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Sample records for brain electrical activity

  1. Complex networks in brain electrical activity

    CERN Document Server

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

    2005-01-01

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

  2. Relationships between parameters of gallbladder motility and brain electrical activity

    OpenAIRE

    Marfiyan, Olena M; Zukow, Walery; Popovych, Milentyna V; Ganyk, Lyubov M; Kit, Yevgen I; Ivanyts’ka, Oksana M; Kyjenko, Valeriy M

    2016-01-01

    Marfiyan Olena M, Zukow Walery, Popovych Milentyna V, Ganyk Lyubov M, Kit Yevgen I, Ivanyts’ka Oksana M, Kyjenko Valeriy M. Relationships between parameters of gallbladder motility and brain electrical activity. Journal of Education, Health and Sport. 2016;6(8):11-20. eISSN 2391-8306. DOI http://dx.doi.org/10.5281/zenodo.59271 http://ojs.ukw.edu.pl/index.php/johs/article/view/3728 https://pbn.nauka.gov.pl/sedno-webapp/works/740334     The journal has had 7 ...

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

    OpenAIRE

    O'Neil, Brian; Prichep, Leslie S.; Naunheim, Roseanne; Chabot, Robert

    2012-01-01

    Introduction: The incidence of emergency department (ED) visits for Traumatic Brain Injury (TBI) in 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 have a negative CT. This study investigates the use of quantified brain electrical activity to assess its possi...

  4. Low-level electrical currents and brain indicators of behavioral activation

    Directory of Open Access Journals (Sweden)

    F. Lolas

    1977-12-01

    Full Text Available Distinguishing between slow brain potential correlates of arousal and activation on the basis of their functional role and temporal involvement during a reaction-time task, data are presented which suggest that weak electrical polarizing currents applied to the head in human subjects modify predominantly activation indicators rather than arousal ones.

  5. Manganese-enhanced MR imaging of brain activation evoked by noxious peripheral electrical stimulation.

    Science.gov (United States)

    Cha, Myeounghoon; Lee, Kyuhong; Lee, Chulhyun; Cho, Jee-Hyun; Cheong, Chaejoon; Sohn, Jin-Hun; Lee, Bae Hwan

    2016-02-01

    As imaging technology develops, magnetic resonance imaging (MRI) has furthered our understanding of brain function by clarifying the anatomical structure and generating functional imaging data related to information processing in pain conditions. Recent studies have reported that manganese (Mn(2+))-enhanced MRI (MEMRI) provides valuable information about the functions of the central nervous system. The aim of this study was to identify specific brain regions activated during noxious electric stimulation using high-resolution MEMRI. Male Sprague Dawley rats were divided into three groups: naïve, sham electrical stimulation, and noxious electric stimulation. Under urethane with α-chloralose mixture anesthesia, a catheter was placed in the external carotid artery to administrate 20% mannitol and manganese chloride (25mM MnCl2). Noxious electric stimulation (2Hz, 10V) was applied to the hind paw with a needle electrode. Stimulation-induced neuronal activation was detected using 4.7-T MRI. In response to noxious electrical stimulation, remarkable Mn(2+)-enhanced signals were observed in the agranular insular cortex, auditory cortex, primary somatosensory cortex of the hind limb, and granular and dysgranular insular cortex, which correspond to sensory tactile electric stimulus to the hindpaws. These results indicate that the combination of MEMRI with activity-induced Mn(2+)-dependent contrast can delineate functional areas in the rat brain. PMID:26733299

  6. [The changes of basal brain electric activity in patients with epilepsy after callosotomy].

    Science.gov (United States)

    Beĭn, B N; Dravert, N E; Tatarenko, S A

    2008-01-01

    Short-term and long-term outcomes of basal brain activity were estimated in 20 epileptic patients with a medical history of callosotomy. Patients with malignant courses selected for callosotomy retained the high capacity of cerebral electric activity after surgery. In spite of limitations of bilateral synchronized irradiation of electric discharges in the brain, patients had the high power of cerebral electric genesis. A clinical study revealed the decrease of the number of seizures and their severity in patients who underwent the surgery. Thus, callosotomy plays only a palliative role in epileptic processes. Of primary importance is individual selection of anti-epileptic drugs to support cell mechanisms of epilepsy and improvement of treatment outcomes.

  7. 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.

  8. Empathy is associated with dynamic change in prefrontal brain electrical activity during positive emotion in children

    OpenAIRE

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

    2009-01-01

    Empathy is the combined ability to interpret the emotional states of others and experience resultant, related emotions. The relation between prefrontal electroencephalographic asymmetry and emotion in infants and children is well known. The relationship between positive emotion (assessed via parent-report), empathy (measured via observation) and second-by-second brain electrical activity (recorded during a pleasurable task) was investigated using a sample of 128 six to ten year olds. Contentm...

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

    OpenAIRE

    Naiphinich Kotchabhakdi; Chittin Chindaduangratn; Wichian Sittiprapaporn

    2004-01-01

    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 th...

  10. Glasgow Coma Scale, brain electric activity mapping and Glasgow Outcome Scale after hyperbaric oxygen treatment of severe brain injury

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective: To study the effect of hyperbaric oxygen (HBO) treatment of severe brain injury.Methods: Fifty-five patients were divided into a treatment group (n = 35 receiving HBO therapy ) and a control group (n = 20 receiving dehydrating, cortical steroid and antibiotic therapy) to observe the alteration of clinic GCS (Glasgow Coma Scale), brain electric activity mapping (BEAM), prognosis and GOS (Glasgow Outcome Scale) before and after hyperbaric oxygen treatment.Results: In the treatment group GCS, BEAM and GOS were improved obviously after 3 courses of treatment,GCS increased from 5.1 to 14.6 ( P < 0.01-0.001 ), the BEAM abnormal rate reduced from 94.3% to 38% (P <0.01-0.001 ), the GOS good-mild disability rate was 83.7%, and the middle-severe disability rate was 26.3%compared with the control group. There was a statistic significant difference between the two groups (P < 0.01-0.001).Conclusions: Hyperbaric oxygen treatment could improve obviously GCS, BEAM and GOS of severe brain injury patients, and effectively reduce the mortality and morbidity. It is an effective method to treat severe brain injury. two g

  11. Annotation: What Electrical Brain Activity Tells Us about Brain Function that Other Techniques Cannot Tell Us--A Child Psychiatric Perspective

    Science.gov (United States)

    Banaschewski, Tobias; Brandeis, Daniel

    2007-01-01

    Background: Monitoring brain processes in real time requires genuine subsecond resolution to follow the typical timing and frequency of neural events. Non-invasive recordings of electric (EEG/ERP) and magnetic (MEG) fields provide this time resolution. They directly measure neural activations associated with a wide variety of brain states and…

  12. Multichannel biomagnetic system for study of electrical activity in the brain and heart.

    Science.gov (United States)

    Schneider, S; Hoenig, E; Reichenberger, H; Abraham-Fuchs, K; Moshage, W; Oppelt, A; Stefan, H; Weikl, A; Wirth, A

    1990-09-01

    The authors designed a multichannel system for noninvasive measurement of the extremely weak magnetic fields generated by the brain and the heart. It uses a flat array of 37 superconducting magnetic field-sensing coils connected to sophisticated superconducting quantum interference devices. To prevent interference from external electromagnetic fields, the system is operated inside a shielded room. Complete sets of coherent data, even from spontaneous events, can be recorded. System performance was evaluated with phantom measurements and evoked-response studies. A spatial resolution of a few millimeters and a temporal resolution of a millisecond were obtained. First results in patients with partial epilepsy and investigations of the cardiac conductive pathway indicate that biomagnetism is now ready for a systematic clinical evaluation. Interpretation of measurements was facilitated by highlighting biomagnetically localized electrical activity in three-dimensional digital magnetic resonance images. PMID:2389043

  13. 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.

  14. Gender difference in electrical brain activity during presentation of various film excerpts with different emotional content.

    Science.gov (United States)

    Dimpfel, W; Wedekind, W; Keplinger, I

    2003-05-30

    Electrical activity of the human brain has been monitored using socalled charge mode (Laplacian estimates) during the exposure with short video film excerpts of 7 min duration. Eighty subjects (50% male and female) watched 5 different film excerpts (disney, animal, comedy, erotic and sex scenes) separated by 3 min pause. Comparison to a reference period of 7 min without video exposure revealed strong decreases in alpha and beta power starting from the electrode position T6 (right temporal) and spread to other brain areas with stronger attentional stimuli e.g. during the erotic and sex films. Highly statistically significant differences were observed between male and female in temporal areas, who in general developed stronger decreases than males. Females on the other hand produced significant increases in fronto-central delta and theta power which could be interpreted as expression of higher appreciation, whereas the decreases in alpha power in general are understood as signs of higher attention. The data are further proof that recording the computer aided quantitative EEG is a very fruitful and promising approach in psychophysiology. PMID:12844473

  15. Sources of Variability in Working Memory in Early Childhood: A Consideration of Age, Temperament, Language, and Brain Electrical Activity

    Science.gov (United States)

    Wolfe, Christy D.; Bell, Martha Ann

    2007-01-01

    This study investigated age-related differences in working memory and inhibitory control (WMIC) in 3 1/2-, 4-, and 4 1/2-year-olds and how these differences were associated with differences in regulatory aspects of temperament, language comprehension, and brain electrical activity. A series of cognitive control tasks was administered to measure…

  16. CLINICAL STUDY OF ISCHEMIC PENUMBRA REGION IN BRAIN ELECTRICAL ACTIVITY MAPPING

    Institute of Scientific and Technical Information of China (English)

    Liu Qingrui; Liu Mingshun; Gu Lanjie; Mei Fengjun

    2000-01-01

    Department of Neurology, Fourth Affiliated Hospital. Hebei Medical University, Shijiazhuang ABSTRACT OBJETIVE To study features and clinical usage of ischemic penumbra region(IPR) in brain electrical activity mapping(BEAM).BACKGROUND To explore the functional improvement index of IPR untraumaticly. METH0DS 69 patients with acute cerebral infarction were divided into two groups according to different therapeutic time window--early treatment group( 32 cases, treatment in 12 hours)and contral group (37 cases, treatment in 12-72 hours).They were analysed in BEAM pre-and post-treatment Results: BEAM showed that the power of infarcted core was decreased and IPR became smaller in slow waves significantly after treatment in early treatment group and this change was in good agreement with improvement of clinical functions and SPECT DISCUSSION The key to treat acute cerebral infarction was to improve functions of IPR as 8oos as possible, BEAM could show the location and size of IPR. CONCLUSION BEAM was one of important index in evaluating the function of IPR.

  17. Evaluation of the brain activation induced by functional electrical stimulation and voluntary contraction using functional magnetic resonance imaging

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    Joa Kyung-Lim

    2012-07-01

    Full Text Available Abstract Background To observe brain activation induced by functional electrical stimulation, voluntary contraction, and the combination of both using functional magnetic resonance imaging (fMRI. Methods Nineteen healthy young men were enrolled in the study. We employed a typical block design that consisted of three sessions: voluntary contraction only, functional electrical stimulation (FES-induced wrist extension, and finally simultaneous voluntary and FES-induced movement. MRI acquisition was performed on a 3.0 T MR system. To investigate activation in each session, one-sample t-tests were performed after correcting for false discovery rate (FDR; p t-test was performed using a contrast map (p  Results In the voluntary contraction alone condition, brain activation was observed in the contralateral primary motor cortex (MI, thalamus, bilateral supplementary motor area (SMA, primary sensory cortex (SI, secondary somatosensory motor cortex (SII, caudate, and cerebellum (mainly ipsilateral. During FES-induced wrist movement, brain activation was observed in the contralateral MI, SI, SMA, thalamus, ipsilateral SII, and cerebellum. During FES-induced movement combined with voluntary contraction, brain activation was found in the contralateral MI, anterior cingulate cortex (ACC, SMA, ipsilateral cerebellum, bilateral SII, and SI. The activated brain regions (number of voxels of the MI, SI, cerebellum, and SMA were largest during voluntary contraction alone and smallest during FES alone. SII-activated brain regions were largest during voluntary contraction combined with FES and smallest during FES contraction alone. The brain activation extent (maximum t score of the MI, SI, and SII was largest during voluntary contraction alone and smallest during FES alone. The brain activation extent of the cerebellum and SMA during voluntary contraction alone was similar during FES combined with voluntary contraction; however, cerebellum and SMA activation

  18. Activity-dependent plasticity of electrical synapses: increasing evidence for its presence and functional roles in the mammalian brain.

    Science.gov (United States)

    Haas, Julie S; Greenwald, Corey M; Pereda, Alberto E

    2016-01-01

    Gap junctions mediate electrical synaptic transmission between neurons. While the actions of neurotransmitter modulators on the conductance of gap junctions have been extensively documented, increasing evidence indicates they can also be influenced by the ongoing activity of neural networks, in most cases via local interactions with nearby glutamatergic synapses. We review here early evidence for the existence of activity-dependent regulatory mechanisms as well recent examples reported in mammalian brain. The ubiquitous distribution of both neuronal connexins and the molecules involved suggest this phenomenon is widespread and represents a property of electrical transmission in general. PMID:27230776

  19. 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

  20. 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. PMID:6165544

  1. Thirty minute transcutaneous electric acupoint stimulation modulates resting state brain activities: a perfusion and BOLD fMRI study.

    Science.gov (United States)

    Jiang, Yin; Hao, Ying; Zhang, Yue; Liu, Jing; Wang, Xiaoying; Han, Jisheng; Fang, Jing; Zhang, Jue; Cui, Cailian

    2012-05-31

    Increasing neuroimaging studies have focused on the sustained after effects of acupuncture, especially for the changes of brain activities in rest. However, short-period stimuli have mostly been chosen in these works. The present study aimed to investigate how the resting state brain activities in healthy subjects were modulated by relatively long-period (30 min) acupuncture, a widely used modality in clinical practice. Transcutaneous electric acupoint stimulation (TEAS) or intermittent minimal TEAS (MTEAS) were given for 30 min to 40 subjects. Functional MRI (fMRI) data were collected including the pre-stimulation resting state and the post-stimulation resting state, using dual-echo arterial spin labeling (ASL) techniques, representing both cerebral blood flow (CBF) signals and blood oxygen-dependent level (BOLD) signals simultaneously. Following 30 min TEAS, but not MTEAS, the mean global CBF decreased, and a significant decrease of regional CBF was observed in SI, insula, STG, MOG and IFG. Functional connectivity analysis showed more secure and spatially extended connectivity of both the DMN and SMN after 30 min TEAS. Our results implied that modulation of the regional brain activities and network connectivity induced by thirty minute TEAS may associate with the acupuncture-related therapeutic effects. Furthermore, the resting state regional CBF quantified by ASL perfusion fMRI may serve as a potential biomarker in future acupuncture studies. PMID:22541167

  2. 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

  3. 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 typ...

  4. Noise power associated with decreased task-induced variability of brain electrical activity in schizophrenia.

    Science.gov (United States)

    Molina, Vicente; Bachiller, Alejandro; Suazo, Vanessa; Lubeiro, Alba; Poza, Jesús; Hornero, Roberto

    2016-02-01

    In schizophrenia, both increased baseline metabolic and electroencephalographic (EEG) activities as well as decreased task-related modulation of neural dynamics have been reported. Noise power (NP) can measure the background EEG activity during task performance, and Shannon entropy (SE) is useful for quantifying the global modulation of EEG activity with a high temporal resolution. In this study, we have assessed the possible relationship between increased NP in theta and gamma bands and decreased SE modulation in 24 patients with schizophrenia and 26 controls over the parietal and central regions during a P300 task. SE modulation was calculated as the change from baseline to the active epoch (i.e., 150-550 ms following the target stimulus onset). Patients with schizophrenia displayed statistically significant higher NP values and lower SE modulation than healthy controls. We found a significant association between gamma NP and SE in all of the participants. Specifically, a NP increase in the gamma band was followed by a decrease in SE change. These results support the notion that an excess of gamma activity, unlocked to the task being performed, is accompanied by a decreased modulation of EEG activity in schizophrenia.

  5. Interactions between noradrenaline and corticosteroids in the brain: from electrical activity to cognitive performance.

    NARCIS (Netherlands)

    H.J. Krugers; H. Karst; M. Joëls

    2012-01-01

    One of the core reactions in response to a stressful situation is the activation of the hypothalamus-pituitary-adrenal axis which increases the release of glucocorticoid hormones from the adrenal glands. In concert with other neuro-modulators, such as (nor)adrenaline, these hormones enable and promo

  6. Interactions between noradrenaline and corticosteroids in the brain: from electrical activity to cognitive performance

    OpenAIRE

    Krugers, Harmen J.; Henk eKarst; Marian eJoels

    2012-01-01

    One of the core reactions in response to a stressful situation is the activation of the hypothalamus–pituitary–adrenal (HPA) axis which increases the release of glucocorticoid hormones from the adrenal glands. In concert with other neuro-modulators, such as (nor)adrenaline, these hormones enable and promote cognitive adaptation to stressful events. Recent studies have demonstrated that glucocorticoid hormones and noradrenaline, via their receptors, can both rapidly and persistently regulate t...

  7. Interactions between noradrenaline and corticosteroids in the brain: from electrical activity to cognitive performance

    Directory of Open Access Journals (Sweden)

    Harmen J Krugers

    2012-04-01

    Full Text Available One of the core reactions in response to a stressful situation is the activation of the hypothalamus–pituitary–adrenal (HPA axis which increases the release of glucocorticoid hormones from the adrenal glands. In concert with other neuro-modulators, such as (noradrenaline, these hormones enable and promote cognitive adaptation to stressful events. Recent studies have demonstrated that glucocorticoid hormones and noradrenaline, via their receptors, can both rapidly and persistently regulate the function of excitatory synapses which are critical for storage of information. Here we will review how glucocorticoids and noradrenaline alone and in synergy dynamically tune these synapses in the hippocampus and amygdala, and discuss how these hormones interact to promote behavioral adaptation to stressful situations.

  8. Drug polyconsumption is associated with increased synchronization of brain electrical-activity at rest and in a counting task.

    Science.gov (United States)

    Coullaut-Valera, R; Arbaiza, I; Bajo, R; Arrúe, R; López, M E; Coullaut-Valera, J; Correas, A; López-Sanz, D; Maestu, F; Papo, D

    2014-02-01

    Drug abusers typically consume not just one but several types of drugs, starting from alcohol and marijuana consumption, and then dramatically lapsing into addiction to harder drugs, such as cocaine, heroin, or amphetamine. The brain of drug abusers presents various structural and neurophysiological abnormalities, some of which may predate drug consumption onset. However, how these changes translate into modifications in functional brain connectivity is still poorly understood. To characterize functional connectivity patterns, we recorded Electroencephalogram (EEG) activity from 21 detoxified drug abusers and 20 age-matched control subjects performing a simple counting task and at rest activity. To evaluate the cortical brain connectivity network we applied the Synchronization Likelihood algorithm. The results showed that drug abusers had higher synchronization levels at low frequencies, mainly in the θ band (4-8 Hz) between frontal and posterior cortical regions. During the counting task, patients showed increased synchronization in the β (14-35 Hz), and γ (35-45 Hz) frequency bands, in fronto-posterior and interhemispheric temporal regions. Taken together 'slow-down' at rest and task-related 'over-exertion' could indicate that the brain of drug abusers is suffering from a premature form of ageing. Future studies will clarify whether this condition can be reversed following prolonged periods of abstinence.

  9. Deep Brain Electrical Stimulation in Epilepsy

    Science.gov (United States)

    Rocha, Luisa L.

    2008-11-01

    The deep brain electrical stimulation has been used for the treatment of neurological disorders such as Parkinson's disease, chronic pain, depression and epilepsy. Studies carried out in human brain indicate that the application of high frequency electrical stimulation (HFS) at 130 Hz in limbic structures of patients with intractable temporal lobe epilepsy abolished clinical seizures and significantly decreased the number of interictal spikes at focus. The anticonvulsant effects of HFS seem to be more effective in patients with less severe epilepsy, an effect associated with a high GABA tissue content and a low rate of cell loss. In addition, experiments using models of epilepsy indicate that HFS (pulses of 60 μs width at 130 Hz at subthreshold current intensity) of specific brain areas avoids the acquisition of generalized seizures and enhances the postictal seizure suppression. HFS is also able to modify the status epilepticus. It is concluded that the effects of HFS may be a good strategy to reduce or avoid the epileptic activity.

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

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    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

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

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    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.

  12. 海洛因依赖者的脑电地形图%MAPS OF BRAIN ELECTRICAL ACTIVITY OF HEROIN ADDICTS

    Institute of Scientific and Technical Information of China (English)

    杨宝元; 张国印; 徐本树; 铁恩贵

    2001-01-01

    目的:了解海洛因依赖者存在戒断症状时的脑电地形图的特征。方法:用脑电图机记录32例有戒断症状的海洛因依赖者及34例正常人的脑电地形图并用计算机进行定量分析。结果:与对照组比较,海洛因依赖者(1)慢波频段(δ、θ)功率值增高;(2)α1、α2功率值减低;(3)快波频段(β1、β2)的枕区(O1、O2)功率值增高。结论:从脑电生理角度观察海洛因对大脑功能的损害是有意义的。%Objective: To study the character of the brain electricalactivity maps(BEAM) of heroin addicts with withdrawal syndromes. Method: The brain electrical activity maps ( BEAM ) of 32 heroin addicts with withdrawal syndromes and 34 normal controls were recorded with electroencephalograph and quantitatively analysed with computer. Result: In the BEAM of heroin addicts with withdrawal syndromes, the power values of slow wave(δ,θ) increased; α1 , α2 decreased; rapid wave frequency sect (β1, β2) in occipital area (O1,O2)increased. Conclusion: Observation of brain electrical physiology has some value in the assessment of the damage of cerebral function caused by heroin.

  13. 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

  14. A method for recording resistance changes non-invasively during neuronal depolarization with a view to imaging brain activity with electrical impedance tomography.

    Science.gov (United States)

    Gilad, Ori; Ghosh, Anthony; Oh, Dongin; Holder, David S

    2009-05-30

    Electrical impedance tomography (EIT) is a recently developed medical imaging method which has the potential to produce images of fast neuronal depolarization in the brain. The principle is that current remains in the extracellular space at rest but passes into the intracellular space during depolarization through open ion channels. As current passes into the intracellular space across the capacitance of cell membranes at higher frequencies, applied current needs to be below 100 Hz. A method is presented for its measurement with subtraction of the contemporaneous evoked potentials which occur in the same frequency band. Neuronal activity is evoked by stimulation and resistance is recorded from the potentials resulting from injection of a constant current square wave at 1 Hz with amplitude less than 25% of the threshold for stimulating neuronal activity. Potentials due to the evoked activity and the injected square wave are removed by subtraction. The method was validated with compound action potentials in crab walking leg nerve. Resistance changes of -0.85+/-0.4% (mean+/-SD) occurred which decreased from -0.97+/-0.43% to -0.46+/-0.16% with spacing of impedance current application electrodes from 2 to 8 mm but did not vary significantly with applied currents of 1-10 microA. These tallied with biophysical modelling, and so were consistent with a genuine physiological origin. This method appears to provide a reproducible and artefact free means for recording resistance changes during neuronal activity which could lead to the long-term goal of imaging of fast neural activity in the brain.

  15. Parental rearing behavior prospectively predicts adolescents’ risky decision-making and feedback-related electrical brain activity

    NARCIS (Netherlands)

    Euser, A.S.; Evans, B.E.; Greaves-Lord, K.; Huizink, A.C.; Franken, I.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

  16. Investigation of potential artefactual changes in measurements of impedance changes during evoked activity: implications to electrical impedance tomography of brain function.

    Science.gov (United States)

    Aristovich, Kirill Y; Dos Santos, Gustavo S; Holder, David S

    2015-06-01

    Electrical impedance tomography (EIT) could provide images of fast neural activity in the adult human brain with a resolution of 1 ms and 1 mm by imaging impedance changes which occur as ion channels open during neuronal depolarization. The largest changes occur at dc and decrease rapidly over 100 Hz. Evoked potentials occur in this bandwidth and may cause artefactual apparent impedance changes if altered by the impedance measuring current. These were characterized during the compound action potential in the walking leg nerves of Cancer pagurus, placed on Ag/AgCl hook electrodes, to identify how to avoid artefactual changes during brain EIT. Artefact-free impedance changes (δZ) decreased with frequency from -0.045 ± 0.01% at 225 Hz to -0.02 ± 0.01% at 1025 Hz (mean ± 1 SD, n = 24 in 12 nerves) which matched changes predicted by a finite element model. Artefactual δZ reached c.300% and 50% of the genuine membrane impedance change at 225 Hz and 600 Hz respectively but decreased with frequency of the applied current and was negligible above 1 kHz. The proportional amplitude (δZ (%)) of the artefact did not vary significantly with the amplitude of injected current of 5-20 µA pp. but decreased significantly from -0.09 ± 0.024 to -0.03 ± 0.023% with phase of 0 to 45°. For fast neural EIT of evoked activity in the brain, artefacts may arise with applied current of >10 µA. Independence of δZ with respect to phase but not the amplitude of applied current controls for them; they can be minimized by randomizing the phase of the applied measuring current and excluded by recording at >1 kHz. PMID:26009486

  17. Interaction between electrical modulation of the brain and pharmacotherapy to control pharmacoresistant epilepsy.

    Science.gov (United States)

    Rocha, Luisa

    2013-05-01

    In spite of the high success rate of many surgical procedures for pharmacoresistant epilepsy, a substantial number of patients do not become seizure-free. Different strategies for electrical modulation of the brain such as Deep Brain Stimulation, Vagal Nerve Stimulation and Transcraneal Magnetic Stimulation have gained considerable interest in the last decade as alternative therapies for patients with medically refractory epilepsy. Research into the mechanism of action of the strategies for electrical modulation of the brain suggests a crucial role of different molecules and channels such as glutamate, γ-aminobutyric acid, adenosine, brain-derived neurotrophic factor, calcium channels, sodium channels as well as extracellular potassium. Electrical modulation of the brain may reduce the overexpression of P-glycoprotein, a drug efflux transporter that reduces the absorption of antiepileptic drugs. Electrical modulation of the brain induces long-term effects associated with beneficial consequences on clinical symptoms observed during the postictal state. In addition, electrical modulation of the brain might also promote the neurogenesis in subjects with pharmacoresistant epilepsy in whom this process is decreased. Targeting the regulatory pathways in charge of the effects of electrical modulation of the brain is discussed as a means to improve its efficacy. Electrical modulation of the brain combined with pharmacotherapy may represent an innovative approach to avoid epileptogenesis, reduce seizure activity, induce beneficial effects during the postictal state, diminish the amount of antiepileptic drugs, and improve alertness, memory and mood in pharmacoresistant epilepsy.

  18. Fueling and imaging brain activation

    Directory of Open Access Journals (Sweden)

    Gerald A Dienel

    2012-07-01

    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.

  19. Electrical Tongue Stimulation Normalizes Activity Within the Motion-Sensitive Brain Network in Balance-Impaired Subjects as Revealed by Group Independent Component Analysis

    OpenAIRE

    Wildenberg, Joseph C.; Tyler, Mitchell E.; Danilov, Yuri P; Kaczmarek, Kurt A.; Meyerand, Mary E.

    2011-01-01

    Multivariate analysis of functional magnetic resonance imaging (fMRI) data allows investigations into network behavior beyond simple activations of individual regions. We apply group independent component analysis to fMRI data collected in a previous study looking at the sustained neuromodulatory effects of electrical tongue stimulation in balance-impaired individuals. Twelve subjects with balance disorders viewed optic flow in an fMRI scanner before and after 5 days of electrical tongue stim...

  20. 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.

  1. Submillisecond unmasked subliminal visual stimuli evoke electrical brain responses.

    Science.gov (United States)

    Sperdin, Holger F; Spierer, Lucas; Becker, Robert; Michel, Christoph M; Landis, Theodor

    2015-04-01

    Subliminal perception is strongly associated to the processing of meaningful or emotional information and has mostly been studied using visual masking. In this study, we used high density 256-channel EEG coupled with an liquid crystal display (LCD) tachistoscope to characterize the spatio-temporal dynamics of the brain response to visual checkerboard stimuli (Experiment 1) or blank stimuli (Experiment 2) presented without a mask for 1 ms (visible), 500 µs (partially visible), and 250 µs (subliminal) by applying time-wise, assumption-free nonparametric randomization statistics on the strength and on the topography of high-density scalp-recorded electric field. Stimulus visibility was assessed in a third separate behavioral experiment. Results revealed that unmasked checkerboards presented subliminally for 250 µs evoked weak but detectable visual evoked potential (VEP) responses. When the checkerboards were replaced by blank stimuli, there was no evidence for the presence of an evoked response anymore. Furthermore, the checkerboard VEPs were modulated topographically between 243 and 296 ms post-stimulus onset as a function of stimulus duration, indicative of the engagement of distinct configuration of active brain networks. A distributed electrical source analysis localized this modulation within the right superior parietal lobule near the precuneus. These results show the presence of a brain response to submillisecond unmasked subliminal visual stimuli independently of their emotional saliency or meaningfulness and opens an avenue for new investigations of subliminal stimulation without using visual masking. PMID:25487054

  2. Comparison of detection results of hypoxic-ischemic encephalopathy at different degrees in infant patients between brain electrical activity mapping, transcranial Doppler sonography and computer tomography examinations

    Institute of Scientific and Technical Information of China (English)

    Dongruo He; Xiaoying Xu; Yinghui Zhang; Guochao Han

    2006-01-01

    BACKGROUND; It has been proved that brain electrical activity mapping (BEAM) and transcranial Doppler (TCD) detection can reflect the function of brain cell and its diseased degree of infant patients with moderate to severe hypoxic-ischemic encephalopathy (HIE).OBJECTIVE: To observe the abnormal results of HIE at different degrees detected with BEAM and TCD in infant patients, and compare the detection results at the same time point between BEAM, TCD and computer tomography (CT) examinations.DESTGN: Contrast observation.SETTING: Departments of Neuro-electrophysiology and Pediatrics, Second Affiliated Hospital of Qiqihar Medical College.PARTICTPANTS: Totally 416 infant patients with HIE who received treatment in the Department of Newborn Infants, Second Affiliated Hospital of Qiqihar Medical College during January 2001 and December 2005. The infant patients, 278 male and 138 female, were at embryonic 37 to 42 weeks and weighing 2.0 to 4.1 kg, and they were diagnosed with CT and met the diagnostic criteria of HIE of newborn infants compiled by Department of Neonatology, Pediatric Academy, Chinese Medical Association. According to diagnostic criteria, 130patients were mild abnormal, 196 moderate abnormal and 90 severe abnormal. The relatives of all the infant patients were informed of the experiment.METHODS: BEAM and TCD examinations were performed in the involved 416 infant patients with HIE at different degrees with DYD2000 16-channel BEAM instrument and EME-2000 ultrasonograph before preliminary diagnosis treatment (within 1 month after birth) and 1,3,6,12 and 24 months after birth, and detected results were compared between BEAM, TCD and CT examinations.MATN OUTCOME MEASURES: Comparison of detection results of HIE at different time points in infant patients between BEAM, TCD and CT examinations. RESULTS: All the 416 infant patients with HIE participated in the result analysis. ① Comparison of the detected results in infant patients with mild HIE at different

  3. Look at Epilepsy: Electrical Outbursts in the Brain

    Science.gov (United States)

    ... our exit disclaimer . Subscribe A Look at Epilepsy Electrical Outbursts in the Brain When you hear the ... epilepsy. Prevent head injuries by wearing seatbelts and bicycle helmets, and make sure kids are properly secured ...

  4. 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.

  5. Resting state brain activity and functional brain mapping

    Institute of Scientific and Technical Information of China (English)

    Zhao Xiaohu; Wang Peijun; Tang Xiaowei

    2007-01-01

    Functional brain imaging studies commonly use either resting or passive task states as their control conditions, and typically identify the activation brain region associated with a specific task by subtracting the resting from the active task conditions. Numerous studies now suggest, however, that the resting state may not reflect true mental "rest" conditions. The mental activity that occurs during"rest" might therefore greatly influence the functional neuroimaging observations that are collected through the usual subtracting analysis strategies. Exploring the ongoing mental processes that occur during resting conditions is thus of particular importance for deciphering functional brain mapping results and obtaining a more comprehensive understanding of human brain functions. In this review article, we will mainly focus on the discussion of the current research background of functional brain mapping at resting state and the physiological significance of the available neuroimaging data.

  6. Economic substitutability of electrical brain stimulation, food, and water.

    OpenAIRE

    Green, L; Rachlin, H

    1991-01-01

    Concurrent variable-ratio schedules of electrical brain stimulation, food, and water were paired in various combinations as reinforcement of rats' lever presses. Relative prices of the concurrent reinforcers were varied by changing the ratio of the response requirements on the two levers. Economic substitutability, measured by the sensitivity of response ratio to changes in relative price, was highest with brain stimulation reinforcement of presses on both levers and lowest with food reinforc...

  7. A novel method for recording neuronal depolarization with recording at 125-825 Hz: implications for imaging fast neural activity in the brain with electrical impedance tomography.

    Science.gov (United States)

    Oh, T; Gilad, O; Ghosh, A; Schuettler, M; Holder, D S

    2011-05-01

    Electrical impedance tomography (EIT) is a recently developed medical imaging method which has the potential to produce images of fast neuronal depolarization in the brain. Previous modelling suggested that applied current needed to be below 100 Hz but the signal-to-noise ratio (SNR) recorded with scalp electrodes during evoked responses was too low to permit imaging. A novel method in which contemporaneous evoked potentials are subtracted is presented with current applied at 225 Hz to cerebral cortex during evoked activity; although the signal is smaller than at DC by about 10×, the principal noise from the EEG is reduced by about 1000×, resulting in an improved SNR. It was validated with recording of compound action potentials in crab walking leg nerve where peak changes of -0.2% at 125 and 175 Hz tallied with biophysical modelling. In recording from rat cerebral cortex during somatosensory evoked responses, peak impedance decreases of -0.07 ± 0.006% (mean ± SE) with a SNR of >50 could be recorded at 225 Hz. This method provides a reproducible and artefact free means for recording resistance changes during neuronal activity which could form the basis for imaging fast neural activity in the brain.

  8. Measuring the local electrical conductivity of human brain tissue

    Science.gov (United States)

    Akhtari, M.; Emin, D.; Ellingson, B. M.; Woodworth, D.; Frew, A.; Mathern, G. W.

    2016-02-01

    The electrical conductivities of freshly excised brain tissues from 24 patients were measured. The diffusion-MRI of the hydrogen nuclei of water molecules from regions that were subsequently excised was also measured. Analysis of these measurements indicates that differences between samples' conductivities are primarily due to differences of their densities of solvated sodium cations. Concomitantly, the sample-to-sample variations of their diffusion constants are relatively small. This finding suggests that non-invasive in-vivo measurements of brain tissues' local sodium-cation density can be utilized to estimate its local electrical conductivity.

  9. 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.

  10. Percussion and electrical stunning of Atlantic salmon (Salmo salar) after dewatering and subsequent effect on brain and heart activities nd subsequent

    NARCIS (Netherlands)

    Lambooij, E.; Grimsboe, E.; Vis, van de J.W.; Reimert, H.G.M.; Nortvedt, R.; Roth, B.

    2010-01-01

    The overall objective of the study was to evaluate a percussive and an electrical stunning method under laboratory conditions in Atlantic salmon. Evidence of unconsciousness and insensibility of the salmon was provided on the electroencephalogram (EEG) by the appearance of slow waves and spikes, fol

  11. Computerised brain electrical activity findings of parkinson patients suffering from hyperkinetic side effects (hypersensitive dopamine syndrome) and a review of possible sources.

    Science.gov (United States)

    Fünfgeld, E W

    1995-01-01

    Among 2,000 Park. pat. hospitalised during the years 1988 till 1990 we found 61 pat. with hyperkinetic side-effects in the sequence of a long-term L-dopa treatment. 43 (mean age 64y.) had a complete clinical data set and hyperkinesia ratings (AIMS scale). Compared to the system's data base--none of these patients showed a strickly normal CEEG. Our standard parkinson treatment was established in 1986: L-dopa as low as possible, dopamine agonists low, amantadines as high as necessary, L-deprenyl till 10 mg and anticholinergics--no, if possible. Our pat. group got initially a mean of 508 mg L-dopa, at the end of the study 296 mg. Conventional EEG (Picker-Schwarzer) and CEEG data were recorded (Dynamic Brain Mapping, Itil). Clinical and CEEG follow-up investigations were done after 2 weeks and 2 years. At follow-up, a reduction of the hyperkinesias was found in 43 patients (AIMS scale). 28 pat. received an additional treatment with nootropic drugs, 15 pat. were without this additional therapy. The visually evaluated CEEG at the latter group showed an acceleration ("response") in 33%, but among the patients with nootropic drugs the acceleration was seen in 66%. In patients without nootropics the mean delta power increased, patients additionally treated showed a reduction of delta. In cases of high L-dopa dosage--associated with severe hyperkinetic side effects--more slow waves were registered. The non-nootropic treated patients were divided into two groups--non-responders and the responders: a) Non-responders (n = 10) showed a significant reduction of alpha and a significant increase of delta and theta, b) Responders (5 pat.) without nootropics had a significant reduction of theta and a increase of alpha, but the acceleration is less pronounced than in the responder group with nootropics. Without co-medication a high L-dopa dosage may provoke/facilitate an organic cerebral dysfunction. The nootropic-treated but non-responder group showed no significant changes (n = 13

  12. 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...... high-quality head models from magnetic resonance images and their usage in subsequent field calculations based on the FEM. The pipeline starts by extracting the borders between skin, skull, cerebrospinal fluid, gray and white matter. The quality of the resulting surfaces is subsequently improved...... the successful usage of the pipeline in six subjects, including field calculations for transcranial magnetic stimulation and transcranial direct current stimulation. The quality of the head volume meshes is validated both in terms of capturing the underlying anatomy and of the well-shapedness of the mesh...

  13. Brain electric fields, belief in the paranormal, and reading of emotion words

    OpenAIRE

    Gianotti, Lorena R R

    2008-01-01

    The present work reports two experiments on brain electric correlates of cognitive and emotional functions. (1) Studying paranormal belief, 35-channel resting EEG (10 believers and 13 skeptics) was analyzed with "Low Resolution Electromagnetic Tomography" (LORETA) in seven frequency bands. LORETA gravity centers of all bands shifted to the left in believers vs. sceptics, and showed that believers had stronger left fronto-temporo-parietal activity than skeptics. Self-rating of affective attitu...

  14. Anger Style, Psychopathology, and Regional Brain Activity

    OpenAIRE

    Stewart, Jennifer L.; Levin, Rebecca L.; Sass, Sarah M.; Heller, Wendy; Gregory A. Miller

    2008-01-01

    Depression and anxiety often involve high levels of trait anger and disturbances in anger expression. Reported anger experience and outward anger expression have recently been associated with left-biased asymmetry of frontal cortical activity, assumed to reflect approach motivation. However, different styles of anger expression could presumably involve different brain mechanisms and/or interact with psychopathology to produce various patterns of brain asymmetry. The present study explored the...

  15. [Synchronized, oscillatory brain activity in visual perception].

    Science.gov (United States)

    Braunitzer, Gábor

    2008-09-30

    The present study investigates one of the most promising developments of the brain-mind question, namely the possible links between synchronized oscillatory brain activity and certain (visual) perceptual processes. Through a review of the relevant literature, the author introduces the reader to the most important theories of coherent perception ('binding'), and makes an attempt to show how synchronization of EEG-registrable oscillatory activities from various frequency bands might explain binding. Finally, a number of clinical problems are also mentioned, regarding which the presented theoretical framework might deserve further consideration. PMID:18841649

  16. Telomerase activity in 144 brain tumours.

    OpenAIRE

    Sano, T; Asai, A.; Mishima, K.; Fujimaki, T.; Kirino, T.

    1998-01-01

    Unlimited proliferation in immortalized cells is believed to be highly dependent on the activity of telomerase, a ribonucleoprotein that synthesizes telomeric repeats onto chromosome ends. Using a polymerase chain reaction-based telomeric repeat amplification protocol (TRAP) assay, we analysed telomerase activity in 99 benign and 45 malignant brain tumours. The TRAP assay results were quantitated by normalizing the telomerase activity of each specimen to that of human glioma cell line T98G to...

  17. Repetitive Transcranial Magnetic Stimulation Activates Specific Regions in Rat Brain

    Science.gov (United States)

    Ji, Ru-Rong; Schlaepfer, Thomas E.; Aizenman, Carlos D.; Epstein, Charles M.; Qiu, Dike; Huang, Justin C.; Rupp, Fabio

    1998-12-01

    Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive technique to induce electric currents in the brain. Although rTMS is being evaluated as a possible alternative to electroconvulsive therapy for the treatment of refractory depression, little is known about the pattern of activation induced in the brain by rTMS. We have compared immediate early gene expression in rat brain after rTMS and electroconvulsive stimulation, a well-established animal model for electroconvulsive therapy. Our result shows that rTMS applied in conditions effective in animal models of depression induces different patterns of immediate-early gene expression than does electroconvulsive stimulation. In particular, rTMS evokes strong neural responses in the paraventricular nucleus of the thalamus (PVT) and in other regions involved in the regulation of circadian rhythms. The response in PVT is independent of the orientation of the stimulation probe relative to the head. Part of this response is likely because of direct activation, as repetitive magnetic stimulation also activates PVT neurons in brain slices.

  18. Science Activities in Energy: Electrical Energy.

    Science.gov (United States)

    Oak Ridge Associated Universities, TN.

    Presented is a science activities in energy package which includes 16 activities relating to electrical energy. Activities are simple, concrete experiments for fourth, fifth and sixth grades which illustrate principles and problems relating to energy. Each activity is outlined in a single card which is introduced by a question. A teacher's…

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

    Science.gov (United States)

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

    2016-03-01

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

  20. CT findings of the brain damages resulting from the high voltage electric injuries

    Energy Technology Data Exchange (ETDEWEB)

    Kim, So Eun; Kim, Young Keun; Shim, Hyang Yi; Lee, Shin Hyung; Lee, Chang Joon [National Medical Center, Seoul (Korea, Republic of)

    1994-02-15

    The purpose of this study is to evaluate the CT features and pathogenesis of the electric brain injuries. We reviewed the CT scans of 3 patients injured by high-voltage electricity. We evaluated the findings early and delayed periods in each patients. The early CT findings were diffuse brain edema, scalp swelling, and focal hemorrhagic contusion. The findings of delayed period were cerebral infarction, pneumocephalus, brain abscess, and pneumatocele. CT was useful to correlate the pathogenesis and variable features of electric brain injuries.

  1. PPG neurons of the lower brain stem and their role in brain GLP-1 receptor activation.

    Science.gov (United States)

    Trapp, Stefan; Cork, Simon C

    2015-10-15

    Within the brain, glucagon-like peptide-1 (GLP-1) affects central autonomic neurons, including those controlling the cardiovascular system, thermogenesis, and energy balance. Additionally, GLP-1 influences the mesolimbic reward system to modulate the rewarding properties of palatable food. GLP-1 is produced in the gut and by hindbrain preproglucagon (PPG) neurons, located mainly in the nucleus tractus solitarii (NTS) and medullary intermediate reticular nucleus. Transgenic mice expressing glucagon promoter-driven yellow fluorescent protein revealed that PPG neurons not only project to central autonomic control regions and mesolimbic reward centers, but also strongly innervate spinal autonomic neurons. Therefore, these brain stem PPG neurons could directly modulate sympathetic outflow through their spinal inputs to sympathetic preganglionic neurons. Electrical recordings from PPG neurons in vitro have revealed that they receive synaptic inputs from vagal afferents entering via the solitary tract. Vagal afferents convey satiation to the brain from signals like postprandial gastric distention or activation of peripheral GLP-1 receptors. CCK and leptin, short- and long-term satiety peptides, respectively, increased the electrical activity of PPG neurons, while ghrelin, an orexigenic peptide, had no effect. These findings indicate that satiation is a main driver of PPG neuronal activation. They also show that PPG neurons are in a prime position to respond to both immediate and long-term indicators of energy and feeding status, enabling regulation of both energy balance and general autonomic homeostasis. This review discusses the question of whether PPG neurons, rather than gut-derived GLP-1, are providing the physiological substrate for the effects elicited by central nervous system GLP-1 receptor activation.

  2. Brain Activation During Singing: "Clef de Sol Activation" Is the "Concert" of the Human Brain.

    Science.gov (United States)

    Mavridis, Ioannis N; Pyrgelis, Efstratios-Stylianos

    2016-03-01

    Humans are the most complex singers in nature, and the human voice is thought by many to be the most beautiful musical instrument. Aside from spoken language, singing represents a second mode of acoustic communication in humans. The purpose of this review article is to explore the functional anatomy of the "singing" brain. Methodologically, the existing literature regarding activation of the human brain during singing was carefully reviewed, with emphasis on the anatomic localization of such activation. Relevant human studies are mainly neuroimaging studies, namely functional magnetic resonance imaging and positron emission tomography studies. Singing necessitates activation of several cortical, subcortical, cerebellar, and brainstem areas, served and coordinated by multiple neural networks. Functionally vital cortical areas of the frontal, parietal, and temporal lobes bilaterally participate in the brain's activation process during singing, confirming the latter's role in human communication. Perisylvian cortical activity of the right hemisphere seems to be the most crucial component of this activation. This also explains why aphasic patients due to left hemispheric lesions are able to sing but not speak the same words. The term clef de sol activation is proposed for this crucial perisylvian cortical activation due to the clef de sol shape of the topographical distribution of these cortical areas around the sylvian fissure. Further research is needed to explore the connectivity and sequence of how the human brain activates to sing. PMID:26966964

  3. Physical activity and brain plasticity in late adulthood

    OpenAIRE

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

    2013-01-01

    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,...

  4. Scale-free brain activity: past, present, and future.

    Science.gov (United States)

    He, Biyu J

    2014-09-01

    Brain activity observed at many spatiotemporal scales exhibits a 1/f-like power spectrum, including neuronal membrane potentials, neural field potentials, noninvasive electroencephalography (EEG), magnetoencephalography (MEG), and functional magnetic resonance imaging (fMRI) signals. A 1/f-like power spectrum is indicative of arrhythmic brain activity that does not contain a predominant temporal scale (hence, 'scale-free'). This characteristic of scale-free brain activity distinguishes it from brain oscillations. Although scale-free brain activity and brain oscillations coexist, our understanding of the former remains limited. Recent research has shed light on the spatiotemporal organization, functional significance, and potential generative mechanisms of scale-free brain activity, as well as its developmental and clinical relevance. A deeper understanding of this prevalent brain signal should provide new insights into, and analytical tools for, cognitive neuroscience.

  5. Interactions between cardiac, respiratory, and brain activity in humans

    Science.gov (United States)

    Musizza, Bojan; Stefanovska, Aneta

    2005-05-01

    The electrical activity of the heart (ECG), respiratory function and electric activity of the brain (EEG) were simultaneously recorded in conscious, healthy humans. Instantaneous frequencies of the heart beat, respiration and α-waves were then determined from 30-minutes recordings. The instantaneous cardiac frequency was defined as the inverse value of the time interval between two consecutive R-peaks. The instantaneous respiratory frequency was obtained from recordings of the excursions of thorax by application of the Hilbert transform. To obtain the instantaneous frequency of α-waves, the EEG signal recorded from the forehead was first analysed using the wavelet transform. Then the frequency band corresponding to α-waves was extracted and the Hilbert transform applied. Synchronization analysis was performed and the direction of coupling was ascertained, using pairs of instantaneous frequencies in each case. It is shown that the systems are weakly bidirectionally coupled. It was confirmed that, in conscious healthy humans, respiration drives cardiac activity. We also demonstrate from these analyses that α-activity drives both respiration and cardiac activity.

  6. Invisible Brain: Knowledge in Research Works and Neuron Activity.

    Science.gov (United States)

    Segev, Aviv; Curtis, Dorothy; Jung, Sukhwan; Chae, Suhyun

    2016-01-01

    If the market has an invisible hand, does knowledge creation and representation have an "invisible brain"? While knowledge is viewed as a product of neuron activity in the brain, can we identify knowledge that is outside the brain but reflects the activity of neurons in the brain? This work suggests that the patterns of neuron activity in the brain can be seen in the representation of knowledge-related activity. Here we show that the neuron activity mechanism seems to represent much of the knowledge learned in the past decades based on published articles, in what can be viewed as an "invisible brain" or collective hidden neural networks. Similar results appear when analyzing knowledge activity in patents. Our work also tries to characterize knowledge increase as neuron network activity growth. The results propose that knowledge-related activity can be seen outside of the neuron activity mechanism. Consequently, knowledge might exist as an independent mechanism. PMID:27439199

  7. In-vitro suppression of metabolic activity in malignant human glioblastomas due to pulsed - low frequency electric potential exposures

    Science.gov (United States)

    Schlichting, Abby; Waynant, Ronald W.; Tata, Darrell B.

    2010-02-01

    The role of pulsed - low repetition frequency electric potential was investigated in suppressing the metabolic activities of aggressive human brain cancer cells. Twenty four hours post exposure the glioblastomas were found to be significantly inhibited in their metabolic activity. The findings herein reveal a near complete inhibition of glioblastoma's metabolic activity through selective applications of low frequency pulsed electric potentials.

  8. Inferring brain-computational mechanisms with models of activity measurements

    OpenAIRE

    Kriegeskorte, Nikolaus; Diedrichsen, Jörn

    2016-01-01

    High-resolution functional imaging is providing increasingly rich measurements of brain activity in animals and humans. A major challenge is to leverage such data to gain insight into the brain's computational mechanisms. The first step is to define candidate brain-computational models (BCMs) that can perform the behavioural task in question. We would then like to infer, which of the candidate BCMs best accounts for measured brain-activity data. Here we describe a method that complements each...

