of the Nottingham Leisure Questionnaire and Changes in Leisure Questionnaire (developed for this study). Leisure participation declined following injury, particularly in social leisure activities. Pre-injury activities with high rates of discontinued or decreased participation were driving, going to pubs and parties, do-it-yourself activities and attending sports events. Inpatient participants generally attributed decreased participation to the hospital environment, whereas outpatient participants reported this predominantly as a result of disability. Post-injury levels of perceived leisure satisfaction were significantly lower for the inpatient group compared to pre-injury, but not for the outpatient group. Uptake of some new leisure activities was reported post-injury, however not at the rate to which participation declined. Leisure participation decreases during brain injury rehabilitation compared to pre-injury levels. Re-engagement in relevant, age-appropriate leisure activities needs to be addressed during rehabilitation to improve participation in this domain.

  5. In vivo bioimpedance measurement of healthy and ischaemic rat brain: implications for stroke imaging using electrical impedance tomography.

    Science.gov (United States)

    Dowrick, T; Blochet, C; Holder, D

    2015-06-01

    In order to facilitate the imaging of haemorrhagic and ischaemic stroke using frequency difference electrical impedance tomography (EIT), impedance measurements of normal and ischaemic brain, and clotted blood during haemorrhage, were gathered using a four-terminal technique in an in vivo animal model, a first for ischaemic measurements. Differences of 5-10% in impedance were seen between the frequency spectrums of healthy and ischaemic brain, over the frequency range 0-3 kHz, while the spectrum of blood was predominately uniform. The implications of imaging blood/ischaemia in the brain using electrical impedance tomography are discussed, supporting the notion that it will be possible to differentiate stroke from haemorrhage.

  6. [Mechanical and electrical uterine activity. Part II. Contractions parameters].

    Science.gov (United States)

    Zietek, Jerzy; Sikora, Jerzy; Horoba, Krzysztof; Matonia, Adam; Jezewski, Janusz; Magnucki, Jacek; Kobielska, Lucyna

    2008-11-01

    Frequency and strength of the uterine contractions monitoring enables to control the labour progress and also, although in a restricted way, to determine the beginning of labour, as long as it is not preterm. Mechanical approach provides only the low frequency signal, which describes the contractions more or less accurately, depending on whether an intrauterine pressure measurement is used in the former case or whether an external stress measurement is applied in the latter case. This signal does not comprise information on contractions characteristics and enables only to estimate their basic timing parameters. Description of the electrophysiological properties may be obtained only by means of the uterine electrical signals measurement. In the following paper, the classical interpretation of the uterine contraction activity which relies upon its mechanical and electrical activity was presented. Additionally, the frequency parameters provided exclusively by the electrical signal were proposed. The possibility of the electrohysterogram analysis may provide more complete information on uterine muscle functioning. Results of the research studies show that further development of electrohysterography will enable its wider application in pregnancy and labour diagnostics.

  7. Oral ambroxol increases brain glucocerebrosidase activity in a nonhuman primate

    OpenAIRE

    Migdalska-Richards, A.; Ko, W. K. D.; Li, Q.; Bezard, E.; Schapira, A H V

    2017-01-01

    Abstract Mutations in the glucocerebrosidase 1 (GBA1) gene are related to both Parkinson disease (PD) and Gaucher disease (GD). In both cases, the condition is associated with deficiency of glucocerebrosidase (GCase), the enzyme encoded by GBA1. Ambroxol is a small molecule chaperone that has been shown in mice to cross the blood?brain barrier, increase GCase activity and reduce alpha?synuclein protein levels. In this study, we analyze the effect of ambroxol treatment on GCase activity in hea...

  8. Variance and Autocorrelation of the Spontaneous Slow Brain Activity

    Science.gov (United States)

    Kaneoke, Yoshiki; Donishi, Tomohiro; Iwatani, Jun; Ukai, Satoshi; Shinosaki, Kazuhiro; Terada, Masaki

    2012-01-01

    Slow (autocorrelation coefficient (r1). These two maps had distinct spatial distributions and the values were significantly different among the subdivisions of the precuneus and posterior cingulate cortex that were identified in functional connectivity (FC) studies. The results reinforce the functional segregation of these subdivisions and indicate that the intrinsic properties of the slow brain activity have physiological relevance. Further, we propose a sample size (degree of freedom) correction when assessing the statistical significance of FC strength with r1 values, which enables a better understanding of the network changes related to various brain diseases. PMID:22666461

  9. Electrically active defects in solar grade multicrystalline silicon

    DEFF Research Database (Denmark)

    Dahl, Espen

    2013-01-01

    Shortage in high purity silicon feedstock, as a result of the formidable increased demand for solar cell devices during the last two decades, can be mitigated by the introduction of cheaper feedstock of solar grade (So-G) quality. Silicon produced through the metallurgical process route has shown......: defect centre characterisation with Deep Level Transient Spectroscopy (DLTS), determination of the electrical performance with Microwave Photoconductive Decay (µ-PCD), chemical analysis with Secondary Ion-Mass Spectrometry (SIMS) and different types of electron microscopy imaging (TEM, SEM, tabletop......-SEM) for structural analysis. Some additional techniques have been implemented in order to fill in missing information. In addition, a part of the study aimed at improving the electrical performance of the material, by removing metallic impurities from active phases, with different gettering techniques. It was found...

  10. Mitochondrial activity and brain functions during cortical depolarization

    Science.gov (United States)

    Mayevsky, Avraham; Sonn, Judith

    2008-12-01

    Cortical depolarization (CD) of the cerebral cortex could be developed under various pathophysiological conditions. In animal models, CD was recorded under partial or complete ischemia as well as when cortical spreading depression (SD) was induced externally or by internal stimulus. The development of CD in patients and the changes in various metabolic parameters, during CD, was rarely reported. Brain metabolic, hemodynamic, ionic and electrical responses to the CD event are dependent upon the O2 balance in the tissue. When the O2 balance is negative (i.e. ischemia), the CD process will be developed due to mitochondrial dysfunction, lack of energy and the inhibition of Na+-K+-ATPase. In contradiction, when oxygen is available (i.e. normoxia) the development of CD after induction of SD will accelerate mitochondrial respiration for retaining ionic homeostasis and normal brain functions. We used the multiparametric monitoring approach that enable real time monitoring of mitochondrial NADH redox state, microcirculatory blood flow and oxygenation, extracellular K+, Ca2+, H+ levels, DC steady potential and electrocorticogram (ECoG). This monitoring approach, provide a unique tool that has a significant value in analyzing the pathophysiology of the brain when SD developed under normoxia, ischemia, or hypoxia. We applied the same monitoring approach to patients suffered from severe head injury or exposed to neurosurgical procedures.

  11. Bio-optical sensor for brain activity measurement based on whispering gallery modes

    Science.gov (United States)

    Ali, Amir R.; Massoud, Yasmin M.

    2017-05-01

    In this paper, a high-resolution bio-optical sensor is developed for brain activity measurement. The aim is to develop an optical sensor with enough sensitivity to detect small electric field perturbations caused by neuronal action potential. The sensing element is a polymeric dielectric micro-resonator fabricated in a spherical shape with a few hundred microns in diameter. They are made of optical quality polymers that are soft which make them mechanically compatible with tissue. The sensors are attached to or embedded in optical fibers which serve as input/output conduits for the sensors. Hundreds or even thousands of spheres can be attached to a single fiber to detect and transmit signals at different locations. The high quality factor for the optical resonator makes it significantly used in such bio-medical applications. The sensing phenomenon is based on whispering gallery modes (WGM) shifts of the optical sensor. To mimic the brain signals, the spherical resonator is immersed in a homogeneous electrical field that is created by applying potential difference across two metallic plates. One of the plates has a variable voltage while the volt on the other plate kept fixed. Any small perturbations of the potential difference (voltage) lead to change in the electric field intensity. In turn the sensor morphology will be affected due to the change in the electrostriction force acting on it causing change in its WGM. By tracking these WGM shift on the transmission spectrum, the induced potential difference (voltage change) could be measured. Results of a mathematical model simulation agree well with the preliminary experiments. Also, the results show that the brain activity could be measured using this principle.

  12. Resting Brain Activity Related to Dispositional Mindfulness: a PET Study.

    Science.gov (United States)

    Gartenschläger, Martin; Schreckenberger, Mathias; Buchholz, Hans-Georg; Reiner, Iris; Beutel, Manfred E; Adler, Julia; Michal, Matthias

    2017-01-01

    Mindfulness denotes a state of consciousness characterized by receptive attention to and awareness of present events and experiences. As a personality trait, it constitutes the ability to become aware of mental activities such as sensations, images, feelings, and thoughts, and to disengage from judgment, conditioned emotions, and their cognitive processing or automatic inhibition. Default brain activity reflects the stream of consciousness and sense of self at rest. Analysis of brain activity at rest in persons with mindfulness propensity may help to elucidate the neurophysiological basis of this important mental trait. The sample consisted of 32 persons-23 with mental disorders and 9 healthy controls. Dispositional mindfulness (DM) was operationalized by Mindful Attention Awareness Scale (MAAS). Brain activity at rest with eyes closed was assessed by fluorodeoxyglucose positron emission tomography (F-18-FDG PET). After adjustment for depression, anxiety, age and years of education, resting glucose metabolism in superior parietal lobule and left precuneus/Brodmann area (BA) 7 was positively associated with DM. Activity of the left inferior frontal orbital gyrus (BA 47) and bilateral anterior thalamus were inversely associated with DM. DM appears to be associated with increased metabolic activity in some core area of the default mode network (DMN) and areas connected to the DMN, such as BA 7, hosting sense of self functions. Hypometabolism on the other hand was found in some nodes connected to the DMN, such as left inferior frontal orbital gyrus and bilateral thalamus, commonly related to functions of memory retrieval, decision making, or outward attention.

  13. Trying to trust: Brain activity during interpersonal social attitude change.

    Science.gov (United States)

    Filkowski, Megan M; Anderson, Ian W; Haas, Brian W

    2016-04-01

    Interpersonal trust and distrust are important components of human social interaction. Although several studies have shown that brain function is associated with either trusting or distrusting others, very little is known regarding brain function during the control of social attitudes, including trust and distrust. This study was designed to investigate the neural mechanisms involved when people attempt to control their attitudes of trust or distrust toward another person. We used a novel control-of-attitudes fMRI task, which involved explicit instructions to control attitudes of interpersonal trust and distrust. Control of trust or distrust was operationally defined as changes in trustworthiness evaluations of neutral faces before and after the control-of-attitudes fMRI task. Overall, participants (n = 60) evaluated faces paired with the distrust instruction as being less trustworthy than faces paired with the trust instruction following the control-of-distrust task. Within the brain, both the control-of-trust and control-of-distrust conditions were associated with increased temporoparietal junction, precuneus (PrC), inferior frontal gyrus (IFG), and medial prefrontal cortex activity. Individual differences in the control of trust were associated with PrC activity, and individual differences in the control of distrust were associated with IFG activity. Together, these findings identify a brain network involved in the explicit control of distrust and trust and indicate that the PrC and IFG may serve to consolidate interpersonal social attitudes.

  14. Brain activities associated with gaming urge of online gaming addiction.

    Science.gov (United States)

    Ko, Chih-Hung; Liu, Gin-Chung; Hsiao, Sigmund; Yen, Ju-Yu; Yang, Ming-Jen; Lin, Wei-Chen; Yen, Cheng-Fang; Chen, Cheng-Sheng

    2009-04-01

    The aim of this study was to identify the neural substrates of online gaming addiction through evaluation of the brain areas associated with the cue-induced gaming urge. Ten participants with online gaming addiction and 10 control subjects without online gaming addiction were tested. They were presented with gaming pictures and the paired mosaic pictures while undergoing functional magnetic resonance imaging (fMRI) scanning. The contrast in blood-oxygen-level dependent (BOLD) signals when viewing gaming pictures and when viewing mosaic pictures was calculated with the SPM2 software to evaluate the brain activations. Right orbitofrontal cortex, right nucleus accumbens, bilateral anterior cingulate and medial frontal cortex, right dorsolateral prefrontal cortex, and right caudate nucleus were activated in the addicted group in contrast to the control group. The activation of the region-of-interest (ROI) defined by the above brain areas was positively correlated with self-reported gaming urge and recalling of gaming experience provoked by the WOW pictures. The results demonstrate that the neural substrate of cue-induced gaming urge/craving in online gaming addiction is similar to that of the cue-induced craving in substance dependence. The above-mentioned brain regions have been reported to contribute to the craving in substance dependence, and here we show that the same areas were involved in online gaming urge/craving. Thus, the results suggest that the gaming urge/craving in online gaming addiction and craving in substance dependence might share the same neurobiological mechanism.

  15. Water diffusion closely reveals neural activity status in rat brain loci affected by anesthesia.

    Directory of Open Access Journals (Sweden)

    Yoshifumi Abe

    2017-04-01

    Full Text Available Diffusion functional MRI (DfMRI reveals neuronal activation even when neurovascular coupling is abolished, contrary to blood oxygenation level-dependent (BOLD functional MRI (fMRI. Here, we show that the water apparent diffusion coefficient (ADC derived from DfMRI increased in specific rat brain regions under anesthetic conditions, reflecting the decreased neuronal activity observed with local field potentials (LFPs, especially in regions involved in wakefulness. In contrast, BOLD signals showed nonspecific changes, reflecting systemic effects of the anesthesia on overall brain hemodynamics status. Electrical stimulation of the central medial thalamus nucleus (CM exhibiting this anesthesia-induced ADC increase led the animals to transiently wake up. Infusion in the CM of furosemide, a specific neuronal swelling blocker, led the ADC to increase further locally, although LFP activity remained unchanged, and increased the current threshold awakening the animals under CM electrical stimulation. Oppositely, induction of cell swelling in the CM through infusion of a hypotonic solution (-80 milliosmole [mOsm] artificial cerebrospinal fluid [aCSF] led to a local ADC decrease and a lower current threshold to wake up the animals. Strikingly, the local ADC changes produced by blocking or enhancing cell swelling in the CM were also mirrored remotely in areas functionally connected to the CM, such as the cingulate and somatosensory cortex. Together, those results strongly suggest that neuronal swelling is a significant mechanism underlying DfMRI.

  16. Active Lessons for Active Brains: Teaching Boys and Other Experiential Learners, Grades 3-10

    Science.gov (United States)

    James, Abigail Norfleet; Allison, Sandra Boyd; McKenzie, Caitlin Zimmerman

    2011-01-01

    If you're tired of repeating yourself to students who aren't listening, try a little less talk and a lot more action. The authors follow the best-selling "Teaching the Male Brain and Teaching the Female Brain" with this ready-to-use collection of mathematics, language arts, science, and classroom management strategies. Designed for active,…

  17. Brain Activity at the Embryonic Stages of Development

    Directory of Open Access Journals (Sweden)

    D.R. Akhmetshina

    2015-06-01

    Full Text Available The main function of our brain is to run internal models of the external world. These models enable us to analyze complex sensory inputs from the outside and our bodies, as well as to generate a system of commands underlying our behavior. This is implemented by a complex network, which is built out of billions of interconnected neurons. The network is formed during the ontogeny with the most intense phase of synaptogenesis starting during second half of gestation in the utero. So, the neonate is born with a remarkably developed frame of the central nervous system capable of receiving, processing, and memorizing information from the external world. This review discusses how the brain operates during the fetal stages of development and how the early activities expressed in the fetal brain contribute to the prenatal assembly of the nervous system.

  18. Hyperbaric Oxygen Environment Can Enhance Brain Activity and Multitasking Performance.

    Science.gov (United States)

    Vadas, Dor; Kalichman, Leonid; Hadanny, Amir; Efrati, Shai

    2017-01-01

    Background: The Brain uses 20% of the total oxygen supply consumed by the entire body. Even though, multitasking), the oxygen supply is shifted from one brain region to another, via blood perfusion modulation. The aim of the present study was to evaluate whether a hyperbaric oxygen (HBO) environment, with increased oxygen supply to the brain, will enhance the performance of complex and/or multiple activities. Methods: A prospective, double-blind randomized control, crossover trial including 22 healthy volunteers. Participants were asked to perform a cognitive task, a motor task and a simultaneous cognitive-motor task (multitasking). Participants were randomized to perform the tasks in two environments: (a) normobaric air (1 ATA 21% oxygen) (b) HBO (2 ATA 100% oxygen). Two weeks later participants were crossed to the alternative environment. Blinding of the normobaric environment was achieved in the same chamber with masks on while hyperbaric sensation was simulated by increasing pressure in the first minute and gradually decreasing to normobaric environment prior to tasks performance. Results: Compared to the performance at normobaric conditions, both cognitive and motor single tasks scores were significantly enhanced by HBO environment (p Multitasking performance was also significantly enhanced in HBO environment (p = 0.006 for the cognitive part and p = 0.02 for the motor part). Conclusions: The improvement in performance of both single and multi-tasking while in an HBO environment supports the hypothesis which according to, oxygen is indeed a rate limiting factor for brain activity. Hyperbaric oxygenation can serve as an environment for brain performance. Further studies are needed to evaluate the optimal oxygen levels for maximal brain performance.

  19. Rehabilitation of hand in subacute tetraplegic patients based on brain computer interface and functional electrical stimulation: a randomised pilot study

    Science.gov (United States)

    Osuagwu, Bethel C. A.; Wallace, Leslie; Fraser, Mathew; Vuckovic, Aleksandra

    2016-12-01

    Objective. To compare neurological and functional outcomes between two groups of hospitalised patients with subacute tetraplegia. Approach. Seven patients received 20 sessions of brain computer interface (BCI) controlled functional electrical stimulation (FES) while five patients received the same number of sessions of passive FES for both hands. The neurological assessment measures were event related desynchronization (ERD) during movement attempt, Somatosensory evoked potential (SSEP) of the ulnar and median nerve; assessment of hand function involved the range of motion (ROM) of wrist and manual muscle test. Main results. Patients in both groups initially had intense ERD during movement attempt that was not restricted to the sensory-motor cortex. Following the treatment, ERD cortical activity restored towards the activity in able-bodied people in BCI-FES group only, remaining wide-spread in FES group. Likewise, SSEP returned in 3 patients in BCI-FES group, having no changes in FES group. The ROM of the wrist improved in both groups. Muscle strength significantly improved for both hands in BCI-FES group. For FES group, a significant improvement was noticed for right hand flexor muscles only. Significance. Combined BCI-FES therapy results in better neurological recovery and better improvement of muscle strength than FES alone. For spinal cord injured patients, BCI-FES should be considered as a therapeutic tool rather than solely a long-term assistive device for the restoration of a lost function.

  20. Interindividual synchronization of brain activity during live verbal communication.

    Science.gov (United States)

    Spiegelhalder, Kai; Ohlendorf, Sabine; Regen, Wolfram; Feige, Bernd; Tebartz van Elst, Ludger; Weiller, Cornelius; Hennig, Jürgen; Berger, Mathias; Tüscher, Oliver

    2014-01-01

    Verbal social interaction plays an important role both in the etiology and treatment of psychiatric disorders. However, the neural basis of social interaction has primarily been studied in the individual brain, neglecting the inter-individual perspective. Here, we show inter-individual neuronal coupling of brain activity during live verbal interaction, by investigating 11 pairs of good female friends who were instructed to speak about autobiographical life events during simultaneous fMRI acquisition. The analysis revealed that the time course of neural activity in areas associated with speech production was coupled with the time course of neural activity in the interlocutor's auditory cortex. This shows the feasibility of the new methodology, which may help elucidate basic reciprocal mechanisms of social interaction and the underpinnings of disordered communication. In particular, it may serve to study the process of psychotherapy on a neuronal level. Copyright © 2013 Elsevier B.V. All rights reserved.

  1. Oral ambroxol increases brain glucocerebrosidase activity in a nonhuman primate

    Science.gov (United States)

    Migdalska‐Richards, Anna; Ko, Wai Kin D.; Li, Qin; Bezard, Erwan

    2017-01-01

    Abstract Mutations in the glucocerebrosidase 1 (GBA1) gene are related to both Parkinson disease (PD) and Gaucher disease (GD). In both cases, the condition is associated with deficiency of glucocerebrosidase (GCase), the enzyme encoded by GBA1. Ambroxol is a small molecule chaperone that has been shown in mice to cross the blood‐brain barrier, increase GCase activity and reduce alpha‐synuclein protein levels. In this study, we analyze the effect of ambroxol treatment on GCase activity in healthy nonhuman primates. We show that daily administration of ambroxol results in increased brain GCase activity. Our work further indicates that ambroxol should be investigated as a novel therapy for both PD and neuronopathic GD in humans. PMID:28295625

  2. AC Electric Field Activated Shape Memory Polymer Composite

    Science.gov (United States)

    Kang, Jin Ho; Siochi, Emilie J.; Penner, Ronald K.; Turner, Travis L.

    2011-01-01

    Shape memory materials have drawn interest for applications like intelligent medical devices, deployable space structures and morphing structures. Compared to other shape memory materials like shape memory alloys (SMAs) or shape memory ceramics (SMCs), shape memory polymers (SMPs) have high elastic deformation that is amenable to tailored of mechanical properties, have lower density, and are easily processed. However, SMPs have low recovery stress and long response times. A new shape memory thermosetting polymer nanocomposite (LaRC-SMPC) was synthesized with conductive fillers to enhance its thermo-mechanical characteristics. A new composition of shape memory thermosetting polymer nanocomposite (LaRC-SMPC) was synthesized with conductive functionalized graphene sheets (FGS) to enhance its thermo-mechanical characteristics. The elastic modulus of LaRC-SMPC is approximately 2.7 GPa at room temperature and 4.3 MPa above its glass transition temperature. Conductive FGSs-doped LaRC-SMPC exhibited higher conductivity compared to pristine LaRC SMP. Applying an electric field at between 0.1 Hz and 1 kHz induced faster heating to activate the LaRC-SMPC s shape memory effect relative to applying DC electric field or AC electric field at frequencies exceeding1 kHz.

  3. Xanthine oxidase activity regulates human embryonic brain cells growth

    Directory of Open Access Journals (Sweden)

    Kevorkian G. A.

    2011-10-01

    Full Text Available Aim. Involvement of Xanthine Oxidase (XO; EC1.1.3.22 in cellular proliferation and differentiation has been suggested by the numerous investigations. We have proposed that XO might have undoubtedly important role during the development, maturation as well as the death of human embryos brain cells. Methods. Human abortion material was utilized for the cultivation of brain cells (E90. XO activity was measured by the formation of uric acid in tissue. Cell death was detected by the utility of Trypan Blue dye. Results. Allopurinol suppressed the XO activity in the brain tissue (0.12 ± 0.02; 0.20 ± 0.03 resp., p < 0.05. On day 12th the number of cells in the culture treated with the Allopurinol at the early stage of development was higher in comparison with the Control (2350.1 ± 199.0 vs 2123 ± 96 and higher in comparison with the late period of treatment (1479.6 ± 103.8, p < < 0.05. In all groups, the number of the dead cells was less than in Control, indicating the protective nature of Allopurinol as an inhibitor of XO. Conclusions. Allopurinol initiates cells proliferation in case of the early treatment of the human brain derived cell culture whereas at the late stages it has an opposite effect.

  4. Association between physical activity and brain health in older adults.

    Science.gov (United States)

    Benedict, Christian; Brooks, Samantha J; Kullberg, Joel; Nordenskjöld, Richard; Burgos, Jonathan; Le Grevès, Madeleine; Kilander, Lena; Larsson, Elna-Marie; Johansson, Lars; Ahlström, Håkan; Lind, Lars; Schiöth, Helgi B

    2013-01-01

    In the present cross-sectional study, we examined physical activity (PA) and its possible association with cognitive skills and brain structure in 331 cognitively healthy elderly. Based on the number of self-reported light and hard activities for at least 30 minutes per week, participants were assigned to 4 groups representing different levels of PA. The cognitive skills were assessed by the Mini Mental State Examination score, a verbal fluency task, and the Trail-making test as a measure of visuospatial orientation ability. Participants also underwent a magnetic resonance imaging of the brain. Multiple regression analysis revealed that greater PA was associated with a shorter time to complete the Trail-making test, and higher levels of verbal fluency. Further, the level of self-reported PA was positively correlated with brain volume, white matter, as well as a parietal lobe gray matter volume, situated bilaterally at the precuneus. These present cross-sectional results indicate that PA is a lifestyle factor that is linked to brain structure and function in late life. Copyright © 2013 Elsevier Inc. All rights reserved.

  5. Contributions of Glycogen to Astrocytic Energetics during Brain Activation

    Science.gov (United States)

    Dienel, Gerald A.; Cruz, Nancy F.

    2014-01-01

    Glycogen is the major store of glucose in brain and is mainly in astrocytes. Brain glycogen levels in unstimulated, carefully-handled rats are 10-12 mol/g, and assuming that astrocytes account for half the brain mass, astrocytic glycogen content is twice as high. Glycogen turnover is slow under basal conditions, but it is mobilized during activation. There is no net increase in incorporation of label from glucose during activation, whereas label release from pre-labeled glycogen exceeds net glycogen consumption, which increases during stronger stimuli. Because glycogen level is restored by non-oxidative metabolism, astrocytes can influence the global ratio of oxygen to glucose utilization. Compensatory increases in utilization of blood glucose during inhibition of glycogen phosphorylase are large and approximate glycogenolysis rates during sensory stimulation. In contrast, glycogenolysis rates during hypoglycemia are low due to continued glucose delivery and oxidation of endogenous substrates; rates that preserve neuronal function in the absence of glucose are also low, probably due to metabolite oxidation. Modeling studies predict that glycogenolysis maintains a high level of glucose-6-phosphate in astrocytes to maintain feedback inhibition of hexokinase, thereby diverting glucose for use by neurons. The fate of glycogen carbon in vivo is not known, but lactate efflux from brain best accounts for the major metabolic characteristics during activation of living brain. Substantial shuttling coupled with oxidation of glycogen-derived lactate is inconsistent with available evidence. Glycogen has important roles in astrocytic energetics, including glucose sparing, control of extracellular K+ level, oxidative stress management, and memory consolidation; it is a multi-functional compound. PMID:24515302

  6. Alteration of spontaneous brain activity in COPD patients

    Directory of Open Access Journals (Sweden)

    Zhang J

    2016-07-01

    Full Text Available Jiaxing Zhang,1 Ji Chen,1 Qian Yu,1 Cunxiu Fan,1 Ran Zhang,1 Jianzhong Lin,2 Tianhe Yang,2 Ming Fan3 1Department of Physiology, Medical College of Xiamen University, Xiangan, 2Magnetic Resonance Center, Department of Radiology, Zhongshan Hospital Xiamen University, Xiamen, Fujian, 3Department of Cognitive Sciences, Institute of Basic Medical Sciences, Beijing, People’s Republic of China Background and objective: Airflow limitation in chronic obstructive pulmonary disease (COPD results in a decrease in oxygen transport to the brain. The aim of the present study was to explore the alteration of spontaneous brain activity induced by hypoxia in patients with COPD. Patients and methods: Twenty-five stable patients with COPD and 25 matching healthy volunteers were investigated. Amplitude of low-frequency fluctuation (ALFF of blood oxygenation level-dependent signal at resting state in the brain was analyzed using functional magnetic resonance imaging. Results: Whole-brain analysis using functional magnetic resonance imaging revealed significant decreases in ALFF in the bilateral posterior cingulate gyri and right lingual gyrus and an increase in ALFF in the left postcentral gyrus of patients with COPD. After controlling for SaO2, patients with COPD only showed an increase in ALFF in the left postcentral gyrus. Region of interest analysis showed a decrease in ALFF in the left precentral gyrus and an increase in ALFF in the left caudate nucleus of patients with COPD. In all subjects, ALFF in the bilateral posterior cingulate gyri and right lingual gyrus showed positive correlations with visual reproduction. Conclusion: We demonstrated abnormal spontaneous brain activity of patients with COPD, which may have a pathophysiologic meaning. Keywords: chronic obstructive pulmonary disease, hypoxia, low-frequency fluctuation, neuronal activity, resting-state fMRI

  7. An electric field induced in the retina and brain at threshold magnetic flux density causing magnetophosphenes

    Energy Technology Data Exchange (ETDEWEB)

    Hirata, Akimasa; Takano, Yukinori; Fujiwara, Osamu [Nagoya Institute of Technology, Department of Computer Science and Engineering (Japan); Dovan, Thanh [SP AusNet, Division of Network Strategy and Development (Australia); Kavet, Robert, E-mail: ahirata@nitech.ac.jp [Electric Power Research Institute, Palo Alto, CA (United States)

    2011-07-07

    For magnetic field exposures at extremely low frequencies, the electrostimulatory response with the lowest threshold is the magnetophosphene, a response that corresponds to an adult exposed to a 20 Hz magnetic field of nominally 8.14 mT. In the IEEE standard C95.6 (2002), the corresponding in situ field in the retinal locus of an adult-sized ellipsoidal was calculated to be 53 mV m{sup -1}. However, the associated dose in the retina and brain at a high level of resolution in anatomically correct human models is incompletely characterized. Furthermore, the dose maxima in tissue computed with voxel human models are prone to staircasing errors, particularly for the low-frequency dosimetry. In the analyses presented in this paper, analytical and quasi-static finite-difference time-domain (FDTD) solutions were first compared for a three-layer sphere exposed to a uniform 50 Hz magnetic field. Staircasing errors in the FDTD results were observed at the tissue interface, and were greatest at the skin-air boundary. The 99th percentile value was within 3% of the analytic maximum, depending on model resolution, and thus may be considered a close approximation of the analytic maximum. For the adult anatomical model, TARO, exposed to a uniform magnetic field, the differences in the 99th percentile value of in situ electric fields for 2 mm and 1 mm voxel models were at most several per cent. For various human models exposed at the magnetophosphene threshold at three orthogonal field orientations, the in situ electric field in the brain was between 10% and 70% greater than the analytical IEEE threshold of 53 mV m{sup -1}, and in the retina was lower by roughly 50% for two horizontal orientations (anterior-posterior and lateral), and greater by about 15% for a vertically oriented field. Considering a reduction factor or safety factors of several folds applied to electrostimulatory thresholds, the 99th percentile dose to a tissue calculated with voxel human models may be used as an

  8. A Study on the Effect of Electrical Stimulation as a User Stimuli for Motor Imagery Classification in Brain-Machine Interface.

    Science.gov (United States)

    Bhattacharyya, Saugat; Clerc, Maureen; Hayashibe, Mitsuhiro

    2016-06-13

    Functional Electrical Stimulation (FES) provides a neuroprosthetic interface to non-recovered muscle groups by stimulating the affected region of the human body. FES in combination with Brain-machine interfacing (BMI) has a wide scope in rehabilitation because this system directly links the cerebral motor intention of the users with its corresponding peripheral muscle activations. In this paper, we examine the effect of FES on the electroencephalography (EEG) during motor imagery (left- and right-hand movement) training of the users. Results suggest a significant improvement in the classification accuracy when the subject was induced with FES stimuli as compared to the standard visual one.

  9. Worry tendencies predict brain activation during aversive imagery.

    Science.gov (United States)

    Schienle, Anne; Schäfer, Axel; Pignanelli, Roman; Vaitl, Dieter

    2009-09-25

    Because of its abstract nature, worrying might function as an avoidance response in order to cognitively disengage from fearful imagery. The present functional magnetic resonance imaging study investigated neural correlates of aversive imagery and their association with worry tendencies, as measured by the Penn State Worry Questionnaire (PSWQ). Nineteen healthy women first viewed, and subsequently imagined pictures from two categories, 'threat' and 'happiness'. Worry tendencies were negatively correlated with brain activation in the anterior cingulate cortex, the prefrontal cortex (dorsolateral, dorsomedial, ventrolateral), the parietal cortex and the insula. These negative correlations between PSWQ scores and localized brain activation were specific for aversive imagery. Moreover, activation in the above mentioned regions was positively associated with the experienced vividness of both pleasant and unpleasant mental pictures. As the identified brain regions are involved in emotion regulation, vivid imagery and memory retrieval, a lowered activity in high PSWQ scorers might be associated with cognitive disengagement from aversive imagery as well as insufficient refresh rates of mental pictures. Our preliminary findings encourage future imagery studies on generalized anxiety disorder patients, as one of the main symptoms of this disorder is excessive worrying.

  10. Optical and electrical recording of neural activity evoked by graded contrast visual stimulus

    Directory of Open Access Journals (Sweden)

    Bulf Luca

    2007-07-01

    Full Text Available Abstract Background Brain activity has been investigated by several methods with different principles, notably optical ones. Each method may offer information on distinct physiological or pathological aspects of brain function. The ideal instrument to measure brain activity should include complementary techniques and integrate the resultant information. As a "low cost" approach towards this objective, we combined the well-grounded electroencephalography technique with the newer near infrared spectroscopy methods to investigate human visual function. Methods The article describes an embedded instrumentation combining a continuous-wave near-infrared spectroscopy system and an electroencephalography system to simultaneously monitor functional hemodynamics and electrical activity. Near infrared spectroscopy (NIRS signal depends on the light absorption spectra of haemoglobin and measures the blood volume and blood oxygenation regulation supporting the neural activity. The NIRS and visual evoked potential (VEP are concurrently acquired during steady state visual stimulation, at 8 Hz, with a b/w "windmill" pattern, in nine human subjects. The pattern contrast is varied (1%, 10%, 100% according to a stimulation protocol. Results In this study, we present the measuring system; the results consist in concurrent recordings of hemodynamic changes and evoked potential responses emerging from different contrast levels of a patterned stimulus. The concentration of [HbO2] increases and [HHb] decreases after the onset of the stimulus. Their variation shows a clear relationship with the contrast value: large contrast produce huge difference in concentration, while low contrast provokes small concentration difference. This behaviour is similar to the already known relationship between VEP response amplitude and contrast. Conclusion The simultaneous recording and analysis of NIRS and VEP signals in humans during visual stimulation with a b/w pattern at variable

  11. [Synchronization and propagation of electrical potentials in neural networks of the brain cortex].

    Science.gov (United States)

    Marchenko, V G; Zaĭchenko, M I

    2014-01-01

    On the basis of the published data the scheme is proposed which explains the spread and synhronization of oscillatory activity in cortex. The main property of the neocortex is the existence of vertically oriented functional columns. Within and between the neuronal columns exist a feedforward and feedback morphological and functional connections. At the certain conditions inside the single module temporal windows are created using inhibitory process, and a synchronized activity can be generated of variable frequency (oscillations). The activity in the columns is enhanced by the synchronous involvement of great amount of neurons which is expressed in the form of local field potentials of high amplitude. Further the information about arisen in a single generator activity is transmitted through direct links to the nearby generator or to the group of such generators. In the nearby generator the activity increases and is transferred to the next generator. At the same time the signal is transmitted through feedback to the primary generator, and the activity is terminated until the next cycle will be initiated and so on along the cortex. The most important notion is that in the transfer of activity from one generator to another is involved a small number of elements. The major part of recorded oscillations of different frequency or epileptiform discharges, is not transmitted via the brain, but is generated in each module according to the characteristics transferred to it. The generation of epileptiform spikes occurs in cases when balance of inhibition determined by GABA A and GABA B receptors is disturbed.

  12. Contribution of regional brain melanocortin receptor subtypes to elevated activity energy expenditure in lean, active rats

    OpenAIRE

    Shukla,Charu; Koch, Lauren G.; Britton, Steven L.; Cai, Minying; Hruby, Victor J.; Bednarek, Maria; Novak, Colleen M.

    2015-01-01

    Physical activity and non-exercise activity thermogenesis (NEAT) are crucial factors accounting for individual differences in body weight, interacting with genetic predisposition. In the brain, a number of neuroendocrine intermediates regulate food intake and energy expenditure (EE); this includes the brain melanocortin (MC) system, consisting of melanocortin peptides as well as their receptors (MCR). MC3R and MC4R have emerged as critical modulators of EE and food intake. To determine how va...