  9. 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.

  10. Timing and sequence of brain activity in top-down control of visual-spatial attention.

    OpenAIRE

    Tineke Grent-'t-Jong; Woldorff, Marty G.

    2007-01-01

    Recent brain imaging studies using functional magnetic resonance imaging (fMRI) have implicated a frontal-parietal network in the top-down control of attention. However, little is known about the timing and sequence of activations within this network. To investigate these timing questions, we used event-related electrical brain potentials (ERPs) and a specially designed visual-spatial attentional-cueing paradigm, which were applied as part of a multi-methodological approach that included a cl...

  11. Brain Activity in Response to Visual Symmetry

    Directory of Open Access Journals (Sweden)

    Marco Bertamini

    2014-12-01

    Full Text Available A number of studies have explored visual symmetry processing by measuring event related potentials and neural oscillatory activity. There is a sustained posterior negativity (SPN related to the presence of symmetry. There is also functional magnetic resonance imaging (MRI activity in extrastriate visual areas and in the lateral occipital complex. We summarise the evidence by answering six questions. (1 Is there an automatic and sustained response to symmetry in visual areas? Answer: Yes, and this suggests automatic processing of symmetry. (2 Which brain areas are involved in symmetry perception? Answer: There is an extended network from extrastriate areas to higher areas. (3 Is reflection special? Answer: Reflection is the optimal stimulus for a more general regularity-sensitive network. (4 Is the response to symmetry independent of view angle? Answer: When people classify patterns as symmetrical or random, the response to symmetry is view-invariant. When people attend to other dimensions, the network responds to residual regularity in the image. (5 How are brain rhythms in the two hemispheres altered during symmetry perception? Answer: Symmetry processing (rather than presence produces more alpha desynchronization in the right posterior regions. Finally, (6 does symmetry processing produce positive affect? Answer: Not in the strongest sense, but behavioural measures reveal implicit positive evaluation of abstract symmetry.

  12. Brain activities during synchronized tapping task.

    Science.gov (United States)

    Hiroyasu, Tomoyuki; Murakami, Akiho; Mao Gto; Yokouchi, Hisatake

    2015-08-01

    This study aims to investigate how people process information about other people to determine a response during human-to-human cooperative work. As a preliminary study, the mechanism of cooperative work was examined using interaction between a machine and a human. This machine was designed to have an "other person" model that simulates an emotional model of another person. The task performed in the experiment was a synchronized tapping task. Two models were prepared for this experiment, a simple model that does not employ the other person model and a synchronized model that employs the other person model. Subjects performed cooperative work with these machines. During the experiment, brain activities were measured using functional near-infrared spectroscopy. It was observed that the left inferior frontal gyrus was activated more with the synchronized model than the simple model. PMID:26737670

  13. Brain Activity with Reading Sentences and Emoticons

    Science.gov (United States)

    Yuasa, Masahide; Saito, Keiichi; Mukawa, Naoki

    In this paper, we describe a person's brain activity when he/she sees an emoticon at the end of a sentence. An emoticon consists of some characters that resemble the human face and expresses a sender's emotion. With the help of a computer network, we use e-mail, messenger, avatars and so on, in order to convey what we wish to, to a receiver. Moreover, we send an emotional expression by using an emoticon at the end of a sentence. In this research, we investigate the effect of an emoticon as nonverbal information, using an fMRI study. The experimental results show that the right and left inferior frontal gyrus were activated and we detect a sentence with an emoticon as the verbal and nonverval information.

  14. Electrical Stimulation of the Suprahyoid Muscles in Brain-injured Patients with Dysphagia: A Pilot Study

    OpenAIRE

    Beom, Jaewon; Kim, Sang Jun; Han, Tai Ryoon

    2011-01-01

    Objective To investigate the therapeutic effects of repetitive electrical stimulation of the suprahyoid muscles in brain-injured patients with dysphagia. Method Twenty-eight brain-injured patients who showed reduced laryngeal elevation and supraglottic penetration or subglottic aspiration during a videofluoroscopic swallowing study (VFSS) were selected. The patients received either conventional dysphagia management (CDM) or CDM with repetitive electrical stimulation of the suprahyoid muscles ...

  15. Imaging electrical activity of neurons with metamaterial nanosensors

    CERN Document Server

    Beletskiy, Roman V

    2013-01-01

    A technology for recording electrical activity of large neuron populations at arbitrary depth in brain tissues with less than cell spatial and millisecond temporal resolutions was the most craving dream of neuroscientists and a long pursued goal of engineers for decades. Even though many imaging techniques have been devised up to date, none of them is capable to deliver either quantitatively valid data nor able to meet contradictory requirements posed for sensors to be safe, non-invasive and reliably working either within cultured cell populations or during chronic implantations in vivo. In my research project, I design and justify a novel nanobiosensors, capable to detect and optically report the electric fields across cellular membrane and investigate properties of that specially engineered plasmonic nanoantennas. In the following literature survey, I observe the current state of electrophysiology methods and after recalling the basics of fluorescence, discuss benefits and drawbacks of today's voltage sensi...

  16. Electrically sensing protease activity with nanopores

    Science.gov (United States)

    Kukwikila, Mikiembo; Howorka, Stefan

    2010-11-01

    The enzymatic activity of a protease was electrically detected using nanopore recordings. A peptide substrate was tethered to microscale beads, and cleavage by the enzyme trypsin released a soluble fragment that was electrophoretically driven through the α-hemolysin protein pore, leading to detectable blockades in the ionic current. Owing to its simplicity, this approach to sense enzymatic activity may be applied to other proteases.

  17. 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.

  18. On a Quantum Model of Brain Activities

    Science.gov (United States)

    Fichtner, K.-H.; Fichtner, L.; Freudenberg, W.; Ohya, M.

    2010-01-01

    One of the main activities of the brain is the recognition of signals. A first attempt to explain the process of recognition in terms of quantum statistics was given in [6]. Subsequently, details of the mathematical model were presented in a (still incomplete) series of papers (cf. [7, 2, 5, 10]). In the present note we want to give a general view of the principal ideas of this approach. We will introduce the basic spaces and justify the choice of spaces and operations. Further, we bring the model face to face with basic postulates any statistical model of the recognition process should fulfill. These postulates are in accordance with the opinion widely accepted in psychology and neurology.

  19. Сhanges of brain bioelectric activity by diabetic encephalopathy

    OpenAIRE

    Vitaly P. Omelchenko; Elena A. Timoshenko

    2011-01-01

    This article focuses on the analysis of brain bioelectric activity by diabetic encephalopathy. Paid attention to the establishment of EEG parameters and patients psychological characteristics interrelation.

  20. Antioxidant activity of carnosine, homocarnosine, and anserine present in muscle and brain.

    OpenAIRE

    Kohen, R; Yamamoto, Y.; Cundy, K C; Ames, B N

    1988-01-01

    Carnosine, homocarnosine, and anserine are present in high concentrations in the muscle and brain of many animals and humans. However, their exact function is not clear. The antioxidant activity of these compounds has been examined by testing their peroxyl radical-trapping ability at physiological concentrations. Carnosine, homocarnosine, anserine, and other histidine derivatives all showed antioxidant activity. All of these compounds showing peroxyl radical-trapping activity were also electr...

  1. Electrical Activity in Martian Dust Storms

    Science.gov (United States)

    Majid, W.

    2015-12-01

    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 proposed program 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.

  2. 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.

  3. The effects of physical activity on brain structure

    OpenAIRE

    AdamThomas; PeterABandettini

    2012-01-01

    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 imp...

  4. The atmospheric electric global circuit. [thunderstorm activity

    Science.gov (United States)

    Kasemir, H. W.

    1979-01-01

    The hypothesis that world thunderstorm activity represents the generator for the atmospheric electric current flow in the earth atmosphere between ground and the ionosphere is based on a close correlation between the magnitude and the diurnal variation of the supply current (thunderstorm generator current) and the load current (fair weather air-earth current density integrated over the earth surface). The advantages of using lightning survey satellites to furnish a base for accepting or rejecting the thunderstorm generator hypothesis are discussed.

  5. Finer discrimination of brain activation with local multivariate distance

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The organization of human brain function is diverse on different spatial scales.Various cognitive states are alwavs represented as distinct activity patterns across the specific brain region on fine scales.Conventional univariate analysis of functional MRI data seeks to determine how a particular cognitive state is encoded in brain activity by analyzing each voxel separately without considering the fine-scale patterns information contained in the local brain regions.In this paper,a local multivariate distance mapping(LMDM)technique is proposed to detect the brain activation and to map the fine-scale brain activity patterns.LMDM directly represents the local brain activity with the patterns across multiple voxels rather than individual voxels,and it employs the multivariate distance between different patterns to discriminate the brain state on fine scales.Experiments with simulated and real fMRI data demonstrate that LMDM technique can dramatically increase the sensitivity of the detection for the fine-scale brain activity pettems which contain the subtle information of the experimental conditions.

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

    Institute of Scientific and Technical Information of China (English)

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

    2013-01-01

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

  7. 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.

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

    DEFF Research Database (Denmark)

    Hyldig, Tino Hoffmann

    2001-01-01

    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...

  9. Network-dependent modulation of brain activity during sleep

    OpenAIRE

    Watanabe, T.; Kan, S.; Koike, T.; Misaki, M; Konishi, S.; Miyauchi, S; Miyahsita, Y.; Masuda, N.

    2014-01-01

    Brain activity dynamically changes even during sleep. A line of neuroimaging studies has reported changes in functional connectivity and regional activity across different sleep stages such as slow-wave sleep (SWS) and rapid-eye-movement (REM) sleep. However, it remains unclear whether and how the large-scale network activity of human brains changes within a given sleep stage. Here, we investigated modulation of network activity within sleep stages by applying the pairwise maximum entropy mod...

  10. A reliable method for intracranial electrode implantation and chronic electrical stimulation in the mouse brain

    OpenAIRE

    Jeffrey, Melanie; Lang, Min; Gane, Jonathan; Wu, Chiping; Burnham, W McIntyre; Zhang, Liang

    2013-01-01

    Background Electrical stimulation of brain structures has been widely used in rodent models for kindling or modeling deep brain stimulation used clinically. This requires surgical implantation of intracranial electrodes and subsequent chronic stimulation in individual animals for several weeks. Anchoring screws and dental acrylic have long been used to secure implanted intracranial electrodes in rats. However, such an approach is limited when carried out in mouse models as the thin mouse skul...

  11. 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. PMID:25411452

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

    International Nuclear Information System (INIS)

    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. (paper)

  13. 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

    2014-08-01

    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.

  14. Mapping human brain activity in vivo.

    OpenAIRE

    Mazziotta, J.C.

    1994-01-01

    A wide range of structural and functional techniques now exists to map the human brain in health and disease. These approaches span the gamut from external tomographic imaging devices (positron-emission tomography, single photon-emission computed tomography, magnetic resonance imaging, computed tomography), to surface detectors (electroencephalography, magnetoencephalography, transcranial magnetic stimulation), to measurements made directly on the brain's surface or beneath it (intrinsic sign...

  15. Active microwave computed brain tomography: the response to a challenge.

    Science.gov (United States)

    Almirall, H; Broquetas, A; Jofre, L

    1991-02-01

    The potential application of active microwave techniques to brain imaging is studied by numerical simulations and experimentally using a recently developed cylindrical microwave scanner. The potential advantages and limitations of this method in static and dynamic brain imaging are presented and compared with other imaging techniques. PMID:2062119

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

    Institute of Scientific and Technical Information of China (English)

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

    2009-01-01

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

  17. The Effect of Herrmann Whole Brain Teaching Method on Students' Understanding of Simple Electric Circuits

    Science.gov (United States)

    Bawaneh, Ali Khalid Ali; Nurulazam Md Zain, Ahmad; Salmiza, Saleh

    2011-01-01

    The purpose of this study was to investigate the effect of Herrmann Whole Brain Teaching Method over conventional teaching method on eight graders in their understanding of simple electric circuits in Jordan. Participants (N = 273 students; M = 139, F = 134) were randomly selected from Bani Kenanah region-North of Jordan and randomly assigned to…

  18. 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 ...

  19. 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.

  20. Model of local temperature changes in brain upon functional activation.

    Science.gov (United States)

    Collins, Christopher M; Smith, Michael B; Turner, Robert

    2004-12-01

    Experimental results for changes in brain temperature during functional activation show large variations. It is, therefore, desirable to develop a careful numerical model for such changes. Here, a three-dimensional model of temperature in the human head using the bioheat equation, which includes effects of metabolism, perfusion, and thermal conduction, is employed to examine potential temperature changes due to functional activation in brain. It is found that, depending on location in brain and corresponding baseline temperature relative to blood temperature, temperature may increase or decrease on activation and concomitant increases in perfusion and rate of metabolism. Changes in perfusion are generally seen to have a greater effect on temperature than are changes in metabolism, and hence active brain is predicted to approach blood temperature from its initial temperature. All calculated changes in temperature for reasonable physiological parameters have magnitudes <0.12 degrees C and are well within the range reported in recent experimental studies involving human subjects.

  1. Сhanges of brain bioelectric activity by diabetic encephalopathy

    Directory of Open Access Journals (Sweden)

    Vitaly P. Omelchenko

    2011-05-01

    Full Text Available This article focuses on the analysis of brain bioelectric activity by diabetic encephalopathy. Paid attention to the establishment of EEG parameters and patients psychological characteristics interrelation.

  2. 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.…

  3. Imaging of brain activity by positron emission tomography

    International Nuclear Information System (INIS)

    Brain function is associated with regional energy metabolism and blood flow increase. Such brain activity is visualized by using external scintigraphy. Positron emission tomography (PET) is the currently available most superior technique, allowing three-dimensional imaging of subtle blood flow. In this article, imaging methods and application of PET are discussed in terms of the following items: (1) measurement of cerebral glucose consumption, (2) PET in persons with visual impairment, (3) association between brain function and regional cerebral blood flow, (4) measurement of cerebral blood flow, (5) method for decreasing noise in PET imaging, (6) anatomic standardization of PET images, and (7) speech load and regional cerebral activity images. (N.K.)

  4. Contributions of Glycogen to Astrocytic Energetics during Brain Activation

    OpenAIRE

    Dienel, Gerald A.; Nancy F Cruz

    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 g...

  5. Brain activity patterns uniquely supporting visual feature integration after traumatic brain injury

    Directory of Open Access Journals (Sweden)

    Anjali eRaja Beharelle

    2011-12-01

    Full Text Available Traumatic brain injury (TBI patients typically respond more slowly and with more variability than controls during tasks of attention requiring speeded reaction time. These behavioral changes are attributable, at least in part, to diffuse axonal injury (DAI, which affects integrated processing in distributed systems. Here we use a multivariate method sensitive to distributed neural activity to compare brain activity patterns of patients with chronic phase moderate-to-severe TBI to those of controls during performance on a visual feature-integration task assessing complex attentional processes that has previously shown sensitivity to TBI. The TBI patients were carefully screened to be free of large focal lesions that can affect performance and brain activation independently of DAI. The task required subjects to hold either one or three features of a target in mind while suppressing responses to distracting information. In controls, the multi-feature condition activated a distributed network including limbic, prefrontal, and medial temporal structures. TBI patients engaged this same network in the single-feature and baseline conditions. In multi-feature presentations, TBI patients alone activated additional frontal, parietal, and occipital regions. These results are consistent with neuroimaging studies using tasks assessing different cognitive domains, where increased spread of brain activity changes was associated with TBI. Our results also extend previous findings that brain activity for relatively moderate task demands in TBI patients is similar to that associated with of high task demands in controls.

  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. 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…

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

    Science.gov (United States)

    Li, Kai; Papademetris, Xenophon; Tucker, Don M

    2016-01-01

    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. PMID:27293419

  9. 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.

  10. Integrated electric alternators/active filters

    Science.gov (United States)

    Towliat Abolhassani, Mehdi

    In response to energy crisis and power quality concerns, three different methodologies to integrate the concept of active filtering into the alternators are proposed. Wind energy, due to its free availability and its clean and renewable character, ranks as the most promising renewable energy resource that could play a key role in solving the worldwide energy crisis. An Integrated Doubly-fed Electric Alternator/Active filter (IDEA) for wind energy conversion systems is proposed. The proposed IDEA is capable of simultaneously capturing maximum power of wind energy and improving power quality, which are achieved by canceling the most significant and troublesome harmonics of the utility grid and power factor correction and reactive power compensation in the grid. The back-to-back current regulated power converters are employed to excite the rotor of IDEA. The control strategy of rotor-side power converter is based on position sensorless field oriented control method with higher power density. Analysis and experimental results are presented to demonstrate the effectiveness of the proposed IDEA. In the next step, an integrated synchronous machine/active filter is discussed. The proposed technology is essentially a rotating synchronous machine with suitable modification to its field excitation circuit to allow dc and ac excitations. It is shown that by controlling the ac excitation, the 5 th and 7th harmonics currents of the utility are compensated. The proposed method is cost effective because it can be applied to existing standby generators in commercial and industrial plants with minimal modification to the excitation circuits. To boost the gain of harmonic compensatory, an advanced electric machine is proposed. An Asymmetric Airgap Concentrated Winding Synchronous Machine (AACWSM) with ac and dc excitation was designed and employed. It is shown that the AACWSM with its unique design, in addition to power generation capability, could be used to compensate the most

  11. 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.

  12. 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.

  13. Electrical stimulation of the human brain: perceptual and behavioral phenomena reported in the old and new literature

    Directory of Open Access Journals (Sweden)

    Aslihan Selimbeyoglu

    2010-05-01

    Full Text Available In this review, we summarize the subjective experiential phenomena and behavioral changes that are caused by electrical stimulation of the cerebral cortex or subcortical nuclei in awake and conscious human subjects. Our comprehensive review contains a detailed summary of the data obtained from electrical brain stimulation (EBS in humans in the last 100 years. Findings from the EBS studies may provide an additional layer of information about the neural correlates of cognition and behavior in healthy human subjects, or the neuroanatomy of illusions and hallucinations in patients with psychosis, and the anatomy of seizure signs and symptoms in patients with epilepsy. In addition to a comprehensive overview of published reports in the last hundred years, we discuss some of the fundamental concepts, issues, and remaining questions that have defined the field of EBS. We also review the current state of knowledge about the mechanism of action of EBS suggesting that the modulation of activity within a localized, but distributed, neuroanatomical network might explain the perceptual and behavioral phenomena that are reported during focal electrical stimulation of the human brain.

  14. Active filter to improve the energetic efficiency in electric installations.

    OpenAIRE

    Amarís Duarte, Hortensia; Robles Muñoz, Guillermo

    2009-01-01

    The Department of Electrical Engineering of the University Carlos III of Madrid has developed a prototype of active filter to compensate the disturbances that a nonlinear load produces. The active filters appears like the dynamic solution that best fits to the needs of compensation of electrical disturbances in industrial facilities. This active filter allows correcting the power factor of the installation. With this improvement, electrical consumes are reduced, which results in significa...

  15. Distributed patterns of brain activity that lead to forgetting

    OpenAIRE

    Ilke eOztekin; David eBadre

    2011-01-01

    HUMAN NEUROSCIENCE Distributed patterns of brain activity that lead to forgetting Ilke Öztekin1* and David Badre2,3 1 Department of Psychology, Koç University, Istanbul, Turkey 2 Department of Cognitive, Linguistic and Psychological Sciences, Brown University, Providence, RI, USA 3 Brown Institute for Brain Sciences, Brown University, Providence, RI, USA Proactive interference (PI), in which irrelevant information from prior learning disrupts memory performance, is widely...

  16. Functional Magnetic Resonance Imaging of Electrical and Optogenetic Deep Brain Stimulation at the Rat Nucleus Accumbens

    Science.gov (United States)

    Albaugh, Daniel L.; Salzwedel, Andrew; van den Berge, Nathalie; Gao, Wei; Stuber, Garret D.; Shih, Yen-Yu Ian

    2016-09-01

    Deep brain stimulation of the nucleus accumbens (NAc-DBS) is an emerging therapy for diverse, refractory neuropsychiatric diseases. Although DBS therapy is broadly hypothesized to work through large-scale neural modulation, little is known regarding the neural circuits and networks affected by NAc-DBS. Using a healthy, sedated rat model of NAc-DBS, we employed both evoked- and functional connectivity (fc) MRI to examine the functional circuit and network changes achieved by electrical NAc stimulation. Optogenetic-fMRI experiments were also undertaken to evaluate the circuit modulation profile achieved by selective stimulation of NAc neurons. NAc-DBS directly modulated neural activity within prefrontal cortex and a large number of subcortical limbic areas (e.g., amygdala, lateral hypothalamus), and influenced functional connectivity among sensorimotor, executive, and limbic networks. The pattern and extent of circuit modulation measured by evoked-fMRI was relatively insensitive to DBS frequency. Optogenetic stimulation of NAc cell bodies induced a positive fMRI signal in the NAc, but no other detectable downstream responses, indicating that therapeutic NAc-DBS might exert its effect through antidromic stimulation. Our study provides a comprehensive mapping of circuit and network-level neuromodulation by NAc-DBS, which should facilitate our developing understanding of its therapeutic mechanisms of action.

  17. Functional Magnetic Resonance Imaging of Electrical and Optogenetic Deep Brain Stimulation at the Rat Nucleus Accumbens

    Science.gov (United States)

    Albaugh, Daniel L.; Salzwedel, Andrew; Van Den Berge, Nathalie; Gao, Wei; Stuber, Garret D.; Shih, Yen-Yu Ian

    2016-01-01

    Deep brain stimulation of the nucleus accumbens (NAc-DBS) is an emerging therapy for diverse, refractory neuropsychiatric diseases. Although DBS therapy is broadly hypothesized to work through large-scale neural modulation, little is known regarding the neural circuits and networks affected by NAc-DBS. Using a healthy, sedated rat model of NAc-DBS, we employed both evoked- and functional connectivity (fc) MRI to examine the functional circuit and network changes achieved by electrical NAc stimulation. Optogenetic-fMRI experiments were also undertaken to evaluate the circuit modulation profile achieved by selective stimulation of NAc neurons. NAc-DBS directly modulated neural activity within prefrontal cortex and a large number of subcortical limbic areas (e.g., amygdala, lateral hypothalamus), and influenced functional connectivity among sensorimotor, executive, and limbic networks. The pattern and extent of circuit modulation measured by evoked-fMRI was relatively insensitive to DBS frequency. Optogenetic stimulation of NAc cell bodies induced a positive fMRI signal in the NAc, but no other detectable downstream responses, indicating that therapeutic NAc-DBS might exert its effect through antidromic stimulation. Our study provides a comprehensive mapping of circuit and network-level neuromodulation by NAc-DBS, which should facilitate our developing understanding of its therapeutic mechanisms of action. PMID:27601003

  18. Acupuncture inhibits cue-induced heroin craving and brain activation

    Institute of Scientific and Technical Information of China (English)

    Xinghui Cai; Xiaoge Song; Chuanfu Li; Chunsheng Xu; Xiliang Li; Qi Lu

    2012-01-01

    Previous research using functional MRI has shown that specific brain regions associated with drug dependence and cue-elicited heroin craving are activated by environmental cues.Craving is an important trigger of heroin relapse,and acupuncture may inhibit craving.In this study,we performed functional MRI in heroin addicts and control subjects.We compared differences in brain activation between the two groups during heroin cue exposure,heroin cue exposure plus acupuncture at the Zusanli point(ST36)without twirling of the needle,and heroin cue exposure plus acupuncture at the Zusanli point with twirling of the needle.Heroin cue exposure elicited significant activation in craving-related brain regions mainly in the frontal lobes and callosal gyri.Acupuncture without twirling did not significantly affect the range of brain activation induced by heroin cue exposure,but significantly changed the extent of the activation in the heroin addicts group.Acupuncture at the Zusanli.point with twirling of the needle significantly decreased both the range and extent of activation induced by heroin cue exposure compared with heroin cue exposure plus acupuncture without twirling of the needle.These experimental findings indicate that presentation of heroin cues can induce activation in craving-related brain regions,which are involved in reward,learning and memory,cognition and emotion.Acupuncture at the Zusanli point can rapidly suppress the activation of specific brain regions related to craving,supporting its potential as an intervention for drug craving.

  19. Improving Electrical Impedance Tomography of brain function with a novel servo-controlled electrode helmet

    OpenAIRE

    Avery, J. P.

    2015-01-01

    Electrical Impedance Tomography (EIT) is a medical imaging technique which reconstructs the internal conductivity of an object from boundary measurements. EIT has the potential to provide a novel means of imaging in acute stroke, epilepsy or traumatic brain injury. Previous studies, whilst demonstrating the potential of the technique, have not been successful clinically.The work in this thesis aims to address fundamental limitations including measurement drift in electronic hardware, lack of ...

  20. 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.

  1. Inferring brain-computational mechanisms with models of activity measurements.

    Science.gov (United States)

    Kriegeskorte, Nikolaus; Diedrichsen, Jörn

    2016-10-01

    High-resolution functional imaging is providing increasingly rich measurements of brain activity in animals and humans. A major challenge is to leverage such data to gain insight into the brain's computational mechanisms. The first step is to define candidate brain-computational models (BCMs) that can perform the behavioural task in question. We would then like to infer which of the candidate BCMs best accounts for measured brain-activity data. Here we describe a method that complements each BCM by a measurement model (MM), which simulates the way the brain-activity measurements reflect neuronal activity (e.g. local averaging in functional magnetic resonance imaging (fMRI) voxels or sparse sampling in array recordings). The resulting generative model (BCM-MM) produces simulated measurements. To avoid having to fit the MM to predict each individual measurement channel of the brain-activity data, we compare the measured and predicted data at the level of summary statistics. We describe a novel particular implementation of this approach, called probabilistic representational similarity analysis (pRSA) with MMs, which uses representational dissimilarity matrices (RDMs) as the summary statistics. We validate this method by simulations of fMRI measurements (locally averaging voxels) based on a deep convolutional neural network for visual object recognition. Results indicate that the way the measurements sample the activity patterns strongly affects the apparent representational dissimilarities. However, modelling of the measurement process can account for these effects, and different BCMs remain distinguishable even under substantial noise. The pRSA method enables us to perform Bayesian inference on the set of BCMs and to recognize the data-generating model in each case.This article is part of the themed issue 'Interpreting BOLD: a dialogue between cognitive and cellular neuroscience'.

  2. Inferring brain-computational mechanisms with models of activity measurements.

    Science.gov (United States)

    Kriegeskorte, Nikolaus; Diedrichsen, Jörn

    2016-10-01

    High-resolution functional imaging is providing increasingly rich measurements of brain activity in animals and humans. A major challenge is to leverage such data to gain insight into the brain's computational mechanisms. The first step is to define candidate brain-computational models (BCMs) that can perform the behavioural task in question. We would then like to infer which of the candidate BCMs best accounts for measured brain-activity data. Here we describe a method that complements each BCM by a measurement model (MM), which simulates the way the brain-activity measurements reflect neuronal activity (e.g. local averaging in functional magnetic resonance imaging (fMRI) voxels or sparse sampling in array recordings). The resulting generative model (BCM-MM) produces simulated measurements. To avoid having to fit the MM to predict each individual measurement channel of the brain-activity data, we compare the measured and predicted data at the level of summary statistics. We describe a novel particular implementation of this approach, called probabilistic representational similarity analysis (pRSA) with MMs, which uses representational dissimilarity matrices (RDMs) as the summary statistics. We validate this method by simulations of fMRI measurements (locally averaging voxels) based on a deep convolutional neural network for visual object recognition. Results indicate that the way the measurements sample the activity patterns strongly affects the apparent representational dissimilarities. However, modelling of the measurement process can account for these effects, and different BCMs remain distinguishable even under substantial noise. The pRSA method enables us to perform Bayesian inference on the set of BCMs and to recognize the data-generating model in each case.This article is part of the themed issue 'Interpreting BOLD: a dialogue between cognitive and cellular neuroscience'. PMID:27574316

  3. Radio electric asymmetric brain stimulation in the treatment of behavioral and psychiatric symptoms in Alzheimer disease

    Directory of Open Access Journals (Sweden)

    Mannu P

    2011-07-01

    Full Text Available Piero Mannu1, Salvatore Rinaldi1,2, Vania Fontani1, Alessandro Castagna11Rinaldi Fontani Institute, Department of Neuro Psycho Physio Pathology, Florence, Italy; 2Medical School of Occupational Medicine, University of Florence, Florence, ItalyPurpose: Behavioral and psychiatric symptoms of dementia (BPSD are common in Alzheimer's disease (AD and disrupt the effective management of AD patients. The present study explores the use of radio electric asymmetric brain stimulation (REAC in patients who have had a poor response to pharmacological treatment.Patients and methods: Eight patients (five females and three males; mean [±standard deviation] age at study baseline: 69.9 ± 3.0 years diagnosed with AD according to the DSM-IV-TR criteria (mean onset age of AD: 65.4 ± 3.5 years were cognitively and psychometrically assessed with the Mini-Mental State Examination (MMSE, the Activity of Daily Living (ADL, the Instrumental Activity of Daily Living (IADL, and the Neuropsychiatric Inventory (NPI, prior to and after each of 2 REAC treatment cycles.Results: Scores on the MMSE and all subscales of the NPI (frequency, severity, and distress, the ADL, and the IADL were significantly improved following the initial REAC treatment. There was further significant improvement in all measurements (with a tendency for improvement in the IADL after the second REAC treatment cycle.Conclusion: The improvement of cognitive and behavioral/psychiatric functioning following REAC treatment suggests that this innovative approach may be an effective, safe, and tolerable alternative to pharmacological treatment of AD patients, especially in the area of BPSD. Elderly patients suffering from other types of dementia may also benefit from REAC treatment.Keywords: anxiety, depression, insomnia, behavioral and psychiatric symptoms of dementia (BPSD

  4. What kind of noise is brain noise? Anomalous scaling behavior of the resting brain activity fluctuations.

    Directory of Open Access Journals (Sweden)

    Daniel eFraiman

    2012-07-01

    Full Text Available The study of spontaneous fluctuations of brain activity, often referred as brain noise, is getting increasing attention in functional magnetic resonance imaging (fMRI studies. Despite important efforts, much of the statistical properties of such fluctuations remain largely unknown. This work scrutinize these fluctuations looking at specific statistical properties which are relevant to clarify its dynamical origins. Here, three statistical features which clearly differentiate brain data from naive expectations for random processes are uncovered: First, the variance of the fMRI mean signal as a function of the number of averaged voxels remains constant across a wide range of observed clusters sizes. Second, the anomalous behavior of the variance is originated by bursts of synchronized activity across regions, regardless of their widely different sizes. Finally, the correlation length (i.e., the length at which the correlation strength between two regions vanishes as well as mutual information diverges with the cluster's size considered, such that arbitrarily large clusters exhibit the same collective dynamics than smaller ones. These three properties are known to be exclusive of complex systems exhibiting critical dynamics, where the spatio-temporal dynamics show these peculiar type of fluctuations. Thus, these findings are fully consistent with previous reports of brain critical dynamics, and are relevant for the interpretation of the role of fluctuations and variability in brain function in health and disease.

  5. Electrical Vehicles Activities Around the World

    DEFF Research Database (Denmark)

    Schauer, Gerd; Garcia-Valle, Rodrigo

    2013-01-01

    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...... power electronics, preparations for roll-out, and there is discussion of a variety of electric vehicles manufactured by the car industry. Only recently the results in terms of performance, costs of operation and consumer acceptance were disheartening but now incentive schemes, regulatory frameworks, new...... engine. In the 1990s research and demonstrations intensified and built a good basis for actual development of electrical vehicles. Discussion of the results achieved and lessons learned from millions of kilometers of road testing is worthwhile but in addition to technological developments such as light...

  6. Physical Activity, Brain Plasticity, and Alzheimer’s Disease

    OpenAIRE

    Erickson, Kirk I.; Weinstein, Andrea M.; Lopez, Oscar L.

    2012-01-01

    In this review we summarize the epidemiological, cross-sectional, and interventional studies examining the association between physical activity and brain volume, function, and risk for Alzheimer’s disease. The epidemiological literature provides compelling evidence that greater amounts of physical activity are associated with a reduced risk of dementia in late life. In addition, randomized interventions using neuroimaging tools have reported that participation in physical activity increases ...

  7. The effects of trypsin on rat brain astrocyte activation

    OpenAIRE

    Masoud Fereidoni; Farzaneh Sabouni; Ali Moghimi; Shirin Hosseini

    2013-01-01

    Background Astrocytes are cells within the central nervous system which are activated in a wide spectrum of infections, and autoimmune and neurodegenerative diseases. In pathologic states, they produce inflammatory cytokines, chemokines, and nitric oxide (NO), and sometimes they induce apoptosis. Their protease-activated receptors (PARs) can be activated by proteases, e.g. thrombin and trypsin, which are important in brain inflammation. The current study aimed to investigate the effects of di...

  8. 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 no

  9. Brain monoamine oxidase A activity predicts trait aggression.

    Science.gov (United States)

    Alia-Klein, Nelly; Goldstein, Rita Z; Kriplani, Aarti; Logan, Jean; Tomasi, Dardo; Williams, Benjamin; Telang, Frank; Shumay, Elena; Biegon, Anat; Craig, Ian W; Henn, Fritz; Wang, Gene-Jack; Volkow, Nora D; Fowler, Joanna S

    2008-05-01

    The genetic deletion of monoamine oxidase A (MAO A), an enzyme that breaks down the monoamine neurotransmitters norepinephrine, serotonin, and dopamine, produces aggressive phenotypes across species. Therefore, a common polymorphism in the MAO A gene (MAOA, Mendelian Inheritance in Men database number 309850, referred to as high or low based on transcription in non-neuronal cells) has been investigated in a number of externalizing behavioral and clinical phenotypes. These studies provide evidence linking the low MAOA genotype and violent behavior but only through interaction with severe environmental stressors during childhood. Here, we hypothesized that in healthy adult males the gene product of MAO A in the brain, rather than the gene per se, would be associated with regulating the concentration of brain amines involved in trait aggression. Brain MAO A activity was measured in vivo in healthy nonsmoking men with positron emission tomography using a radioligand specific for MAO A (clorgyline labeled with carbon 11). Trait aggression was measured with the multidimensional personality questionnaire (MPQ). Here we report for the first time that brain MAO A correlates inversely with the MPQ trait measure of aggression (but not with other personality traits) such that the lower the MAO A activity in cortical and subcortical brain regions, the higher the self-reported aggression (in both MAOA genotype groups) contributing to more than one-third of the variability. Because trait aggression is a measure used to predict antisocial behavior, these results underscore the relevance of MAO A as a neurochemical substrate of aberrant aggression. PMID:18463263

  10. Comparison of brain activation to purposefully activate a tool in healthy subjects and brain tumor patients using fMRI

    International Nuclear Information System (INIS)

    The purpose of this study was to determine the functional organization of the human brain involved in tool-manipulation. Blood Oxygen Level Dependent was measured by functional magnetic resonance imaging in seventeen right-handed healthy volunteers and two brain tumor patients during two tool-manipulation tasks: simulated tightening a bolt with a screwdriver (Simulation), and tightening a bolt with a screwdriver (Real). Subjects performed the experiment without watching the tasks. Bilateral pre-supplementary motor areas, bilateral cerebellar posterior lobes, right ventral premotor area, right calcarine sulcus, and cerebellar vermis were activated during Real but not during Simulation tasks in healthy volunteers. In addition, brain tumor patients activated the prefrontal areas. Our results suggest that the human brain mechanisms for tool-manipulation have a neural-network comprised of presupplementary motor area, ventral premotor area, and bilateral cerebellar posterior lobes. In the patients with brain dusfurction diee to tumors, activation at the prefrontal area provided function compensation without motor paralysis. (author)

  11. Task-Driven Activity Reduces the Cortical Activity Space of the Brain: Experiment and Whole-Brain Modeling.

    Science.gov (United States)

    Ponce-Alvarez, Adrián; He, Biyu J; Hagmann, Patric; Deco, Gustavo

    2015-08-01

    How a stimulus or a task alters the spontaneous dynamics of the brain remains a fundamental open question in neuroscience. One of the most robust hallmarks of task/stimulus-driven brain dynamics is the decrease of variability with respect to the spontaneous level, an effect seen across multiple experimental conditions and in brain signals observed at different spatiotemporal scales. Recently, it was observed that the trial-to-trial variability and temporal variance of functional magnetic resonance imaging (fMRI) signals decrease in the task-driven activity. Here we examined the dynamics of a large-scale model of the human cortex to provide a mechanistic understanding of these observations. The model allows computing the statistics of synaptic activity in the spontaneous condition and in putative tasks determined by external inputs to a given subset of brain regions. We demonstrated that external inputs decrease the variance, increase the covariances, and decrease the autocovariance of synaptic activity as a consequence of single node and large-scale network dynamics. Altogether, these changes in network statistics imply a reduction of entropy, meaning that the spontaneous synaptic activity outlines a larger multidimensional activity space than does the task-driven activity. We tested this model's prediction on fMRI signals from healthy humans acquired during rest and task conditions and found a significant decrease of entropy in the stimulus-driven activity. Altogether, our study proposes a mechanism for increasing the information capacity of brain networks by enlarging the volume of possible activity configurations at rest and reliably settling into a confined stimulus-driven state to allow better transmission of stimulus-related information.

  12. Task-Driven Activity Reduces the Cortical Activity Space of the Brain: Experiment and Whole-Brain Modeling.

    Directory of Open Access Journals (Sweden)

    Adrián Ponce-Alvarez

    2015-08-01

    Full Text Available How a stimulus or a task alters the spontaneous dynamics of the brain remains a fundamental open question in neuroscience. One of the most robust hallmarks of task/stimulus-driven brain dynamics is the decrease of variability with respect to the spontaneous level, an effect seen across multiple experimental conditions and in brain signals observed at different spatiotemporal scales. Recently, it was observed that the trial-to-trial variability and temporal variance of functional magnetic resonance imaging (fMRI signals decrease in the task-driven activity. Here we examined the dynamics of a large-scale model of the human cortex to provide a mechanistic understanding of these observations. The model allows computing the statistics of synaptic activity in the spontaneous condition and in putative tasks determined by external inputs to a given subset of brain regions. We demonstrated that external inputs decrease the variance, increase the covariances, and decrease the autocovariance of synaptic activity as a consequence of single node and large-scale network dynamics. Altogether, these changes in network statistics imply a reduction of entropy, meaning that the spontaneous synaptic activity outlines a larger multidimensional activity space than does the task-driven activity. We tested this model's prediction on fMRI signals from healthy humans acquired during rest and task conditions and found a significant decrease of entropy in the stimulus-driven activity. Altogether, our study proposes a mechanism for increasing the information capacity of brain networks by enlarging the volume of possible activity configurations at rest and reliably settling into a confined stimulus-driven state to allow better transmission of stimulus-related information.

  13. 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. PMID:27275375

  14. 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…

  15. 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 othe

  16. 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

  17. Conformable actively multiplexed high-density surface electrode array for brain interfacing

    Science.gov (United States)

    Rogers, John; Kim, Dae-Hyeong; Litt, Brian; Viventi, Jonathan

    2015-01-13

    Provided are methods and devices for interfacing with brain tissue, specifically for monitoring and/or actuation of spatio-temporal electrical waveforms. The device is conformable having a high electrode density and high spatial and temporal resolution. A conformable substrate supports a conformable electronic circuit and a barrier layer. Electrodes are positioned to provide electrical contact with a brain tissue. A controller monitors or actuates the electrodes, thereby interfacing with the brain tissue. In an aspect, methods are provided to monitor or actuate spatio-temporal electrical waveform over large brain surface areas by any of the devices disclosed herein.

  18. Brain

    Science.gov (United States)

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

  19. Neural sensing of electrical activity with stretchable microelectrode arrays.

    Science.gov (United States)

    Yu, Zhe; Graudejus, Oliver; Lacour, Stéphanie P; Wagner, Sigurd; Morrison, Barclay

    2009-01-01

    Sensing neural activity within mechanically active tissues poses particular hurdles because most electrodes are much stiffer than biological tissues. As the tissue deforms, the rigid electrodes may damage the surrounding tissue. The problem is exacerbated when sensing neural activity in experimental models of traumatic brain injury (TBI) which is caused by the rapid and large deformation of brain tissue. We have developed a stretchable microelectrode array (SMEA) that can withstand large elastic deformations (>5% biaxial strain) while continuing to function. The SMEA were fabricated from thin metal conductors patterned on polydimethylsiloxane (PDMS) and encapsulated with a photo-patternable silicone. SMEA were used to record spontaneous activity from brain slice cultures, as well as evoked activity after stimulating through SMEA electrodes. Slices of brain tissue were grown on SMEA in long-term culture and then mechanically injured with our well-characterized in vitro injury model by stretching the SMEA and the adherent culture, which was confirmed by image analysis. Because brain tissue was grown on the substrate-integrated SMEA, post-injury changes in electrophysiological function were normalized to pre-injury function since the SMEA deformed with the tissue and remained in place during mechanical stimulation. The combination of our injury model and SMEA could help elucidate mechanisms responsible for post-traumatic neuronal dysfunction in the quest for TBI therapies. The SMEA may have additional sensing applications in other mechanically active tissues such as peripheral nerve and heart. PMID:19964344

  20. 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.

  1. Altered brain activity for phonological manipulation in dyslexic Japanese children

    Science.gov (United States)

    Yamamoto, Hisako; Oba, Kentaro; Terasawa, Yuri; Moriguchi, Yoshiya; Uchiyama, Hitoshi; Seki, Ayumi; Koeda, Tatsuya; Inagaki, Masumi

    2013-01-01

    Because of unique linguistic characteristics, the prevalence rate of developmental dyslexia is relatively low in the Japanese language. Paradoxically, Japanese children have serious difficulty analysing phonological processes when they have dyslexia. Neurobiological deficits in Japanese dyslexia remain unclear and need to be identified, and may lead to better understanding of the commonality and diversity in the disorder among different linguistic systems. The present study investigated brain activity that underlies deficits in phonological awareness in Japanese dyslexic children using functional magnetic resonance imaging. We developed and conducted a phonological manipulation task to extract phonological processing skills and to minimize the influence of auditory working memory on healthy adults, typically developing children, and dyslexic children. Current experiments revealed that several brain regions participated in manipulating the phonological information including left inferior and middle frontal gyrus, left superior temporal gyrus, and bilateral basal ganglia. Moreover, dyslexic children showed altered activity in two brain regions. They showed hyperactivity in the basal ganglia compared with the two other groups, which reflects inefficient phonological processing. Hypoactivity in the left superior temporal gyrus was also found, suggesting difficulty in composing and processing phonological information. The altered brain activity shares similarity with those of dyslexic children in countries speaking alphabetical languages, but disparity also occurs between these two populations. These are initial findings concerning the neurobiological impairments in dyslexic Japanese children. PMID:24052613

  2. Altered brain activity for phonological manipulation in dyslexic Japanese children.

    Science.gov (United States)

    Kita, Yosuke; Yamamoto, Hisako; Oba, Kentaro; Terasawa, Yuri; Moriguchi, Yoshiya; Uchiyama, Hitoshi; Seki, Ayumi; Koeda, Tatsuya; Inagaki, Masumi

    2013-12-01

    Because of unique linguistic characteristics, the prevalence rate of developmental dyslexia is relatively low in the Japanese language. Paradoxically, Japanese children have serious difficulty analysing phonological processes when they have dyslexia. Neurobiological deficits in Japanese dyslexia remain unclear and need to be identified, and may lead to better understanding of the commonality and diversity in the disorder among different linguistic systems. The present study investigated brain activity that underlies deficits in phonological awareness in Japanese dyslexic children using functional magnetic resonance imaging. We developed and conducted a phonological manipulation task to extract phonological processing skills and to minimize the influence of auditory working memory on healthy adults, typically developing children, and dyslexic children. Current experiments revealed that several brain regions participated in manipulating the phonological information including left inferior and middle frontal gyrus, left superior temporal gyrus, and bilateral basal ganglia. Moreover, dyslexic children showed altered activity in two brain regions. They showed hyperactivity in the basal ganglia compared with the two other groups, which reflects inefficient phonological processing. Hypoactivity in the left superior temporal gyrus was also found, suggesting difficulty in composing and processing phonological information. The altered brain activity shares similarity with those of dyslexic children in countries speaking alphabetical languages, but disparity also occurs between these two populations. These are initial findings concerning the neurobiological impairments in dyslexic Japanese children.

  3. Titanium dioxide nanoparticles decreases activity of rat brain when administered prenatally

    Directory of Open Access Journals (Sweden)

    Nikita Saraswat

    2016-06-01

    Conclusions: We studied the neurobehaviour of progenies, when the drug was administered to rat brain prenatally. The results showed that the titanium dioxide nanoparticles particles have decreased the brain activity of the rat brain by showing decreased brain activity in progenies also. [Int J Basic Clin Pharmacol 2016; 5(3.000: 733-738

  4. 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,…

  5. Sub-millimeter resolution electrical conductivity images of brain tissues using magnetic resonance-based electrical impedance tomography

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Tong In; Jeong, Woo Chul; Sajib, Saurav Z. K.; Kim, Hyung Joong, E-mail: bmekim@khu.ac.kr; Woo, Eung Je [Department of Biomedical Engineering, Kyung Hee University, Yongin 446-701 (Korea, Republic of); Kim, Hyun Bum [Department of East-West Medical Science, Kyung Hee University, Yongin 446-701 (Korea, Republic of); Kyung, Eun Jung [Department of Pharmacology, Chung-Ang University, Seoul 156-756 (Korea, Republic of); Kwon, Oh In [Department of Mathematics, Konkuk University, Seoul 143-701 (Korea, Republic of)

    2015-07-13

    Recent magnetic resonance (MR)-based electrical impedance tomography (MREIT) of in vivo animal and human subjects enabled the imaging of electromagnetic properties, such as conductivity and permittivity, on tissue structure and function with a few millimeter pixel size. At those resolutions, the conductivity contrast might be sufficient to distinguish different tissue type for certain applications. Since the precise measurement of electrical conductivity under the tissue levels can provide alternative information in a wide range of biomedical applications, it is necessary to develop high-resolution MREIT technique to enhance its availability. In this study, we provide the experimental evaluation of sub-millimeter resolution conductivity imaging method using a 3T MR scanner combined with a multi-echo MR pulse sequence, multi-channel RF coil, and phase optimization method. From the phantom and animal imaging results, sub-millimeter resolution exhibited similar signal-to-noise ratio of MR magnitude and noise levels in magnetic flux density comparing to the existing millimeter resolution. The reconstructed conductivity images at sub-millimeter resolution can distinguish different brain tissues with a pixel size as small as 350 μm.

  6. Sub-millimeter resolution electrical conductivity images of brain tissues using magnetic resonance-based electrical impedance tomography

    International Nuclear Information System (INIS)

    Recent magnetic resonance (MR)-based electrical impedance tomography (MREIT) of in vivo animal and human subjects enabled the imaging of electromagnetic properties, such as conductivity and permittivity, on tissue structure and function with a few millimeter pixel size. At those resolutions, the conductivity contrast might be sufficient to distinguish different tissue type for certain applications. Since the precise measurement of electrical conductivity under the tissue levels can provide alternative information in a wide range of biomedical applications, it is necessary to develop high-resolution MREIT technique to enhance its availability. In this study, we provide the experimental evaluation of sub-millimeter resolution conductivity imaging method using a 3T MR scanner combined with a multi-echo MR pulse sequence, multi-channel RF coil, and phase optimization method. From the phantom and animal imaging results, sub-millimeter resolution exhibited similar signal-to-noise ratio of MR magnitude and noise levels in magnetic flux density comparing to the existing millimeter resolution. The reconstructed conductivity images at sub-millimeter resolution can distinguish different brain tissues with a pixel size as small as 350 μm

  7. 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.

  8. 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.

  9. 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.

  10. Relationship between changes of N-methyl-D-aspartate receptor activity and brain edema after brain injury in rats

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective: To investigate the relationship between the changes of N-methyl-D-aspartate (NMDA) receptor activity and brain edema after injury in rats.   Methods: The brain injury models were made by using a free-falling body. The treatment model was induced by means of injecting AP5 into lateral ventricle before brain injury; water contents in brain cortex were measured with dry-wet method; and NMDA receptor activity was detected with a radio ligand binding assay.   Results: The water contents began to increase at 30 minutes and reached the peak at 6 hours after brain injury. The maximal binding (Bmax) of NMDA receptor increased significantly at 15 minutes and reached the peak at 30 minutes, then decreased gradually and had the lowest value 6 hours after brain injury. Followed the treatment with AP5, NMDA receptor activity in the injured brain showed a normal value; and the water contents were lower than that of AP5-free injury group 24 hours after brain injury.   Conclusions: It suggests that excessive activation of NMDA receptor may be one of the most important factors to induce the secondary cerebral impairments, and AP5 may protect the brain from edema after brain injury.

  11. Electrical stimulation therapies for CNS disorders and pain are mediated by competition between different neuronal networks in the brain.