  13. Social anxiety disorder: radio electric asymmetric conveyor brain stimulation versus sertraline

    Science.gov (United States)

    Fontani, Vania; Mannu, Piero; Castagna, Alessandro; Rinaldi, Salvatore

    2011-01-01

    Purpose Social anxiety disorder (SAD) is a disabling condition that affects almost 5% of the general population. Many types of drugs have shown their efficacy in the treatment of SAD. There are also some data regarding psychotherapies, but no data are available today about the efficacy of brain stimulation techniques. The aim of the study is to compare the efficacy of noninvasive brain stimulation neuro psycho physical optimization (NPPO) protocol performed by radio electric asymmetric conveyor (REAC) with that of sertraline in adults with SAD. Patients and methods Twenty SAD patients on sertraline were compared with 23 SAD patients who refused any drug treatment and who chose to be treated with NPPO-REAC brain stimulation. This was a 6-month, open-label, naturalistic study. Patients on sertraline received flexible doses, whereas NPPO-REAC patients received two 18-session cycles of treatment. Clinical Global Improvement scale items “much improved” or “very much improved” and Liebowitz Social Anxiety Scale total score variation on fear and avoidance components were used to detect the results. The statistical analysis was performed with t-test. All measures <0.05 have been considered statistically significant. Results Ten of 23 subjects on NPPO-REAC and six of the 20 taking sertraline were much improved or very much improved 1 month after the first NPPO-REAC cycle (t1). Sixteen of the subjects on NPPO-REAC and ten of the subjects taking sertraline were much improved or very much improved 1 month after the second NPPO-REAC cycle (t2). In respect of the Liebowitz Social Anxiety Scale, at t1 NPPO-REAC resulted in statistically more efficacy for sertraline on both fear and avoidance total scores. At t2, NPPO-REAC resulted in statistically more efficacy for sertraline on fear but not on avoidance. Conclusion NPPO-REAC is an effective treatment for SAD, allowing substantial and clinically meaningful reductions in symptoms and disability in comparison with

  14. Brain activity and fatigue during prolonged exercise in the heat

    DEFF Research Database (Denmark)

    Hyldig, Tino Hoffmann

    2001-01-01

    .8-0.1 (SE) l min-1] cycling at 60% VO2max in a hot (H, 42°C) and a cool (C, 19°C) environment. Fast Fourier transformation of the EEG was used to obtain power spectrum areas in the ! (8-13 Hz) and # (13-30 Hz) frequencies. The ratio !/# was calculated as an index of arousal level; an elevated !/# index......We hypothesized that fatigue due to hyperthermia during prolonged exercise in the heat is in part related to alterations in frontal cortical brain activity. The electroencephalographic activity (EEG) of the frontal cortex of the brain was measured in seven cyclists [maximal O2 uptake (VO2max) 4...... min of exercise; PIncreases in the !/# index were strongly correlated to increases in Toes (r2=0.98; P=0.0001)....

  15. Time delay between cardiac and brain activity during sleep transitions

    Science.gov (United States)

    Long, Xi; Arends, Johan B.; Aarts, Ronald M.; Haakma, Reinder; Fonseca, Pedro; Rolink, Jérôme

    2015-04-01

    Human sleep consists of wake, rapid-eye-movement (REM) sleep, and non-REM (NREM) sleep that includes light and deep sleep stages. This work investigated the time delay between changes of cardiac and brain activity for sleep transitions. Here, the brain activity was quantified by electroencephalographic (EEG) mean frequency and the cardiac parameters included heart rate, standard deviation of heartbeat intervals, and their low- and high-frequency spectral powers. Using a cross-correlation analysis, we found that the cardiac variations during wake-sleep and NREM sleep transitions preceded the EEG changes by 1-3 min but this was not the case for REM sleep transitions. These important findings can be further used to predict the onset and ending of some sleep stages in an early manner.

  16. In pursuit of delay-related brain activity for anticipatory eye movements

    National Research Council Canada - National Science Library

    Burke, Melanie R; Barnes, Graham R

    2013-01-01

    ...) presentation of a moving stimulus. Using this design we could examine brain activity during a delay period using fMRI and have subsequently found a number of brain areas that reveal sustained activity during predictive pursuit...

  17. Human brain activity with near-infrared spectroscopy

    Science.gov (United States)

    Luo, Qingming; Chance, Britton

    1999-09-01

    Human brain activity was studied with a real time functional Near-InfraRed Imager (fNIRI). The imager has 16 measurement channels and covers 4 cm by 9 cm detection area. Brain activities in occipital, motor and prefrontal area were studied with the fNIRI. In prefrontal stimulation, language cognition, analogies, forming memory for new associations, emotional thinking, and mental arithmetic were carried out. Experimental results measured with fNIRI are demonstrated in this paper. It was shown that fNIRI technique is able to reveal the occipital activity during visual stimulation, and co-register well with results of fMRI in the motor cortex activity during finger tapping. In the studies of the effects of left prefrontal lobe on forming memory for new associations, it is shown that left prefrontal lobe activated more under deep conditions than that under shallow encoding, especially the dorsal part. In the studies of emotional thinking, it was shown that the responses were different between positive- negative emotional thinking and negative-positive emotional thinking. In mental arithmetic studies, higher activation was found in the first task than in the second, regardless of the difficulty, and higher activation was measured in subtraction of 17 than in subtraction of 3.

  18. MRI Brain Activation During Instruction of Dyslexic Children

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2003-08-01

    Full Text Available Ten children with dyslexia and 11 normal readers performed tasks of phoneme mapping (assigning sounds to letters and morpheme mapping (relating suffixed words to their roots during fMRI scanning, before and after 28 hours of comprehensive reading instruction, in a study of the effects of reading instruction on brain activation in children with dyslexia at University of Washington, Seattle, WA.

  19. Development of modularity in the neural activity of children's brains

    OpenAIRE

    Chen, Man; Deem, Michael W.

    2015-01-01

    We study how modularity of the human brain changes as children develop into adults. Theory suggests that modularity can enhance the response function of a networked system subject to changing external stimuli. Thus, greater cognitive performance might be achieved for more modular neural activity, and modularity might likely increase as children develop. The value of modularity calculated from fMRI data is observed to increase during childhood development and peak in young adulthood. Head moti...

  20. Intra-cranial recordings of brain activity during language production.

    Science.gov (United States)

    Llorens, Anaïs; Trébuchon, Agnès; Liégeois-Chauvel, Catherine; Alario, F-Xavier

    2011-01-01

    Recent findings in the neurophysiology of language production have provided a detailed description of the brain network underlying this behavior, as well as some indications about the timing of operations. Despite their invaluable utility, these data generally suffer from limitations either in terms of temporal resolution, or in terms of spatial localization. In addition, studying the neural basis of speech is complicated by the presence of articulation artifacts such as electro-myographic activity that interferes with the neural signal. These difficulties are virtually absent in a powerful albeit much less frequent methodology, namely the recording of intra-cranial brain activity (intra-cranial electroencephalography). Such recordings are only possible under very specific clinical circumstances requiring functional mapping before brain surgery, most notably in patients that suffer from pharmaco-resistant epilepsy. Here we review the research conducted with this methodology in the field of language production, with explicit consideration of its advantages and drawbacks. The available evidence is shown to be diverse, both in terms of the tasks and the cognitive processes tested and in terms of the brain localizations being studied. Still, the review provides valuable information for characterizing the dynamics of the neural events occurring in the language production network. Following modality specific activities (in auditory or visual cortices), there is a convergence of activity in superior temporal sulcus, which is a plausible neural correlate of phonological encoding processes. Later, between 500 and 800 ms, inferior frontal gyrus (around Broca's area) is involved. Peri-rolandic areas are recruited in the two modalities relatively early (200-500 ms window), suggesting a very early involvement of (pre-) motor processes. We discuss how some of these findings may be at odds with conclusions drawn from available meta-analysis of language production studies.

  1. Implicit socioemotional modulation of working memory brain activity in schizophrenia

    OpenAIRE

    Bolden, Khalima Alicia

    2016-01-01

    The neural substrate of interactions of working memory (WM) with socio-emotional processing is poorly understood in schizophrenia. This study builds on published papers using a delayed match to sample design to study the interaction of WM load with type of distracter (socially relevant faces vs. socially irrelevant geometric designs [FvG]) presented briefly during the WM maintenance period. Based on previously published findings, we hypothesize: (1) The FvG difference in brain activity in th...

  2. Practice Induces Function-Specific Changes in Brain Activity

    OpenAIRE

    Tamar R van Raalten; Ramsey, Nick F; Jeff Duyn; Jansma, Johan M.

    2008-01-01

    BACKGROUND: Practice can have a profound effect on performance and brain activity, especially if a task can be automated. Tasks that allow for automatization typically involve repeated encoding of information that is paired with a constant response. Much remains unknown about the effects of practice on encoding and response selection in an automated task. METHODOLOGY: To investigate function-specific effects of automatization we employed a variant of a Sternberg task with optimized separation...

  3. Intra-cranial recordings of brain activity during language production

    Directory of Open Access Journals (Sweden)

    Anais eLlorens

    2011-12-01

    Full Text Available Recent findings in the neurophysiology of language production have provided a detailed description of the brain network underlying this behavior, as well as some indications about the timing of operations. Despite their invaluable utility, these data generally suffer from limitations either in terms of temporal resolution, or in terms of spatial localization. In addition, studying the neural basis of speech is complicated by the presence of articulation artifacts such as electro-myographic activity that interferes with the neural signal. These difficulties are virtually absent in a powerful albeit much less frequent methodology, namely the recording of intra-cranial brain activity (iEEG. Such recordings are only possible under very specific clinical circumstances requiring functional mapping before brain surgery, most notably patients that suffer for pharmaco-resistant epilepsy. Here we review the research conducted with this methodology in the field of language production, with explicit consideration of its advantages and drawbacks. The available evidence is shown to be diverse, both in terms of the tasks and cognitive processes tested and in terms of the brain localizations being studied. Still, the review provides valuable information for characterizing the dynamics of the neural events occurring in the language production network. Following modality specific activities (in auditory or visual cortices, there is a convergence of activity in superior temporal sulcus, which is a plausible neural correlate of phonological encoding processes. Later, between 500 and 800 ms, inferior frontal gyrus (around Broca's area is involved. Peri-rolandic areas are recruited in the two modalities relatively early (200-500 ms window, suggesting a very early involvement of (pre- motor processes. We discuss how some of these findings may be at odds with conclusions drawn from available meta-analysis of language production.

  4. Aberrant activity in degenerated retinas revealed by electrical imaging

    Directory of Open Access Journals (Sweden)

    Günther eZeck

    2016-02-01

    Full Text Available In this review I present and discuss the current understanding of aberrant electrical activity found in the ganglion cell layer (GCL of rod-degenerated (rd mouse retinas. The reported electrophysiological properties revealed by electrical imaging using high-density microelectrode arrays can be subdivided between spiking activity originating from retinal ganglion cells (RGCs and local field potentials reflecting strong trans-membrane currents within the GCL. RGCs in rod-degenerated retinas show increased and rhythmic spiking compared to age-matched wild-type retinas. Fundamental spiking frequencies range from 5 to 15 Hz in various mouse models. The rhythmic RGC spiking is driven by a presynaptic network comprising AII amacrine and bipolar cells. In the healthy retina this rhythm-generating circuit is inhibited by photoreceptor input. A unique physiological feature of rd retinas is rhythmic local field potentials (LFP manifested as spatially-restricted low-frequency (5–15 Hz voltage changes. Their spatiotemporal characterization revealed propagation and correlation with RGC spiking. LFPs rely on gap-junctional coupling and are shaped by glycinergic and by GABAergic transmission. The aberrant RGC spiking and LFPs provide a simple readout of the functionality of the remaining retinal circuitry which can be used in the development of improved vision restoration strategies.

  5. Physical activity, fitness, glucose homeostasis, and brain morphology in twins.

    Science.gov (United States)

    Rottensteiner, Mirva; Leskinen, Tuija; Niskanen, Eini; Aaltonen, Sari; Mutikainen, Sara; Wikgren, Jan; Heikkilä, Kauko; Kovanen, Vuokko; Kainulainen, Heikki; Kaprio, Jaakko; Tarkka, Ina M; Kujala, Urho M

    2015-03-01

    The main aim of the present study (FITFATTWIN) was to investigate how physical activity level is associated with body composition, glucose homeostasis, and brain morphology in young adult male monozygotic twin pairs discordant for physical activity. From a population-based twin cohort, we systematically selected 10 young adult male monozygotic twin pairs (age range, 32-36 yr) discordant for leisure time physical activity during the past 3 yr. On the basis of interviews, we calculated a mean sum index for leisure time and commuting activity during the past 3 yr (3-yr LTMET index expressed as MET-hours per day). We conducted extensive measurements on body composition (including fat percentage measured by dual-energy x-ray absorptiometry), glucose homeostasis including homeostatic model assessment index and insulin sensitivity index (Matsuda index, calculated from glucose and insulin values from an oral glucose tolerance test), and whole brain magnetic resonance imaging for regional volumetric analyses. According to pairwise analysis, the active twins had lower body fat percentage (P = 0.029) and homeostatic model assessment index (P = 0.031) and higher Matsuda index (P = 0.021) compared with their inactive co-twins. Striatal and prefrontal cortex (subgyral and inferior frontal gyrus) brain gray matter volumes were larger in the nondominant hemisphere in active twins compared with those in inactive co-twins, with a statistical threshold of P physical activity is associated with improved glucose homeostasis and modulation of striatum and prefrontal cortex gray matter volume, independent of genetic background. The findings may contribute to later reduced risk of type 2 diabetes and mobility limitations.

  6. Recent Electric Propulsion Development Activities for NASA Science Missions

    Science.gov (United States)

    Pencil, Eric J.

    2009-01-01

    valve concept, as well as a pressure control module, which will regulate pressure from the propellant tank. Cross-platform component standardization and simplification are being investigated through the Standard Architecture task to reduce first user costs for implementing electric propulsion systems. Progress on current hardware development, recent test activities and future plans are discussed.

  7. Fatty Acids, Antioxidants and Physical Activity in Brain Aging

    Directory of Open Access Journals (Sweden)

    Hércules Rezende Freitas

    2017-11-01

    Full Text Available Polyunsaturated fatty acids and antioxidants are important mediators in the central nervous system. Lipid derivatives may control the production of proinflammatory agents and regulate NF-κB activity, microglial activation, and fatty acid oxidation; on the other hand, antioxidants, such as glutathione and ascorbate, have been shown to signal through transmitter receptors and protect against acute and chronic oxidative stress, modulating the activity of different signaling pathways. Several authors have investigated the role of these nutrients in the brains of the young and the aged in degenerative diseases such as Alzheimer’s and Parkinson’s, and during brain aging due to adiposity- and physical inactivity-mediated metabolic disturbances, chronic inflammation, and oxidative stress. Through a literature review, we aimed to highlight recent data on the role of adiposity, fatty acids, antioxidants, and physical inactivity in the pathophysiology of the brain and in the molecular mechanisms of senescence. Data indicate the complexity and necessity of endogenous/dietary antioxidants for the maintenance of redox status and the control of neuroglial signaling under stress. Recent studies also indicate that omega-3 and -6 fatty acids act in a competitive manner to generate mediators for energy metabolism, influencing feeding behavior, neural plasticity, and memory during aging. Finding pharmacological or dietary resources that mitigate or prevent neurodegenerative affections continues to be a great challenge and requires additional effort from researchers, clinicians, and nutritionists in the field.

  8. Acquisitions in the Electricity Sector: Active vs. Passive Owners

    Energy Technology Data Exchange (ETDEWEB)

    Nese, Gjermund

    2002-07-01

    The starting point of this paper is a mixed oligopoly market consisting of n privately owned profit maximizing firms and 1 state-owned welfare maximizing firm. Motivated by the trend of mergers and acquisitions in the liberalized electricity markets, and by the debate about public or private ownership, the paper looks at two cases. In Case 1, the state-owned company acquires an ownership share in one of the private companies. In Case 2, the state-owned company is partially privatised. The paper focuses on differences in generated quantities and social surplus, depending on whether the investors behind the acquisitions are behaving as active or passive owners. One result shows that in the case of partial privatization, passive ownership provides the highest total industry generation, while active ownership induces maximum social surplus. (author)

  9. Consciousness as a global property of brain dynamic activity

    Science.gov (United States)

    Mateos, D. M.; Wennberg, R.; Guevara, R.; Perez Velazquez, J. L.

    2017-12-01

    We seek general principles of the structure of the cellular collective activity associated with conscious awareness. Can we obtain evidence for features of the optimal brain organization that allows for adequate processing of stimuli and that may guide the emergence of cognition and consciousness? Analyzing brain recordings in conscious and unconscious states, we followed initially the classic approach in physics when it comes to understanding collective behaviours of systems composed of a myriad of units: the assessment of the number of possible configurations (microstates) that the system can adopt, for which we use a global entropic measure associated with the number of connected brain regions. Having found maximal entropy in conscious states, we then inspected the microscopic nature of the configurations of connections using an adequate complexity measure and found higher complexity in states characterized not only by conscious awareness but also by subconscious cognitive processing, such as sleep stages. Our observations indicate that conscious awareness is associated with maximal global (macroscopic) entropy and with the short time scale (microscopic) complexity of the configurations of connected brain networks in pathological unconscious states (seizures and coma), but the microscopic view captures the high complexity in physiological unconscious states (sleep) where there is information processing. As such, our results support the global nature of conscious awareness, as advocated by several theories of cognition. We thus hope that our studies represent preliminary steps to reveal aspects of the structure of cognition that leads to conscious awareness.

  10. Effects of mobile phone emissions on human brain activity and sleep variables.

    Science.gov (United States)

    Hamblin, D L; Wood, A W

    2002-08-01

    To compare the findings of the main studies that have examined the effects of GSM mobile phone radiofrequency emissions on human brain activity and sleep variables. Fourteen published studies reporting on human brain electrical activity measurements during and/or after such radiofrequency emissions were identified and compared. Although, in general, outcomes have been inconsistent and comparison between individual studies is difficult, enhanced electroencephalogram alpha-band power has been noted in several of the studies, a phenomenon also observed in some animal studies. Performance decrements observed in some recent extremely low frequency studies are consistent with enhanced alpha-band power, highlighting the possible role of extremely low frequency fields associated with battery current in mobile phone handsets. However, more complex cognitive tasks appear to show improved performance in relation to mobile phone exposure. Significant cognitive effects have been reported using both modulated and unmodulated radiofrequency carriers. The possibility of putative effects being due to extremely low frequency demodulation is therefore unlikely. There are no obvious associations between the site of exposure and regions of the brain from which effects are reported or implied. Lastly, radiofrequency effects have been reported to occur both during exposure and up to 1 h or so after cessation of exposure.

  11. How to trust a perfect stranger: predicting initial trust behavior from resting-state brain-electrical connectivity.

    Science.gov (United States)

    Hahn, Tim; Notebaert, Karolien; Anderl, Christine; Teckentrup, Vanessa; Kaßecker, Anja; Windmann, Sabine

    2015-06-01

    Reciprocal exchanges can be understood as the updating of an initial belief about a partner. This initial level of trust is essential when it comes to establishing cooperation with an unknown partner, as cooperation cannot arise without a minimum of trust not justified by previous successful exchanges with this partner. Here we demonstrate the existence of a representation of the initial trust level before an exchange with a partner has occurred. Specifically, we can predict the Investor's initial investment--i.e. his initial level of trust toward the unknown trustee in Round 1 of a standard 10-round Trust Game-from resting-state functional connectivity data acquired several minutes before the start of the Trust Game. Resting-state functional connectivity is, however, not significantly associated with the level of trust in later rounds, potentially mirroring the updating of the initial belief about the partner. Our results shed light on how the initial level of trust is represented. In particular, we show that a person's initial level of trust is, at least in part, determined by brain electrical activity acquired well before the beginning of an exchange. © The Author (2014). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

  12. Can Neural Activity Propagate by Endogenous Electrical Field?

    Science.gov (United States)

    Qiu, Chen; Shivacharan, Rajat S.; Zhang, Mingming

    2015-01-01

    It is widely accepted that synaptic transmissions and gap junctions are the major governing mechanisms for signal traveling in the neural system. Yet, a group of neural waves, either physiological or pathological, share the same speed of ∼0.1 m/s without synaptic transmission or gap junctions, and this speed is not consistent with axonal conduction or ionic diffusion. The only explanation left is an electrical field effect. We tested the hypothesis that endogenous electric fields are sufficient to explain the propagation with in silico and in vitro experiments. Simulation results show that field effects alone can indeed mediate propagation across layers of neurons with speeds of 0.12 ± 0.09 m/s with pathological kinetics, and 0.11 ± 0.03 m/s with physiologic kinetics, both generating weak field amplitudes of ∼2–6 mV/mm. Further, the model predicted that propagation speed values are inversely proportional to the cell-to-cell distances, but do not significantly change with extracellular resistivity, membrane capacitance, or membrane resistance. In vitro recordings in mice hippocampi produced similar speeds (0.10 ± 0.03 m/s) and field amplitudes (2.5–5 mV/mm), and by applying a blocking field, the propagation speed was greatly reduced. Finally, osmolarity experiments confirmed the model's prediction that cell-to-cell distance inversely affects propagation speed. Together, these results show that despite their weak amplitude, electric fields can be solely responsible for spike propagation at ∼0.1 m/s. This phenomenon could be important to explain the slow propagation of epileptic activity and other normal propagations at similar speeds. SIGNIFICANCE STATEMENT Neural activity (waves or spikes) can propagate using well documented mechanisms such as synaptic transmission, gap junctions, or diffusion. However, the purpose of this paper is to provide an explanation for experimental data showing that neural signals can propagate by means other than synaptic

  13. Localization of brain activation by umami taste in humans.

    Science.gov (United States)

    Nakamura, Yuko; Goto, Tazuko K; Tokumori, Kenji; Yoshiura, Takashi; Kobayashi, Koji; Nakamura, Yasuhiko; Honda, Hiroshi; Ninomiya, Yuzo; Yoshiura, Kazunori

    2011-08-11

    There are no credible data to support the notion that individual taste qualities have dedicated pathways leading from the tongue to the end of the pathway in the brain. Moreover, the insular cortex is activated not only by taste but also by non-taste information from oral stimuli. These responses are invariably excitatory, and it is difficult to determine whether they are sensory, motor, or proprioceptive in origin. Furthermore, umami is a more unfamiliar and complex taste than other basic tastes. Considering these issues, it may be effective to minimize somatosensory stimuli, oral movement, and psychological effects in a neuroimaging study to elicit cerebral activity by pure umami on the human tongue. For this purpose, we developed an original taste delivery system for functional magnetic resonance imaging (fMRI) studies for umami. Then, we compared the results produced by two authorized models, namely, the block design model and event-related design model, to decide the appropriate model for detecting activation by umami. Activation by the umami taste was well localized in the insular cortex using our new system and block design model analysis. The peaks of the activated areas in the middle insular cortex by umami were very close to another prototypical taste quality (salty). Although we have to carefully interpret the perceiving intensities and brain activations by taste from different sessions, this study design might be effective for detecting the accession area in the cortex of pure umami taste on the tongue. Copyright © 2011 Elsevier B.V. All rights reserved.

  14. The influence of low-grade glioma on resting state oscillatory brain activity: a magnetoencephalography study

    NARCIS (Netherlands)

    Bosma, I.; Stam, C. J.; Douw, L.; Bartolomei, F.; Heimans, J. J.; van Dijk, B. W.; Postma, T. J.; Klein, M.; Reijneveld, J. C.

    2008-01-01

    In the present MEG-study, power spectral analysis of oscillatory brain activity was used to compare resting state brain activity in both low-grade glioma (LGG) patients and healthy controls. We hypothesized that LGG patients show local as well as diffuse slowing of resting state brain activity

  15. Retrieving binary answers using whole-brain activity pattern classification

    Directory of Open Access Journals (Sweden)

    Norberto Eiji Nawa

    2015-12-01

    Full Text Available Multivariate pattern analysis (MVPA has been successfully employed to advance our understanding of where and how information regarding different mental states is represented in the human brain, bringing new insights into how these states come to fruition, and providing a promising complement to the mass-univariate approach. Here, we employed MVPA to classify whole-brain activity patterns occurring in single fMRI scans, in order to retrieve binary answers from experiment participants. Five healthy volunteers performed two types of mental task while in the MRI scanner: counting down numbers and recalling positive autobiographical events. Data from these runs were used to train individual machine learning based classifiers that predicted which mental task was being performed based on the voxel-based brain activity patterns. On a different day, the same volunteers reentered the scanner and listened to six statements (e.g., the month you were born is an odd number, and were told to countdown numbers if the statement was true (yes or recall positive events otherwise (no. The previously trained classifiers were then used to assign labels (yes/no to the scans collected during the 24-second response periods following each one of the statements. Mean classification accuracies at the single scan level were in the range of 73.6% to 80.8%, significantly above chance for all participants. When applying a majority vote on the scans within each response period, i.e., the most frequent label (yes/no in the response period becomes the answer to the previous statement, 5.0 to 5.8 sentences, out of 6, were correctly classified in each one of the runs, on average. These results indicate that binary answers can be retrieved from whole-brain activity patterns, suggesting that MVPA provides an alternative way to establish basic communication with unresponsive patients when other techniques are not successful.

  16. Spatiotemporal dynamics of large-scale brain activity

    Science.gov (United States)

    Neuman, Jeremy

    Understanding the dynamics of large-scale brain activity is a tough challenge. One reason for this is the presence of an incredible amount of complexity arising from having roughly 100 billion neurons connected via 100 trillion synapses. Because of the extremely high number of degrees of freedom in the nervous system, the question of how the brain manages to properly function and remain stable, yet also be adaptable, must be posed. Neuroscientists have identified many ways the nervous system makes this possible, of which synaptic plasticity is possibly the most notable one. On the other hand, it is vital to understand how the nervous system also loses stability, resulting in neuropathological diseases such as epilepsy, a disease which affects 1% of the population. In the following work, we seek to answer some of these questions from two different perspectives. The first uses mean-field theory applied to neuronal populations, where the variables of interest are the percentages of active excitatory and inhibitory neurons in a network, to consider how the nervous system responds to external stimuli, self-organizes and generates epileptiform activity. The second method uses statistical field theory, in the framework of single neurons on a lattice, to study the concept of criticality, an idea borrowed from physics which posits that in some regime the brain operates in a collectively stable or marginally stable manner. This will be examined in two different neuronal networks with self-organized criticality serving as the overarching theme for the union of both perspectives. One of the biggest problems in neuroscience is the question of to what extent certain details are significant to the functioning of the brain. These details give rise to various spatiotemporal properties that at the smallest of scales explain the interaction of single neurons and synapses and at the largest of scales describe, for example, behaviors and sensations. In what follows, we will shed some

  17. Endurance training improves skeletal muscle electrical activity in active COPD patients.

    Science.gov (United States)

    Gosselin, Nadège; Lambert, Karen; Poulain, Magali; Martin, Anne; Préfaut, Christian; Varray, Alain

    2003-12-01

    The effect of endurance training on muscle electrical activity during general exercise testing was investigated in physically active patients with chronic obstructive pulmonary disease (COPD). Before and after rehabilitation, patients performed identical incremental exercise tests. Pulmonary gas exchange, venous lactate and pyruvate concentrations, and the quadriceps electromyographic signal were sampled every minute throughout exercise testing. Three weeks of rehabilitation increased exercise capacity without modifying pulmonary function. M-wave amplitude, root mean square (RMS) of electromyographic activity, and RMS/oxygen uptake were increased significantly during post-rehabilitation testing at the same exercise intensity compared to pre-rehabilitation. Median frequency was significantly lower after training. These modifications reflect greater muscle excitability, greater muscle activation for the same level of exercise, and higher recruitment of slow-twitch fibers. Pulmonary rehabilitation in active COPD patients may normalize the electrical activity of skeletal muscles during incremental dynamic exercise. The electromyographic signal confirms neuromuscular changes after endurance training.

  18. Spatio-temporal dynamics of kind versus hostile intentions in the human brain: An electrical neuroimaging study.

    Science.gov (United States)

    Wang, Yiwen; Huang, Liang; Zhang, Wei; Zhang, Zhen; Cacioppo, Stephanie

    2015-01-01

    Neuroscience research suggests that inferring neutral intentions of other people recruits a specific brain network within the inferior fronto-parietal action observation network as well as a putative social network including brain areas subserving theory of mind, such as the posterior superior temporal sulcus (pSTS), the temporo-parietal junction (TPJ), and also the anterior cingulate cortex (ACC). Recent studies on harmful intentions have refined this network by showing the specific involvement of the ACC, amygdala, and ventromedial prefrontal cortex (vmPFC) in early stages (within 200 ms) of information processing. However, the functional dynamics for kind intentions within and among these networks remains unclear. To address this question, we measured electrical brain activity from 18 healthy adult participants while they were performing an intention inference task with three different types of intentions: kind, hostile and non-interactive. Electrophysiological results revealed that kind intentions were characterized by significantly larger peak amplitudes of N2 over the frontal sites than those for hostile and non-interactive intentions. On the other hand, there were no significant differences between hostile and non-interactive intentions at N2. The source analysis suggested that the vicinity of the left cingulate gyrus contributed to the N2 effect by subtracting the kindness condition from the non-interactive condition within 250-350 ms. At a later stage (i.e., during the 270-500 ms epoch), the peak amplitude of the P3 over the parietal sites and the right hemisphere was significantly larger for hostile intentions compared to the kind and non-interactive intentions. No significant differences were observed at P3 between kind and non-interactive intentions. The source analysis showed that the vicinity of the left anterior cingulate cortex contributed to the P3 effect by subtracting the hostility condition from the non-interactive condition within 450-550 ms

  19. Activated and deactivated functional brain areas in the Deqi state

    OpenAIRE

    Huang, Yong; Zeng, Tongjun; Zhang, Guifeng; Li, Ganlong; Lu, Na; Lai, Xinsheng; Lu, Yangjia; Chen, Jiarong

    2012-01-01

    We compared the activities of functional regions of the brain in the Deqi versus non-Deqi state, as reported by physicians and subjects during acupuncture. Twelve healthy volunteers received sham and true needling at the Waiguan (TE5) acupoint. Real-time cerebral functional MRI showed that compared with non-sensation after sham needling, true needling activated Brodmann areas 3, 6, 8, 9, 10, 11, 13, 20, 21, 37, 39, 40, 43, and 47, the head of the caudate nucleus, the parahippocampal gyrus, th...

  20. Mapping brain activity at scale with cluster computing.

    Science.gov (United States)

    Freeman, Jeremy; Vladimirov, Nikita; Kawashima, Takashi; Mu, Yu; Sofroniew, Nicholas J; Bennett, Davis V; Rosen, Joshua; Yang, Chao-Tsung; Looger, Loren L; Ahrens, Misha B

    2014-09-01

    Understanding brain function requires monitoring and interpreting the activity of large networks of neurons during behavior. Advances in recording technology are greatly increasing the size and complexity of neural data. Analyzing such data will pose a fundamental bottleneck for neuroscience. We present a library of analytical tools called Thunder built on the open-source Apache Spark platform for large-scale distributed computing. The library implements a variety of univariate and multivariate analyses with a modular, extendable structure well-suited to interactive exploration and analysis development. We demonstrate how these analyses find structure in large-scale neural data, including whole-brain light-sheet imaging data from fictively behaving larval zebrafish, and two-photon imaging data from behaving mouse. The analyses relate neuronal responses to sensory input and behavior, run in minutes or less and can be used on a private cluster or in the cloud. Our open-source framework thus holds promise for turning brain activity mapping efforts into biological insights.

  1. Genome-wide association study of working memory brain activation.

    Science.gov (United States)

    Blokland, Gabriëlla A M; Wallace, Angus K; Hansell, Narelle K; Thompson, Paul M; Hickie, Ian B; Montgomery, Grant W; Martin, Nicholas G; McMahon, Katie L; de Zubicaray, Greig I; Wright, Margaret J

    2017-05-01

    In a population-based genome-wide association (GWA) study of n-back working memory task-related brain activation, we extracted the average percent BOLD signal change (2-back minus 0-back) from 46 regions-of-interest (ROIs) in functional MRI scans from 863 healthy twins and siblings. ROIs were obtained by creating spheres around group random effects analysis local maxima, and by thresholding a voxel-based heritability map of working memory brain activation at 50%. Quality control for test-retest reliability and heritability of ROI measures yielded 20 reliable (r>0.7) and heritable (h(2)>20%) ROIs. For GWA analysis, the cohort was divided into a discovery (n=679) and replication (n=97) sample. No variants survived the stringent multiple-testing-corrected genome-wide significance threshold (pmemory. Variants identified here may be relevant to (the susceptibility to) common disorders affecting brain function. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Brain activation of eye movements in subjects with refractive error

    Science.gov (United States)

    Nelles, Gereon; Pscherer, Anja; de Greiff, Armin; Esser, Joachim

    2010-01-01

    Purpose Recent functional magnetic resonance imaging (fMRI) studies have described reorganized activation of the oculomotor and visual cortex after focal brain lesions. These studies are based on comparison with healthy individuals who may have a very heterogenous refractive error. The influence of refractive error on the cortical control of an oculomotor task such as a prosaccade trial, however, is unknown. Methods To investigate the influence of visual acuity on changes of cortical oculomotor control, we studied the representation of visually guided prosaccades in nine subjects with refractive error and 11 normally sighted subjects using fMRI. Correction of refractive error was not allowed during fMRI. Differences in activation between rest and saccades as well as between subjects with refractive error vs subjects with normal vision were assessed with statistical parametric mapping. Results In both groups, activation of a frontoparietal network was observed. Subjects with refractive errors showed increased activation compared to normally sighted subjects, with overactivation in bilateral frontal and parietal eye fields, supplementary eye fields, as well as in the bilateral extrastriate cortex. Conclusions This group of subjects with refractive error showed increased activation in an extended oculomotor and visual network to maintain performance during simple prosaccades. This observation underlines the importance of using appropriate control groups in fMRI-studies after brain lesions. PMID:28539763

  3. Modafinil enhances alerting-related brain activity in attention networks.

    Science.gov (United States)

    Ikeda, Yumiko; Funayama, Takuya; Tateno, Amane; Fukayama, Haruhisa; Okubo, Yoshiro; Suzuki, Hidenori

    2017-07-01

    Modafinil is a wake-promoting agent and has been reported to be effective in improving attention in patients with attentional disturbance. However, neural substrates underlying the modafinil effects on attention are not fully understood. We employed a functional magnetic resonance imaging (fMRI) study with the attention network test (ANT) task in healthy adults and examined which networks of attention are mainly affected by modafinil and which neural substrates are responsible for the drug effects. We used a randomized placebo-controlled within-subjects cross-over design. Twenty-three healthy adults participated in two series of an fMRI study, taking either a placebo or modafinil. The participants performed the ANT task, which is designed to measure three distinct attentional networks, alerting, orienting, and executive control, during the fMRI scanning. The effects of modafinil on behavioral performance and regional brain activity were analyzed. We found that modafinil enhanced alerting performance and showed greater alerting network activity in the left middle and inferior occipital gyri as compared with the placebo. The brain activations in the occipital regions were positively correlated with alerting performance. Modafinil enhanced alerting performance and increased activation in the occipital lobe in the alerting network possibly relevant to noradrenergic activity during the ANT task. The present study may provide a rationale for the treatment of patients with distinct symptoms of impaired attention.

  4. Convolutional virtual electric field for image segmentation using active contours.

    Directory of Open Access Journals (Sweden)

    Yuanquan Wang

    Full Text Available Gradient vector flow (GVF is an effective external force for active contours; however, it suffers from heavy computation load. The virtual electric field (VEF model, which can be implemented in real time using fast Fourier transform (FFT, has been proposed later as a remedy for the GVF model. In this work, we present an extension of the VEF model, which is referred to as CONvolutional Virtual Electric Field, CONVEF for short. This proposed CONVEF model takes the VEF model as a convolution operation and employs a modified distance in the convolution kernel. The CONVEF model is also closely related to the vector field convolution (VFC model. Compared with the GVF, VEF and VFC models, the CONVEF model possesses not only some desirable properties of these models, such as enlarged capture range, u-shape concavity convergence, subject contour convergence and initialization insensitivity, but also some other interesting properties such as G-shape concavity convergence, neighboring objects separation, and noise suppression and simultaneously weak edge preserving. Meanwhile, the CONVEF model can also be implemented in real-time by using FFT. Experimental results illustrate these advantages of the CONVEF model on both synthetic and natural images.

  5. Metrology in electricity and magnetism: EURAMET activities today and tomorrow

    Science.gov (United States)

    Piquemal, F.; Jeckelmann, B.; Callegaro, L.; Hällström, J.; Janssen, T. J. B. M.; Melcher, J.; Rietveld, G.; Siegner, U.; Wright, P.; Zeier, M.

    2017-10-01

    Metrology dedicated to electricity and magnetism has changed considerably in recent years. It encompasses almost all modern scientific, industrial, and societal challenges, e.g. the revision of the International System of Units, the profound transformation of industry, changes in energy use and generation, health, and environment, as well as nanotechnologies (including graphene and 2D materials) and quantum engineering. Over the same period, driven by the globalization of worldwide trade, the Mutual Recognition Arrangement (referred to as the CIPM MRA) was set up. As a result, the regional metrology organizations (RMOs) of national metrology institutes have grown in significance. EURAMET is the European RMO and has been very prominent in developing a strategic research agenda (SRA) and has established a comprehensive research programme. This paper reviews the highlights of EURAMET in electrical metrology within the European Metrology Research Programme and its main contributions to the CIPM MRA. In 2012 EURAMET undertook an extensive roadmapping exercise for proposed activities for the next decade which will also be discussed in this paper. This work has resulted in a new SRA of the second largest European funding programme: European Metrology Programme for Innovation and Research.