    Science.gov (United States)

    Faingold, Carl L

    2008-11-01

    CNS neuronal networks are known to control normal physiological functions, including locomotion and respiration. Neuronal networks also mediate the pathophysiology of many CNS disorders. Stimulation therapies, including localized brain and vagus nerve stimulation, electroshock, and acupuncture, are proposed to activate "therapeutic" neuronal networks. These therapeutic networks are dormant prior to stimulatory treatments, but when the dormant networks are activated they compete with pathophysiological neuronal networks, disrupting their function. This competition diminishes the disease symptoms, providing effective therapy for otherwise intractable CNS disorders, including epilepsy, Parkinson's disease, chronic pain, and depression. Competition between stimulation-activated therapeutic networks and pathophysiological networks is a major mechanism mediating the therapeutic effects of stimulation. This network interaction is hypothesized to involve competition for "control" of brain regions that contain high proportions of conditional multireceptive (CMR) neurons. CMR regions, including brainstem reticular formation, amygdala, and cerebral cortex, have extensive connections to numerous brain areas, allowing these regions to participate potentially in many networks. The participation of CMR regions in any network is often variable, depending on the conditions affecting the organism, including vigilance states, drug treatment, and learning. This response variability of CMR neurons is due to the high incidence of excitatory postsynaptic potentials that are below threshold for triggering action potentials. These subthreshold responses can be brought to threshold by blocking inhibition or enhancing excitation via the paradigms used in stimulation therapies. Participation of CMR regions in a network is also strongly affected by pharmacological treatments (convulsant or anesthetic drugs) and stimulus parameters (strength and repetition rate). Many studies indicate that

  12. A statistical analysis of electrical cerebral activity

    International Nuclear Information System (INIS)

    The aim of this work was to study the statistical properties of the amplitude of the electroencephalographic signal. The experimental method is described (implantation of electrodes, acquisition and treatment of data). The program of the mathematical analysis is given (calculation of probability density functions, study of stationarity) and the validity of the tests discussed. The results concerned ten rabbits. Trips of EEG were sampled during 40 s. with very short intervals (500 μs). The probability density functions established for different brain structures (especially the dorsal hippocampus) and areas, were compared during sleep, arousal and visual stimulus. Using a Χ2 test, it was found that the Gaussian distribution assumption was rejected in 96.7 per cent of the cases. For a given physiological state, there was no mathematical reason to reject the assumption of stationarity (in 96 per cent of the cases). (author)

  13. Distinct Patterns of Brain Activity Characterise Lexical Activation and Competition in Spoken Word Production

    NARCIS (Netherlands)

    Piai, V.; Roelofs, A.P.A.; Jensen, O.; Schoffelen, J.M.; Bonnefond, M.

    2014-01-01

    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

  14. Brain activation during a social attribution task in adolescents with moderate to severe traumatic brain injury.

    Science.gov (United States)

    Scheibel, Randall S; Newsome, Mary R; Wilde, Elisabeth A; McClelland, Michelle M; Hanten, Gerri; Krawczyk, Daniel C; Cook, Lori G; Chu, Zili D; Vásquez, Ana C; Yallampalli, Ragini; Lin, Xiaodi; Hunter, Jill V; Levin, Harvey S

    2011-01-01

    The ability to make accurate judgments about the mental states of others, sometimes referred to as theory of mind (ToM), is often impaired following traumatic brain injury (TBI), and this deficit may contribute to problems with interpersonal relationships. The present study used an animated social attribution task (SAT) with functional magnetic resonance imaging (fMRI) to examine structures mediating ToM in adolescents with moderate to severe TBI. The study design also included a comparison group of matched, typically developing (TD) adolescents. The TD group exhibited activation within a number of areas that are thought to be relevant to ToM, including the medial prefrontal and anterior cingulate cortex, fusiform gyrus, and posterior temporal and parietal areas. The TBI subjects had significant activation within many of these same areas, but their activation was generally more intense and excluded the medial prefrontal cortex. Exploratory regression analyses indicated a negative relation between ToM-related activation and measures of white matter integrity derived from diffusion tensor imaging, while there was also a positive relation between activation and lesion volume. These findings are consistent with alterations in the level and pattern of brain activation that may be due to the combined influence of diffuse axonal injury and focal lesions.

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

    DEFF Research Database (Denmark)

    Hyldig, Tino Hoffmann

    2001-01-01

    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.......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...

  16. Brain activity correlates with emotional perception induced by dynamic avatars.

    Science.gov (United States)

    Goldberg, Hagar; Christensen, Andrea; Flash, Tamar; Giese, Martin A; Malach, Rafael

    2015-11-15

    An accurate judgment of the emotional state of others is a prerequisite for successful social interaction and hence survival. Thus, it is not surprising that we are highly skilled at recognizing the emotions of others. Here we aimed to examine the neuronal correlates of emotion recognition from gait. To this end we created highly controlled dynamic body-movement stimuli based on real human motion-capture data (Roether et al., 2009). These animated avatars displayed gait in four emotional (happy, angry, fearful, and sad) and speed-matched neutral styles. For each emotional gait and its equivalent neutral gait, avatars were displayed at five morphing levels between the two. Subjects underwent fMRI scanning while classifying the emotions and the emotional intensity levels expressed by the avatars. Our results revealed robust brain selectivity to emotional compared to neutral gait stimuli in brain regions which are involved in emotion and biological motion processing, such as the extrastriate body area (EBA), fusiform body area (FBA), superior temporal sulcus (STS), and the amygdala (AMG). Brain activity in the amygdala reflected emotional awareness: for visually identical stimuli it showed amplified stronger response when the stimulus was perceived as emotional. Notably, in avatars gradually morphed along an emotional expression axis there was a parametric correlation between amygdala activity and emotional intensity. This study extends the mapping of emotional decoding in the human brain to the domain of highly controlled dynamic biological motion. Our results highlight an extensive level of brain processing of emotional information related to body language, which relies mostly on body kinematics. PMID:26220746

  17. Baseline brain activity fluctuations predict somatosensory perception in humans

    OpenAIRE

    Boly, M; Balteau, E.; Schnakers, C; Degueldre, C.; Moonen, G.; Luxen, A.; Phillips, C.; Peigneux, P; Maquet, P; Laureys, S.

    2007-01-01

    In perceptual experiments, within-individual fluctuations in perception are observed across multiple presentations of the same stimuli, a phenomenon that remains only partially understood. Here, by means of thulium–yttrium/aluminum–garnet laser and event-related functional MRI, we tested whether variability in perception of identical stimuli relates to differences in prestimulus, baseline brain activity. Results indicate a positive relationship between conscious perception of low-intensity so...

  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. Anatomical Atlas-Guided Diffuse Optical Tomography of Brain Activation

    OpenAIRE

    Custo, Anna; Boas, David A.; Tsuzuki, Daisuke; Dan, Ippeita; Mesquita, Rickson; Fischl, Bruce; Grimson, W. Eric L.; Wells, Williams

    2009-01-01

    We describe a neuro imaging protocol that utilizes an anatomical atlas of the human head to guide Diffuse optical tomography of human brain activation. The protocol is demonstrated by imaging the hemodynamic response to median nerve stimulation in three healthy subjects, and comparing the images obtained using a head atlas with the images obtained using the subject-specific head anatomy. The results indicate that using the head atlas anatomy it is possible to reconstruct the location of the b...

  20. Regional distribution of SGLT activity in rat brain in vivo

    OpenAIRE

    Yu, Amy S.; Hirayama, Bruce A.; Timbol, Gerald; Liu, Jie; Diez-Sampedro, Ana; Kepe, Vladimir; Satyamurthy, Nagichettiar; Huang, Sung-Cheng; Wright, Ernest M.; Barrio, Jorge R.

    2012-01-01

    Na+-glucose cotransporter (SGLT) mRNAs have been detected in many organs of the body, but, apart from kidney and intestine, transporter expression, localization, and functional activity, as well as physiological significance, remain elusive. Using a SGLT-specific molecular imaging probe, α-methyl-4-deoxy-4-[18F]fluoro-d-glucopyranoside (Me-4-FDG) with ex vivo autoradiography and immunohistochemistry, we mapped in vivo the regional distribution of functional SGLTs in rat brain. Since Me-4-FDG ...

  1. A functional magnetic resonance imaging study of human brain in pain-related areas induced by electrical stimulation with different intensities

    Directory of Open Access Journals (Sweden)

    Yuan Wang

    2010-01-01

    Full Text Available Background: Pain-related studies have mainly been performed through traditional methods, which lack the rigorous analysis of anatomical locations. Functional magnetic resonance imaging (fMRI is a noninvasive method detecting neural activity, and has the ability to precisely locate related activations in vivo. Moreover, few studies have used painful stimulation of changed intensity to investigate relevant functioning nuclei in the human brain. Aim: This study mainly focused on the pain-related activations induced by electrical stimulation with different intensities using fMRI. Furthermore, the electrophysiological characteristics of different pain-susceptible-neurons were analyzed to construct the pain modulatory network, which was corresponding to painful stimulus of changed intensity. Materials and Methods: Twelve volunteers underwent functional scanning receiving different electrical stimulation. The data were collected and analyzed to generate the corresponding functional activation maps and response time curves related to pain. Results: The common activations were mainly located in several specific regions, including the secondary somatosensory cortex (SII, insula, anterior cingulate cortex (ACC, thalamus, and other cerebral regions. Moreover, innocuous electrical stimulation primarily activated the lateral portions of SII and thalamus, as well as the posterior insula, anterior ACC, whereas noxious electrical stimulation primarily activated the medial portions of SII and thalamus, as well as the anterior insula, the posterior ACC, with larger extensions and greater intensities. Conclusion: Several specified cerebral regions displayed different response patterns during electrical stimulation by means of fMRI, which implied that the corresponding pain-susceptible-neurons might process specific aspects of pain. Elucidation of functions on pain-related regions will help to understand the delicate pain modulation of human brain.

  2. How networks communicate: propagation patterns in spontaneous brain activity.

    Science.gov (United States)

    Mitra, Anish; Raichle, Marcus E

    2016-10-01

    Initially regarded as 'noise', spontaneous (intrinsic) activity accounts for a large portion of the brain's metabolic cost. Moreover, it is now widely known that infra-slow (less than 0.1 Hz) spontaneous activity, measured using resting state functional magnetic resonance imaging of the blood oxygen level-dependent (BOLD) signal, is correlated within functionally defined resting state networks (RSNs). However, despite these advances, the temporal organization of spontaneous BOLD fluctuations has remained elusive. By studying temporal lags in the resting state BOLD signal, we have recently shown that spontaneous BOLD fluctuations consist of remarkably reproducible patterns of whole brain propagation. Embedded in these propagation patterns are unidirectional 'motifs' which, in turn, give rise to RSNs. Additionally, propagation patterns are markedly altered as a function of state, whether physiological or pathological. Understanding such propagation patterns will likely yield deeper insights into the role of spontaneous activity in brain function in health and disease.This article is part of the themed issue 'Interpreting blood oxygen level-dependent: a dialogue between cognitive and cellular neuroscience'. PMID:27574315

  3. Brain activation to cocaine cues and motivation/treatment status

    Science.gov (United States)

    Prisciandaro, James J.; McRae-Clark, Aimee L.; Myrick, Hugh; Henderson, Scott; Brady, Kathleen T.

    2012-01-01

    Motivation to change is believed to be a key factor in therapeutic success in substance use disorders; however, the neurobiological mechanisms through which motivation to change impacts decreased substance use remain unclear. Existing research is conflicting, with some investigations supporting decreased and others reporting increased frontal activation to drug cues in individuals seeking treatment for substance use disorders. The present study investigated the relationship between motivation to change cocaine use and cue-elicited brain activity in cocaine-dependent individuals using two conceptualizations of “motivation to change:” 1) current treatment status (i.e., currently receiving vs. not receiving outpatient treatment for cocaine dependence) and 2) self-reported motivation to change substance use, using the Stages of Change Readiness and Treatment Eagerness Scale (SOCRATES; Miller and Tonigan, 1996). Thirty-eight cocaine-dependent individuals (14 currently in treatment) completed a diagnostic assessment and an fMRI cocaine cue-reactivity task. Whole-brain analyses demonstrated that both treatment-seeking and motivated participants had lower activation to cocaine cues in a wide variety of brain regions in the frontal, occipital, temporal, and cingulate cortices relative to non-treatment-seeking and less motivated participants. Future research is needed to explain the mechanism by which treatment and/or motivation impacts neural cue-reactivity, as such work could potentially aid in the development of more effective therapeutic techniques for substance-dependent patients. PMID:22458561

  4. Brain activation to cocaine cues and motivation/treatment status.

    Science.gov (United States)

    Prisciandaro, James J; McRae-Clark, Aimee L; Myrick, Hugh; Henderson, Scott; Brady, Kathleen T

    2014-03-01

    Motivation to change is believed to be a key factor in therapeutic success in substance use disorders; however, the neurobiological mechanisms through which motivation to change impacts decreased substance use remain unclear. Existing research is conflicting, with some investigations supporting decreased and others reporting increased frontal activation to drug cues in individuals seeking treatment for substance use disorders. The present study investigated the relationship between motivation to change cocaine use and cue-elicited brain activity in cocaine-dependent individuals using two conceptualizations of 'motivation to change': (1) current treatment status (i.e. currently receiving versus not receiving outpatient treatment for cocaine dependence) and (2) self-reported motivation to change substance use, using the Stages of Change Readiness and Treatment Eagerness Scale. Thirty-eight cocaine-dependent individuals (14 currently in treatment) completed a diagnostic assessment and an fMRI cocaine cue-reactivity task. Whole-brain analyses demonstrated that both treatment-seeking and motivated participants had lower activation to cocaine cues in a wide variety of brain regions in the frontal, occipital, temporal and cingulate cortices relative to non-treatment-seeking and less motivated participants. Future research is needed to explain the mechanism by which treatment and/or motivation impacts neural cue reactivity, as such work could potentially aid in the development of more effective therapeutic techniques for substance-dependent patients.

  5. Modeling active electrolocation in weakly electric fish

    CERN Document Server

    Ammari, Habib; Garnier, Josselin

    2012-01-01

    In this paper, we provide a mathematical model for the electrolocation in weakly electric fishes. We first investigate the forward complex conductivity problem and derive the approx- imate boundary conditions on the skin of the fish. Then we provide a dipole approximation for small targets away from the fish. Based on this approximation, we obtain a non-iterative location search algorithm using multi-frequency measurements. We present numerical experi- ments to illustrate the performance and the stability of the proposed multi-frequency location search algorithm. Finally, in the case of disk- and ellipse-shaped targets, we provide a method to reconstruct separately the conductivity, the permittivity, and the size of the targets from multi-frequency measurements.

  6. Electric fields of motor and frontal tDCS in a standard brain space: A computer simulation study.

    Science.gov (United States)

    Laakso, Ilkka; Tanaka, Satoshi; Mikkonen, Marko; Koyama, Soichiro; Sadato, Norihiro; Hirata, Akimasa

    2016-08-15

    The electric field produced in the brain is the main physical agent of transcranial direct current stimulation (tDCS). Inter-subject variations in the electric fields may help to explain the variability in the effects of tDCS. Here, we use multiple-subject analysis to study the strength and variability of the group-level electric fields in the standard brain space. Personalized anatomically-accurate models of 62 subjects were constructed from T1- and T2-weighted MRI. The finite-element method was used to computationally estimate the individual electric fields, which were registered to the standard space using surface based registration. Motor cortical and frontal tDCS were modelled for 16 electrode montages. For each electrode montage, the group-level electric fields had a consistent strength and direction in several brain regions, which could also be located at some distance from the electrodes. In other regions, the electric fields were more variable, and thus more likely to produce variable effects in each individual. Both the anode and cathode locations affected the group-level electric fields, both directly under the electrodes and elsewhere. For motor cortical tDCS, the electric fields could be controlled at the group level by moving the electrodes. However, for frontal tDCS, the group-level electric fields were more variable, and the electrode locations had only minor effects on the group average fields. Our results reveal the electric fields and their variability at the group level in the standard brain space, providing insights into the mechanisms of tDCS for plasticity induction. The data are useful for planning, analysing and interpreting tDCS studies. PMID:27188218

  7. 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 activ

  8. 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

    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 activ

  9. 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

  10. 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.

  11. Abdominal surgery activates nesfatin-1 immunoreactive brain nuclei in rats.

    Science.gov (United States)

    Stengel, Andreas; Goebel, Miriam; Wang, Lixin; Taché, Yvette

    2010-02-01

    Abdominal surgery-induced postoperative gastric ileus is well established to induce Fos expression in specific brain nuclei in rats within 2-h after surgery. However, the phenotype of activated neurons has not been thoroughly characterized. Nesfatin-1 was recently discovered in the rat hypothalamus as a new anorexigenic peptide that also inhibits gastric emptying and is widely distributed in rat brain autonomic nuclei suggesting an involvement in stress responses. Therefore, we investigated whether abdominal surgery activates nesfatin-1-immunoreactive (ir) neurons in the rat brain. Two hours after abdominal surgery with cecal palpation under short isoflurane anesthesia or anesthesia alone, rats were transcardially perfused and brains processed for double immunohistochemical labeling of Fos and nesfatin-1. Abdominal surgery, compared to anesthesia alone, induced Fos expression in neurons of the supraoptic nucleus (SON), paraventricular nucleus (PVN), locus coeruleus (LC), Edinger-Westphal nucleus (EW), rostral raphe pallidus (rRPa), nucleus of the solitary tract (NTS) and ventrolateral medulla (VLM). Double Fos/nesfatin-1 labeling showed that of the activated cells, 99% were nesfatin-1-immunoreactive in the SON, 91% in the LC, 82% in the rRPa, 74% in the EW and VLM, 71% in the anterior parvicellular PVN, 47% in the lateral magnocellular PVN, 41% in the medial magnocellular PVN, 14% in the NTS and 9% in the medial parvicellular PVN. These data established nesfatin-1 immunoreactive neurons in specific nuclei of the hypothalamus and brainstem as part of the neuronal response to abdominal surgery and suggest a possible implication of nesfatin-1 in the alterations of food intake and gastric transit associated with such a stressor. PMID:19944727

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

    DEFF Research Database (Denmark)

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

    2016-01-01

    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.ResultsThe SPD group exhibited significant functional underactivation in a cluster encompassing...... bilateral dorsal striatum (maximal in right caudate), bilateral anterior cingulate and right medial frontal regions. These abnormalities were, for the most part, outside the dorsal planning network typically activated by executive planning tasks.ConclusionsAbnormalities of neural regions involved in habit...

  13. 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.

  14. Electric Current Systems in Solar Active Regions

    Science.gov (United States)

    LaBonte, B. J.; Mickey, D. L.

    2000-05-01

    The first study to show the persistence of local field-aligned current systems in active regions was reported by Pevtsov, Canfield, and Metcalf (Astrophys. J., 425, L117, 1994). Their work was limited to a sample of complex, flare-productive regions because of the sensitivity limit of the data from the Haleakala Stokes Polarimeter. I report here on a new survey of active regions with the Imaging Vector Magnetograph (IVM) at Mees Solar Observatory. The IVM data permit a look at current systems in simpler, more typical active regions, because of better sensitivity, temporal sampling, spatial resolution and field-of-view. Small scale current systems are commonly seen. Transport of current systems by advective processes is commonly seen over times of hours. This work was supported by NASA grant NAG5-4941 and by a subcontract with LMSAL in support of NASA contract NAS8-40801 for YOHKOH SXT.

  15. Reduced brain activation in violent adolescents during response inhibition.

    Science.gov (United States)

    Qiao, Yi; Mei, Yi; Du, XiaoXia; Xie, Bin; Shao, Yang

    2016-01-01

    Deficits in inhibitory control have been linked to aggression and violent behaviour. This study aimed to observe whether violent adolescents show different brain activation patterns during response inhibition and to ascertain the roles these brain regions play. A self-report method and modified overt aggression scale (MOAS) were used to evaluate violent behaviour. Functional magnetic resonance imaging was performed in 22 violent adolescents and 17 matched healthy subjects aged 12 to 18 years. While scanning, a go/no-go task was performed. Between-group comparisons revealed that activation in the bilateral middle and superior temporal gyrus, hippocampus, and right orbitofrontal area (BA11) regions were significantly reduced in the violent group compared with the control group. Meanwhile, the violent group had more widespread activation in the prefrontal cortex than that observed in the control group. Activation of the prefrontal cortex in the violent group was widespread but lacking in focus, failing to produce intensive activation in some functionally related regions during response inhibition. PMID:26888566

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

    OpenAIRE

    Dowrick, T.; Blochet, C.; Holder, D

    2015-01-01

    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 spect...

  17. 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...

  18. 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......-existing Temperament and Character Inventory (TCI) scores. A total of 22 subjects free of psychiatric and somatic disorders were included in the matched high- and low-HA groups. The main outcome measure was regional 5-HTT binding potential (BPND) in high- and low-HA groups estimated with PET and [11C]N,N-dimethyl-2......-(2-amino-4-methylphenylthio)benzylamine ([11C]MADAM). In secondary analyses, 5-HTT BPND was correlated with other TCI dimensions....

  19. Source localization of brain activity using helium-free interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Dammers, Jürgen, E-mail: J.Dammers@fz-juelich.de; Chocholacs, Harald; Eich, Eberhard; Boers, Frank [Institute of Neuroscience and Medicine (INM-4), Forschungszentrum Jülich, Jülich (Germany); Faley, Michael; Dunin-Borkowski, Rafal E. [Peter Grünberg Institute (PGI-5), Forschungszentrum Jülich, Jülich (Germany); Jon Shah, N. [Institute of Neuroscience and Medicine (INM-4), Forschungszentrum Jülich, Jülich (Germany); Department of Neurology, RWTH Aachen University, Aachen (Germany); Jülich Aachen Research Alliance (JARA)—Translational Brain Medicine, Jülich (Germany)

    2014-05-26

    To detect extremely small magnetic fields generated by the human brain, currently all commercial magnetoencephalography (MEG) systems are equipped with low-temperature (low-T{sub c}) superconducting quantum interference device (SQUID) sensors that use liquid helium for cooling. The limited and increasingly expensive supply of helium, which has seen dramatic price increases recently, has become a real problem for such systems and the situation shows no signs of abating. MEG research in the long run is now endangered. In this study, we report a MEG source localization utilizing a single, highly sensitive SQUID cooled with liquid nitrogen only. Our findings confirm that localization of neuromagnetic activity is indeed possible using high-T{sub c} SQUIDs. We believe that our findings secure the future of this exquisitely sensitive technique and have major implications for brain research and the developments of cost-effective multi-channel, high-T{sub c} SQUID-based MEG systems.

  20. Source localization of brain activity using helium-free interferometer

    Science.gov (United States)

    Dammers, Jürgen; Chocholacs, Harald; Eich, Eberhard; Boers, Frank; Faley, Michael; Dunin-Borkowski, Rafal E.; Jon Shah, N.

    2014-05-01

    To detect extremely small magnetic fields generated by the human brain, currently all commercial magnetoencephalography (MEG) systems are equipped with low-temperature (low-Tc) superconducting quantum interference device (SQUID) sensors that use liquid helium for cooling. The limited and increasingly expensive supply of helium, which has seen dramatic price increases recently, has become a real problem for such systems and the situation shows no signs of abating. MEG research in the long run is now endangered. In this study, we report a MEG source localization utilizing a single, highly sensitive SQUID cooled with liquid nitrogen only. Our findings confirm that localization of neuromagnetic activity is indeed possible using high-Tc SQUIDs. We believe that our findings secure the future of this exquisitely sensitive technique and have major implications for brain research and the developments of cost-effective multi-channel, high-Tc SQUID-based MEG systems.

  1. Brain potentials evoked by intraepidermal electrical stimuli reflect the central sensitization of nociceptive pathways

    OpenAIRE

    Liang, M.; Lee, M. C.; O'Neill, J.; Dickenson, A.H.; Iannetti, G.D.

    2016-01-01

    Central sensitization (CS), the increased sensitivity of the central nervous system to somatosensory inputs, accounts for secondary hyperalgesia, a typical sign of several painful clinical conditions. Brain potentials elicited by mechanical punctate stimulation using flat-tip probes can provide neural correlates of CS, but their signal-to-noise ratio is limited by poor synchronisation of the afferent nociceptive input. Additionally, mechanical punctate stimulation does not activate nociceptor...

  2. 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

  3. Seizures, refractory status epilepticus, and depolarization block as endogenous brain activities

    Science.gov (United States)

    El Houssaini, Kenza; Ivanov, Anton I.; Bernard, Christophe; Jirsa, Viktor K.

    2015-01-01

    Epilepsy, refractory status epilepticus, and depolarization block are pathological brain activities whose mechanisms are poorly understood. Using a generic mathematical model of seizure activity, we show that these activities coexist under certain conditions spanning the range of possible brain activities. We perform a detailed bifurcation analysis and predict strategies to escape from some of the pathological states. Experimental results using rodent data provide support of the model, highlighting the concept that these pathological activities belong to the endogenous repertoire of brain activities.

  4. Trans3D: a free tool for dynamical visualization of EEG activity transmission in the brain.

    Science.gov (United States)

    Blinowski, Grzegorz; Kamiński, Maciej; Wawer, Dariusz

    2014-08-01

    The problem of functional connectivity in the brain is in the focus of attention nowadays, since it is crucial for understanding information processing in the brain. A large repertoire of measures of connectivity have been devised, some of them being capable of estimating time-varying directed connectivity. Hence, there is a need for a dedicated software tool for visualizing the propagation of electrical activity in the brain. To this aim, the Trans3D application was developed. It is an open access tool based on widely available libraries and supporting both Windows XP/Vista/7(™), Linux and Mac environments. Trans3D can create animations of activity propagation between electrodes/sensors, which can be placed by the user on the scalp/cortex of a 3D model of the head. Various interactive graphic functions for manipulating and visualizing components of the 3D model and input data are available. An application of the Trans3D tool has helped to elucidate the dynamics of the phenomena of information processing in motor and cognitive tasks, which otherwise would have been very difficult to observe. Trans3D is available at: http://www.eeg.pl/.

  5. 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.

  6. Resuscitation therapy for traumatic brain injury-induced coma in rats: mechanisms of median nerve electrical stimulation

    Directory of Open Access Journals (Sweden)

    Zhen Feng

    2015-01-01

    Full Text Available In this study, rats were put into traumatic brain injury-induced coma and treated with median nerve electrical stimulation. We explored the wake-promoting effect, and possible mechanisms, of median nerve electrical stimulation. Electrical stimulation upregulated the expression levels of orexin-A and its receptor OX1R in the rat prefrontal cortex. Orexin-A expression gradually increased with increasing stimulation, while OX1R expression reached a peak at 12 hours and then decreased. In addition, after the OX1R antagonist, SB334867, was injected into the brain of rats after traumatic brain injury, fewer rats were restored to consciousness, and orexin-A and OXIR expression in the prefrontal cortex was downregulated. Our findings indicate that median nerve electrical stimulation induced an up-regulation of orexin-A and OX1R expression in the prefrontal cortex of traumatic brain injury-induced coma rats, which may be a potential mechanism involved in the wake-promoting effects of median nerve electrical stimulation.

  7. Resuscitation therapy for traumatic brain injury-induced coma in rats:mechanisms of median nerve electrical stimulation

    Institute of Scientific and Technical Information of China (English)

    Zhen Feng; Ying-jun Zhong; Liang Wang; Tian-qi Wei

    2015-01-01

    In this study, rats were put into traumatic brain injury-induced coma and treated with median nerve electrical stimulation. We explored the wake-promoting effect, and possible mechanisms, of median nerve electrical stimulation. Electrical stimulation upregulated the expression levels of orexin-A and its receptor OX1R in the rat prefrontal cortex. Orexin-A expression gradually in-creased with increasing stimulation, while OX1R expression reached a peak at 12 hours and then decreased. In addition, after the OX1R antagonist, SB334867, was injected into the brain of rats after traumatic brain injury, fewer rats were restored to consciousness, and orexin-A and OXIR expression in the prefrontal cortex was downregulated. Our ifndings indicate that median nerve electrical stimulation induced an up-regulation of orexin-A and OX1R expression in the pre-frontal cortex of traumatic brain injury-induced coma rats, which may be a potential mechanism involved in the wake-promoting effects of median nerve electrical stimulation.

  8. 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. PMID:25571015

  9. Brain Activity Associated with Emoticons: An fMRI Study

    Science.gov (United States)

    Yuasa, Masahide; Saito, Keiichi; Mukawa, Naoki

    In this paper, we describe that brain activities associated with emoticons by using fMRI. In communication over a computer network, we use abstract faces such as computer graphics (CG) avatars and emoticons. These faces convey users' emotions and enrich their communications. However, the manner in which these faces influence the mental process is as yet unknown. The human brain may perceive the abstract face in an entirely different manner, depending on its level of reality. We conducted an experiment using fMRI in order to investigate the effects of emoticons. The results show that right inferior frontal gyrus, which associated with nonverbal communication, is activated by emoticons. Since the emoticons were created to reflect the real human facial expressions as accurately as possible, we believed that they would activate the right fusiform gyrus. However, this region was not found to be activated during the experiment. This finding is useful in understanding how abstract faces affect our behaviors and decision-making in communication over a computer network.

  10. An electrically-activated dynamic tissue-equivalent phantom for assessment of diffuse optical imaging systems

    Energy Technology Data Exchange (ETDEWEB)

    Hebden, Jeremy C; Brunker, Joanna; Correia, Teresa; Price, Ben D; Gibson, Adam P; Everdell, N L [Department of Medical Physics and Bioengineering, University College London, Gower Street, London WC1E 6BT (United Kingdom)

    2008-01-21

    A novel design of solid dynamic phantom with tissue-like optical properties is presented, which contains variable regions of contrast which are activated electrically. Reversible changes in absorption are produced by localized heating of targets impregnated with thermochromic pigment. A portable, battery-operated prototype has been constructed, and its optical and temporal characteristics have been investigated. The phantom has been developed as a means of assessing the performance of diffuse optical imaging systems, such as those used to monitor haemodynamic changes in the brain and other tissues. Images of the phantom have been reconstructed using data acquired with a continuous wave optical topography system.

  11. An electrically-activated dynamic tissue-equivalent phantom for assessment of diffuse optical imaging systems

    Science.gov (United States)

    Hebden, Jeremy C.; Brunker, Joanna; Correia, Teresa; Price, Ben D.; Gibson, Adam P.; Everdell, N. L.

    2008-01-01

    A novel design of solid dynamic phantom with tissue-like optical properties is presented, which contains variable regions of contrast which are activated electrically. Reversible changes in absorption are produced by localized heating of targets impregnated with thermochromic pigment. A portable, battery-operated prototype has been constructed, and its optical and temporal characteristics have been investigated. The phantom has been developed as a means of assessing the performance of diffuse optical imaging systems, such as those used to monitor haemodynamic changes in the brain and other tissues. Images of the phantom have been reconstructed using data acquired with a continuous wave optical topography system.

  12. Electrical stimulation of the brain and the development of cortical visual prostheses: An historical perspective.

    Science.gov (United States)

    Lewis, Philip M; Rosenfeld, Jeffrey V

    2016-01-01

    Rapid advances are occurring in neural engineering, bionics and the brain-computer interface. These milestones have been underpinned by staggering advances in micro-electronics, computing, and wireless technology in the last three decades. Several cortically-based visual prosthetic devices are currently being developed, but pioneering advances with early implants were achieved by Brindley followed by Dobelle in the 1960s and 1970s. We have reviewed these discoveries within the historical context of the medical uses of electricity including attempts to cure blindness, the discovery of the visual cortex, and opportunities for cortex stimulation experiments during neurosurgery. Further advances were made possible with improvements in electrode design, greater understanding of cortical electrophysiology and miniaturisation of electronic components. Human trials of a new generation of prototype cortical visual prostheses for the blind are imminent. This article is part of a Special Issue entitled Hold Item. PMID:26348986

  13. MRI findings of the brain in high-voltage electrical burn patient: case report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Cheung Sook; Hong, Sung Hwan; Lee, Myung Joon; Cho, Seong Whi; Lee, Eil Seong; Kang, Ik Won [Hallym University College of Medicine, Seoul (Korea, Republic of)

    2003-05-01

    We report the delayed sequelae arising in a case of electrical injury, reviewing the literature on the subject and focusing on the MRI findings of the brain. A 23-year-old male suffered burns to the left parietal scalp, both feet, and the anterior chest wall. Neurological symptoms and MRI abnormalities appeared 14 days after the insult and continued for about three months. T1-weight MR images demonstrated homogeneous hypointensity, while T2-weighted images depicted hyperintense finger-like projections. Contrast-enhanced T1-weighted images demonstrated strong band-like enhancement, indicating meningeal hyperemia. Follow-up MR imaging showed that the lesion had disappeared, indicating that the cerebral edema and meaningeal hyperemia were reversible.

  14. 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 of cort...

  15. Metabolic and electric brain patterns during pleasant and unpleasant emotions induced by music masterpieces.

    Science.gov (United States)

    Flores-Gutiérrez, Enrique O; Díaz, José-Luís; Barrios, Fernando A; Favila-Humara, Rafael; Guevara, Miguel Angel; del Río-Portilla, Yolanda; Corsi-Cabrera, María

    2007-07-01

    Brain correlates comparing pleasant and unpleasant states induced by three dissimilar masterpiece excerpts were obtained. Related emotional reactions to the music were studied using Principal Component Analysis of validated reports, fMRI, and EEG coherent activity. A piano selection by Bach and a symphonic passage from Mahler widely differing in musical features were used as pleasing pieces. A segment by Prodromidès was used as an unpleasing stimulus. Ten consecutive 30 s segments of each piece alternating with random static noise were played to 19 non-musician volunteers for a total of 30 min of auditory stimulation. Both brain approaches identified a left cortical network involved with pleasant feelings (Bach and Mahler vs. Prodromidès) including the left primary auditory area, posterior temporal, inferior parietal and prefrontal regions. While the primary auditory zone may provide an early affective quality, left cognitive areas may contribute to pleasant feelings when melodic sequences follow expected rules. In contrast, unpleasant emotions (Prodromidès vs. Bach and Mahler) involved the activation of the right frontopolar and paralimbic areas. Left activation with pleasant and right with unpleasant musical feelings is consistent with right supremacy in novel situations and left in predictable processes. When all musical excerpts were jointly compared to noise, in addition to bilateral auditory activation, the left temporal pole, inferior frontal gyrus, and frontopolar area were activated suggesting that cognitive and language processes were recruited in general responses to music. Sensory and cognitive integration seems required for musical emotion.

  16. Investigating the physiology of brain activation with MRI

    Science.gov (United States)

    Buxton, Richard B.; Uludag, Kamil; Dubowitz, David J.

    2004-04-01

    Functional magnetic resonance imaging (fMRI) has become a powerful tool for investigating the working human brain based on the blood oxygenation level dependent (BOLD) effect on the MR signal. However, despite the widespread use of fMRI techniques for mapping brain activation, the basic physiological mechanisms underlying the observed signal changes are still poorly understood. Arterial spin labeling (ASL) techniques, which measure cerebral blood flow (CBF) and the BOLD effect simultaneously, provide a useful tool for investigating these physiological questions. In this paper, recent results of studies manipulating the baseline CBF both pharmacologically and physiologically will be discussed. These data are consistent with a feed-forward mechanism of neurovascular coupling, and suggest that the CBF change itself may be a more robust reflection of neural activity changes than the BOLD effect. Consistent with these data, a new thermodynamic hypothesis is proposed for the physiological function of CBF regulation: maintenance of the [O2]/[CO2] concentration ratio at the mitochondria in order to preserve the free energy available from oxidative metabolism. A kinetic model based on this hypothesis provides a reasonable quantitative description of the CBF changes associated with neural activity and altered blood gases (CO2 and O2).

  17. 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.

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

    Science.gov (United States)

    Sajib, Saurav Z. K.; Jeong, Woo Chul; Kyung, Eun Jung; Kim, Hyun Bum; Oh, Tong In; Kim, Hyung Joong; Kwon, Oh In; Woo, Eung Je

    2016-06-01

    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.

  19. Schizotypal perceptual aberrations of time: correlation between score, behavior and brain activity.

    Directory of Open Access Journals (Sweden)

    Shahar Arzy

    Full Text Available A fundamental trait of the human self is its continuum experience of space and time. Perceptual aberrations of this spatial and temporal continuity is a major characteristic of schizophrenia spectrum disturbances--including schizophrenia, schizotypal personality disorder and schizotypy. We have previously found the classical Perceptual Aberration Scale (PAS scores, related to body and space, to be positively correlated with both behavior and temporo-parietal activation in healthy participants performing a task involving self-projection in space. However, not much is known about the relationship between temporal perceptual aberration, behavior and brain activity. To this aim, we composed a temporal Perceptual Aberration Scale (tPAS similar to the traditional PAS. Testing on 170 participants suggested similar performance for PAS and tPAS. We then correlated tPAS and PAS scores to participants' performance and neural activity in a task of self-projection in time. tPAS scores correlated positively with reaction times across task conditions, as did PAS scores. Evoked potential mapping and electrical neuroimaging showed self-projection in time to recruit a network of brain regions at the left anterior temporal cortex, right temporo-parietal junction, and occipito-temporal cortex, and duration of activation in this network positively correlated with tPAS and PAS scores. These data demonstrate that schizotypal perceptual aberrations of both time and space, as reflected by tPAS and PAS scores, are positively correlated with performance and brain activation during self-projection in time in healthy individuals along the schizophrenia spectrum.

  20. 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.

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

    International Nuclear Information System (INIS)

    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. (paper)

  2. Brain areas activated by uncertain reward-based decision-making in healthy volunteers

    OpenAIRE

    Guo, Zongjun; Chen, Juan; Liu, Shien; Li, Yuhuan; Sun, Bo; Gao, Zhenbo

    2013-01-01

    Reward-based decision-making has been found to activate several brain areas, including the ventrolateral prefrontal lobe, orbitofrontal cortex, anterior cingulate cortex, ventral striatum, and mesolimbic dopaminergic system. In this study, we observed brain areas activated under three degrees of uncertainty in a reward-based decision-making task (certain, risky, and ambiguous). The tasks were presented using a brain function audiovisual stimulation system. We conducted brain scans of 15 healt...

  3. Secondary hyperalgesia phenotypes exhibit differences in brain activation during noxious stimulation

    DEFF Research Database (Denmark)

    Asghar, Mohammad Sohail; Pereira, Manuel Pedro; Werner, Mads Utke;

    2015-01-01

    Noxious stimulation of the skin with either chemical, electrical or heat stimuli leads to the development of primary hyperalgesia at the site of injury, and to secondary hyperalgesia in normal skin surrounding the injury. Secondary hyperalgesia is inducible in most individuals and is attributed....... To study differences in the propensity to develop central sensitization we examined differences in brain activity and anatomy according to individual phenotypical expression of secondary hyperalgesia by magnetic resonance imaging. Forty healthy volunteers received a first-degree burn-injury (47 °C, 7 min......, 9 cm(2)) on the non-dominant lower-leg. Areas of secondary hyperalgesia were assessed 100 min after the injury. We measured neuronal activation by recording blood-oxygen-level-dependent-signals (BOLD-signals) during mechanical noxious stimulation before burn injury and in both primary and secondary...

  4. The effects of trypsin on rat brain astrocyte activation.

    Directory of Open Access Journals (Sweden)

    Masoud Fereidoni

    2013-12-01

    Full Text Available Astrocytes are cells within the central nervous system which are activated in a wide spectrum of infections, and autoimmune and neurodegenerative diseases. In pathologic states, they produce inflammatory cytokines, chemokines, and nitric oxide (NO, and sometimes they induce apoptosis. Their protease-activated receptors (PARs can be activated by proteases, e.g. thrombin and trypsin, which are important in brain inflammation. The current study aimed to investigate the effects of different concentrations of trypsin (1 to 100U/ml on cultured astrocytes.In the present study, two-day rat infants' brains were isolated and homogenized after meninges removal, then cultivated in DMEM + 10% FBS medium. 10 days later, astrocytes were harvested and recultivated for more purification (up to 95%, using Immunocytochemistry method, in order to be employed for tests. They were affected by different concentrations of trypsin (1, 5, 10, 15, 20, 40, 60, 80, and 100 U/ml. To reveal the inflammation progress, NO concentrations (the Griess test were assessed after 24 and 48 hours.The results showed that trypsin concentration up to 20 U/ml caused a significant increase in NO, in a dose-dependent manner, on cultured astrocytes (P < 0.001. Trypsin 20 U/ml increased NO production fivefold the control group (P < 0.001. At higher concentrations than 20 U/ml, NO production diminished (P < 0.001. At 100 U/ml, NO production was less than the control group (P < 0.001.Inflammatory effects of trypsin 5-20 U/ml are probably due to the stimulation of astrocytes' PAR-2 receptors and the increasing of the activation of NF-κB, PKC, MAPKs. Stimulation of astrocytes' PAR-2 receptors causes an increase in iNOS activation which in turn leads to NO production. However, higher trypsin concentration possibly made astrocyte apoptosis; therefore, NO production diminished. These assumptions need to be further investigated.

  5. 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...

  6. Brain electric stimulation in treatment of epilepsy%神经电刺激技术在癫痫治疗中的应用

    Institute of Scientific and Technical Information of China (English)

    杨辉

    2012-01-01

    The treatment of patients with refractory epilepsy has always been challenging. Despite the availability of multiple antiepileptic drugs, approximately 20% - 30% of patients continue to have seizures, and many are not candidates for epilepsy surgery. Currently available treatment options for these unfortunate patients are limited. Brain electric stimulation provides a nondestructive treatment for these patients. Studies of electrical stimulation of the brain in epilepsy treatment begin with the research on cerebellar stimulation. Until now, the potential targets have increased over the years, including cortex, cranial nerve and multiple brain nuclei. With the development of therapeutic brain devices for epilepsy, it is convinced that the brain electric stimulation will become more widely applied in treatment of epilepsy. This overview, combining with literatures and our experiences, briefly summarizes the application of brain electric stimulation in the treatment of epilepsy.

  7. 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. PMID:26006171

  8. Spatiotemporal characteristics of electrocortical brain activity during mental calculation.

    Science.gov (United States)

    Vansteensel, Mariska J; Bleichner, Martin G; Freudenburg, Zac V; Hermes, Dora; Aarnoutse, Erik J; Leijten, Frans S S; Ferrier, Cyrille H; Jansma, Johan Martijn; Ramsey, Nick F

    2014-12-01

    Mental calculation is a complex mental procedure involving a frontoparietal network of brain regions. Functional MRI (fMRI) studies have revealed interesting characteristics of these regions, but the precise function of some areas remains elusive. In the present study, we used electrocorticographic (ECoG) recordings to chronometrically assess the neuronal processes during mental arithmetic. A calculation task was performed during presurgical 3T fMRI scanning and subsequent ECoG monitoring. Mental calculation induced an increase in fMRI blood oxygen level dependent signal in prefrontal, parietal and lower temporo-occipital regions. The group-fMRI result was subsequently used to cluster the implanted electrodes into anatomically defined regions of interest (ROIs). We observed remarkable differences in high frequency power profiles between ROIs, some of which were closely associated with stimulus presentation and others with the response. Upon stimulus presentation, occipital areas were the first to respond, followed by parietal and frontal areas, and finally by motor areas. Notably, we demonstrate that the fMRI activation in the middle frontal gyrus/precentral gyrus is associated with two subfunctions during mental calculation. This finding reveals the significance of the temporal dynamics of neural ensembles within regions with an apparent uniform function. In conclusion, our results shed more light on the spatiotemporal aspects of brain activation during a mental calculation task, and demonstrate that the use of fMRI data to cluster ECoG electrodes is a useful approach for ECoG group analysis. PMID:25044370

  9. Natural image classification driven by human brain activity

    Science.gov (United States)

    Zhang, Dai; Peng, Hanyang; Wang, Jinqiao; Tang, Ming; Xue, Rong; Zuo, Zhentao

    2016-03-01

    Natural image classification has been a hot topic in computer vision and pattern recognition research field. Since the performance of an image classification system can be improved by feature selection, many image feature selection methods have been developed. However, the existing supervised feature selection methods are typically driven by the class label information that are identical for different samples from the same class, ignoring with-in class image variability and therefore degrading the feature selection performance. In this study, we propose a novel feature selection method, driven by human brain activity signals collected using fMRI technique when human subjects were viewing natural images of different categories. The fMRI signals associated with subjects viewing different images encode the human perception of natural images, and therefore may capture image variability within- and cross- categories. We then select image features with the guidance of fMRI signals from brain regions with active response to image viewing. Particularly, bag of words features based on GIST descriptor are extracted from natural images for classification, and a sparse regression base feature selection method is adapted to select image features that can best predict fMRI signals. Finally, a classification model is built on the select image features to classify images without fMRI signals. The validation experiments for classifying images from 4 categories of two subjects have demonstrated that our method could achieve much better classification performance than the classifiers built on image feature selected by traditional feature selection methods.

  10. Integrated Brain Circuits: Astrocytic Networks Modulate Neuronal Activity and Behavior

    Science.gov (United States)

    Halassa, Michael M.; Haydon, Philip G.

    2011-01-01

    The past decade has seen an explosion of research on roles of neuron-astrocyte interactions in the control of brain function. We highlight recent studies performed on the tripartite synapse, the structure consisting of pre- and postsynaptic elements of the synapse and an associated astrocytic process. Astrocytes respond to neuronal activity and neuro-transmitters, through the activation of metabotropic receptors, and can release the gliotransmitters ATP, D-serine, and glutamate, which act on neurons. Astrocyte-derived ATP modulates synaptic transmission, either directly or through its metabolic product adenosine. D-serine modulates NMDA receptor function, whereas glia-derived glutamate can play important roles in relapse following withdrawal from drugs of abuse. Cell type–specific molecular genetics has allowed a new level of examination of the function of astrocytes in brain function and has revealed an important role of these glial cells that is mediated by adenosine accumulation in the control of sleep and in cognitive impairments that follow sleep deprivation. PMID:20148679

  11. 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.

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

    Directory of Open Access Journals (Sweden)

    Fontani V

    2011-11-01

    Full Text Available Vania Fontani1, Piero Mannu1,2, Alessandro Castagna1, Salvatore Rinaldi11Department of Neuro Psycho Physio Pathology, Rinaldi Fontani Institute, Florence; 2Psychic Studies Center, Cagliari, ItalyPurpose: 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

  13. 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. PMID:26095088

  14. Evaluation of drug-induced neurotoxicity based on metabolomics, proteomics and electrical activity measurements in complementary CNS in vitro models.

    Science.gov (United States)

    Schultz, Luise; Zurich, Marie-Gabrielle; Culot, Maxime; da Costa, Anaelle; Landry, Christophe; Bellwon, Patricia; Kristl, Theresa; Hörmann, Katrin; Ruzek, Silke; Aiche, Stephan; Reinert, Knut; Bielow, Chris; Gosselet, Fabien; Cecchelli, Romeo; Huber, Christian G; Schroeder, Olaf H-U; Gramowski-Voss, Alexandra; Weiss, Dieter G; Bal-Price, Anna

    2015-12-25

    The present study was performed in an attempt to develop an in vitro integrated testing strategy (ITS) to evaluate drug-induced neurotoxicity. A number of endpoints were analyzed using two complementary brain cell culture models and an in vitro blood-brain barrier (BBB) model after single and repeated exposure treatments with selected drugs that covered the major biological, pharmacological and neuro-toxicological responses. Furthermore, four drugs (diazepam, cyclosporine A, chlorpromazine and amiodarone) were tested more in depth as representatives of different classes of neurotoxicants, inducing toxicity through different pathways of toxicity. The developed in vitro BBB model allowed detection of toxic effects at the level of BBB and evaluation of drug transport through the barrier for predicting free brain concentrations of the studied drugs. The measurement of neuronal electrical activity was found to be a sensitive tool to predict the neuroactivity and neurotoxicity of drugs after acute exposure. The histotypic 3D re-aggregating brain cell cultures, containing all brain cell types, were found to be well suited for OMICs analyses after both acute and long term treatment. The obtained data suggest that an in vitro ITS based on the information obtained from BBB studies and combined with metabolomics, proteomics and neuronal electrical activity measurements performed in stable in vitro neuronal cell culture systems, has high potential to improve current in vitro drug-induced neurotoxicity evaluation.

  15. Updated summary of state electric industry restructuring activities

    International Nuclear Information System (INIS)

    For over a year, The National Regulatory Research Institute has monitored the electric industry restructuring activity at state level. Included here is a quarterly summary of a more extensive report updated and posted monthly on NRRI's website. The brief article continues by reviewing legislation and litigation in restructuring

  16. Relationship between ionospheric electric fields and magnetic activity indices

    Science.gov (United States)

    Shirapov, D. Sh.

    2012-02-01

    The relations between electric fields in the daytime and nighttime sectors of the polar ionosphere and magnetic activity indices of auroral region (AL) and northern polar cap (PCN) are studied. It is found that the above relations do exist and are described by: a) equations U {pc/(1)} (kV) = 27.62 + 21.43PCN with a correlation coefficient R = 0.87 and U {pc/(1)} (kV) = 4.06 + 49.21PCN - 6.24 PCN2 between the difference in the electric potentials across the polar cap in the daytime sector U {pc/(1)} and PCN and b) regression equation U {pc/(2)} (kV) = 23.33 + 0.08|AL| with R = 0.86 between the difference in the electric potentials across the polar cap in the nighttime sector U {pc/(2)} and |AL|. It is shown that: a) it is possible to use the AL and PCN indices for real-time diagnostics of instantaneous values of the electric fields in the daytime and nighttime sectors of the polar ionosphere in the process of a substorm development; b) at the expansion phase of a substorm, due to calibration of PCN values by the values of the solar wind electric field E sw, the PCN index does not feel the contribution of the western electrojet and, accordingly, the contribution of the nighttime ionospheric electric field U {pc/(2)}, governed by the reconnection in the magnetospheric tail.

  17. [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.

  18. Remote monitoring of biodynamic activity using electric potential sensors

    Energy Technology Data Exchange (ETDEWEB)

    Harl, C J; Prance, R J; Prance, H [Centre for Physical Electronics and Quantum Technology, Department of Engineering and Design, School of Science and Technology, University of Sussex, Brighton, BN1 9QT (United Kingdom)], E-mail: c.j.harland@sussex.ac.uk

    2008-12-01

    Previous work in applying the electric potential sensor to the monitoring of body electrophysiological signals has shown that it is now possible to monitor these signals without needing to make any electrical contact with the body. Conventional electrophysiology makes use of electrodes which are placed in direct electrical contact with the skin. The electric potential sensor requires no cutaneous electrical contact, it operates by sensing the displacement current using a capacitive coupling. When high resolution body electrophysiology is required a strong (capacitive) coupling is used to maximise the collected signal. However, in remote applications where there is typically an air-gap between the body and the sensor only a weak coupling can be achieved. In this paper we demonstrate that the electric potential sensor can be successfully used for the remote sensing and monitoring of bioelectric activity. We show examples of heart-rate measurements taken from a seated subject using sensors mounted in the chair. We also show that it is possible to monitor body movements on the opposite side of a wall to the sensor. These sensing techniques have biomedical applications for non-contact monitoring of electrophysiological conditions and can be applied to passive through-the-wall surveillance systems for security applications.

  19. Distribution of Electric Currents in Solar Active Regions

    CERN Document Server

    Török, Tibor; Titov, Viacheslav S; Archontis, Vasilis; Mikić, Zoran; Linton, Mark G; Dalmasse, Kévin; Aulanier, Guillaume; Kliem, Bernhard

    2014-01-01

    There has been a long-lasting debate on the question of whether or not electric currents in solar active regions are neutralized. That is, whether or not the main (or direct) coronal currents connecting the active region polarities are surrounded by shielding (or return) currents of equal total value and opposite direction. Both theory and observations are not yet fully conclusive regarding this question, and numerical simulations have, surprisingly, barely been used to address it. Here we quantify the evolution of electric currents during the formation of a bipolar active region by considering a three-dimensional magnetohydrodynamic simulation of the emergence of a sub-photospheric, current-neutralized magnetic flux rope into the solar atmosphere. We find that a strong deviation from current neutralization develops simultaneously with the onset of significant flux emergence into the corona, accompanied by the development of substantial magnetic shear along the active region's polarity inversion line. After t...

  20. Validating computationally predicted TMS stimulation areas using direct electrical stimulation in patients with brain tumors near precentral regions.

    Science.gov (United States)

    Opitz, Alexander; Zafar, Noman; Bockermann, Volker; Rohde, Veit; Paulus, Walter

    2014-01-01

    The spatial extent of transcranial magnetic stimulation (TMS) is of paramount interest for all studies employing this method. It is generally assumed that the induced electric field is the crucial parameter to determine which cortical regions are excited. While it is difficult to directly measure the electric field, one usually relies on computational models to estimate the electric field distribution. Direct electrical stimulation (DES) is a local brain stimulation method generally considered the gold standard to map structure-function relationships in the brain. Its application is typically limited to patients undergoing brain surgery. In this study we compare the computationally predicted stimulation area in TMS with the DES area in six patients with tumors near precentral regions. We combine a motor evoked potential (MEP) mapping experiment for both TMS and DES with realistic individual finite element method (FEM) simulations of the electric field distribution during TMS and DES. On average, stimulation areas in TMS and DES show an overlap of up to 80%, thus validating our computational physiology approach to estimate TMS excitation volumes. Our results can help in understanding the spatial spread of TMS effects and in optimizing stimulation protocols to more specifically target certain cortical regions based on computational modeling.

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

    Directory of Open Access Journals (Sweden)

    Michele T Diaz

    2014-03-01

    Full Text Available 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 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 a left posterior MTG, a region that has been linked to concept retrieval and semantic integration. Overall, the two semantic conditions (categorically-related and part-whole did not differ substantially in their functional activation which suggests a similarity in the semantic demands and lexical competition across these two conditions.

  2. Computational and experimental analysis of TMS-induced electric field vectors critical to neuronal activation

    Science.gov (United States)

    Krieg, Todd D.; Salinas, Felipe S.; Narayana, Shalini; Fox, Peter T.; Mogul, David J.

    2015-08-01

    Objective. Transcranial magnetic stimulation (TMS) represents a powerful technique to noninvasively modulate cortical neurophysiology in the brain. However, the relationship between the magnetic fields created by TMS coils and neuronal activation in the cortex is still not well-understood, making predictable cortical activation by TMS difficult to achieve. Our goal in this study was to investigate the relationship between induced electric fields and cortical activation measured by blood flow response. Particularly, we sought to discover the E-field characteristics that lead to cortical activation. Approach. Subject-specific finite element models (FEMs) of the head and brain were constructed for each of six subjects using magnetic resonance image scans. Positron emission tomography (PET) measured each subject’s cortical response to image-guided robotically-positioned TMS to the primary motor cortex. FEM models that employed the given coil position, orientation, and stimulus intensity in experimental applications of TMS were used to calculate the electric field (E-field) vectors within a region of interest for each subject. TMS-induced E-fields were analyzed to better understand what vector components led to regional cerebral blood flow (CBF) responses recorded by PET. Main results. This study found that decomposing the E-field into orthogonal vector components based on the cortical surface geometry (and hence, cortical neuron directions) led to significant differences between the regions of cortex that were active and nonactive. Specifically, active regions had significantly higher E-field components in the normal inward direction (i.e., parallel to pyramidal neurons in the dendrite-to-axon orientation) and in the tangential direction (i.e., parallel to interneurons) at high gradient. In contrast, nonactive regions had higher E-field vectors in the outward normal direction suggesting inhibitory responses. Significance. These results provide critical new

  3. Effect of transcutaneous electric stimulation on the cardiac electrical activity in New Zealand white rabbits

    Directory of Open Access Journals (Sweden)

    Wang ZHANG

    2015-10-01

    Full Text Available Objective To study the effect of transcutaneous electric stimulation on the cardiac electrical activity in New Zealand white rabbits, in order to search a safety threshold for clinical electrical stimulation therapy, as to provide the theoretical basis for the design of in vitro pacemaker. Methods New Zealand white rabbits were randomly assigned into 17 groups (6 each. Rabbits in 16 experimental groups were given 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75 and 80V electrical stimulation, respectively, with the stimulating site designated at epigastric region. BL -420F biological function experimental system was employed to supply the power and acquire the ECG, with the output pulse electrical stimulation frequency set at 270 times/minute, and the stimulating wave as square wave. A control group was set, in which the stimulating voltage was set to 35V, the stimulant anode was located in the anterior chest area, and the cathode was on the skin surface of back corresponding to the site of the heart, and the rest was the same as in experimental groups. Results No stimulation rhythm was observed in rabbits of those experimental groups with voltage ≤35V, but all stimulation rhythm was observed in rabbits of control group. No arrhythmia occurred in rabbits of those experimental groups with voltage ≤30V, while the heart rate was slowed down after stimulation in rabbits of the experimental groups with voltage ≥45V stimulation. In rabbits receiving stimulation with voltage ≤35V there was no dystropy or light dystropy, but with no visible injury to the local tissues. No visible injury was observed in the rabbits undergoing stimulation with voltage ≤40V. Conclusion Pulse electric stimulation with voltage ≤35V in the epigastric region would not affect the cardiac electrical activity in rabbits, while stimulation with 35V will lead to all pacing rhythm of the heart without affecting the cardiac electrical activity in rabbits

  4. 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.

  5. Some Problems for Representations of Brain Organization Based on Activation in Functional Imaging

    Science.gov (United States)

    Sidtis, John J.

    2007-01-01

    Functional brain imaging has overshadowed traditional lesion studies in becoming the dominant approach to the study of brain-behavior relationships. The proponents of functional imaging studies frequently argue that this approach provides an advantage over lesion studies by observing normal brain activity in vivo without the disruptive effects of…

  6. Using Proton Magnetic Resonance Imaging and Spectroscopy to Understand Brain "Activation"

    Science.gov (United States)

    Baslow, Morris H.; Guilfoyle, David N.

    2007-01-01

    Upon stimulation, areas of the brain associated with specific cognitive processing tasks may undergo observable physiological changes, and measures of such changes have been used to create brain maps for visualization of stimulated areas in task-related brain "activation" studies. These perturbations usually continue throughout the period of the…

  7. Can Electrical Vestibular Noise Be Used for the Treatment of Brain Diseases?

    Science.gov (United States)

    Yamamoto, Yoshiharu; Soma, Rika; Struzik, Zbigniew R.; Kwak, Shin

    2005-11-01

    The therapy currently available for the treatment of degenerative neurological diseases is far from satisfactory, and a novel therapeutic strategy, especially for pharmacologically unresponsive patients, would be welcomed. The vestibular nerves are known to influence neuronal circuits in the medullary cardiovascular areas and, through the cerebellar vermis, the basal ganglia and the limbic system. By means of noisy galvanic vestibular stimulation (GVS), it may now be possible to ameliorate blunted responsiveness of degenerated neuronal circuits in the brains of multiple system atrophy (MSA) and/or Parkinson's disease (PD) patients, through a mechanism known as stochastic resonance. We evaluate the effect of 24-hour noisy GVS on long-term heart rate dynamics in seven MSA patients, and on daytime locomotor activity dynamics in twelve patients with either PD or levodopa unresponsive parkinsonism. Short-range heart rate variability and long-range anti-correlation of trunk activity are significantly increased by the noisy GVS compared with sham stimulation, suggestive of improved autonomic and motor responsiveness. The noisy GVS is effective in boosting the neuro-degenerative brains of MSA and/or PD patients, including those unresponsive to standard levodopa therapy.

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

    Science.gov (United States)

    Hirata, Akimasa; Takano, Yukinori; Fujiwara, Osamu; Dovan, Thanh; Kavet, Robert

    2011-07-01

    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(-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(-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

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

    OpenAIRE

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

    2013-01-01

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

  10. Acute moderate exercise enhances compensatory brain activation in older adults.

    Science.gov (United States)

    Hyodo, Kazuki; Dan, Ippeita; Suwabe, Kazuya; Kyutoku, Yasushi; Yamada, Yuhki; Akahori, Mitsuya; Byun, Kyeongho; Kato, Morimasa; Soya, Hideaki

    2012-11-01

    A growing number of reports state that regular exercise enhances brain function in older adults. Recently a functional near-infrared spectroscopy (fNIRS) study revealed that an acute bout of moderate exercise enhanced activation of the left dorsolateral prefrontal cortex (L-DLPFC) associated with Stroop interference in young adults. Whether this acute effect is also applicable to older adults was examined. Sixteen older adults performed a color-word matching Stroop task before and after 10 minutes of exercise on a cycle ergometer at a moderate intensity. Cortical hemodynamics of the prefrontal area was monitored with a fNIRS during the Stroop task. We analyzed Stroop interference (incongruent-neutral) as Stroop performance. Though activation for Stroop interference was found in the bilateral prefrontal area before the acute bout of exercise, activation of the right frontopolar area (R-FPA) was enhanced after exercise. In the majority of participants, this coincided with improved performance reflected in Stroop interference results. Thus, an acute bout of moderate exercise improved Stroop performance in older adults, and this was associated with contralateral compensatory activation. PMID:22300952

  11. Perceived causality influences brain activity evoked by biological motion.

    Science.gov (United States)

    Morris, James P; Pelphrey, Kevin A; McCarthy, Gregory

    2008-01-01

    Using functional magnetic resonance imaging (fMRI), we investigated brain activity in an observer who watched the hand and arm motions of an individual when that individual was, or was not, the cause of the motion. Subjects viewed a realistic animated 3D character who sat at a table containing four pistons. On Intended Motion trials, the character raised his hand and arm upwards. On Unintended Motion trials, the piston under one of the character's hands pushed the hand and arm upward with the same motion. Finally, during Non-Biological Motion control trials, a piston pushed a coffee mug upward in the same smooth motion. Hand and arm motions, regardless of intention, evoked significantly more activity than control trials in a bilateral region that extended ventrally from the posterior superior temporal sulcus (pSTS) region and which was more spatially extensive in the right hemisphere. The left pSTS near the temporal-parietal junction, robustly differentiated between the Intended Motion and Unintended Motion conditions. Here, strong activity was observed for Intended Motion trials, while Unintended Motion trials evoked similar activity as the coffee mug trials. Our results demonstrate a strong hemispheric bias in the role of the pSTS in the perception of causality of biological motion. PMID:18633843

  12. Brain-Computer Interface Controlled Functional Electrical Stimulation System for Ankle Movement

    Directory of Open Access Journals (Sweden)

    King Christine E

    2011-08-01

    Full Text Available Abstract Background Many neurological conditions, such as stroke, spinal cord injury, and traumatic brain injury, can cause chronic gait function impairment due to foot-drop. Current physiotherapy techniques provide only a limited degree of motor function recovery in these individuals, and therefore novel therapies are needed. Brain-computer interface (BCI is a relatively novel technology with a potential to restore, substitute, or augment lost motor behaviors in patients with neurological injuries. Here, we describe the first successful integration of a noninvasive electroencephalogram (EEG-based BCI with a noninvasive functional electrical stimulation (FES system that enables the direct brain control of foot dorsiflexion in able-bodied individuals. Methods A noninvasive EEG-based BCI system was integrated with a noninvasive FES system for foot dorsiflexion. Subjects underwent computer-cued epochs of repetitive foot dorsiflexion and idling while their EEG signals were recorded and stored for offline analysis. The analysis generated a prediction model that allowed EEG data to be analyzed and classified in real time during online BCI operation. The real-time online performance of the integrated BCI-FES system was tested in a group of five able-bodied subjects who used repetitive foot dorsiflexion to elicit BCI-FES mediated dorsiflexion of the contralateral foot. Results Five able-bodied subjects performed 10 alternations of idling and repetitive foot dorsifiexion to trigger BCI-FES mediated dorsifiexion of the contralateral foot. The epochs of BCI-FES mediated foot dorsifiexion were highly correlated with the epochs of voluntary foot dorsifiexion (correlation coefficient ranged between 0.59 and 0.77 with latencies ranging from 1.4 sec to 3.1 sec. In addition, all subjects achieved a 100% BCI-FES response (no omissions, and one subject had a single false alarm. Conclusions This study suggests that the integration of a noninvasive BCI with a lower

  13. Baseline and cognition activated brain SPECT imaging in depression

    International Nuclear Information System (INIS)

    Purpose: To evaluate the regional cerebral blood flow (rCBF) abnormalities through the semiquantitative analysis of the baseline and cognition activated rCBF imaging in unmedicated depressed patients. Methods: 27 depressed patients unmedicated by anti-depressants were enrolled. The diagnosis (depression of moderate degree with somatization) was confirmed by the ICD-10 criteria. 15 age matched normal controls were studied under identical conditions. Baseline and cognition activated 99mTc-ECD SPECT were performed on 21 of the 27 patients with depression and 13 of the 15 normal controls. Baseline 99mTc-ECD SPECT alone were performed on the rest 6 patients with depression and 2 normal controls. The cognitive activation is achieved by Wisconsin Card Sorting Test (WCST). 1110 MBq of 99mTc-ECD was administered by intravenous bolus injection 5 minutes after the onset of the WCST. Semi-quantitative analysis was conducted with the 7th, 8th, 9th, 10th, 11th slices of the transaxial imaging. rCBF ratios of every ROI were calculated using the average tissue activity in the region divided by the maximum activity in the cerebellum. Results: 1) The baseline rCBF of left frontal (0.720) and left temporal lobe (0.720) were decreased significantly in depressed patients comparing with those of the control subjects. 2) The activated rCBF of left frontal lobe (0.719) and left temporal lobe (0.690), left parietal lobe (0.701) were decreased evidently than those of the controls. Conclusions: 1) Hypoperfusions of left frontal and left temporal cortexes were identified in patients with depression. 2) The hypoperfusion of left frontal and left temporal cortexes may be the cause of cognition disorder and depressed mood in patients with depression. 3) Cognition activated brain perfusion imaging is helpful for making a more accurate diagnosis of depression

  14. Manipulating Traveling Brain Waves with Electric Fields: From Theory to Experiment.

    Science.gov (United States)

    Gluckman, Bruce J.

    2004-03-01

    Activity waves in disinhibited neocortical slices have been used as a biological model for epileptic seizure propagation [1]. Such waves have been mathematically modeled with integro-differential equations [2] representing non-local reaction diffusion dynamics of an excitable medium with an excitability threshold. Stability and propagation speed of traveling pulse solutions depend strongly on the threshold in the following manner: propagation speed should decrease with increased threshold over a finite range, beyond which the waves become unstable. Because populations of neurons can be polarized with an applied electric field that effectively shifts their threshold for action potential initiation [3], we predicted, and have experimentally verified, that electric fields could be used globally or locally to speed up, slow down and even block wave propagation. [1] Telfeian and Conners, Epilepsia, 40, 1499-1506, 1999. [2] Pinto and Ermentrout, SIAM J. App. Math, 62, 206-225, 2001. [3] Gluckman, et. al. J Neurophysiol. 76, 4202-5, 1996.

  15. Rapid Eye Movement and Sleep Twitches Can Enhance Brain Activity

    Directory of Open Access Journals (Sweden)

    Somia Gul

    2015-12-01

    Full Text Available Rapid eye movement sleep, or REM, is one of the five stages of sleep that most people experience nightly. It is characterized by quick, random movements of the eyes and paralysis of the muscles. We have conducted a survey based on questions related to sleeping habits and pattern of their dream. Purpose of this survey is to prove a hypothesis that says ‘rapid eye movement or sleep twitches can enhance your brain activity’. We have selected normal or healthy subjects related to different ages, gender and professions. Questionnaires were filled by these subjects and we found that mostly people experience sleep twitches and they wake up with active state of mind. We also asked their level of alertness during day time and we found that subjects are alert mostly.

  16. Hidden Stages of Cognition Revealed in Patterns of Brain Activation.

    Science.gov (United States)

    Anderson, John R; Pyke, Aryn A; Fincham, Jon M

    2016-09-01

    To advance cognitive theory, researchers must be able to parse the performance of a task into its significant mental stages. In this article, we describe a new method that uses functional MRI brain activation to identify when participants are engaged in different cognitive stages on individual trials. The method combines multivoxel pattern analysis to identify cognitive stages and hidden semi-Markov models to identify their durations. This method, applied to a problem-solving task, identified four distinct stages: encoding, planning, solving, and responding. We examined whether these stages corresponded to their ascribed functions by testing whether they are affected by appropriate factors. Planning-stage duration increased as the method for solving the problem became less obvious, whereas solving-stage duration increased as the number of calculations to produce the answer increased. Responding-stage duration increased with the difficulty of the motor actions required to produce the answer. PMID:27440808

  17. Magnetic field effects on brain monoamine oxidase activity

    Energy Technology Data Exchange (ETDEWEB)

    Borets, V.M.; Ostrovskiy, V.Yu.; Bankovskiy, A.A.; Dudinskaya, T.F.

    1985-03-01

    In view of the increasing use of magnetotherapy, studies were conducted on the effects of 35 mTesla magnetic fields on monoamine oxidase activity in the rat brain. Under in vitro conditions a constant magnetic field in the continuous mode was most effective in inhibiting deamination of dopamine following 1 min exposure, while in vivo studies with 8 min or 10 day exposures showed that inhibition was obtained only with a variable field in the continuous mode. However, inhibition of dopamine deamination was only evident within the first 24 h after exposure was terminated. In addition, in none of the cases was norepinephrine deamination inhibited. The effects of the magnetic fields were, therefore, transient and selective with the CNS as the target system. 9 references.

  18. Detection of cocaine induced rat brain activation by photoacoustic tomography

    Science.gov (United States)

    Jo, Janggun; Yang, Xinmai

    2011-01-01

    Photoacoustic tomography (PAT) was used to detect the progressive changes on the cerebral cortex of Sprague Dawley rats after the administration of cocaine hydrochloride. Different concentrations (0, 2.5, and 5.0 mg per kg body) of cocaine hydrochloride in saline solution were injected into Sprague Dawley rats through tail veins. Cerebral cortex images of the animals were continuously acquired by PAT. For continuous observation, PAT system used multi-transducers to reduce the scanning time and maintain a good signal-to-noise ratio (SNR). The obtained photoacoustic images were compared with each other and confirmed that changes in blood volume were induced by cocaine hydrochloride injection. The results demonstrate that PAT may be used to detect the effects of drug abuse-induced brain activation. PMID:21163301

  19. Brain Fingerprinting

    Directory of Open Access Journals (Sweden)

    Ravi Kumar

    2012-12-01

    Full Text Available Brain Fingerprinting is a scientific technique to determine whether or not specific information is stored in an individual's brain by measuring a electrical brain wave response to Word, phrases, or picture that are presented on computer screen. Brain Fingerprinting is a controversial forensic science technique that uses electroencephalography (EEG to determine whether specific information is stored in a subject's brain.

  20. Brain Fingerprinting

    Directory of Open Access Journals (Sweden)

    ravi kumar

    2012-12-01

    Full Text Available Brain Fingerprinting is a scientific technique to determine whether or not specific information is stored in an individual's brain by measuring a electrical brain wave response to Word, phrases, or picture that are presented on computer screen. Brain Fingerprinting is a controversial forensic science technique that uses electroencephalograph y (EEG to determine whether specific information is stored in a subject's brain

  1. Recovery of brain and plasma cholinesterase activities in ducklings exposed to organophosphorus pesticides

    Science.gov (United States)

    Fleming, W.J.

    1981-01-01

    Brain and plasma cholinesterase (ChE) activities were determined for mallard ducklings (Anas platyrhynchos) exposed to dicrotophos and fenthion. Recovery rates of brain ChE did not differ between ducklings administered a single oral dose vs. a 2-week dietary dose of these organophosphates. Exposure to the organophosphates, followed by recovery of brain ChE, did not significantly affect the degree of brain ChE inhibition or the recovery of ChE activity at a subsequent exposure. Recovery of brain ChE activity followed the general model Y = a + b(logX) with rapid recovery to about 50% of normal, followed by a slower rate of recovery until normal ChE activity levels were attained. Fenthion and dicrotophos-inhibited brain ChE were only slightly reactivated in vitro by pyridine-2-aldoxime methiodide, which suggested that spontaneous reactivation was not a primary method of recovery of ChE activity. Recovery of brain ChE activity can be modeled for interpretation of sublethal inhibition of brain ChE activities in wild birds following environmental applications of organophosphates. Plasma ChE activity is inferior to brain ChE activity for environmental monitoring, because of its rapid recovery and large degree of variation among individuals.

  2. 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

  3. Active RF Pulse Compression Using An Electrically Controlled Semiconductor Switch

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Jiquan; Tantawi, Sami; /SLAC

    2007-01-10

    First we review the theory of active pulse compression systems using resonant delay lines. Then we describe the design of an electrically controlled semiconductor active switch. The switch comprises an active window and an overmoded waveguide three-port network. The active window is based on a four-inch silicon wafer which has 960 PIN diodes. These are spatially combined in an overmoded waveguide. We describe the philosophy and design methodology for the three-port network and the active window. We then present the results of using this device to compress 11.4 GHz RF signals with high compression ratios. We show how the system can be used with amplifier like sources, in which one can change the phase of the source by manipulating the input to the source. We also show how the active switch can be used to compress a pulse from an oscillator like sources, which is not possible with passive pulse compression systems.

  4. Inhibitory effects of heterotopic noxious counter-stimulation on perception and brain activity related to Aβ-fibre activation.

    Science.gov (United States)

    Rustamov, Nabi; Tessier, Jessica; Provencher, Benjamin; Lehmann, Alexandre; Piché, Mathieu

    2016-07-01

    Heterotopic noxious counter-stimulation (HNCS) inhibits pain and pain processes through cerebral and cerebrospinal mechanisms. However, it is unclear whether HNCS inhibits non-nociceptive processes, which needs to be clarified for a better understanding of HNCS analgesia. The aim of this study was to examine the effects of HNCS on perception and scalp somatosensory evoked potentials (SEPs). Seventeen healthy volunteers participated in two counter-balanced sessions, including non-nociceptive (selective Aβ-fibre activation) or nociceptive electrical stimulation, combined with HNCS. HNCS was produced by a 20-min cold pressor test (left hand) adjusted individually to produce moderate pain (mean ± SEM: 42.5 ± 5.3 on a 0-100 scale, where 0 is no pain and 100 the worst pain imaginable). Non-nociceptive electrical stimulation was adjusted individually at 80% of pain threshold and produced a tactile sensation in every subject. Nociceptive electrical stimulation was adjusted individually at 120% of RIII-reflex threshold and produced moderate pain (45.3 ± 4.5). Shock sensation was significantly decreased by HNCS compared with baseline for non-nociceptive (P SEP peak-to-peak amplitude at Cz was significantly decreased by HNCS for non-nociceptive (P < 0.01) and nociceptive (P < 0.05) stimulation. These results indicate that perception and brain activity related to Aβ-fibre activation are inhibited by HNCS. The mechanisms of this effect remain to be investigated to clarify whether it involves inhibition of spinal wide-dynamic-range neurons by diffuse noxious inhibitory controls, supraspinal processes or both. PMID:27086672

  5. Active electric imaging: body-object interplay and object's "electric texture".

    Science.gov (United States)

    Caputi, Angel A; Aguilera, Pedro A; Pereira, Ana Carolina

    2011-01-01

    This article deals with the role of fish's body and object's geometry on determining the image spatial shape in pulse Gymnotiforms. This problem was explored by measuring local electric fields along a line on the skin in the presence and absence of objects. We depicted object's electric images at different regions of the electrosensory mosaic, paying particular attention to the perioral region where a fovea has been described. When sensory surface curvature increases relative to the object's curvature, the image details depending on object's shape are blurred and finally disappear. The remaining effect of the object on the stimulus profile depends on the strength of its global polarization. This depends on the length of the object's axis aligned with the field, in turn depending on fish body geometry. Thus, fish's body and self-generated electric field geometries are embodied in this "global effect" of the object. The presence of edges or local changes in impedance at the nearest surface of closely located objects adds peaks to the image profiles ("local effect" or "object's electric texture"). It is concluded that two cues for object recognition may be used by active electroreceptive animals: global effects (informing on object's dimension along the field lines, conductance, and position) and local effects (informing on object's surface). Since the field has fish's centered coordinates, and electrosensory fovea is used for exploration of surfaces, fish fine movements are essential to perform electric perception. We conclude that fish may explore adjacent objects combining active movements and electrogenesis to represent them using electrosensory information. PMID:21876730

  6. Active electric imaging: body-object interplay and object's "electric texture".

    Directory of Open Access Journals (Sweden)

    Angel A Caputi

    Full Text Available This article deals with the role of fish's body and object's geometry on determining the image spatial shape in pulse Gymnotiforms. This problem was explored by measuring local electric fields along a line on the skin in the presence and absence of objects. We depicted object's electric images at different regions of the electrosensory mosaic, paying particular attention to the perioral region where a fovea has been described. When sensory surface curvature increases relative to the object's curvature, the image details depending on object's shape are blurred and finally disappear. The remaining effect of the object on the stimulus profile depends on the strength of its global polarization. This depends on the length of the object's axis aligned with the field, in turn depending on fish body geometry. Thus, fish's body and self-generated electric field geometries are embodied in this "global effect" of the object. The presence of edges or local changes in impedance at the nearest surface of closely located objects adds peaks to the image profiles ("local effect" or "object's electric texture". It is concluded that two cues for object recognition may be used by active electroreceptive animals: global effects (informing on object's dimension along the field lines, conductance, and position and local effects (informing on object's surface. Since the field has fish's centered coordinates, and electrosensory fovea is used for exploration of surfaces, fish fine movements are essential to perform electric perception. We conclude that fish may explore adjacent objects combining active movements and electrogenesis to represent them using electrosensory information.

  7. 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

    2015-12-01

    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 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.

  8. 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

  9. Activity based models for countrywide electric vehicle power demand calculation

    OpenAIRE

    Knapen, Luk; Kochan, Bruno; BELLEMANS, Tom; JANSSENS, Davy; Wets, Geert

    2011-01-01

    Smart grid design depends on the availability of realistic data. In the near future, energy demand by electric vehicles will be a substantial component of the overall demand and peaks of required power could become critical in some regions. Transportation research has been using micro-simulation based activity-based models for traffic forecasting. The resulting trip length distribution allows to estimate to what extent internal combustion engine vehicles can be substituted...

  10. Extracellular electrical activity from the photoreceptors of midge

    Indian Academy of Sciences (India)

    A A Babrekar; G R Kulkarni; B B Nath; P B Vidyasagar

    2004-09-01

    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 photosensitivity as the larva metamorphosed to the adult stage. This is the first report of changes in photosensitivity during the development of any insect described in an ecological context.

  11. Analyzing the tradeoff between electrical complexity and accuracy in patient-specific computational models of deep brain stimulation

    Science.gov (United States)

    Howell, Bryan; McIntyre, Cameron C.

    2016-06-01

    Objective. Deep brain stimulation (DBS) is an adjunctive therapy that is effective in treating movement disorders and shows promise for treating psychiatric disorders. Computational models of DBS have begun to be utilized as tools to optimize the therapy. Despite advancements in the anatomical accuracy of these models, there is still uncertainty as to what level of electrical complexity is adequate for modeling the electric field in the brain and the subsequent neural response to the stimulation. Approach. We used magnetic resonance images to create an image-based computational model of subthalamic DBS. The complexity of the volume conductor model was increased by incrementally including heterogeneity, anisotropy, and dielectric dispersion in the electrical properties of the brain. We quantified changes in the load of the electrode, the electric potential distribution, and stimulation thresholds of descending corticofugal (DCF) axon models. Main results. Incorporation of heterogeneity altered the electric potentials and subsequent stimulation thresholds, but to a lesser degree than incorporation of anisotropy. Additionally, the results were sensitive to the choice of method for defining anisotropy, with stimulation thresholds of DCF axons changing by as much as 190%. Typical approaches for defining anisotropy underestimate the expected load of the stimulation electrode, which led to underestimation of the extent of stimulation. More accurate predictions of the electrode load were achieved with alternative approaches for defining anisotropy. The effects of dielectric dispersion were small compared to the effects of heterogeneity and anisotropy. Significance. The results of this study help delineate the level of detail that is required to accurately model electric fields generated by DBS electrodes.

  12. Optical imaging of neural and hemodynamic brain activity

    Science.gov (United States)

    Schei, Jennifer Lynn

    Optical imaging technologies can be used to record neural and hemodynamic activity. Neural activity elicits physiological changes that alter the optical tissue properties. Specifically, changes in polarized light are concomitant with neural depolarization. We measured polarization changes from an isolated lobster nerve during action potential propagation using both reflected and transmitted light. In transmission mode, polarization changes were largest throughout the center of the nerve, suggesting that most of the optical signal arose from the inner nerve bundle. In reflection mode, polarization changes were largest near the edges, suggesting that most of the optical signal arose from the outer sheath. To overcome irregular cell orientation found in the brain, we measured polarization changes from a nerve tied in a knot. Our results show that neural activation produces polarization changes that can be imaged even without regular cell orientations. Neural activation expends energy resources and elicits metabolic delivery through blood vessel dilation, increasing blood flow and volume. We used spectroscopic imaging techniques combined with electrophysiological measurements to record evoked neural and hemodynamic responses from the auditory cortex of the rat. By using implantable optics, we measured responses across natural wake and sleep states, as well as responses following different amounts of sleep deprivation. During quiet sleep, evoked metabolic responses were larger compared to wake, perhaps because blood vessels were more compliant. When animals were sleep deprived, evoked hemodynamic responses were smaller following longer periods of deprivation. These results suggest that prolonged neural activity through sleep deprivation may diminish vascular compliance as indicated by the blunted vascular response. Subsequent sleep may allow vessels to relax, restoring their ability to deliver blood. These results also suggest that severe sleep deprivation or chronic

  13. Functional electrical stimulation-facilitated proliferation and regeneration of neural precursor cells in the brains of rats with cerebral infarction

    Institute of Scientific and Technical Information of China (English)

    Yun Xiang; Huihua Liu; Tiebin Yan; Zhiqiang Zhuang; Dongmei Jin; Yuan Peng

    2014-01-01

    Previous studies have shown that proliferation of endogenous neural precursor cells cannot alone compensate for the damage to neurons and axons. From the perspective of neural plastici-ty, we observed the effects of functional electrical stimulation treatment on endogenous neural precursor cell proliferation and expression of basic fibroblast growth factor and epidermal growth factor in the rat brain on the infarct side. Functional electrical stimulation was performed in rat models of acute middle cerebral artery occlusion. Simultaneously, we set up a placebo stimulation group and a sham-operated group. Immunohistochemical staining showed that, at 7 and 14 days, compared with the placebo group, the numbers of nestin (a neural precursor cell marker)-positive cells in the subgranular zone and subventricular zone were increased in the functional electrical stimulation treatment group. Western blot assays and reverse-transcription PCR showed that total protein levels and gene expression of epidermal growth factor and basic ifbroblast growth factor were also upregulated on the infarct side. Prehensile traction test results showed that, at 14 days, prehension function of rats in the functional electrical stimulation group was signiifcantly better than in the placebo group. These results suggest that functional electrical stimulation can promote endogenous neural precursor cell proliferation in the brains of acute cerebral infarction rats, enhance expression of basic fibroblast growth factor and epidermal growth factor, and improve the motor function of rats.

  14. 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.

  15. Multistability in Large Scale Models of Brain Activity.

    Directory of Open Access Journals (Sweden)

    Mathieu Golos

    2015-12-01

    Full Text Available Noise driven exploration of a brain network's dynamic repertoire has been hypothesized to be causally involved in cognitive function, aging and neurodegeneration. The dynamic repertoire crucially depends on the network's capacity to store patterns, as well as their stability. Here we systematically explore the capacity of networks derived from human connectomes to store attractor states, as well as various network mechanisms to control the brain's dynamic repertoire. Using a deterministic graded response Hopfield model with connectome-based interactions, we reconstruct the system's attractor space through a uniform sampling of the initial conditions. Large fixed-point attractor sets are obtained in the low temperature condition, with a bigger number of attractors than ever reported so far. Different variants of the initial model, including (i a uniform activation threshold or (ii a global negative feedback, produce a similarly robust multistability in a limited parameter range. A numerical analysis of the distribution of the attractors identifies spatially-segregated components, with a centro-medial core and several well-delineated regional patches. Those different modes share similarity with the fMRI independent components observed in the "resting state" condition. We demonstrate non-stationary behavior in noise-driven generalizations of the models, with different meta-stable attractors visited along the same time course. Only the model with a global dynamic density control is found to display robust and long-lasting non-stationarity with no tendency toward either overactivity or extinction. The best fit with empirical signals is observed at the edge of multistability, a parameter region that also corresponds to the highest entropy of the attractors.

  16. 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

  17. 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

  18. Discrete, 3D distributed, linear imaging methods of electric neuronal activity. Part 1: exact, zero error localization

    CERN Document Server

    Pascual-Marqui, Roberto D

    2007-01-01

    This paper deals with the EEG/MEG neuroimaging problem: given measurements of scalp electric potential differences (EEG: electroencephalogram) and extracranial magnetic fields (MEG: magnetoencephalogram), find the 3D distribution of the generating electric neuronal activity. This problem has no unique solution. Only particular solutions with "good" localization properties are of interest, since neuroimaging is concerned with the localization of brain function. In this paper, a general family of linear imaging methods with exact, zero error localization to point-test sources is presented. One particular member of this family is sLORETA (standardized low resolution brain electromagnetic tomography; Pascual-Marqui, Methods Find. Exp. Clin. Pharmacol. 2002, 24D:5-12; http://www.unizh.ch/keyinst/NewLORETA/sLORETA/sLORETA-Math01.pdf). It is shown here that sLORETA has no localization bias in the presence of measurement and biological noise. Another member of this family, denoted as eLORETA (exact low resolution bra...

  19. Brain oscillatory activity during motor imagery in EEG-fMRI coregistration.

    Science.gov (United States)

    Formaggio, Emanuela; Storti, Silvia Francesca; Cerini, Roberto; Fiaschi, Antonio; Manganotti, Paolo

    2010-12-01

    The purpose of the present work was to investigate the correlation between topographical changes in brain oscillatory activity and the blood oxygenation level-dependent (BOLD) signal during a motor imagery (MI) task using electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) coregistration. EEG was recorded in 7 healthy subjects inside a 1.5 T MR scanner during the imagination of the kinesthetic experience of movement. A Fast Fourier Transform was applied to EEG signal in the rest and active conditions. We used the event-related-synchronization (ERS)/desynchronization (ERD) approach to characterize where the imagination of movement produces a decrease in alpha and beta power. The mean alpha map showed ERD decrease localized over the contralateral sensory motor area (SM1c) and a light desynchronization in the ipsilateral sensory motor area (SM1i); whereas the mean beta map showed ERD decrease over the supplementary motor area (SMA). fMRI showed significant activation in SMA, SM1c, SM1i. The correlation is negative in the contralateral side and positive in the ipsilateral side. Using combined EEG-fMRI signals we obtained useful new information on the description of the changes in oscillatory activity in alpha and beta bands during MI and on the investigation of the sites of BOLD activity as possible sources in generating these rhythms. By correlating BOLD and ERD/ERS we may identify more accurately which regions contribute to changes of the electrical response. PMID:20850237

  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. Time-invariant person-specific frequency templates in human brain activity

    OpenAIRE

    Doron, Itai; Hulata, Eyal; Baruchi, Itay; Towle, Vernon L.; Ben-Jacob, Eshel

    2006-01-01

    The various human brain tasks are performed at different locations and time scales. Yet, we discovered the existence of time-invariant (above an essential time scale) partitioning of the brain activity into personal state-specific frequency bands. For that, we perform temporal and ensemble averaging of best wavelet packet bases from multi-electrode EEG recordings. These personal frequency-bands provide new templates for quantitative analyses of brain function, e.g., normal vs. epileptic activ...

  2. Blood-Brain Barrier Active Efflux Transporters: ATP-Binding Cassette Gene Family

    OpenAIRE

    Löscher, Wolfgang; Potschka, Heidrun

    2005-01-01

    Summary: The blood-brain barrier (BBB) contributes to brain homeostasis by protecting the brain from potentially harmful endogenous and exogenous substances. BBB active drug efflux transporters of the ATP-binding cassette (ABC) gene family are increasingly recognized as important determinants of drug distribution to, and elimination from, the CNS. The ABC efflux transporter P-glycoprotein (Pgp) has been demonstrated as a key element of the BBB that can actively transport a huge variety of lip...

  3. Objectively Measured Physical Activity Is Associated with Brain Volumetric Measurements in Multiple Sclerosis

    OpenAIRE

    Klaren, Rachel E; Hubbard, Elizabeth A.; Motl, Robert W.; Pilutti, Lara A.; Wetter, Nathan C.; Sutton, Bradley P.

    2015-01-01

    Background. Little is known about physical activity and its association with volumes of whole brain gray matter and white matter and deep gray matter structures in persons with multiple sclerosis (MS). Purpose. This study examined the association between levels of physical activity and brain volumetric measures from magnetic resonance imaging (MRI) in MS. Method. 39 persons with MS wore an accelerometer for a 7-day period and underwent a brain MRI. Normalized GM volume (NGMV), normalized WM v...

  4. Brain activity during driving with distraction: an immersive fMRI study

    OpenAIRE

    Tom A Schweizer; Karen Kan; Yuwen Hung; Fred Tam; Gary Naglie; Simon Graham

    2013-01-01

    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. Materials and Methods: To capture brain activity during driving, we placed a driving simulator with a fully functio...

  5. The Energy Landscape of Neurophysiological Activity Implicit in Brain Network Structure

    OpenAIRE

    Gu, Shi; Cieslak, Matthew; Baird, Benjamin; Muldoon, Sarah F.; Grafton, Scott T; Pasqualetti, Fabio; Danielle S Bassett

    2016-01-01

    A critical mystery in neuroscience lies in determining how anatomical structure impacts the complex functional dynamics of human thought. How does large-scale brain circuitry constrain states of neuronal activity and transitions between those states? We address these questions using a maximum entropy model of brain dynamics informed by white matter tractography. We demonstrate that the most probable brain states -- characterized by minimal energy -- display common activation profiles across b...

  6. 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.

  7. 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.

  8. A Three Spatial Dimension Wave Latent Force Model for Describing Excitation Sources and Electric Potentials Produced by Deep Brain Stimulation

    OpenAIRE

    Alvarado, Pablo A.; Álvarez, Mauricio A.; Orozco, Álvaro A.

    2016-01-01

    Deep brain stimulation (DBS) is a surgical treatment for Parkinson's Disease. Static models based on quasi-static approximation are common approaches for DBS modeling. While this simplification has been validated for bioelectric sources, its application to rapid stimulation pulses, which contain more high-frequency power, may not be appropriate, as DBS therapeutic results depend on stimulus parameters such as frequency and pulse width, which are related to time variations of the electric fiel...

  9. Visual image reconstruction from human brain activity: A modular decoding approach

    International Nuclear Information System (INIS)

    Brain activity represents our perceptual experience. But the potential for reading out perceptual contents from human brain activity has not been fully explored. In this study, we demonstrate constraint-free reconstruction of visual images perceived by a subject, from the brain activity pattern. We reconstructed visual images by combining local image bases with multiple scales, whose contrasts were independently decoded from fMRI activity by automatically selecting relevant voxels and exploiting their correlated patterns. Binary-contrast, 10 x 10-patch images (2100 possible states), were accurately reconstructed without any image prior by measuring brain activity only for several hundred random images. The results suggest that our approach provides an effective means to read out complex perceptual states from brain activity while discovering information representation in multi-voxel patterns.

  10. 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.

  11. Localization of brain activities using multiway analysis of EEG tensor via EMD and reassigned TF representation.

    Science.gov (United States)

    Pouryazdian, Saeed; Beheshti, Soosan; Krishnan, Sridhar

    2015-01-01

    Electroencephalogram (EEG) is widely used for monitoring, diagnosis purposes and also for study of brain's physiological, mental and functional abnormalities. Processing of information by the brain is reflected in dynamical changes of the electrical activity in time, frequency, and space. EEG signal processing tends to describe and quantify these variations in such a way that they are localized in temporal, spectral and spatial domain. Here we use multi-way (Tensor) analysis for localizing the EEG events. We used EMD process for decomposing EEG into distinct oscillatory modes, which are then mapped to TF plane using the near optimal Reassigned Spectrogram. Temporal, Spatial and Spectral information of the Multichannel EEG are then used to generate a three-way Frequency-Time-Space EEG tensor. Exploiting EMD also enables us to detrend the EEG recordings. Simulation results on both synthetic and real EEG data show that tensor analysis greatly improve separation and localization of overlapping events in EEG and it could be effectively exploited for detecting and characterizing the evoked potentials.

  12. Electrical impedance tomography system based on active electrodes

    International Nuclear Information System (INIS)

    Electrical impedance tomography (EIT) can image the distribution of ventilated lung tissue, and is thus a promising technology to help monitor patient breathing to help selection of mechanical ventilation parameters. Two key difficulties in EIT instrumentation make such monitoring difficult: (1) EIT data quality depends on good electrode contact and is sensitive to changes in contact quality, and (2) EIT electrodes are difficult and time consuming to place on patients. This paper presents the design and initial tests of an active electrode-based system to address these difficulties. Our active electrode EIT system incorporates an active electrode belt, a central voltage-driven current source, central analog to digital converters and digital to analog converters, a central FPGA-based demodulator and controller. The electrode belt is designed incorporating 32 active electrodes, each of which contains the electronic amplifiers, switches and associated logic. Tests show stable device performance with a convenient ease of use and good imaging ability in volunteer tests. (paper)

  13. 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.

  14. Targeting complement activation in brain-dead donors improves renal function after transplantation

    NARCIS (Netherlands)

    Damman, Jeffrey; Hoeger, Simone; Boneschansker, Leo; Theruvath, Ashok; Waldherr, Ruediger; Leuvenink, Henri G.; Ploeg, Rutger J.; Yard, Benito A.; Seelen, Marc A.

    2011-01-01

    Kidneys recovered from brain-dead donors have inferior outcomes after transplantation compared to kidneys from living donors. Since complement activation plays an important role in renal transplant related injury, targeting complement activation in brain-dead donors might improve renal function afte

  15. 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…

  16. Sex Differences in Brain Activity Related to General and Emotional Intelligence

    Science.gov (United States)

    Jausovec, Norbert; Jausovec, Ksenija

    2005-01-01

    The study investigated gender differences in resting EEG (in three individually determined narrow [alpha] frequency bands) related to the level of general and emotional intelligence. Brain activity of males decreased with the level of general intelligence, whereas an opposite pattern of brain activity was observed in females. This difference was…

  17. 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.

  18. 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

    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.

  19. 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

    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...

  20. Task-Driven Activity Reduces the Cortical Activity Space of the Brain: Experiment and Whole-Brain Modeling.

    OpenAIRE

    Adrián Ponce-Alvarez; He, Biyu J.; Patric Hagmann; Gustavo Deco

    2015-01-01

    How a stimulus or a task alters the spontaneous dynamics of the brain remains a fundamental open question in neuroscience. One of the most robust hallmarks of task/stimulus-driven brain dynamics is the decrease of variability with respect to the spontaneous level, an effect seen across multiple experimental conditions and in brain signals observed at different spatiotemporal scales. Recently, it was observed that the trial-to-trial variability and temporal variance of functional magnetic reso...

  1. Control of programmed cell death by distinct electrical activity patterns.

    Science.gov (United States)

    Golbs, Antje; Nimmervoll, Birgit; Sun, Jyh-Jang; Sava, Irina E; Luhmann, Heiko J

    2011-05-01

    Electrical activity and sufficient supply with survival factors play a major role in the control of apoptosis in the developing cortex. Coherent high-frequency neuronal activity, which efficiently releases neurotrophins, is essential for the survival of immature neurons. We studied the influence of neuronal activity on apoptosis in the developing cortex. Dissociated cultures of the newborn mouse cerebral cortex were grown on multielectrode arrays to determine the activity patterns that promote neuronal survival. Cultures were transfected with a plasmid coding for a caspase-3-sensitive fluorescent protein allowing real-time analysis of caspase-3-dependent apoptosis in individual neurons. Elevated extracellular potassium concentrations (5 and 8 mM), application of 4-aminopyridine or the γ-aminobutyric acid-A receptor antagonist Gabazine induced a shift in the frequency distribution of activity toward high-frequency bursts. Under these conditions, a reduction or delay in caspase-3 activation and an overall increase in neuronal survival could be observed. This effect was dependent on the activity of phosphatidylinositol-3 kinase, as blockade of this enzyme abolished the survival-promoting effect of high extracellular potassium concentrations. Our data indicate that increased network activity can prevent apoptosis in developing cortical neurons.

  2. Transcranial Electric Field Stimulation

    OpenAIRE

    Arfaee, Arash

    2015-01-01

    Nervous stimulation with electric methods not only has a long history in the treatment of many conditions but also in the last two decades has been used increasingly as a powerful functional brain mapping tool alongside other imaging techniques. This technology has been used to record the stimulation-evoked activity of the stimulated location. This research describes work surrounding a novel technique for brain and nervous stimulation using the electric field as the medium; particularly tra...

  3. The Development of control system via Brain Computer Interface (BCI - Functional Electrical Stimulation (FES for paraplegic subject

    Directory of Open Access Journals (Sweden)

    K. A. A. Rahman

    2012-12-01

    Full Text Available Brain is known to be one of the powerful systems in human body because of its ability to give command and communicate throughout the body. The spinal cord is the pathway for impulses from the brain to the body as well as from the body to the brain. However, the bounty of this pathway could be lost due to spinal cord injury (SCI and that results in a loss of function especially mobility. A combination of Brain Computer Interface (BCI and Functional Electrical Stimulation (FES is among one of the technique to regain the mobility function of human body which will be the focused area of this research. In this study, Electroencephalography (EEG system will be used to capture the brain signal which will then drive the FES. A paraplegic subject will be involved in this study. The subject will be required to move the knee joint with involvement few muscle contraction. Overall, in this paper the combination of BCI-FES methods for development of rehabilitation system will be proposed. From this preliminary study, it can be summarized that the combination between BCI and FES potentially would provide a better rehabilitation system for SCI patient in comparison to the conventional FES system.

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

    OpenAIRE

    Tzyy-Nan eHuang; Yi-Ping eHsueh

    2015-01-01

    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 g...

  5. Is Brain Activity during Action Observation Modulated by the Perceived Fairness of the Actor?

    OpenAIRE

    Etzel, Joset A.; Nikola Valchev; Valeria Gazzola; Christian Keysers

    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 when experiencing similar emotions directly. This emotion perception associated activity has been shown to be affected by the perceived fairness of the actor, and in-group membership more generally...

  6. Electrical stimulation alleviates depressive-like behaviors of rats: investigation of brain targets and potential mechanisms

    OpenAIRE

    Lim, L.W.; Prickaerts, J.; Huguet, G; Kadar, E; Hartung, H; Sharp, T; Y. Temel

    2015-01-01

    Deep brain stimulation (DBS) is a promising therapy for patients with refractory depression. However, key questions remain with regard to which brain target(s) should be used for stimulation, and which mechanisms underlie the therapeutic effects. Here, we investigated the effect of DBS, with low- and high-frequency stimulation (LFS, HFS), in different brain regions (ventromedial prefrontal cortex, vmPFC; cingulate cortex, Cg; nucleus accumbens (NAc) core or shell; lateral habenula, LHb; and v...

  7. 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.

  8. 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.

  9. Research progress in nonlinear analysis of heart electric activities

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Nonlinear science research is a hot point in the world. It has deepened our cognition of determinism and randomicity, simplicity and complexity, noise and order and it will profoundly influence the progress of the study of natural science, including life science.Life is the most complex nonlinear system and heart is the core of lifecycle system. In the late more than 20 years, nonlinear research on heart electric activities has made much headway. The commonly used parameters are based on chaos and fractal theory, such as correlation dimension, Lyapunov exponent, Kolmogorov entropy and multifractal singularity spectrum. This paper summarizes the commonly used methods in the nonlinear study of heart electric signal. Then, considering the shortages of the above traditional nonlinear parameters, we mainly introduce the results on short-term heart rate variability (HRV) signal (500 R-R intervals) and HFECG signal (1-2s). Finally, we point out it is worthwhile to put emphasis on the study of the sensitive nonlinearity parameters of short-term heart electric signal and their dynamic character and clinical effectivity.