  6. Immature pattern of brain activity in Rett syndrome

    DEFF Research Database (Denmark)

    Nielsen, J B; Friberg, L; Lou, H

    1990-01-01

    Seven girls with Rett syndrome, a progressive degenerative encephalopathy affecting girls, were studied with single photon emission computed tomography and compared with an aged-matched control group of nine normal children. Global cerebral blood flow was significantly lower in Rett syndrome (54 vs...... 69 mL/100 g per minute), and the flows in prefrontal and temporoparietal association regions of the telencephalon were markedly reduced, whereas the primary sensorimotor regions were relatively spared. The flow distribution in Rett syndrome is very similar to the distribution of brain metabolic...... activity in infants of a few months of age. The abnormal regional cerebral blood flow distribution most likely reflects the widespread functional disturbances in the brain of patients with Rett syndrome, whereas computed tomographic and neuropathologic examination only reveal slight changes when compared...

  7. Exposure to static electric fields leads to changes in biogenic amine levels in the brains of Drosophila

    Science.gov (United States)

    Newland, Philip L.; Al Ghamdi, Mesfer S.; Sharkh, Suleiman; Aonuma, Hitoshi; Jackson, Christopher W.

    2015-01-01

    Natural and anthropogenic static electric fields are commonly found in the environment and can have both beneficial and harmful effects on many animals. Here, we asked how the fruitfly responds to these fields and what the consequences of exposure are on the levels of biogenic amines in the brain. When given a choice in a Y-tube bioassay Drosophila avoided electric fields, and the greater the field strength the more likely Drosophila were to avoid it. By comparing wild-type flies, flies with wings surgically removed and vestigial winged flies we found that the presence of intact wings was necessary to produce avoidance behaviour. We also show that Coulomb forces produced by electric fields physically lift excised wings, with the smaller wings of males being raised by lower field strengths than larger female wings. An analysis of neurochemical changes in the brains showed that a suite of changes in biogenic amine levels occurs following chronic exposure. Taken together we conclude that physical movements of the wings are used by Drosophila in generating avoidance behaviour and are accompanied by changes in the levels of amines in the brain, which in turn impact on behaviour. PMID:26224706

  8. Brain mechanical property measurement using MRE with intrinsic activation

    Science.gov (United States)

    Weaver, John B.; Pattison, Adam J.; McGarry, Matthew D.; Perreard, Irina M.; Swienckowski, Jessica G.; Eskey, Clifford J.; Lollis, S. Scott; Paulsen, Keith D.

    2012-11-01

    , termed intrinsic activation, produces sufficient motion to allow mechanical properties to be recovered. The poroelastic model is more consistent with the measured data from brain at low frequencies than the linear elastic model. Intrinsic activation allows MRE to be performed without a device shaking the head so the patient notices no differences between it and the other sequences in an MR examination.

  9. Cell Proliferation, Migration, and Neurogenesis in the Adult Brain of the Pulse Type Weakly Electric Fish, Gymnotus omarorum

    Science.gov (United States)

    Olivera-Pasilio, Valentina; Lasserre, Moira; Castelló, María E.

    2017-01-01

    Adult neurogenesis, an essential mechanism of brain plasticity, enables brain development along postnatal life, constant addition of new neurons, neuronal turnover, and/or regeneration. It is amply distributed but negatively modulated during development and along evolution. Widespread cell proliferation, high neurogenic, and regenerative capacities are considered characteristics of teleost brains during adulthood. These anamniotes are promising models to depict factors that modulate cell proliferation, migration, and neurogenesis, and might be intervened to promote brain plasticity in mammals. Nevertheless, the migration path of derived cells to their final destination was not studied in various teleosts, including most weakly electric fish. In this group adult brain morphology is attributed to sensory specialization, involving the concerted evolution of peripheral electroreceptors and electric organs, encompassed by the evolution of neural networks involved in electrosensory information processing. In wave type gymnotids adult brain morphology is proposed to result from lifelong region specific cell proliferation and neurogenesis. Consistently, pulse type weakly electric gymnotids and mormyrids show widespread distribution of proliferation zones that persists in adulthood, but their neurogenic potential is still unknown. Here we studied the migration process and differentiation of newborn cells into the neuronal phenotype in the pulse type gymnotid Gymnotus omarorum. Pulse labeling of S-phase cells with 5-Chloro-2′-deoxyuridine thymidine followed by 1 to 180 day survivals evidenced long distance migration of newborn cells from the rostralmost telencephalic ventricle to the olfactory bulb, and between layers of all cerebellar divisions. Shorter migration appeared in the tectum opticum and torus semicircularis. In many brain regions, derived cells expressed early neuronal markers doublecortin (chase: 1–30 days) and HuC/HuD (chase: 7–180 days). Some newborn

  10. Cell Proliferation, Migration, and Neurogenesis in the Adult Brain of the Pulse Type Weakly Electric Fish, Gymnotus omarorum

    Directory of Open Access Journals (Sweden)

    Valentina Olivera-Pasilio

    2017-08-01

    Full Text Available Adult neurogenesis, an essential mechanism of brain plasticity, enables brain development along postnatal life, constant addition of new neurons, neuronal turnover, and/or regeneration. It is amply distributed but negatively modulated during development and along evolution. Widespread cell proliferation, high neurogenic, and regenerative capacities are considered characteristics of teleost brains during adulthood. These anamniotes are promising models to depict factors that modulate cell proliferation, migration, and neurogenesis, and might be intervened to promote brain plasticity in mammals. Nevertheless, the migration path of derived cells to their final destination was not studied in various teleosts, including most weakly electric fish. In this group adult brain morphology is attributed to sensory specialization, involving the concerted evolution of peripheral electroreceptors and electric organs, encompassed by the evolution of neural networks involved in electrosensory information processing. In wave type gymnotids adult brain morphology is proposed to result from lifelong region specific cell proliferation and neurogenesis. Consistently, pulse type weakly electric gymnotids and mormyrids show widespread distribution of proliferation zones that persists in adulthood, but their neurogenic potential is still unknown. Here we studied the migration process and differentiation of newborn cells into the neuronal phenotype in the pulse type gymnotid Gymnotus omarorum. Pulse labeling of S-phase cells with 5-Chloro-2′-deoxyuridine thymidine followed by 1 to 180 day survivals evidenced long distance migration of newborn cells from the rostralmost telencephalic ventricle to the olfactory bulb, and between layers of all cerebellar divisions. Shorter migration appeared in the tectum opticum and torus semicircularis. In many brain regions, derived cells expressed early neuronal markers doublecortin (chase: 1–30 days and HuC/HuD (chase: 7–180 days

  11. The Relationship Between Brain Oscillatory Activity and Therapeutic Effectiveness of Transcranial Magnetic Stimulation in the Treatment of Major Depressive Disorder

    Directory of Open Access Journals (Sweden)

    Andrew Francis Leuchter

    2013-02-01

    Full Text Available Major Depressive Disorder (MDD is marked by disturbances in brain functional connectivity. This connectivity is modulated by rhythmic oscillations of brain electrical activity, which enable coordinated functions across brain regions. Oscillatory activity plays a central role in regulating thinking and memory, mood, cerebral blood flow, and neurotransmitter levels, and restoration of normal oscillatory patterns is associated with effective treatment of MDD. Repetitive Transcranial Magnetic Stimulation (rTMS is a robust treatment for MDD, but the mechanism of action (MOA of its benefits for mood disorders remains incompletely understood. Benefits of rTMS have been tied to enhanced neuroplasticity in specific brain pathways. We summarize here the evidence that rTMS entrains and resets thalamocortical oscillators, normalizes regulation and facilitates reemergence of intrinsic cerebral rhythms, and through this mechanism restores normal brain function. This entrainment and resetting may be a critical step in engendering neuroplastic changes and the antidepressant effects of rTMS. It may be possible to modify the method of rTMS administration to enhance this mechanism of action and achieve better antidepressant effectiveness. We propose that rTMS can be administered: 1 synchronized to a patient’s individual alpha rhythm (IAF, or synchronized rTMS (sTMS; 2 as a low magnetic field strength sinusoidal wave form; and, 3 broadly to multiple brain areas simultaneously. We present here the theory and evidence indicating that these modifications could enhance the therapeutic effectiveness of rTMS for the treatment of MDD.

  12. Memory for performed and observed activities following traumatic brain injury.

    Science.gov (United States)

    Wright, Matthew J; Wong, Andrew L; Obermeit, Lisa C; Woo, Ellen; Schmitter-Edgecombe, Maureen; Fuster, Joaquín M

    2014-01-01

    Traumatic brain injury (TBI) is associated with deficits in memory for the content of completed activities. However, TBI groups have shown variable memory for the temporal order of activities. We sought to clarify the conditions under which temporal order memory for activities is intact following TBI. Additionally, we evaluated activity source memory and the relationship between activity memory and functional outcome in TBI participants. Thus, we completed a study of activity memory with 18 severe TBI survivors and 18 healthy age- and education-matched comparison participants. Both groups performed eight activities and observed eight activities that were fashioned after routine daily tasks. Incidental encoding conditions for activities were utilized. The activities were drawn from two counterbalanced lists, and both performance and observation were randomly determined and interspersed. After all of the activities were completed, content memory (recall and recognition), source memory (conditional source identification), and temporal order memory (correlation between order reconstruction and actual order) for the activities were assessed. Functional ability was assessed via the Community Integration Questionnaire (CIQ). In terms of content memory, TBI participants recalled and recognized fewer activities than comparison participants. Recognition of performed and observed activities was strongly associated with social integration on the CIQ. There were no between- or within-group differences in temporal order or source memory, although source memory performances were near ceiling. The findings were interpreted as suggesting that temporal order memory following TBI is intact under conditions of both purposeful activity completion and incidental encoding, and that activity memory is related to functional outcomes following TBI.

  13. The effects of electrical stimulation or an electrolytic lesion in the mediodorsal thalamus of the rat on survival, body weight, food intake and running activity in the activity-based anorexia model

    OpenAIRE

    Luyten, Laura; Welkenhuysen, Marleen; Van Kuyck, Kris; Fieuws, Steffen; Das, John; Sciot, Raf; Nuttin, Bart

    2009-01-01

    The glucose metabolism in the mediodorsal thalamus (MD) is increased in rats in the activity-based anorexia (ABA) model. In patients, electrical stimulation in hyperactive brain regions reduced symptoms in e.g. major depressive disorder and cluster headache. In two blinded randomised controlled experiments, we therefore examined the effects of high-frequency electrical stimulation and an electrolytic lesion in the MD in a validated rat model for anorexia nervosa. The ABA model was successfull...

  14. Promoting Active Learning in Electrical Engineering Basic Studies

    Directory of Open Access Journals (Sweden)

    Anu Lehtovuori

    2013-05-01

    Full Text Available Active learning, project-based teaching, and student collaboration are current trends in engineering education. Incorporating these have also been the goal of the basic studies development project EPOP started at the Aalto University School of Electrical Engineering in 2011. In the project, two obligatory basic courses in circuit analysis and electromagnetic field theory have been taught using interactive engagement during the spring of 2012. This paper presents the implementation of the teaching, including methods and evaluation with several concrete examples. As a result of the novel teaching, motivation and the engagement of students were at a high level during the whole course and learning results were better than those of the students participating the traditional lecture course.

  15. Brain activity associated with selective attention, divided attention and distraction.

    Science.gov (United States)

    Salo, Emma; Salmela, Viljami; Salmi, Juha; Numminen, Jussi; Alho, Kimmo

    2017-06-01

    Top-down controlled selective or divided attention to sounds and visual objects, as well as bottom-up triggered attention to auditory and visual distractors, has been widely investigated. However, no study has systematically compared brain activations related to all these types of attention. To this end, we used functional magnetic resonance imaging (fMRI) to measure brain activity in participants performing a tone pitch or a foveal grating orientation discrimination task, or both, distracted by novel sounds not sharing frequencies with the tones or by extrafoveal visual textures. To force focusing of attention to tones or gratings, or both, task difficulty was kept constantly high with an adaptive staircase method. A whole brain analysis of variance (ANOVA) revealed fronto-parietal attention networks for both selective auditory and visual attention. A subsequent conjunction analysis indicated partial overlaps of these networks. However, like some previous studies, the present results also suggest segregation of prefrontal areas involved in the control of auditory and visual attention. The ANOVA also suggested, and another conjunction analysis confirmed, an additional activity enhancement in the left middle frontal gyrus related to divided attention supporting the role of this area in top-down integration of dual task performance. Distractors expectedly disrupted task performance. However, contrary to our expectations, activations specifically related to the distractors were found only in the auditory and visual cortices. This suggests gating of the distractors from further processing perhaps due to strictly focused attention in the current demanding discrimination tasks. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Classification of types of stuttering symptoms based on brain activity.

    Directory of Open Access Journals (Sweden)

    Jing Jiang

    Full Text Available Among the non-fluencies seen in speech, some are more typical (MT of stuttering speakers, whereas others are less typical (LT and are common to both stuttering and fluent speakers. No neuroimaging work has evaluated the neural basis for grouping these symptom types. Another long-debated issue is which type (LT, MT whole-word repetitions (WWR should be placed in. In this study, a sentence completion task was performed by twenty stuttering patients who were scanned using an event-related design. This task elicited stuttering in these patients. Each stuttered trial from each patient was sorted into the MT or LT types with WWR put aside. Pattern classification was employed to train a patient-specific single trial model to automatically classify each trial as MT or LT using the corresponding fMRI data. This model was then validated by using test data that were independent of the training data. In a subsequent analysis, the classification model, just established, was used to determine which type the WWR should be placed in. The results showed that the LT and the MT could be separated with high accuracy based on their brain activity. The brain regions that made most contribution to the separation of the types were: the left inferior frontal cortex and bilateral precuneus, both of which showed higher activity in the MT than in the LT; and the left putamen and right cerebellum which showed the opposite activity pattern. The results also showed that the brain activity for WWR was more similar to that of the LT and fluent speech than to that of the MT. These findings provide a neurological basis for separating the MT and the LT types, and support the widely-used MT/LT symptom grouping scheme. In addition, WWR play a similar role as the LT, and thus should be placed in the LT type.

  17. Classification of Types of Stuttering Symptoms Based on Brain Activity

    Science.gov (United States)

    Jiang, Jing; Lu, Chunming; Peng, Danling; Zhu, Chaozhe; Howell, Peter

    2012-01-01

    Among the non-fluencies seen in speech, some are more typical (MT) of stuttering speakers, whereas others are less typical (LT) and are common to both stuttering and fluent speakers. No neuroimaging work has evaluated the neural basis for grouping these symptom types. Another long-debated issue is which type (LT, MT) whole-word repetitions (WWR) should be placed in. In this study, a sentence completion task was performed by twenty stuttering patients who were scanned using an event-related design. This task elicited stuttering in these patients. Each stuttered trial from each patient was sorted into the MT or LT types with WWR put aside. Pattern classification was employed to train a patient-specific single trial model to automatically classify each trial as MT or LT using the corresponding fMRI data. This model was then validated by using test data that were independent of the training data. In a subsequent analysis, the classification model, just established, was used to determine which type the WWR should be placed in. The results showed that the LT and the MT could be separated with high accuracy based on their brain activity. The brain regions that made most contribution to the separation of the types were: the left inferior frontal cortex and bilateral precuneus, both of which showed higher activity in the MT than in the LT; and the left putamen and right cerebellum which showed the opposite activity pattern. The results also showed that the brain activity for WWR was more similar to that of the LT and fluent speech than to that of the MT. These findings provide a neurological basis for separating the MT and the LT types, and support the widely-used MT/LT symptom grouping scheme. In addition, WWR play a similar role as the LT, and thus should be placed in the LT type. PMID:22761887

  18. Unmasking local activity within local field potentials (LFPs) by removing distal electrical signals using independent component analysis.

    Science.gov (United States)

    Whitmore, Nathan W; Lin, Shih-Chieh

    2016-05-15

    Local field potentials (LFPs) are commonly thought to reflect the aggregate dynamics in local neural circuits around recording electrodes. However, we show that when LFPs are recorded in awake behaving animals against a distal reference on the skull as commonly practiced, LFPs are significantly contaminated by non-local and non-neural sources arising from the reference electrode and from movement-related noise. In a data set with simultaneously recorded LFPs and electroencephalograms (EEGs) across multiple brain regions while rats perform an auditory oddball task, we used independent component analysis (ICA) to identify signals arising from electrical reference and from volume-conducted noise based on their distributed spatial pattern across multiple electrodes and distinct power spectral features. These sources of distal electrical signals collectively accounted for 23-77% of total variance in unprocessed LFPs, as well as most of the gamma oscillation responses to the target stimulus in EEGs. Gamma oscillation power was concentrated in volume-conducted noise and was tightly coupled with the onset of licking behavior, suggesting a likely origin of muscle activity associated with body movement or orofacial movement. The removal of distal signal contamination also selectively reduced correlations of LFP/EEG signals between distant brain regions but not within the same region. Finally, the removal of contamination from distal electrical signals preserved an event-related potential (ERP) response to auditory stimuli in the frontal cortex and also increased the coupling between the frontal ERP amplitude and neuronal activity in the basal forebrain, supporting the conclusion that removing distal electrical signals unmasked local activity within LFPs. Together, these results highlight the significant contamination of LFPs by distal electrical signals and caution against the straightforward interpretation of unprocessed LFPs. Our results provide a principled approach to

  19. EEG reactions of the human brain in the gradient magnetic field zone of the active geological fault (pilot study)

    Science.gov (United States)

    Pobachenko, S. V.; Shitov, A. V.; Grigorjev, P. E.; Sokolov, M. V.; Zubrilkin, A. I.; Vypiraylo, D. N.; Solovjev, A. V.

    2016-12-01

    This paper presents the results of experimental studies of the dynamics of the functional state of a person within the zone of an active geological fault characterized by abnormal spatial distribution of the magnetic- field vector values. It is shown that these geophysical modifications have a pronounced effect on the fluctuations of the electrical activity of the human brain. When the person gets into a zone with abnormal levels of gradient magnetic field in the absence of any subjective sensations, a nonspecific orientation activation reaction is observed, which is characterized by a significant increase in the levels of peak performance in key functional EEG frequency bands.

  20. Changes in music tempo entrain movement related brain activity.

    Science.gov (United States)

    Daly, Ian; Hallowell, James; Hwang, Faustina; Kirke, Alexis; Malik, Asad; Roesch, Etienne; Weaver, James; Williams, Duncan; Miranda, Eduardo; Nasuto, Slawomir J

    2014-01-01

    The neural mechanisms of music listening and appreciation are not yet completely understood. Based on the apparent relationship between the beats per minute (tempo) of music and the desire to move (for example feet tapping) induced while listening to that music it is hypothesised that musical tempo may evoke movement related activity in the brain. Participants are instructed to listen, without moving, to a large range of musical pieces spanning a range of styles and tempos during an electroencephalogram (EEG) experiment. Event-related desynchronisation (ERD) in the EEG is observed to correlate significantly with the variance of the tempo of the musical stimuli. This suggests that the dynamics of the beat of the music may induce movement related brain activity in the motor cortex. Furthermore, significant correlations are observed between EEG activity in the alpha band over the motor cortex and the bandpower of the music in the same frequency band over time. This relationship is observed to correlate with the strength of the ERD, suggesting entrainment of motor cortical activity relates to increased ERD strength.

  1. Enhancing performance of a motor imagery based brain-computer interface by incorporating electrical stimulation-induced SSSEP

    Science.gov (United States)

    Yi, Weibo; Qiu, Shuang; Wang, Kun; Qi, Hongzhi; Zhao, Xin; He, Feng; Zhou, Peng; Yang, Jiajia; Ming, Dong

    2017-04-01

    Objective. We proposed a novel simultaneous hybrid brain-computer interface (BCI) by incorporating electrical stimulation into a motor imagery (MI) based BCI system. The goal of this study was to enhance the overall performance of an MI-based BCI. In addition, the brain oscillatory pattern in the hybrid task was also investigated. Approach. 64-channel electroencephalographic (EEG) data were recorded during MI, selective attention (SA) and hybrid tasks in fourteen healthy subjects. In the hybrid task, subjects performed MI with electrical stimulation which was applied to bilateral median nerve on wrists simultaneously. Main results. The hybrid task clearly presented additional steady-state somatosensory evoked potential (SSSEP) induced by electrical stimulation with MI-induced event-related desynchronization (ERD). By combining ERD and SSSEP features, the performance in the hybrid task was significantly better than in both MI and SA tasks, achieving a ~14% improvement in total relative to the MI task alone and reaching ~89% in mean classification accuracy. On the contrary, there was no significant enhancement obtained in performance while separate ERD feature was utilized in the hybrid task. In terms of the hybrid task, the performance using combined feature was significantly better than using separate ERD or SSSEP feature. Significance. The results in this work validate the feasibility of our proposed approach to form a novel MI-SSSEP hybrid BCI outperforming a conventional MI-based BCI through combing MI with electrical stimulation.

  2. Toward the Restoration of Hand Use to a Paralyzed Monkey: Brain-Controlled Functional Electrical Stimulation of Forearm Muscles

    Science.gov (United States)

    Pohlmeyer, Eric A.; Oby, Emily R.; Perreault, Eric J.; Solla, Sara A.; Kilgore, Kevin L.; Kirsch, Robert F.; Miller, Lee E.

    2009-01-01

    Loss of hand use is considered by many spinal cord injury survivors to be the most devastating consequence of their injury. Functional electrical stimulation (FES) of forearm and hand muscles has been used to provide basic, voluntary hand grasp to hundreds of human patients. Current approaches typically grade pre-programmed patterns of muscle activation using simple control signals, such as those derived from residual movement or muscle activity. However, the use of such fixed stimulation patterns limits hand function to the few tasks programmed into the controller. In contrast, we are developing a system that uses neural signals recorded from a multi-electrode array implanted in the motor cortex; this system has the potential to provide independent control of multiple muscles over a broad range of functional tasks. Two monkeys were able to use this cortically controlled FES system to control the contraction of four forearm muscles despite temporary limb paralysis. The amount of wrist force the monkeys were able to produce in a one-dimensional force tracking task was significantly increased. Furthermore, the monkeys were able to control the magnitude and time course of the force with sufficient accuracy to track visually displayed force targets at speeds reduced by only one-third to one-half of normal. Although these results were achieved by controlling only four muscles, there is no fundamental reason why the same methods could not be scaled up to control a larger number of muscles. We believe these results provide an important proof of concept that brain-controlled FES prostheses could ultimately be of great benefit to paralyzed patients with injuries in the mid-cervical spinal cord. PMID:19526055

  3. Toward the restoration of hand use to a paralyzed monkey: brain-controlled functional electrical stimulation of forearm muscles.

    Directory of Open Access Journals (Sweden)

    Eric A Pohlmeyer

    2009-06-01

    Full Text Available Loss of hand use is considered by many spinal cord injury survivors to be the most devastating consequence of their injury. Functional electrical stimulation (FES of forearm and hand muscles has been used to provide basic, voluntary hand grasp to hundreds of human patients. Current approaches typically grade pre-programmed patterns of muscle activation using simple control signals, such as those derived from residual movement or muscle activity. However, the use of such fixed stimulation patterns limits hand function to the few tasks programmed into the controller. In contrast, we are developing a system that uses neural signals recorded from a multi-electrode array implanted in the motor cortex; this system has the potential to provide independent control of multiple muscles over a broad range of functional tasks. Two monkeys were able to use this cortically controlled FES system to control the contraction of four forearm muscles despite temporary limb paralysis. The amount of wrist force the monkeys were able to produce in a one-dimensional force tracking task was significantly increased. Furthermore, the monkeys were able to control the magnitude and time course of the force with sufficient accuracy to track visually displayed force targets at speeds reduced by only one-third to one-half of normal. Although these results were achieved by controlling only four muscles, there is no fundamental reason why the same methods could not be scaled up to control a larger number of muscles. We believe these results provide an important proof of concept that brain-controlled FES prostheses could ultimately be of great benefit to paralyzed patients with injuries in the mid-cervical spinal cord.

  4. Patterned electrical activity modulates sodium channel expression in sensory neurons.

    Science.gov (United States)

    Klein, Joshua P; Tendi, Elisabetta A; Dib-Hajj, Sulayman D; Fields, R Douglas; Waxman, Stephen G

    2003-10-15

    Peripheral nerve injury induces changes in the level of gene expression for sodium channels Nav1.3, Nav1.8, and Nav1.9 within dorsal root ganglion (DRG) neurons, which may contribute to the development of hyperexcitability, ectopic neuronal discharge, and neuropathic pain. The mechanism of this change in sodium channel expression is unclear. Decreased availability of neurotrophic factors following axotomy contributes to these changes in gene transcription, but the question of whether changes in intrinsic neuronal activity levels alone can trigger changes in the expression of these sodium channels has not been addressed. We examined the effect of electrical stimulation on the expression of Nav1.3, Nav1.8, and Nav1.9 by using cultured embryonic mouse sensory neurons under conditions in which nerve growth factor (NGF) was not limiting. Expression of Nav1.3 was not significantly changed following stimulation. In contrast, we observed activity-dependent down-regulation of Nav1.8 and Nav1.9 mRNA and protein levels after stimulation, as demonstrated by quantitative polymerase chain reaction and immunocytochemistry. These results show that a change in neuronal activity can alter the expression of sodium channel genes in a subtype-specific manner, via a mechanism independent of NGF withdrawal. Copyright 2003 Wiley-Liss, Inc.

  5. The impact of large structural brain changes in chronic stroke patients on the electric field caused by transcranial brain stimulation

    DEFF Research Database (Denmark)

    Minjoli, Sena; Saturnino, Guilherme B.; Blicher, Jakob Udby

    2017-01-01

    . Realistic head models containing large cortical and subcortical stroke lesions in the right parietal cortex were created using MR images of two patients. For TMS, the electric field of a double coil was simulated using the finite-element method. Systematic variations of the coil position relative...... to the lesion were tested. For TDCS, the finite-element method was used to simulate a standard approach with two electrode pads, and the position of one electrode was systematically varied. For both TMS and TDCS, the lesion caused electric field " hot spots" in the cortex. However, these maxima were...... aimed to characterize the impact of these changes on the spatial distribution of the electric field generated by both TBS methods. In addition to confirming the safety of TBS in the presence of large stroke-related structural changes, our aim was to clarify whether targeted stimulation is still possible...

  6. The impact of large structural brain changes in chronic stroke patients on the electric field caused by transcranial brain stimulation

    DEFF Research Database (Denmark)

    Minjoli, Sena; Saturnino, Guilherme B.; Blicher, Jakob Udby

    2017-01-01

    aimed to characterize the impact of these changes on the spatial distribution of the electric field generated by both TBS methods. In addition to confirming the safety of TBS in the presence of large stroke-related structural changes, our aim was to clarify whether targeted stimulation is still possible....... Realistic head models containing large cortical and subcortical stroke lesions in the right parietal cortex were created using MR images of two patients. For TMS, the electric field of a double coil was simulated using the finite-element method. Systematic variations of the coil position relative...... to the lesion were tested. For TDCS, the finite-element method was used to simulate a standard approach with two electrode pads, and the position of one electrode was systematically varied. For both TMS and TDCS, the lesion caused electric field " hot spots" in the cortex. However, these maxima were...

  7. Involvement of the middle frontal gyrus in language switching as revealed by electrical stimulation mapping and functional magnetic resonance imaging in bilingual brain tumor patients.

    Science.gov (United States)

    Sierpowska, Joanna; Fernandez-Coello, Alejandro; Gomez-Andres, Alba; Camins, Àngels; Castañer, Sara; Juncadella, Montserrat; Gabarrós, Andreu; Rodríguez-Fornells, Antoni

    2018-02-01

    Neural basis of language switching and the cognitive models of bilingualism remain controversial. We explored the functional neuroanatomy of language switching implementing a new multimodal protocol assessing neuropsychological, functional magnetic resonance and intraoperative electrical stimulation mapping results. A prospective series of 9 Spanish-Catalan bilingual candidates for awake brain surgery underwent a specific language switching paradigm implemented both before and after surgery, throughout the electrical stimulation procedure and during functional magnetic resonance both pre- and postoperatively. All patients were harboring left-hemispheric intrinsic brain lesions and were presenting functional language-related activations within the affected hemisphere. Language functional maps were reconstructed on the basis of the intraoperative electrical stimulation results and compared to the functional magnetic resonance findings. Single language-naming sites (Spanish and Catalan), as well as language switching naming sites were detected by electrical stimulation mapping in 8 patients (in one patient only Spanish related sites were detected). Single naming points outnumbered the switching points and did not overlap with each other. Within the frontal lobe, the single language naming sites were found significantly more frequently within the inferior frontal gyrus as compared to the middle frontal gyrus [X 2 (1) = 20.3, p language switching and their neuropsychological scores did not differ significantly from the pre-surgical examinations. Our results suggest a functional division of the frontal cortex between naming and language switching functions, supporting that non-language specific cognitive control prefrontal regions (middle frontal gyrus) are essential to maintain an effective communication together with the classical language-related sites (inferior frontal gyrus). Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Cortical activity in the left and right hemispheres during language-related brain functions

    DEFF Research Database (Denmark)

    Lassen, N A; Larsen, B

    1980-01-01

    The blood flow to a given brain region increases as the level of neural activity is augmented. Hence mapping of variations in regional cerebral blood flow affords a means of imaging the activity of various brain regions during various types of brain work. The paper summarizes the patterns...

  9. The influence of low-grade glioma on resting state oscillatory brain activity: a magnetoencephalography study

    NARCIS (Netherlands)

    Bosma, I.; Stam, C.; Douw, L.; Bartolomei, F.; Heimans, J.; Dijk, van B.; Postma, T.; Klein, M.; Reijneveld, J.

    2008-01-01

    Purpose: In the present MEG-study, power spectral analysis of oscillatory brain activity was used to compare resting state brain activity in both low-grade glioma (LGG) patients and healthy controls. We hypothesized that LGG patients show local as well as diffuse slowing of resting state brain

  10. Biological role of sialosyl transferase activity in rat brain

    Energy Technology Data Exchange (ETDEWEB)

    Durrie, R.P. Jr.

    1986-01-01

    The purpose of this dissertation is to obtain new evidence that will support or refute the existence of an ecto sialosyltransferse activity (STase) that has been described in the synaptic plasma membrane (SPM). This STase has been proposed to transfer sialic acid (NANA) to endogenous SPM gangliosides. Preparations of rat brain synaptosomes were assayed for STase by incubation with CMP-(/sup 14/C)NANA, and measuring radioactivity transferred to the endogenous gangliosides. The activity was found to be 0.84 pmoles NANA transferred per mg protein per hour. The product specificity for STase was determined by the incorporation of label into individual ganglioside species. Subfractions were produced from rat brain that were enriched in Golgi membranes, synaptosomes, and SPM as judged by EM morphology and marker enzymes. The Golgi fraction had over 3 fold greater STase activity than synaptosomes, while SPM were enriched 2.5 fold over the synaptosomes from which they came. The labeling pattern of endogenous gangliosides was quite different by the Golgi STase. An unknown compound in the ganglioside extracts was specifically labeled, but gangliosides were not labeled with specificity by the Golgi transferase. The synaptosomal and SPM labeling patterns were identical and were characterized by GD3 specificity. Therefore the STase of SPM is not due to Golgi contamination. Intact neurons were assayed for STase by the use of brain cortical slices. Slices incubated that labeled CMP-NANA (available for cell surface reactions) produced the GD3-specific labeling pattern. These results suggest that the GD3-specific sialosyltransferase is a cell surface ecto-enzyme.

  11. Brain state dependent activity in the cortex and thalamus.

    Science.gov (United States)

    McCormick, David A; McGinley, Matthew J; Salkoff, David B

    2015-04-01

    Cortical and thalamocortical activity is highly state dependent, varying between patterns that are conducive to accurate sensory-motor processing, to states in which the brain is largely off-line and generating internal rhythms irrespective of the outside world. The generation of rhythmic activity occurs through the interaction of stereotyped patterns of connectivity together with intrinsic membrane and synaptic properties. One common theme in the generation of rhythms is the interaction of a positive feedback loop (e.g., recurrent excitation) with negative feedback control (e.g., inhibition, adaptation, or synaptic depression). The operation of these state-dependent activities has wide ranging effects from enhancing or blocking sensory-motor processing to the generation of pathological rhythms associated with psychiatric or neurological disorders. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Patterns of regional brain activity in alcohol-dependent subjects.

    Science.gov (United States)

    Hayden, Elizabeth P; Wiegand, Ryan E; Meyer, Eric T; Bauer, Lance O; O'connor, Sean J; Nurnberger, John I; Chorlian, David B; Porjesz, Bernice; Begleiter, Henri

    2006-12-01

    Electroencephalographic (EEG) measures of hemispheric asymmetry in anterior brain activity have been related to a variety of indices of psychopathology and emotionality. However, little is known about patterns of frontal asymmetry in alcohol-dependent (AD) samples. It is also unclear whether psychiatric comorbidity in AD subjects accounts for additional variance in frontal asymmetry, beyond a diagnosis of AD alone. We compared 193 AD subjects with 108 control subjects on resting brain activity in anterior and posterior regions, as indexed by asymmetries in alpha band power in the left and right hemispheres. Within the AD group alone, we examined whether comorbid major depressive disorder (MDD) or antisocial personality disorder (ASPD) had effects on regional asymmetry. Compared with control subjects, AD subjects exhibited lower left, relative to right, cortical activation in anterior regions. Evidence that comorbidity in AD subjects accounted for further variance in EEG asymmetry was mixed; AD subjects with comorbid ASPD were not significantly different from those without ASPD, while AD subjects with a lifetime history of MDD showed less asymmetry in anterior regions than those without MDD. Our findings indicate that AD subjects exhibit a pattern of frontal asymmetry similar to that found in other psychiatric groups. Results examining the effects of comorbidity in AD on EEG asymmetry were inconclusive. The implications of our findings for future work are described.

  13. On the Modeling of Electrical Effects Experienced by Space Explorers During Extra Vehicular Activities: Intracorporal Currents, Resistances, and Electric Fields

    Science.gov (United States)

    Cela, Carlos J.; Loizos, Kyle; Lazzi, Gianluca; Hamilton, Douglas; Lee, Raphael C.

    2011-01-01

    Recent research has shown that space explorers engaged in Extra Vehicular Activities (EVAs) may be exposed, under certain conditions, to undesired electrical currents. This work focuses on determining whether these undesired induced electrical currents could be responsible for involuntary neuromuscular activity in the subjects, possibly caused by either large diameter peripheral nerve activation or reflex activity from cutaneous afferent stimulation. An efficient multiresolution variant of the admittance method along with a millimeter-resolution model of a male human body were used to calculate induced electric fields, resistance between contact electrodes used to simulate the potential exposure condition, and currents induced in the human body model. Results show that, under realistic exposure conditions using a 15V source, current density magnitudes and total current injected are well above previously reported startle reaction thresholds. This indicates that, under the considered conditions, the subjects could experience involuntary motor response.

  14. Longitudinal, transcranial measurement of functional activation in the rat brain by diffuse correlation spectroscopy.

    Science.gov (United States)

    Blanco, Igor; Zirak, Peyman; Dragojević, Tanja; Castellvi, Clara; Durduran, Turgut; Justicia, Carles

    2017-10-01

    Neural activity is an important biomarker for the presence of neurodegenerative diseases, cerebrovascular alterations, and brain trauma; furthermore, it is a surrogate marker for treatment effects. These pathologies may occur and evolve in a long time-period, thus, noninvasive, transcutaneous techniques are necessary to allow a longitudinal follow-up. In the present work, we have customized noninvasive, transcutaneous, diffuse correlation spectroscopy (DCS) to localize changes in cerebral blood flow (CBF) induced by neural activity. We were able to detect changes in CBF in the somatosensory cortex by using a model of electrical forepaw stimulation in rats. The suitability of DCS measurements for longitudinal monitoring was demonstrated by performing multiple sessions with the same animals at different ages (from 6 to 18 months). In addition, functional DCS has been cross-validated by comparison with functional magnetic resonance imaging (fMRI) in the same animals in a subset of the time-points. The overall results obtained with transcutaneous DCS demonstrates that it can be utilized in longitudinal studies safely and reproducibly to locate changes in CBF induced by neural activity in the small animal brain.

  15. Electrocommunication signals alone are sufficient to increase neurogenesis in the brain of adult electric fish, Apteronotus leptorhynchus.

    Science.gov (United States)

    Dunlap, Kent D; McCarthy, Elizabeth A; Jashari, Denisa

    2008-10-01

    Social interaction can have profound influences on the structure of the adult brain, but little is known about the precise stimulus feature found within social interaction that induces such brain plasticity. We examined the effects of social stimuli on cell addition and radial glial fiber formation in the brains of adult electric fish. These fish communicate primarily through weak, quasi-sinusoidal electric signals. Fish were housed in isolation, paired with another fish or exposed to only the electrocommunication signals of another fish for 7 days. After 3 days of exposure to these stimulus conditions, fish were injected with bromodeoxyuridine (BrdU) to mark newborn cells. We sacrificed the fish 4 days after BrdU injection and used immunohistochemistry to measure cell addition (BrdU+), the fraction of added cells that differentiated into neurons (BrdU+/NeuroTrace+) and the density of radial glia fibers (vimentin+) in the periventricular zone of the diencephalon. Fish that were exposed only to the electrocommunication signals of another fish and no other social stimuli had equivalent levels of cell addition and radial glial fiber density to fish that were housed with full social interaction and higher levels than fish housed in isolation. About 60% of the added cells differentiated into neurons; this fraction did not differ among treatment groups. Artificial sine wave electrical stimuli that mimicked electrocommunication signals were ineffective in increasing cell addition and glia fiber formation above those found in isolated fish. Thus, stimuli through a single modality are sufficient for inducing this brain plasticity, but the waveform or dynamic features of communication signals are crucial for the effect. (c) 2008 Wiley Periodicals, Inc.

  16. Brain activity and desire for Internet video game play.

    Science.gov (United States)

    Han, Doug Hyun; Bolo, Nicolas; Daniels, Melissa A; Arenella, Lynn; Lyoo, In Kyoon; Renshaw, Perry F

    2011-01-01

    Recent studies have suggested that the brain circuitry mediating cue-induced desire for video games is similar to that elicited by cues related to drugs and alcohol. We hypothesized that desire for Internet video games during cue presentation would activate similar brain regions to those that have been linked with craving for drugs or pathologic gambling. This study involved the acquisition of diagnostic magnetic resonance imaging and functional magnetic resonance imaging data from 19 healthy male adults (age, 18-23 years) following training and a standardized 10-day period of game play with a specified novel Internet video game, "War Rock" (K2 Network, Irvine, CA). Using segments of videotape consisting of 5 contiguous 90-second segments of alternating resting, matched control, and video game-related scenes, desire to play the game was assessed using a 7-point visual analogue scale before and after presentation of the videotape. In responding to Internet video game stimuli, compared with neutral control stimuli, significantly greater activity was identified in left inferior frontal gyrus, left parahippocampal gyrus, right and left parietal lobe, right and left thalamus, and right cerebellum (false discovery rate Internet video game showed significantly greater activity in right medial frontal lobe, right and left frontal precentral gyrus, right parietal postcentral gyrus, right parahippocampal gyrus, and left parietal precuneus gyrus. Controlling for total game time, reported desire for the Internet video game in the subjects who played more Internet video game was positively correlated with activation in right medial frontal lobe and right parahippocampal gyrus. The present findings suggest that cue-induced activation to Internet video game stimuli may be similar to that observed during cue presentation in persons with substance dependence or pathologic gambling. In particular, cues appear to commonly elicit activity in the dorsolateral prefrontal, orbitofrontal

  17. Brain activity and desire for internet video game play

    Science.gov (United States)

    Han, Doug Hyun; Bolo, Nicolas; Daniels, Melissa A.; Arenella, Lynn; Lyoo, In Kyoon; Renshaw, Perry F.

    2010-01-01

    Objective Recent studies have suggested that the brain circuitry mediating cue induced desire for video games is similar to that elicited by cues related to drugs and alcohol. We hypothesized that desire for internet video games during cue presentation would activate similar brain regions to those which have been linked with craving for drugs or pathological gambling. Methods This study involved the acquisition of diagnostic MRI and fMRI data from 19 healthy male adults (ages 18–23 years) following training and a standardized 10-day period of game play with a specified novel internet video game, “War Rock” (K-network®). Using segments of videotape consisting of five contiguous 90-second segments of alternating resting, matched control and video game-related scenes, desire to play the game was assessed using a seven point visual analogue scale before and after presentation of the videotape. Results In responding to internet video game stimuli, compared to neutral control stimuli, significantly greater activity was identified in left inferior frontal gyrus, left parahippocampal gyrus, right and left parietal lobe, right and left thalamus, and right cerebellum (FDR video game (MIGP) cohort showed significantly greater activity in right medial frontal lobe, right and left frontal pre-central gyrus, right parietal post-central gyrus, right parahippocampal gyrus, and left parietal precuneus gyrus. Controlling for total game time, reported desire for the internet video game in the MIGP cohort was positively correlated with activation in right medial frontal lobe and right parahippocampal gyrus. Discussion The present findings suggest that cue-induced activation to internet video game stimuli may be similar to that observed during cue presentation in persons with substance dependence or pathological gambling. In particular, cues appear to commonly elicit activity in the dorsolateral prefrontal, orbitofrontal cortex, parahippocampal gyrus, and thalamus. PMID:21220070

  18. Peripheral administration of lipopolysaccharide induces activation of microglial cells in rat brain

    NARCIS (Netherlands)

    Buttini, M; Limonta, S; Boddeke, HWGM

    Using immunocytochemistry with monoclonal antibodies against surface immunomolecules and Griffonia simplicifolia lectin histochemistry, the microglial cell reaction in rat brain was studied after intravenous injection of lipopolysaccharide (LPS). Activation of microglial cells throughout the brain

  19. Active control for performance enhancement of electrically controlled rotor

    Directory of Open Access Journals (Sweden)

    Lu Yang

    2015-10-01

    Full Text Available Electrically controlled rotor (ECR system has the potential to enhance the rotor performance by applying higher harmonic flap inputs. In order to explore the feasibility and effectiveness for ECR performance enhancement using closed-loop control method, firstly, an ECR rotor performance analysis model based on helicopter flight dynamic model is established, which can reflect the performance characteristics of ECR helicopter at high advance ratio. Based on the simulation platform, an active control method named adaptive T-matrix algorithm is adopted to explore the feasibility and effectiveness for ECR performance enhancement. The simulation results verify the effectiveness of this closed-loop control method. For the sample ECR helicopter, about 3% rotor power reduction is obtained with the optimum 2/rev flap inputs at the advance ratio of 0.34. And through analyzing the distributions of attack of angle and drag in rotor disk, the underlying physical essence of ECR power reduction is cleared. Furthermore, the influence of the key control parameters, including convergence factor and weighting matrix, on the effectiveness of closed-loop control for ECR performance enhancement is explored. Some useful results are summarized, which can be used to direct the future active control law design of ECR performance enhancement.

  20. Mind maps in service of the mental brain activity

    OpenAIRE

    JOSIPOVIĆ JELIĆ, ŽELJKA; Demarin, Vida; Šoljan, Ivana

    2014-01-01

    Tony Buzan is the creator of the mind maps who based his mnemonic techniques of brain mapping on the terms of awareness and wide brain functionality as well as on the ability of memorizing, reading and creativity. He conceived the idea that regular practice improves brain functions but he also introduced radiant thinking and mental literacy. One of the last enormous neuroscience ventures is to clarify the brain complexity and mind and to get a complete insight into the mental brain acti...

  1. Multi-dimensional dynamics of human electromagnetic brain activity

    Directory of Open Access Journals (Sweden)

    Tetsuo eKida

    2016-01-01

    Full Text Available Magnetoencephalography (MEG and electroencephalography (EEG are invaluable neuroscientific tools for unveiling human neural dynamics in three dimensions (space, time, and frequency, which are associated with a wide variety of perceptions, cognition, and actions. MEG/EEG also provides different categories of neuronal indices including activity magnitude, connectivity, and network properties along the three dimensions. In the last 20 years, interest has increased in inter-regional connectivity and complex network properties assessed by various sophisticated scientific analyses. We herein review the definition, computation, short history, and pros and cons of connectivity and complex network (graph-theory analyses applied to MEG/EEG signals. We briefly describe recent developments in source reconstruction algorithms essential for source-space connectivity and network analyses. Furthermore, we discuss a relatively novel approach used in MEG/EEG studies to examine the complex dynamics represented by human brain activity. The correct and effective use of these neuronal metrics provides a new insight into the multi-dimensional dynamics of the neural representations of various functions in the complex human brain.

  2. Multi-Dimensional Dynamics of Human Electromagnetic Brain Activity.

    Science.gov (United States)

    Kida, Tetsuo; Tanaka, Emi; Kakigi, Ryusuke

    2015-01-01

    Magnetoencephalography (MEG) and electroencephalography (EEG) are invaluable neuroscientific tools for unveiling human neural dynamics in three dimensions (space, time, and frequency), which are associated with a wide variety of perceptions, cognition, and actions. MEG/EEG also provides different categories of neuronal indices including activity magnitude, connectivity, and network properties along the three dimensions. In the last 20 years, interest has increased in inter-regional connectivity and complex network properties assessed by various sophisticated scientific analyses. We herein review the definition, computation, short history, and pros and cons of connectivity and complex network (graph-theory) analyses applied to MEG/EEG signals. We briefly describe recent developments in source reconstruction algorithms essential for source-space connectivity and network analyses. Furthermore, we discuss a relatively novel approach used in MEG/EEG studies to examine the complex dynamics represented by human brain activity. The correct and effective use of these neuronal metrics provides a new insight into the multi-dimensional dynamics of the neural representations of various functions in the complex human brain.

  3. Targeted training modifies oscillatory brain activity in schizophrenia patients.

    Science.gov (United States)

    Popov, Tzvetan G; Carolus, Almut; Schubring, David; Popova, Petia; Miller, Gregory A; Rockstroh, Brigitte S

    2015-01-01

    Effects of both domain-specific and broader cognitive remediation protocols have been reported for neural activity and overt performance in schizophrenia (SZ). Progress is limited by insufficient knowledge of relevant neural mechanisms. Addressing neuronal signal resolution in the auditory system as a mechanism contributing to cognitive function and dysfunction in schizophrenia, the present study compared effects of two neuroplasticity-based training protocols targeting auditory-verbal or facial affect discrimination accuracy and a standard rehabilitation protocol on magnetoencephalographic (MEG) oscillatory brain activity in an auditory paired-click task. SZ were randomly assigned to either 20 daily 1-hour sessions over 4 weeks of auditory-verbal training (N = 19), similarly intense facial affect discrimination training (N = 19), or 4 weeks of treatment as usual (TAU, N = 19). Pre-training, the 57 SZ showed smaller click-induced posterior alpha power modulation than did 28 healthy comparison participants, replicating Popov et al. (2011b). Abnormally small alpha decrease 300-800 ms around S2 improved more after targeted auditory-verbal training than after facial affect training or TAU. The improvement in oscillatory brain dynamics with training correlated with improvement on a measure of verbal learning. Results replicate previously reported effects of neuroplasticity-based psychological training on oscillatory correlates of auditory stimulus differentiation, encoding, and updating and indicate specificity of cortical training effects.

  4. Covert waking brain activity reveals instantaneous sleep depth.

    Directory of Open Access Journals (Sweden)

    Scott M McKinney

    Full Text Available The neural correlates of the wake-sleep continuum remain incompletely understood, limiting the development of adaptive drug delivery systems for promoting sleep maintenance. The most useful measure for resolving early positions along this continuum is the alpha oscillation, an 8-13 Hz electroencephalographic rhythm prominent over posterior scalp locations. The brain activation signature of wakefulness, alpha expression discloses immediate levels of alertness and dissipates in concert with fading awareness as sleep begins. This brain activity pattern, however, is largely ignored once sleep begins. Here we show that the intensity of spectral power in the alpha band actually continues to disclose instantaneous responsiveness to noise--a measure of sleep depth--throughout a night of sleep. By systematically challenging sleep with realistic and varied acoustic disruption, we found that sleepers exhibited markedly greater sensitivity to sounds during moments of elevated alpha expression. This result demonstrates that alpha power is not a binary marker of the transition between sleep and wakefulness, but carries rich information about immediate sleep stability. Further, it shows that an empirical and ecologically relevant form of sleep depth is revealed in real-time by EEG spectral content in the alpha band, a measure that affords prediction on the order of minutes. This signal, which transcends the boundaries of classical sleep stages, could potentially be used for real-time feedback to novel, adaptive drug delivery systems for inducing sleep.

  5. Targeted training modifies oscillatory brain activity in schizophrenia patients

    Directory of Open Access Journals (Sweden)

    Tzvetan G. Popov

    2015-01-01

    Full Text Available Effects of both domain-specific and broader cognitive remediation protocols have been reported for neural activity and overt performance in schizophrenia (SZ. Progress is limited by insufficient knowledge of relevant neural mechanisms. Addressing neuronal signal resolution in the auditory system as a mechanism contributing to cognitive function and dysfunction in schizophrenia, the present study compared effects of two neuroplasticity-based training protocols targeting auditory–verbal or facial affect discrimination accuracy and a standard rehabilitation protocol on magnetoencephalographic (MEG oscillatory brain activity in an auditory paired-click task. SZ were randomly assigned to either 20 daily 1-hour sessions over 4 weeks of auditory–verbal training (N = 19, similarly intense facial affect discrimination training (N = 19, or 4 weeks of treatment as usual (TAU, N = 19. Pre-training, the 57 SZ showed smaller click-induced posterior alpha power modulation than did 28 healthy comparison participants, replicating Popov et al. (2011b. Abnormally small alpha decrease 300–800 ms around S2 improved more after targeted auditory–verbal training than after facial affect training or TAU. The improvement in oscillatory brain dynamics with training correlated with improvement on a measure of verbal learning. Results replicate previously reported effects of neuroplasticity-based psychological training on oscillatory correlates of auditory stimulus differentiation, encoding, and updating and indicate specificity of cortical training effects.

  6. Evaluation of cerebral electrical activity and cardiac output after patent ductus arteriosus ligation in preterm infants.

    LENUS (Irish Health Repository)

    Leslie, A T F S

    2013-11-01

    To characterize and investigate the relationship between systemic blood flow and pre- and postoperative cerebral electrical activity in preterm neonates undergoing patent ductus arteriosus (PDA) ligation.

  7. Correlation between dielectric property by dielectrophoretic levitation and growth activity of cells exposed to electric field.

    Science.gov (United States)

    Hakoda, Masaru; Hirota, Yusuke

    2013-09-01

    The purpose of this study is to develop a system analyzing cell activity by the dielectrophoresis method. Our previous studies revealed a correlation between the growth activity and dielectric property (Re[K(ω)]) of mouse hybridoma 3-2H3 cells using dielectrophoretic levitation. Furthermore, it was clarified that the differentiation activity of many stem cells could be evaluated by the Re[K(ω)] without differentiation induction. In this paper, 3-2H3 cells exposed to an alternating current (AC) electric field or a direct current (DC) electric field were cultivated, and the influence of damage by the electric field on the growth activity of the cells was examined. To evaluate the activity of the cells by measuring the Re[K(ω)], the correlation between the growth activity and the Re[K(ω)] of the cells exposed to the electric field was examined. The relations between the cell viability, growth activity, and Re[K(ω)] in the cells exposed to the AC electric field were obtained. The growth activity of the cells exposed to the AC electric field could be evaluated by the Re[K(ω)]. Furthermore, it was found that the adverse effects of the electric field on the cell viability and the growth activity were smaller in the AC electric field than the DC electric field.

  8. Transcutaneous electrical nerve stimulation attenuates CFA-induced hyperalgesia and inhibits spinal ERK1/2-COX-2 pathway activation in rats

    OpenAIRE

    Fang, Jun-Fan; Liang, Yi; Du, Jun-Ying; Fang, Jian-Qiao

    2013-01-01

    Background Transcutaneous electrical nerve stimulation (TENS) is a non-pharmacologic treatment for pain relief. In previous animal studies, TENS effectively alleviated Complete Freund?s Adjuvant (CFA)- or carrageenan-induced inflammatory pain. Although TENS is known to produce analgesia via opioid activation in the brain and at the spinal level, few reports have investigated the signal transduction pathways mediated by TENS. Prior studies have verified the importance of the activation of extr...

  9. FEATURES OF THE ALPHA ACTIVITY OF THE BRAIN ON THE BACKGROUND OF MEDITATIVEPSYCHOLOGICAL TRAINING

    Directory of Open Access Journals (Sweden)

    A. S. Yanina

    2016-01-01

    Full Text Available The aim of the study was to identify the characteristics of the alpha activity of the brain on the background of meditative psychological training, depending on experience and qualifications.Materials and methods. Examined 30 volunteers of 25-45 years old, 12 men and 18 women. Depending on the experience of meditative practices, the participants were divided into three groups: a group with no experience of meditation (beginners, group practicing Kundalini yoga in General classes (1-3 times a week – average level, and a group of professionals (yoga teachers, practicing for at least three years and having a daily practice. All participants did not had neurological and psychiatric diseases, and had no dependence on alcohol or drugs and was relatively healthy. A study was conducted of the electrical activity of the brain at rest, during and after the meditative psychological training. As a result we acquired data for the frontal, Central, occipital and temporal leads.Results. Identified a number of changes of EEG parameters in the application of meditation techniques, which depended on the experience and qualifications of the subjects. Changes of alpha activity occur in all areas of the brain with the development of meditation techniques, whereas newcomers have changes mainly in the frontal region. The index of alpha-rhythm at rest is higher in groups with experience of meditation practice. The given material allows to recommend psychological training (meditation techniques of Kundalini yoga to reduce the level of fatigue and correction of psycho-emotional excitation. 

  10. Neurotransmitters couple brain activity to subventricular zone neurogenesis

    Science.gov (United States)

    Young, Stephanie Z.; Taylor, M. Morgan; Bordey, Angélique

    2011-01-01

    Adult neurogenesis occurs in two privileged microenvironments, the hippocampal subgranular zone of the dentate gyrus and the subventricular zone (SVZ) along the lateral ventricle. This review focuses on accumulating evidence suggesting that the activity of specific brain regions or bodily states influences SVZ cell proliferation and neurogenesis. Neuromodulators such as dopamine and serotonin have been shown to have long-range effects through neuronal projections into the SVZ. Local GABA and glutamate signaling have demonstrated effects on SVZ proliferation and neurogenesis, but an extra-niche source of these neurotransmitters remains to be explored and options will be discussed. There is also accumulating evidence that diseases and bodily states such as Alzheimer's disease, seizures, sleep, and pregnancy influence SVZ cell proliferation. With such complex behavior and environmentally-driven factors that control subregion-specific activity, it will become necessary to account for overlapping roles of multiple neurotransmitter systems on neurogenesis when developing cell therapies or drug treatments. PMID:21395856

  11. Brain activation profiles during the early stages of reading acquisition.

    Science.gov (United States)

    Simos, Panagiotis G; Fletcher, Jack M; Foorman, Barbara R; Francis, David J; Castillo, Eduardo M; Davis, Robert N; Fitzgerald, Michele; Mathes, Patricia G; Denton, Carolyn; Papanicolaou, Andrew C

    2002-03-01

    In the present study, we demonstrate for the first time the presence of an aberrant brain mechanism for reading in children who have just started acquiring reading skills. Children who, at the end of kindergarten, are found to be at risk for developing reading problems display markedly different activation profiles than children who have, at this stage, already mastered important prereading skills. This aberrant profile is characterized by the lack of engagement of the left-hemisphere superior temporal region, an area normally involved in converting print into sound, and an increase in activation in the corresponding right-hemisphere region. This finding is consistent with current cognitive models of reading acquisition and dyslexia, pointing to the critical role of phonologic awareness skills in learning to read.

  12. Dynamic brain architectures in local brain activity and functional network efficiency associate with efficient reading in bilinguals.

    Science.gov (United States)

    Feng, Gangyi; Chen, Hsuan-Chih; Zhu, Zude; He, Yong; Wang, Suiping

    2015-10-01

    The human brain is organized as a dynamic network, in which both regional brain activity and inter-regional connectivity support high-level cognitive processes, such as reading. However, it is still largely unknown how the functional brain network organizes to enable fast and effortless reading processing in the native language (L1) but not in a non-proficient second language (L2), and whether the mechanisms underlying local activity are associated with connectivity dynamics in large-scale brain networks. In the present study, we combined activation-based and multivariate graph-theory analysis with functional magnetic resonance imaging data to address these questions. Chinese-English unbalanced bilinguals read narratives for comprehension in Chinese (L1) and in English (L2). Compared with L2, reading in L1 evoked greater brain activation and recruited a more globally efficient but less clustered network organization. Regions with both increased network efficiency and enhanced brain activation in L1 reading were mostly located in the fronto-temporal reading-related network (RN), whereas regions with decreased global network efficiency, increased clustering, and more deactivation in L2 reading were identified in the default mode network (DMN). Moreover, functional network efficiency was closely associated with local brain activation, and such associations were also modulated by reading efficiency in the two languages. Our results demonstrate that an economical and integrative brain network topology is associated with efficient reading, and further reveal a dynamic association between network efficiency and local activation for both RN and DMN. These findings underscore the importance of considering interregional connectivity when interpreting local BOLD signal changes in bilingual reading. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Written distractor words influence brain activity during overt picture naming.

    Science.gov (United States)

    Diaz, Michele T; Hogstrom, Larson J; Zhuang, Jie; Voyvodic, James T; Johnson, Micah A; Camblin, C Christine

    2014-01-01

    Language production requires multiple stages of processing (e.g., semantic retrieval, lexical selection), each of which may involve distinct brain regions. Distractor words can be combined with picture naming to examine factors that influence language production. Phonologically-related distractors have been found to speed picture naming (facilitation), while slower response times and decreased accuracy (interference) generally occur when a distractor is categorically related to the target image. However, other types of semantically-related distractors have been reported to produce a facilitative effect (e.g., associative, part-whole). The different pattern of results for different types of semantically-related distractors raises the question about how the nature of the semantic relation influences the effect of the distractor. To explore the nature of these semantic effects further, we used functional MRI to examine the influence of four types of written distractors on brain activation during overt picture naming. Distractors began with the same sound, were categorically-related, part of the object to be named, or were unrelated to the picture. Phonologically-related trials elicited greater activation than both semantic conditions (categorically-related and part-whole) in left insula and bilateral parietal cortex, regions that have been attributed to phonological aspects of production and encoding, respectively. Semantic conditions elicited greater activation than phonological trials in left posterior MTG, a region that has been linked to concept retrieval and semantic integration. Overall, the two semantic conditions did not differ substantially in their functional activation which suggests a similarity in the semantic demands and lexical competition across these two conditions.

  14. How Situational Context Impacts Empathic Responses and Brain Activation Patterns

    Directory of Open Access Journals (Sweden)

    Yawei Cheng

    2017-09-01

    Full Text Available Clinical empathy, which is defined as the ability to understand the patient’s experience and feelings from the patient’s perspective, is acknowledged to be an important aspect of quality healthcare. However, how work experience modulates the empathic responses and brain activation patterns in medical professions remains elusive. This fMRI study recruited one hundred female nurses, who varied the length of work experience, and examined how their neural response, functional connectivity, and subjective evaluations of valence and arousal to perceiving another individual in physical pain are modulated by the situational context in which they occur (i.e., in a hospital or at home. Participants with longer hospital terms evaluated pain as less negative in valence and arousal when occurring in a hospital context, but not in a home context. Physical pain perceived in a hospital compared to a home context produced stronger activity in the right temporoparietal junction (rTPJ. The reverse comparison resulted in an increased activity in the insula and anterior midcingulate cortex (aMCC. Mediation analysis indicated that reduced personal accomplishment, a symptom of burnout, breaks down the mediation effect of the putamen on context-dependent valence ratings. Overall, the study demonstrates how situational contexts significantly influence individuals’ empathic processing, and that perceiving reward from patient care protects them from burnout.Highlights-Differences in behavior ratings and brain activations between medical practitioners perceiving others’ pain in a hospital and at home.-Situational contexts significantly influence individual’s empathic processing.-Perceiving rewards from patient care protects medical practitioners from burnout.-Empathy is a flexible phenomenon.

  15. New electroencephalogram (EEG) neuroimaging methods of analyzing brain activity applicable to the study of human sexual response.

    Science.gov (United States)

    Ortigue, Stephanie; Patel, Nisa; Bianchi-Demicheli, Francesco

    2009-07-01

    Electroencephalogram (EEG) combined with brain source localization algorithms is becoming a powerful tool in the neuroimaging study of human cerebral functions. The present article provides a tutorial on the various EEG methods currently used to study the human brain activity, notably during sexual response. Review of published literature on standard EEG waveform analyses and most recent electrical neuroimaging techniques (microstate approach and two methods of brain source localization). Retrospective overview of pertinent literature. Although the standard EEG waveform analyses enable millisecond time-resolution information about the human sexual responses in the brain, less is clear about their related spatial information. Nowadays, the improvement of EEG techniques and statistical approaches allows the visualization of the dynamics of the human sexual response with a higher spatiotemporal resolution. Here, we describe these enhanced techniques and summarize along with an overview of what we have learned from them in terms of chronoarchitecture of sexual response in the human brain. Finally, the speculation on how we may be able to use other enhanced approaches, such as independent component analysis, are also presented. EEG neuroimaging has already been proven as a strong worthwhile research tool. Combining this approach with standard EEG waveform analyses in sexual medicine may provide a better understanding of the neural activity underlying the human sexual response in both healthy and clinical populations.

  16. Protease-activated receptor-2 regulates trypsin expression in the brain and protects against seizures and epileptogenesis.

    Science.gov (United States)

    Lohman, Rink-Jan; O'Brien, Terence J; Cocks, Thomas M

    2008-04-01

    Protease-activated receptor-2 (PAR(2)), primarily involved in inflammation, is highly expressed in limbic regions of the brain such as the hippocampus. Although extracellular proteolysis is involved in normal and stress-related neuronal plasticity associated with learning, memory and inflammatory disease states, little is known about the role of PAR(2) and its physiological agonist, trypsin, in the brain. We show immunohistochemically that trypsin co-localises with tissue plasminogen activator within granular-like structures in PAR(2)-positive pyramidal neurons of the rat hippocampus. Central administration of the PAR(2) peptide agonist, SLIGRL, inhibited electrical amygdala kindling-induced epileptogenesis and abolished kindling-induced over-expression of trypsin in the hippocampus. SLIGRL similarly attenuated kindling when administered subcutaneously. Non-enzymatic activation of neuronal PAR(2) using SLIGRL may thus activate feedback mechanisms to inhibit the over-production of trypsin and possibly other proteases during brain insults and thereby attenuate pathogenesis. Prophylactic systemic administration of non-proteolytic PAR(2) agonists may therefore represent a novel approach to protect against epileptogenic brain insults.

  17. Activated brain mast cells contribute to postoperative cognitive dysfunction by evoking microglia activation and neuronal apoptosis.

    Science.gov (United States)

    Zhang, Xiang; Dong, Hongquan; Li, Nana; Zhang, Susu; Sun, Jie; Zhang, Shu; Qian, Yanning

    2016-05-31

    Neuroinflammation plays a key role in the occurrence and development of postoperative cognitive dysfunction (POCD). Microglia, the resident immune cells in the brain, has been increasingly recognized to contribute to neuroinflammation. Although brain mast cells (MCs) are the "first responder" in the brain injury rather than microglia, little is known about the functional aspects of MCs-microglia interactions. Male Sprague-Dawley (SD) rats were injected intracerebroventricular with MC stabilizer Cromolyn (100 μg/μl), MC stimulator C48/80 (1 μg/μl), or sterile saline 30 min before open tibial fracture surgery, and the levels of neuroinflammation and memory dysfunction were tested 1 and 3 days after surgery. In addition, the effect of activated MCs on microglia and neurons was determined in vitro. Tibial fracture surgery induced MCs degranulation, microglia activation, and inflammatory factors production, which initiated the acute brain inflammatory response and neuronal death and exhibited cognitive deficit. Site-directed preinjection of the "MCs stabilizer" disodium cromoglycate (Cromolyn) inhibited this effect, including decrease of inflammatory cytokines, reduced MCs degranulation, microglia activation, neuronal death, and improved cognitive function 24 h after the surgery. In vitro study, we found that the conditioned medium from lipopolysaccharide (LPS)-stimulated mast cells line (P815) could induce primary microglia activation through mitogen-activated protein kinase (MAPK) pathway signaling and subsequent production of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). In addition, the activated P815 could directly induce neuronal apoptosis and synapse injury with microglia independently. Cromolyn could inhibit P815 activation following improved microglia activation and neuronal loss. These results implicate that activated MCs could trigger microglia activation and neuronal damage, resulting in central nervous system (CNS) inflammation, and

  18. Changes in intestinal electrical activity during ischaemia correlate to ...

    African Journals Online (AJOL)

    The gastrointestinal tract possesses an omnipresent electrical slow wave called the basic electrical rhythm (BER). It has been shown that the frequency of the BER falls during intestinal ischaemia. The correlation between changes in the BER and pathology that occur during acute ischaemia are not completely understood.

  19. Ground electrical conductivity for medium wave activities over Nigeria

    African Journals Online (AJOL)

    Ground electrical properties remain a useful tool for most applications in engineering and communication, therefore, reliability and precision is highly required in their determination. Ground electrical conductivity as a function of signal frequency has been determined at Ilorin during the dry and the wet seasons. The study ...

  20. Hybrid brain-computer interface and functional electrical stimulation for sensorimotor training in participants with tetraplegia: a proof-of-concept study.

    Science.gov (United States)

    Vučković, Aleksandra; Wallace, Leslie; Allan, David B

    2015-01-01

    Impaired hand function decreases quality of life in persons with tetraplegia. We tested functional electrical stimulation (FES) controlled by a hybrid brain-computer interface (BCI) for improving hand function in participants with tetraplegia. Two participants with subacute tetraplegia (participant 1: C5 Brown-Sequard syndrome, participant 2: complete C5 lesion) took part in this proof-of-concept study. The goal was to determine whether the BCI system could drive the FES device by accurately classifying participants' intent (open or close the hand). Participants 1 and 2 received 10 sessions and 4 sessions of BCI-FES, respectively. A novel time-switch BCI strategy based on motor imagery was used to activate the FES. In one session, we tested a hybrid BCI-FES based on 2 spontaneously generated brain rhythms: a sensory-motor rhythm during motor imagery to activate a stimulator and occipital alpha rhythms to deactivate the stimulator. Participants received BCI-FES therapy 2 to 3 times a week in addition to conventional therapy. Imagery ability and muscle strength were measured before and after treatment. Visual feedback was associated with a 4-fold increase of brain response during motor imagery in both participants. For participant 1, classification accuracy (open/closed) for motor imagery-based BCI was 83.5% (left hand) and 83.8% (right hand); participant 2 had a classification accuracy of 83.8% for the right hand. Participant 1 had moderate improvement in muscle strength, while there was no change for participant 2. We demonstrated feasibility of BCI-FES, using 2 naturally generated brain rhythms. Studies on a larger number of participants are needed to separate the effects of BCI training from effects of conventional therapy.Video Abstract available. (see Video, Supplemental Digital Content 1, http://links.lww.com/JNPT/A84) for more insights from the authors.

  1. Fetal brain activity and hemodynamic response to a vibroacoustic stimulus.

    Science.gov (United States)

    Fulford, Jonathan; Vadeyar, Shantala H; Dodampahala, Sanani H; Ong, Stephen; Moore, Rachel J; Baker, Philip N; James, David K; Gowland, Penny

    2004-06-01

    Previous studies have demonstrated the practicality of using functional magnetic resonance imaging (fMRI) techniques to assess fetal brain activity. The purpose of this study was to compare the fetal hemodynamic response to that of the adult. Seventeen pregnant subjects, all of whom were at more than 36 weeks gestation were scanned while the fetus was exposed to a vibroacoustic stimulus. Thirteen adult subjects were scanned with an equivalent acoustic stimulus. Of the fetal subjects, two could not be analyzed due to technical problems, eight did not show significant activation, and seven showed significant activation. In all cases, activation was localized within the temporal region. Measures of fetal hemodynamic responses revealed an average time to peak (ttp) of 7.36 +/- 0.94 sec and an average percentage change of 2.67 +/- 0.93%. In contrast, activation was detected in 5 of 13 adults with an average ttp of 6.54 +/- 0.54 sec and an average percentage change of 1.02 +/- 0.40%. The measurement of changes in the fetal hemodynamic response may be important in assessing compromised pregnancies. Copyright 2004 Wiley-Liss, Inc.

  2. Brain-specific transcriptional regulator T-brain-1 controls brain wiring and neuronal activity in autism spectrum disorders

    Directory of Open Access Journals (Sweden)

    Tzyy-Nan eHuang

    2015-11-01

    Full Text Available T-brain-1 (TBR1 is a brain-specific T-box transcription factor. In 1995, Tbr1 was first identified from a subtractive hybridization that compared mouse embryonic and adult telencephalons. Previous studies of Tbr1–/– mice have indicated critical roles for TBR1 in the development of the cerebral cortex, amygdala and olfactory bulb. Neuronal migration and axonal projection are two important developmental features controlled by TBR1. Recently, recurrent de novo disruptive mutations in the TBR1 gene have been found in patients with autism spectrum disorders (ASDs. Human genetic studies have identified TBR1 as a high-confidence risk factor for ASDs. Because only one allele of the TBR1 gene is mutated in these patients, Tbr1+/– mice serve as a good genetic mouse model to explore the mechanism by which de novo TBR1 mutation leads to ASDs. Although neuronal migration and axonal projection defects of cerebral cortex are the most prominent phenotypes in Tbr1–/– mice, these features are not found in Tbr1+/– mice. Instead, inter- and intra-amygdalar axonal projections and NMDAR expression and activity in amygdala are particularly susceptible to Tbr1 haploinsufficiency. The studies indicated that both abnormal brain wiring (abnormal amygdalar connections and excitation/inhibition imbalance (NMDAR hypoactivity, two prominent models for ASD etiology, are present in Tbr1+/– mice. Moreover, calcium/calmodulin-dependent serine protein kinase (CASK was found to interact with TBR1. The CASK-TBR1 complex had been shown to directly bind the promoter of the Grin2b gene, which is also known as Nmdar2b, and upregulate Grin2b expression. This molecular function of TBR1 provides an explanation for NMDAR hypoactivity in Tbr1+/– mice. In addition to Grin2b, cell adhesion molecules-including Ntng1, Cdh8 and Cntn2-are also regulated by TBR1 to control axonal projections of amygdala. Taken together, the studies of Tbr1 provide an integrated picture of ASD

  3. Physical activity and the brain: a review of this dynamic, bi-directional relationship.

    Science.gov (United States)

    Loprinzi, Paul D; Herod, Skyla M; Cardinal, Bradley J; Noakes, Timothy D

    2013-11-20

    The brain plays a major role in regulating physical activity behavior and exercise performance. Regular physical activity may also play a key role in the prevention and treatment of various neurological conditions, such as Parkinson's disease, Alzheimer's disease, depression, and cognitive function. This implies that not only does the brain (or the nervous system) regulate aspects of physical activity, but also that physical activity may potentially influence brain-related function and outcomes. This review details this bi-directional relationship and addresses its implications for improving physical activity, exercise performance, and brain-related function and outcomes. © 2013 Elsevier B.V. All rights reserved.

  4. In-vivo measurements of human brain tissue conductivity using focal electrical current injection through intracerebral multicontact electrodes.

    Science.gov (United States)

    Koessler, Laurent; Colnat-Coulbois, Sophie; Cecchin, Thierry; Hofmanis, Janis; Dmochowski, Jacek P; Norcia, Anthony M; Maillard, Louis G

    2017-02-01

    In-vivo measurements of human brain tissue conductivity at body temperature were conducted using focal electrical currents injected through intracerebral multicontact electrodes. A total of 1,421 measurements in 15 epileptic patients (age: 28 ± 10) using a radiofrequency generator (50 kHz current injection) were analyzed. Each contact pair was classified as being from healthy (gray matter, n = 696; white matter, n = 530) or pathological (epileptogenic zone, n = 195) tissue using neuroimaging analysis of the local tissue environment and intracerebral EEG recordings. Brain tissue conductivities were obtained using numerical simulations based on conductivity estimates that accounted for the current flow in the local brain volume around the contact pairs (a cube with a side length of 13 mm). Conductivity values were 0.26 S/m for gray matter and 0.17 S/m for white matter. Healthy gray and white matter had statistically different median impedances (P Brain Mapp 38:974-986, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  5. A Permutation Disalignment Index-Based Complex Network Approach to Evaluate Longitudinal Changes in Brain-Electrical Connectivity

    Directory of Open Access Journals (Sweden)

    Nadia Mammone

    2017-10-01

    Full Text Available In the study of neurological disorders, Electroencephalographic (EEG signal processing can provide valuable information because abnormalities in the interaction between neuron circuits may reflect on macroscopic abnormalities in the electrical potentials that can be detected on the scalp. A Mild Cognitive Impairment (MCI condition, when caused by a disorder degenerating into dementia, affects the brain connectivity. Motivated by the promising results achieved through the recently developed descriptor of coupling strength between EEG signals, the Permutation Disalignment Index (PDI, the present paper introduces a novel PDI-based complex network model to evaluate the longitudinal variations in brain-electrical connectivity. A group of 33 amnestic MCI subjects was enrolled and followed-up with over four months. The results were compared to MoCA (Montreal Cognitive Assessment tests, which scores the cognitive abilities of the patient. A significant negative correlation could be observed between MoCA variation and the characteristic path length ( λ variation ( r = - 0 . 56 , p = 0 . 0006 , whereas a significant positive correlation could be observed between MoCA variation and the variation of clustering coefficient (CC, r = 0 . 58 , p = 0 . 0004 , global efficiency (GE, r = 0 . 57 , p = 0 . 0005 and small worldness (SW, r = 0 . 57 , p = 0 . 0005 . Cognitive decline thus seems to reflect an underlying cortical “disconnection” phenomenon: worsened subjects indeed showed an increased λ and decreased CC, GE and SW. The PDI-based connectivity model, proposed in the present work, could be a novel tool for the objective quantification of longitudinal brain-electrical connectivity changes in MCI subjects.