  10. Cocaine is pharmacologically active in the nonhuman primate fetal brain

    OpenAIRE

    Benveniste, Helene; Fowler, Joanna S.; Rooney, William D; Scharf, Bruce A.; Backus, W. Walter; Izrailtyan, Igor; Knudsen, Gitte M; Hasselbalch, Steen G; Volkow, Nora D.

    2010-01-01

    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-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 (∼100%). Inasmuch as brain...

  11. Task-free MRI predicts individual differences in brain activity during task performance.

    Science.gov (United States)

    Tavor, I; Parker Jones, O; Mars, R B; Smith, S M; Behrens, T E; Jbabdi, S

    2016-04-01

    When asked to perform the same task, different individuals exhibit markedly different patterns of brain activity. This variability is often attributed to volatile factors, such as task strategy or compliance. We propose that individual differences in brain responses are, to a large degree, inherent to the brain and can be predicted from task-independent measurements collected at rest. Using a large set of task conditions, spanning several behavioral domains, we train a simple model that relates task-independent measurements to task activity and evaluate the model by predicting task activation maps for unseen subjects using magnetic resonance imaging. Our model can accurately predict individual differences in brain activity and highlights a coupling between brain connectivity and function that can be captured at the level of individual subjects.

  12. Whole-Brain Mapping of Neuronal Activity in the Learned Helplessness Model of Depression.

    Science.gov (United States)

    Kim, Yongsoo; Perova, Zinaida; Mirrione, Martine M; Pradhan, Kith; Henn, Fritz A; Shea, Stephen; Osten, Pavel; Li, Bo

    2016-01-01

    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. PMID:26869888

  13. 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.

  14. Physical activity, body mass index, and brain atrophy in Alzheimer's disease.

    Science.gov (United States)

    Boyle, Christina P; Raji, Cyrus A; Erickson, Kirk I; Lopez, Oscar L; Becker, James T; Gach, H Michael; Longstreth, W T; Teverovskiy, Leonid; Kuller, Lewis H; Carmichael, Owen T; Thompson, Paul M

    2015-01-01

    The purpose of this study was to use a novel imaging biomarker to assess associations between physical activity (PA), body mass index (BMI), and brain structure in normal aging, mild cognitive impairment, and Alzheimer's dementia. We studied 963 participants (mean age: 74.1 ± 4.4 years) from the multisite Cardiovascular Health Study including healthy controls (n = 724), Alzheimer's dementia patients (n = 104), and people with mild cognitive impairment (n = 135). Volumetric brain images were processed using tensor-based morphometry to analyze regional brain volumes. We regressed the local brain tissue volume on reported PA and computed BMI, and performed conjunction analyses using both variables. Covariates included age, sex, and study site. PA was independently associated with greater whole brain and regional brain volumes and reduced ventricular dilation. People with higher BMI had lower whole brain and regional brain volumes. A PA-BMI conjunction analysis showed brain preservation with PA and volume loss with increased BMI in overlapping brain regions. In one of the largest voxel-based cross-sectional studies to date, PA and lower BMI may be beneficial to the brain across the spectrum of aging and neurodegeneration.

  15. Individual human brain areas can be identified from their characteristic spectral activation fingerprints

    OpenAIRE

    Keitel, Anne; Gross, Joachim

    2016-01-01

    The human brain can be parcellated into diverse anatomical areas. We investigated whether rhythmic brain activity in these areas is characteristic and can be used for automatic classification. To this end, resting-state MEG data of 22 healthy adults was analysed. Power spectra of 1-s long data segments for atlas-defined brain areas were clustered into spectral profiles (“fingerprints”), using k-means and Gaussian mixture (GM) modelling. We demonstrate that individual areas can be identified f...

  16. The effect of Quinpirol and Sulpiride on the brain activity waves in conscious and aneasthetized rat

    OpenAIRE

    Komaki AR; Alaie H

    1998-01-01

    Brain's waves are produced by spontaneous activity of neurons. These waves are changed by neurotransmitters in the central nervous system (CNS). Concentration of these neurotransmitters can be changed by various drugs and total power of brain waves also increase or decrease by these drugs. In this research effect of Quinpirol and Sulpiride on the brain waves was investigated. Male wistar rats (weight 190-230) were aneasthetized with thiopental and two holes were made into the frontal and...

  17. Electrical activity patterns and the functional maturation of the neocortex.

    Science.gov (United States)

    Kilb, Werner; Kirischuk, Sergei; Luhmann, Heiko J

    2011-11-01

    At the earliest developmental stages, sensory neocortical areas in various species reveal distinct patterns of spontaneous neuronal network activity. These activity patterns either propagate over large neocortical areas or synchronize local neuronal ensembles. In vitro and in vivo experiments indicate that these spontaneous activity patterns are generated from neuronal networks in the cerebral cortex, in subcortical structures or in the sensory periphery (retina, cochlea, whiskers). At early stages spontaneous periphery-driven and also sensory evoked activity is relayed to the developing cerebral cortex via the thalamus and the neocortical subplate, which amplifies the afferent sensory input. These early local and large-scale neuronal activity patterns influence a variety of developmental processes during corticogenesis, such as neurogenesis, apoptosis, neuronal migration, differentiation and network formation. The experimental data also indicate that disturbances in early neuronal patterns may have an impact on the development of cortical layers, columns and networks. In this article we review our current knowledge on the origin of early electrical activity patterns in neocortical sensory areas and their functional implications on shaping developing cortical networks.

  18. 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.

  19. 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.

  20. 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.

  1. Analyzing electrical activities of pancreatic β cells using mathematical models.

    Science.gov (United States)

    Cha, Chae Young; Powell, Trevor; Noma, Akinori

    2011-11-01

    Bursts of repetitive action potentials are closely related to the regulation of glucose-induced insulin secretion in pancreatic β cells. Mathematical studies with simple β-cell models have established the central principle that the burst-interburst events are generated by the interaction between fast membrane excitation and slow cytosolic components. Recently, a number of detailed models have been developed to simulate more realistic β cell activity based on expanded findings on biophysical characteristics of cellular components. However, their complex structures hinder our intuitive understanding of the underlying mechanisms, and it is becoming more difficult to dissect the role of a specific component out of the complex network. We have recently developed a new detailed model by incorporating most of ion channels and transporters recorded experimentally (the Cha-Noma model), yet the model satisfies the charge conservation law and reversible responses to physiological stimuli. Here, we review the mechanisms underlying bursting activity by applying mathematical analysis tools to representative simple and detailed models. These analyses include time-based simulation, bifurcation analysis and lead potential analysis. In addition, we introduce a new steady-state I-V (ssI-V) curve analysis. We also discuss differences in electrical signals recorded from isolated single cells or from cells maintaining electrical connections within multi-cell preparations. Towards this end, we perform simulations with our detailed pancreatic β-cell model.

  2. 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)

  3. Semantic brain areas are involved in gesture comprehension: An electrical neuroimaging study.

    Science.gov (United States)

    Proverbio, Alice Mado; Gabaro, Veronica; Orlandi, Andrea; Zani, Alberto

    2015-08-01

    While the mechanism of sign language comprehension in deaf people has been widely investigated, little is known about the neural underpinnings of spontaneous gesture comprehension in healthy speakers. Bioelectrical responses to 800 pictures of actors showing common Italian gestures (e.g., emblems, deictic or iconic gestures) were recorded in 14 persons. Stimuli were selected from a wider corpus of 1122 gestures. Half of the pictures were preceded by an incongruent description. ERPs were recorded from 128 sites while participants decided whether the stimulus was congruent. Congruent pictures elicited a posterior P300 followed by late positivity, while incongruent gestures elicited an anterior N400 response. N400 generators were investigated with swLORETA reconstruction. Processing of congruent gestures activated face- and body-related visual areas (e.g., BA19, BA37, BA22), the left angular gyrus, mirror fronto/parietal areas. The incongruent-congruent contrast particularly stimulated linguistic and semantic brain areas, such as the left medial and the superior temporal lobe. PMID:26011745

  4. The electric drive of the BMW Active E; Der elektrische Antrieb des BMW Active E

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Merten; Ueberle, Hendrik; Vogel, Frank [BMW Group, Muenchen (Germany); Merwerth, Joerg [BMW Peugeot Citroen Electrification, Muenchen (Germany)

    2012-07-15

    Following up on its Mini E, BMW is now presenting a further car with an electric powertrain, the BMW ActiveE. Its electric motor develops a power output of 125 kW and 250 Nm of torque. The high-voltage battery with a net energy content of 28 kWh and the drive electronics have both been systematically developed in-house by BMW. In spite of its single-speed transmission, the ActiveE features very good powertrain dynamics due to the use of a special permanently energised synchronous motor. (orig.)

  5. 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.

  6. Infrared optical activity: electric field approaches in time domain.

    Science.gov (United States)

    Rhee, Hanju; Choi, Jun-Ho; Cho, Minhaeng

    2010-12-21

    Vibrational circular dichroism (VCD) spectroscopy provides detailed information about the absolute configurations of chiral molecules including biomolecules and synthetic drugs. This method is the infrared (IR) analogue of the more popular electronic CD spectroscopy that uses the ultraviolet and visible ranges of the electromagnetic spectrum. Because conventional electronic CD spectroscopy measures the difference in signal intensity, problems such as weak signal and low time-resolution can limit its utility. To overcome the difficulties associated with that approach, we have recently developed femtosecond IR optical activity (IOA) spectrometry, which directly measures the IOA free-induction-decay (FID), the impulsive chiroptical IR response that occurs over time. In this Account, we review the time-domain electric field measurement and calculation methods used to simultaneously characterize VCD and related vibrational optical rotatory dispersion (VORD) spectra. Although conventional methods measure the electric field intensity, this vibrational technique is based on a direct phase-and-amplitude measurement of the electric field of the chiroptical signal over time. This method uses a cross-polarization analyzer to carry out heterodyned spectral interferometry. The cross-polarization scheme enables us to selectively remove the achiral background signal, which is the dominant noise component present in differential intensity measurement techniques. Because we can detect the IOA FID signal in a phase-amplitude-sensitive manner, we can directly characterize the time-dependent electric dipole/magnetic dipole response function and the complex chiral susceptibility that contain information about the angular oscillations of charged particles. These parameters yield information about the VCD and VORD spectra. In parallel with such experimental developments, we have also calculated the IOA FID signal and the resulting VCD spectrum. These simulations use a quantum mechanical

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

    Directory of Open Access Journals (Sweden)

    Dr. K. ADALARASU,

    2011-04-01

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

  8. 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 ...

  9. Electrical impedance of mouse brain cortex in vitro from 4.7 kHz to 2.0 MHz.

    Science.gov (United States)

    Wilson, M T; Elbohouty, M; Voss, L J; Steyn-Ross, D A

    2014-02-01

    The electrical impedance of samples of mouse brain cortex has been measured between 4.7 kHz and 2.0 MHz. Brain slices of thickness 400 μm were prepared from two mice. Each slice was placed in either normal artificial cerebrospinal fluid or magnesium-free artificial cerebrospinal fluid; the latter induces seizure-like electrical behaviour. A total of 74 samples of cortex of approximate size 2 mm × 2 mm were then cut from these slices. Each sample in turn was placed between two flat Ag/AgCl electrodes and electrical impedance measured with an Agilent E4980A four-point impedance monitor. The measurements showed two regions of significant dispersion. Circuits based on the Cole-Cole and Fricke models, consisting of inductive, nonlinear capacitive and resistive elements were used to model the behaviour. Distributions of values for each circuit element have been determined for the samples prepared in seizing and non-seizing conditions. Few differences were found between the values of circuit elements between the seizing and non-seizing groups.

  10. Manganese-enhanced magnetic resonance imaging (MEMRI) of brain activity and applications to early detection of brain ischemia.

    Science.gov (United States)

    Aoki, Ichio; Naruse, Shoji; Tanaka, Chuzo

    2004-12-01

    Divalent manganese ion (Mn2+) has been reported to be a useful contrast agent for functional MRI, through a technique named activity-induced manganese-dependent MRI (AIM). In AIM, signal enhancement is related to functional increases in calcium influx, and therefore AIM is, thus far, the only MRI method able to map brain activation in vivo independently of the surrogate hemodynamic changes used in functional MRI. Because of its high signal-to-noise ratio (SNR) and high sensitivity, AIM allows the use of multi-slice or three-dimensional MRI techniques to map functional activity at high spatial resolution. In the present review, we define AIM as a functional MRI tool based on the administration of divalent ionized manganese through an open or disrupted blood-brain barrier (BBB). The adequacy and efficacy of AIM in detecting neural activation is described in light of supporting experiments on inhibition of calcium channels, FOS expression, and on direct comparison to BOLD- and perfusion-based functional MRI. Two main applications of AIM, mapping brain activation in rat somatosensory cortex, as well stroke research based on the well-established middle cerebral artery occlusion model, are described in detail. Methodological problems associated with a strong dependence on anesthetic conditions, potential corruption due to disruption of the BBB, and unspecific increase of the baseline signal due to acoustical noise are discussed. Finally, recommended preparation methods and experimental protocols for AIM are introduced.

  11. 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.

  12. Differential responsiveness of the right parahippocampal region to electrical stimulation in fixed human brains: Implications for historical surgical stimulation studies?

    Science.gov (United States)

    Rouleau, Nicolas; Persinger, Michael A

    2016-07-01

    If structure dictates function within the living human brain, then the persistence of specific responses to weak electric currents in fixed, deceased brains could reflect "hardwired" properties. Different key structures from the left and right hemispheres of brains that had been fixed for over 20years with ethanol-formalin-acetic acid were stimulated with either 1-Hz, 7-Hz, 10-Hz, 20-Hz, or 30-Hz, sine-wave, square-wave, or pulsed currents while needle-recorded quantitative electroencephalographic responses were obtained. Differential responses occurred only within the right hippocampus and parahippocampal gyrus. The right hippocampus displayed frequency-independent increases in gamma power relative to the left hemispheric homologue. The parahippocampal region responded exclusively to 7-Hz pulsed currents with wideband (8-30Hz) power. These profiles are consistent with dynamic connections associated with memory and consciousness and may partially explain the interactions resultant of pulse type and hemisphere for experiential elicitations during the golden age of surgical stimulations. The results also indicate that there may be an essential "hardwiring" within the human brain that is maintained for decades when it is fixed appropriately. PMID:27208828

  13. 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

    2002-01-01

    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

  14. 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...

  15. Task-free MRI predicts individual differences in brain activity during task performance

    NARCIS (Netherlands)

    Tavor, I.; Jones, O.P.; Mars, R.B.; Smith, S.M.; Behrens, T.E.J.; Jbabdi, S.

    2016-01-01

    When asked to perform the same task, different individuals exhibit markedly different patterns of brain activity. This variability is often attributed to volatile factors, such as task strategy or compliance. We propose that individual differences in brain responses are, to a large degree, inherent

  16. 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.

  17. 心身疾病“刚柔辨证”四种证候与脑电慢波改变的相关性研究%Research on relationship of four common syndromes of‘Rigid-Gentle Syndrome Differentiation’ of psychosomatic diseases and δ and θ wave change in brain electrical activity mapping

    Institute of Scientific and Technical Information of China (English)

    张成; 赵志付; 李健

    2015-01-01

    目的:通过观察心身疾病患者脑电信号慢波δ和θ波的功率值改变,探究心身疾病“刚柔辨证”四种常见证候与脑电慢波改变的相关关系。方法“证病结合”“以方测证”为研究方法,采用脑电地形图为技术手段,把经显效方剂对应治疗2~8周后疗效为显效和临床痊愈的“刚柔辨证”主证为心肝火旺、心肝阴虚、肝郁气滞、肝郁脾虚证的患者治疗前脑电信号δ和θ波功率值与健康人对照组脑电信号δ和θ波功率值进行对照分析。其中心肝火旺证20例、心肝阴虚证32例、肝郁气滞证27例、肝郁脾虚证21例和健康人对照组23例。结果心肝阴虚证与正常人对照组比较,δ波在额区和额极区功率值增高(在FP1、F3、F4,P<0.005;在FP2,P<0.05),θ波在除了双颞区之外所有10个脑区功率值增高(P<0.005)。心肝火旺证、肝郁气滞证、肝郁脾虚证与正常人对照组比较,δ波和θ波功率值增高,以前头部为主,但此三组与对照组比较未见显著性差异。结论初步揭示“刚柔辨证”四种常见证候与脑电慢波改变的规律性及特异性表现,初步从脑电生理学角度揭示“刚柔辨证”理论的物质基础和证候实质。%Objective To explore the relationship of four common syndromes of ‘Rigid-Gentle Syndrome Differentiation’ of psychosomatic diseases and δ and θ wave change in brain electrical activity mapping ( BEAM) . Methods Syndromes are the core while diseases are the complement. The accuracy of Syndrome Differentiation has been verifying by the curative effects of fixed traditional Chinese medicine ( TCM) prescription. Each case was summarized by curative effects according to efficacy standards of different diseases. BEAM was used as technical means. Each case has been measured by BEAM before treatment. 100 cases of the four syndromes of‘Hyperactivity of heart-fire and liver-fire’ ,‘Heart and liver yin deficiency ’ ,

  18. Light Stimulation Properties to Influence Brain Activity: A Brain-CoMputer Interface application

    NARCIS (Netherlands)

    Bieger, J.; Garcia Molina, G.

    2010-01-01

    Brain-Computer Interfaces (BCIs) enable people to control appliances without involving the normal output pathways of peripheral nervesand muscles. A particularly promising type of BCI is based on the Steady-State Visual Evoked Potential (SSVEP). Users can selectcommands by focusing their attention o

  19. 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

    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-trimester ......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......-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...... 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...

  20. Can Neural Activity Propagate by Endogenous Electrical Field?

    Science.gov (United States)

    Qiu, Chen; Shivacharan, Rajat S; Zhang, Mingming; Durand, Dominique M

    2015-12-01

    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. PMID:26631463

  1. Effects of various frequency electrical stimulation of the dorsal raphe nucleus on spontaneous firing activities in the rat subthalamic nucleus

    Institute of Scientific and Technical Information of China (English)

    Hongmei Ran; Dongming Gao

    2008-01-01

    BACKGROUND: Some investigations have demonstrated that exogenous 5-hydroxytryptamine increases the spontaneous firing rate of subthalamic nucleus (STN) neurons in the rat brain.OBJECTIVE: To validate the effect of electrical stimulation to the dorsal raphe nucleus (DRN) on the neu-ronal activities of the STN in rats, as well as analyze the differences in the effects of electrical stimulation at various frequencies.DESIGN, TIME AND SETTING: Experiments were performed from March 2007 to June 2007 in the Electrophysiology Laboratory of Liaoning Medical University with a randomized controlled animal study design.MATERIALS: Twenty-four healthy male Sprague-Dawley (SD) rats, weighing 250-350 g, were selected for this study. An A320R constant electrical stimulator was purchased from World Precision Instruments Com-pany (USA); a Spike 2 biological signal acquisition system was purchased from British CED Company. METHODS: Twenty-four SD rats were randomly assigned into a model group and a normal group, with 12 rats in each group. To mimic Parkinson's disease, rats in the model group were injected with 4 μL of 6-hydroxydopamine into the right striatum, then received deep brain stimulation. Rats in the normal group re-ceived deep brain stimulation in same brain region without modeling. Electrical stimulation (width, 0.06 ms; intensity, 0.2-0.6 mA; frequency, 20-130 Hz; train duration, 5 seconds) was delivered to the DRN. MAIN OUTCOME MEASURES: The firing rates of STN neurons were observed by extracellular record-ing using a biological signal acquisition system. RESULTS: DRN-high-frequency stimulation (DRN-HFS) induced excitation in 59% of the STN neurons in the normal group and 50% of the STN neurons in the model group; mean firing rates increased significantly from (7.14± 0.75) and (7.94 ± 0.61) Hz to (11.17 ± 1.49) and (12.11 ± 1.05) Hz, respectively (P < 0.01). Spontaneous firing rate increased significantly in 53% of neurons in normal rats in a frequency

  2. Electrical processes for the treatment of medium active liquid wastes

    International Nuclear Information System (INIS)

    Cross-flow electrokinetic dewatering has been developed on a lab-scale into an effective process for the treatment of such wastes as gravity-settled flocs, or sludges arising from fuel storage. The product may be concentrated to 25-42% solids while still remaining fluid, prior to immobilization - e.g. by addition of cement powder. Complete retention of activity in the concentrate was observed during the treatment of Harwell low-level waste sludges due to the high solids separation factor ( > 104). It is a low pressure, low temperature process - consuming only 0.03-0.13 kWh/L at permeation rates of 0.3-1.5 m/h (depending on the stream), corresponding to 1/67 - 1/15 that needed for evaporation. An advanced electrochemical ion-exchange system has been developed in which ionic material can be electrically adsorbed and eluted by polarity reversal > 1000 times, without any change in performance. Decontamination factors of about 2000 were achieved for Cs removal, up to 75% loading of the exchanger at flow rates of 8 bed volumes/h. Elution into water can give concentrates of >= 0.25 M - with consequent high volume reduction factors. Inorganic ion-exchangers have also demonstrated system selectivity for the removal of specific cations. Overall energy consumption is 3 (1/400 evaporation). Significant cost savings over conventional ion-exchange may accrue from the improved performance under electrical control, and the reduced volumes of waste requiring disposal. (author)

  3. 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.

  4. 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.

  5. 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.

  6. A novel pattern mining approach for identifying cognitive activity in EEG based functional brain networks.

    Science.gov (United States)

    Thilaga, M; Vijayalakshmi, R; Nadarajan, R; Nandagopal, D

    2016-06-01

    The complex nature of neuronal interactions of the human brain has posed many challenges to the research community. To explore the underlying mechanisms of neuronal activity of cohesive brain regions during different cognitive activities, many innovative mathematical and computational models are required. This paper presents a novel Common Functional Pattern Mining approach to demonstrate the similar patterns of interactions due to common behavior of certain brain regions. The electrode sites of EEG-based functional brain network are modeled as a set of transactions and node-based complex network measures as itemsets. These itemsets are transformed into a graph data structure called Functional Pattern Graph. By mining this Functional Pattern Graph, the common functional patterns due to specific brain functioning can be identified. The empirical analyses show the efficiency of the proposed approach in identifying the extent to which the electrode sites (transactions) are similar during various cognitive load states.

  7. 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.

  8. Electric Double-layer Capacitor Based on Activated Carbon Material

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In this study electric double-layer capacitors (EDLCs) based on activated carbon material and organic electrolyte (tetraethyl ammonium tetrafluoroborate) were explored. The fabrication method for EDLC is presented and the performance of EDLC was examined by using the cyclic voltammetry, constant-current charging and discharging technique, electrochemical impedance spectroscopy measurements. Influence of various components and design parameters on the performance of the capacitors were preliminarily investigated. Up to now, EDLC based on carbon materials can deliver 20.7 W/kg at the discharge rate ofI=0.3 mA, together with the energy density of 8.5 Wh/kg. Equivalent series resistance (ESR) is 0.716 Ω.cm2. The specific power of the capacitor is low and further attempts to raise the power capability of the capacitors are necessary. Some considerations are put forward to further improve the performance of EDLC.

  9. 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.

  10. Moving the brain: Neuroimaging motivational changes of deep brain stimulation in obsessive-compulsive disorder

    NARCIS (Netherlands)

    M. Figee

    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 O

  11. Towards brain-activity-controlled information retrieval: Decoding image relevance from MEG signals.

    Science.gov (United States)

    Kauppi, Jukka-Pekka; Kandemir, Melih; Saarinen, Veli-Matti; Hirvenkari, Lotta; Parkkonen, Lauri; Klami, Arto; Hari, Riitta; Kaski, Samuel

    2015-05-15

    We hypothesize that brain activity can be used to control future information retrieval systems. To this end, we conducted a feasibility study on predicting the relevance of visual objects from brain activity. We analyze both magnetoencephalographic (MEG) and gaze signals from nine subjects who were viewing image collages, a subset of which was relevant to a predetermined task. We report three findings: i) the relevance of an image a subject looks at can be decoded from MEG signals with performance significantly better than chance, ii) fusion of gaze-based and MEG-based classifiers significantly improves the prediction performance compared to using either signal alone, and iii) non-linear classification of the MEG signals using Gaussian process classifiers outperforms linear classification. These findings break new ground for building brain-activity-based interactive image retrieval systems, as well as for systems utilizing feedback both from brain activity and eye movements.

  12. 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…

  13. 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. Com

  14. Tasting calories differentially affects brain activation during hunger and satiety

    NARCIS (Netherlands)

    van Rijn, Inge; de Graaf, Cees; Smeets, Paul A M

    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 satiet

  15. 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

  16. Changes in reward-induced brain activation in opiate addicts

    NARCIS (Netherlands)

    Martin-Soelch, C; Chevalley, AF; Kunig, G; Missimer, J; Magyar, S; Mino, A; Schultz, W; Leenders, KL

    2001-01-01

    Many studies indicate a role of the cerebral dopaminergic reward system in addiction. Motivated by these findings, we examined in opiate addicts whether brain regions involved in the reward circuitry also react to human prototypical rewards. We measured regional cerebral blood flow (rCBF) with (H2O)

  17. Brain Activation Associated with Practiced Left Hand Mirror Writing

    Science.gov (United States)

    Kushnir, T.; Arzouan, Y.; Karni, A.; Manor, D.

    2013-01-01

    Mirror writing occurs in healthy children, in various pathologies and occasionally in healthy adults. There are only scant experimental data on the underlying brain processes. Eight, right-handed, healthy young adults were scanned (BOLD-fMRI) before and after practicing left-hand mirror-writing (lh-MW) over seven sessions. They wrote dictated…

  18. Temporal dynamics of musical emotions examined through intersubject synchrony of brain activity.

    OpenAIRE

    Trost, W.; Frühholz, S.; Cochrane, T.; Cojan, Y.; Vuilleumier, P.

    2015-01-01

    To study emotional reactions to music, it is important to consider the temporal dynamics of both affective responses and underlying brain activity. Here, we investigated emotions induced by music using functional magnetic resonance imaging (fMRI) with a data-driven approach based on intersubject correlations (ISC). This method allowed us to identify moments in the music that produced similar brain activity (i.e. synchrony) among listeners under relatively natural listening conditions. Continu...

  19. Changing Balance of Spinal Cord Excitability and Nociceptive Brain Activity in Early Human Development.

    Science.gov (United States)

    Hartley, Caroline; Moultrie, Fiona; Gursul, Deniz; Hoskin, Amy; Adams, Eleri; Rogers, Richard; Slater, Rebeccah

    2016-08-01

    In adults, nociceptive reflexes and behavioral responses are modulated by a network of brain regions via descending projections to the spinal dorsal horn [1]. Coordinated responses to noxious inputs manifest from a balance of descending facilitation and inhibition. In contrast, young infants display exaggerated and uncoordinated limb reflexes [2]. Our understanding of nociceptive processing in the infant brain has been advanced by the use of electrophysiological and hemodynamic imaging [3-6]. From approximately 35 weeks' gestation, nociceptive-specific patterns of brain activity emerge [7], whereas prior to this, non-specific bursts of activity occur in response to noxious, tactile, visual, and auditory stimulation [7-10]. During the preterm period, refinement of spinal cord excitability is also observed: reflex duration shortens, response threshold increases, and improved discrimination between tactile and noxious events occurs [2, 11, 12]. However, the development of descending modulation in human infants remains relatively unexplored. In 40 infants aged 28-42 weeks' gestation, we examined the relationship between nociceptive brain activity and spinal reflex withdrawal activity in response to a clinically essential noxious procedure. Nociceptive-specific brain activity increases in magnitude with gestational age, whereas reflex withdrawal activity decreases in magnitude, duration, and latency across the same developmental period. By recording brain and spinal cord activity in the same infants, we demonstrate that the maturation of nociceptive brain activity is concomitant with the refinement of noxious-evoked limb reflexes. We postulate that, consistent with studies in animals, infant reflexes are influenced by the development of top-down inhibitory modulation from maturing subcortical and cortical brain networks. PMID:27374336

  20. EEG-based local brain activity feedback training—tomographic neurofeedback

    OpenAIRE

    Herbert Bauer

    2014-01-01

    Along with the development of distributed EEG source modeling methods, basic approaches to local brain activity (LBA-) neurofeedback (NF) have been suggested. Meanwhile several attempts using LORETA and sLORETA have been published. This article specifically reports on “EEG-based LBA-feedback training” developed by Bauer et al. (2011). Local brain activity-feedback has the advantage over other sLORETA-based approaches in the way that feedback is exclusively controlled by EEG-generating sources...

  1. Age-Related Shifts in Brain Activity Dynamics during Task Switching

    OpenAIRE

    Jimura, Koji; Braver, Todd S.

    2009-01-01

    Cognitive aging studies have suggested that older adults show declines in both sustained and transient cognitive control processes. However, previous neuroimaging studies have primarily focused on age-related change in the magnitude, but not temporal dynamics, of brain activity. The present study compared brain activity dynamics in healthy old and young adults during task switching. A mixed blocked/event-related functional magnetic resonance imaging design enabled separation of transient and ...

  2. Linking human brain local activity fluctuations to structural and functional network architectures

    OpenAIRE

    Baria, A.T.; Mansour, A; Huang, L.; Baliki, M. N.; Cecchi, G. A.; Mesulam, M M; A. V. Apkarian

    2013-01-01

    Activity of cortical local neuronal populations fluctuates continuously, and a large proportion of these fluctuations are shared across populations of neurons. Here we seek organizational rules that link these two phenomena. Using neuronal activity, as identified by functional MRI (fMRI) and for a given voxel or brain region, we derive a single measure of full bandwidth brain-oxygenation-level-dependent (BOLD) fluctuations by calculating the slope, α, for the log-linear power spectrum. For th...

  3. Regional differences in the electrically stimulated release of endogenous and radioactive adenosine and purine derivatives from rat brain slices.

    Science.gov (United States)

    Pedata, F; Pazzagli, M; Tilli, S; Pepeu, G

    1990-10-01

    The release of both radioactive and endogenous purines was investigated in rat brain cortical, hippocampal and striatal slices at rest and following stimulation with electrical fields. Purines were labelled by incubating the slices with 3H-adenine. The purine efflux at rest and that evoked by electrical stimulation (10 Hz. 5 min) was analyzed by HPLC with ultraviolet absorbance detection. Both radioactive and endogenous purines in the effluent consisted mainly of hypoxanthine, xanthine, inosine and adenosine. No qualitative differences in the composition of the released purines were found in the three areas investigated. Electrical stimulation evoked a net increase in both radioactive and endogenous purine release. However the increase in 3H-adenosine following electrical stimulation was twice as large as that of endogenous adenosine. The electrically evoked release of both radioactive and endogenous purines was greatest in hippocampal slices and progressively smaller in cortical and striatal slices. In the three areas the addition of 0.5 microM tetrodotoxin to the superfusing Krebs solution brought about a similar (83-100%) reduction in evoked 3H-purine and endogenous purine release. Superfusion of the slices with calcium-free Krebs solution containing 0.5 mM EGTA reduced evoked release of 3H-purines by 58-60% and that of endogenous purine components by 54-89%. The results demonstrate similar characteristics for both radioactive and endogenous purine release but indicate that the most recently synthetized adenosine is the most readily available for release. The features of the electrically evoked purine release support a neuronal origin of adenosine and derivatives and are consistent with the hypothesis of discrete regional differences in adenosine neuromodulation. PMID:2255336

  4. Physical parameters activating electrical signal distortions in polluted soils

    Directory of Open Access Journals (Sweden)

    R. Angelini

    2002-06-01

    Full Text Available Laboratory investigations and field measurements show that the electrical behaviour of polluted soils is strongly non-linear at low frequencies. This phenomenon can be related to the class and the amount of pollutants. To measure this non-linearity, we used only monochromatic voltage waveform as input signal and analysed the current signals at first by means of the classical spectral analysis. In particular, the Total Harmonic Distortion % (THD% and the Harmonic Distortion %(? measure the non-linearity level and identify the frequency interval where the non-linear electrical behaviour is activated. This frequency interval can be related to the pollutant molecular size. Open interpretative problems were the following: 1 phase localization of the signal deformation; 2 «local» amplitude of the applied signal activating the distortion, and 3 numerical fit of the distortion. We employed the wavelet analysis to study the phenomenon. The wavelet technique breaks up a signal into shifted and scaled versions of the original wavelet, which is a waveform of limited duration. These features of the wavelets allow us to obtain current components that can be interpreted on the bases of a real physical meaning. By using the wavelet analysis, we obtained the phase localization of the ‘oscillations’ of the details and consequently the phase and amplitude of the applied signal. The sum of nine details provides a good numerical fit of the distorted signal. Starting from the wavelet analysis, we determined the physical conditions activating each distortion, testing some parameters on experimental data. The parameters that resulted most significant are the phase ? of the distortion activation and the product Vin?t (Vs (where ?t is the time interval corresponding to the said ? and Vin is the integral tension applied to the sample on ?t. The latter parameter is in a very good agreement with field data of Advanced Monochromatic Spectral Induced Polarization (AMSIP

  5. Influence of quetiapine fumarate on brain electrical activity during sleep in patients with first-episode schizophrenia%富马酸喹硫平对首发精神分裂症患者睡眠脑电活动的影响

    Institute of Scientific and Technical Information of China (English)

    闫润涛; 马晓燕; 祖国平; 石玉中; 娄百玉; 穆俊林

    2015-01-01

    Objective To investigate the changes of brain electrical activity during sleep after the administration of quetiapine fumarate in patients with first-episode schizophrenia.Methods Forty-three patients with first episode schizophrenia (observation group) underwent polysomnography before and after 4-week treatment with quetiapine fumarate to record the total sleep time,sleep latency,sleep efficiency,awakening time,rapid eye movement sleep latency,rapid eye movement sleep time,percentage of slow-wave sleep stage 1 in total sleep time (S1 %),percentage of slow-wave sleep stage 2 in total sleep time (S2 %),and percentage of slow-wave sleep stage 3 and 4 in total sleep time (SWS%),and were compared with 36 healthy volunteers (control group).Results The total sleep time,sleep latency,sleep efficiency,awakening time,rapid eye movement sleep latency,rapid eye movement sleep time,S1%,S2% and SWS% were (372.4±29.8) min,(31.6±15.2) min,(86.6±9.4)%,(37.5±16.2) min,(64.7±22.6) min,(67.5± 19.8) min,(22.8±9.6) %,(51.3± 16.9)% and (10.2±4.8) % before treatment,and (446.7±25.3) min,(24.9± 11.2) min,(94.5±7.8)%,(21.4±9.7)min,(70.3±18.5) min,(83.1±16.3) min,(11.6±5.7)%,(58.7± 5.1)% and (15.8±4.6)% after 4-week treatment in observation group,and were (462.7±21.3) min,(18.6±9.8) min,(96.3±5.2)%,(14.8±5.5) min,(90.3±14.7) min,(99.1±13.4) min,(9.2±1.7)%,(55.7±4.2)%,(16.7± 4.5)% in control group.Significant differences were found in all indexes above except S2 % between two groups (P<0.05).The total sleep time,sleep efficiency,awakening time,S1%,S2% and SWS% showed significant differences after treatment in comparison with before treatment in observation group (P<0.05).Conclusion Quetiapine fumarate can prolong the total sleep time,improve sleep efficiency,reduce awakening time,shorten slow-wave sleep stage 1,and prolong slow-wave sleep stage 2,3 and 4 for first-episode schizophrenia patients.%目的 探讨首发

  6. 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. PMID:27539656

  7. Optical Control of Living Cells Electrical Activity by Conjugated Polymers.

    Science.gov (United States)

    Martino, Nicola; Bossio, Caterina; Vaquero Morata, Susana; Lanzani, Guglielmo; Antognazza, Maria Rosa

    2016-01-28

    Hybrid interfaces between organic semiconductors and living tissues represent a new tool for in-vitro and in-vivo applications. In particular, conjugated polymers display several optimal properties as substrates for biological systems, such as good biocompatibility, excellent mechanical properties, cheap and easy processing technology, and possibility of deposition on light, thin and flexible substrates. These materials have been employed for cellular interfaces like neural probes, transistors for excitation and recording of neural activity, biosensors and actuators for drug release. Recent experiments have also demonstrated the possibility to use conjugated polymers for all-optical modulation of the electrical activity of cells. Several in-vitro study cases have been reported, including primary neuronal networks, astrocytes and secondary line cells. Moreover, signal photo-transduction mediated by organic polymers has been shown to restore light sensitivity in degenerated retinas, suggesting that these devices may be used for artificial retinal prosthesis in the future. All in all, light sensitive conjugated polymers represent a new approach for optical modulation of cellular activity. In this work, all the steps required to fabricate a bio-polymer interface for optical excitation of living cells are described. The function of the active interface is to transduce the light stimulus into a modulation of the cell membrane potential. As a study case, useful for in-vitro studies, a polythiophene thin film is used as the functional, light absorbing layer, and Human Embryonic Kidney (HEK-293) cells are employed as the biological component of the interface. Practical examples of successful control of the cell membrane potential upon stimulation with light pulses of different duration are provided. In particular, it is shown that both depolarizing and hyperpolarizing effects on the cell membrane can be achieved depending on the duration of the light stimulus. The reported

  8. Optical Control of Living Cells Electrical Activity by Conjugated Polymers.

    Science.gov (United States)

    Martino, Nicola; Bossio, Caterina; Vaquero Morata, Susana; Lanzani, Guglielmo; Antognazza, Maria Rosa

    2016-01-01

    Hybrid interfaces between organic semiconductors and living tissues represent a new tool for in-vitro and in-vivo applications. In particular, conjugated polymers display several optimal properties as substrates for biological systems, such as good biocompatibility, excellent mechanical properties, cheap and easy processing technology, and possibility of deposition on light, thin and flexible substrates. These materials have been employed for cellular interfaces like neural probes, transistors for excitation and recording of neural activity, biosensors and actuators for drug release. Recent experiments have also demonstrated the possibility to use conjugated polymers for all-optical modulation of the electrical activity of cells. Several in-vitro study cases have been reported, including primary neuronal networks, astrocytes and secondary line cells. Moreover, signal photo-transduction mediated by organic polymers has been shown to restore light sensitivity in degenerated retinas, suggesting that these devices may be used for artificial retinal prosthesis in the future. All in all, light sensitive conjugated polymers represent a new approach for optical modulation of cellular activity. In this work, all the steps required to fabricate a bio-polymer interface for optical excitation of living cells are described. The function of the active interface is to transduce the light stimulus into a modulation of the cell membrane potential. As a study case, useful for in-vitro studies, a polythiophene thin film is used as the functional, light absorbing layer, and Human Embryonic Kidney (HEK-293) cells are employed as the biological component of the interface. Practical examples of successful control of the cell membrane potential upon stimulation with light pulses of different duration are provided. In particular, it is shown that both depolarizing and hyperpolarizing effects on the cell membrane can be achieved depending on the duration of the light stimulus. The reported

  9. A New Strategy of Drug Delivery: Electric Field Distribution in Brain Tumor Due to Electroporation

    OpenAIRE

    Shi, Junxing

    2014-01-01

    As the second leading cause of cancer-related deaths in children under 20, and the second leading cause of cancer-related deaths in males aged 20–39, there is a need to seek an effective treatment for brain tumors. While there may be various drugs for brain tumors, the problem is the lack of effective methods of delivery through cell membranes at a very specified and confined region. In order to tackle this specific problem of drug delivery, electroporation is introduced. Electroporation, the...

  10. TMS-EEG: A window into the neurophysiological effects of transcranial electrical stimulation in non-motor brain regions.

    Science.gov (United States)

    Hill, Aron T; Rogasch, Nigel C; Fitzgerald, Paul B; Hoy, Kate E

    2016-05-01

    Transcranial electrical stimulation (tES) techniques are able to induce changes in cortical excitability and plasticity through the administration of weak currents to the brain and are currently being used to manipulate a vast array of cognitive processes. Despite the widespread use of tES technologies within both research and remedial settings, their precise neurophysiological mechanisms of action are not well established outside of the motor cortex. The expanding use of tES within non-motor brain regions highlights the growing need for a more comprehensive understanding of the effects of stimulation across a diversity of cortical locations. The combination of transcranial magnetic stimulation with electroencephalography (TMS-EEG) provides a method of directly probing both local and widespread changes in brain neurophysiology, through the recording of TMS-evoked potentials and cortical oscillations. In this review we explore TMS-EEG as a tool for examining the impact of tES on cortical function and argue that multimodal approaches which combine tES with TMS-EEG could lead to a deeper understanding of the mechanisms which underlie tES-induced cognitive modulation.

  11. The brain activity of pain relief during hypnosis and placebo treatment

    Directory of Open Access Journals (Sweden)

    Svetlana Kirjanen

    2012-05-01

    Full Text Available Placebo treatment and hypnosis are both examples of top-down regulation and are used to treat pain. However, it is unclear whether hypnosis produces anything more than a placebo effect when measuring brain activity changes. This literature review examines research articles published from 1997 onwards regarding the neurophysiology of pain relief during hypnosis or placebo treatments using functional brain imaging (fMRI or PET. The focus was on acute produced nociceptive pain. There seems to be both similarities and clear differences in the brain activity changes between hypnosis and placebo treatments. These results show that hypnosis is not equal to common placebo in terms of brain activity thus questioning the suggestion that the pain reducing properties of hypnosis are just one form of placebo effect.

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

    OpenAIRE

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

    2014-01-01

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

  13. LSD-induced entropic brain activity predicts subsequent personality change.

    Science.gov (United States)

    Lebedev, A V; Kaelen, M; Lövdén, M; Nilsson, J; Feilding, A; Nutt, D J; Carhart-Harris, R L

    2016-09-01

    Personality is known to be relatively stable throughout adulthood. Nevertheless, it has been shown that major life events with high personal significance, including experiences engendered by psychedelic drugs, can have an enduring impact on some core facets of personality. In the present, balanced-order, placebo-controlled study, we investigated biological predictors of post-lysergic acid diethylamide (LSD) changes in personality. Nineteen healthy adults underwent resting state functional MRI scans under LSD (75µg, I.V.) and placebo (saline I.V.). The Revised NEO Personality Inventory (NEO-PI-R) was completed at screening and 2 weeks after LSD/placebo. Scanning sessions consisted of three 7.5-min eyes-closed resting-state scans, one of which involved music listening. A standardized preprocessing pipeline was used to extract measures of sample entropy, which characterizes the predictability of an fMRI time-series. Mixed-effects models were used to evaluate drug-induced shifts in brain entropy and their relationship with the observed increases in the personality trait openness at the 2-week follow-up. Overall, LSD had a pronounced global effect on brain entropy, increasing it in both sensory and hierarchically higher networks across multiple time scales. These shifts predicted enduring increases in trait openness. Moreover, the predictive power of the entropy increases was greatest for the music-listening scans and when "ego-dissolution" was reported during the acute experience. These results shed new light on how LSD-induced shifts in brain dynamics and concomitant subjective experience can be predictive of lasting changes in personality. Hum Brain Mapp 37:3203-3213, 2016. © 2016 Wiley Periodicals, Inc. PMID:27151536

  14. MICROGLIA ACTIVATION AS A BIOMARKER FOR TRAUMATIC BRAIN INJURY

    Directory of Open Access Journals (Sweden)

    Diana G Hernadez-Ontiveros

    2013-03-01

    Full Text Available Traumatic brain injury (TBI has become the signature wound of wars in Afghanistan and Iraq. Injury may result from a mechanical force, a rapid acceleration-deceleration movement, or a blast wave. A cascade of secondary cell death events ensues after the initial injury. In particular, multiple inflammatory responses accompany TBI. A series of inflammatory cytokines and chemokines spreads to normal brain areas juxtaposed to the core impacted tissue. Among the repertoire of immune cells involved, microglia is a key player in propagating inflammation to tissues neighboring the core site of injury. Neuroprotective drug trials in TBI have failed, likely due to their sole focus on abrogating neuronal cell death and ignoring the microglia response despite these inflammatory cells’ detrimental effects on the brain. Another relevant point to consider is the veracity of results of animal experiments due to deficiencies in experimental design, such as incomplete or inadequate method description, data misinterpretation and reporting may introduce bias and give false-positive results. Thus, scientific publications should follow strict guidelines that include randomization, blinding, sample-size estimation and accurate handling of all data (Landis et al., 2012. A prolonged state of inflammation after brain injury may linger for years and predispose patients to develop other neurological disorders, such as Alzheimer’s disease. TBI patients display progressive and long-lasting impairments in their physical, cognitive, behavioral, and social performance. Here, we discuss inflammatory mechanisms that accompany TBI in an effort to increase our understanding of the dynamic pathological condition as the disease evolves over time and begin to translate these findings for defining new and existing inflammation-based biomarkers and treatments for TBI.

  15. Brain activity associated with illusory correlations in animal phobia

    OpenAIRE

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

    2014-01-01

    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 spider...

  16. Active control for performance enhancement of electrically controlled rotor

    Institute of Scientific and Technical Information of China (English)

    Lu Yang; Wang Chao

    2015-01-01

    Electrically controlled rotor (ECR) system has the potential to enhance the rotor perfor-mance 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 perfor-mance 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.

  17. Buckling of Dielectric Elastomeric Plates for Electrically Active Microfludic Pumps

    Science.gov (United States)

    Holmes, Douglas; Tavakol, Behrouz; Bozlar, Michael; Froehlicher, Guillaume; Stone, Howard; Aksay, Ilhan

    2013-11-01

    Fluid flow can be directed and controlled by a variety of mechanisms within industrial and biological environments. Advances in microfluidic technology have required innovative ways to control fluid flow on a small scale, and the ability to actively control fluid flow within microfluidic devices is crucial for advancements in nanofluidics, biomedical fluidic devices, and digital microfluidics. In this work, we present a means for microfluidic control via the electrical actuation of thin, flexible valves within microfluidic channels. These structures consist of a dielectric elastomer confined between two compliant electrodes that can be actively and reversibly buckle out of plane to pump fluids from an applied voltage. The out-of-plane deformation can be quantified using two parameters: net change in surface area and the shape of deformation. Change in surface area depends on the voltage, while the deformation shape, which significantly affects the flow rate, is a function of voltage, and the pressure and volume of the chambers on each side of the thin plate. The use of solid electrodes enables a robust and reversible pumping mechanism that will have will enable advancements in rapid microfluidic diagnostics, adaptive materials, and artificial muscles.

  18. 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.

  19. Visualization and modelling of STLmax topographic brain activity maps.

    Science.gov (United States)

    Mammone, Nadia; Principe, José C; Morabito, Francesco C; Shiau, Deng S; Sackellares, J Chris

    2010-06-15

    This paper evaluates the descriptive power of brain topography based on a dynamical parameter, the Short-Term Maximum Lyapunov Exponent (STLmax), estimated from EEG, for finding out a relationship of STLmax spatial distribution with the onset zone and with the mechanisms leading to epileptic seizures. Our preliminary work showed that visual assessment of STLmax topography exhibited a link with the location of seizure onset zone. The objective of the present work is to model the spatial distribution of STLmax in order to automatically extract these features from the maps. One-hour preictal segments from four long-term continuous EEG recordings (two scalp and two intracranial) were processed and the corresponding STLmax profiles were estimated. The spatial STLmax maps were modelled by a combination of two Gaussians functions. The parameters of the fitted model allow automatic extraction of quantitative information about the spatial distribution of STLmax: the EEG signal recorded from the brain region where seizures originate exhibited low-STLmax levels, long before the seizure onset, in 3 out of 4 patients (1 out of 2 of scalp patients and 2 out of 2 in intracranial patients). Topographic maps extracted directly from the EEG power did not provide useful information about the location, therefore we conclude that the analysis so far carried out suggests the possibility of using a model of STLmax topography as a tool for monitoring the evolution of epileptic brain dynamics. In the future, a more elaborate approach will be investigated in order to improve the specificity of the method.

  20. Dynamic Multiscale Modes of Resting State Brain Activity Detected by Entropy Field Decomposition.

    Science.gov (United States)

    Frank, Lawrence R; Galinsky, Vitaly L

    2016-09-01

    The ability of functional magnetic resonance imaging (FMRI) to noninvasively measure fluctuations in brain activity in the absence of an applied stimulus offers the possibility of discerning functional networks in the resting state of the brain. However, the reconstruction of brain networks from these signal fluctuations poses a significant challenge because they are generally nonlinear and nongaussian and can overlap in both their spatial and temporal extent. Moreover, because there is no explicit input stimulus, there is no signal model with which to compare the brain responses. A variety of techniques have been devised to address this problem, but the predominant approaches are based on the presupposition of statistical properties of complex brain signal parameters, which are unprovable but facilitate the analysis. In this article, we address this problem with a new method, entropy field decomposition, for estimating structure within spatiotemporal data. This method is based on a general information field-theoretic formulation of Bayesian probability theory incorporating prior coupling information that allows the enumeration of the most probable parameter configurations without the need for unjustified statistical assumptions. This approach facilitates the construction of brain activation modes directly from the spatial-temporal correlation structure of the data. These modes and their associated spatial-temporal correlation structure can then be used to generate space-time activity probability trajectories, called functional connectivity pathways, which provide a characterization of functional brain networks. PMID:27391678

  1. Mapping of Brain Activity by Automated Volume Analysis of Immediate Early Genes.

    Science.gov (United States)

    Renier, Nicolas; Adams, Eliza L; Kirst, Christoph; Wu, Zhuhao; Azevedo, Ricardo; Kohl, Johannes; Autry, Anita E; Kadiri, Lolahon; Umadevi Venkataraju, Kannan; Zhou, Yu; Wang, Victoria X; Tang, Cheuk Y; Olsen, Olav; Dulac, Catherine; Osten, Pavel; Tessier-Lavigne, Marc

    2016-06-16

    Understanding how neural information is processed in physiological and pathological states would benefit from precise detection, localization, and quantification of the activity of all neurons across the entire brain, which has not, to date, been achieved in the mammalian brain. We introduce a pipeline for high-speed acquisition of brain activity at cellular resolution through profiling immediate early gene expression using immunostaining and light-sheet fluorescence imaging, followed by automated mapping and analysis of activity by an open-source software program we term ClearMap. We validate the pipeline first by analysis of brain regions activated in response to haloperidol. Next, we report new cortical regions downstream of whisker-evoked sensory processing during active exploration. Last, we combine activity mapping with axon tracing to uncover new brain regions differentially activated during parenting behavior. This pipeline is widely applicable to different experimental paradigms, including animal species for which transgenic activity reporters are not readily available. PMID:27238021

  2. Concomitant treatment of brain metastasis with Whole Brain Radiotherapy [WBRT] and Temozolomide [TMZ] is active and improves Quality of Life

    Directory of Open Access Journals (Sweden)

    Montella Liliana

    2007-01-01

    Full Text Available Abstract Background Brain metastases (BM represent one of the most frequent complications related to cancer, and their treatment continues to evolve. We have evaluated the activity, toxicity and the impact on Quality of Life (QoL of a concomitant treatment with whole brain radiotherapy (WBRT and Temozolomide (TMZ in patients with brain metastases from solid tumors in a prospective Simon two stage study. Methods Fifty-nine patients were enrolled and received 30 Gy WBRT with concomitant TMZ (75 mg/m2/day for ten days, and subsequently TMZ (150 mg/m2/day for up to six cycles. The primary end points were clinical symptoms and radiologic response. Results Five patients had a complete response, 21 patients had a partial response, while 18 patients had stable disease. The overall response rate (45% exceeded the target activity per study design. The median time to progression was 9 months. Median overall survival was 13 months. The most frequent toxicities included grade 3 neutropenia (15% and anemia (13%, and only one patient developed a grade 4 thrombocytopenia. Age, Karnofsky performance status, presence of extracranial metastases and the recursive partitioning analysis (RPA were found to be predictive factors for response in patients. Overall survival (OS and progression-free survival (PFS were dependent on age and on the RPA class. Conclusion We conclude that this treatment is well tolerated, with an encouraging objective response rate, and a significant improvement in quality of life (p

  3. 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.

  4. The use of dendrograms to describe the electrical activity of motoneurons underlying behaviors in leeches

    OpenAIRE

    Juárez-Hernández, León J.; Bisson, Giacomo; Torre, Vincent

    2013-01-01

    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...

  5. Visual and somatic sensory feedback of brain activity for intuitive surgical robot manipulation.

    Science.gov (United States)

    Miura, Satoshi; Matsumoto, Yuya; Kobayashi, Yo; Kawamura, Kazuya; Nakashima, Yasutaka; Fujie, Masakatsu G

    2015-01-01

    This paper presents a method to evaluate the hand-eye coordination of the master-slave surgical robot by measuring the activation of the intraparietal sulcus in users brain activity during controlling virtual manipulation. The objective is to examine the changes in activity of the intraparietal sulcus when the user's visual or somatic feedback is passed through or intercepted. The hypothesis is that the intraparietal sulcus activates significantly when both the visual and somatic sense pass feedback, but deactivates when either visual or somatic is intercepted. The brain activity of three subjects was measured by the functional near-infrared spectroscopic-topography brain imaging while they used a hand controller to move a virtual arm of a surgical simulator. The experiment was performed several times with three conditions: (i) the user controlled the virtual arm naturally under both visual and somatic feedback passed, (ii) the user moved with closed eyes under only somatic feedback passed, (iii) the user only gazed at the screen under only visual feedback passed. Brain activity showed significantly better control of the virtual arm naturally (pmoving with closed eyes or only gazing among all participants. In conclusion, the brain can activate according to visual and somatic sensory feedback agreement.

  6. Neuroprotective potential of molecular hydrogen against perinatal brain injury via suppression of activated microglia.

    Science.gov (United States)

    Imai, Kenji; Kotani, Tomomi; Tsuda, Hiroyuki; Mano, Yukio; Nakano, Tomoko; Ushida, Takafumi; Li, Hua; Miki, Rika; Sumigama, Seiji; Iwase, Akira; Hirakawa, Akihiro; Ohno, Kinji; Toyokuni, Shinya; Takeuchi, Hideyuki; Mizuno, Tetsuya; Suzumura, Akio; Kikkawa, Fumitaka

    2016-02-01

    Exposure to inflammation in utero is related to perinatal brain injury, which is itself associated with high rates of long-term morbidity and mortality in children. Novel therapeutic interventions during the perinatal period are required to prevent inflammation, but its pathogenesis is incompletely understood. Activated microglia are known to play a central role in brain injury by producing a variety of pro-inflammatory cytokines and releasing oxidative products. The study is aimed to investigate the preventative potential of molecular hydrogen (H2), which is an antioxidant and anti-inflammatory agent without mutagenicity. Pregnant ICR mice were injected with lipopolysaccharide (LPS) intraperitoneally on embryonic day 17 to create a model of perinatal brain injury caused by prenatal inflammation. In this model, the effect of maternal administration of hydrogen water (HW) on pups was also evaluated. The levels of pro-inflammatory cytokines, oxidative damage and activation of microglia were determined in the fetal brains. H2 reduced the LPS-induced expression of pro-inflammatory cytokines, oxidative damage and microglial activation in the fetal brains. Next, we investigated how H2 contributes to neuroprotection, focusing on microglia, using primary cultured microglia and neurons. H2 prevented LPS- or cytokine-induced generation of reactive oxidative species by microglia and reduced LPS-induced microglial neurotoxicity. Finally, we identified several molecules influenced by H2, involved in the process of activating microglia. These results suggested that H2 holds promise for the prevention of inflammation related to perinatal brain injury. PMID:26709014

  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. 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.

  9. Brain Activation during Associative Short-Term Memory Maintenance is Not Predictive for Subsequent Retrieval

    Directory of Open Access Journals (Sweden)

    Heiko eBergmann

    2015-09-01

    Full Text Available 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, rather than being confounded by LTM processes, during the maintenance and probe phase of a WM task. We administered a four-pair (faces and houses associative delayed-match-to-sample (WM task using event-related fMRI and a subsequent associative recognition LTM task, using the same stimuli. This enabled us to analyze subsequent memory effects for both the WM and the LTM test by contrasting correctly recognized pairs with incorrect pairs for either task. Critically, with respect to the subsequent WM effect, we computed this analysis exclusively for trials that were forgotten in the subsequent LTM recognition task. Hence, brain activity associated with successful WM processing was less likely to be confounded by incidental LTM formation. The subsequent LTM effect, in contrast, was analyzed exclusively for pairs that previously had been correctly recognized in the WM task, disclosing brain regions involved in successful LTM formation after successful WM processing. Results for the subsequent WM effect showed no significantly activated brain areas for WM maintenance, possibly due to an insensitivity of fMRI to mechanisms underlying active WM maintenance. In contrast, a correct decision at WM probe was linked to activation in the retrieval success network (anterior and posterior midline brain structures. The subsequent LTM analyses revealed greater activation in left dorsolateral prefrontal cortex and posterior parietal cortex in the early phase of the maintenance stage. No supra-threshold activation was found during the WM probe. Together, we obtained clearer insights in which brain regions support successful WM and LTM without the potential confound of the

  10. Metabolic pathways and activity-dependent modulation of glutamate concentration in the human brain.

    Science.gov (United States)

    Mangia, Silvia; Giove, Federico; Dinuzzo, Mauro

    2012-11-01

    Glutamate is one of the most versatile molecules present in the human brain, involved in protein synthesis, energy production, ammonia detoxification, and transport of reducing equivalents. Aside from these critical metabolic roles, glutamate plays a major part in brain function, being not only the most abundant excitatory neurotransmitter, but also the precursor for γ-aminobutyric acid, the predominant inhibitory neurotransmitter. Regulation of glutamate levels is pivotal for normal brain function, as abnormal extracellular concentration of glutamate can lead to impaired neurotransmission, neurodegeneration and even neuronal death. Understanding how the neuron-astrocyte functional and metabolic interactions modulate glutamate concentration during different activation status and under physiological and pathological conditions is a challenging task, and can only be tentatively estimated from current literature. In this paper, we focus on describing the various metabolic pathways which potentially affect glutamate concentration in the brain, and emphasize which ones are likely to produce the variations in glutamate concentration observed during enhanced neuronal activity in human studies.

  11. Raft disorganization leads to reduced plasmin activity in Alzheimer's disease brains.

    Science.gov (United States)

    Ledesma, Maria Dolores; Abad-Rodriguez, José; Galvan, Cristian; Biondi, Elisa; Navarro, Pilar; Delacourte, Andre; Dingwall, Colin; Dotti, Carlos G

    2003-12-01

    The serine protease plasmin can efficiently degrade amyloid peptide in vitro, and is found at low levels in the hippocampus of patients with Alzheimer's disease (AD). The cause of such paucity remains unknown. We show here that the levels of total brain plasminogen and plasminogen-binding molecules are normal in these brain samples, yet plasminogen membrane binding is greatly reduced. Biochemical analysis reveals that the membranes of these brains have a mild, still significant, cholesterol reduction compared to age-matched controls, and anomalous raft microdomains. This was reflected by the loss of raft-enriched proteins, including plasminogen-binding and -activating molecules. Using hippocampal neurons in culture, we demonstrate that removal of a similar amount of membrane cholesterol is sufficient to induce raft disorganization, leading to reduced plasminogen membrane binding and low plasmin activity. These results suggest that brain raft alterations may contribute to AD by rendering the plasminogen system inefficient.

  12. RXPERIMENTAL AND CLINICAL STUDY OF CREATINE KINASE BB ACTIVITY FOR TH E DIAGNOSIS ON BRAIN DAMAGE

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective To study the differential diagnosis o n cerebral concussion and mild cerebral contusion value of the brain type creati n e kinase isoenzyme(CK-BB),and evaluate the seriousness of brain damage and prog nosis of the patients with acute head injury.Methods Chromatographic separating and fluorometric quant ifying technique was used to detect the CK-BB activity in the cerebrospinal flu id(CSF) of 117 patients with acute head injury and 12 patients with increased in tracranial pressure and 20 normal people.Results The CSF-CK-BB activity of the patients with acu te head injury was remarkably higher than that of the normal people and the CSF -CK-BB activity increased with the seriousness of brain damage.There was a clo se relationship between CSF-CK-BB activity and prognosis,and higher activity o f CSF-CK-BB indicated poor prognosis.Conclusion CSF-CK -BB activity could be used as a new index to diagnose brain damage and evaluate the seriousness of brain damage and prognosis.

  13. Fitness, but not physical activity, is related to functional integrity of brain networks associated with aging.

    Science.gov (United States)

    Voss, Michelle W; Weng, Timothy B; Burzynska, Agnieszka Z; Wong, Chelsea N; Cooke, Gillian E; Clark, Rachel; Fanning, Jason; Awick, Elizabeth; Gothe, Neha P; Olson, Erin A; McAuley, Edward; Kramer, Arthur F

    2016-05-01

    Greater physical activity and cardiorespiratory fitness are associated with reduced age-related cognitive decline and lower risk for dementia. However, significant gaps remain in the understanding of how physical activity and fitness protect the brain from adverse effects of brain aging. The primary goal of the current study was to empirically evaluate the independent relationships between physical activity and fitness with functional brain health among healthy older adults, as measured by the functional connectivity of cognitively and clinically relevant resting state networks. To build context for fitness and physical activity associations in older adults, we first demonstrate that young adults have greater within-network functional connectivity across a broad range of cortical association networks. Based on these results and previous research, we predicted that individual differences in fitness and physical activity would be most strongly associated with functional integrity of the networks most sensitive to aging. Consistent with this prediction, and extending on previous research, we showed that cardiorespiratory fitness has a positive relationship with functional connectivity of several cortical networks associated with age-related decline, and effects were strongest in the default mode network (DMN). Furthermore, our results suggest that the positive association of fitness with brain function can occur independent of habitual physical activity. Overall, our findings provide further support that cardiorespiratory fitness is an important factor in moderating the adverse effects of aging on cognitively and clinically relevant functional brain networks.

  14. The origin of net electric currents in solar active regions

    CERN Document Server

    Dalmasse, K; Démoulin, P; Kliem, B; Török, T; Pariat, E

    2015-01-01

    There is a recurring question in solar physics about whether or not electric currents are neutralized in active regions (ARs). This question was recently revisited using three-dimensional (3D) magnetohydrodynamic (MHD) numerical simulations of magnetic flux emergence into the solar atmosphere. Such simulations showed that flux emergence can generate a substantial net current in ARs. Another source of AR currents are photospheric horizontal flows. Our aim is to determine the conditions for the occurrence of net vs. neutralized currents with this second mechanism. Using 3D MHD simulations, we systematically impose line-tied, quasi-static, photospheric twisting and shearing motions to a bipolar potential magnetic field. We find that such flows: (1) produce both {\\it direct} and {\\it return} currents, (2) induce very weak compression currents - not observed in 2.5D - in the ambient field present in the close vicinity of the current-carrying field, and (3) can generate force-free magnetic fields with a net current...

  15. Modeling the dynamics of human brain activity with recurrent neural networks

    OpenAIRE

    Güçlü, Umut; Marcel A J van Gerven

    2016-01-01

    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 transformation of features to responses (response model). While there has been extensive work on developing better feature models, the work on developing better response models has been rather limited. Here, we...

  16. Visual Learning Alters the Spontaneous Activity of the Resting Human Brain: An fNIRS Study

    OpenAIRE

    Haijing Niu; Hao Li; Li Sun; Yongming Su; Jing Huang; Yan Song

    2014-01-01

    Resting-state functional connectivity (RSFC) has been widely used to investigate spontaneous brain activity that exhibits correlated fluctuations. RSFC has been found to be changed along the developmental course and after learning. Here, we investigated whether and how visual learning modified the resting oxygenated hemoglobin (HbO) functional brain connectivity by using functional near-infrared spectroscopy (fNIRS). We demonstrate that after five days of training on an orientation discrimina...

  17. The brain activity of pain relief during hypnosis and placebo treatment

    OpenAIRE

    Svetlana Kirjanen

    2012-01-01

    Placebo treatment and hypnosis are both examples of top-down regulation and are used to treat pain. However, it is unclear whether hypnosis produces anything more than a placebo effect when measuring brain activity changes. This literature review examines research articles published from 1997 onwards regarding the neurophysiology of pain relief during hypnosis or placebo treatments using functional brain imaging (fMRI or PET). The focus was on acute produced nociceptive pain. There seems to b...

  18. Brain Activation Patterns at Exhaustion in Rats That Differ in Inherent Exercise Capacity

    OpenAIRE

    Foley, Teresa E.; Leah R Brooks; Gilligan, Lori J.; Burghardt, Paul R.; Koch, Lauren G.; Britton, Steven L.; Monika Fleshner

    2012-01-01

    In order to further understand the genetic basis for variation in inherent (untrained) exercise capacity, we examined the brains of 32 male rats selectively bred for high or low running capacity (HCR and LCR, respectively). The aim was to characterize the activation patterns of brain regions potentially involved in differences in inherent running capacity between HCR and LCR. Using quantitative in situ hybridization techniques, we measured messenger ribonuclease (mRNA) levels of c-Fos, a mark...

  19. Sex differences in how stress affects brain activity during face viewing

    OpenAIRE

    Mather, Mara; Lighthall, Nichole R.; Nga, Lin; Marissa A Gorlick

    2010-01-01

    Under stress, men tend to withdraw socially while women seek social support. The current functional magnetic resonance imaging study indicates that stress also affects brain activity while viewing emotional faces differently for men and women. Fusiform face area (FFA) response to faces was diminished by acute stress in males but increased by stress in females. Furthermore, among stressed males viewing angry faces, brain regions involved in interpreting and understanding others' emotions (the ...

  20. 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.

  1. Electrical stimulation alleviates depressive-like behaviors of rats: investigation of brain targets and potential mechanisms.

    Science.gov (United States)

    Lim, L W; Prickaerts, J; Huguet, G; Kadar, E; Hartung, H; Sharp, T; Temel, Y

    2015-01-01

    Deep brain stimulation (DBS) is a promising therapy for patients with refractory depression. However, key questions remain with regard to which brain target(s) should be used for stimulation, and which mechanisms underlie the therapeutic effects. Here, we investigated the effect of DBS, with low- and high-frequency stimulation (LFS, HFS), in different brain regions (ventromedial prefrontal cortex, vmPFC; cingulate cortex, Cg; nucleus accumbens (NAc) core or shell; lateral habenula, LHb; and ventral tegmental area) on a variety of depressive-like behaviors using rat models. In the naive animal study, we found that HFS of the Cg, vmPFC, NAc core and LHb reduced anxiety levels and increased motivation for food. In the chronic unpredictable stress model, there was a robust depressive-like behavioral phenotype. Moreover, vmPFC HFS, in a comparison of all stimulated targets, produced the most profound antidepressant effects with enhanced hedonia, reduced anxiety and decreased forced-swim immobility. In the following set of electrophysiological and histochemical experiments designed to unravel some of the underlying mechanisms, we found that vmPFC HFS evoked a specific modulation of the serotonergic neurons in the dorsal raphe nucleus (DRN), which have long been linked to mood. Finally, using a neuronal mapping approach by means of c-Fos expression, we found that vmPFC HFS modulated a brain circuit linked to the DRN and known to be involved in affect. In conclusion, HFS of the vmPFC produced the most potent antidepressant effects in naive rats and rats subjected to stress by mechanisms also including the DRN. PMID:25826110

  2. Cognitive activity, cognitive function, and brain diffusion characteristics in old age.

    Science.gov (United States)

    Arfanakis, Konstantinos; Wilson, Robert S; Barth, Christopher M; Capuano, Ana W; Vasireddi, Anil; Zhang, Shengwei; Fleischman, Debra A; Bennett, David A

    2016-06-01

    The objective of this work was to test the hypotheses that a) more frequent cognitive activity in late life is associated with higher brain diffusion anisotropy and lower trace of the diffusion tensor, and b) brain diffusion characteristics partially mediate the association of late life cognitive activity with cognition. As part of a longitudinal cohort study, 379 older people without dementia rated their frequency of participation in cognitive activities, completed a battery of cognitive function tests, and underwent diffusion tensor imaging. We used tract-based spatial statistics to test the association between late life cognitive activity and brain diffusion characteristics. Clusters with statistically significant findings defined regions of interest in which we tested the hypothesis that diffusion characteristics partially mediate the association of late life cognitive activity with cognition. More frequent cognitive activity in late life was associated with higher level of global cognition after adjustment for age, sex, education, and indicators of early life cognitive enrichment (p = 0.001). More frequent cognitive activity was also related to higher fractional anisotropy in the left superior and inferior longitudinal fasciculi, left fornix, and corpus callosum, and lower trace in the thalamus (p cognitive activity with cognition was reduced by as much as 26 %. These findings suggest that the association of late life cognitive activity with cognition may be partially mediated by brain diffusion characteristics.

  3. Brain Basics

    Medline Plus

    Full Text Available ... Life Brain Basics in Real Life—How Depression affects the Brain Meet Sarah Sarah is a middle-aged woman ... new memories. hypothalmic-pituitary-adrenal (HPA) axis —A brain-body ... stress. impulse —An electrical communication signal sent between neurons ...

  4. Electric passenger and goods vehicles: A review of UK activities

    International Nuclear Information System (INIS)

    The production of electric-powered vehicles has been reduced to only a few hundred, after several thousand had been produced in Great Britain during the past five years. In the framework of this article, the different components of electric-powered vehicles are being examined regarding the economical situation: such as the vehicle itself, the batteries, the motor and the vehicle control. (BWI)

  5. Rapid and Quantitative Assay of Amyloid-Seeding Activity in Human Brains Affected with Prion Diseases.

    Directory of Open Access Journals (Sweden)

    Hanae Takatsuki

    Full Text Available The infectious agents of the transmissible spongiform encephalopathies are composed of amyloidogenic prion protein, PrPSc. Real-time quaking-induced conversion can amplify very small amounts of PrPSc seeds in tissues/body fluids of patients or animals. Using this in vitro PrP-amyloid amplification assay, we quantitated the seeding activity of affected human brains. End-point assay using serially diluted brain homogenates of sporadic Creutzfeldt-Jakob disease patients demonstrated that 50% seeding dose (SD50 is reached approximately 10(10/g brain (values varies 10(8.79-10.63/g. A genetic case (GSS-P102L yielded a similar level of seeding activity in an autopsy brain sample. The range of PrPSc concentrations in the samples, determined by dot-blot assay, was 0.6-5.4 μg/g brain; therefore, we estimated that 1 SD50 unit was equivalent to 0.06-0.27 fg of PrPSc. The SD50 values of the affected brains dropped more than three orders of magnitude after autoclaving at 121°C. This new method for quantitation of human prion activity provides a new way to reduce the risk of iatrogenic prion transmission.

  6. Electromagnetic pulse activated brain microglia via the p38 MAPK pathway.

    Science.gov (United States)

    Yang, Long-Long; Zhou, Yan; Tian, Wei-Dong; Li, Hai-Juan; Kang-Chu-Li; Miao, Xia; An, Guang-Zhou; Wang, Xiao-Wu; Guo, Guo-Zhen; Ding, Gui-Rong

    2016-01-01

    Previously, we found that electromagnetic pulses (EMP) induced an increase in blood brain barrier permeability and the leakage of albumin from blood into brain tissue. Albumin is known to activate microglia cells. Thus, we hypothesised that microglia activation could occur in the brain after EMP exposure. To test this hypothesis, the morphology and secretory function of microglia cells, including the expression of OX-42 (a marker of microglia activation), and levels of TNF-α, IL-10, IL-1β, and NO were determined in the rat cerebral cortex after EMP exposure. In addition, to examine the signalling pathway of EMP-induced microglia activation, protein and phosphorylated protein levels of p38, JNK and ERK were determined. It was found that the expression of OX-42increased significantly at 1, 6 and 12h (paffect its secretory function both in vivo and in vitro, and the p38 pathway is involved in this process. PMID:26688329

  7. Anticipation of monetary and social reward differently activates mesolimbic brain structures in men and women.

    Science.gov (United States)

    Spreckelmeyer, Katja N; Krach, Sören; Kohls, Gregor; Rademacher, Lena; Irmak, Arda; Konrad, Kerstin; Kircher, Tilo; Gründer, Gerhard

    2009-06-01

    Motivation for goal-directed behaviour largely depends on the expected value of the anticipated reward. The aim of the present study was to examine how different levels of reward value are coded in the brain for two common forms of human reward: money and social approval. To account for gender differences 16 male and 16 female participants performed an incentive delay task expecting to win either money or positive social feedback. fMRI recording during the anticipation phase revealed proportional activation of neural structures constituting the human reward system for increasing levels of reward, independent of incentive type. However, in men activation in the prospect of monetary rewards encompassed a wide network of mesolimbic brain regions compared to only limited activation for social rewards. In contrast, in women, anticipation of either incentive type activated identical brain regions. Our findings represent an important step towards a better understanding of motivated behaviour by taking into account individual differences in reward valuation. PMID:19174537

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

    Institute of Scientific and Technical Information of China (English)

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

    2009-01-01

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

  9. Brain activation-based sexual orientation in female-to-male transsexuals.

    Science.gov (United States)

    Kim, T-H; Kim, G-W; Kim, S-K; Jeong, G-W

    2016-01-01

    This study was performed to identify the sexual orientation in association with brain activation pattern in response to visual erotic stimuli in female-to-male (FtM) transsexuals by using functional magnetic resonance imaging (fMRI). Eleven FtM transsexuals who have had sex-reassignment surgery to alter their natal bodies with the gender-identity disorder were participated. Brain activation for sexual orientation was induced by visual stimuli with female and male erotic nude pictures compared with emotionally-neutral pictures. During viewing the erotic female pictures, the brain areas dominantly activated consist of the superior frontal gyrus, supplementary motor area, anterior/median cingulate gyri and hypothalamus, whereas during viewing male pictures, the brain areas with predominant activities were the middle frontal gyrus, precentral gyrus, middle temporal gyrus, fusiform gyrus, angular gyrus, precuneus, superior/middle occipital gyri, cerebellar cortex and vermis. These findings demonstrate that the brain activation patterns induced by viewing male or female erotic pictures show some correlation to the sexual orientation opposite to the genetic sex in FtM transsexuals. This study would be helpful to understand the neural mechanism associated with visual sexual arousal in patients with gender disorder. PMID:26581912

  10. High-throughput mapping of brain-wide activity in awake and drug-responsive vertebrates.

    Science.gov (United States)

    Lin, Xudong; Wang, Shiqi; Yu, Xudong; Liu, Zhuguo; Wang, Fei; Li, Wai Tsun; Cheng, Shuk Han; Dai, Qiuyun; Shi, Peng

    2015-02-01

    The reconstruction of neural activity across complete neural circuits, or brain activity mapping, has great potential in both fundamental and translational neuroscience research. Larval zebrafish, a vertebrate model, has recently been demonstrated to be amenable to whole brain activity mapping in behaving animals. Here we demonstrate a microfluidic array system ("Fish-Trap") that enables high-throughput mapping of brain-wide activity in awake larval zebrafish. Unlike the commonly practiced larva-processing methods using a rigid gel or a capillary tube, which are laborious and time-consuming, the hydrodynamic design of our microfluidic chip allows automatic, gel-free, and anesthetic-free processing of tens of larvae for microscopic imaging with single-cell resolution. Notably, this system provides the capability to directly couple pharmaceutical stimuli with real-time recording of neural activity in a large number of animals, and the local and global effects of pharmacoactive drugs on the nervous system can be directly visualized and evaluated by analyzing drug-induced functional perturbation within or across different brain regions. Using this technology, we tested a set of neurotoxin peptides and obtained new insights into how to exploit neurotoxin derivatives as therapeutic agents. The novel and versatile "Fish-Trap" technology can be readily unitized to study other stimulus (optical, acoustic, or physical) associated functional brain circuits using similar experimental strategies.

  11. 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.

  12. Whitening of Background Brain Activity via Parametric Modeling

    Directory of Open Access Journals (Sweden)

    Nidal Kamel

    2007-01-01

    Full Text Available Several signal subspace techniques have been recently suggested for the extraction of the visual evoked potential signals from brain background colored noise. The majority of these techniques assume the background noise as white, and for colored noise, it is suggested to be whitened, without further elaboration on how this might be done. In this paper, we investigate the whitening capabilities of two parametric techniques: a direct one based on Levinson solution of Yule-Walker equations, called AR Yule-Walker, and an indirect one based on the least-squares solution of forward-backward linear prediction (FBLP equations, called AR-FBLP. The whitening effect of the two algorithms is investigated with real background electroencephalogram (EEG colored noise and compared in time and frequency domains.

  13. Activity in human reward-sensitive brain areas in strongly context dependent

    NARCIS (Netherlands)

    Nieuwenhuis, S.; Heslenfeld, D.J.; Mars, R.B.; Alting von Geusau, N.J.; Holroyd, C.B.; Yeung, N.

    2005-01-01

    Functional neuroimaging research in humans has identified a number of brain areas that are activated by the delivery of primary and secondary reinforcers. The present study investigated how activity in these reward-sensitive regions is modulated by the context in which rewards and punishments are ex

  14. Optical Topography of Evoked Brain Activity during Mental Tasks Involving Whole Number Operations

    Science.gov (United States)

    Ortiz, Enrique

    2014-01-01

    Students start to memorize arithmetic facts from early elementary school mathematics activities. Their fluency or lack of fluency with these facts could affect their efforts as they carry out mental calculations as adults. This study investigated participants' levels of brain activation and possible reasons for these levels as they solved…

  15. 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.

  16. Electrical brain responses in language-impaired children reveal grammar-specific deficits.

    Directory of Open Access Journals (Sweden)

    Elisabeth Fonteneau

    Full Text Available BACKGROUND: 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. METHODS AND FINDINGS: 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. CONCLUSIONS: 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. 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.

  18. Adaptive intesration of local resion information to detect fine-scale brain activity patterns

    Institute of Scientific and Technical Information of China (English)

    ZHEN ZongLei; TIAN Jie; ZHANG Hui

    2008-01-01

    With the rapid development of functional magnetic resonance imaging (fMRI) technology, the spatial resolution of fMRI data is continuously growing. This pro-vides us the possibility to detect the fine-scale patterns of brain activities. The es-tablished univariate and multivariate methods to analyze fMRI data mostly focus on detecting the activation blobs without considering the distributed fine-scale pat-terns within the blobs. To improve the sensitivity of the activation detection, in this paper, multivariate statistical method and univariate statistical method are com-bined to discover the fine-grained activity patterns. For one voxel in the brain, a local homogenous region is constructed. Then, time courses from the local ho-mogenous region are integrated with multivariate statistical method. Univariate statistical method is finally used to construct the interests of statistic for that voxel. The approach has explicitly taken into account the structures of both activity pat-terns and existing noise of local brain regions. Therefore, it could highlight the fine-scale activity patterns of the local regions. Experiments with simulated and real fMRI data demonstrate that the proposed method dramatically increases the sensitivity of detection of fine-scale brain activity patterns which contain the subtle information about experimental conditions.

  19. Ethanol-Induced Neurodegeneration and Glial Activation in the Developing Brain

    Directory of Open Access Journals (Sweden)

    Mariko Saito

    2016-08-01

    Full Text Available Ethanol induces neurodegeneration in the developing brain, which may partially explain the long-lasting adverse effects of prenatal ethanol exposure in fetal alcohol spectrum disorders (FASD. While animal models of FASD show that ethanol-induced neurodegeneration is associated with glial activation, the relationship between glial activation and neurodegeneration has not been clarified. This review focuses on the roles of activated microglia and astrocytes in neurodegeneration triggered by ethanol in rodents during the early postnatal period (equivalent to the third trimester of human pregnancy. Previous literature indicates that acute binge-like ethanol exposure in postnatal day 7 (P7 mice induces apoptotic neurodegeneration, transient activation of microglia resulting in phagocytosis of degenerating neurons, and a prolonged increase in glial fibrillary acidic protein-positive astrocytes. In our present study, systemic administration of a moderate dose of lipopolysaccharides, which causes glial activation, attenuates ethanol-induced neurodegeneration. These studies suggest that activation of microglia and astrocytes by acute ethanol in the neonatal brain may provide neuroprotection. However, repeated or chronic ethanol can induce significant proinflammatory glial reaction and neurotoxicity. Further studies are necessary to elucidate whether acute or sustained glial activation caused by ethanol exposure in the developing brain can affect long-lasting cellular and behavioral abnormalities observed in the adult brain.

  20. Oxytocin receptor gene and racial ingroup bias in empathy-related brain activity.

    Science.gov (United States)

    Luo, Siyang; Li, Bingfeng; Ma, Yina; Zhang, Wenxia; Rao, Yi; Han, Shihui

    2015-04-15

    The human brain responds more strongly to racial ingroup than outgroup individuals' pain. This racial ingroup bias varies across individuals and has been attributed to social experiences. What remains unknown is whether the racial ingroup bias in brain activity is associated with a genetic polymorphism. We investigated genetic associations of racial ingroup bias in the brain activity to racial ingroup and outgroup faces that received painful or non-painful stimulations by scanning A/A and G/G homozygous of the oxytocin receptor gene polymorphism (OXTR rs53576) using functional MRI. We found that G/G compared to A/A individuals showed stronger activity in the anterior cingulate and supplementary motor area (ACC/SMA) in response to racial ingroup members' pain, whereas A/A relative to G/G individuals exhibited greater activity in the nucleus accumbens (NAcc) in response to racial outgroup members' pain. Moreover, the racial ingroup bias in ACC/SMA activity positively predicted participants' racial ingroup bias in implicit attitudes and NAcc activity to racial outgroup individuals' pain negatively predicted participants' motivations to reduce racial outgroup members' pain. Our results suggest that the two variants of OXTR rs53576 are associated with racial ingroup bias in brain activities that are linked to implicit attitude and altruistic motivation, respectively. PMID:25637390

  1. Adaptive integration of local region information to detect fine-scale brain activity patterns

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    With the rapid development of functional magnetic resonance imaging (fMRI) technology, the spatial resolution of fMRI data is continuously growing. This pro- vides us the possibility to detect the fine-scale patterns of brain activities. The es- tablished univariate and multivariate methods to analyze fMRI data mostly focus on detecting the activation blobs without considering the distributed fine-scale pat- terns within the blobs. To improve the sensitivity of the activation detection, in this paper, multivariate statistical method and univariate statistical method are com- bined to discover the fine-grained activity patterns. For one voxel in the brain, a local homogenous region is constructed. Then, time courses from the local ho- mogenous region are integrated with multivariate statistical method. Univariate statistical method is finally used to construct the interests of statistic for that voxel. The approach has explicitly taken into account the structures of both activity pat- terns and existing noise of local brain regions. Therefore, it could highlight the fine-scale activity patterns of the local regions. Experiments with simulated and real fMRI data demonstrate that the proposed method dramatically increases the sensitivity of detection of fine-scale brain activity patterns which contain the subtle information about experimental conditions.

  2. On the Modulation of Brain Activation During Simulated Weight Bearing in Supine Gait-Like Stepping.

    Science.gov (United States)

    Jaeger, Lukas; Marchal-Crespo, Laura; Wolf, Peter; Luft, Andreas R; Riener, Robert; Michels, Lars; Kollias, Spyros

    2016-01-01

    To date, the neurophysiological correlates of muscle activation required for weight bearing during walking are poorly understood although, a supraspinal involvement has been discussed in the literature for many years. The present study investigates the effect of simulated ground reaction forces (0, 20, and 40% of individual body weight) on brain activation in sixteen healthy participants. A magnetic resonance compatible robot was applied to render three different levels of load against the feet of the participants during active and passive gait-like stepping movements. Brain activation was analyzed by the means of voxel-wise whole brain analysis as well as by a region-of-interest analysis. A significant modulation of brain activation in sensorimotor areas by the load level could neither be demonstrated during active nor during passive stepping. These observations suggest that the regulation of muscle activation under different weight-bearing conditions during stepping occurs at the level of spinal circuitry or the brainstem rather than at the supraspinal level.

  3. Brain activation patterns at exhaustion in rats that differ in inherent exercise capacity.

    Directory of Open Access Journals (Sweden)

    Teresa E Foley

    Full Text Available In order to further understand the genetic basis for variation in inherent (untrained exercise capacity, we examined the brains of 32 male rats selectively bred for high or low running capacity (HCR and LCR, respectively. The aim was to characterize the activation patterns of brain regions potentially involved in differences in inherent running capacity between HCR and LCR. Using quantitative in situ hybridization techniques, we measured messenger ribonuclease (mRNA levels of c-Fos, a marker of neuronal activation, in the brains of HCR and LCR rats after a single bout of acute treadmill running (7.5-15 minutes, 15° slope, 10 m/min or after treadmill running to exhaustion (15-51 minutes, 15° slope, initial velocity 10 m/min. During verification of trait differences, HCR rats ran six times farther and three times longer prior to exhaustion than LCR rats. Running to exhaustion significantly increased c-Fos mRNA activation of several brain areas in HCR, but LCR failed to show significant elevations of c-Fos mRNA at exhaustion in the majority of areas examined compared to acutely run controls. Results from these studies suggest that there are differences in central c-Fos mRNA expression, and potential brain activation patterns, between HCR and LCR rats during treadmill running to exhaustion and these differences could be involved in the variation in inherent running capacity between lines.

  4. Brain activation patterns at exhaustion in rats that differ in inherent exercise capacity.

    Science.gov (United States)

    Foley, Teresa E; Brooks, Leah R; Gilligan, Lori J; Burghardt, Paul R; Koch, Lauren G; Britton, Steven L; Fleshner, Monika

    2012-01-01

    In order to further understand the genetic basis for variation in inherent (untrained) exercise capacity, we examined the brains of 32 male rats selectively bred for high or low running capacity (HCR and LCR, respectively). The aim was to characterize the activation patterns of brain regions potentially involved in differences in inherent running capacity between HCR and LCR. Using quantitative in situ hybridization techniques, we measured messenger ribonuclease (mRNA) levels of c-Fos, a marker of neuronal activation, in the brains of HCR and LCR rats after a single bout of acute treadmill running (7.5-15 minutes, 15° slope, 10 m/min) or after treadmill running to exhaustion (15-51 minutes, 15° slope, initial velocity 10 m/min). During verification of trait differences, HCR rats ran six times farther and three times longer prior to exhaustion than LCR rats. Running to exhaustion significantly increased c-Fos mRNA activation of several brain areas in HCR, but LCR failed to show significant elevations of c-Fos mRNA at exhaustion in the majority of areas examined compared to acutely run controls. Results from these studies suggest that there are differences in central c-Fos mRNA expression, and potential brain activation patterns, between HCR and LCR rats during treadmill running to exhaustion and these differences could be involved in the variation in inherent running capacity between lines. PMID:23028992

  5. Assessment of glutamine synthetase activity by [13N]ammonia uptake in living rat brain.

    Science.gov (United States)

    Momosaki, Sotaro; Ito, Miwa; Tonomura, Misato; Abe, Kohji

    2015-01-01

    Glutamine synthetase (GS) plays an important role in glutamate neurotransmission or neurological disorder in the brain. [(13) N]Ammonia blood flow tracer has been reported to be metabolically trapped in the brain via the glutamate-glutamine pathway. The present study investigated the effect of an inhibitor of GS on [(13) N]ammonia uptake in order to clarify the feasibility of measuring GS activity in the living brain. l-Methionine sulfoximine (MSO), a selective GS inhibitor was microinjected into the ipsilateral striatum in rats. [(13) N]Ammonia uptake was quantified by autoradiography method as well as small animal positron emission tomography (PET) scans. The GS activity of the brain homogenate was assayed from the γ-glutamyl transferase reaction. Autoradiograms showed a decrease of [(13) N]ammonia radioactivity on the MSO-injected side compared with the saline-injected side of the striatum. This reduction could be detected with a small animal PET scanner. MSO had no effect on cerebral blood flow measured by uptake of [(15) O]H2 O. The reduction of [(13) N]ammonia uptake was closely related to the results of GS activity assay. These results indicated that [(13) N]ammonia may enable measurement of GS activity in the living brain.

  6. Objectively Measured Physical Activity Is Associated with Brain Volumetric Measurements in Multiple Sclerosis

    Directory of Open Access Journals (Sweden)

    Rachel E. Klaren

    2015-01-01

    Full Text Available Background. Little is known about physical activity and its association with volumes of whole brain gray matter and white matter and deep gray matter structures in persons with multiple sclerosis (MS. Purpose. This study examined the association between levels of physical activity and brain volumetric measures from magnetic resonance imaging (MRI in MS. Method. 39 persons with MS wore an accelerometer for a 7-day period and underwent a brain MRI. Normalized GM volume (NGMV, normalized WM volume (NWMV, and deep GM structures were calculated from 3D T1-weighted structural brain images. We conducted partial correlations (pr controlling for demographic and clinical variables. Results. Moderate-to-vigorous physical activity (MVPA was significantly associated with NGMV (pr=0.370, p<0.05, NWMV (pr=0.433, p<0.01, hippocampus (pr=0.499, p<0.01, thalamus (pr=0.380, p<0.05, caudate (pr=0.539, p<0.01, putamen (pr=0.369, p<0.05, and pallidum (pr=0.498, p<0.01 volumes, when controlling for sex, age, clinical course of MS, and Expanded Disability Status Scale score. There were no associations between sedentary and light physical activity with MRI outcomes. Conclusion. Our results provide the first evidence that MVPA is associated with volumes of whole brain GM and WM and deep GM structures that are involved in motor and cognitive functions in MS.

  7. Objectively Measured Physical Activity Is Associated with Brain Volumetric Measurements in Multiple Sclerosis

    Science.gov (United States)

    Klaren, Rachel E.; Hubbard, Elizabeth A.; Motl, Robert W.; Pilutti, Lara A.; Wetter, Nathan C.; Sutton, Bradley P.

    2015-01-01

    Background. Little is known about physical activity and its association with volumes of whole brain gray matter and white matter and deep gray matter structures in persons with multiple sclerosis (MS). Purpose. This study examined the association between levels of physical activity and brain volumetric measures from magnetic resonance imaging (MRI) in MS. Method. 39 persons with MS wore an accelerometer for a 7-day period and underwent a brain MRI. Normalized GM volume (NGMV), normalized WM volume (NWMV), and deep GM structures were calculated from 3D T1-weighted structural brain images. We conducted partial correlations (pr) controlling for demographic and clinical variables. Results. Moderate-to-vigorous physical activity (MVPA) was significantly associated with NGMV (pr = 0.370, p < 0.05), NWMV (pr = 0.433, p < 0.01), hippocampus (pr = 0.499, p < 0.01), thalamus (pr = 0.380, p < 0.05), caudate (pr = 0.539, p < 0.01), putamen (pr = 0.369, p < 0.05), and pallidum (pr = 0.498, p < 0.01) volumes, when controlling for sex, age, clinical course of MS, and Expanded Disability Status Scale score. There were no associations between sedentary and light physical activity with MRI outcomes. Conclusion. Our results provide the first evidence that MVPA is associated with volumes of whole brain GM and WM and deep GM structures that are involved in motor and cognitive functions in MS. PMID:26146460

  8. In Vivo Mesoscopic Voltage-Sensitive Dye Imaging of Brain Activation

    Science.gov (United States)

    Tang, Qinggong; Tsytsarev, Vassiliy; Frank, Aaron; Wu, Yalun; Chen, Chao-Wei; Erzurumlu, Reha S.; Chen, Yu

    2016-04-01

    Functional mapping of brain activity is important in elucidating how neural networks operate in the living brain. The whisker sensory system of rodents is an excellent model to study peripherally evoked neural activity in the central nervous system. Each facial whisker is represented by discrete modules of neurons all along the pathway leading to the neocortex. These modules are called “barrels” in layer 4 of the primary somatosensory cortex. Their location (approximately 300-500 μm below cortical surface) allows for convenient imaging of whisker-evoked neural activity in vivo. Fluorescence laminar optical tomography (FLOT) provides depth-resolved fluorescence molecular information with an imaging depth of a few millimeters. Angled illumination and detection configurations can improve both resolution and penetration depth. We applied angled FLOT (aFLOT) to record 3D neural activities evoked in the whisker system of mice by deflection of a single whisker in vivo. A 100 μm capillary and a pair of microelectrodes were inserted to the mouse brain to test the capability of the imaging system. The results show that it is possible to obtain 3D functional maps of the sensory periphery in the brain. This approach can be broadly applicable to functional imaging of other brain structures.

  9. CB2 Receptor Activation Inhibits Melanoma Cell Transmigration through the Blood-Brain Barrier

    Directory of Open Access Journals (Sweden)

    János Haskó

    2014-05-01

    Full Text Available During parenchymal brain metastasis formation tumor cells need to migrate through cerebral endothelial cells, which form the morphological basis of the blood-brain barrier (BBB. The mechanisms of extravasation of tumor cells are highly uncharacterized, but in some aspects recapitulate the diapedesis of leukocytes. Extravasation of leukocytes through the BBB is decreased by the activation of type 2 cannabinoid receptors (CB2; therefore, in the present study we sought to investigate the role of CB2 receptors in the interaction of melanoma cells with the brain endothelium. First, we identified the presence of CB1, CB2(A, GPR18 (transcriptional variant 1 and GPR55 receptors in brain endothelial cells, while melanoma cells expressed CB1, CB2(A, GPR18 (transcriptional variants 1 and 2, GPR55 and GPR119. We observed that activation of CB2 receptors with JWH-133 reduced the adhesion of melanoma cells to the layer of brain endothelial cells. JWH-133 decreased the transendothelial migration rate of melanoma cells as well. Our results suggest that changes induced in endothelial cells are critical in the mediation of the effect of CB2 agonists. Our data identify CB2 as a potential target in reducing the number of brain metastastes originating from melanoma.

  10. Active RF Pulse Compression using Electrically Controlled Semiconductor Switches

    Energy Technology Data Exchange (ETDEWEB)

    Guo, J.; Tantawi, S.G.; /SLAC

    2008-01-30

    In this paper, we will present our recent results on the research of the ultra-fast high power RF switches based on silicon. We have developed a switch module at X-band which can use a silicon window as the switch. The switching is realized by generation of carriers in the bulk silicon. The carriers can be generated electrically or/and optically. The electrically controlled switches use PIN diodes to inject carrier. We have built the PIN diode switches at X-band, with <300ns switching time. The optically controlled switches use powerful lasers to excite carriers. By combining the laser excitation and electrical carrier generation, significant reduction in the required power of both the laser and the electrical driver is expected. High power test is under going.

  11. Explorative investigation of biomarkers of brain damage and coagulation system activation in clinical stroke differentiation

    DEFF Research Database (Denmark)

    Undén, Johan; Strandberg, Karin; Malm, Jan;

    2009-01-01

    INTRODUCTION: A simple and accurate method of differentiating ischemic stroke and intracerebral hemorrhage (ICH) is potentially useful to facilitate acute therapeutic management. Blood measurements of biomarkers of brain damage and activation of the coagulation system may potentially serve as nov......: This exploratory study indicated that blood levels of biomarkers GFAP and APC-PCI, prior to neuroimaging, may rule out ICH in a mixed stroke population.......INTRODUCTION: A simple and accurate method of differentiating ischemic stroke and intracerebral hemorrhage (ICH) is potentially useful to facilitate acute therapeutic management. Blood measurements of biomarkers of brain damage and activation of the coagulation system may potentially serve as novel...... diagnostic tools for stroke subtypes. METHODS: Ninety-seven stroke patients were prospectively investigated in a multicenter design with blood levels of brain biomarkers S100B, neuron specific enolase (NSE), glial fibrillary acidic protein (GFAP) as well as a coagulation biomarker, activated protein C...

  12. Effect of second language exposure on brain activity for language processing among preschoolers.

    Science.gov (United States)

    Hidaka, Souta; Shibata, Hiroshi; Kurihara, Michiyo; Tanaka, Akihiro; Konno, Akitsugu; Maruyama, Suguru; Gyoba, Jiro; Hagiwara, Hiroko; Koizumi, Masatoshi

    2012-05-01

    We investigated brain activity in 3-5-year-old preschoolers as they listened to connected speech stimuli in Japanese (first language), English (second language), and Chinese (a rarely exposed, foreign language) using near-infrared spectroscopy. Unlike the younger preschoolers who had been exposed to English for almost 1 year, brain activity in the bilateral frontal regions of the older preschoolers who had been exposed to English for almost 2 years was higher for Japanese and English speech stimuli than for Chinese. This tendency seemed to be similar to that observed in adults who had learned English for some years. These results indicate that exposure to a second language affects brain activity to language stimuli among preschoolers.

  13. Visualisation of multi-dimensional medical images with application to brain electrical impedance tomography

    OpenAIRE

    Zhang, Yan

    2007-01-01

    Medical imaging plays an important role in modem medicine. With the increasing complexity and information presented by medical images, visualisation is vital for medical research and clinical applications to interpret the information presented in these images. The aim of this research is to investigate improvements to medical image visualisation, particularly for multi-dimensional medical image datasets. A recently developed medical imaging technique known as Electrical Impedance Tomograp...

  14. Electro-dewatering of activated sludge: Electrical resistance analysis.

    Science.gov (United States)

    Conrardy, Jean-Baptiste; Vaxelaire, Jean; Olivier, Jérémy

    2016-09-01

    The significant risk of ohmic heating and the high electric energy consumption at terminal stages of the dewatering are two problems that hamper the development of the electro-dewatering (EDW) technology. In the future prospect of studying these two issues, it is important to provide and analyse quantitative data relative to the behavior of the electric resistance in EDW. It was the main goal of this study. It showed that the electric resistance of the complete system (cake + filter cloth) depended on the cake dryness. It increased sharply when the solids content exceeded around 45%.The solids loading also influenced the apparent resistance at the beginning of the process. The electric resistance of the filter cloth represented about 20% of the total resistance. It remained relatively constant over the process except at the terminal stage where it generally increased sharply. The use of conductive filter, such as metallic cloth, enabled to decrease the electric resistance and reduce the energy consumption of the process. The electric resistance decreased across the cake from the anode to the cathode. This behavior may be explained by several phenomena such as the ions migration and their interaction with the solid, the decrease of dry solids content from the anode to the cathode and the gas presence at the anode (due to electrolysis reaction). PMID:27192354

  15. Movement preparation and execution: differential functional activation patterns after traumatic brain injury.

    Science.gov (United States)

    Gooijers, Jolien; Beets, Iseult A M; Albouy, Genevieve; Beeckmans, Kurt; Michiels, Karla; Sunaert, Stefan; Swinnen, Stephan P

    2016-09-01

    Years following the insult, patients with traumatic brain injury often experience persistent motor control problems, including bimanual coordination deficits. Previous studies revealed that such deficits are related to brain structural white and grey matter abnormalities. Here, we assessed, for the first time, cerebral functional activation patterns during bimanual movement preparation and performance in patients with traumatic brain injury, using functional magnetic resonance imaging. Eighteen patients with moderate-to-severe traumatic brain injury (10 females; aged 26.3 years, standard deviation = 5.2; age range: 18.4-34.6 years) and 26 healthy young adults (15 females; aged 23.6 years, standard deviation = 3.8; age range: 19.5-33 years) performed a complex bimanual tracking task, divided into a preparation (2 s) and execution (9 s) phase, and executed either in the presence or absence of augmented visual feedback. Performance on the bimanual tracking task, expressed as the average target error, was impaired for patients as compared to controls (P brain injury patients showed enhanced activations compared with controls in frontal (left dorsolateral prefrontal cortex, left lateral anterior prefrontal cortex, and left orbitofrontal cortex), parietal (bilateral inferior parietal lobe, bilateral superior parietal lobe, right precuneus, right primary somatosensory cortex), occipital (right striate and extrastriate visual cortices), and subcortical (left cerebellum crus II) areas (P's brain injury (i.e. decreased neural differentiation). In sum, our findings point towards poorer predictive control in traumatic brain injury patients in comparison to controls. Moreover, irrespective of the feedback condition, overactivations were observed in traumatically brain injured patients during movement execution, pointing to more controlled processing of motor task performance.