  6. Reaction time variability and related brain activity in methamphetamine psychosis.

    Science.gov (United States)

    Fassbender, Catherine; Lesh, Tyler A; Ursu, Stefan; Salo, Ruth

    2015-03-01

    This study investigated the dynamics of cognitive control instability in methamphetamine (MA) abuse, as well its relationship to substance-induced psychiatric symptoms and drug use patterns. We used an ex-Gaussian reaction time (RT) distribution to examine intraindividual variability (IIV) and excessively long RTs (tau) in an individual's RT on a Stroop task in 30 currently drug-abstinent (3 months to 2 years) MA abusers compared with 27 nonsubstance-abusing control subjects. All subjects underwent functional magnetic resonance imaging while performing the Stroop task, which allowed us to measure the relationship between IIV and tau to functional brain activity. Elevated IIV in the MA compared with the control group did not reach significance; however, when the MA group was divided into those subjects who had experienced MA-induced psychosis (MAP+) (n = 19) and those who had not (n = 11), the MAP+ group had higher average IIV compared with the other groups (p < .03). In addition, although control subjects displayed a relationship between IIV and conflict-related brain activity in bilateral prefrontal cortex such that increased IIV was associated with increased activity, the MAP+ group displayed this relationship in right prefrontal cortex only, perhaps reflecting elevated vigilance in the MAP+ group. Greater IIV did not correlate with severity of use or months MA abstinent. No group differences emerged in tau values. These results suggest increased cognitive instability in those MA-dependent subjects who had experienced MA-induced psychosis. Copyright © 2015 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

  7. Human Brain Activity Related to the Tactile Perception of Stickiness

    Science.gov (United States)

    Yeon, Jiwon; Kim, Junsuk; Ryu, Jaekyun; Park, Jang-Yeon; Chung, Soon-Cheol; Kim, Sung-Phil

    2017-01-01

    While the perception of stickiness serves as one of the fundamental dimensions for tactile sensation, little has been elucidated about the stickiness sensation and its neural correlates. The present study investigated how the human brain responds to perceived tactile sticky stimuli using functional magnetic resonance imaging (fMRI). To evoke tactile perception of stickiness with multiple intensities, we generated silicone stimuli with varying catalyst ratios. Also, an acrylic sham stimulus was prepared to present a condition with no sticky sensation. From the two psychophysics experiments–the methods of constant stimuli and the magnitude estimation—we could classify the silicone stimuli into two groups according to whether a sticky perception was evoked: the Supra-threshold group that evoked sticky perception and the Infra-threshold group that did not. In the Supra-threshold vs. Sham contrast analysis of the fMRI data using the general linear model (GLM), the contralateral primary somatosensory area (S1) and ipsilateral dorsolateral prefrontal cortex (DLPFC) showed significant activations in subjects, whereas no significant result was found in the Infra-threshold vs. Sham contrast. This result indicates that the perception of stickiness not only activates the somatosensory cortex, but also possibly induces higher cognitive processes. Also, the Supra- vs. Infra-threshold contrast analysis revealed significant activations in several subcortical regions, including the pallidum, putamen, caudate and thalamus, as well as in another region spanning the insula and temporal cortices. These brain regions, previously known to be related to tactile discrimination, may subserve the discrimination of different intensities of tactile stickiness. The present study unveils the human neural correlates of the tactile perception of stickiness and may contribute to broadening the understanding of neural mechanisms associated with tactile perception. PMID:28163677

  8. Inhibition and recovery of continuous electric field application on the activity of anammox biomass.

    Science.gov (United States)

    Qiao, Sen; Yin, Xin; Zhou, Jiti; Furukawa, Kenji

    2014-07-01

    In this study, the effects of electric field on the activity of anammox biomass were investigated. In batch mode, experimental results demonstrated that the nitrogen removal rate enhanced by 25.6 % compared with the control experiment at the electric field of 2 V/cm with application time of 20 min. However, continuous application (24 h) of electric field impacted a mal-effect on anammox biomass during the intensity between 1 and 4 V/cm. After the electric field was removed, the activity of anammox biomass could recover within 2 weeks. This implied that the mal-effect of electric field on anammox biomass was reversible. The decrease of heme c contents and crude enzyme activity demonstrated to be the main reason for the depress of the anammox biomass activity. Transmission electron microscope observation also proved the morphological change of anammox biomass under electric field.

  9. Brain activation by music in patients in a vegetative or minimally conscious state following diffuse brain injury.

    Science.gov (United States)

    Okumura, Yuka; Asano, Yoshitaka; Takenaka, Shunsuke; Fukuyama, Seisuke; Yonezawa, Shingo; Kasuya, Yukinori; Shinoda, Jun

    2014-01-01

    The aim of this study was to objectively evaluate the brain activity potential of patients with impaired consciousness in a chronic stage of diffuse brain injury (DBI) using functional MRI (fMRI) following music stimulation (MS). Two patients in a minimally conscious state (MCS) and five patients in a vegetative state (VS) due to severe DBI were enrolled along with 21 healthy adults. This study examined the brain regions activated by music and assessed topographical differences of the MS-activated brain among healthy adults and these patients. MS was shown to activate the bilateral superior temporal gyri (STG) of both healthy adults and patients in an MCS. In four of five patients in a VS, however, no significant activation in STG could be induced by the same MS. The remaining patient in a VS displayed the same MS-induced brain activation in STG as healthy adults and patients in an MCS and this patient's status also improved to an MCS 4 months after the study. The presence of STG activation by MS may predict a possible improvement of patients in a VS to MCS and fMRI employing MS may be a useful modality to objectively evaluate consciousness in these patients.

  10. Tasting calories differentially affects brain activation during hunger and satiety.

    Science.gov (United States)

    van Rijn, Inge; de Graaf, Cees; Smeets, Paul A M

    2015-02-15

    An important function of eating is ingesting energy. Our objectives were to assess whether oral exposure to caloric and non-caloric stimuli elicits discriminable responses in the brain and to determine in how far these responses are modulated by hunger state and sweetness. Thirty women tasted three stimuli in two motivational states (hunger and satiety) while their brain responses were measured using functional magnetic resonance imaging in a randomized crossover design. Stimuli were solutions of sucralose (sweet, no energy), maltodextrin (non-sweet, energy) and sucralose+maltodextrin (sweet, energy). We found no main effect of energy content and no interaction between energy content and sweetness. However, there was an interaction between hunger state and energy content in the median cingulate (bilaterally), ventrolateral prefrontal cortex, anterior insula and thalamus. This indicates that the anterior insula and thalamus, areas in which hunger state and taste of a stimulus are integrated, also integrate hunger state with caloric content of a taste stimulus. Furthermore, in the median cingulate and ventrolateral prefrontal cortex, tasting energy resulted in more activation during satiety compared to hunger. This finding indicates that these areas, which are known to be involved in processes that require approach and avoidance, are also involved in guiding ingestive behavior. In conclusion, our results suggest that energy sensing is a hunger state dependent process, in which the median cingulate, ventrolateral prefrontal cortex, anterior insula and thalamus play a central role by integrating hunger state with stimulus relevance. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Assessment of Electrically Evoked Auditory Brain Stem Response of 30 Implanted Patients With Nucleus Multichannel Cochlear Implant

    Directory of Open Access Journals (Sweden)

    Dr. Soqrat Faghihzadeh

    2001-05-01

    Full Text Available Methods and Materials: Investigation of electrically evoked auditory brain stem response (EABR is a new issue, especially in implanted patients. Experiments were performed in C.I Center of Iranian Institute for Science and research expansion,1996 on 30 implanted patients with 22 spectra and MSP cochlear implant system and 30 normal subjects with the range of 3-33 years. Findings: I- EABR was obtained in the implanted patients. 2- Absolute latency of EABR waves is 1-1.5 ms shorter than ABR waves ‘P<0.05. 3-Absolute latency of wave V decreases as a function of electric stimulus magnitude (P<0.05. 4- No significant difference was observed in IPL Ill-V between ABR and EABR.

  12. Activity-dependent, stress-responsive BDNF signaling and the quest for optimal brain health and resilience throughout the lifespan.

    Science.gov (United States)

    Rothman, S M; Mattson, M P

    2013-06-03

    During development of the nervous system, the formation of connections (synapses) between neurons is dependent upon electrical activity in those neurons, and neurotrophic factors produced by target cells play a pivotal role in such activity-dependent sculpting of the neural networks. A similar interplay between neurotransmitter and neurotrophic factor signaling pathways mediates adaptive responses of neural networks to environmental demands in adult mammals, with the excitatory neurotransmitter glutamate and brain-derived neurotrophic factor (BDNF) being particularly prominent regulators of synaptic plasticity throughout the central nervous system. Optimal brain health throughout the lifespan is promoted by intermittent challenges such as exercise, cognitive stimulation and dietary energy restriction, that subject neurons to activity-related metabolic stress. At the molecular level, such challenges to neurons result in the production of proteins involved in neurogenesis, learning and memory and neuronal survival; examples include proteins that regulate mitochondrial biogenesis, protein quality control, and resistance of cells to oxidative, metabolic and proteotoxic stress. BDNF signaling mediates up-regulation of several such proteins including the protein chaperone GRP-78, antioxidant enzymes, the cell survival protein Bcl-2, and the DNA repair enzyme APE1. Insufficient exposure to such challenges, genetic factors may conspire to impair BDNF production and/or signaling resulting in the vulnerability of the brain to injury and neurodegenerative disorders including Alzheimer's, Parkinson's and Huntington's diseases. Further, BDNF signaling is negatively regulated by glucocorticoids. Glucocorticoids impair synaptic plasticity in the brain by negatively regulating spine density, neurogenesis and long-term potentiation, effects that are potentially linked to glucocorticoid regulation of BDNF. Findings suggest that BDNF signaling in specific brain regions mediates some

  13. Guiding transcranial brain stimulation by EEG/MEG to interact with ongoing brain activity and associated functions: A position paper.

    Science.gov (United States)

    Thut, Gregor; Bergmann, Til Ole; Fröhlich, Flavio; Soekadar, Surjo R; Brittain, John-Stuart; Valero-Cabré, Antoni; Sack, Alexander T; Miniussi, Carlo; Antal, Andrea; Siebner, Hartwig Roman; Ziemann, Ulf; Herrmann, Christoph S

    2017-05-01

    Non-invasive transcranial brain stimulation (NTBS) techniques have a wide range of applications but also suffer from a number of limitations mainly related to poor specificity of intervention and variable effect size. These limitations motivated recent efforts to focus on the temporal dimension of NTBS with respect to the ongoing brain activity. Temporal patterns of ongoing neuronal activity, in particular brain oscillations and their fluctuations, can be traced with electro- or magnetoencephalography (EEG/MEG), to guide the timing as well as the stimulation settings of NTBS. These novel, online and offline EEG/MEG-guided NTBS-approaches are tailored to specifically interact with the underlying brain activity. Online EEG/MEG has been used to guide the timing of NTBS (i.e., when to stimulate): by taking into account instantaneous phase or power of oscillatory brain activity, NTBS can be aligned to fluctuations in excitability states. Moreover, offline EEG/MEG recordings prior to interventions can inform researchers and clinicians how to stimulate: by frequency-tuning NTBS to the oscillation of interest, intrinsic brain oscillations can be up- or down-regulated. In this paper, we provide an overview of existing approaches and ideas of EEG/MEG-guided interventions, and their promises and caveats. We point out potential future lines of research to address challenges. Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

  14. Neurofeedback tunes scale-free dynamics in spontaneous brain activity

    NARCIS (Netherlands)

    Ros, T.; Frewen, P.A.; Thé berge, J.; Michela, A.; Kluetsch, R.C.; Mü ller, A.; Candrian, G.; Jetly, R.; Vuilleumier, P.; Lanius, R.

    2017-01-01

    Brain oscillations exhibit long-range temporal correlations (LRTCs), which reflect the regularity of their fluctuations: low values representing more random (decorrelated) while high values more persistent (correlated) dynamics. LRTCs constitute supporting evidence that the brain operates near

  15. Multi-Person Brain Activity Recognition via Comprehensive EEG Signal Analysis

    OpenAIRE

    Zhang, Xiang; Yao, Lina; Zhang, Dalin; Wang, Xianzhi; Sheng, Quan Z.; Gu, Tao

    2017-01-01

    An electroencephalography (EEG) based brain activity recognition is a fundamental field of study for a number of significant applications such as intention prediction, appliance control, and neurological disease diagnosis in smart home and smart healthcare domains. Existing techniques mostly focus on binary brain activity recognition for a single person, which limits their deployment in wider and complex practical scenarios. Therefore, multi-person and multi-class brain activity recognition h...

  16. Brain activation in response to bladder filling in healthy adults: An activation likelihood estimation meta-analysis of neuroimaging studies.

    Science.gov (United States)

    Arya, Nisha G; Weissbart, Steven J; Xu, Sihua; Rao, Hengyi

    2017-04-01

    Recent studies have used different neuroimaging techniques and identified various brain regions that are activated during bladder filling. However, there is a lack of consensus regarding which of these brain regions regulate the process of urine storage. The aim of this meta-analysis is to identify brain regions that are commonly activated during bladder filling in healthy adults across different studies. PubMed was searched for neuroimaging studies investigating the effects of bladder filling on regional brain activation. Studies were excluded if they did not report brain activation differences from whole-brain group analysis by comparing the state of bladder filling with the state of bladder rest. The current version of the activation likelihood estimation (ALE) approach was used for meta-analysis. We identified 14 neuroimaging studies examining brain activation in response to experimental bladder filling in 181 healthy subjects, which reported 89 foci for ALE analysis. The meta-analysis revealed significant activation in multiple brain regions including thalamus (bilaterally), right insula, cerebellum, and brainstem (bilaterally). Several key brain regions involved in sensory processing are commonly activated during bladder filling in healthy adults across different studies. Neurourol. Urodynam. 36:960-965, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  17. Task Context Influences Brain Activation during Music Listening

    Directory of Open Access Journals (Sweden)

    Andjela Markovic

    2017-06-01

    Full Text Available In this paper, we examined brain activation in subjects during two music listening conditions: listening while simultaneously rating the musical piece being played [Listening and Rating (LR] and listening to the musical pieces unconstrained [Listening (L]. Using these two conditions, we tested whether the sequence in which the two conditions were fulfilled influenced the brain activation observable during the L condition (LR → L or L → LR. We recorded high-density EEG during the playing of four well-known positively experienced soundtracks in two subject groups. One group started with the L condition and continued with the LR condition (L → LR; the second group performed this experiment in reversed order (LR → L. We computed from the recorded EEG the power for different frequency bands (theta, lower alpha, upper alpha, lower beta, and upper beta. Statistical analysis revealed that the power in all examined frequency bands increased during the L condition but only when the subjects had not had previous experience with the LR condition (i.e., L → LR. For the subjects who began with the LR condition, there were no power increases during the L condition. Thus, the previous experience with the LR condition prevented subjects from developing the particular mental state associated with the typical power increase in all frequency bands. The subjects without previous experience of the LR condition listened to the musical pieces in an unconstrained and undisturbed manner and showed a general power increase in all frequency bands. We interpret the fact that unconstrained music listening was associated with increased power in all examined frequency bands as a neural indicator of a mental state that can best be described as a mind-wandering state during which the subjects are “drawn into” the music.

  18. Task Context Influences Brain Activation during Music Listening.

    Science.gov (United States)

    Markovic, Andjela; Kühnis, Jürg; Jäncke, Lutz

    2017-01-01

    In this paper, we examined brain activation in subjects during two music listening conditions: listening while simultaneously rating the musical piece being played [Listening and Rating (LR)] and listening to the musical pieces unconstrained [Listening (L)]. Using these two conditions, we tested whether the sequence in which the two conditions were fulfilled influenced the brain activation observable during the L condition (LR → L or L → LR). We recorded high-density EEG during the playing of four well-known positively experienced soundtracks in two subject groups. One group started with the L condition and continued with the LR condition (L → LR); the second group performed this experiment in reversed order (LR → L). We computed from the recorded EEG the power for different frequency bands (theta, lower alpha, upper alpha, lower beta, and upper beta). Statistical analysis revealed that the power in all examined frequency bands increased during the L condition but only when the subjects had not had previous experience with the LR condition (i.e., L → LR). For the subjects who began with the LR condition, there were no power increases during the L condition. Thus, the previous experience with the LR condition prevented subjects from developing the particular mental state associated with the typical power increase in all frequency bands. The subjects without previous experience of the LR condition listened to the musical pieces in an unconstrained and undisturbed manner and showed a general power increase in all frequency bands. We interpret the fact that unconstrained music listening was associated with increased power in all examined frequency bands as a neural indicator of a mental state that can best be described as a mind-wandering state during which the subjects are "drawn into" the music.

  19. Is Brain Activity during Action Observation Modulated by the Perceived Fairness of the Actor?

    NARCIS (Netherlands)

    Etzel, Joset A.; Valchev, Nikola; Gazzola, Valeria; Keysers, Christian

    2016-01-01

    Perceiving other people's actions triggers activity in premotor and parietal areas, brain areas also involved in executing and sensing our own actions. Paralleling this phenomenon, observing emotional states (including pain) in others is associated with activity in the same brain areas as activated

  20. Contribution of regional brain melanocortin receptor subtypes to elevated activity energy expenditure in lean, active rats.

    Science.gov (United States)

    Shukla, C; Koch, L G; Britton, S L; Cai, M; Hruby, V J; Bednarek, M; Novak, C M

    2015-12-03

    Physical activity and non-exercise activity thermogenesis (NEAT) are crucial factors accounting for individual differences in body weight, interacting with genetic predisposition. In the brain, a number of neuroendocrine intermediates regulate food intake and energy expenditure (EE); this includes the brain melanocortin (MC) system, consisting of MC peptides as well as their receptors (MCR). MC3R and MC4R have emerged as critical modulators of EE and food intake. To determine how variance in MC signaling may underlie individual differences in physical activity levels, we examined behavioral response to MC receptor agonists and antagonists in rats that show high and low levels of physical activity and NEAT, that is, high- and low-capacity runners (HCR, LCR), developed by artificial selection for differential intrinsic aerobic running capacity. Focusing on the hypothalamus, we identified brain region-specific elevations in expression of MCR 3, 4, and also MC5R, in the highly active, lean HCR relative to the less active and obesity-prone LCR. Further, the differences in activity and associated EE as a result of MCR activation or suppression using specific agonists and antagonists were similarly region-specific and directly corresponded to the differential MCR expression patterns. The agonists and antagonists investigated here did not significantly impact food intake at the doses used, suggesting that the differential pattern of receptor expression may by more meaningful to physical activity than to other aspects of energy balance regulation. Thus, MCR-mediated physical activity may be a key neural mechanism in distinguishing the lean phenotype and a target for enhancing physical activity and NEAT. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

  1. Effect of acute hyperoxia during exercise on quadriceps electrical activity in active COPD patients.

    Science.gov (United States)

    Gosselin, N; Durand, F; Poulain, M; Lambert, K; Ceugniet, F; Préfaut, C; Varray, A

    2004-07-01

    This study investigated whether acute hyperoxia improves electrical muscle activity in active chronic obstructive pulmonary disease (COPD) patients with mild hypoxemia (rest PaO(2) = 9.1 +/- 0.4 kPa). Two identical incremental exercise tests were performed by nine patients while breathing either air or 30% oxygen. Pulmonary gas exchanges, venous concentrations of lactate and pyruvate, and the electromyographic signal of the quadriceps muscle (vastus lateralis and vastus medialis) were sampled each minute. Peak working capacity increased significantly in hyperoxia (94.4 +/- 5.2W) compared with normoxia (85.4 +/- 5.8W, P exercise and for a given work load, oxygen uptake was increased (P exercise compared with room air. Although median frequency values did not differ between conditions, the median frequency was significantly decreased for higher exercise intensity in hyperoxic condition. These modifications reflected better aerobic metabolism, later emergence of muscle fatigue, and greater muscle excitability and activation for the same level of exercise under hyperoxic condition. These data suggest that the acute addition of oxygen in active COPD patients improves their muscle electrical activity during dynamic exercise. Hypoxemia-induced skeletal muscle dysfunction most probably acts through mechanisms based on oxygen availability.

  2. Building an index of activity of inhabitants from their activity on the residential electrical power line.

    Science.gov (United States)

    Noury, Norbert; Berenguer, Marc; Teyssier, Henri; Bouzid, Marie-Jeanne; Giordani, Michel

    2011-09-01

    In the framework of context awareness within the home, our team is currently assessing the unobtrusive detection of inhabitants' activity through the monitoring of their use and consumption of electricity. The objective is to develop a system for the remote monitoring of large populations of elderly people living independently at home. To be readily deployable on the field, such a system must be minimally intrusive both for the home environment and for the field professionals (paramedics and social workers) visiting the patients at home. We carried out two successive field experiments to evaluate and to improve our system designed to deliver a single index of daily activity. The first experiment involved 13 elderly persons over a nine-month period (84,240 h data recorded) and the second one 12 elderly over six months (51,840 h). We evaluated both the relevance of the index and the acceptability of the system as a whole. We discovered that electrical activity is a kind of unique "signature" of each person's activity. Moreover, this profile provides unexpected information on the health status of the subject. We confirmed that the system was unobtrusive and well accepted both by the subjects and by the professionals involved. Our unique index of activity, and its trend over time, can provide timely information to the professionals on the patient.

  3. Brain activity accompanying perception of implied motion in abstract paintings.

    Science.gov (United States)

    Kim, Chai-Youn; Blake, Randolph

    2007-01-01

    Early 20th century artists including Duchamp and Balla tried to portray moving objects on a static canvas by superimposing objects in successive portrayals of an action. We investigated whether implied motion in those paintings is associated with activation of motion-sensitive area MT+. In Experiment 1, we found that observers rated these kinds of paintings higher in portraying motion than they did other abstract paintings in which motion is not intended. We also found that observers who had previously experienced abstract paintings with implied motion tended to give higher motion ratings to that class of paintings. In Experiment 2, we used functional magnetic resonance imaging (fMRI) to measure brain activity of observers while viewing abstract paintings receiving the highest and the lowest motion rating scores in Experiment 1. We found MT+, but not primary visual cortex (V1), showed greater BOLD responses to abstract paintings with implied motion than to abstract paintings with little motion impression, but only in observers with prior experience viewing those kinds of paintings. These results imply that the neural machinery ordinarily engaged during perception of real visual motion is activated when people view paintings explicitly designed to convey a sense of visual motion. Experience, however, is necessary to achieve this sense of motion.

  4. Own-gender imitation activates the brain's reward circuitry.

    Science.gov (United States)

    Losin, Elizabeth A Reynolds; Iacoboni, Macro; Martin, Alia; Dapretto, Mirella

    2012-10-01

    Imitation is an important component of human social learning throughout life. Theoretical models and empirical data from anthropology and psychology suggest that people tend to imitate self-similar individuals, and that such imitation biases increase the adaptive value (e.g., self-relevance) of learned information. It is unclear, however, what neural mechanisms underlie people's tendency to imitate those similar to themselves. We focused on the own-gender imitation bias, a pervasive bias thought to be important for gender identity development. While undergoing fMRI, participants imitated own- and other-gender actors performing novel, meaningless hand signs; as control conditions, they also simply observed such actions and viewed still portraits of the same actors. Only the ventral and dorsal striatum, orbitofrontal cortex and amygdala were more active when imitating own- compared to other-gender individuals. A Bayesian analysis of the BrainMap neuroimaging database demonstrated that the striatal region preferentially activated by own-gender imitation is selectively activated by classical reward tasks in the literature. Taken together, these findings reveal a neurobiological mechanism associated with the own-gender imitation bias and demonstrate a novel role of reward-processing neural structures in social behavior.

  5. Analysis of energy restriction and physical activity on brain function: the role of ketone body and brain-derived neurotrophic factor

    OpenAIRE

    Park, Chan Ho; Kwak, Yi-Sub

    2017-01-01

    Brain development is a complex process, and stimuli during this development period may modulate the functional maturation of the brain. It has been shown that environmental stimuli, such as physical activity habits, have a beneficial effect on brain development. Endurance exercise and prolonged fasting state are known to improve brain function including cognition. The exact mechanisms of exercise improving brain function are still unknown. However, it can be considered that energy restriction...

  6. Wnt activation of immortalized brain endothelial cells as a tool for generating a standardized model of the blood brain barrier in vitro.

    Directory of Open Access Journals (Sweden)

    Roberta Paolinelli

    Full Text Available Reproducing the characteristics and the functional responses of the blood-brain barrier (BBB in vitro represents an important task for the research community, and would be a critical biotechnological breakthrough. Pharmaceutical and biotechnology industries provide strong demand for inexpensive and easy-to-handle in vitro BBB models to screen novel drug candidates. Recently, it was shown that canonical Wnt signaling is responsible for the induction of the BBB properties in the neonatal brain microvasculature in vivo. In the present study, following on from earlier observations, we have developed a novel model of the BBB in vitro that may be suitable for large scale screening assays. This model is based on immortalized endothelial cell lines derived from murine and human brain, with no need for co-culture with astrocytes. To maintain the BBB endothelial cell properties, the cell lines are cultured in the presence of Wnt3a or drugs that stabilize β-catenin, or they are infected with a transcriptionally active form of β-catenin. Upon these treatments, the cell lines maintain expression of BBB-specific markers, which results in elevated transendothelial electrical resistance and reduced cell permeability. Importantly, these properties are retained for several passages in culture, and they can be reproduced and maintained in different laboratories over time. We conclude that the brain-derived endothelial cell lines that we have investigated gain their specialized characteristics upon activation of the canonical Wnt pathway. This model may be thus suitable to test the BBB permeability to chemicals or large molecular weight proteins, transmigration of inflammatory cells, treatments with cytokines, and genetic manipulation.

  7. Electric Field-aided Selective Activation for Indium-Gallium-Zinc-Oxide Thin Film Transistors.

    Science.gov (United States)

    Lee, Heesoo; Chang, Ki Soo; Tak, Young Jun; Jung, Tae Soo; Park, Jeong Woo; Kim, Won-Gi; Chung, Jusung; Jeong, Chan Bae; Kim, Hyun Jae

    2016-10-11

    A new technique is proposed for the activation of low temperature amorphous InGaZnO thin film transistor (a-IGZO TFT) backplanes through application of a bias voltage and annealing at 130 °C simultaneously. In this 'electrical activation', the effects of annealing under bias are selectively focused in the channel region. Therefore, electrical activation can be an effective method for lower backplane processing temperatures from 280 °C to 130 °C. Devices fabricated with this method exhibit equivalent electrical properties to those of conventionally-fabricated samples. These results are analyzed electrically and thermodynamically using infrared microthermography. Various bias voltages are applied to the gate, source, and drain electrodes while samples are annealed at 130 °C for 1 hour. Without conventional high temperature annealing or electrical activation, current-voltage curves do not show transfer characteristics. However, electrically activated a-IGZO TFTs show superior electrical characteristics, comparable to the reference TFTs annealed at 280 °C for 1 hour. This effect is a result of the lower activation energy, and efficient transfer of electrical and thermal energy to a-IGZO TFTs. With this approach, superior low-temperature a-IGZO TFTs are fabricated successfully.

  8. New Perspectives on Spontaneous Brain Activity: Dynamic Networks and Energy Matter.

    Science.gov (United States)

    Tozzi, Arturo; Zare, Marzieh; Benasich, April A

    2016-01-01

    Spontaneous brain activity has received increasing attention as demonstrated by the exponential rise in the number of published article on this topic over the last 30 years. Such "intrinsic" brain activity, generated in the absence of an explicit task, is frequently associated with resting-state or default-mode networks (DMN)s. The focus on characterizing spontaneous brain activity promises to shed new light on questions concerning the structural and functional architecture of the brain and how they are related to "mind". However, many critical questions have yet to be addressed. In this review, we focus on a scarcely explored area, specifically the energetic requirements and constraints of spontaneous activity, taking into account both thermodynamical and informational perspectives. We argue that the "classical" definitions of spontaneous activity do not take into account an important feature, that is, the critical thermodynamic energetic differences between spontaneous and evoked brain activity. Spontaneous brain activity is associated with slower oscillations compared with evoked, task-related activity, hence it exhibits lower levels of enthalpy and "free-energy" (i.e., the energy that can be converted to do work), thus supporting noteworthy thermodynamic energetic differences between spontaneous and evoked brain activity. Increased spike frequency during evoked activity has a significant metabolic cost, consequently, brain functions traditionally associated with spontaneous activity, such as mind wandering, require less energy that other nervous activities. We also review recent empirical observations in neuroscience, in order to capture how spontaneous brain dynamics and mental function can be embedded in a non-linear dynamical framework, which considers nervous activity in terms of phase spaces, particle trajectories, random walks, attractors and/or paths at the edge of the chaos. This takes us from the thermodynamic free-energy, to the realm of "variational

  9. New Perspectives on Spontaneous Brain Activity: Dynamic Networks and Energy Matter

    Science.gov (United States)

    Tozzi, Arturo; Zare, Marzieh; Benasich, April A.

    2016-01-01

    Spontaneous brain activity has received increasing attention as demonstrated by the exponential rise in the number of published article on this topic over the last 30 years. Such “intrinsic” brain activity, generated in the absence of an explicit task, is frequently associated with resting-state or default-mode networks (DMN)s. The focus on characterizing spontaneous brain activity promises to shed new light on questions concerning the structural and functional architecture of the brain and how they are related to “mind”. However, many critical questions have yet to be addressed. In this review, we focus on a scarcely explored area, specifically the energetic requirements and constraints of spontaneous activity, taking into account both thermodynamical and informational perspectives. We argue that the “classical” definitions of spontaneous activity do not take into account an important feature, that is, the critical thermodynamic energetic differences between spontaneous and evoked brain activity. Spontaneous brain activity is associated with slower oscillations compared with evoked, task-related activity, hence it exhibits lower levels of enthalpy and “free-energy” (i.e., the energy that can be converted to do work), thus supporting noteworthy thermodynamic energetic differences between spontaneous and evoked brain activity. Increased spike frequency during evoked activity has a significant metabolic cost, consequently, brain functions traditionally associated with spontaneous activity, such as mind wandering, require less energy that other nervous activities. We also review recent empirical observations in neuroscience, in order to capture how spontaneous brain dynamics and mental function can be embedded in a non-linear dynamical framework, which considers nervous activity in terms of phase spaces, particle trajectories, random walks, attractors and/or paths at the edge of the chaos. This takes us from the thermodynamic free-energy, to the realm

  10. Mapping social behavior-induced brain activation at cellular resolution in the mouse

    Science.gov (United States)

    Kim, Yongsoo; Venkataraju, Kannan Umadevi; Pradhan, Kith; Mende, Carolin; Taranda, Julian; Turaga, Srinivas C.; Arganda-Carreras, Ignacio; Ng, Lydia; Hawrylycz, Michael J.; Rockland, Kathleen; Seung, H. Sebastian; Osten, Pavel

    2014-01-01

    Understanding how brain activation mediates behaviors is a central goal of systems neuroscience. Here we apply an automated method for mapping brain activation in the mouse in order to probe how sex-specific social behaviors are represented in the male brain. Our method uses the immediate early gene c-fos, a marker of neuronal activation, visualized by serial two-photon tomography: the c-fos-GFP-positive neurons are computationally detected, their distribution is registered to a reference brain and a brain atlas, and their numbers are analyzed by statistical tests. Our results reveal distinct and shared female and male interaction-evoked patterns of male brain activation representing sex discrimination and social recognition. We also identify brain regions whose degree of activity correlates to specific features of social behaviors and estimate the total numbers and the densities of activated neurons per brain areas. Our study opens the door to automated screening of behavior-evoked brain activation in the mouse. PMID:25558063

  11. Brain activation during fear extinction predicts exposure success.

    Science.gov (United States)

    Ball, Tali Manber; Knapp, Sarah E; Paulus, Martin P; Stein, Murray B

    2017-03-01

    Exposure therapy, a gold-standard treatment for anxiety disorders, is assumed to work via extinction learning, but this has never been tested. Anxious individuals demonstrate extinction learning deficits, likely related to less ventromedial prefrontal cortex (vmPFC) and more amygdala activation, but the relationship between these deficits and exposure outcome is unknown. We tested whether anxious individuals who demonstrate better extinction learning report greater anxiety reduction following brief exposure. Twenty-four adults with public speaking anxiety completed (1) functional magnetic resonance imaging during a conditioning paradigm, (2) a speech exposure session, and (3) anxiety questionnaires before and two weeks postexposure. Extinction learning was assessed by comparing ratings to a conditioned stimulus (neutral image) that was previously paired with an aversive noise against a stimulus that had never been paired. Robust regression analyses examined whether brain activation during extinction learning predicted anxiety reduction two weeks postexposure. On average, the conditioning paradigm resulted in acquisition and extinction effects on stimulus ratings, and the exposure session resulted in reduced anxiety two weeks post-exposure. Consistent with our hypothesis, individuals with better extinction learning (less negative stimulus ratings), greater activation in vmPFC, and less activation in amygdala, insula, and periaqueductal gray reported greater anxiety reduction two weeks postexposure. To our knowledge, this is the first time that the theoretical link between extinction learning and exposure outcome has been demonstrated. Future work should examine whether extinction learning can be used as a prognostic test to determine who is most likely to benefit from exposure therapy. © 2016 Wiley Periodicals, Inc.

  12. Exercise modulates redox-sensitive small GTPase activity in the brain microvasculature in a model of brain metastasis formation.

    Directory of Open Access Journals (Sweden)

    Gretchen Wolff

    Full Text Available Tumor cell extravasation into the brain requires passage through the blood-brain barrier (BBB. There is evidence that exercise can alter the oxidation status of the brain microvasculature and protect against tumor cell invasion into the brain, although the mechanisms are not well understood. In the current study, we focused on the role of microenvironment generated by exercise and metastasizing tumor cells at the levels of brain microvessels, influencing oxidative stress-mediated responses and activation of redox-sensitive small GTPases. Mature male mice were exercised for four weeks using a running wheel with the average voluntary running distance 9.0 ± 0.3 km/day. Mice were then infused with 1.0 × 10(6 D122 (murine Lewis lung carcinoma cells into the brain microvasculature, and euthanized either 48 hours (in short-term studies or 2-3 weeks (in long-term studies post tumor cell administration. A significant increase in the level of reactive oxygen species was observed following 48 hours or 3 weeks of tumor cells growth, which was accompanied by a reduction in MnSOD expression in the exercised mice. Activation of the small GTPase Rho was negatively correlated with running distance in the tumor cell infused mice. Together, these data suggest that exercise may play a significant role during aggressive metastatic invasion, especially at higher intensities in pre-trained individuals.

  13. Brain Activity while Reading Sentences with Kanji Characters Expressing Emotions

    Science.gov (United States)

    Yuasa, Masahide; Saito, Keiichi; Mukawa, Naoki

    In this paper, we describe the brain activity associated with kanji characters expressing emotion, which are places at the end of a sentence. Japanese people use a special kanji character in brackets at the end of sentences in text messages such as those sent through e-mail and messenger tools. Such kanji characters plays a role to expresses the sender's emotion (such as fun, laughter, sadness, tears), like emoticons. It is a very simple and effective way to convey the senders' emotions and his/her thoughts to the receiver. In this research, we investigate the effects of emotional kanji characters by using an fMRI study. The experimental results show that both the right and left inferior frontal gyrus, which have been implicated on verbal and nonverbal information, were activated. We found that we detect a sentence with an emotional kanji character as the verbal and nonverval information, and a sentence with emotional kanji characters enrich communication between the sender and the reciever.