  16. Contraction-induced muscle fiber damage is increased in soleus muscle of streptozotocin-diabetic rats and is associated with elevated expression of brain-derived neurotrophic factor mRNA in muscle fibers and activated satellite cells

    NARCIS (Netherlands)

    Copray, S; Liem, R; Brouwer, N; Greenhaff, P; Habens, F; Fernyhough, P

    2000-01-01

    The expression of brain-derived neurotrophic factor (BDNF) is elevated in the soleus muscle of streptozotocin-diabetic rats. To determine whether this diabetes-induced elevation was associated with or enhanced by muscle activity we have induced high-intensity muscle contraction by electrically stimu

  17. Is Brain Activity during Action Observation Modulated by the Perceived Fairness of the Actor?

    Directory of Open Access Journals (Sweden)

    Joset A Etzel

    Full Text Available 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 when experiencing similar emotions directly. This emotion perception associated activity has been shown to be affected by the perceived fairness of the actor, and in-group membership more generally. Here, we examine whether action observation associated brain activity is also affected by the perceived social fairness of the actors. Perceived fairness was manipulated using an alternating iterated Prisoner's Dilemma game between the participant and two confederates, one of whom played fairly and the other unfairly. During fMRI scanning the participants watched movies of the confederates performing object-directed hand actions, and then performed hand actions themselves. Mass-univariate analysis showed that observing the actions triggered robust activation in regions associated with action execution, but failed to identify a strong modulation of this activation based on perceived fairness. Multivariate pattern analysis, however, identified clusters potentially carrying information about the perceived fairness of the actor in the middle temporal gyrus, left postcentral gyrus, right inferior parietal lobule, right middle cingulate cortex, right angular gyrus, and right superioroccipital gyrus. Despite being identified by a whole-brain searchlight analysis (and so without anatomical restriction, these clusters fall into areas frequently associated with action observation. We conclude that brain activity during action observation may be modulated by perceived fairness, but such modulation is subtle; robust activity is associated with observing the actions of both fair and unfair individuals.

  18. Is Brain Activity during Action Observation Modulated by the Perceived Fairness of the Actor?

    Science.gov (United States)

    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 when experiencing similar emotions directly. This emotion perception associated activity has been shown to be affected by the perceived fairness of the actor, and in-group membership more generally. Here, we examine whether action observation associated brain activity is also affected by the perceived social fairness of the actors. Perceived fairness was manipulated using an alternating iterated Prisoner's Dilemma game between the participant and two confederates, one of whom played fairly and the other unfairly. During fMRI scanning the participants watched movies of the confederates performing object-directed hand actions, and then performed hand actions themselves. Mass-univariate analysis showed that observing the actions triggered robust activation in regions associated with action execution, but failed to identify a strong modulation of this activation based on perceived fairness. Multivariate pattern analysis, however, identified clusters potentially carrying information about the perceived fairness of the actor in the middle temporal gyrus, left postcentral gyrus, right inferior parietal lobule, right middle cingulate cortex, right angular gyrus, and right superioroccipital gyrus. Despite being identified by a whole-brain searchlight analysis (and so without anatomical restriction), these clusters fall into areas frequently associated with action observation. We conclude that brain activity during action observation may be modulated by perceived fairness, but such modulation is subtle; robust activity is associated with observing the actions of both fair and unfair individuals. PMID:26820995

  19. Mescaline-induced changes of brain-cortex ribosomes. Mescaline demethylase activity of brain-cortex soluble supernatant.

    Science.gov (United States)

    Datta, R K; Ghosh, J J

    1977-02-01

    Brain-cortex slices demethylate mescaline and p-methoxyacetanilide, a reference O-demethylating substrate, though the rate of demethylation of mescaline is about one third that of the reference substrate. The demethylase activity is localized mostly in the soluble supernatant (105 000 x g). It is purified 47-fold with respect to the demethylation of mescaline by ammonium sulfate precipitation and DEAE cellulose chromatography. The partially purified demethylase, which is stable for 3-5 days at -5 degrees C in the presence of dithiothreitol and glutathione and is inhibited by p-chloromercuribenzoate, has maximal activity at pH between 7.2 and 8.0. It demethylates mescaline into 3,4-dimethoxy-5-hydroxyphenethylamine and 3,5-dimethoxy-4-hydroxyphenethylamine and some unidentified derivatives.

  20. Hierarchical brain networks active in approach and avoidance goal pursuit

    Directory of Open Access Journals (Sweden)

    Jeffrey Martin Spielberg

    2013-06-01

    Full Text Available Effective approach/avoidance goal pursuit is critical for attaining long-term health and well-being. Research on the neural correlates of key goal pursuit processes (e.g., motivation has long been of interest, with lateralization in prefrontal cortex being a particularly fruitful target of investigation. However, this literature has often been limited by a lack of spatial specificity and has not delineated the precise aspects of approach/avoidance motivation involved. Additionally, the relationships among brain regions (i.e., network connectivity vital to goal pursuit remain largely unexplored. Specificity in location, process, and network relationship is vital for moving beyond gross characterizations of function and identifying the precise cortical mechanisms involved in motivation. The present paper integrates research using more spatially specific methodologies (e.g., functional magnetic resonance imaging with the rich psychological literature on approach/avoidance to propose an integrative network model that takes advantage of the strengths of each of these literatures.

  1. Secondary Activation of Commercial Activated Carbon and its Application in Electric Double Layer Capacitor

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The cheap commercial activated carbon (AC) was improved through the secondary activation under steam in the presence of FeCl2 catalyst in the temperature range of 800-950℃ and its application in electric double layer capacitors (EDLCs) with organic electrolyte was studied. The re-activation of AC results in the increases in both specific capacitance and high rate capability of EDLCs. For AC treated under optimized conditions, its discharge specific capacitance increases up to 55.65 F/g, an increase of about 33% as compared to the original AC, and the high rate capability was increased significantly. The good performances of EDLC with improved AC were correlated to the increasing mesoporous ratio.

  2. Brain activity in advantageous and disadvantageous situations: implications for reward/punishment sensitivity in different situations.

    Directory of Open Access Journals (Sweden)

    Guangheng Dong

    Full Text Available OBJECTIVE: This study modeled win and lose trials in a simple gambling task to examine the effect of entire win-lose situations (WIN, LOSS, or TIE on single win/lose trials and related neural underpinnings. METHODS: The behavior responses and brain activities of 17 participants were recorded by an MRI scanner while they performed a gambling task. Different conditions were compared to determine the effect of the task on the behavior and brain activity of the participants. Correlations between brain activity and behavior were calculated to support the imaging results. RESULTS: In win trials, LOSS caused less intense posterior cingulate activity than TIE. In lose trials, LOSS caused more intense activity in the right superior temporal gyrus, bilateral superior frontal gyrus, bilateral anterior cingulate, bilateral insula cortex, and left orbitofrontal cortex than WIN and TIE. CONCLUSIONS: The experiences of the participants in win trials showed great similarity among different win-lose situations. However, the brain activity and behavior responses of the participants in lose trials indicated that they experienced stronger negative emotion in LOSS. The participants also showed an increased desire to win in LOSS than in WIN or TIE conditions.

  3. Watching TV news as a memory task -- brain activation and age effects

    Directory of Open Access Journals (Sweden)

    Frings Lars

    2010-08-01

    Full Text Available Abstract Background Neuroimaging studies which investigate brain activity underlying declarative memory processes typically use artificial, unimodal laboratory stimuli. In contrast, we developed a paradigm which much more closely approximates real-life situations of information encoding. Methods In this study, we tested whether ecologically valid stimuli - clips of a TV news show - are apt to assess memory-related fMRI activation in healthy participants across a wide age range (22-70 years. We contrasted brain responses during natural stimulation (TV news video clips with a control condition (scrambled versions of the same clips with reversed audio tracks. After scanning, free recall performance was assessed. Results The memory task evoked robust activation of a left-lateralized network, including primarily lateral temporal cortex, frontal cortex, as well as the left hippocampus. Further analyses revealed that - when controlling for performance effects - older age was associated with greater activation of left temporal and right frontal cortex. Conclusion We demonstrate the feasibility of assessing brain activity underlying declarative memory using a natural stimulation paradigm with high ecological validity. The preliminary result of greater brain activation with increasing age might reflect an attempt to compensate for decreasing episodic memory capacity associated with aging.

  4. The time-course and spatial distribution of brain activity associated with sentence processing.

    Science.gov (United States)

    Brennan, Jonathan; Pylkkänen, Liina

    2012-04-01

    Sentence comprehension involves a host of highly interrelated processes, including syntactic parsing, semantic composition, and pragmatic inferencing. In neuroimaging, a primary paradigm for examining the brain bases of sentence processing has been to compare brain activity elicited by sentences versus unstructured lists of words. These studies commonly find an effect of increased activity for sentences in the anterior temporal lobes (aTL). Together with neuropsychological data, these findings have motivated the hypothesis that the aTL is engaged in sentence level combinatorics. Combinatoric processing during language comprehension, however, occurs within tens and hundreds of milliseconds, i.e., at a time-scale much faster than the temporal resolution of hemodynamic measures. Here, we examined the time-course of sentence-level processing using magnetoencephalography (MEG) to better understand the temporal profile of activation in this common paradigm and to test a key prediction of the combinatoric hypothesis: because sentences are interpreted incrementally, word-by-word, activity associated with basic linguistic combinatorics should be time-locked to word-presentation. Our results reveal increased anterior temporal activity for sentences compared to word lists beginning approximately 250 ms after word onset. We also observed increased activation in a network of other brain areas, extending across posterior temporal, inferior frontal, and ventral medial areas. These findings confirm a key prediction of the combinatoric hypothesis for the aTL and further elucidate the spatio-temporal characteristics of sentence-level computations in the brain.

  5. Modulation of IκB kinase autophosphorylation and activity following brain ischemia

    Institute of Scientific and Technical Information of China (English)

    SHENWan-Hua; ZHANGHun-Yi; 等

    2003-01-01

    ATIM:To investigate the effects of different antagonists on the alteration of IκB kinase(IKK)activity in rat hipoocampus folluwing global brain ischemia,METHODS:Using 4-vessel occlusion(4-VO)as brain ischemia model,IKK protein expression was examined by immunoblotting and immunoprecipitation,and IKK activity was assayed by in vitro kinase assay.RESULTS:There was no alteration of IKK protein expression following ischemia or ischemia/reperfusion different time points,but IKK activity reached its peak level at ischemia 30min.Pretreatment with N-methyl-D-aspartate(NMDA)receptor antagonist ketamine,non-NMDA receptor antagonist DNQX,or NFκB inhibitor PDTC decreased the IKK activity following brain ischemia 30min.The increase in substrate myelin basic protein(MBP)phosphorylation by IKK is associated with an increase in autophosphorylation of IKK,which can also be antagonized by ketamine,DNQX,and PDTC,CONCLUSION:NMDA receptor and non-NMDA receptor mediate the increase of IKK activity following global brain ischemia in rat hippocampus,which contributes to the alterations of expression and activity of downstream factor NF-κB.

  6. Regional Brain Activation during Meditation Shows Time and Practice Effects: An Exploratory FMRI Study

    Directory of Open Access Journals (Sweden)

    E. Baron Short

    2010-01-01

    Full Text Available Meditation involves attentional regulation and may lead to increased activity in brain regions associated with attention such as dorsal lateral prefrontal cortex (DLPFC and anterior cingulate cortex (ACC. Using functional magnetic resonance imaging, we examined whether DLPFC and ACC were activated during meditation. Subjects who meditate were recruited and scanned on a 3.0 Tesla scanner. Subjects meditated for four sessions of 12 min and performed four sessions of a 6 min control task. Individual and group t-maps were generated of overall meditation response versus control response and late meditation response versus early meditation response for each subject and time courses were plotted. For the overall group (n = 13, and using an overall brain analysis, there were no statistically significant regional activations of interest using conservative thresholds. A region of interest analysis of the entire group time courses of DLPFC and ACC were statistically more active throughout meditation in comparison to the control task. Moreover, dividing the cohort into short (n = 8 and long-term (n = 5 practitioners (>10 years revealed that the time courses of long-term practitioners had significantly more consistent and sustained activation in the DLPFC and the ACC during meditation versus control in comparison to short-term practitioners. The regional brain activations in the more practised subjects may correlate with better sustained attention and attentional error monitoring. In summary, brain regions associated with attention vary over the time of a meditation session and may differ between long- and short-term meditation practitioners.

  7. NOX Activity in Brain Aging: Exacerbation by High Fat Diet

    OpenAIRE

    Bruce-Keller, Annadora J.; White, Christy L.; Gupta, Sunita; Knight, Alecia G.; Pistell, Paul J.; Ingram, Donald K.; Morrison, Christopher D.; Keller, Jeffrey N.

    2010-01-01

    This study describes how age and high fat diet affect the profile of NADPH oxidase (NOX). Specifically, NOX activity and subunit expression were evaluated in the frontal cerebral cortex of 7-, 16-, and 24-month old mice following a 4-month exposure to either Western diet (WD, 41% calories from fat) or very high fat lard diet (VHFD, 60% calories from fat). Data reveal a significant effect of age in on NOX activity, and show that NOX activity was only increased by VHFD, and only in 24-month old...

  8. Brain-Activity-Driven Real-Time Music Emotive Control

    OpenAIRE

    Giraldo, Sergio; Ramirez, Rafael

    2013-01-01

    Active music listening has emerged as a study field that aims to enable listeners to interactively control music. Most of active music listening systems aim to control music aspects such as playback, equalization, browsing, and retrieval, but few of them aim to control expressive aspects of music to convey emotions. In this study our aim is to enrich the music listening experience by allowing listeners to control expressive parameters in music performances using their perceived emotional stat...

  9. Brain's reward circuits mediate itch relief. a functional MRI study of active scratching.

    Directory of Open Access Journals (Sweden)

    Alexandru D P Papoiu

    Full Text Available Previous brain imaging studies investigating the brain processing of scratching used an exogenous intervention mimicking scratching, performed not by the subjects themselves, but delivered by an investigator. In real life, scratching is a conscious, voluntary, controlled motor response to itching, which is directed to the perceived site of distress. In this study we aimed to visualize in real-time by brain imaging the core mechanisms of the itch-scratch cycle when scratching was performed by subjects themselves. Secondly, we aimed to assess the correlations between brain patterns of activation and psychophysical ratings of itch relief or pleasurability of scratching. We also compared the patterns of brain activity evoked by self-scratching vs. passive scratching. We used a robust tridimensional Arterial Spin Labeling fMRI technique that is less sensitive to motion artifacts: 3D gradient echo and spin echo (GRASE--Propeller. Active scratching was accompanied by a higher pleasurability and induced a more pronounced deactivation of the anterior cingulate cortex and insula, in comparison with passive scratching. A significant involvement of the reward system including the ventral tegmentum of the midbrain, coupled with a mechanism deactivating the periaqueductal gray matter (PAG, suggests that itch modulation operates in reverse to the mechanism known to suppress pain. Our findings not only confirm a role for the central networks processing reward in the pleasurable aspects of scratching, but also suggest they play a role in mediating itch relief.

  10. Brain activity in predictive sensorimotor control for landings: an EEG pilot study.

    Science.gov (United States)

    Baumeister, J; von Detten, S; van Niekerk, S-M; Schubert, M; Ageberg, E; Louw, Q A

    2013-12-01

    Landing from a jump is related to predictive sensorimotor control. Frontal, central and parietal brain areas are known to play a role in this process based on online sensory feedback. This can be measured by EEG. However, there is only limited knowledge about brain activity during predictive preparation for drop landings (DL). The purpose is to demonstrate changes in brain activity in preparation for DL in different conditions. After resting, 10 athletes performed a series of DLs and were asked to concentrate on the landing preparation for 10 s before an auditory signal required them to drop land from a 30 cm platform. This task was executed before and after a standardized fatigue protocol. EEG spectral power was calculated during DL preparation. Frontal Theta power was increased during preparation compared to rest. Parietal Alpha-2 power demonstrated higher values in preparation after fatigue condition while lower limb kinematics remained unchanged. Cortical activity in frontal and parietal brain areas is sensitive for predictive sensorimotor control of drop landings. Frontal Theta power demonstrates an increase and is related to higher attentional control. In a fatigued condition the parietal Alpha-2 power increase might be related to a deactivation in the somatosensory brain areas. PMID:23740338

  11. Decoding the Semantic Content of Natural Movies from Human Brain Activity

    Science.gov (United States)

    Huth, Alexander G.; Lee, Tyler; Nishimoto, Shinji; Bilenko, Natalia Y.; Vu, An T.; Gallant, Jack L.

    2016-01-01

    One crucial test for any quantitative model of the brain is to show that the model can be used to accurately decode information from evoked brain activity. Several recent neuroimaging studies have decoded the structure or semantic content of static visual images from human brain activity. Here we present a decoding algorithm that makes it possible to decode detailed information about the object and action categories present in natural movies from human brain activity signals measured by functional MRI. Decoding is accomplished using a hierarchical logistic regression (HLR) model that is based on labels that were manually assigned from the WordNet semantic taxonomy. This model makes it possible to simultaneously decode information about both specific and general categories, while respecting the relationships between them. Our results show that we can decode the presence of many object and action categories from averaged blood-oxygen level-dependent (BOLD) responses with a high degree of accuracy (area under the ROC curve > 0.9). Furthermore, we used this framework to test whether semantic relationships defined in the WordNet taxonomy are represented the same way in the human brain. This analysis showed that hierarchical relationships between general categories and atypical examples, such as organism and plant, did not seem to be reflected in representations measured by BOLD fMRI. PMID:27781035

  12. Brain activity modification produced by a single radioelectric asymmetric brain stimulation pulse: a new tool for neuropsychiatric treatments. Preliminary fMRI study

    Directory of Open Access Journals (Sweden)

    Castagna A

    2011-10-01

    Full Text Available Salvatore Rinaldi1,2, Vania Fontani1, Alessandro Castagna1 1Department of Neuro-Psycho-Physio Pathology, Rinaldi Fontani Institute, Florence, Italy; 2Medical School of Occupational Medicine, University of Florence, Florence, Italy Purpose: Radioelectric asymmetric brain stimulation technology with its treatment protocols has shown efficacy in various psychiatric disorders. The aim of this work was to highlight the mechanisms by which these positive effects are achieved. The current study was conducted to determine whether a single 500-millisecond radioelectric asymmetric conveyor (REAC brain stimulation pulse (BSP, applied to the ear, can effect a modification of brain activity that is detectable using functional magnetic resonance imaging (fMRI. Methods: Ten healthy volunteers, six females and four males, underwent fMRI during a simple finger-tapping motor task before and after receiving a single 500-millisecond REAC-BSP. Results: The fMRI results indicate that the average variation in task-induced encephalic activation patterns is lower in subjects following the single REAC pulse. Conclusion: The current report demonstrates that a single REAC-BSP is sufficient to modulate brain activity in awake subjects, able to be measured using fMRI. These initial results open new perspectives into the understanding of the effects of weak and brief radio pulses upon brain activity, and provide the basis for further indepth studies using REAC-BSP and fMRI. Keywords: fMRI, brain stimulation, brain modulation, REAC, neuropsychiatric treatments

  13. Differential Brain Activation in Anorexia Nervosa to Fat and Thin Words During a Stroop Task

    OpenAIRE

    Redgrave, Graham W.; Bakker, Arnold; Nicholas T Bello; Caffo, Brian S.; Coughlin, Janelle W.; Guarda, Angela S.; McEntee, Julie E.; Pekar, James J.; Reinblatt, Shauna P; Verduzco, Guillermo; Moran, Timothy H.

    2008-01-01

    We measured brain activation in six anorexia nervosa patients and six healthy controls performing a novel emotional Stroop task using Fat, Thin, and Neutral words, and words made of XXXXs. Reaction times increased in the patient group in Thin and Fat conditions. In the Thin-XXXX contrast, patients showed greater activation than controls at the junction of left insula, frontal and temporal lobes and in left middle and medial frontal gyri. In the Fat-XXXX contrast, controls showed greater activ...

  14. Clinical studies of brain functional images by motor activation using single photon emission computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Kawaguchi, Masahiro [Gifu Univ. (Japan). School of Medicine

    1998-09-01

    Thirty participants (10 normal controls; group A, 5 patients with brain tumors located near central sulcus without hemiparesis; group B, 10 patients with brain tumors located near central sulcus with hemiparesis; group C, and 5 patients with brain tumors besides the central regions with hemiparesis; group D) were enrolled. The images were performed by means of split-dose method with {sup 99m}Tc-ECD at rest condition (SPECT 1) and during hand grasping (SPECT 2). The activation SPECT were obtained by subtracting SPECT 1 from SPECT 2, and the functional mapping was made by the strict registration of the activation SPECT with 3D MRI. To evaluate the changes of CBF (%{Delta}CBF) of the sensorimotor and supplementary motor areas on the functional mapping, ratio of the average counts of SPECT 1 and SPECT 2 was calculated and statistically compared. The functional activation paradigms caused a significant increase of CBF in the sensorimotor area contra-lateral to the stimulated hand, although the sensorimotor area and the central sulcus in groups B and C were dislocated, compared with hemisphere of non-tumor side. The sensorimotor area ipsi-lateral to the stimulated hand could be detected in almost of all subjects. The supplementary motor area could be detected in all subjects. In group A, the average %{Delta}CBF were up 24.1{+-}4.3% in the contra-lateral sensorimotor area, and 22.3{+-}3.6% in the supplementary motor area, respectively. The average %{Delta}CBF in the contra-lateral sensorimotor area of group D was significantly higher than that of group A. The brain functional mapping by motor activation using SPECT could localize the area of cortical motor function in normal volunteers and patients with brain tumors. The changes of regional CBF by activation SPECT precisely assess the cortical motor function even in patients with brain tumors located near central sulcus. (K.H.)

  15. Comparison of two treatments for coxarthrosis: local hyperthermia versus radio electric asymmetrical brain stimulation

    Directory of Open Access Journals (Sweden)

    Castagna A

    2011-07-01

    Full Text Available Alessandro Castagna1, Salvatore Rinaldi1,2, Vania Fontani1, Piero Mannu1, Matteo Lotti Margotti11Rinaldi Fontani Institute, Department of Neuro Psycho Physio Pathology, 2Medical School of Occupational Medicine, University of Florence, Florence, ItalyBackground: It is well known that psychological components are very important in the aging process and may also manifest in psychogenic movement disorders, such as coxarthrosis. This study analyzed the medical records of two similar groups of patients with coxarthrosis (n = 15 in each who were treated in two different clinics for rehabilitation therapy.Methods: Patients in Group A were treated with a course of traditional physiotherapy, including sessions of local hyperthermia. Group B patients were treated with only a course of radioelectric asymmetrical brain stimulation (REAC to improve their motor behavior.Results: Group A showed a significant decrease in symptoms of pain and stiffness, and an insignificant improvement in range of motion and muscle bulk. A single patient in this group developed worsened symptoms, and pain did not resolve completely in any patient. The patients in Group B had significantly decreased levels of pain and stiffness, and a significant improvement in range of motion and muscle bulk. No patients worsened in Group B, and the pain resolved completely in one patient.Conclusion: Both treatments were shown to be tolerable and safe. Patients who underwent REAC treatment appeared to have slightly better outcomes, with an appreciable improvement in both their physical and mental states. These aspects are particularly important in the elderly, in whom functional limitation is often associated with or exacerbated by a psychogenic component.Keywords: coxarthrosis, anti-aging, motor behavior, radioelectric asymmetric brain stimulation

  16. Rapid eye movement sleep deprivation induces an increase in acetylcholinesterase activity in discrete rat brain regions

    Directory of Open Access Journals (Sweden)

    Benedito M.A.C.

    2001-01-01

    Full Text Available Some upper brainstem cholinergic neurons (pedunculopontine and laterodorsal tegmental nuclei are involved in the generation of rapid eye movement (REM sleep and project rostrally to the thalamus and caudally to the medulla oblongata. A previous report showed that 96 h of REM sleep deprivation in rats induced an increase in the activity of brainstem acetylcholinesterase (Achase, the enzyme which inactivates acetylcholine (Ach in the synaptic cleft. There was no change in the enzyme's activity in the whole brain and cerebrum. The components of the cholinergic synaptic endings (for example, Achase are not uniformly distributed throughout the discrete regions of the brain. In order to detect possible regional changes we measured Achase activity in several discrete rat brain regions (medulla oblongata, pons, thalamus, striatum, hippocampus and cerebral cortex after 96 h of REM sleep deprivation. Naive adult male Wistar rats were deprived of REM sleep using the flower-pot technique, while control rats were left in their home cages. Total, membrane-bound and soluble Achase activities (nmol of thiocholine formed min-1 mg protein-1 were assayed photometrically. The results (mean ± SD obtained showed a statistically significant (Student t-test increase in total Achase activity in the pons (control: 147.8 ± 12.8, REM sleep-deprived: 169.3 ± 17.4, N = 6 for both groups, P<0.025 and thalamus (control: 167.4 ± 29.0, REM sleep-deprived: 191.9 ± 15.4, N = 6 for both groups, P<0.05. Increases in membrane-bound Achase activity in the pons (control: 171.0 ± 14.7, REM sleep-deprived: 189.5 ± 19.5, N = 6 for both groups, P<0.05 and soluble enzyme activity in the medulla oblongata (control: 147.6 ± 16.3, REM sleep-deprived: 163.8 ± 8.3, N = 6 for both groups, P<0.05 were also observed. There were no statistically significant differences in the enzyme's activity in the other brain regions assayed. The present findings show that the increase in Achase activity

  17. Antecedents of employee electricity saving behavior in organizations: An empirical study based on norm activation model

    International Nuclear Information System (INIS)

    China is one of the major energy-consuming countries, and is under great pressure to promote energy saving and reduce domestic energy consumption. Employees constitute an important target group for energy saving. However, only a few research efforts have been paid to study what drives employee energy saving behavior in organizations. To fill this gap, drawing on norm activation model (NAM), we built a research model to study antecedents of employee electricity saving behavior in organizations. The model was empirically tested using survey data collected from office workers in Beijing, China. Results show that personal norm positively influences employee electricity saving behavior. Organizational electricity saving climate negatively moderates the effect of personal norm on electricity saving behavior. Awareness of consequences, ascription of responsibility, and organizational electricity saving climate positively influence personal norm. Furthermore, awareness of consequences positively influences ascription of responsibility. This paper contributes to the energy saving behavior literature by building a theoretical model of employee electricity saving behavior which is understudied in the current literature. Based on the empirical results, implications on how to promote employee electricity saving are discussed. - Highlights: • We studied employee electricity saving behavior based on norm activation model. • The model was tested using survey data collected from office workers in China. • Personal norm positively influences employee′s electricity saving behavior. • Electricity saving climate negatively moderates personal norm′s effect. • This research enhances our understanding of employee electricity saving behavior

  18. Effects of weak electric fields on the activity of neurons and neuronal networks

    Energy Technology Data Exchange (ETDEWEB)

    Jeffreys, J.G.R.; Deans, J.; Bikson, M.; Fox, J

    2003-07-01

    Electric fields applied to brain tissue will affect cellular properties. They will hyperpolarise the ends of cells closest to the positive part of the field, and depolarise ends closest to the negative. In the case of neurons this affects excitability. How these changes in transmembrane potential are distributed depends on the length constant of the neuron, and on its geometry; if the neuron is electrically compact, the change in transmembrane potential becomes an almost linear function of distance in the direction of the field. Neurons from the mammalian hippocampus, maintained in tissue slices in vitro, are significantly affected by fields of around 1-5 Vm{sup -1}. (author)

  19. Low-frequency electrical stimulation improves neurite outgrowth of dorsal root ganglion neurons in vitro via upregulating Ca2+-mediated brain-derived neurotrophic factor expression

    Institute of Scientific and Technical Information of China (English)

    Lidan Wan; Rong Xia; Wenlong Ding

    2010-01-01

    Short-term,low-frequency electrical stimulation of neural tissues significantly enhances axonal regeneration of peripheral nerves following injury.However,little is known about the mechanisms of electrical stimulation to induce neurite outgrowth.In the present study,short-term,low-frequency electrical stimulation,using identical stimulation parameters of in vivo experiments,was administered to in vitro dorsal root ganglion(DRG)neurons.Enhanced neurite outgrowth,as well as synthesis and release of brain-derived neurotrophic factor(BDNF),were examined in electrical stimulation-treated DRG neuronal cultures.Because the effects of electrical stimulation on neuronal intracellular signaling molecules are less reported,classic calcium intracellular signals are directly or indirectly involved in electrical stimulation effects on neurons.Cultured DRG neurons were pretreated with the calcium channel blocker nifedipine,followed by electrical stimulation.Results suggested that electrical stimulation not only promoted in vitro neurite outgrowth,but also enhanced BDNF expression.However,nifedipine reduced electrical stimulation-enhanced neurite outgrowth and BDNF biosynthesis.These results suggest that the promoting effects of electrical stimulation on DRG neurite outgrowth could be associated with altered calcium influx,which is involved induction of neuronal BDNF expression and secretion.

  20. Distribution of phosphorylated Elk-1 in rat brain after Y-maze active avoidance training in a temporal manner

    Institute of Scientific and Technical Information of China (English)

    Xuhong Chen; Siyun Shu; Zhenjiang Liang; Xinmin Bao; Lixue Chen; Yongming Wu

    2006-01-01

    BACKGROUND: Elk-1 mRNA distributes extensively in the neurons of mice, rat and human brains, and the Elk-1 expression may be correlated with the synaptic plasticity, learning and memory.OBJECTIVE: To observe the distribution of phosphorylated Elk-1 (pElk-1) in whole brain of rats received Y-maze active avoidance training and the changes of pElk-1 expression at different time points after training.DESIGN: A randomized controlled study.SETTING: Research Room of Neurobiology, the Second Affiliated Hospital of Southern Medical University.MATERIALS: Fifty-five male clean-degree SD rats of 3-4 months old, weighing 200-250 g, were provided by the Experimental Animal Center of Southern Medical University. The rabbit anti-monoclonal pElk-1 antibody was purchased from Cell Signal Transduction Company, and ABC kit from Vector Company.METHODS: The experiments were carried out in the Research Room of Neurobiology, Second Affiliated Hospital of Southern Medical University from September 2004 to February 2005. ① Grouping: The rats were randomly divided into training group (n = 25), sham-training group (n = 25) and norm al control group (n = 5), and the training and sham-training groups were observed at 0, 1, 3, 6 and 24 hours after training, which represented the five phases in the process of learning and memory. ② Y-maze training: The rats were preconditioned in the electrical Y-maze apparatus, 20 minutes a day for 3 days continuously, and training began from the 4th day. In the training group, the rats were trained with the combination of light and electricity. Each rat repeated for 60 times in each training, and the correct times were recorded, those correct for less than 25 times were taken as unqualified, and excluded from the training group, and supplemented by other rats in time. In the sham-training group, there was no fixed correlation between the application of light and electricity. The rats in the normal control group were given not any training. ③Detection of p

  1. Brain activation during phonological and semantic processing of Chinese characters in deaf signers

    Science.gov (United States)

    Li, Yanyan; Peng, Danling; Liu, Li; Booth, James R.; Ding, Guosheng

    2014-01-01

    Previous studies found altered brain function in deaf individuals reading alphabetic orthographies. However, it is not known whether similar alterations of brain function are characteristic of non-alphabetic writing systems and whether alterations are specific to certain kinds of lexical tasks. Here we examined differences in brain activation between Chinese congenitally deaf individuals (CD) and hearing controls (HC) during character reading tasks requiring phonological and semantic judgments. For both tasks, we found that CD showed less activation than HC in left inferior frontal gyrus, but greater activation in several right hemisphere regions including inferior frontal gyrus, angular gyrus, and inferior temporal gyrus. Although many group differences were similar across tasks, greater activation in right middle frontal gyrus was more pronounced for the rhyming compared to the meaning task. Finally, within the deaf individuals better performance on the rhyming task was associated with less activation in right inferior parietal lobule and angular gyrus. Our results in Chinese CD are broadly consistent with previous studies in alphabetic languages suggesting greater engagement of inferior frontal gyrus and inferior parietal cortex for reading that is largely independent of task, with the exception of right middle frontal gyrus for phonological processing. The brain behavior correlations potentially indicate that CD that more efficiently use the right hemisphere are better readers. PMID:24795593

  2. Comparison of Brain Activation in Response to Two Dimensional and Three Dimensional On-Line Games

    Science.gov (United States)

    Song, Woo Hyun; Shim, Hyung Jin

    2013-01-01

    Objective The present study assessed the difference in the brain activity of professional gamers (excessive players, but not addicts) in response to playing a 3-dimensional online game with an improved interface. Methods Twenty-three StarCraft I pro gamers and 16 StarCraft II pro gamers were recruited at Chung Ang University Medical Center. Brain activity in response to StarCraft I or II cues was assessed with a 1.5 Tesla Espree MRI scanner. Results StarCraft I pro gamers showed significantly greater activity in 4 clusters in response to the video game cues compared to StarCraft II pro gamers: right superior frontal gyrus, right medial frontal gyrus, right occipital lobe, and left medial frontal gyrus. StarCraft II pro gamers showed significantly greater activity in 3 clusters in response to the video game cues compared to StarCraft I pro gamers: left middle frontal gyrus, left temporal fusiform gyrus and left cerebellum. Discussion This is the first study to show the difference in brain activity between gamers playing either a 2-dimensional or 3-dimensional online game. Current brain imaging studies may confirm the pro gamers' experience when playing StarCraft II, a 3-dimensional game with an improved interface, relative to playing StarCraft I. PMID:23798958

  3. Human high intelligence is involved in spectral redshift of biophotonic activities in the brain

    Science.gov (United States)

    Wang, Niting; Li, Zehua; Xiao, Fangyan; Dai, Jiapei

    2016-01-01

    Human beings hold higher intelligence than other animals on Earth; however, it is still unclear which brain properties might explain the underlying mechanisms. The brain is a major energy-consuming organ compared with other organs. Neural signal communications and information processing in neural circuits play an important role in the realization of various neural functions, whereas improvement in cognitive function is driven by the need for more effective communication that requires less energy. Combining the ultraweak biophoton imaging system (UBIS) with the biophoton spectral analysis device (BSAD), we found that glutamate-induced biophotonic activities and transmission in the brain, which has recently been demonstrated as a novel neural signal communication mechanism, present a spectral redshift from animals (in order of bullfrog, mouse, chicken, pig, and monkey) to humans, even up to a near-infrared wavelength (∼865 nm) in the human brain. This brain property may be a key biophysical basis for explaining high intelligence in humans because biophoton spectral redshift could be a more economical and effective measure of biophotonic signal communications and information processing in the human brain. PMID:27432962

  4. Brain activity and cognition: a connection from thermodynamics and information theory.

    Science.gov (United States)

    Collell, Guillem; Fauquet, Jordi

    2015-01-01

    The connection between brain and mind is an important scientific and philosophical question that we are still far from completely understanding. A crucial point to our work is noticing that thermodynamics provides a convenient framework to model brain activity, whereas cognition can be modeled in information-theoretical terms. In fact, several models have been proposed so far from both approaches. A second critical remark is the existence of deep theoretical connections between thermodynamics and information theory. In fact, some well-known authors claim that the laws of thermodynamics are nothing but principles in information theory. Unlike in physics or chemistry, a formalization of the relationship between information and energy is currently lacking in neuroscience. In this paper we propose a framework to connect physical brain and cognitive models by means of the theoretical connections between information theory and thermodynamics. Ultimately, this article aims at providing further insight on the formal relationship between cognition and neural activity.

  5. Optical activity of microemulsion induced by electric field and its tunable behaviors

    Institute of Scientific and Technical Information of China (English)

    ZHAO; Xiaopeng(赵晓鹏); ZHAO; Qian(赵乾); XIANG; Liqin(向礼琴)

    2003-01-01

    It has been shown that optical activity can occur in microemulsion under external electric field and rotation angle can also be tuned by the electric field. A set of microemulsions (water/Span80/transformer oil) with different water concentration were prepared and their optical activity was measured with the changes of applied electric field and θ, the angle between the electric vector of the incident linearly polarized light and the external electric field, using an automatic polarimeter. The experiments indicate that when none of the external electric field, water concentration and θ are zero, there is optical activity in microemulsions. For a given concentration, rotation angle ψ increases with electric field, and it firstly increases, passes through a maximum at C = C0,then monotonically decreases as C increases when electric field keeps constant. The relationship between the rotation angle and θ is also obtained. It is thought that the electric field-induced destroy of spatial symmetry of microemulsion is responsible for the optical activity of microemulsion.

  6. Brain in Space: A Teacher's Guide with Activities for Neuroscience

    Science.gov (United States)

    Sullivan, Walter W., Jr.

    1998-01-01

    The lessons and activities in this guide will engage your students in the excitement of space life science investigations after the Neurolab Spacelab mission. It is the authors' goal that the information in this guide will inspire both you and your students to become interested and active participants in this space mission. Few experiences can compare with the excitement and thrill of watching a Shuttle launch. This guide provides an opportunity for you and your students to go one step further by conducting the experiments on Earth that are relevent to the research conducted in space.

  7. Bovine growth hormone transgenic mice display alterations in locomotor activity and brain monoamine neurochemistry.

    Science.gov (United States)

    Söderpalm, B; Ericson, M; Bohlooly, M; Engel, J A; Törnell, J

    1999-12-01

    Recent clinical and experimental data indicate a role for GH in mechanisms related to anhedonia/hedonia, psychic energy, and reward. In the present study we have investigated whether bovine GH (bGH) transgenic mice and nontransgenic controls differ in spontaneous locomotor activity, a behavioral response related to brain dopamine (DA) and reward mechanisms, as well as in locomotor activity response to drugs of abuse known to interfere with brain DA systems. The animals were tested for locomotor activity once a week for 4 weeks. When first exposed to the test apparatus, bGH transgenic animals displayed significantly more locomotor activity than controls during the entire registration period (1 h). One week later, after acute pretreatment with saline, the two groups did not differ in locomotor activity, whereas at the third test occasion, bGH mice were significantly more stimulated by d-amphetamine (1 mg/kg, ip) than controls. At the fourth test, a tendency for a larger locomotor stimulatory effect of ethanol (2.5 g/kg, ip) was observed in bGH transgenic mice. bGH mice displayed increased tissue levels of serotonin and 5-hydroxyindoleacetic acid in several brain regions, decreased DA levels in the brain stem, and decreased levels of the DA metabolite 3,4-dihydroxyphenylacetic acid in the mesencephalon and diencephalon, compared with controls. In conclusion, bGH mice display more spontaneous locomotor activity than nontransgenic controls in a novel environment and possibly also a disturbed habituation process. The finding that bGH mice were also more sensitive to d-amphetamine-induced locomotor activity may suggest that the behavioral differences observed are related to differences in brain DA systems, indicating a hyperresponsiveness of these systems in bGH transgenic mice. These findings may constitute a neurochemical basis for the reported psychic effects of GH in humans. PMID:10579325

  8. Altered sensorimotor activation patterns in idiopathic dystonia-an activation likelihood estimation meta-analysis of functional brain imaging studies

    DEFF Research Database (Denmark)

    Løkkegaard, Annemette; Herz, Damian M; Haagensen, Brian N;

    2016-01-01

    Dystonia is characterized by sustained or intermittent muscle contractions causing abnormal, often repetitive, movements or postures. Functional neuroimaging studies have yielded abnormal task-related sensorimotor activation in dystonia, but the results appear to be rather variable across studies....... Hum Brain Mapp 37:547-557, 2016. © 2015 Wiley Periodicals, Inc....

  9. Brain areas activated by uncertain reward-based decision-making in healthy volunteers

    Institute of Scientific and Technical Information of China (English)

    Zongjun Guo; Juan Chen; Shien Liu; Yuhuan Li; Bo Sun; Zhenbo Gao

    2013-01-01

    Reward-based decision-making has been found to activate several brain areas, including the ven-trolateral prefrontal lobe, orbitofrontal cortex, anterior cingulate cortex, ventral striatum, and meso-limbic dopaminergic system. In this study, we observed brain areas activated under three degrees of uncertainty in a reward-based decision-making task (certain, risky, and ambiguous). The tasks were presented using a brain function audiovisual stimulation system. We conducted brain scans of 15 healthy volunteers using a 3.0T magnetic resonance scanner. We used SPM8 to analyze the location and intensity of activation during the reward-based decision-making task, with respect to the three conditions. We found that the orbitofrontal cortex was activated in the certain reward con-dition, while the prefrontal cortex, precentral gyrus, occipital visual cortex, inferior parietal lobe, ce-rebel ar posterior lobe, middle temporal gyrus, inferior temporal gyrus, limbic lobe, and midbrain were activated during the ‘risk’ condition. The prefrontal cortex, temporal pole, inferior temporal gyrus, occipital visual cortex, and cerebel ar posterior lobe were activated during ambiguous deci-sion-making. The ventrolateral prefrontal lobe, frontal pole of the prefrontal lobe, orbitofrontal cortex, precentral gyrus, inferior temporal gyrus, fusiform gyrus, supramarginal gyrus, inferior parietal lo-bule, and cerebel ar posterior lobe exhibited greater activation in the‘risk’ than in the‘certain’ con-dition (P<0.05). The frontal pole and dorsolateral region of the prefrontal lobe, as wel as the ce-rebel ar posterior lobe, showed significantly greater activation in the ‘ambiguous’ condition com-pared to the ‘risk’ condition (P < 0.05). The prefrontal lobe, occipital lobe, parietal lobe, temporal lobe, limbic lobe, midbrain, and posterior lobe of the cerebel um were activated during deci-sion-making about uncertain rewards. Thus, we observed different levels and regions of

  10. Berberine inhibits inflammatory activation of rat brain microglia

    Institute of Scientific and Technical Information of China (English)

    Kyong Nyon Nam; Jae-Hong Kim; Hoon-Ji Jung; Jung-Mi Park; Sang-Kwan Moon; Young-Suk Kim; Sun Yeou Kim; Eunjoo H.Lee

    2010-01-01

    Chronic activation of microglial cells endangers neuronal survival through the release of various proinflammatory and neurotoxic factors.Berberine,the effective ingredient of Coptidis Rhizoma and Cortex Phellodendri,has a wide range of pharmacological functions,including anti-inflammatory,anti-atherosclerotic and anti-cancer effects.The neuroprotective potential of berberine has previously been demonstrated.The present study aimed to examine whether berberine could repress microglial activation and can be considered a potential therapeutic candidate to target neurodegenerative diseases.Primary microglial cells and BV2 microglial cells were cultured and stimulated with bacterial lipopolysaccharide(LPS).Berberine chloride was treated prior to LPS or simultaneously with LPS stimulation.Results revealed that berberine was effective at inhibiting nitric oxide release from primary microglial cells when cells were exposed to the compound prior to LPS or simultaneously with LPS.It also reduced the LPS-stimulated production of tumor necrosis factor-α,interleukin-1β,prostaglandin E2,and intracellular reactive oxygen species and nuclear factor-kappa activation.Additionally,berberine reduced nitric oxide release from microglia stimulated with interferon-γ and amyloid β.These results suggest that berberine provides neuroprotection by reducing the production of various neurotoxic molecules from activated microglia.

  11. Brain activity related to integrative processes in visual object recognition

    DEFF Research Database (Denmark)

    Gerlach, Christian; Aaside, C T; Humphreys, G W;

    2002-01-01

    We report evidence from a PET activation study that the inferior occipital gyri (likely to include area V2) and the posterior parts of the fusiform and inferior temporal gyri are involved in the integration of visual elements into perceptual wholes (single objects). Of these areas, the fusiform a...

  12. Activation of the human brain by monetary reward

    NARCIS (Netherlands)

    Thut, G; Schultz, W; Roelcke, U; Nienhusmeier, M; Missimer, J; Maguire, RP; Leenders, KL

    1997-01-01

    WITH the purpose of studying neural activation associated with reward processing in humans, we measured regional cerebral blood flow in 10 right-handed healthy subjects performing a delayed go-no go task in two different reinforcement conditions. Correct responses were either rewarded by money or a

  13. The relationship between inflammatory activity and brain atrophy in natalizumab treated patients

    Energy Technology Data Exchange (ETDEWEB)

    Magraner, M., E-mail: majomagbe@ono.com [Multiple Sclerosis Unit, Neurology Service, Hospital Universitari i Politecnic La Fe, Bulevar Sur s/n, 46026 Valencia (Spain); Coret, F., E-mail: coret_fra@gva.es [Multiple Sclerosis Unit, Neurology Service, Hospital Clinic de Valencia, Avda Blasco Ibanez 17, 46010 Valencia (Spain); Casanova, B., E-mail: Casanova_bon@gva.es [Multiple Sclerosis Unit, Neurology Service, Hospital Universitari i Politecnic La Fe, Bulevar Sur s/n, 46026 Valencia (Spain)

    2012-11-15

    Objective: To assess the evolution of brain atrophy and its relationship with inflammatory activity in RRMS patients treated with natalizumab. Methods: Eighteen RRMS patients were prospectively followed up for 18 months after starting natalizumab therapy. Patients were monitored monthly and assessed for signs of relapses, adverse events or disability increase. MRI scans were performed before starting natalizumab and every six months. Cross-sectional T2 lesion volume (T2LV) and the normalized brain volume (NBV) at baseline and 18 months MRI scans were calculated using the Steronauta{sup Registered-Sign} and SIENAx softwares, respectively. Longitudinal Percentage of Brain Volume Change (PBVC) was estimated with SIENA. Linkage between inflammatory activity and brain atrophy was studied. Results: Natalizumab reduced ARR by 67% and cumulative CEL by 87.5%. T2 lesion volume decreased from 1000 mm{sup 3}, to 960 mm{sup 3} (p = 0.006) and NBV decreased from 1.55 Multiplication-Sign 10{sup 5} mm{sup 3} to 1.42 Multiplication-Sign 10{sup 5} mm{sup 3} (p = 0.025). Global PBVC from baseline to 18 months was -2.5%, predominantly during the first six months (0-6 months PBVC -1.7%; 6-12 months PBVC -0.74%; 12-18 months PBVC -0.50%). The number of relapses before treatment was correlated to the PBVC during the first semester (Pearson's coefficient -0.520, p = 0.003), while the number of basal CEL or baseline T2LV did not correlate with brain atrophy rate. During follow-up, nine patients had clinical or radiological inflammatory activity. Their PBVC was significantly higher in the first semester (-2.3% to -1.1%, p = 0.002). Conclusions: Natalizumab reduced relapse rate and CEL in MRI. Brain atrophy predominated in the first semester and was related to previous inflammatory activity.

  14. 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

    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......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......(79)) were analysed, as was fatty acid oxidation (FAO). Finally, we electroporated a Bdnf vector into the tibialis cranialis muscle of mice. RESULTS: BDNF mRNA and protein expression were increased in human skeletal muscle after exercise, but muscle-derived BDNF appeared not to be released...

  15. Why and how physical activity promotes experience-induced brain plasticity

    Directory of Open Access Journals (Sweden)

    Gerd eKempermann

    2010-12-01

    Full Text Available Adult hippocampal neurogenesis is an unusual case of brain plasticity, since new neurons (and not just neurites and synapses are added to the network in an activity-dependent way. At the behavioral level the plasticity-inducing stimuli include both physical and cognitive activity. In reductionistic animal studies these types of activity can be studied separately in paradigms like voluntary wheel running and environmental enrichment. In both of these, adult neurogenesis is increased but the net effect is primarily due to different mechanisms at the cellular level. Locomotion appears to stimulate the precursor cells, from which adult neurogenesis originates, to increased proliferation and maintenance over time, whereas environmental enrichment, as well as learning, predominantly promotes survival of immature neurons, that is the progeny of the proliferating precursor cells. Surprisingly, these effects are additive: boosting the potential for adult neurogenesis by physical activity increases the recruitment of cells following cognitive stimulation in an enriched environment. Why is that? We argue that locomotion actually serves as an intrinsic feedback mechanism, signaling to the brain, including its neural precursor cells, that the likelihood of cognitive challenges increases. In the wild (other than in front of a TV, no separation of physical and cognitive activity occurs. Physical activity might thus be much more than a generally healthy garnish to leading an active life but an evolutionarily fundamental aspect of activity, which is needed to provide the brain and its systems of plastic adaptation with the appropriate regulatory input and feedback.

  16. Brain Activation and Psychomotor Speed in Middle-Aged Patients with Type 1 Diabetes: Relationships with Hyperglycemia and Brain Small Vessel Disease

    Directory of Open Access Journals (Sweden)

    Misun Hwang

    2016-01-01

    Full Text Available Slower psychomotor speed is very common in patients with type 1 diabetes mellitus (T1D, but the underlying mechanisms are not clear. We propose that hyperglycemia is associated with slower psychomotor speed via disruption of brain activation. Eighty-five adults (48% women, mean age: 49.0 years, mean duration: 40.8 with childhood onset T1D were recruited for this cross-sectional study. Median response time in seconds (longer = worse performance and brain activation were measured while performing a psychomotor speed task. Exposure to hyperglycemia, measured as glycosylated hemoglobin A1c, was associated with longer response time and with higher activation in the inferior frontal gyrus and primary sensorimotor and dorsal cingulate cortex. Higher activation in inferior frontal gyrus, primary sensorimotor cortex, thalamus, and cuneus was related to longer response times; in contrast, higher activation in the superior parietal lobe was associated with shorter response times. Associations were independent of small vessel disease in the brain or other organs. In this group of middle-aged adults with T1D, the pathway linking chronic hyperglycemia with slower processing speed appears to include increased brain activation, but not small vessel disease. Activation in the superior parietal lobe may compensate for dysregulation in brain activation in the presence of hyperglycemia.

  17. Performance of an active electric bearing for rotary micromotors

    International Nuclear Information System (INIS)

    An electric bearing used to support a micromachined rotor of variable-capacitance motors was designed and tested in order to study the characteristics of this frictionless bearing. Electrostatic suspension of a ring-shaped rotor in five degrees of freedom is required to eliminate the mechanical bearing and thus the friction and wear between the rotor and the substrate. Bulk microfabrication-based glass/silicon/glass bonding is chosen for this device, allowing the fabrication of large area sense capacitors and rotor, which make the device potentially suitable for the development of an electrostatically suspended micromachined gyroscope. The device and its basic operating principle are described, as well as the dynamics of the rotor and basic design considerations of the electric bearing system. A theoretical relationship to relate the characteristics of a classical lag–lead compensator to the stiffness properties of the electric bearing is developed to explain the experimental bearing measurements. The experimental results of closed-loop frequency response, suspension stiffness and drive voltage effects are presented and discussed for the bearing operated initially in the atmospheric environment. The performance of a tri-axial electrostatic accelerometer has also been experimentally investigated on the prototype of the electric bearing system

  18. Electric and electrochemical properties of catalytically active oxygen electrode materials

    NARCIS (Netherlands)

    Burggraaf, A.J.; Dijk, van M.P.; Vries, de K.J.

    1986-01-01

    The electrical conductivity has been investigated of some oxygen ion and mixed conducting materials. Electrodes are prepared from thin sputtered layers of these oxides combined with a small Au or Pt strip. The kinetics of the oxygen reaction has been studied for temperatures of 820–1020 K and PO2 va

  19. Updated summary of state electric industry restructuring activities

    International Nuclear Information System (INIS)

    The pace of electric industry restructuring has become more deliberate in 1997. This brief article and accompanying table describe the advance of restructuring across the US as of early September 1997, and continue the series of topical summaries by exploring retail competition pilot programs and lessons learned. Eight states have now enacted substantive restructuring legislation, Maine and Nevada were recently added to the list

  20. Regional brain activation associated with addiction of computer games in adolescents

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Y. H.; Shin, O. J.; Ko, Y. W.; Kim, H. J.; Yun, M. J.; Lee, J. D. [College of Medicine, Yonsei Univ., Seoul (Korea, Republic of)

    2001-07-01

    Excessive computer game (CG) playing may cause not only behavioral addiction, but also potential negative effects on developing brain. It is necessary to reveal how brain is affected by excessive use of CG playing and behavioral addiction of it. By using PET, we address the issue seeking to identifying patterns of regional brain activation associated with behavioral addiction and excessive use of CG playing by adolescents. 6 normal control and 8 adolescents who were met by the criteria of behavioral addiction on the survey as addiction groups with an addiction of CG playing were participated. Initial screening survey which is the adapted version of DSM-IV for pathologic gambling was done. PET were performed twice in each participants both during resting state and after 20 min playing of CG. Psychological test including Youth Self Report (YSR), memory and attention test and vocabulary item from KWAIS were performed. Scores of the vocabulary item from KWAIS and social competence from YSR were significantly lower in the addiction group. On PET, addiction group showed higher resting metabolism on inferior frontal, premotor, prefrontal and superior temporal area. Adolescents with addiction of CG revealed different patterns of regional brain activation comparing to control groups. These suggest behavioral addiction and excessive use of CG may result in functional alteration of developing brain in adolescents.

  1. Distinct resting-state brain activity in patients with functional constipation.

    Science.gov (United States)

    Zhu, Qiang; Cai, Weiwei; Zheng, Jianyong; Li, Guanya; Meng, Qianqian; Liu, Qiaoyun; Zhao, Jizheng; von Deneen, Karen M; Wang, Yuanyuan; Cui, Guangbin; Duan, Shijun; Han, Yu; Wang, Huaning; Tian, Jie; Zhang, Yi; Nie, Yongzhan

    2016-10-01

    Functional constipation (FC) is a common functional gastrointestinal disorder (FGID) with a higher prevalence in clinical practice. The primary brain regions involved in emotional arousal regulation, somatic, sensory and motor control processing have been identified with neuroimaging in FGID. It remains unclear how these factors interact to influence the baseline brain activity of patients with FC. In the current study, we combined resting-state fMRI (RS-fMRI) with Granger causality analysis (GCA) to investigate the causal interactions of the brain areas in 14 patients with FC and in 26 healthy controls (HC). Our data showed significant differences in baseline brain activities in a number of major brain regions implicated in emotional process modulation (i.e. dorsal anterior cingulate cortex-dACC, anterior insula-aINS, orbitofrontal cortex-OFC, hippocampus-HIPP), somatic and sensory processing, and motor control (i.e., supplementary motor area-SMA, precentral gyrus-PreCen) (Ppropel limbic regions at the aINS and HIPP to induce abnormal emotional processing regulating visceral responses; and weaker effective connectivity from the SMA and PreCen, which are regions involved with somatic, sensory and motor control, propel the aINS and HIPP, suggesting abnormalities of sensory and behavioral responses. Such information of basal level functional abnormalities expands our current understanding of neural mechanisms underlying functional constipation.

  2. Regional brain activation associated with addiction of computer games in adolescents

    International Nuclear Information System (INIS)

    Excessive computer game (CG) playing may cause not only behavioral addiction, but also potential negative effects on developing brain. It is necessary to reveal how brain is affected by excessive use of CG playing and behavioral addiction of it. By using PET, we address the issue seeking to identifying patterns of regional brain activation associated with behavioral addiction and excessive use of CG playing by adolescents. 6 normal control and 8 adolescents who were met by the criteria of behavioral addiction on the survey as addiction groups with an addiction of CG playing were participated. Initial screening survey which is the adapted version of DSM-IV for pathologic gambling was done. PET were performed twice in each participants both during resting state and after 20 min playing of CG. Psychological test including Youth Self Report (YSR), memory and attention test and vocabulary item from KWAIS were performed. Scores of the vocabulary item from KWAIS and social competence from YSR were significantly lower in the addiction group. On PET, addiction group showed higher resting metabolism on inferior frontal, premotor, prefrontal and superior temporal area. Adolescents with addiction of CG revealed different patterns of regional brain activation comparing to control groups. These suggest behavioral addiction and excessive use of CG may result in functional alteration of developing brain in adolescents

  3. BrainModes: a principled approach to modeling and measuring large-scale neuronal activity.

    Science.gov (United States)

    Breakspear, Michael J; Daffertshofer, Andreas; Ritter, Petra

    2009-09-30

    Complex systems, such as the brain, exhibit multiple levels of organization due to processes which support the separation of scales across time and/or space. That is, cooperative phenomena--or "modes" of activity--occurring at one scale give rise to coherent spatiotemporal structures at a coarser scale. In turn, structures at the coarser scale constrain--and hence influence--emerging activity at a finer scale. BrainModes is an annual scientific summit which seeks to bring together experimental, computational and theoretical neuroscientists engaged at different levels of organization, with the goal of advancing a principled approach to understanding brain function based on the concept of cooperative phenomena in complex systems. Phenomena of particular interest include synchronization, stochastic influences, and spatiotemporal processes in both healthy and pathological states such as seizures. This Special Issue reports the 2008 BrainModes Workshop, held in Amsterdam (December 2008) which focused on the application of this framework to the analysis of brain oscillations and synchronization phenomena across time scales. PMID:19607859

  4. Analysis of a phase synchronized functional network based on the rhythm of brain activities

    Institute of Scientific and Technical Information of China (English)

    Li Ling; Jin Zhen-Lan; Li Bin

    2011-01-01

    Rhythm of brain activities represents oscillations of postsynaptic potentials in neocortex, therefore it can serve as an indicator of the brain activity state. In order to check the connectivity of brain rhythm, this paper develops a new method of constructing functional network based on phase synchronization. Electroencephalogram (EEG) data were collected while subjects looking at a green cross in two states, performing an attention task and relaxing with eyes-open. The EEG from these two states was filtered by three band-pass filters to obtain signals of theta (4-7 Hz),alpha (8-13 Hz) and beta (14-30 Hz) bands. Mean resultant length was used to estimate strength of phase synchronization in three bands to construct networks of both states, and mean degree K and cluster coefficient C of networks were calculated as a function of threshold. The result shows higher cluster coefficient in the attention state than in the eyes-open state in all three bands, suggesting that cluster coefficient reflects brain state. In addition, an obvious fronto-parietal network is found in the attention state, which is a well-known attention network. These results indicate that attention modulates the fronto-parietal connectivity in different modes as compared with the eyes-open state. Taken together this method is an objective and important tool to study the properties of neural networks of brain rhythm.

  5. Chick embryos have the same pattern of hypoxic lower-brain activation as fetal mammals.

    Science.gov (United States)

    Landry, Jeremy P; Hawkins, Connor; Lee, Aaron; Coté, Alexandra; Balaban, Evan; Pompeiano, Maria

    2016-01-01

    cFos expression (indicating a particular kind of neuronal activation) was examined in embryonic day (E) 18 chick embryos after exposure to 4 h of either normoxia (21% O2), modest hypoxia (15% O2), or medium hypoxia (10% O2). Eight regions of the brainstem and hypothalamus were surveyed, including seven previously shown to respond to hypoxia in late-gestation mammalian fetuses (Breen et al., 1997; Nitsos and Walker, 1999b). Hypoxia-related changes in chick embryo brain activation mirrored those found in fetal mammals with the exception of the medullary Raphe, which showed decreased hypoxic activation, compared with no change in mammals. This difference may be explained by the greater anapyrexic responses of chick embryos relative to mammalian fetuses. Activation in the A1/C1 region was examined in more detail to ascertain whether an O2-sensitive subpopulation of these cells containing heme oxygenase 2 (HMOX2) may drive hypoxic brain responses before the maturation of peripheral O2-sensing. HMOX2-positive and -negative catecholaminergic cells and interdigitating noncatecholaminergic HMOX2-positive cells all showed significant changes in cFos expression to hypoxia, with larger population responses seen in the catecholaminergic cells. Hypoxia-induced activation of lower-brain regions studied here was significantly better correlated with activation of the nucleus of the solitary tract (NTS) than with that of HMOX2-containing A1/C1 neurons. Together, these observations suggest that (1) the functional circuitry controlling prenatal brain responses to hypoxia is strongly conserved between birds and mammals, and (2) NTS neurons are a more dominant driving force for prenatal hypoxic cFos brain responses than O2-sensing A1/C1 neurons.

  6. Decoding Subjective Intensity of Nociceptive Pain from Pre-stimulus and Post-stimulus Brain Activities.

    Science.gov (United States)

    Tu, Yiheng; Tan, Ao; Bai, Yanru; Hung, Yeung Sam; Zhang, Zhiguo

    2016-01-01

    Pain is a highly subjective experience. Self-report is the gold standard for pain assessment in clinical practice, but it may not be available or reliable in some populations. Neuroimaging data, such as electroencephalography (EEG) and functional magnetic resonance imaging (fMRI), have the potential to be used to provide physiology-based and quantitative nociceptive pain assessment tools that complements self-report. However, existing neuroimaging-based nociceptive pain assessments only rely on the information in pain-evoked brain activities, but neglect the fact that the perceived intensity of pain is also encoded by ongoing brain activities prior to painful stimulation. Here, we proposed to use machine learning algorithms to decode pain intensity from both pre-stimulus ongoing and post-stimulus evoked brain activities. Neural features that were correlated with intensity of laser-evoked nociceptive pain were extracted from high-dimensional pre- and post-stimulus EEG and fMRI activities using partial least-squares regression (PLSR). Further, we used support vector machine (SVM) to predict the intensity of pain from pain-related time-frequency EEG patterns and BOLD-fMRI patterns. Results showed that combining predictive information in pre- and post-stimulus brain activities can achieve significantly better performance in classifying high-pain and low-pain and in predicting the rating of perceived pain than only using post-stimulus brain activities. Therefore, the proposed pain prediction method holds great potential in basic research and clinical applications. PMID:27148029

  7. Decoding Subjective Intensity of Nociceptive Pain from Pre-stimulus and Post-stimulus Brain Activities

    Directory of Open Access Journals (Sweden)

    Yiheng eTu

    2016-04-01

    Full Text Available Pain is a highly subjective experience. Self-report is the gold standard for pain assessment in clinical practice, but it may not be available or reliable in some populations. Neuroimaging data, such as electroencephalography (EEG and functional magnetic resonance imaging (fMRI, have the potential to be used to provide physiology-based and quantitative nociceptive pain assessment tools that complements self-report. However, existing neuroimaging-based nociceptive pain assessments only rely on the information in pain-evoked brain activities, but neglect the fact that the perceived intensity of pain is also encoded by ongoing brain activities prior to painful stimulation. Here, we proposed to use machine learning algorithms to decode pain intensity from both pre-stimulus ongoing and post-stimulus evoked brain activities. Neural features that were correlated with intensity of laser-evoked nociceptive pain were extracted from high-dimensional pre- and post-stimulus EEG and fMRI activities using partial least-squares regression (PLSR. Further, we used support vector machine (SVM to predict the intensity of pain from pain-related time-frequency EEG patterns and BOLD-fMRI patterns. Results showed that combining predictive information in pre- and post-stimulus brain activities can achieve significantly better performance in classifying high-pain and low-pain and in predicting the rating of perceived pain than only using post-stimulus brain activities. Therefore, the proposed pain prediction method holds great potential in basic research and clinical applications.

  8. Effect of target probability on pre-stimulus brain activity.

    Science.gov (United States)

    Lucci, G; Berchicci, M; Perri, R L; Spinelli, D; Di Russo, F

    2016-05-13

    Studies on perceptual decision-making showed that manipulating the proportion of target and non-target stimuli affects the behavioral performance. Tasks with high frequency of targets are associated to faster response times (RTs) conjunctively to higher number of errors (reflecting a response bias characterized by speed/accuracy trade-off) when compared to conditions with low frequency of targets. Electroencephalographic studies well described modulations of post-stimulus event-related potentials as effect of the stimulus probability; in contrast, in the present study we focused on the pre-stimulus preparatory activities subtending the response bias. Two versions of a Go/No-go task characterized by different proportion of Go stimuli (88% vs. 12%) were adopted. In the task with frequent go trials, we observed a strong enhancement in the motor preparation as indexed by the Bereitschaftspotential (BP, previously associated with activity within the supplementary motor area), faster RTs, and larger commission error rate than in the task with rare go trials. Contemporarily with the BP, a right lateralized prefrontal negativity (lateral pN, previously associated with activity within the dorsolateral prefrontal cortex) was larger in the task with rare go trial. In the post-stimulus processing stage, we confirmed that the N2 and the P3 components were larger for rare trials, irrespective of the Go/No-go stimulus category. The increase of activities recorded in the preparatory phase related to frequency of targets is consistent with the view proposed in accumulation models of perceptual decision for which target frequency affects the subjective baseline, reducing the distance between the starting-point and the response boundary, which determines the response speed. PMID:26912279

  9. Fluvoxamine alters the activity of energy metabolism enzymes in the brain

    Directory of Open Access Journals (Sweden)

    Gabriela K. Ferreira

    2014-09-01

    Full Text Available Objective: Several studies support the hypothesis that metabolism impairment is involved in the pathophysiology of depression and that some antidepressants act by modulating brain energy metabolism. Thus, we evaluated the activity of Krebs cycle enzymes, the mitochondrial respiratory chain, and creatine kinase in the brain of rats subjected to prolonged administration of fluvoxamine. Methods: Wistar rats received daily administration of fluvoxamine in saline (10, 30, and 60 mg/kg for 14 days. Twelve hours after the last administration, rats were killed by decapitation and the prefrontal cortex, cerebral cortex, hippocampus, striatum, and cerebellum were rapidly isolated. Results: The activities of citrate synthase, malate dehydrogenase, and complexes I, II-III, and IV were decreased after prolonged administration of fluvoxamine in rats. However, the activities of complex II, succinate dehydrogenase, and creatine kinase were increased. Conclusions: Alterations in activity of energy metabolism enzymes were observed in most brain areas analyzed. Thus, we suggest that the decrease in citrate synthase, malate dehydrogenase, and complexes I, II-III, and IV can be related to adverse effects of pharmacotherapy, but long-term molecular adaptations cannot be ruled out. In addition, we demonstrated that these changes varied according to brain structure or biochemical analysis and were not dose-dependent.

  10. Entrainment of chaotic activities in brain and heart during MBSR mindfulness training.

    Science.gov (United States)

    Gao, Junling; Fan, Jicong; Wu, Bonnie Wai Yan; Zhang, Zhiguo; Chang, Chunqi; Hung, Yeung-Sam; Fung, Peter Chin Wan; Sik, Hin Hung

    2016-03-11

    The activities of the brain and the heart are dynamic, chaotic, and possibly intrinsically coordinated. This study aims to investigate the effect of Mindfulness-Based Stress Reduction (MBSR) program on the chaoticity of electronic activities of the brain and the heart, and to explore their potential correlation. Electroencephalogram (EEG) and electrocardiogram (ECG) were recorded at the beginning of an 8-week standard MBSR training course and after the course. EEG spectrum analysis was carried out, wavelet entropies (WE) of EEG (together with reconstructed cortical sources) and heart rate were calculated, and their correlation was investigated. We found enhancement of EEG power of alpha and beta waves and lowering of delta waves power during MBSR training state as compared to normal resting state. Wavelet entropy analysis indicated that MBSR mindfulness meditation could reduce the chaotic activities of both EEG and heart rate as a change of state. However, longitudinal change of trait may need more long-term training. For the first time, our data demonstrated that the chaotic activities of the brain and the heart became more coordinated during MBSR training, suggesting that mindfulness training may increase the entrainment between mind and body. The 3D brain regions involved in the change in mental states were identified. PMID:26784361

  11. Entrainment of chaotic activities in brain and heart during MBSR mindfulness training.

    Science.gov (United States)

    Gao, Junling; Fan, Jicong; Wu, Bonnie Wai Yan; Zhang, Zhiguo; Chang, Chunqi; Hung, Yeung-Sam; Fung, Peter Chin Wan; Sik, Hin Hung

    2016-03-11

    The activities of the brain and the heart are dynamic, chaotic, and possibly intrinsically coordinated. This study aims to investigate the effect of Mindfulness-Based Stress Reduction (MBSR) program on the chaoticity of electronic activities of the brain and the heart, and to explore their potential correlation. Electroencephalogram (EEG) and electrocardiogram (ECG) were recorded at the beginning of an 8-week standard MBSR training course and after the course. EEG spectrum analysis was carried out, wavelet entropies (WE) of EEG (together with reconstructed cortical sources) and heart rate were calculated, and their correlation was investigated. We found enhancement of EEG power of alpha and beta waves and lowering of delta waves power during MBSR training state as compared to normal resting state. Wavelet entropy analysis indicated that MBSR mindfulness meditation could reduce the chaotic activities of both EEG and heart rate as a change of state. However, longitudinal change of trait may need more long-term training. For the first time, our data demonstrated that the chaotic activities of the brain and the heart became more coordinated during MBSR training, suggesting that mindfulness training may increase the entrainment between mind and body. The 3D brain regions involved in the change in mental states were identified.

  12. Prion Protein M129V Polymorphism Affects Retrieval-Related Brain Activity

    Science.gov (United States)

    Buchmann, Andreas; Mondadori, Christian R. A.; Hanggi, Jurgen; Aerni, Amanda; Vrticka, Pascal; Luechinger, Roger; Boesiger, Peter; Hock, Christoph; Nitsch, Roger M.; de Quervain, Dominique J.-F.; Papassotiropoulos, Andreas; Henke, Katharina

    2008-01-01

    The prion protein Met129Val polymorphism has recently been related to human long-term memory with carriers of either the 129[superscript MM] or the 129[superscript MV] genotype recalling 17% more words than 129[superscript VV] carriers at 24 h following learning. Here, we sampled genotype differences in retrieval-related brain activity at 30 min…

  13. Development of a Conceptual Model to Predict Physical Activity Participation in Adults with Brain Injuries

    Science.gov (United States)

    Driver, Simon

    2008-01-01

    The purpose was to examine psychosocial factors that influence the physical activity behaviors of adults with brain injuries. Two differing models, based on Harter's model of self-worth, were proposed to examine the relationship between perceived competence, social support, physical self-worth, affect, and motivation. Adults numbering 384 with…

  14. The Physiochemistry of Capped Nanosilver Predicts Its Biological Activity in Rat Brain Endothelial Cells (REBEC4)

    Science.gov (United States)

    The “capping” or coating of nanosilver (nanoAg) extends its potency by limiting its oxidation and aggregation and stabilizing its size and shape. The ability of such coated nanoAg to alter the permeability and activate oxidative stress pathways in rat brain endothelia...

  15. Brain correlates underlying creative thinking: EEG alpha activity in professional vs. novice dancers.

    Science.gov (United States)

    Fink, Andreas; Graif, Barbara; Neubauer, Aljoscha C

    2009-07-01

    Neuroscientific research on creativity has revealed valuable insights into possible brain correlates underlying this complex mental ability domain. However, most of the studies investigated brain activity during the performance of comparatively simple (verbal) type of tasks and the majority of studies focused on samples of the normal population. In this study we investigate EEG activity in professional dancers (n=15) who have attained a high level of expertise in this domain. This group was compared with a group of novices (n=17) who have only basic experience in dancing and completed no comprehensive training in this field. The EEG was recorded during performance of two different dancing imagery tasks which differed with respect to creative demands. In the first task participants were instructed to mentally perform a dance which should be as unique and original as possible (improvisation dance). In the waltz task they were asked to imagine dancing the waltz, a standard dance which involves a sequence of monotonous steps (lower creative demands). In addition, brain activity was also measured during performance of the Alternative Uses test. We observed evidence that during the generation of alternative uses professional dancers show stronger alpha synchronization in posterior parietal brain regions than novice dancers. During improvisation dance, professional dancers exhibited more right-hemispheric alpha synchronization than the group of novices did, while during imagining dancing the waltz no significant group differences emerged. The findings complement and extend existing findings on the relationship between EEG alpha activity and creative thinking. PMID:19269335

  16. Simultaneous EMG-Functional MRI Recordings Can Directly Relate Hyperkinetic Movements to Brain Activity

    NARCIS (Netherlands)

    van Rootselaar, Anne-Fleur; Maurits, Natasha M.; Renken, Remco; Koelman, Johannes H. T. M.; Hoogduin, Johannes M.; Leenders, Klaus L.; Tijssen, Marina A. J.

    2008-01-01

    Objective: To apply and validate the use of electromyogram (EMG) recorded during functional magnetic resonance imaging (fMRI) in patients with movement disorders, to directly relate involuntary movements to brain activity. Methods: Eight "familial cortical myoclonic tremor with epilepsy" (FCMTE) pat

  17. 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

  18. Brain functional near infrared spectroscopy in human infants : cerebral cortical haemodynamics coupled to neuronal activation in response to sensory stimulation

    OpenAIRE

    Bartocci, Marco

    2006-01-01

    The assessment of cortical activation in the neonatal brain is crucial in the study of brain development, as it provides precious information for how the newborn infant processes external or internal stimuli. Thus far functional studies of neonates aimed to assess cortical responses to certain external stimuli are very few, due to the lack of suitable techniques to monitor brain activity of the newborn. Near Infrared Spectroscopy (NIRS) has been found to be suitable for func...

  19. Does erotic stimulus presentation design affect brain activation patterns? Event-related vs. blocked fMRI designs

    OpenAIRE

    Klemen Jane; Vollstädt-Klein Sabine; Bühler Mira; Smolka Michael N

    2008-01-01

    Abstract Background Existing brain imaging studies, investigating sexual arousal via the presentation of erotic pictures or film excerpts, have mainly used blocked designs with long stimulus presentation times. Methods To clarify how experimental functional magnetic resonance imaging (fMRI) design affects stimulus-induced brain activity, we compared brief event-related presentation of erotic vs. neutral stimuli with blocked presentation in 10 male volunteers. Results Brain activation differed...

  20. Cognitive activity, cognitive function, and brain diffusion characteristics in old age.

    Science.gov (United States)

    Arfanakis, Konstantinos; Wilson, Robert S; Barth, Christopher M; Capuano, Ana W; Vasireddi, Anil; Zhang, Shengwei; Fleischman, Debra A; Bennett, David A

    2016-06-01

    The objective of this work was to test the hypotheses that a) more frequent cognitive activity in late life is associated with higher brain diffusion anisotropy and lower trace of the diffusion tensor, and b) brain diffusion characteristics partially mediate the association of late life cognitive activity with cognition. As part of a longitudinal cohort study, 379 older people without dementia rated their frequency of participation in cognitive activities, completed a battery of cognitive function tests, and underwent diffusion tensor imaging. We used tract-based spatial statistics to test the association between late life cognitive activity and brain diffusion characteristics. Clusters with statistically significant findings defined regions of interest in which we tested the hypothesis that diffusion characteristics partially mediate the association of late life cognitive activity with cognition. More frequent cognitive activity in late life was associated with higher level of global cognition after adjustment for age, sex, education, and indicators of early life cognitive enrichment (p = 0.001). More frequent cognitive activity was also related to higher fractional anisotropy in the left superior and inferior longitudinal fasciculi, left fornix, and corpus callosum, and lower trace in the thalamus (p < 0.05, FWE-corrected). After controlling for fractional anisotropy or trace from these regions, the regression coefficient for the association of late life cognitive activity with cognition was reduced by as much as 26 %. These findings suggest that the association of late life cognitive activity with cognition may be partially mediated by brain diffusion characteristics. PMID:25982658

  1. Upregulation of calpain activity precedes tau phosphorylation and loss of synaptic proteins in Alzheimer's disease brain.

    Science.gov (United States)

    Kurbatskaya, Ksenia; Phillips, Emma C; Croft, Cara L; Dentoni, Giacomo; Hughes, Martina M; Wade, Matthew A; Al-Sarraj, Safa; Troakes, Claire; O'Neill, Michael J; Perez-Nievas, Beatriz G; Hanger, Diane P; Noble, Wendy

    2016-03-31

    Alterations in calcium homeostasis are widely reported to contribute to synaptic degeneration and neuronal loss in Alzheimer's disease. Elevated cytosolic calcium concentrations lead to activation of the calcium-sensitive cysteine protease, calpain, which has a number of substrates known to be abnormally regulated in disease. Analysis of human brain has shown that calpain activity is elevated in AD compared to controls, and that calpain-mediated proteolysis regulates the activity of important disease-associated proteins including the tau kinases cyclin-dependent kinase 5 and glycogen kinase synthase-3. Here, we sought to investigate the likely temporal association between these changes during the development of sporadic AD using Braak staged post-mortem brain. Quantification of protein amounts in these tissues showed increased activity of calpain-1 from Braak stage III onwards in comparison to controls, extending previous findings that calpain-1 is upregulated at end-stage disease, and suggesting that activation of calcium-sensitive signalling pathways are sustained from early stages of disease development. Increases in calpain-1 activity were associated with elevated activity of the endogenous calpain inhibitor, calpastatin, itself a known calpain substrate. Activation of the tau kinases, glycogen-kinase synthase-3 and cyclin-dependent kinase 5 were also found to occur in Braak stage II-III brain, and these preceded global elevations in tau phosphorylation and the loss of post-synaptic markers. In addition, we identified transient increases in total amyloid precursor protein and pre-synaptic markers in Braak stage II-III brain, that were lost by end stage Alzheimer's disease, that may be indicative of endogenous compensatory responses to the initial stages of neurodegeneration. These findings provide insight into the molecular events that underpin the progression of Alzheimer's disease, and further highlight the rationale for investigating novel treatment

  2. Testosterone is inversely related to brain activity during emotional inhibition in schizophrenia.

    Directory of Open Access Journals (Sweden)

    Ans Vercammen

    Full Text Available Sex steroids affect cognitive function as well as emotion processing and regulation. They may also play a role in the pathophysiology of schizophrenia. However, the effects of sex steroids on cognition and emotion-related brain activation in schizophrenia are poorly understood. Our aim was to determine the extent to which circulating testosterone relates to brain activation in men with schizophrenia compared to healthy men during cognitive-emotional processing. We assessed brain activation in 18 men with schizophrenia and 22 age-matched healthy men during an emotional go/no-go task using fMRI and measured total serum testosterone levels on the same morning. We performed an ROI analysis to assess the relationship between serum testosterone and brain activation, focusing on cortical regions involved the emotional go/no-go task. Slower RT and reduced accuracy was observed when participants responded to neutral stimuli, while inhibiting responses to negative stimuli. Healthy men showed a robust increase in activation of the middle frontal gyrus when inhibiting responses to negative stimuli, but there was no significant association between activation and serum testosterone level in healthy men. Men with schizophrenia showed a less pronounced increase in activation when inhibiting responses to negative stimuli; however, they did show a strong inverse association between serum testosterone level and activation of the bilateral middle frontal gyrus and left insula. Additionally, increased accuracy during inhibition of response to negative words was associated with both higher serum testosterone levels and decreased activation of the middle frontal gyrus in men with schizophrenia only. We conclude that endogenous hormone levels, even within the normal range, may play an enhanced modulatory role in determining the neural and behavioural response during cognitive-emotional processing in schizophrenia.

  3. Dopaminergic modulation of the spectral characteristics in the rat brain oscillatory activity

    International Nuclear Information System (INIS)

    Highlights: ► The oscillatory activity recorded at different locations of the rat brain present a power law characteristic (PLC). ► Dopaminergic drugs are able to modify the power law spectral characteristic of the oscillatory activity. ► Drugs with opposite effects over the dopaminergic system (agonists/antagonists), induce opposite changes in the PLC. ► There is a fulcrum point for the modulation of the PLC around 20 Hz. ► The brain operates in a state of self-organized criticality (SOC) sensitive to dopaminergic modulation. - Abstract: Oscillatory activity can be widely recorded in the brain. It has been demonstrated to play an important role not only in the physiology of movement, perception and cognition, but also in the pathophysiology of a variety of diseases. In frequency domain, neurophysiological recordings show a power spectrum (PSD) following a log (PSD) ∝ log (f)−β, that reveals an intrinsic feature of many complex systems in nature: the presence of a scale-free dynamics characterized by a power-law component (PLC). Here we analyzed the influence of dopaminergic drugs over the PLC of the oscillatory activity recorded from different locations of the rat brain. Dopamine (DA) is a neurotransmitter that is required for a number of physiological functions like normal feeding, locomotion, posturing, grooming and reaction time. Alterations in the dopaminergic system cause vast effects in the dynamics of the brain activity, that may be crucial in the pathophysiology of neurological (like Parkinson’s disease) or psychiatric (like schizophrenia) diseases. Our results show that drugs with opposite effects over the dopaminergic system, induce opposite changes in the characteristics of the PLC: DA agonists/antagonists cause the PLC to swing around a fulcrum point in the range of 20 Hz. Changes in the harmonic component of the spectrum were also detected. However, differences between recordings are better explained by the modulation of the PLC than

  4. Age-related shifts in brain activity dynamics during task switching.

    Science.gov (United States)

    Jimura, Koji; Braver, Todd S

    2010-06-01

    Cognitive aging studies have suggested that older adults show declines in both sustained and transient cognitive control processes. However, previous neuroimaging studies have primarily focused on age-related change in the magnitude, but not temporal dynamics, of brain activity. The present study compared brain activity dynamics in healthy old and young adults during task switching. A mixed blocked/event-related functional magnetic resonance imaging design enabled separation of transient and sustained neural activity associated with cognitive control. Relative to young adults, older adults exhibited not only decreased sustained activity in the anterior prefrontal cortex (aPFC) during task-switching blocks but also increased transient activity on task-switch trials. Another pattern of age-related shift in dynamics was present in the lateral PFC (lPFC) and posterior parietal cortex (PPC), with younger adults showing a cue-related response during task-switch trials in lPFC and PPC, whereas older adults exhibited switch-related activation during the cue period in PPC only. In all 3 regions, these qualitatively distinct patterns of brain activity predicted qualitatively distinct patterns of behavioral performance across the 2 age groups. Together, these results suggest that older adults may shift from a proactive to reactive cognitive control strategy as a means of retaining relatively preserved behavioral performance in the face of age-related neurocognitive changes. PMID:19805420

  5. Correlation between electrical activity and various structures of Ge grain boundaries

    Energy Technology Data Exchange (ETDEWEB)

    Palais, O [Laboratoire TECSEN, UMR 6122-CNRS, Faculte des Sciences et Techniques de St Jerome, F-13397 Marseille, Cedex 20 (France); Lamzatouar, A [Laboratoire TECSEN, UMR 6122-CNRS, Faculte des Sciences et Techniques de St Jerome, F-13397 Marseille, Cedex 20 (France); Duparc, O B M Hardouin [LSI, UMR 7642-CNRS-CEA, Ecole Polytechnique, 91128 Palaiseau Cedex (France); Thibault, J [CEA/DRFMC, 17 rue des Martyrs, 38054 Grenoble (France); Chara, A [Laboratoire TECSEN, UMR 6122-CNRS, Faculte des Sciences et Techniques de St Jerome, F-13397 Marseille, Cedex 20 (France)

    2004-01-21

    The links between the electrical activity and the atomic structure of various Ge grain boundaries (GBs) are investigated. The atomic structure is studied using high resolution electron microscopy, while the electrical activity is evaluated thanks to the measurement of minority carrier lifetime by means of the contactless microwave phase shift technique. Results show that in the {sigma} = 51 GB the electrical activity depends on the atomic structure connected to the configuration of the grain boundary, i.e. tilt, twist or mixed. Lower energy structures such as {sigma} = 3 and 9 GBs appear not to be recombinant.

  6. Hypoxia-ischemia or excitotoxin-induced tissue plasminogen activator- dependent gelatinase activation in mice neonate brain microvessels.

    Directory of Open Access Journals (Sweden)

    Priscilla L Omouendze

    Full Text Available Hypoxia-ischemia (HI and excitotoxicity are validated causes of neonatal brain injuries and tissue plasminogen activator (t-PA participates in the processes through proteolytic and receptor-mediated pathways. Brain microvascular endothelial cells from neonates in culture, contain and release more t-PA and gelatinases upon glutamate challenge than adult cells. We have studied t-PA to gelatinase (MMP-2 and MMP-9 activity links in HI and excitotoxicity lesion models in 5 day-old pups in wild type and in t-PA or its inhibitor (PAI-1 genes inactivated mice. Gelatinolytic activities were detected in SDS-PAGE zymograms and by in situ fluorescent DQ-gelatin microscopic zymographies. HI was achieved by unilateral carotid ligature followed by a 40 min hypoxia (8%O₂. Excitotoxic lesions were produced by intra parenchymal cortical (i.c. injections of 10 µg ibotenate (Ibo. Gel zymograms in WT cortex revealed progressive extinction of MMP-2 and MMP-9 activities near day 15 or day 8 respectively. MMP-2 expression was the same in all strains while MMP-9 activity was barely detectable in t-PA⁻/⁻ and enhanced in PAI-1⁻/⁻ mice. HI or Ibo produced activation of MMP-2 activities 6 hours post-insult, in cortices of WT mice but not in t-PA⁻/⁻ mice. In PAI-1⁻/⁻ mice, HI or vehicle i.c. injection increased MMP-2 and MMP-9 activities. In situ zymograms using DQ-gelatin revealed vessel associated gelatinolytic activity in lesioned areas in PAI-1⁻/⁻ and in WT mice. In WT brain slices incubated ex vivo, glutamate (200 µM induced DQ-gelatin activation in vessels. The effect was not detected in t-PA⁻/⁻ mice, but was restored by concomitant exposure to recombinant t-PA (20 µg/mL. In summary, neonatal brain lesion paradigms and ex vivo excitotoxic glutamate evoked t-PA-dependent gelatinases activation in vessels. Both MMP-2 and MMP-9 activities appeared t-PA-dependent. The data suggest that vascular directed protease inhibition may have

  7. Alleviation of ischemia-induced brain edema by activation of the central histaminergic system in rats.

    Science.gov (United States)

    Irisawa, Yumi; Adachi, Naoto; Liu, Keyue; Arai, Tatsuru; Nagaro, Takumi

    2008-09-01

    We have reported that facilitation of central histaminergic activity prevents the development of ischemia-induced brain injury. Since cerebral edema is a major cause of brain damage, we studied effects on brain edema of postischemic administration of L-histidine, a precursor of histamine, and thioperamide, a histamine H(3)-receptor antagonist, both of which enhance central histaminergic activity. Focal cerebral ischemia for 2 h was provoked by transient occlusion of the right middle cerebral artery in rats, and the water content and infarct size were determined 24 h after reperfusion. Changes in the extracellular concentration of histamine were examined in the striatum by a microdialysis procedure, and effects of these compounds were evaluated. Repeated administration of L-histidine (1000 mg/kg x 2, i.p.), immediately and 6 h after reperfusion, reduced the increase in the water contents in ischemic regions. Simultaneous administration of thioperamide (5 mg/kg, s.c.) with L-histidine (1000 mg/kg, i.p.) completely prevented edema formation and alleviated brain infarction, although a single dose of L-histidine, immediately after reperfusion, showed no benefits. The striatal histamine level was gradually increased after reperfusion as well as during ischemia. Simultaneous administration of thioperamide with L-histidine markedly increased the brain histamine concentration, and the value increased up to 230% of that in the saline group 5 - 6 h after reperfusion. L-Histidine alone did not affect the increase in the histamine output after ischemia. These findings suggest that further activation of the central histaminergic system after initiation of cerebral ischemia prevents development of ischemia-induced brain edema.

  8. Association of the interleukin 1 beta gene and brain spontaneous activity in amnestic mild cognitive impairment

    Directory of Open Access Journals (Sweden)

    Zhuang Liying

    2012-12-01

    Full Text Available Abstract Purpose The inflammatory response has been associated with the pathogenesis of Alzheimer’s disease (AD. The purpose of this study is to determine whether the rs1143627 polymorphism of the interleukin-1 beta (IL-1β gene moderates functional magnetic resonance imaging (fMRI-measured brain regional activity in amnestic mild cognitive impairment (aMCI. Methods Eighty older participants (47 with aMCI and 33 healthy controls were recruited for this study. All of the participants were genotyped for variant rs1143627 in the IL1B gene and were scanned using resting-state fMRI. Brain activity was assessed by amplitude of low-frequency fluctuation (ALFF. Results aMCI patients had abnormal ALFF in many brain regions, including decreases in the inferior frontal gyrus, the superior temporal lobe and the middle temporal lobe, and increases in the occipital cortex (calcarine, parietal cortex (Pcu and cerebellar cortex. The regions associated with an interaction of group X genotypes of rs1143627 C/T were the parietal cortex (left Pcu, frontal cortex (left superior, middle, and medial gyrus, right anterior cingulum, occipital cortex (left middle lobe, left cuneus and the bilateral posterior lobes of the cerebellum. Regarding the behavioral significance, there were significant correlations between ALFF in different regions of the brain and with the cognitive scores of each genotype group. Conclusions The present study provided evidence that aMCI patients had abnormal ALFF in many brain regions. Specifically, the rs1143627 C/T polymorphism of the IL1B gene may modulate regional spontaneous brain activity in aMCI patients.

  9. Brain activity during interval timing depends on sensory structure.

    Science.gov (United States)

    Pfeuty, Micha; Ragot, Richard; Pouthas, Viviane

    2008-04-14

    Precise timing is crucial for accurate perception and action in the range of hundreds of milliseconds. One still unresolved question concerns the influence of sensory information content on timing mechanisms. Numerous studies have converged to suggest that the CNV (Contingent Negative Variation), a slow negative wave that develops between two events, notably reflects temporal processing of the interval between these two events. The present study aimed at investigating CNV activity in duration discrimination tasks using either filled (continuous tones) or empty intervals (silent periods bounded by two brief tones). Participants had to compare a test duration with a 600-ms standard. Time perception was markedly better in the 'empty' than in the 'filled' condition. Electrophysiological analyses performed on the longest test duration (794 ms) of the comparison phase revealed an effect of the sensory structure on both the CNV amplitude and CNV time-course. The CNV amplitude was larger for filled than for empty intervals, suggesting a superimposition of timing-dependent activity and sensory sustained activity. Furthermore, the CNV time-course paralleled the temporal structure of the memorized sensory event: for filled intervals, the CNV amplitude stopped increasing at 600 ms, i.e. the expected end of the continuous tone; for empty intervals, in contrast, the CNV amplitude precisely increased at 600 ms, i.e. the expected onset of the second brief tone. These results suggest that the CNV reflects the mental rehearsal of the memorized sensory event, in line with the idea that temporal processing in the sub-second range is based on sensory information.

  10. Effects of endosulfan on brain acetylcholinesterase activity in juvenile bluegill sunfish

    International Nuclear Information System (INIS)

    The effects of endosulfan upon brain acetylcholinesterase (AChE) activity were measured in juvenile blue gill sunfish (Lepomis macrochirus). Based on exposure durations of 0, 24, 48, 72, and 96 h and 1 week at 1.0 μg/L (just below the LC50 of 1.2 μg/L for this species), step-wise decreases in AChE activity were noted, corresponding to 0%, 3.57%, 12.65%, 14.23%, 16.31%, and 3.11% inhibition, respectively. Total brain protein concentrations were measured to test the accuracy of the Ache data with no significant anomalies. The duration of exposure was related to the reduction in the AChE activities which reflected the biotoxicity of endosulfan. The changes in the AChE activities will certainly affect the normal behavior of the juvenile blue gill which is detrimental to their very existence in the natural habitat

  11. Developmental competence of parthenogenetic mouse and human embryos after chemical or electrical activation.

    Science.gov (United States)

    Versieren, Karen; Heindryckx, Björn; Lierman, Sylvie; Gerris, Jan; De Sutter, Petra

    2010-12-01

    Parthenogenetic reconstruction is one major strategy to create patient-specific stem cells. The aim of this study was to find the best artificial activation protocol for parthenogenetic activation of mouse and human oocytes comparing different methods. In a first set of experiments, in-vivo matured mouse oocytes and human failed-fertilized, in-vitro and in-vivo matured oocytes were artificially activated by a chemical (ionomycin) or electrical stimulus. In a second set of experiments, a combination of activating agents (electrical pulses followed by ionomycin or SrCl(2)) was applied in an aim to improve developmental competence. All embryos were evaluated daily until day 6 after activation. Mouse blastocysts were differentially stained to evaluate blastocyst quality. For mouse oocytes and human failed-fertilized oocytes, blastocyst development was significantly higher after electrical activation (P<0.05). For human in-vitro and in-vivo matured oocytes, blastocyst formation was only obtained after electrical activation of in-vitro matured oocytes. After combining activating agents, no differences in development could be observed. In conclusion, this study revealed that for both mouse and human oocytes development to the blastocyst stage was significantly better after electrical activation compared with chemical activation. Combining activating agents had no further positive effect on developmental potential.

  12. Trpc2 gene impacts on maternal aggression, accessory olfactory bulb anatomy, and brain activity

    OpenAIRE

    Hasen, Nina S.; Gammie, Stephen C.

    2009-01-01

    The trpc2 gene codes for an ion channel found in the vomeronasal organ (VNO). Studies using the trpc2−/− (KO) mouse have exploited the gene's role in signal transduction to explore the VNO's role in pheromonally-mediated behaviors. To date, no study has evaluated the impact of the trpc2 gene on activity within the brain. Here, we examine the gene's effect on brain regions governing maternal aggression. We intruder-tested lactating dams and then quantified Fos immunoreactivity (Fos-IR) in the ...

  13. Recent development in noninvasive brain activity measurement by functional magnetic resonance imaging (fMRI)

    International Nuclear Information System (INIS)

    fMRI (functional magnetic resonance imaging) is a non-invasive brain imaging technique with which the distribution of neural activity is estimated by measuring local blood flow changes. Blood-oxygenation-level-dependent (BOLD) method measures changes in the density of deoxidized hemoglobin in blood caused by blood flow changes, while other methods have been developed to measure the blood flow changes directly. Effort has been expended to realize a submillimeter spatial resolution by using higher static magnetic field. fMRI has been carried out with various mental tasks, and many important findings have been made on the localization of higher brain functions. (author)

  14. Pinostrobin from Cajanus cajan (L.) Millsp. inhibits sodium channel-activated depolarization of mouse brain synaptoneurosomes.

    Science.gov (United States)

    Nicholson, Russell A; David, Laurence S; Pan, Rui Le; Liu, Xin Min

    2010-10-01

    This investigation focuses on the in vitro neuroactive properties of pinostrobin, a substituted flavanone from Cajanus cajan (L.) Millsp. of the Fabaceae family. We demonstrate that pinostrobin inhibits voltage-gated sodium channels of mammalian brain (IC(50)=23 µM) based on the ability of this substance to suppress the depolarizing effects of the sodium channel-selective activator veratridine in a synaptoneurosomal preparation from mouse brain. The resting membrane potential of synaptoneurosomes was unaffected by pinostrobin. The pharmacological profile of pinostrobin resembles that of depressant drugs that block sodium channels. PMID:20472040

  15. Brain Activation During Working Memory Is Altered in Patients With Type 1 Diabetes During Hypoglycemia

    OpenAIRE

    McCartney, Richard L.; Flores, Veronica; Bolo, Nicolas R.; Musen, Gail; Jacobson, Alan Marc; Weinger, Katie; Renshaw, Perry Franklin; Simonson, Donald Craig

    2011-01-01

    OBJECTIVE To investigate the effects of acute hypoglycemia on working memory and brain function in patients with type 1 diabetes. RESEARCH DESIGN AND METHODS Using blood oxygen level–dependent (BOLD) functional magnetic resonance imaging during euglycemic (5.0 mmol/L) and hypoglycemic (2.8 mmol/L) hyperinsulinemic clamps, we compared brain activation response to a working-memory task (WMT) in type 1 diabetic subjects (n = 16) with that in age-matched nondiabetic control subjects (n = 16). Beh...

  16. Effect of Instruction Based on Conceptual Change Activities on Students' Understanding of Static Electricity Concepts

    Science.gov (United States)

    Baser, Mustafa; Geban, Omer

    2007-01-01

    This study was conducted to investigate the effectiveness of learning activities based on conceptual change conditions and traditionally designed physics instruction on tenth-grade students' understanding of static electricity concepts and their attitudes toward physics as a school subject. Misconceptions related to static electricity concepts…

  17. Event-Related Beta EEG Changes During Active, Passive Movement and Functional Electrical Stimulation of the Lower Limb.

    Science.gov (United States)

    Qiu, Shuang; Yi, Weibo; Xu, Jiapeng; Qi, Hongzhi; Du, Jingang; Wang, Chunfang; He, Feng; Ming, Dong

    2016-02-01

    A number of electroencephalographic (EEG) studies have reported on event-related desynchronization/synchronization (ERD/ERS) during active movements, passive movements, and the movements induced by functional electrical stimulation (FES). However, the quantitative differences in ERD values and affected frequency bands associated with the lower limb have not been discussed. The goal of this paper was to quantitatively compare the ERD patterns during active movement, passive movement and FES-induced movement of the lower limb. 64-channel EEG signals were recorded to investigate the brain oscillatory patterns during active movement, passive movement and FES-induced movement of the lower limb in twelve healthy subjects. And passive movement and FES-induced movement were also performed in a hemiplegic stroke patient. For healthy subjects, FES-induced movement presented significantly higher characteristic frequency of central beta ERD while there was no significant difference in ERD values compared with active or passive movement. Meanwhile, beta ERD values of FES-induced movement were significantly correlated with those of active movement, and spatial distribution of beta ERD pattern for FES-induced movement was more correlated with that for active movement. In addition, the stroke patient presented central ERD patterns during FES-induced movement, while no ERD with similar frequencies could be found during passive movement. This work implies that the EEG oscillatory pattern under FES-induced movement tends more towards active movement instead of passive movement. The quantification of ERD patterns could be expected as a potential technique to evaluate the brain response during FES-induced movement. PMID:26441422

  18. Differential brain activity states during the perception and nonperception of illusory motion as revealed by magnetoencephalography

    OpenAIRE

    Crowe, David A.; Leuthold, Arthur C.; Georgopoulos, Apostolos P.

    2010-01-01

    We studied visual perception using an annular random-dot motion stimulus called the racetrack. We recorded neural activity using magnetoencephalography while subjects viewed variants of this stimulus that contained no inherent motion or various degrees of embedded motion. Subjects reported seeing rotary motion during viewing of all stimuli. We found that, in the absence of any motion signals, patterns of brain activity differed between states of motion perception and nonperception. Furthermor...

  19. Methionine sulfoxide reductase regulates brain catechol-O-methyl transferase activity

    OpenAIRE

    Moskovitz, Jackob; Walss-Bass, Consuelo; Cruz, Dianne A.; Thompson, Peter M.; Bortolato, Marco

    2014-01-01

    Catechol-O-methyl transferase (COMT) plays a key role in the degradation of brain dopamine (DA). Specifically, low COMT activity results in higher DA levels in the prefrontal cortex (PFC), thereby reducing the vulnerability for attentional and cognitive deficits in both psychotic and healthy individuals. COMT activity is markedly reduced by a non-synonymous SNP that generates a valine-to-methionine substitution on the residue 108/158, by means of as-yet incompletely understood posttranslation...

  20. The effects of physical activity and exercise on brain-derived neurotrophic factor in healthy humans

    DEFF Research Database (Denmark)

    Huang, T; Larsen, K T; Ried-Larsen, M;

    2014-01-01

    The purpose of this study was to summarize the effects of physical activity and exercise on peripheral brain-derived neurotrophic factor (BDNF) in healthy humans. Experimental and observational studies were identified from PubMed, Web of Knowledge, Scopus, and SPORT Discus. A total of 32 articles...... studies suggested an inverse relationship between the peripheral BDNF level and habitual physical activity or cardiorespiratory fitness. More research is needed to confirm the findings from the observational studies....