  14. Experimental human endotoxemia enhances brain activity during social cognition.

    Science.gov (United States)

    Kullmann, Jennifer S; Grigoleit, Jan-Sebastian; Wolf, Oliver T; Engler, Harald; Oberbeck, Reiner; Elsenbruch, Sigrid; Forsting, Michael; Schedlowski, Manfred; Gizewski, Elke R

    2014-06-01

    Acute peripheral inflammation with corresponding increases in peripheral cytokines affects neuropsychological functions and induces depression-like symptoms. However, possible effects of increased immune responses on social cognition remain unknown. Therefore, this study investigated the effects of experimentally induced acute inflammation on performance and neural responses during a social cognition task assessing Theory of Mind (ToM) ability. In this double-blind randomized crossover functional magnetic resonance imaging study, 18 healthy right-handed male volunteers received an injection of bacterial lipopolysaccharide (LPS; 0.4 ng/kg) or saline, respectively. Plasma levels of pro- and anti-inflammatory cytokines as well as mood ratings were analyzed together with brain activation during a validated ToM task (i.e. Reading the Mind in the Eyes Test). LPS administration induced pronounced transient increases in pro- (IL-6, TNF-α) and anti-inflammatory (IL-10, IL-1ra) cytokines as well as decreases in mood. Social cognition performance was not affected by acute inflammation. However, altered neural activity was observed during the ToM task after LPS administration, reflected by increased responses in the fusiform gyrus, temporo-parietal junction, superior temporal gyrus and precuneus. The increased task-related neural responses in the LPS condition may reflect a compensatory strategy or a greater social cognitive processing as a function of sickness. © The Author (2013). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

  15. Enhancing physical activity and brain reorganization after stroke.

    Science.gov (United States)

    Carr, Janet H; Shepherd, Roberta B

    2011-01-01

    It is becoming increasingly clear that, if reorganization of brain function is to be optimal after stroke, there needs to be a reorganisation of the methods used in physical rehabilitation and the time spent in specific task practice, strength and endurance training, and aerobic exercise. Frequency and intensity of rehabilitation need to be increased so that patients can gain the energy levels and vigour necessary for participation in physical activity both during rehabilitation and after discharge. It is evident that many patients are discharged from inpatient rehabilitation severely deconditioned, meaning that their energy levels are too low for active participation in daily life. Physicians, therapists, and nursing staff responsible for rehabilitation practice should address this issue not only during inpatient rehabilitation but also after discharge by promoting and supporting community-based exercise opportunities. During inpatient rehabilitation, group sessions should be frequent and need to include specific aerobic training. Physiotherapy must take advantage of the training aids available, including exercise equipment such as treadmills, and of new developments in computerised feedback systems, robotics, and electromechanical trainers. For illustrative purposes, this paper focuses on the role of physiotherapists, but the necessary changes in practice and in attitude will require cooperation from many others.

  16. Enhancing Physical Activity and Brain Reorganization after Stroke

    Directory of Open Access Journals (Sweden)

    Janet H. Carr

    2011-01-01

    Full Text Available It is becoming increasingly clear that, if reorganization of brain function is to be optimal after stroke, there needs to be a reorganisation of the methods used in physical rehabilitation and the time spent in specific task practice, strength and endurance training, and aerobic exercise. Frequency and intensity of rehabilitation need to be increased so that patients can gain the energy levels and vigour necessary for participation in physical activity both during rehabilitation and after discharge. It is evident that many patients are discharged from inpatient rehabilitation severely deconditioned, meaning that their energy levels are too low for active participation in daily life. Physicians, therapists, and nursing staff responsible for rehabilitation practice should address this issue not only during inpatient rehabilitation but also after discharge by promoting and supporting community-based exercise opportunities. During inpatient rehabilitation, group sessions should be frequent and need to include specific aerobic training. Physiotherapy must take advantage of the training aids available, including exercise equipment such as treadmills, and of new developments in computerised feedback systems, robotics, and electromechanical trainers. For illustrative purposes, this paper focuses on the role of physiotherapists, but the necessary changes in practice and in attitude will require cooperation from many others.

  17. Marine biomolecules inhibit rat brain nitric oxide synthase activity.

    Science.gov (United States)

    Venkateswara Rao, J; Desaiah, D; Vig, P J; Venkateswarlu, Y

    1998-08-21

    A large number of substances of medical importance have been isolated from marine flora and fauna and their chemical structures were elucidated. Among the many compounds isolated in our laboratories only two compounds were identified as neurotoxins as they produced depolarizing effects in nerve fibers. The Xestospongin D and Araguspongin C, isolated and purified to 100% from sponge, Haliclona exigua were tested for their effects on rat brain nitric oxide synthase (NOS) activity in vitro. The results showed that NOS activity was significantly inhibited in a concentration and time dependent manner with an estimated IC50 of 31.5 and 46.5 microM for Xestospongin D and Araguspongin C, respectively, and the maximum inhibition occurred within 3 min of incubation. To explore the mechanism of action of these compounds on NOS, we have conducted kinetic studies with L-arginine, NADPH and Ca2+ in the presence of IC50 concentrations of these two compounds. The maximum velocity (Vmax) and enzyme constant (Km) were calculated using the Michaelis Menten equation. The results show that both compounds are competitive inhibitors of NOS with the substrate, L-arginine and uncompetitive with NADPH and free Ca2+. The NOS inhibition by these two compounds was similar to N omega-nitro-L-arginine methylester (L-NAME), a known inhibitor of NOS. These results suggest that the marine biomolecules Xestospongin D and Araguspongin C are in vitro modulators of neuronal NOS.

  18. Brain activation in a myoelectric prosthetic hand: the role of the brain in the rehabilitation of amputees.

    Science.gov (United States)

    da Paz, Aloysio Campos; Braga, Lucia Willadino

    2007-12-01

    Historically, rehabilitation of amputees has focused on developing prostheses, adjusting them to fit the limb, and then submitting the patient to extensive "training" programs. The objective of this study was to investigate whether stimuli from the sensorimotor cortex, observed through functional magnetic resonance imaging, comprises a neuronal network that permits the control of a myoelectric prosthetic hand. A comprehensive review of the subject was conducted, and a specific case is presented to illustrate the hypothesis. In a self-controlled designed study, a 13-year-old girl with congenital amputation of the right hand was tested to verify if the brain can control fine motor movement of a myoelectric prosthetic hand. Functional magnetic resonance images were conducted to assess whether there was a relationship between brain activation and control of the prosthesis. Functional magnetic resonance imaging data were collected to investigate brain activation during the actual opening and closing of the existent hand and during the contraction of the remaining stump muscles used for opening and closing the myoelectric prosthetic hand. Similar activation was found in the brain hemispheres that control the myoelectric and existing hands. When the patient moved the prosthetic hand, activation was observed in the brain's sensorimotor and visual cortexes and the cerebellum. These data suggest that the patient was controlling and also perceiving that the artificial hand was performing movements. This study suggests that it may be possible to control speed, force, and modulation of a myoelectric prosthesis through impulses emitted by specific brain areas. Further research in brain control and improvement of myoelectric prosthesis will lead to a more holistic approach in the development of a man-machine complex.

  19. Application of subharmonics for active sound design of electric vehicles.

    Science.gov (United States)

    Gwak, Doo Young; Yoon, Kiseop; Seong, Yeolwan; Lee, Soogab

    2014-12-01

    The powertrain of electric vehicles generates an unfamiliar acoustical environment for customers. This paper seeks optimal interior sound for electric vehicles based on psychoacoustic knowledge and musical harmonic theory. The concept of inserting a virtual sound, which consists of the subharmonics of an existing high-frequency component, is suggested to improve sound quality. Subjective evaluation results indicate that the impression of interior sound can be enhanced in this manner. Increased appeal is achieved through two designed stimuli, which proves the effectiveness of the method proposed.

  20. Cocaine is pharmacologically active in the nonhuman primate fetal brain

    DEFF Research Database (Denmark)

    Benveniste, Helene; Fowler, Joanna S; Rooney, William D

    2010-01-01

    -trimester pregnant nonhuman primates, cocaine at doses typically used by drug abusers significantly increased brain glucose metabolism to the same extent in the mother as in the fetus (approximately 100%). Inasmuch as brain glucose metabolism is a sensitive marker of brain function, the current findings provide......Cocaine use during pregnancy is deleterious to the newborn child, in part via its disruption of placental blood flow. However, the extent to which cocaine can affect the function of the fetal primate brain is still an unresolved question. Here we used PET and MRI and show that in third...... evidence that cocaine use by a pregnant mother will also affect the function of the fetal brain. We are also unique in showing that cocaine's effects in brain glucose metabolism differed in pregnant (increased) and nonpregnant (decreased) animals, which suggests that the psychoactive effects of cocaine...

  1. Biophysical Model of Cortical Network Activity and the Influence of Electrical Stimulation

    Science.gov (United States)

    2015-11-13

    SECURITY CLASSIFICATION OF: We examined the effects of subdural electrical stimulation on a high-density network consisting of several populations of...multicompartment cell types. The results can be summarized as follows: 1) Electrical stimulation mainly affects and activates axon initial and the most...of Electrical Stimulation . The views, opinions and/or findings contained in this report are those of the author(s) and should not contrued as an

  2. The creative brain: investigation of brain activity during creative problem solving by means of EEG and FMRI.

    Science.gov (United States)

    Fink, Andreas; Grabner, Roland H; Benedek, Mathias; Reishofer, Gernot; Hauswirth, Verena; Fally, Maria; Neuper, Christa; Ebner, Franz; Neubauer, Aljoscha C

    2009-03-01

    Cortical activity in the EEG alpha band has proven to be particularly sensitive to creativity-related demands, but its functional meaning in the context of creative cognition has not been clarified yet. Specifically, increases in alpha activity (i.e., alpha synchronisation) in response to creative thinking can be interpreted in different ways: As a functional correlate of cortical idling, as a sign of internal top-down activity or, more specifically, as selective inhibition of brain regions. We measured brain activity during creative thinking in two studies employing different neurophysiological measurement methods (EEG and fMRI). In both studies, participants worked on four verbal tasks differentially drawing on creative idea generation. The EEG study revealed that the generation of original ideas was associated with alpha synchronisation in frontal brain regions and with a diffuse and widespread pattern of alpha synchronisation over parietal cortical regions. The fMRI study revealed that task performance was associated with strong activation in frontal regions of the left hemisphere. In addition, we found task-specific effects in parietotemporal brain areas. The findings suggest that EEG alpha band synchronisation during creative thinking can be interpreted as a sign of active cognitive processes rather than cortical idling.

  3. Tacit Knowledge Capture and the Brain-Drain at Electrical Utilities

    Science.gov (United States)

    Perjanik, Nicholas Steven

    As a consequence of an aging workforce, electric utilities are at risk of losing their most experienced and knowledgeable electrical engineers. In this research, the problem was a lack of understanding of what electric utilities were doing to capture the tacit knowledge or know-how of these engineers. The purpose of this qualitative research study was to explore the tacit knowledge capture strategies currently used in the industry by conducting a case study of 7 U.S. electrical utilities that have demonstrated an industry commitment to improving operational standards. The research question addressed the implemented strategies to capture the tacit knowledge of retiring electrical engineers and technical personnel. The research methodology involved a qualitative embedded case study. The theories used in this study included knowledge creation theory, resource-based theory, and organizational learning theory. Data were collected through one time interviews of a senior electrical engineer or technician within each utility and a workforce planning or training professional within 2 of the 7 utilities. The analysis included the use of triangulation and content analysis strategies. Ten tacit knowledge capture strategies were identified: (a) formal and informal on-boarding mentorship and apprenticeship programs, (b) formal and informal off-boarding mentorship programs, (c) formal and informal training programs, (d) using lessons learned during training sessions, (e) communities of practice, (f) technology enabled tools, (g) storytelling, (h) exit interviews, (i) rehiring of retirees as consultants, and (j) knowledge risk assessments. This research contributes to social change by offering strategies to capture the know-how needed to ensure operational continuity in the delivery of safe, reliable, and sustainable power.

  4. Current Directions in Non-Invasive Low Intensity Electric Brain Stimulation for Depressive Disorder

    NARCIS (Netherlands)

    Schutter, D.J.L.G.; Sack, A.T.

    2014-01-01

    Non-invasive stimulation of the human brain to improve depressive symptoms is increasingly finding its way in clinical settings as a viable form of somatic treatment. Following successful modulation of neural excitability with subsequent antidepressant effects, neural polarization by administrating

  5. Electric brain responses to inappropriate harmonies during listening to expressive music

    NARCIS (Netherlands)

    Koesch, S; Mulder, J

    Objectives: Recent studies with event-related brain potentials (ERPs) investigating music processing found (early) negativities with right-hemispheric predominance as a response to inappropriate harmonies within sequences of chords. The stimuli used in those studies were fairly artificial in order

  6. Effect of Amniotomy on Uterine Muscle Electrical Activity During Labor Induction with Oxytocin and Prostaglandins

    OpenAIRE

    Toth, Tibor

    2006-01-01

    The aim of the study was to find out whether noninvasive recording of uterine muscle electrical activity could help monitor the development of mechanical myometrial activity during induced labor. Myometrium electrical activity during labor induction was analyzed in 110 gravidas hospitalized at Maternity Ward, Bjelovar General Hospital in Bjelovar. The means used for labor induction was oxytocin infusion in 54, intracervical prostaglandin (dinoprostone 0.5 mg) in 20, intravaginal prostaglandin...

  7. CHANGES IN REGIONAL BRAIN ACTIVATION RELATED TO DEPRESSIVE STATE : A 2-YEAR LONGITUDINAL FUNCTIONAL MRI STUDY

    NARCIS (Netherlands)

    Opmeer, Esther M.; Kortekaas, Rudie; van Tol, Marie-Jose; Renken, Remco J.; Demenescu, Liliana R.; Woudstra, Saskia; Horst, ter Gert J.; van Buchem, Mark A.; van der Wee, Nic J. A.; Veltman, Dick J.; Aleman, Andre

    BackgroundAbnormal brain activations during processing of emotional facial expressions in depressed patients have been demonstrated. We investigated the natural course of brain activation in response to emotional faces in depression, indexed by functional magnetic resonance imaging (fMRI) scans

  8. Does bracing influence brain activity during knee movement: an fMRI study.

    Science.gov (United States)

    Thijs, Youri; Vingerhoets, Guy; Pattyn, Els; Rombaut, Lies; Witvrouw, Erik

    2010-08-01

    Studies have shown that proprioceptive inputs during active and passive arm movements are processed in the primary and secondary somatosensory cortex and supplementary motor area of the brain. At which level of the central nervous system proprioceptive signals coming from the knee are regulated remains to be elucidated. In order to investigate whether there is a detectable difference in brain activity when various proprioceptive inputs are exerted at the knee, functional magnetic resonance imaging (fMRI) was used. fMRI in 13 healthy, right leg-dominant female volunteers compared brain activation during flexion-extension movements of the right knee under three different conditions: with application of a tight knee brace, with application of a moderate tight knee sleeve, and without application of a brace or sleeve. Brain activation was detected in the primary sensorimotor cortex (left and right paracentral lobule) and in the left superior parietal lobule of the brain. There was a significantly higher level of brain activation with the application of the brace and sleeve, respectively, compared to the condition without a brace or sleeve. A significantly higher cortical activation was also seen when comparing the braced condition with the condition when a sleeve was applied. The results suggest that peripheral proprioceptive input to the knee joint by means of a brace or sleeve seems to influence brain activity during knee movement. The results of this study also show that the intensity of brain activation during knee movement can be influenced by the intensity of proprioceptive stimulation at the joint.

  9. Spatial Rotation and Recognizing Emotions: Gender Related Differences in Brain Activity

    Science.gov (United States)

    Jausovec, Norbert; Jausovec, Ksenija

    2008-01-01

    In three experiments, gender and ability (performance and emotional intelligence) related differences in brain activity--assessed with EEG methodology--while respondents were solving a spatial rotation tasks and identifying emotions in faces were investigated. The most robust gender related difference in brain activity was observed in the lower-2…

  10. External cardiac compression may be harmful in some scenarios of pulseless electrical activity.

    LENUS (Irish Health Repository)

    Hogan, T S

    2012-10-01

    Pulseless electrical activity occurs when organised or semi-organised electrical activity of the heart persists but the product of systemic vascular resistance and the increase in systemic arterial flow generated by the ejection of the left venticular stroke volume is not sufficient to produce a clinically detectable pulse. Pulseless electrical activity encompasses a very heterogeneous variety of severe circulatory shock states ranging in severity from pseudo-cardiac arrest to effective cardiac arrest. Outcomes of cardiopulmonary resuscitation for pulseless electrical activity are generally poor. Impairment of cardiac filling is the limiting factor to cardiac output in many scenarios of pulseless electrical activity, including extreme vasodilatory shock states. There is no evidence that external cardiac compression can increase cardiac output when impaired cardiac filling is the limiting factor to cardiac output. If impaired cardiac filling is the limiting factor to cardiac output and the heart is effectively ejecting all the blood returning to it, then external cardiac compression can only increase cardiac output if it increases venous return and cardiac filling. Repeated cardiac compression asynchronous with the patient\\'s cardiac cycle and raised mean intrathoracic pressure due to chest compression can be expected to reduce rather than to increase cardiac filling and therefore to reduce rather than to increase cardiac output in such circumstances. The hypothesis is proposed that the performance of external cardiac compression will have zero or negative effect on cardiac output in pulseless electrical activity when impaired cardiac filling is the limiting factor to cardiac output. External cardiac compression may be both directly and indirectly harmful to significant sub-groups of patients with pulseless electrical activity. We have neither evidence nor theory to provide comfort that external cardiac compression is not harmful in many scenarios of pulseless

  11. Casein kinase II activity in the brain of an insect, Acheta domesticus: characterization and hormonal regulation.

    Science.gov (United States)

    Degrelle, F; Renucci, M; Charpin, P; Tirard, A

    1997-01-01

    This study documented casein kinase II (CK II) activity in Acheta domesticus brain using specific antibodies and its regulation by polyamines. In control animals a transient decrease in CK II activity at day 3 after imaginal moult was observed in the brain but not in the fat body. If deprived of ecdysone by ovariectomy a different pattern was observed, with CK II activity being significantly higher on days 3 and 4 after emergence. After ecdysone injection in ovariectomized females, CK II activity decreased to levels similar to those in controls. The implications of ecdysone regulation of brain CK II activity are discussed.

  12. How does transcranial magnetic stimulation modify neuronal activity in the brain? Implications for studies of cognition

    DEFF Research Database (Denmark)

    Siebner, Hartwig R; Hartwigsen, Gesa; Kassuba, Tanja

    2009-01-01

    Transcranial magnetic stimulation (TMS) uses a magnetic field to "carry" a short lasting electrical current pulse into the brain where it stimulates neurones, particularly in superficial regions of cerebral cortex. TMS can interfere with cognitive functions in two ways. A high intensity TMS pulse...

  13. [The utilization of brain plasticity by cochlear implants : Molecular and cellular changes due to electrical intracochlear stimulation].

    Science.gov (United States)

    Rosskothen-Kuhl, N; Illing, R-B

    2015-02-01

    During pre- and postnatal development, a high level of growth-associated protein 43 (Gap43) is expressed in the brain. This neuron-specific protein is expressed in somata, axons, and growth cones and plays a key role in neurite outgrowth and synaptogenesis. With maturation of the brain, Gap43 is down-regulated by most neurons, except in brain areas such as the hippocampal CA3 region or the binaural auditory regions lateral superior olive (LSO) and central inferior colliculus (CIC). This study investigated how changes in sensory activity levels and patterns can modulate the adult plasticity response. To study the effect of sensory activity on adult Gap43 expression, mRNA and protein levels were determined in LSO and CIC of hearing-experienced rats, unilaterally and bilaterally deafened rats, or rats unilaterally stimulated by a cochlear implant (CI). Unilateral hearing loss of an adult auditory system causes asymmetrical expression of Gap43 mRNA between ipsi- and contralateral LSOs or CICs of the brain stem. While the mRNA level rose on the contralateral side of the LSO, CIC neurons increased their gap43 transcription ipsilaterally compared to the control level (pstimulation resulted in a bilaterally symmetric but increased gap43 transcription. Our data indicate that Gap43 is not only a marker for neuronal growth and synaptogenesis, but also reflects modified patterns of synaptic activities on auditory neurons. Thus, unilateral deafness directly results in an asymmetrical adaptation of the gap43 transcription between both sides of the auditory brain stem. This can be prevented by simple-patterned stimulation of the auditory nerve via a CI.

  14. Non-Invasive Characterization of Brain Tissue Electrical Properties with MRI

    NARCIS (Netherlands)

    Mandija, Stefano

    2017-01-01

    The study of the electrical properties (EPs) of tissues, i.e. conductivity and permittivity, is of fundamental importance to understand the biophysical interactions and the effects of electromagnetic fields on our body, such as those produced by MRI scanners or by Transcranial Magnetic Stimulators

  15. Acute and chronic changes in brain activity with deep brain stimulation for refractory depression.

    Science.gov (United States)

    Conen, Silke; Matthews, Julian C; Patel, Nikunj K; Anton-Rodriguez, José; Talbot, Peter S

    2017-12-01

    Deep brain stimulation is a potential option for patients with treatment-refractory depression. Deep brain stimulation benefits have been reported when targeting either the subgenual cingulate or ventral anterior capsule/nucleus accumbens. However, not all patients respond and optimum stimulation-site is uncertain. We compared deep brain stimulation of the subgenual cingulate and ventral anterior capsule/nucleus accumbens separately and combined in the same seven treatment-refractory depression patients, and investigated regional cerebral blood flow changes associated with acute and chronic deep brain stimulation. Deep brain stimulation-response was defined as reduction in Montgomery-Asberg Depression Rating Scale score from baseline of ≥50%, and remission as a Montgomery-Asberg Depression Rating Scale score ≤8. Changes in regional cerebral blood flow were assessed using [15O]water positron emission tomography. Remitters had higher relative regional cerebral blood flow in the prefrontal cortex at baseline and all subsequent time-points compared to non-remitters and non-responders, with prefrontal cortex regional cerebral blood flow generally increasing with chronic deep brain stimulation. These effects were consistent regardless of stimulation-site. Overall, no significant regional cerebral blood flow changes were apparent when deep brain stimulation was acutely interrupted. Deep brain stimulation improved treatment-refractory depression severity in the majority of patients, with consistent changes in local and distant brain regions regardless of target stimulation. Remission of depression was reached in patients with higher baseline prefrontal regional cerebral blood flow. Because of the small sample size these results are preliminary and further evaluation is necessary to determine whether prefrontal cortex regional cerebral blood flow could be a predictive biomarker of treatment response.

  16. Sustained Treatment with Insulin Detemir in Mice Alters Brain Activity and Locomotion.

    Directory of Open Access Journals (Sweden)

    Tina Sartorius

    Full Text Available Recent studies have identified unique brain effects of insulin detemir (Levemir®. Due to its pharmacologic properties, insulin detemir may reach higher concentrations in the brain than regular insulin. This might explain the observed increased brain stimulation after acute insulin detemir application but it remained unclear whether chronic insulin detemir treatment causes alterations in brain activity as a consequence of overstimulation.In mice, we examined insulin detemir's prolonged brain exposure by continuous subcutaneous (s.c. application using either micro-osmotic pumps or daily s.c. injections and performed continuous radiotelemetric electrocorticography and locomotion recordings.Acute intracerebroventricular injection of insulin detemir activated cortical and locomotor activity significantly more than regular insulin in equimolar doses (0.94 and 5.63 mU in total, suggesting an enhanced acute impact on brain networks. However, given continuously s.c., insulin detemir significantly reduced cortical activity (theta: 21.3±6.1% vs. 73.0±8.1%, P<0.001 and failed to maintain locomotion, while regular insulin resulted in an increase of both parameters.The data suggest that permanently-increased insulin detemir levels in the brain convert its hyperstimulatory effects and finally mediate impairments in brain activity and locomotion. This observation might be considered when human studies with insulin detemir are designed to target the brain in order to optimize treatment regimens.

  17. Cocaine is pharmacologically active in the nonhuman primate fetal brain

    DEFF Research Database (Denmark)

    Benveniste, Helene; Fowler, Joanna S; Rooney, William D

    2010-01-01

    -trimester pregnant nonhuman primates, cocaine at doses typically used by drug abusers significantly increased brain glucose metabolism to the same extent in the mother as in the fetus (approximately 100%). Inasmuch as brain glucose metabolism is a sensitive marker of brain function, the current findings provide...... evidence that cocaine use by a pregnant mother will also affect the function of the fetal brain. We are also unique in showing that cocaine's effects in brain glucose metabolism differed in pregnant (increased) and nonpregnant (decreased) animals, which suggests that the psychoactive effects of cocaine...... are influenced by the state of pregnancy. Our findings have clinical implications because they imply that the adverse effects of prenatal cocaine exposure to the newborn child include not only cocaine's deleterious effects to the placental circulation, but also cocaine's direct pharmacological effect...

  18. Brain Basics

    Medline Plus

    Full Text Available ... Brain Research Glossary Brain Basics (PDF, 10 pages) Introduction Watch the Brain Basics video Welcome. Brain Basics ... fear hub," which activates our natural "fight-or-flight" response to confront or escape from a dangerous ...

  19. Estimating cognitive load during self-regulation of brain activity and neurofeedback with therapeutic brain-computer interfaces.

    Science.gov (United States)

    Bauer, Robert; Gharabaghi, Alireza

    2015-01-01

    Neurofeedback (NFB) training with brain-computer interfaces (BCIs) is currently being studied in a variety of neurological and neuropsychiatric conditions in an aim to reduce disorder-specific symptoms. For this purpose, a range of classification algorithms has been explored to identify different brain states. These neural states, e.g., self-regulated brain activity vs. rest, are separated by setting a threshold parameter. Measures such as the maximum classification accuracy (CA) have been introduced to evaluate the performance of these algorithms. Interestingly enough, precisely these measures are often used to estimate the subject's ability to perform brain self-regulation. This is surprising, given that the goal of improving the tool that differentiates between brain states is different from the aim of optimizing NFB for the subject performing brain self-regulation. For the latter, knowledge about mental resources and work load is essential in order to adapt the difficulty of the intervention accordingly. In this context, we apply an analytical method and provide empirical data to determine the zone of proximal development (ZPD) as a measure of a subject's cognitive resources and the instructional efficacy of NFB. This approach is based on a reconsideration of item-response theory (IRT) and cognitive load theory for instructional design, and combines them with the CA curve to provide a measure of BCI performance.

  20. Estimating cognitive load during self-regulation of brain activity and neurofeedback with therapeutic brain-computer interfaces

    Directory of Open Access Journals (Sweden)

    Robert eBauer

    2015-02-01

    Full Text Available Neurofeedback training with brain-computer interfaces is currently studied in a variety of neurological and neuropsychiatric conditions to reduce disorder-specific symptoms. For this purpose, a variety of classification algorithms have been explored to distinguish different brain states. These neural states, e.g. self-regulated brain activity versus rest, are separated by setting a threshold parameter. Measures such as the maximum classification accuracy have been introduced to evaluate the performance of these algorithms. Interestingly, the very same measures are often used to estimate the subject’s ability to perform brain self-regulation. This is surprising, as the goal of improving the tool that differentiates brain states is different from the aim of optimizing neurofeedback for the subject who performs brain self-regulation. For the latter, knowledge about mental resources and work load is essential to adapt the difficulty of the intervention.In this context, we apply an analytical method and provide empirical data to determine the zone of proximal development as a measure of a subject’s cognitive resources and the instructional efficacy of neurofeedback. This approach is based on a reconsideration of item-response theory and cognitive load theory for instructional design, and combines them with the classification accuracy curve as a measure of BCI performance.

  1. Development of modularity in the neural activity of children's brains.

    Science.gov (United States)

    Chen, Man; Deem, Michael W

    2015-01-26

    We study how modularity of the human brain changes as children develop into adults. Theory suggests that modularity can enhance the response function of a networked system subject to changing external stimuli. Thus, greater cognitive performance might be achieved for more modular neural activity, and modularity might likely increase as children develop. The value of modularity calculated from functional magnetic resonance imaging (fMRI) data is observed to increase during childhood development and peak in young adulthood. Head motion is deconvolved from the fMRI data, and it is shown that the dependence of modularity on age is independent of the magnitude of head motion. A model is presented to illustrate how modularity can provide greater cognitive performance at short times, i.e. task switching. A fitness function is extracted from the model. Quasispecies theory is used to predict how the average modularity evolves with age, illustrating the increase of modularity during development from children to adults that arises from selection for rapid cognitive function in young adults. Experiments exploring the effect of modularity on cognitive performance are suggested. Modularity may be a potential biomarker for injury, rehabilitation, or disease.

  2. Normal brain activation in schizophrenia patients during associative emotional learning.

    Science.gov (United States)

    Swart, Marte; Liemburg, Edith Jantine; Kortekaas, Rudie; Wiersma, Durk; Bruggeman, Richard; Aleman, André

    2013-12-30

    Emotional deficits are among the core features of schizophrenia and both associative emotional learning and the related ability to verbalize emotions can be reduced. We investigated whether schizophrenia patients demonstrated impaired function of limbic and prefrontal areas during associative emotional learning. Patients and controls filled out an alexithymia questionnaire and performed an associative emotional learning task with positive, negative and neutral picture-word pairs during fMRI scanning. After scanning, they indicated for each pair whether they remembered it. We conducted standard GLM analysis and Independent Component Analysis (ICA). Both the GLM results and task-related ICA components were compared between groups. The alexithymia questionnaire indicated more cognitive-emotional processing difficulties in patients than controls, but equal experienced intensity of affective states. Patients remembered less picture-word pairs, irrespective of valence. GLM analysis showed significant visual, temporal, amygdalar/hippocampal, and prefrontal activation in all subjects. ICA identified a network of brain areas similar to GLM, mainly in response to negative stimuli. Neither analysis showed differences between patients and controls during learning. Although in previous studies schizophrenia patients showed abnormalities in both memory and emotion processing, neural circuits involved in cross-modal associative emotional learning may remain intact to a certain degree, which may have potential consequences for treatment. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  3. Transcutaneus electrical nerve stimulation for overactive bladder increases rectal motor activity in children: a randomized controlled study

    DEFF Research Database (Denmark)

    Jønsson, Iben; Hagstrøm, Søren; Siggaard, Charlotte

    Transcutaneus electrical nerve stimulation for overactive bladder increases rectal motor activity in children: a randomized controlled study......Transcutaneus electrical nerve stimulation for overactive bladder increases rectal motor activity in children: a randomized controlled study...

  4. Measurable benefits on brain activity from the practice of educational leisure

    OpenAIRE

    Carmen eRequena

    2014-01-01

    Even if behavioural studies relate leisure practices to the preservation of memory in old persons, there is unsubstantial evidence of the import of leisure on brain activity. Aim of this study was to compare the brain activity of elderly retired people who engage in different types of leisure activities. Methods: quasi-experimental study over a sample of 60 elderly, retired subjects distributed into three groups according to the leisure activities they practised: educational leisure (G1), mem...

  5. Measurable benefits on brain activity from the practice of educational leisure

    OpenAIRE

    Requena, Carmen; López,Verónica

    2014-01-01

    Even if behavioral studies relate leisure practices to the preservation of memory in old persons, there is unsubstantial evidence of the import of leisure on brain activity. Aim: This study was to compare the brain activity of elderly retired people who engage in different types of leisure activities. Methods: Quasi-experimental study over a sample of 60 elderly, retired subjects distributed into three groups according to the leisure activities they practised: educational leisure (G1), ...

  6. Electrical Brain Responses to an Auditory Illusion and the Impact of Musical Expertise.

    Directory of Open Access Journals (Sweden)

    Christos I Ioannou

    Full Text Available The presentation of two sinusoidal tones, one to each ear, with a slight frequency mismatch yields an auditory illusion of a beating frequency equal to the frequency difference between the two tones; this is known as binaural beat (BB. The effect of brief BB stimulation on scalp EEG is not conclusively demonstrated. Further, no studies have examined the impact of musical training associated with BB stimulation, yet musicians' brains are often associated with enhanced auditory processing. In this study, we analysed EEG brain responses from two groups, musicians and non-musicians, when stimulated by short presentation (1 min of binaural beats with beat frequency varying from 1 Hz to 48 Hz. We focused our analysis on alpha and gamma band EEG signals, and they were analysed in terms of spectral power, and functional connectivity as measured by two phase synchrony based measures, phase locking value and phase lag index. Finally, these measures were used to characterize the degree of centrality, segregation and integration of the functional brain network. We found that beat frequencies belonging to alpha band produced the most significant steady-state responses across groups. Further, processing of low frequency (delta, theta, alpha binaural beats had significant impact on cortical network patterns in the alpha band oscillations. Altogether these results provide a neurophysiological account of cortical responses to BB stimulation at varying frequencies, and demonstrate a modulation of cortico-cortical connectivity in musicians' brains, and further suggest a kind of neuronal entrainment of a linear and nonlinear relationship to the beating frequencies.

  7. Electrical Brain Responses to an Auditory Illusion and the Impact of Musical Expertise

    Science.gov (United States)

    Ioannou, Christos I.; Pereda, Ernesto; Lindsen, Job P.; Bhattacharya, Joydeep

    2015-01-01

    The presentation of two sinusoidal tones, one to each ear, with a slight frequency mismatch yields an auditory illusion of a beating frequency equal to the frequency difference between the two tones; this is known as binaural beat (BB). The effect of brief BB stimulation on scalp EEG is not conclusively demonstrated. Further, no studies have examined the impact of musical training associated with BB stimulation, yet musicians' brains are often associated with enhanced auditory processing. In this study, we analysed EEG brain responses from two groups, musicians and non-musicians, when stimulated by short presentation (1 min) of binaural beats with beat frequency varying from 1 Hz to 48 Hz. We focused our analysis on alpha and gamma band EEG signals, and they were analysed in terms of spectral power, and functional connectivity as measured by two phase synchrony based measures, phase locking value and phase lag index. Finally, these measures were used to characterize the degree of centrality, segregation and integration of the functional brain network. We found that beat frequencies belonging to alpha band produced the most significant steady-state responses across groups. Further, processing of low frequency (delta, theta, alpha) binaural beats had significant impact on cortical network patterns in the alpha band oscillations. Altogether these results provide a neurophysiological account of cortical responses to BB stimulation at varying frequencies, and demonstrate a modulation of cortico-cortical connectivity in musicians' brains, and further suggest a kind of neuronal entrainment of a linear and nonlinear relationship to the beating frequencies. PMID:26065708

  8. Resting brain activity varies with dream recall frequency between subjects.

    Science.gov (United States)

    Eichenlaub, Jean-Baptiste; Nicolas, Alain; Daltrozzo, Jérôme; Redouté, Jérôme; Costes, Nicolas; Ruby, Perrine

    2014-06-01

    Dreaming is still poorly understood. Notably, its cerebral underpinning remains unclear. Neuropsychological studies have shown that lesions in the temporoparietal junction (TPJ) and/or the white matter of the medial prefrontal cortex (MPFC) lead to the global cessation of dream reports, suggesting that these regions of the default mode network have key roles in the dreaming process (forebrain 'dream-on' hypothesis). To test this hypothesis, we measured regional cerebral blood flow (rCBF) using [(15)O]H2O positron emission tomography in healthy subjects with high and low dream recall frequencies (DRFs) during wakefulness (rest) and sleep (rapid eye movement (REM) sleep, N2, and N3). Compared with Low recallers (0.5 ± 0.3 dream recall per week in average), High recallers (5.2 ± 1.4) showed higher rCBF in the TPJ during REM sleep, N3, and wakefulness, and in the MPFC during REM sleep and wakefulness. We demonstrate that the resting states of High recallers and Low recallers differ during sleep and wakefulness. It coheres with previous ERP results and confirms that a high/low DRF is associated with a specific functional organization of the brain. These results support the forebrain 'dream-on' hypothesis and suggest that TPJ and MPFC are not only involved in dream recall during wakefulness but also have a role in dreaming during sleep (production and/or encoding). Increased activity in the TPJ and MPFC might promote the mental imagery and/or memory encoding of dreams. Notably, increased activity in TPJ might facilitate attention orienting toward external stimuli and promote intrasleep wakefulness, facilitating the encoding of the dreams in memory.

  9. Material and physical model for evaluation of deep brain activity contribution to EEG recordings

    Science.gov (United States)

    Ye, Yan; Li, Xiaoping; Wu, Tiecheng; Li, Zhe; Xie, Wenwen

    2015-12-01

    Deep brain activity is conventionally recorded with surgical implantation of electrodes. During the neurosurgery, brain tissue damage and the consequent side effects to patients are inevitably incurred. In order to eliminate undesired risks, we propose that deep brain activity should be measured using the noninvasive scalp electroencephalography (EEG) technique. However, the deeper the neuronal activity is located, the noisier the corresponding scalp EEG signals are. Thus, the present study aims to evaluate whether deep brain activity could be observed from EEG recordings. In the experiment, a three-layer cylindrical head model was constructed to mimic a human head. A single dipole source (sine wave, 10 Hz, altering amplitudes) was embedded inside the model to simulate neuronal activity. When the dipole source was activated, surface potential was measured via electrodes attached on the top surface of the model and raw data were recorded for signal analysis. Results show that the dipole source activity positioned at 66 mm depth in the model, equivalent to the depth of deep brain structures, is clearly observed from surface potential recordings. Therefore, it is highly possible that deep brain activity could be observed from EEG recordings and deep brain activity could be measured using the noninvasive scalp EEG technique.

  10. Electric-current Neutralization, Magnetic Shear, and Eruptive Activity in Solar Active Regions

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yang; Sun, Xudong [W. W. Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA 94305-4085 (United States); Török, Tibor; Titov, Viacheslav S. [Predictive Science Inc., 9990 Mesa Rim Road, Suite 170, San Diego, CA 92121 (United States); Leake, James E. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

    2017-09-01

    The physical conditions that determine whether or not solar active regions (ARs) produce strong flares and coronal mass ejections (CMEs) are not yet well understood. Here, we investigate the association between electric-current neutralization, magnetic shear along polarity inversion lines (PILs), and eruptive activity in four ARs: two emerging and two well-developed ones. We find that the CME-producing ARs are characterized by a strongly non-neutralized total current, while the total current in the ARs that did not produce CMEs is almost perfectly neutralized. The difference in the PIL shear between these two groups is much less pronounced, which suggests that the degree of current neutralization may serve as a better proxy for assessing the ability of ARs to produce CMEs.

  11. Effect of metal fragments in brain on electrical monitoring: In vitro and in vivo rat studies

    Science.gov (United States)

    Ahmed, A.; Bodo, M.; Armonda, R. A.

    2010-04-01

    Preliminary results showed, measurements by rheoencephalography (REG) very promising as a practical, noninvasive continuous monitoring modality of traumatic brain/blast injuries. As the impact of metal fragments on the REG signal is unknown, we report here results of our study .The in vitro study confirmed that impedance pulse amplitude waves do not change in the presence of metal (needles) placed between electrodes. In vivo studies: rats under anesthesia (10 rats, 101 trials) were measured after implantation of EEG and REG electrodes in the brain. Metal fragments were represented by 18 g needles inserted and removed between EEG and REG electrodes. Data were stored in a PC. EEG recording typically showed amplitude decrease; REG showed transitory amplitude increase after placement of a needle into either hemisphere. Removal of needles caused a decrease in REG amplitude after a transitory increase. The change in REG amplitude statistically was non-significant. Cerebral blood flow (CBF) autoregulation(AR) persisted following placement of metal fragments in rat brain.

  12. Physical activity, structural brain changes and cognitive decline. The SMART-MR study.

    Science.gov (United States)

    Kooistra, M; Boss, H M; van der Graaf, Y; Kappelle, L J; Biessels, G J; Geerlings, M I

    2014-05-01

    We aimed to examine the cross-sectional and prospective relationship between leisure time physical activity, brain MRI abnormalities and cognitive performance in patients with vascular disease. Within the SMART-MR study, 1.5 T MRI of the brain and neuropsychological examinations were performed at baseline (n = 1232) and after 3.9 ± 0.4 years follow-up (n = 663). Automatic brain segmentation was used to quantify intracranial (ICV), total brain, ventricular, and white matter lesion (WML) volumes. Brain infarcts were rated visually. Level of physical activity was expressed in metabolic equivalents (MET) hours p/week. With linear regression analysis we examined associations of level of physical activity with brain MRI measures and with cognitive performance, adjusted for potential confounders. For the association with brain infarcts relative risks (RR) were calculated with Poisson regression. At baseline, an increase in physical activity of one SD (39.7 METh/w) was significantly associated with larger total brain volume (B = 0.20% of ICV; 95% CI 0.06; 0.33%). A trend was found for the association of physical activity with smaller ventricular volume (B = -0.04% of ICV; 95% CI -0.09; 0.02%) and with a decreased risk for brain infarcts (RR = 0.91, 95% CI: 0.82-1.02). No association was found with smaller WML volume (B = -0.02% of ICV; 95% CI -0.07; 0.04%). No associations with change in brain structures over time were observed. Also, no associations between physical activity and cognitive performance or cognitive decline were found. These data suggest that leisure time physical activity does not have a significant contribution in preventing or slowing down brain abnormalities and cognitive decline in this cohort of middle-aged individuals already burdened with vascular disease. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  13. Brain Basics

    Medline Plus

    Full Text Available ... go awry, leading to mental illnesses. Brain Basics will introduce you to some of this science, such ... released it increases the chance that the neuron will fire. This enhances the electrical flow among brain ...

  14. Brain Basics

    Medline Plus

    Full Text Available ... than ever before. Brain Imaging Using brain imaging technologies such as magnetic resonance imaging (MRI), which uses ... the body's response to stress. impulse —An electrical communication signal sent between neurons by which neurons communicate ...

  15. Brain Basics

    Medline Plus

    Full Text Available ... mainly involved in controlling movement and aiding the flow of information to the front of the brain, ... the neuron will fire. This enhances the electrical flow among brain cells required for normal function and ...

  16. Brain Basics

    Medline Plus

    Full Text Available ... control specific body functions such as sleep and speech. The brain continues maturing well into a person's ... as in areas of the brain that control movement. When electrical signals are abnormal, they can cause ...

  17. Brain Basics

    Medline Plus

    Full Text Available ... it increases the chance that the neuron will fire. This enhances the electrical flow among brain cells ... This area of the brain also helps to control the amygdala during stressful events. Some research shows ...

  18. Brain Basics

    Medline Plus

    Full Text Available ... the brain How different parts of the brain communicate and work with each other How changes in ... occur when this process does not work correctly. Communication between neurons can also be electrical, such as ...

  19. Brain-derived neurotrophic factor is produced by skeletal muscle cells in response to contraction and enhances fat oxidation via activation of AMP-activated protein kinase

    DEFF Research Database (Denmark)

    Matthews, V B; Åström, Maj-Brit; Chan, M H S

    2009-01-01

    C12 skeletal muscle cells were electrically stimulated to mimic contraction. L6 myotubes and isolated rat extensor digitorum longus muscles were treated with BDNF and phosphorylation of the proteins AMP-activated protein kinase (AMPK) (Thr(172)) and acetyl coenzyme A carboxylase beta (ACCbeta) (Ser...... into the circulation. Bdnf mRNA and protein expression was increased in muscle cells that were electrically stimulated. BDNF increased phosphorylation of AMPK and ACCbeta and enhanced FAO both in vitro and ex vivo. The effect of BDNF on FAO was AMPK-dependent, since the increase in FAO was abrogated in cells infected......AIMS/HYPOTHESIS: Brain-derived neurotrophic factor (BDNF) is produced in skeletal muscle, but its functional significance is unknown. We aimed to determine the signalling processes and metabolic actions of BDNF. METHODS: We first examined whether exercise induced BDNF expression in humans. Next, C2...

  20. Brain-computer interface driven functional electrical stimulation system for overground walking in spinal cord injury participant.

    Science.gov (United States)

    King, Christine E; Wang, Po T; McCrimmon, Colin M; Chou, Cathy C Y; Do, An H; Nenadic, Zoran

    2014-01-01

    The current treatment for ambulation after spinal cord injury (SCI) is to substitute the lost behavior with a wheelchair; however, this can result in many co-morbidities. Thus, novel solutions for the restoration of walking, such as brain-computer interfaces (BCI) and functional electrical stimulation (FES) devices, have been sought. This study reports on the first electroencephalogram (EEG) based BCI-FES system for overground walking, and its performance assessment in an individual with paraplegia due to SCI. The results revealed that the participant was able to purposefully operate the system continuously in real time. If tested in a larger population of SCI individuals, this system may pave the way for the restoration of overground walking after SCI.

  1. What makes your brain suggestible? Hypnotizability is associated with differential brain activity during attention outside hypnosis.

    Science.gov (United States)

    Cojan, Yann; Piguet, Camille; Vuilleumier, Patrik

    2015-08-15

    Theoretical models of hypnosis have emphasized the importance of attentional processes in accounting for hypnotic phenomena but their exact nature and brain substrates remain unresolved. Individuals vary in their susceptibility to hypnosis, a variability often attributed to differences in attentional functioning such as greater ability to filter irrelevant information and inhibit prepotent responses. However, behavioral studies of attentional performance outside the hypnotic state have provided conflicting results. We used fMRI to investigate the recruitment of attentional networks during a modified flanker task in High and Low hypnotizable participants. The task was performed in a normal (no hypnotized) state. While behavioral performance did not reliably differ between groups, components of the fronto-parietal executive network implicated in monitoring (anterior cingulate cortex; ACC), adjustment (lateral prefrontal cortex; latPFC), and implementation of attentional control (intraparietal sulcus; IPS) were differently activated depending on the hypnotizability of the subjects: the right inferior frontal gyrus (rIFG) was more recruited, whereas IPS and ACC were less recruited by High susceptible individuals compared to Low. Our results demonstrate that susceptibility to hypnosis is associated with particular executive control capabilities allowing efficient attentional focusing, and point to specific neural substrates in right prefrontal cortex. We demonstrated that outside hypnosis, low hypnotizable subjects recruited more parietal cortex and anterior cingulate regions during selective attention conditions suggesting a better detection and implementation of conflict. However, outside hypnosis the right inferior frontal gyrus (rIFG) was more recruited by highly hypnotizable subjects during selective attention conditions suggesting a better control of conflict. Furthermore, in highly hypnotizable subjects this region was more connected to the default mode network

  2. The use of dendrograms to describe the electrical activity of motoneurons underlying behaviors in leeches

    Directory of Open Access Journals (Sweden)

    León Jacobo Juárez-Hernández

    2013-09-01

    Full Text Available The present manuscript aims at identifying patterns of electrical activity recorded from neurons of the leech nervous system, characterizing specific behaviors. When leeches are at rest, the electrical activity of neurons and motoneurons is poorly correlated. When leeches move their head and/or tail, in contrast, action potential (AP firing becomes highly correlated. When the head or tail suckers detach, specific patterns of electrical activity are detected. During elongation and contraction the electrical activity of motoneurons in the Medial Anterior and Dorsal Posterior nerves increase respectively and several motoneurons are activated both during elongation and contraction. During crawling, swimming and pseudo-swimming patterns of electrical activity are better described by the dendrograms of cross-correlations of motoneurons pairs. Dendrograms obtained from different animals exhibiting the same behavior are similar and by averaging these dendrograms we obtained a template underlying a given behavior. By using this template, the corresponding behavior is reliably identified from the recorded electrical activity. The analysis of dendrograms during different leech behavior reveals the fine orchestration of motoneurons firing specific to each stereotyped behavior. Therefore, dendrograms capture the subtle changes in the correlation pattern of neuronal networks when they become involved in different tasks or functions.

  3. Evaluation of the electric field in the brain during transcranial direct current stimulation: A sensitivity analysis.

    Science.gov (United States)

    Santos, Laura; Martinho, Miguel; Salvador, Ricardo; Wenger, Cornelia; Fernandes, Sofia R; Ripolles, Oscar; Ruffini, Giulio; Miranda, Pedro C

    2016-08-01

    The use of computational modeling studies accounts currently for the best approach to predict the electric field (E-field) distribution in transcranial direct current stimulation. As with any model, the values attributed to the physical properties, namely the electrical conductivity of the tissues, affect the predicted E-field distribution. A wide range of values for the conductivity of most tissues is reported in the literature. In this work, we used the finite element method to compute the E-field induced in a realistic human head model for two electrode montages targeting the left dorso-lateral prefrontal cortex (DLPFC). A systematic analysis of the effect of different isotropic conductivity profiles on the E-field distribution was performed for the standard bipolar 7×5 cm2 electrodes configuration and also for an optimized multielectrode montage. Average values of the E-field's magnitude, normal and tangential components were calculated in the target region in the left DLPFC. Results show that the field decreases with increasing scalp, cerebrospinal fluid (CSF) and grey matter (GM) conductivities, while the opposite is observed for the skull and white matter conductivities. The tissues whose conductivity most affects the E-field in the cortex are the scalp and the CSF, followed by the GM and the skull. Uncertainties in the conductivity of individual tissues may affect electric field values by up to about 80%.

  4. Synaptic Effects of Electric Fields

    Science.gov (United States)

    Rahman, Asif

    Learning and sensory processing in the brain relies on the effective transmission of information across synapses. The strength and efficacy of synaptic transmission is modifiable through training and can be modulated with noninvasive electrical brain stimulation. Transcranial electrical stimulation (TES), specifically, induces weak intensity and spatially diffuse electric fields in the brain. Despite being weak, electric fields modulate spiking probability and the efficacy of synaptic transmission. These effects critically depend on the direction of the electric field relative to the orientation of the neuron and on the level of endogenous synaptic activity. TES has been used to modulate a wide range of neuropsychiatric indications, for various rehabilitation applications, and cognitive performance in diverse tasks. How can a weak and diffuse electric field, which simultaneously polarizes neurons across the brain, have precise changes in brain function? Designing therapies to maximize desired outcomes and minimize undesired effects presents a challenging problem. A series of experiments and computational models are used to define the anatomical and functional factors leading to specificity of TES. Anatomical specificity derives from guiding current to targeted brain structures and taking advantage of the direction-sensitivity of neurons with respect to the electric field. Functional specificity originates from preferential modulation of neuronal networks that are already active. Diffuse electric fields may recruit connected brain networks involved in a training task and promote plasticity along active synaptic pathways. In vitro, electric fields boost endogenous synaptic plasticity and raise the ceiling for synaptic learning with repeated stimulation sessions. Synapses undergoing strong plasticity are preferentially modulated over weak synapses. Therefore, active circuits that are involved in a task could be more susceptible to stimulation than inactive circuits

  5. Whole-brain mapping of neuronal activity in the learned helplessness model of depression

    Directory of Open Access Journals (Sweden)

    Yongsoo eKim

    2016-02-01

    Full Text Available Some individuals are resilient, whereas others succumb to despair in repeated stressful situations. The neurobiological mechanisms underlying such divergent behavioral responses remain unclear. Here, we employed an automated method for mapping neuronal activity in search of signatures of stress responses in the entire mouse brain. We used serial two-photon tomography to detect expression of c-FosGFP – a marker of neuronal activation – in c-fosGFP transgenic mice subjected to the learned helplessness (LH procedure, a widely used model of stress-induced depression-like phenotype in laboratory animals. We found that mice showing helpless behavior had an overall brain-wide reduction in the level of neuronal activation compared with mice showing resilient behavior, with the exception of a few brain areas, including the locus coeruleus, that were more activated in the helpless mice. In addition, the helpless mice showed a strong trend of having higher similarity in whole brain activity profile among individuals, suggesting that helplessness is represented by a more stereotypic brain-wide activation pattern. This latter effect was confirmed in rats subjected to the LH procedure, using 2-deoxy-2[18F]fluoro-D-glucose positron emission tomography to assess neural activity. Our findings reveal distinct brain activity markings that correlate with adaptive and maladaptive behavioral responses to stress, and provide a framework for further studies investigating the contribution of specific brain regions to maladaptive stress responses.

  6. Moving the brain: Neuroimaging motivational changes of deep brain stimulation in obsessive-compulsive disorder

    NARCIS (Netherlands)

    Figee, M.

    2013-01-01

    Deep brain stimulation (DBS) is a neurosurgical technique that involves the implantation of electrodes in the brain. DBS enables electrical modulation of abnormal brain activity for treatment of neuropsychiatric disorders such as obsessive-compulsive disorder (OCD). Mrs. D. has been suffering from

  7. Brain Basics

    Medline Plus

    Full Text Available ... illnesses, such as depression, can occur when this process does not work correctly. Communication between neurons can also be electrical, such as in areas of the brain that control movement. When electrical signals are abnormal, they can ...

  8. Brain Basics

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    Full Text Available ... neuron's point of contact for receiving chemical and electrical signals called impulses from neighboring neurons. Axon which ... from one neuron to another as chemical or electrical signals. The brain begins as a small group ...

  9. Brain Basics

    Medline Plus

    Full Text Available ... Brain Neurotransmitters Everything we do relies on neurons communicating with one another. Electrical impulses and chemical signals ... depression, can occur when this process does not work correctly. Communication between neurons can also be electrical, ...

  10. ASPM regulates Wnt signaling pathway activity in the developing brain

    National Research Council Canada - National Science Library

    Buchman, Joshua J; Durak, Omer; Tsai, Li-Huei

    2011-01-01

    .... Mutations in Abnormal Spindle Microcephaly (ASPM) are the most common cause of MCPH. Here, we investigate the underlying functions of Aspm in brain development and find that Aspm expression is critical for proper neurogenesis and neuronal migration...

  11. Can transcranial electrical stimulation improve learning difficulties in atypical brain development? A future possibility for cognitive training.

    Science.gov (United States)

    Krause, Beatrix; Cohen Kadosh, Roi

    2013-10-01

    Learning difficulties in atypical brain development represent serious obstacles to an individual's future achievements and can have broad societal consequences. Cognitive training can improve learning impairments only to a certain degree. Recent evidence from normal and clinical adult populations suggests that transcranial electrical stimulation (TES), a portable, painless, inexpensive, and relatively safe neuroenhancement tool, applied in conjunction with cognitive training can enhance cognitive intervention outcomes. This includes, for instance, numerical processing, language skills and response inhibition deficits commonly associated with profound learning difficulties and attention-deficit hyperactivity disorder (ADHD). The current review introduces the functional principles, current applications and promising results, and potential pitfalls of TES. Unfortunately, research in child populations is limited at present. We suggest that TES has considerable promise as a tool for increasing neuroplasticity in atypically developing children and may be an effective adjunct to cognitive training in clinical settings if it proves safe. The efficacy and both short- and long-term effects of TES on the developing brain need to be critically assessed before it can be recommended for clinical settings. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

  12. Electrically and Hybrid-Induced Muscle Activations: Effects of Muscle Size and Fiber Type.

    Science.gov (United States)

    Stratton, Kelly; Faghri, Pouran D

    2016-06-13

    The effect of three electrical stimulation (ES) frequencies (10, 35, and 50 Hz) on two muscle groups with different proportions of fast and slow twitch fibers (abductor pollicis brevis (APB) and vastus lateralis (VL)) was explored. We evaluated the acute muscles' responses individually and during hybrid activations (ES superimposed by voluntary activations). Surface electromyography (sEMG) and force measurements were evaluated as outcomes. Ten healthy adults (mean age: 24.4 ± 2.5 years) participated after signing an informed consent form approved by the university Institutional Review Board. Protocols were developed to: 1) compare EMG activities during each frequency for each muscle when generating 25% Maximum Voluntary Contraction (MVC) force, and 2) compare EMG activities during each frequency when additional voluntary activation was superimposed over ES-induced 25% MVC to reach 50% and 75% MVC. Empirical mode decomposition (EMD) was utilized to separate ES artifacts from voluntary muscle activation. For both muscles, higher stimulation frequency (35 and 50Hz) induced higher electrical output detected at 25% of MVC, suggesting more recruitment with higher frequencies. Hybrid activation generated proportionally less electrical activity than ES alone. ES and voluntary activations appear to generate two different modes of muscle recruitment. ES may provoke muscle strength by activating more fatiguing fast acting fibers, but voluntary activation elicits more muscle coordination. Therefore, during the hybrid activation, less electrical activity may be detected due to recruitment of more fatigue-resistant deeper muscle fibers, not reachable by surface EMG.

  13. Electrically and hybrid-induced muscle activations: effects of muscle size and fiber type

    Directory of Open Access Journals (Sweden)

    Kelly Stratton

    2016-07-01

    Full Text Available The effect of three electrical stimulation (ES frequencies (10, 35, and 50 Hz on two muscle groups with different proportions of fast and slow twitch fibers (abductor pollicis brevis (APB and vastus lateralis (VL was explored. We evaluated the acute muscles’ responses individually and during hybrid activations (ES superimposed by voluntary activations. Surface electromyography (sEMG and force measurements were evaluated as outcomes. Ten healthy adults (mean age: 24.4 ± 2.5 years participated after signing an informed consent form approved by the university Institutional Review Board. Protocols were developed to: 1 compare EMG activities during each frequency for each muscle when generating 25% Maximum Voluntary Contraction (MVC force, and 2 compare EMG activities during each frequency when additional voluntary activation was superimposed over ES-induced 25% MVC to reach 50% and 75% MVC. Empirical mode decomposition (EMD was utilized to separate ES artifacts from voluntary muscle activation. For both muscles, higher stimulation frequency (35 and 50Hz induced higher electrical output detected at 25% of MVC, suggesting more recruitment with higher frequencies. Hybrid activation generated proportionally less electrical activity than ES alone. ES and voluntary activations appear to generate two different modes of muscle recruitment. ES may provoke muscle strength by activating more fatiguing fast acting fibers, but voluntary activation elicits more muscle coordination. Therefore, during the hybrid activation, less electrical activity may be detected due to recruitment of more fatigue-resistant deeper muscle fibers, not reachable by surface EMG.

  14. Kurt Lewin, psychological constructs and sources of brain cognitive activity

    OpenAIRE

    Duch, Włodzisław

    2017-01-01

    Understanding mind-brain-environment relations is one of the key topics in psychology. Kurt Lewin, inspired by theoretical physics, tried to establish topological and vector psychology analyzing patterns of interaction between the individual and her/his environment. The time is ripe to reformulate his ambitious goals, searching for ways to interpret objectively measured brain processes in terms of suitable psychological constructs. Connecting cognitive and social psychology constructs to neur...

  15. Test-retest reliability of fMRI brain activity during memory-encoding

    Directory of Open Access Journals (Sweden)

    David J Brandt

    2013-12-01

    Full Text Available The mechanisms underlying hemispheric specialization of memory are not completely understood. Functional magnetic resonance imaging (fMRI can be used to develop and test models of hemispheric specialization. In particular for memory tasks however, the interpretation of fMRI results is often hampered by the low reliability of the data. In the present study we therefore analyzed the test-retest reliability of fMRI brain activation related to an implicit memory encoding task, with a particular focus on brain activity of the medial temporal lobe (MTL. Fifteen healthy subjects were scanned with fMRI on two sessions (average retest interval 35 days using a commonly applied novelty encoding paradigm contrasting known and unknown stimuli. To assess brain lateralization, we used three different stimuli classes that differed in their verbalizability (words, scenes, fractals. Test-retest reliability of fMRI brain activation was assessed by an intraclass-correlation coefficient (ICC, describing the stability of inter-individual differences in the brain activation magnitude over time. We found as expected a left-lateralized brain activation network for the words paradigm, a bilateral network for the scenes paradigm, and predominantly right-hemispheric brain activation for the fractals paradigm. Although these networks were consistently activated in both sessions on the group level, across-subject reliabilities were only poor to fair (ICCs ≤ 0.45. Overall, the highest ICC values were obtained for the scenes paradigm, but only in strongly activated brain regions. In particular the reliability of brain activity of the MTL was poor for all paradigms. In conclusion, for novelty encoding paradigms the interpretation of fMRI results on a single subject level is hampered by its low reliability. More studies are needed to optimize the retest reliability of fMRI activation for memory tasks.

  16. Electrical brain responses in language-impaired children reveal grammar-specific deficits.

    Directory of Open Access Journals (Sweden)

    Elisabeth Fonteneau

    2008-03-01

    Full Text Available Scientific and public fascination with human language have included intensive scrutiny of language disorders as a new window onto the biological foundations of language and its evolutionary origins. Specific language impairment (SLI, which affects over 7% of children, is one such disorder. SLI has received robust scientific attention, in part because of its recent linkage to a specific gene and loci on chromosomes and in part because of the prevailing question regarding the scope of its language impairment: Does the disorder impact the general ability to segment and process language or a specific ability to compute grammar? Here we provide novel electrophysiological data showing a domain-specific deficit within the grammar of language that has been hitherto undetectable through behavioural data alone.We presented participants with Grammatical(G-SLI, age-matched controls, and younger child and adult controls, with questions containing syntactic violations and sentences containing semantic violations. Electrophysiological brain responses revealed a selective impairment to only neural circuitry that is specific to grammatical processing in G-SLI. Furthermore, the participants with G-SLI appeared to be partially compensating for their syntactic deficit by using neural circuitry associated with semantic processing and all non-grammar-specific and low-level auditory neural responses were normal.The findings indicate that grammatical neural circuitry underlying language is a developmentally unique system in the functional architecture of the brain, and this complex higher cognitive system can be selectively impaired. The findings advance fundamental understanding about how cognitive systems develop and all human language is represented and processed in the brain.

  17. Natural optical activity and its control by electric field in electrotoroidic systems

    Science.gov (United States)

    Prosandeev, Sergey; Malashevich, Andrei; Gui, Zhigang; Louis, Lydie; Walter, Raymond; Souza, Ivo; Bellaiche, L.

    2013-05-01

    We propose the existence, via analytical derivations, novel phenomenologies, and first-principles-based simulations, of a class of materials that are not only spontaneously optically active, but also for which the sense of rotation can be switched by an electric field applied to them via an induced transition between the dextrorotatory and laevorotatory forms. Such systems possess electric vortices that are coupled to a spontaneous electrical polarization. Furthermore, our atomistic simulations provide a deep microscopic insight into, and understanding of, this class of naturally optically active materials.

  18. Activated Brain Endothelial Cells Cross-Present Malaria Antigen.

    Science.gov (United States)

    Howland, Shanshan W; Poh, Chek Meng; Rénia, Laurent

    2015-06-01

    In the murine model of cerebral malaria caused by P. berghei ANKA (PbA), parasite-specific CD8+ T cells directly induce pathology and have long been hypothesized to kill brain endothelial cells that have internalized PbA antigen. We previously reported that brain microvessel fragments from infected mice cross-present PbA epitopes, using reporter cells transduced with epitope-specific T cell receptors. Here, we confirm that endothelial cells are the population responsible for cross-presentation in vivo, not pericytes or microglia. PbA antigen cross-presentation by primary brain endothelial cells in vitro confers susceptibility to killing by CD8+ T cells from infected mice. IFNγ stimulation is required for brain endothelial cross-presentation in vivo and in vitro, which occurs by a proteasome- and TAP-dependent mechanism. Parasite strains that do not induce cerebral malaria were phagocytosed and cross-presented less efficiently than PbA in vitro. The main source of antigen appears to be free merozoites, which were avidly phagocytosed. A human brain endothelial cell line also phagocytosed P. falciparum merozoites. Besides being the first demonstration of cross-presentation by brain endothelial cells, our results suggest that interfering with merozoite phagocytosis or antigen processing may be effective strategies for cerebral malaria intervention.

  19. Activated Brain Endothelial Cells Cross-Present Malaria Antigen.

    Directory of Open Access Journals (Sweden)

    Shanshan W Howland

    2015-06-01

    Full Text Available In the murine model of cerebral malaria caused by P. berghei ANKA (PbA, parasite-specific CD8+ T cells directly induce pathology and have long been hypothesized to kill brain endothelial cells that have internalized PbA antigen. We previously reported that brain microvessel fragments from infected mice cross-present PbA epitopes, using reporter cells transduced with epitope-specific T cell receptors. Here, we confirm that endothelial cells are the population responsible for cross-presentation in vivo, not pericytes or microglia. PbA antigen cross-presentation by primary brain endothelial cells in vitro confers susceptibility to killing by CD8+ T cells from infected mice. IFNγ stimulation is required for brain endothelial cross-presentation in vivo and in vitro, which occurs by a proteasome- and TAP-dependent mechanism. Parasite strains that do not induce cerebral malaria were phagocytosed and cross-presented less efficiently than PbA in vitro. The main source of antigen appears to be free merozoites, which were avidly phagocytosed. A human brain endothelial cell line also phagocytosed P. falciparum merozoites. Besides being the first demonstration of cross-presentation by brain endothelial cells, our results suggest that interfering with merozoite phagocytosis or antigen processing may be effective strategies for cerebral malaria intervention.

  20. Activated Brain Endothelial Cells Cross-Present Malaria Antigen

    Science.gov (United States)

    Howland, Shanshan W.; Poh, Chek Meng; Rénia, Laurent

    2015-01-01

    In the murine model of cerebral malaria caused by P. berghei ANKA (PbA), parasite-specific CD8+ T cells directly induce pathology and have long been hypothesized to kill brain endothelial cells that have internalized PbA antigen. We previously reported that brain microvessel fragments from infected mice cross-present PbA epitopes, using reporter cells transduced with epitope-specific T cell receptors. Here, we confirm that endothelial cells are the population responsible for cross-presentation in vivo, not pericytes or microglia. PbA antigen cross-presentation by primary brain endothelial cells in vitro confers susceptibility to killing by CD8+ T cells from infected mice. IFNγ stimulation is required for brain endothelial cross-presentation in vivo and in vitro, which occurs by a proteasome- and TAP-dependent mechanism. Parasite strains that do not induce cerebral malaria were phagocytosed and cross-presented less efficiently than PbA in vitro. The main source of antigen appears to be free merozoites, which were avidly phagocytosed. A human brain endothelial cell line also phagocytosed P. falciparum merozoites. Besides being the first demonstration of cross-presentation by brain endothelial cells, our results suggest that interfering with merozoite phagocytosis or antigen processing may be effective strategies for cerebral malaria intervention. PMID:26046849

  1. Learned EEG-based regulation of motor-related brain oscillations during application of transcranial electric currents: feasibility and limitations

    Directory of Open Access Journals (Sweden)

    Surjo R Soekadar

    2014-03-01

    Full Text Available Objective: Transcranial direct current stimulation (tDCS improves motor learning and can influence emotional processing or attention. However, it remained unclear whether learned electroencephalography (EEG-based brain-machine interface (BMI control during tDCS is feasible and how application of transcranial electric currents during BMI control would interfere with feature-extraction of physiological brain signals. Here we tested this combination and evaluated stimulation-dependent artifacts across different EEG frequencies and stability of motor imagery-based BMI control. Approach: Ten healthy volunteers were invited to two BMI-sessions, each comprising two 60-trial blocks. During the trials, modulation of mu-rhythms (8-15Hz associated with motor imagery recorded over C4 was translated into online cursor movements on a computer screen. During block 2, either sham (session A or anodal tDCS (session B was applied at 1mA with the stimulation electrode placed 1cm anterior of C4. Main results: tDCS was associated with a significant signal power increase in the lower frequencies most evident in the signal spectrum of the EEG channel closest to the stimulation electrode. Stimulation-dependent signal power increase exhibited a decay of 12dB per decade, leaving frequencies above 9Hz unaffected. Analysis of BMI control performance did not indicate a difference between blocks and tDCS conditions. Conclusion: Application of tDCS during learned EEG-based self-regulation of brain oscillations above 9Hz is feasible and safe, and might improve applicability of BMI systems in patient populations.

  2. Phasic and sustained fear in humans elicits distinct patterns of brain activity.

    Science.gov (United States)

    Alvarez, Ruben P; Chen, Gang; Bodurka, Jerzy; Kaplan, Raphael; Grillon, Christian

    2011-03-01

    Aversive events are typically more debilitating when they occur unpredictably than predictably. Studies in humans and animals indicate that predictable and unpredictable aversive events can induce phasic and sustained fear, respectively. Research in rodents suggests that anatomically related but distinct neural circuits may mediate phasic and sustained fear. We explored this issue in humans by examining threat predictability in three virtual reality contexts, one in which electric shocks were predictably signaled by a cue, a second in which shocks occurred unpredictably but never paired with a cue, and a third in which no shocks were delivered. Evidence of threat-induced phasic and sustained fear was presented using fear ratings and skin conductance. Utilizing recent advances in functional magnetic resonance imaging (fMRI), we were able to conduct whole-brain fMRI at relatively high spatial resolution and still have enough sensitivity to detect transient and sustained signal changes in the basal forebrain. We found that both predictable and unpredictable threat evoked transient activity in the dorsal amygdala, but that only unpredictable threat produced sustained activity in a forebrain region corresponding to the bed nucleus of the stria terminalis complex. Consistent with animal models hypothesizing a role for the cortex in generating sustained fear, sustained signal increases to unpredictable threat were also found in anterior insula and a frontoparietal cortical network associated with hypervigilance. In addition, unpredictable threat led to transient activity in the ventral amygdala-hippocampal area and pregenual anterior cingulate cortex, as well as transient activation and subsequent deactivation of subgenual anterior cingulate cortex, limbic structures that have been implicated in the regulation of emotional behavior and stress responses. In line with basic findings in rodents, these results provide evidence that phasic and sustained fear in humans may

  3. Brain activity during driving with distraction: an immersive fMRI study

    Directory of Open Access Journals (Sweden)

    Tom A Schweizer

    2013-02-01

    Full Text Available Introduction: Non-invasive measurements of brain activity have an important role to play in understanding driving ability. The current study aimed to identify the neural underpinnings of human driving behavior by visualizing the areas of the brain involved in driving under different levels of demand, such as driving while distracted or making left turns at busy intersections. Methods: To capture brain activity during driving, we placed a driving simulator with a fully functional steering wheel and pedals in a 3.0 Tesla functional magnetic resonance imaging (fMRI system. To identify the brain areas involved while performing different real-world driving maneuvers, participants completed tasks ranging from simple (right turns to more complex (left turns at busy intersections. To assess the effects of driving while distracted, participants were asked to perform an auditory task while driving analogous to speaking on a hands-free device and driving. Results: A widely distributed brain network was identified, especially when making left turns at busy intersections compared to more simple driving tasks. During distracted driving, brain activation shifted dramatically from the posterior, visual and spatial areas to the prefrontal cortex. Conclusions: Our findings suggest that the distracted brain sacrificed areas in the posterior brain important for visual attention and alertness to recruit enough brain resources to perform a secondary, cognitive task. The present findings offer important new insights into the scientific understanding of the neuro-cognitive mechanisms of driving behavior and lay down an important foundation for future clinical research.

  4. Distinct patterns of brain activity characterise lexical activation and competition in spoken word production.

    Directory of Open Access Journals (Sweden)

    Vitória Piai

    Full Text Available According to a prominent theory of language production, concepts activate multiple associated words in memory, which enter into competition for selection. However, only a few electrophysiological studies have identified brain responses reflecting competition. Here, we report a magnetoencephalography study in which the activation of competing words was manipulated by presenting pictures (e.g., dog with distractor words. The distractor and picture name were semantically related (cat, unrelated (pin, or identical (dog. Related distractors are stronger competitors to the picture name because they receive additional activation from the picture relative to other distractors. Picture naming times were longer with related than unrelated and identical distractors. Phase-locked and non-phase-locked activity were distinct but temporally related. Phase-locked activity in left temporal cortex, peaking at 400 ms, was larger on unrelated than related and identical trials, suggesting differential activation of alternative words by the picture-word stimuli. Non-phase-locked activity between roughly 350-650 ms (4-10 Hz in left superior frontal gyrus was larger on related than unrelated and identical trials, suggesting differential resolution of the competition among the alternatives, as reflected in the naming times. These findings characterise distinct patterns of activity associated with lexical activation and competition, supporting the theory that words are selected by competition.

  5. Feasibility assessment for battery electric vehicles based on multi-day activity-travel patterns.

    Science.gov (United States)

    2017-04-11

    A Battery Electric Vehicle (BEV) feasibility considering State Of Charge (SOC) level is : assessed using multiday activity-travel patterns to overcome the limitations of using one-day : activity-travel patterns. Since multi-day activity-travel patter...

  6. Brain plasticity after implanted peroneal nerve electrical stimulation to improve gait in chronic stroke patients: Two case reports.

    Science.gov (United States)

    Thibaut, Aurore; Moissenet, Florent; Di Perri, Carol; Schreiber, Céline; Remacle, Angélique; Kolanowski, Elisabeth; Chantraine, Frédéric; Bernard, Claire; Hustinx, Roland; Tshibanda, Jean-Flory; Filipetti, Paul; Laureys, Steven; Gosseries, Olivia

    2017-01-01

    Recent studies have shown that stimulation of the peroneal nerve using an implantable 4-channel peroneal nerve stimulator could improve gait in stroke patients. To assess structural cortical and regional cerebral metabolism changes associated with an implanted peroneal nerve electrical stimulator to correct foot drop related to a central nervous system lesion. Two stroke patients presenting a foot drop related to a central nervous system lesion were implanted with an implanted peroneal nerve electrical stimulator. Both patients underwent clinical evaluations before implantation and one year after the activation of the stimulator. Structural magnetic resonance imaging (MRI) and [18F]-fluorodeoxyglucose-positron emission tomography (FDG-PET) were acquired before and one year after the activation of the stimulator. Foot drop was corrected for both patients after the implantation of the stimulator. After one year of treatment, patient 1 improved in three major clinical tests, while patient 2 only improved in one test. Prior to treatment, FDG-PET showed a significant hypometabolism in premotor, primary and supplementary motor areas in both patients as compared to controls, with patient 2 presenting more widespread hypometabolism. One year after the activation of the stimulator, both patients showed significantly less hypometabolism in the damaged motor cortex. No difference was observed on the structural MRI. Clinical improvement of gait under peroneal nerve electrical stimulation in chronic stroke patients presenting foot drop was paralleled to metabolic changes in the damaged motor cortex.

  7. The relation of ongoing brain activity, evoked neural responses, and cognition

    Directory of Open Access Journals (Sweden)

    Sepideh Sadaghiani

    2010-06-01

    Full Text Available Ongoing brain activity has been observed since the earliest neurophysiological recordings and is found over a wide range of temporal and spatial scales. It is characterized by remarkably large spontaneous modulations. Here, we review evidence for the functional role of these ongoing activity fluctuations and argue that they constitute an essential property of the neural architecture underlying cognition. The role of spontaneous activity fluctuations is probably best understood when considering both their spatiotemporal structure and their functional impact on cognition. We first briefly argue against a ‘segregationist’ view on ongoing activity, both in time and space, countering this view with an emphasis on integration within a hierarchical spatiotemporal organization of intrinsic activity. We then highlight the flexibility and context-sensitivity of intrinsic functional connectivity that suggest its involvement in functionally relevant information processing. This role in information processing is pursued by reviewing how ongoing brain activity interacts with afferent and efferent information exchange of the brain with its environment. We focus on the relationship between the variability of ongoing and evoked brain activity, and review recent reports that tie ongoing brain activity fluctuations to variability in human perception and behavior. Finally, these observations are discussed within the framework of the free-energy principle which – applied to human brain function - provides a theoretical account for a non-random, coordinated interaction of ongoing and evoked activity in perception and behaviour.

  8. Differential effect of spinal cord injury and functional impairment on human brain activation

    NARCIS (Netherlands)

    Curt, A; Bruehlmeier, M; Leenders, KL; Roelcke, U; Dietz, [No Value

    Reorganization of human brain function after spinal cord injury (SCI) has been shown in electrophysiological studies. However, it is less clear how far changes of brain activation in SCI patients are influenced by the extent of SCI (neuronal lesion) or the consequent functional impairment. Positron

  9. Alterations in brain activation during cholinergic enhancement with rivastigmine in Alzheimer's disease

    OpenAIRE

    Rombouts, S.; Barkhof, F; van Meel, C S; Scheltens, P

    2002-01-01

    Background: Rivastigmine enhances cholinergic activity and has been shown in clinical trials to decrease the rate of deterioration in Alzheimer's disease. It remains unclear where in the brain it exerts its effect. Functional magnetic resonance imaging (fMRI) can be used to measure changes in brain function and relate these to cognition.

  10. Physical activity, structural brain changes and cognitive decline. The SMART-MR study

    NARCIS (Netherlands)

    Kooistra, M.; Boss, H.M.; van der Graaf, Y.; Kappelle, L.J.; Biessels, G.J.; Geerlings, M.I.

    2014-01-01

    Objective: We aimed to examine the cross-sectional and prospective relationship between leisure time physical activity, brain MRI abnormalities and cognitive performance in patients with vascular disease. Methods: Within the SMART-MR study, 1.5T MRI of the brain and neuropsychological examinations

  11. How Curriculum Leaders Can Involve the Right Brain in Active Reading and Writing Development.

    Science.gov (United States)

    Sinatra, Richard; Stahl-Gemake, Josephine

    Curriculum leaders, program specialists, and teachers can intentionally arouse the activation of one hemisphere of the brain over the other through the use of right brain strategies in language learning. While most functions of the left hemisphere are concerned with convergent production (getting the right answer), functions of the right…

  12. Effect of hypnotic pain modulation on brain activity in patients with temporomandibular disorder pain

    DEFF Research Database (Denmark)

    Abrahamsen, Randi; Dietz, Martin; Lodahl, Sanne

    2010-01-01

    Hypnosis modulates pain perception but the associated brain mechanisms in chronic pain conditions are poorly understood. Brain activity evoked by painful repetitive pin-prick stimulation of the left mental nerve region was investigated with use of fMRI in 19 patients with painful temporomandibular...

  13. Modeling the dynamics of human brain activity with recurrent neural networks

    NARCIS (Netherlands)

    Güçlü, U.; Gerven, M.A.J. van

    2017-01-01

    Encoding models are used for predicting brain activity in response to sensory stimuli with the objective of elucidating how sensory information is represented in the brain. Encoding models typically comprise a nonlinear transformation of stimuli to features (feature model) and a linear convolution

  14. Brain activation during associative short-term memory maintenance is not predictive for subsequent retrieval

    NARCIS (Netherlands)

    Bergmann, H.C.; Daselaar, S.M.; Beul, S.F.; Rijpkema, M.J.P.; Fernandez, G.S.E.; Kessels, R.P.C.

    2015-01-01

    Performance on working memory (WM) tasks may partially be supported by long-term memory (LTM) processing. Hence, brain activation recently being implicated in WM may actually have been driven by (incidental) LTM formation. We examined which brain regions actually support successful WM processing,

  15. The Electrical Activity of Neurons Subject to Electromagnetic Induction and Gaussian White Noise

    Science.gov (United States)

    Wang, Ya; Ma, Jun; Xu, Ying; Wu, Fuqiang; Zhou, Ping

    Neurons can give appropriate response to external electrical stimuli and the modes in electrical activities can be carefully selected. Most of the neuron models mainly emphasize on the ion channel currents embedded into the membrane and the properties in electrical activities can be produced in the theoretical models. Indeed, some physical effect should be considered during the model setting for neuronal activities. In fact, induced current and the electrical field will cause the membrane potential to change and an exchange of charged ions during the fluctuation of ion concentration in cell. As a result, the effect of electromagnetic induction should be seriously considered. In this paper, magnetic flux is proposed to describe the effect of electromagnetic field, and the memristor is used to realize coupling on membrane by inputting induced current based on consensus of physical unit. Noise is also considered to detect the dynamical response in electrical activities and stochastic resonance, it is found that multiple modes can be selected in the electrical activities and it could be associated with memory effect and self-adaption in neurons.

  16. [Mechanical and electrical uterine activity. Part I. Contractions monitoring].

    Science.gov (United States)

    Zietek, Jerzy; Sikora, Jerzy; Horoba, Krzysztof; Matonia, Adam; Jezewski, Janusz; Magnucki, Jacek; Kobielska, Lucyna

    2008-11-01

    Correct uterine contraction activity during labour determines physiological fetal delivery and ensures its satisfactory outcome. Contraction activity monitoring may be accomplished by either recording of the mechanical properties of the uterine muscle and/or by measurement of the action potentials produced by the uterus during contraction. In the following paper, the current state of knowledge concerning the methods for assessment and monitoring of the uterine contraction activity was evaluated. The electrophysiological properties of the uterus were given. The mechanical methods of uterine activity monitoring: internal and external tocography were described. The development of the electrohysterography as the method providing the signal comprising complete information on bioelectrical properties of the uterine muscle was presented. The conclusion was that the analysis of the electrohysterogram enables a description of the source of the uterine contraction activity, whereas currently applied mechanical methods merely record the results of this activity.

  17. Human sexual behavior related to pathology and activity of the brain.

    Science.gov (United States)

    Komisaruk, Barry R; Rodriguez Del Cerro, Maria Cruz

    2015-01-01

    Reviewed in this chapter are: (1) correlations among human sexual behavior, brain pathology, and brain activity, including caveats regarding the interpretation of "cause and effect" among these factors, and the degree to which "hypersexuality" and reported changes in sexual orientation correlated with brain pathology are uniquely sexual or are attributable to a generalized disinhibition of brain function; (2) the effects, in some cases inhibitory, in others facilitatory, on sexual behavior and motivation, of stroke, epileptic seizures, traumatic brain injury, and brain surgery; and (3) insights into sexual motivation and behavior recently gained from functional brain imaging research and its interpretive limitations. We conclude from the reviewed research that the neural orchestra underlying the symphony of human sexuality comprises, rather than brain "centers," multiple integrated brain systems, and that there are more questions than answers in our understanding of the control of human sexual behavior by the brain - a level of understanding that is still in embryonic form. © 2015 Elsevier B.V. All rights reserved.

  18. N-3 fatty acids, neuronal activity and energy metabolism in the brain

    Directory of Open Access Journals (Sweden)

    Harbeby Emilie

    2012-07-01

    Full Text Available The content of docosahexaenoic acid (DHA in brain membranes is of crucial importance for the optimum development of brain functions. A lack of DHA accretion in the brain is accompanied by deficits in learning behavior linked to impairments in neurotransmission processes, which might result from alteration of brain fuel supply and hence energy metabolism. Experimental data we published support the hypothesis that n-3 fatty acids may modulate brain glucose utilization and metabolism. Indeed rats made deficient in DHA by severe depletion of total n-3 fatty acid intake have 1 a lower brain glucose utilization, 2 a decrease of the glucose transporter protein content GLUT1 both in endothelial cells and in astrocytes, 3 a repression of GLUT1 gene expression in basal state as well as upon neuronal activation. This could be due to the specific action of DHA on the regulation of GLUT1 expression since rat brain endothelial cells cultured with physiological doses of DHA had an increased GLUT1 protein content and glucose transport when compared to non-supplemented cells. These experimental data highlight the impact of n-3 fatty acids on the use of brain glucose, thereby constituting a key factor in the control of synaptic activity. This emerging role suggests that dietary intake of n-3 fatty acids can help to reduce the cognitive deficits in the elderly and possibly symptomatic cerebral metabolic alterations in Alzheimer disease by promoting brain glucose metabolism.

  19. The feasibility of a brain-computer interface functional electrical stimulation system for the restoration of overground walking after paraplegia.

    Science.gov (United States)

    King, Christine E; Wang, Po T; McCrimmon, Colin M; Chou, Cathy C Y; Do, An H; Nenadic, Zoran

    2015-09-24

    Direct brain control of overground walking in those with paraplegia due to spinal cord injury (SCI) has not been achieved. Invasive brain-computer interfaces (BCIs) may provide a permanent solution to this problem by directly linking the brain to lower extremity prostheses. To justify the pursuit of such invasive systems, the feasibility of BCI controlled overground walking should first be established in a noninvasive manner. To accomplish this goal, we developed an electroencephalogram (EEG)-based BCI to control a functional electrical stimulation (FES) system for overground walking and assessed its performance in an individual with paraplegia due to SCI. An individual with SCI (T6 AIS B) was recruited for the study and was trained to operate an EEG-based BCI system using an attempted walking/idling control strategy. He also underwent muscle reconditioning to facilitate standing and overground walking with a commercial FES system. Subsequently, the BCI and FES systems were integrated and the participant engaged in several real-time walking tests using the BCI-FES system. This was done in both a suspended, off-the-ground condition, and an overground walking condition. BCI states, gyroscope, laser distance meter, and video recording data were used to assess the BCI performance. During the course of 19 weeks, the participant performed 30 real-time, BCI-FES controlled overground walking tests, and demonstrated the ability to purposefully operate the BCI-FES system by following verbal cues. Based on the comparison between the ground truth and decoded BCI states, he achieved information transfer rates >3 bit/s and correlations >0.9. No adverse events directly related to the study were observed. This proof-of-concept study demonstrates for the first time that restoring brain-controlled overground walking after paraplegia due to SCI is feasible. Further studies are warranted to establish the generalizability of these results in a population of individuals with paraplegia

  20. Relation Between EEG Activity and Brain Oxygenation in Preterm Neonates.

    Science.gov (United States)

    Caicedo, Alexander; Thewissen, Liesbeth; Smits, Anne; Naulaers, Gunnar; Allegaert, Karel; Van Huffel, Sabine

    2017-01-01

    This study investigates the relationship between brain oxygenation, assessed by means of near infrared spectroscopy (NIRS), and brain function, assessed by means of electroencephalography (EEG). Using NIRS signals measuring the regional cerebral oxygen saturation (rScO2) and computing the fractional tissue oxygen extraction (FTOE), we compared how these variables relate to different features extracted from the EEG, such as the inter-burst interval (IBI) duration and amplitude, the amplitude of the EEG, and the amplitude of the burst. A cohort of 22 neonates undergoing sedation by propofol was studied and a regression of the NIRS-derived values to the different EEG features was made. We found that higher values of FTOE were related to higher values of EEG amplitude. These results might be of used in the monitoring of proper brain function in neonates.

  1. The potential of multilateral analyses of neuronal activities in future brain-machine interface research.

    Science.gov (United States)

    Sakamoto, Kazuhiro

    2013-01-01

    Current brain-machine interfaces are based on the implicit assumption that information encoded by neuronal activities does not change despite some recent physiological studies indicating that information encoded by neuronal activities changes. Here, we highlight the necessity for advanced decoding of neuronal activities. Especially, we discuss the advantages of multilateral analyses of neuronal activities, including synchronization and variability.

  2. A reliability study on brain activation during active and passive arm movements supported by an MRI-compatible robot.

    Science.gov (United States)

    Estévez, Natalia; Yu, Ningbo; Brügger, Mike; Villiger, Michael; Hepp-Reymond, Marie-Claude; Riener, Robert; Kollias, Spyros

    2014-11-01

    In neurorehabilitation, longitudinal assessment of arm movement related brain function in patients with motor disability is challenging due to variability in task performance. MRI-compatible robots monitor and control task performance, yielding more reliable evaluation of brain function over time. The main goals of the present study were first to define the brain network activated while performing active and passive elbow movements with an MRI-compatible arm robot (MaRIA) in healthy subjects, and second to test the reproducibility of this activation over time. For the fMRI analysis two models were compared. In model 1 movement onset and duration were included, whereas in model 2 force and range of motion were added to the analysis. Reliability of brain activation was tested with several statistical approaches applied on individual and group activation maps and on summary statistics. The activated network included mainly the primary motor cortex, primary and secondary somatosensory cortex, superior and inferior parietal cortex, medial and lateral premotor regions, and subcortical structures. Reliability analyses revealed robust activation for active movements with both fMRI models and all the statistical methods used. Imposed passive movements also elicited mainly robust brain activation for individual and group activation maps, and reliability was improved by including additional force and range of motion using model 2. These findings demonstrate that the use of robotic devices, such as MaRIA, can be useful to reliably assess arm movement related brain activation in longitudinal studies and may contribute in studies evaluating therapies and brain plasticity following injury in the nervous system.

  3. Sexual dimorphism of brain aromatase activity in medaka: induction of a female phenotype by estradiol.

    Science.gov (United States)

    Melo, A C; Ramsdell, J S

    2001-01-01

    In this study we identified sex-dependent dimorphism of brain aromatase in the teleost medaka and examined its regulation by sex steriods. We first investigated differential distribution of brain aromatase activity in sexually mature male and female medaka in serial coronal sections of the brain and identified the hypothalamic nuclei contained in each section using the brain atlas of medaka. In the brain of male medaka, high levels of activity are localized in sections containing the preoptic (POA) and suprachiasmatic nuclei (SC) (63-75 fmol/hr) and low levels in the nuclei periventricular dorsalis (HD), ventralis (HV), and caudalis (Hc), nuclei diffusus of lobulus inferiores (NDIL), and nuclei tuberi anteriores (TA) and posteriores (TP) (< 25 fmol/hr). In the brain of female medaka high aromatase activity is localized in sections containing the HD, HV, Hc, NDIL, TA, and TP (85-80 fmol/hr) and highly variable levels in the POA and SC (23-70 fmol/hr). The concentration and time dependency of the exposure of male medaka to estradiol on the total brain aromatase activity and morphologic sex characteristics were determined next. Estradiol increased the activity of brain aromatase in a concentration-dependent manner at 2.5 and 25 microg/L, but the increase was lower at higher concentrations of the hormone. The effect was time dependent, gradually increasing up to the fifth day of exposure, after which it reached a plateau. Estradiol induction of brain aromatase analyzed using Lineweaver-Burke plots of saturation assays revealed a non-first-order reaction. The results indicate that a positive feedback mechanism regulates brain aromatase and imply that the sexual dimorphic distribution of aromatase may be highly sensitive to physiologic cues and environmental perturbations in fish. PMID:11333187

  4. The costs of a big brain: extreme encephalization results in higher energetic demand and reduced hypoxia tolerance in weakly electric African fishes.

    Science.gov (United States)

    Sukhum, Kimberley V; Freiler, Megan K; Wang, Robert; Carlson, Bruce A

    2016-12-28

    A large brain can offer several cognitive advantages. However, brain tissue has an especially high metabolic rate. Thus, evolving an enlarged brain requires either a decrease in other energetic requirements, or an increase in overall energy consumption. Previous studies have found conflicting evidence for these hypotheses, leaving the metabolic costs and constraints in the evolution of increased encephalization unclear. Mormyrid electric fishes have extreme encephalization comparable to that of primates. Here, we show that brain size varies widely among mormyrid species, and that there is little evidence for a trade-off with organ size, but instead a correlation between brain size and resting oxygen consumption rate. Additionally, we show that increased brain size correlates with decreased hypoxia tolerance. Our data thus provide a non-mammalian example of extreme encephalization that is accommodated by an increase in overall energy consumption. Previous studies have found energetic trade-offs with variation in brain size in taxa that have not experienced extreme encephalization comparable with that of primates and mormyrids. Therefore, we suggest that energetic trade-offs can only explain the evolution of moderate increases in brain size, and that the energetic requirements of extreme encephalization may necessitate increased overall energy investment. © 2016 The Author(s).

  5. PET study of brain maintenance of verbal creative activity.

    Science.gov (United States)

    Bechtereva, N P; Korotkov, A D; Pakhomov, S V; Roudas, M S; Starchenko, M G; Medvedev, S V

    2004-06-01

    This paper deals with the investigation of the brain organization of verbal creativity. Psychological tasks were designed in accordance with two main strategies used by volunteers in solving creative tasks. Regional cerebral blood flow (rCBF) was measured with positron emission tomography (PET) when performing two types of creative tasks in two groups of subjects, each type of the task organizing the creativity process in its own way. Valuable brain correlates of creativity were revealed in the left parieto-temporal regions (Brodmann areas 39 and 40). Copyright 2004 Elsevier B.V.

  6. Platelet activation using electric pulse stimulation: growth factor profile and clinical implications.

    Science.gov (United States)

    Torres, Andrew S; Caiafa, Antonio; Garner, Allen L; Klopman, Steve; LaPlante, Nicole; Morton, Christine; Conway, Kenneth; Michelson, Alan D; Frelinger, Andrew L; Neculaes, V Bogdan

    2014-09-01

    Autologous platelet gel therapy using platelet-rich plasma has emerged as a promising alternative for chronic wound healing, hemostasis, and wound infection control. A critical step for this therapeutic approach is platelet activation, typically performed using bovine thrombin (BT) and calcium chloride. However, exposure of humans to BT can stimulate antibody formation, potentially resulting in severe hemorrhagic or thrombotic complications. Electric pulse stimulation using nanosecond PEFs (pulse electric fields) is an alternative, nonbiochemical platelet activation method, thereby avoiding exposure to xenogeneic thrombin and associated risks. In this study, we identified specific requirements for a clinically relevant activator instrument by dynamically measuring current, voltage, and electric impedance for platelet-rich plasma samples. From these samples, we investigated the profile of growth factors released from human platelets with electric pulse stimulation versus BT, specifically platelet-derived growth factor, transforming growth factor β, and epidermal growth factor, using commercial enzyme-linked immunosorbent assay kits. Electric pulse stimulation triggers growth factor release from platelet α-granules at the same or higher level compared with BT. Electric pulse stimulation is a fast, inexpensive, easy-to-use platelet activation method for autologous platelet gel therapy.

  7. Epidermal electrode technology for detecting ultrasonic perturbation of sensory brain activity.

    Science.gov (United States)

    Huang, Stanley; Fisher, Jonathan A N; Ye, Meijun; Kim, Yun-Soung; Ma, Rui; Nabili, Marjan; Krauthamer, Victor; Myers, Matthew R; Coleman, Todd P; Welle, Cristin G

    2017-08-29

    We aim to demonstrate the in vivo capability of a wearable sensor technology to detect localized perturbations of sensory-evoked brain activity. Cortical somatosensory evoked potentials (SSEPs) were recorded in mice via wearable, flexible epidermal electrode arrays. We then utilized the sensors to explore the effects of transcranial focused ultrasound, which noninvasively induced neural perturbation. SSEPs recorded with flexible epidermal sensors were quantified and benchmarked against those recorded with invasive epidural electrodes. We found that cortical SSEPs recorded by flexible epidermal sensors were stimulus frequency-dependent. Immediately following controlled, focal ultrasound perturbation, the sensors detected significant SSEP modulation, which consisted of dynamic amplitude decreases and altered stimulus-frequency dependence. These modifications were also dependent on the ultrasound perturbation dosage. The effects were consistent with those recorded with invasive electrodes, albeit with roughly one order of magnitude lower signal-to-noise ratio. We found that flexible epidermal sensors reported multiple SSEP parameters that were sensitive to focused ultrasound. This work therefore (1) establishes that epidermal electrodes are appropriate for monitoring the integrity of major CNS functionalities through SSEP, and (2) leveraged this technology to explore ultrasound-induced neuromodulation. The sensor technology is well-suited for this application because the sensor electrical properties are uninfluenced by direct exposure to ultrasound irradiation. The sensors and experimental paradigm we present involve standard, safe clinical neurological assessment methods and are thus applicable to a wide range of future translational studies in humans with any manner of health condition.

  8. Photoacoustic imaging to detect rat brain activation after cocaine hydrochloride injection

    Science.gov (United States)

    Jo, Janggun; Yang, Xinmai

    2011-03-01

    Photoacoustic imaging (PAI) was employed to detect small animal brain activation after the administration of cocaine hydrochloride. Sprague Dawley rats were injected with different concentrations (2.5, 3.0, and 5.0 mg per kg body) of cocaine hydrochloride in saline solution through tail veins. The brain functional response to the injection was monitored by photoacoustic tomography (PAT) system with horizontal scanning of cerebral cortex of rat brain. Photoacoustic microscopy (PAM) was also used for coronal view images. The modified PAT system used multiple ultrasonic detectors to reduce the scanning time and maintain a good signal-to-noise ratio (SNR). The measured photoacoustic signal changes confirmed that cocaine hydrochloride injection excited high blood volume in brain. This result shows PAI can be used to monitor drug abuse-induced brain activation.

  9. Electrical conductivity images of active and fossil fault zones

    OpenAIRE

    Oliver Ritter; A. Hoffmann-Rothe; P. A. Bedrosian; Ute Weckmann; V. Haak;  ;  

    2005-01-01

    We compare recent magnetotelluric investigations of four large fault systems: (i) the actively deforming, ocean-continent interplate San Andreas Fault (SAF), (ii) the actively deforming, continent-continent interplate Dead Sea Transform (DST), (iii) the currently inactive, trench-linked intraplate West Fault (WF) in northern Chile, and (iv) the Waterberg Fault/Omaruru Lineament (WF/OL) in Namibia, a fossilized intraplate shear zone formed during early Proterozoic continental collision. These ...

  10. Working memory brain activity and capacity link MAOA polymorphism to aggressive behavior during development

    National Research Council Canada - National Science Library

    Ziermans, T; Dumontheil, I; Roggeman, C; Peyrard-Janvid, M; Matsson, H; Kere, J; Klingberg, T

    2012-01-01

    ...) capacity is a risk factor for developing psychopathology. Brain activity represents a promising endophenotype for linking genes to behavior and for improving our understanding of the neurobiology of WM development...

  11. Neuromagnetic brain activity associated with anticipatory postural adjustments for bimanual load lifting.

    Science.gov (United States)

    Ng, Tommy H B; Sowman, Paul F; Brock, Jon; Johnson, Blake W

    2013-02-01

    During bimanual load lifting, the brain must anticipate the effects of unloading upon the load-bearing arm. Little is currently known about the neural networks that coordinate these anticipatory postural adjustments. We measured neuromagnetic brain activity with whole-head magnetoencephalography while participants performed a bimanual load-lifting task. Anticipatory adjustments were associated with reduction in biceps brachii muscle activity of the load-bearing arm and pre-movement desynchronization of the cortical beta rhythm. Beamforming analyses localized anticipatory brain activity to the precentral gyrus, basal ganglia, supplementary motor area, and thalamus, contralateral to the load-bearing arm. To our knowledge this is the first human neuroimaging study to directly investigate anticipatory postural adjustments and to explicitly partition the anticipatory and volitional aspects of brain activity in bimanual load lifting. These data contribute to our understanding of the neural systems supporting anticipatory postural adjustments in healthy adults. Copyright © 2012 Elsevier Inc. All rights reserved.

  12. Brain activity during observation of actions. Influence of action content and subject's strategy

    National Research Council Canada - National Science Library

    Decety, J; Grèzes, J; Costes, N; Perani, D; Jeannerod, M; Procyk, E; Grassi, F; Fazio, F

    1997-01-01

    ...: to be able to recognize or to imitate them later. We found that differences in the meaning of the action, irrespective of the strategy used during observation, lead to different patterns of brain activity and clear left/right asymmetries...

  13. Effects of sports participation on psychiatric symptoms and brain activations during sports observation in schizophrenia

    National Research Council Canada - National Science Library

    Takahashi, H; Sassa, T; Shibuya, T; Kato, M; Koeda, M; Murai, T; Matsuura, M; Asai, K; Suhara, T; Okubo, Y

    2012-01-01

    .... However, the neurobiological basis for this remains poorly understood. We aimed to examine the effect of sports participation on weight gain, psychiatric symptoms and brain activation during sports observation in schizophrenia patients...

  14. Non-invasive electrical brain stimulation: from acute to late-stage treatment of central nervous system damage

    Directory of Open Access Journals (Sweden)

    Petra Henrich-Noack

    2017-01-01

    Full Text Available Non-invasive brain current stimulation (NIBS is a promising and versatile tool for inducing neuroplasticity, protection and functional rehabilitation of damaged neuronal systems. It is technically simple, requires no surgery, and has significant beneficial effects. However, there are various technical approaches for NIBS which influence neuronal networks in significantly different ways. Transcranial direct current stimulation (tDCS, alternating current stimulation (ACS and repetitive transcranial magnetic stimulation (rTMS all have been applied to modulate brain activity in animal experiments under normal and pathological conditions. Also clinical trials have shown that tDCS, rTMS and ACS induce significant behavioural effects and can – depending on the parameters chosen – enhance or decrease brain excitability and influence performance and learning as well as rehabilitation and protective mechanisms. The diverse phaenomena and partially opposing effects of NIBS are not yet fully understood and mechanisms of action need to be explored further in order to select appropriate parameters for a given task, such as current type and strength, timing, distribution of current densities and electrode position. In this review, we will discuss the various parameters which need to be considered when designing a NIBS protocol and will put them into context with the envisaged applications in experimental neurobiology and medicine such as vision restoration, motor rehabilitation and cognitive enhancement.

  15. Human brain activation during sexual stimulation of the penis

    NARCIS (Netherlands)

    Georgiadis, [No Value; Holstege, G; Georgiadis, Janniko R.

    2005-01-01

    Penile sensory information is essential for reproduction, but almost nothing is known about how sexually salient inputs from the penis are processed in the brain. We used positron emission tomography to measure regional cerebral blood flow (rCBF) during various stages of male sexual performance.

  16. Tasting calories differentially affects brain activation during hunger and satiety

    NARCIS (Netherlands)

    Rijn, van I.; Graaf, de C.; Smeets, P.A.M.

    2015-01-01

    An important function of eating is ingesting energy. Our objectives were to assess whether oral exposure to caloric and non-caloric stimuli elicits discriminable responses in the brain and to determine in how far these responses are modulated by hunger state and sweetness. Thirty women tasted three

  17. Tasting calories differentially affects brain activation during hunger and satiety

    NARCIS (Netherlands)

    van Rijn, Inge; de Graaf, Cees; Smeets, Paul A M|info:eu-repo/dai/nl/304817740

    2015-01-01

    Our objectives were to assess whether oral exposure to caloric and non-caloric stimuli elicits discriminable responses in the brain and to determine in how far these responses are modulated by hunger state and sweetness. Thirty women tasted three stimuli in two motivational states (hunger and

  18. Imaging brain tumor proliferative activity with [I-124]iododeoxyuridine

    NARCIS (Netherlands)

    Blasberg, RG; Roelcke, U; Weinreich, R; Beattie, B; von Ammon, K; Yonekawa, Y; Landolt, H; Guenther, [No Value; Crompton, NEA; Vontobel, P; Missimer, J; Maguire, RP; Koziorowski, J; Knust, EJ; Finn, RD; Leenders, KL

    2000-01-01

    Iododeoxyuridine (IUdR) uptake and retention was imaged by positron emission tomography (PET) at 0-48 min and 24 h after administration of 28.0-64.4 MBq (0.76-1.74 mCi) of [I-124]IUdR in 20 patients with brain tumors, including meningiomas and gliomas, The PET images were directly compared with

  19. Breastfeeding, Brain Activation to Own Infant Cry, and Maternal Sensitivity

    Science.gov (United States)

    Kim, Pilyoung; Feldman, Ruth; Mayes, Linda C.; Eicher, Virginia; Thompson, Nancy; Leckman, James F.; Swain, James E.

    2011-01-01

    Background: Research points to the importance of breastfeeding for promoting close mother-infant contact and social-emotional development. Recent functional magnetic resonance imaging (fMRI) studies have identified brain regions related to maternal behaviors. However, little research has addressed the neurobiological mechanisms underlying the…

  20. Preservation of electrocortical brain activity during hypoxemia in preterm lambs.

    NARCIS (Netherlands)

    Os, S.H.G. van; Klaessens, J.H.G.M.; Hopman, J.C.W.; Liem, D.; Bor, M. van de

    2003-01-01

    Adequate cerebral perfusion is necessary to preserve cerebral O(2) supply in order to maintain brain cell function. Our aim was to assess the influence of gestational age on the response of cerebral hemodynamics to hypoxemia and to determine thresholds of cerebral O(2) supply for preservation of

  1. Neuronal activity and ion homeostasis in the hypoxic brain

    NARCIS (Netherlands)

    Zandt, B.

    2014-01-01

    The interruption of blood flow to the brain as occurs in cardiac arrest and stroke results within minutes in irreversible damage. The development of neuroprotective treatments that prevent cell damage after stroke has so far largely been unsuccessful, while we still have an incomplete understanding

  2. Exploring the motivational brain: effects of implicit power motivation on brain activation in response to facial expressions of emotion.

    Science.gov (United States)

    Schultheiss, Oliver C; Wirth, Michelle M; Waugh, Christian E; Stanton, Steven J; Meier, Elizabeth A; Reuter-Lorenz, Patricia

    2008-12-01

    This study tested the hypothesis that implicit power motivation (nPower), in interaction with power incentives, influences activation of brain systems mediating motivation. Twelve individuals low (lowest quartile) and 12 individuals high (highest quartile) in nPower, as assessed per content coding of picture stories, were selected from a larger initial participant pool and participated in a functional magnetic resonance imaging study during which they viewed high-dominance (angry faces), low-dominance (surprised faces) and control stimuli (neutral faces, gray squares) under oddball-task conditions. Consistent with hypotheses, high-power participants showed stronger activation in response to emotional faces in brain structures involved in emotion and motivation (insula, dorsal striatum, orbitofrontal cortex) than low-power participants.

  3. Brain volumetry and self-regulation of brain activity relevant for neurofeedback.

    Science.gov (United States)

    Ninaus, M; Kober, S E; Witte, M; Koschutnig, K; Neuper, C; Wood, G

    2015-09-01

    Neurofeedback is a technique to learn to control brain signals by means of real time feedback. In the present study, the individual ability to learn two EEG neurofeedback protocols - sensorimotor rhythm and gamma rhythm - was related to structural properties of the brain. The volumes in the anterior insula bilaterally, left thalamus, right frontal operculum, right putamen, right middle frontal gyrus, and right lingual gyrus predicted the outcomes of sensorimotor rhythm training. Gray matter volumes in the supplementary motor area and left middle frontal gyrus predicted the outcomes of gamma rhythm training. These findings combined with further evidence from the literature are compatible with the existence of a more general self-control network, which through self-referential and self-control processes regulates neurofeedback learning. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Tuning and disrupting the brain – modulating the McGurk illusion with electrical stimulation

    Directory of Open Access Journals (Sweden)

    Lucas M Marques

    2014-08-01

    Full Text Available In the so-called McGurk illusion, when the synchronized presentation of the visual stimulus /ga/ is paired with the auditory stimulus /ba/, people in general hear it as /da/. Multisensory integration processing underlying this illusion seems to occur within the Superior Temporal Sulcus (STS. Herein, we present evidence demonstrating that bilateral cathodal transcranial direct current stimulation (tDCS of this area can decrease the McGurk illusion-type responses. Additionally, we show that the manipulation of this audio-visual integrated output occurs irrespective of the number of eye-fixations on the mouth of the speaker. Bilateral anodal tDCS of the Parietal Cortex also modulates the illusion, but in the opposite manner, inducing more illusion-type responses. This is the first demonstration of using non-invasive brain stimulation to modulate multisensory speech perception in an illusory context (i.e., both increasing and decreasing illusion-type responses to a verbal audio-visual integration task. These findings provide clear evidence that both the superior temporal and parietal areas contribute to multisensory integration processing related to speech perception. Specifically, STS seems fundamental for the temporal synchronization and integration of auditory and visual inputs. For its part, PPC may adjust the arrival of incoming audio and visual information to STS thereby enhancing their interaction in this latter area.

  5. Ionospheric quasi-static electric field anomalies during seismic activity in August–September 1981

    OpenAIRE

    Gousheva, M.; Danov, D.; Hristov, P.; Matova, M.

    2009-01-01

    The paper proposes new results, analyses and information for the plate tectonic situation in the processing of INTERCOSMOS-BULGARIA-1300 satellite data about anomalies of the quasi-static electric field in the upper ionosphere over activated earthquake source regions at different latitudes. The earthquake catalogue is made on the basis of information from the United State Geological Survey (USGS) website. The disturbances in ionospheric quasi-static electric fields are recorded by IESP-1 inst...

  6. Energy landscape and dynamics of brain activity during human bistable perception.

    OpenAIRE

    Watanabe, T; Masuda, N.; Megumi, F.; Kanai, R.; Rees, G.

    2014-01-01

    Individual differences in the structure of parietal and prefrontal cortex predict the stability of bistable visual perception. However, the mechanisms linking such individual differences in brain structures to behaviour remain elusive. Here we demonstrate a systematic relationship between the dynamics of brain activity, cortical structure and behaviour underpinning bistable perception. Using fMRI in humans, we find that the activity dynamics during bistable perception are well described as fl...

  7. Decoding brain activity using a large-scale probabilistic functional-anatomical atlas of human cognition.

    Directory of Open Access Journals (Sweden)

    Timothy N Rubin

    2017-10-01

    Full Text Available A central goal of cognitive neuroscience is to decode human brain activity-that is, to infer mental processes from observed patterns of whole-brain activation. Previous decoding efforts have focused on classifying brain activity into a small set of discrete cognitive states. To attain maximal utility, a decoding framework must be open-ended, systematic, and context-sensitive-that is, capable of interpreting numerous brain states, presented in arbitrary combinations, in light of prior information. Here we take steps towards this objective by introducing a probabilistic decoding framework based on a novel topic model-Generalized Correspondence Latent Dirichlet Allocation-that learns latent topics from a database of over 11,000 published fMRI studies. The model produces highly interpretable, spatially-circumscribed topics that enable flexible decoding of whole-brain images. Importantly, the Bayesian nature of the model allows one to "seed" decoder priors with arbitrary images and text-enabling researchers, for the first time, to generate quantitative, context-sensitive interpretations of whole-brain patterns of brain activity.

  8. Chronic stress and moderate physical exercise prompt widespread common activation and limited differential activation in specific brain regions.

    Science.gov (United States)

    Kim, Tae-Kyung; Han, Pyung-Lim

    2016-10-01

    Chronic stress in rodents produces depressive behaviors, whereas moderate physical exercise counteracts stress-induced depressive behaviors. Chronic stress and physical exercise appear to produce such opposing effects by changing the neural activity of specific brain regions. However, the detailed mechanisms through which the two different types of stimuli regulate brain function in opposite directions are not clearly understood. In the present study, we attempted to explore the neuroanatomical substrates mediating stress-induced behavioral changes and anti-depressant effects of exercise by examining stimulus-dependent c-Fos induction in the brains of mice that were exposed to repeated stress or exercise in a scheduled manner. Systematic and integrated analyses of c-Fos expression profiles indicated that various brain areas, including the prelimbic cortex, lateral septal area, and paraventricular nuclei of hypothalamus were commonly and strongly activated by both stress and exercise, while the lateral habenula and hippocampus were identified as being preferentially activated by stress and exercise, respectively. Exercise-dependent c-Fos expression in all regions examined in the brain occurred in both glutamatergic and GABAergic neurons. These results suggest that chronic stress and moderate exercise produce counteractive effects on mood behaviors, along with prompting widespread common activation and limited differential activation in specific brain regions. Copyright © 2016 Elsevier Ltd. All rights reserved.